Geologic and physiographic controls on bed-material yield, transport, and channel morphology for alluvial and bedrock rivers, western Oregon

NASA Astrophysics Data System (ADS)

O'Connor, J. E.; Wallick, R.; Mangano, J.; Anderson, S. W.; Jones, K. L.; Keith, M. K.

2012-12-01

The rivers of western Oregon have channel beds ranging from fully alluvial to bedrock. A local history of in-stream gravel mining in conjunction with ongoing permitting concerns with respect to future extraction have prompted a series of investigations of bed-material production, transport and channel morphology across this spectrum of channel types. In western Oregon, it appears that the distribution of alluvial and bedrock channels (and many aspects of river morphology and behavior) are largely controlled by regional lithologies and the downstream consequences of different rates of bed-material supply and clast comminution. In particular, the Klamath Terrane has elevated erosion rates, steep slopes, and rock types resistant to abrasion, resulting in gravel-bed alluvial channels with high bed-material transport rates. By contrast, Coast Range drainages underlain by large areas of soft sedimentary rocks have bedrock channels owing to exceptionally rapid rates of bed-material attrition during transport. The resulting spatially distributed network controls on the distribution of alluvial and non-alluvial channels likely complicate linkages between rock uplift, bedrock incision, bed-material grain size, and profile concavity. Additionally, the alluvial channels have distinct morphologic characteristics, some of which relate strongly to transport rates. In particular, bar area correlates with estimates of bed-material flux, and this correlation is an upper bound for bar-area observations for non-alluvial reaches. Similarly, an index for transport capacity scaled by bed-material grain size correlates with estimated bed-material flux for alluvial rivers, but not for the non-alluvial rivers. Bedrock and mixed-bed channels in western Oregon have few evident broad-scale patterns or relations among reach-scale morphologic measurements or with estimated transport rates, perhaps indicating that very local lithologic, hydraulic and bed-material supply conditions exert more control on channel morphology.

Alluvium-Buttressed Landslides: Conceptual Model and Examples from California

NASA Astrophysics Data System (ADS)

Johnson, P. L.; Cotton, W. R., Sr.; Shires, P. O.

2016-12-01

Large, deep-seated landslides typically occur in hillside settings without any natural buttressing, and many of these landslides have relatively low factors of safety (FS), the ratio of driving to resisting forces. However, where deep-seated landslides failed millennia ago into valleys that subsequently experienced alluvial aggradation, a natural buttress of alluvium may be deposited over the landslide toe, increasing the FS of these landslides. The eustatic model for alluvial buttressing of Quaternary landslides involves failure of slopes during sea level low stand at or near the late Pleistocene last glacial maximum (LGM, approximately 20 ka). Following LGM, mean sea level rose by over 120m to its present elevation. This rise in base level resulted in deposition of alluvial sediment in coastal valleys that had been v-shaped and downcutting prior to and during LGM. These valleys now have broad, low gradient floors formed by alluvial sediment, and the thick alluvial strata filling these valleys cover the toes of late Pleistocene landslides. In this study, three examples of large, deep-seated Pleistocene landslides that are buttressed by alluvium are presented. The McCracken Hill Landslide in Orange County and the Potrero Canyon Landslide Complex in Monterey County are located approximately 1.5 and 6 km, respectively, from the modern Pacific shore and closely fit the eustatic model of alluvial buttressing. At Knights Valley, in the upper Russian River watershed of eastern Sonoma County, a deep-seated alluvium-buttressed landslide is located approximately 65 km from the modern shore (measured along the Russian River and its tributary stream). The alluvium in Knights Valley may have ponded due to late Quaternary tectonic uplift of hills west of the valley. Streams that cross these hills are incised into bedrock downstream from Knights Valley and approaching the Russian River. Thus, the Knights Valley example (of an alluvium-buttressed landslide) demonstrates a rare exception to the broadly applicable eustatic model.

Long-term interactions between man and the fluvial environment - case of the Diyala alluvial fan, Iraq

NASA Astrophysics Data System (ADS)

Heyvaert, Vanessa M. A.; Walstra, Jan; Mortier, Clément

2014-05-01

The Mesopotamian alluvial plain is dominated by large aggradading river systems (the Euphrates, Tigris and their tributaries), which are prone to avulsions. An avulsion can be defined as the diversion of flow from an existing channel onto the floodplain, eventually resulting in a new channel belt. Early civilizations depended on the position of rivers for their economic survival and hence the impact of channel shifts could be devastating (Wilkinson 2003; Morozova 2005; Heyvaert & Baeteman 2008). Research in the Iranian deltaic part of the Mesopotamian plain has demonstrated that deliberate human action (such as the construction of irrigation canals and dams) triggered or obstructed the alluvial processes leading to an avulsion on fluvial megafans (during preconditioning, triggering and post-triggering stages) (Walstra et al. 2010; Heyvaert et al. 2012, Heyvaert et al.2013). Thus, there is ample evidence that the present-day alluvial landscapes in the region are the result of complex interactions between natural and anthropogenic processes. Here we present a reconstruction of the Late Holocene evolution of the Diyala alluvial fan (one of the main tributaries of the Tigris in Iraq), with particular attention to the relations between alluvial fan development, changes in channel pattern, the construction of irrigation networks and the rise and collapse of societies through historic times. The work largely draws on the use of remote sensing and GIS techniques for geomorphological mapping, and previously published archaeological field data (Adams 1965). By linking archaeological sites of known age with traces of ancient irrigation networks we were able to establish a chronological framework of alluvial activity of the Diyala alluvial fan. Our results demonstrate that centralized and technologically advanced societies were able to maintain a rapidly aggradading distibutary channel system, supplying water and sediment across the entire alluvial fan. As a consequence, during these periods (Parthian, Sasanian and again in modern times), significant human modification of the landscape took place. Periods of societal decline are associated with reduced human impact and the development of a single-threaded incising river system. Adams, R.M. (1965). Land behind Baghdad: A history of settlement on the Diyala plains. University of Chicago Press, Chicago, Illinois. Heyvaert, V.M.A. & Baeteman, C. (2008). A Middle to Late Holocene avulsion history of the Euphrates river: a case study from Tell ed-D-er, Iraq, Lower Mesopotamia. Quaternary Science Reviews, 27, 2401-2410. Heyvaert, V. M. A., Walstra, J., Verkinderen, P., Weerts, H. J. T. & Ooghe, B. (2012). The role of human interference on the channel shifting of the river Karkheh in the Lower Khuzestan plain (Mesopotamia, SW Iran). Quaternary International, 251, 52-63. Heyvaert, V.M.A., Walstra, J., Weerts, H.J.T. (2013). Human impact on avulsion and fan development in a semi-arid region: examples from SW Iran. Abstractbook of the 10th International Fluvial Sedimentology Conference, July 2013,Leeds, United Kingdom. Morozova, G.S. (2005). A review of Holocene avulsions of the Tigris and Euphrates rivers and possible effects on the evolution of civilizations in lower Mesopotamia. Geoarchaeology, 20, 401-423. Walstra, J., Heyvaert, V. M. A. & Verkinderen, P. (2010). Assessing human impact on alluvial fan development: a multidisciplinary case-study from Lower Khuzestan (SW Iran). Geodinamica Acta, 23, 267-285. Wilkinson, T.J. (2003). Archaeological Landscapes of the Near East. The University of Arizona Press, Tucson, Arizona.

Cyclic Sediment Trading Between Channel and River Bed Sediments

NASA Astrophysics Data System (ADS)

Haddadchi, A.

2015-12-01

Much of the previous work on sediment tracing has focused on determining either the initial sources of the sediment (soils derive from a particular rock type) or the erosion processes generating the sediment. However, alluvial stores can be both a source and sink for sediment transported by streams. Here geochemical and fallout radionuclide tracing of river-bed and alluvial sediments are used to determine the role of secondary sources, sediment stores, as potential sources of sediment leaving Emu Creek catchment, southeastern Queensland, Australia. Activity concentrations of 137Cs on the river sediments are consistent with channel erosion being the dominant source at all sites sampled along the river. To characterise the deposition and remobilisation cycles in the catchment, a novel geochemical tracing approach was used. Successive pockets of alluvium were treated as discrete sink terms within geochemical mixing models and their source contributions compared with those of river bed sediments collected adjacent to each alluvial pocket. Three different size fractions were examined; silts and clays (<10 μm), silts (10-63 μm), and fine sands (63-212 μm). The contribution of the initial soil/rock type sources to river bed and alluvial sediments at each sampling site was identical for all three different size fractions, but varied along the stream. Combining these findings it is concluded that proximal alluvial stores dominated the supply of sediment to the river at each location, with this being particularly evident at the catchment outlet. Identical contribution of rock type sources to both river bed and alluvial pockets together with the dominant erosion being from channel banks indicates a high degree of 'trading' between the fluvial space and the alluvial space. Hence, management works aimed at primarily reducing the supply of sediments to the outlet of Emu Creek should focus on rehabilitation of channel banks in the lower catchment.

Impacts of hydroelectric dams on alluvial riparian plant communities in Eastern Brazilian Amazonian.

PubMed

Ferreira, Leandro Valle; Cunha, Denise A; Chaves, Priscilla P; Matos, Darley C L; Parolin, Pia

2013-09-01

The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

Publications - PIR 2002-1C | Alaska Division of Geological & Geophysical

Science.gov Websites

fortymile_eaglea1_surficial Shapefile 3.3 M Metadata - Read me Keywords Alaska, State of; Alluvial Deposits; Bison Fossils ; Boundary (Place); Caribou Fossils; Cenozoic; Colluvial Deposits; Complex Deposits; Cretaceous; Devonian ; Fortymile Mining District; Fortymile River; Geologic Map; Geology; Glacial Deposits; Holocene; Horse Fossils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Lin; Dai, Zhenxue; Gong, Huili

Understanding the heterogeneity arising from the complex architecture of sedimentary sequences in alluvial fans is challenging. This study develops a statistical inverse framework in a multi-zone transition probability approach for characterizing the heterogeneity in alluvial fans. An analytical solution of the transition probability matrix is used to define the statistical relationships among different hydrofacies and their mean lengths, integral scales, and volumetric proportions. A statistical inversion is conducted to identify the multi-zone transition probability models and estimate the optimal statistical parameters using the modified Gauss–Newton–Levenberg–Marquardt method. The Jacobian matrix is computed by the sensitivity equation method, which results in anmore » accurate inverse solution with quantification of parameter uncertainty. We use the Chaobai River alluvial fan in the Beijing Plain, China, as an example for elucidating the methodology of alluvial fan characterization. The alluvial fan is divided into three sediment zones. In each zone, the explicit mathematical formulations of the transition probability models are constructed with optimized different integral scales and volumetric proportions. The hydrofacies distributions in the three zones are simulated sequentially by the multi-zone transition probability-based indicator simulations. Finally, the result of this study provides the heterogeneous structure of the alluvial fan for further study of flow and transport simulations.« less

Understory vegetation as an indicator for floodplain forest restoration in the Mississippi River Alluvial Valley, U.S.A

Treesearch

Diane De Steven; Stephen P. Faulkner; Bobby D. Keeland; Michael J. Baldwin; John W. McCoy; Steven C. Hughes

2015-01-01

In the Mississippi River Alluvial Valley (MAV), complete alteration of river-floodplain hydrology allowed for widespread conversion of forested bottomlands to intensive agriculture, resulting in nearly 80% forest loss. Governmental programs have attempted to restore forest habitat and functions within this altered landscape by the methods of tree planting (...

Statistic inversion of multi-zone transition probability models for aquifer characterization in alluvial fans

DOE PAGES

Zhu, Lin; Dai, Zhenxue; Gong, Huili; ...

2015-06-12

Understanding the heterogeneity arising from the complex architecture of sedimentary sequences in alluvial fans is challenging. This study develops a statistical inverse framework in a multi-zone transition probability approach for characterizing the heterogeneity in alluvial fans. An analytical solution of the transition probability matrix is used to define the statistical relationships among different hydrofacies and their mean lengths, integral scales, and volumetric proportions. A statistical inversion is conducted to identify the multi-zone transition probability models and estimate the optimal statistical parameters using the modified Gauss–Newton–Levenberg–Marquardt method. The Jacobian matrix is computed by the sensitivity equation method, which results in anmore » accurate inverse solution with quantification of parameter uncertainty. We use the Chaobai River alluvial fan in the Beijing Plain, China, as an example for elucidating the methodology of alluvial fan characterization. The alluvial fan is divided into three sediment zones. In each zone, the explicit mathematical formulations of the transition probability models are constructed with optimized different integral scales and volumetric proportions. The hydrofacies distributions in the three zones are simulated sequentially by the multi-zone transition probability-based indicator simulations. Finally, the result of this study provides the heterogeneous structure of the alluvial fan for further study of flow and transport simulations.« less

Hydrodynamic controls on the long-term construction of large river floodplains and alluvial ridges

NASA Astrophysics Data System (ADS)

Nicholas, Andrew; Aalto, Rolf; Sambrook Smith, Gregory; Schwendel, Arved

2017-04-01

Floodplain construction involves the interplay between channel belt sedimentation and avulsion, overbank deposition of fines, and sediment reworking by channel migration. Each of these processes is controlled, in part, by within-channel and/or overbank hydraulics. However, while spatially-distributed hydrodynamic models are used routinely to simulate floodplain inundation and overbank sedimentation during individual floods, most existing models of long-term floodplain construction and alluvial architecture do not account for flood hydraulics explicitly. Instead, floodplain sedimentation is typically modelled as an exponential function of distance from the river, and avulsion thresholds are defined using topographic indices that quantify alluvial ridge morphology (e.g., lateral:downstream slope ratios or metrics of channel belt super-elevation). Herein, we apply a hydraulically driven model of floodplain evolution, in order to quantify the controls on alluvial ridge construction and avulsion likelihood in large lowland rivers. We combine a simple model of meander migration and cutoff with a 2D grid-based model of flood hydrodynamics and overbank sedimentation. The latter involves a finite volume solution of the shallow water equations and an advection-diffusion model for suspended sediment transport. The model is used to carry out a series of numerical experiments to investigate floodplain construction for a range of flood regimes and sediment supply scenarios, and results are compared to field data from the Rio Beni system, northern Bolivia. Model results, supported by field data, illustrate that floodplain sedimentation is characterised by a high degree of intermittency that is driven by autogenic mechanisms (i.e. even in the absence of temporal variations in flood magnitude and sediment supply). Intermittency in overbank deposits occurs over a range of temporal and spatial scales, and is associated with the interaction between channel migration dynamics and crevasse splay formation. Moreover, alluvial ridge construction, by splay deposition, is controlled by the balance between in-channel and overbank sedimentation rates, and by ridge reworking linked to channel migration. The resulting relationship between sedimentation rates, ridge morphology and avulsion likelihood is more complex than that which is incorporated with existing models of long-term floodplain construction that neglect flood hydraulics. These results have implications for the interpretation of floodplain deposits as records of past flood regimes, and for the controls on the alluvial architecture of large river floodplains.

Herbicides and herbicide degradates in shallow groundwater and the Cedar River near a municipal well field, Cedar Rapids, Iowa

USGS Publications Warehouse

Boyd, R.A.

2000-01-01

Water samples were collected near a Cedar Rapids, Iowa municipal well field from June 1998 to August 1998 and analyzed for selected triazine and acetanilide herbicides and degradates. The purpose of the study was to evaluate the occurrence of herbicides and herbicide degradates in the well field during a period following springtime application of herbicides to upstream cropland. The well field is in an alluvial aquifer adjacent to the Cedar River. Parent herbicide concentrations generally were greatest in June, and decreased in July and August. Atrazine was most frequently detected and occurred at the greatest concentrations; acetochlor, cyanazine and metolachlor also were detected, but at lesser concentrations than atrazine. Triazine degradate concentrations were relatively small (<0.50 ??g/l) and generally decreased from June to August. Although the rate of groundwater movement is relatively fast (approx. 1 m per day) in the alluvial aquifer near the Cedar River, deethylatrazine (DEA) to atrazine ratios in groundwater samples collected near the Cedar River indicate that atrazine and DEA probably are gradually transported into the alluvial aquifer from the Cedar River. Deisopropylatrazine (DIA) to DEA ratios in water samples indicate most DIA in the Cedar River and alluvial aquifer is produced by atrazine degradation, although some could be from cyanazine degradation. Acetanilide degradates were detected more frequently and at greater concentrations than their corresponding parent herbicides. Ethanesulfonic-acid (ESA) degradates comprised at least 80% of the total acetanilide-degradate concentrations in samples collected from the Cedar River and alluvial aquifer in June, July and August; oxanilic acid degradates comprised less than 20% of the total concentrations. ESA-degradate concentrations generally were smallest in June and greater in July and August. Acetanilide degradate concentrations in groundwater adjacent to the Cedar River indicate acetanilide degradates are transported into the alluvial aquifer in a manner similar to that indicated for atrazine and DEA. Copyright (C) 2000 Elsevier Science B.V.

Spatial discontinuity and temporal evolution of channel morphology along a mixed bedrock-alluvial river, upper Drôme River, southeast France: Contingent responses to external and internal controls

NASA Astrophysics Data System (ADS)

Toone, J.; Rice, S. P.; Piégay, H.

2014-01-01

The rehabilitation of degraded river channels is often guided by assumptions of continuity, yet in response to spatial and temporal variations in controlling conditions rivers typically display discontinuous response in space and time. This study examines the development of a 5 km reach of the Drôme River, S.E. France, characterised by alternating alluvial and bedrock zones that are separated by abrupt downstream transitions. This reach is representative of the Drôme River as a whole, and other rivers in the European Alps where braided channel planforms have been replaced by more complex, discontinuous morphologies. The primary aims are to understand how this spatial complexity has developed on the Drôme; evaluate how temporal channel changes have been affected by local factors, particularly bedrock exposures, and by long-term, catchment-scale changes in sediment supply and the flood activity; and consider the implications of this discontinuous geomorphology for reach management. The development of geomorphological zonation is examined by documenting sequential changes in channel planform between seven periods, using aerial photography (1948-2006) and by analysing change in bed elevation from profiles surveyed in 1928, 2003 and 2005. Between 1948 and 2001 bedrock exposed in the channel bed and along the floodplain margins defined discontinuities in sediment connectivity that were largely responsible for the configuration of channel zones. The impact of floods on this system was not proportional to flood magnitude. A modest flood in 1978 was an important event that, by incision and avulsion at key locations, defined a pattern of zonation that persisted until the end of the study in 2006. During the final 5 years of the study, alluvial zones that previously responded to large floods by widening underwent narrowing, despite the occurrence of a large flood, and led to an overall reduction in width variance. This resulted from progressive incision beneath and disconnection from formerly active channel areas, in response to long-term, catchment-scale reductions in sediment supply and flood frequency. In 2006 the pattern of zonation remains distinct, disguising this recent change in channel response and underlining the need for long-term and sequential perspectives of channel development to fully understand the processes in operation; contemporary snapshots of channel form may be misleading. Understanding interactions between inherent channel complexity and prevailing flow and sediment conditions, and how this shapes channel response to individual floods, is essential when interpreting future trajectories of channel change and likely response to management intervention.

INFILTRATION OF ATRAZINE AND METABOLOTES FROM A STREAM TO AN ALLUVIAL AQUIFER

EPA Science Inventory

The infiltration of atrazine, deethylatrazine, and deisopropylatrazine from Walnut Creek, a tributary stream, to the alluvial valley aquifer along the South Skunk River in central Iowa occurred where the stream transects the river's flood plain. A preliminary estimate indicated t...

Recharge of shallow aquifers through two ephemeral-stream channels in northeastern Wyoming, 1982-1983

USGS Publications Warehouse

Lenfest, L.W.

1987-01-01

Quantifying the recharge from ephemeral streams to alluvial and bedrock aquifers will help evaluate the effects of surface mining on alluvial valley floors in Wyoming. Two stream reaches were chosen for study in the Powder River basin. One reach was located along the North Fork Dry Fork Cheyenne River near Glenrock, Wyoming, and the other reach was located along Black Thunder Creek near Hampshire, Wyoming. The reach along the North Fork Dry Fork Cheyenne River was instrumented with 3 gaging stations to measure streamflow and with 6 observation wells to measure groundwater level fluctuations in alluvial and bedrock aquifers in response to streamflow. The 3 streamflow gaging stations were located within the 2.5-mi study reach to measure the approximate gain or loss of discharge along the reach. Computed streamflow losses ranged from 0.43 acre-ft/mi on July 9 , 1982, to 1.44 acre-ft/mi on August 9, 1982. The observation wells completed only in the alluvial aquifer were dry during flow in the North Fork Dry Fork Cheyenne River, whereas water levels in half of the observation wells completed in the bedrock aquifers or the alluvial and bedrock aquifers rose in response to flow in the North Fork Dry Fork Cheyenne River. Groundwater recharge on August 9, 1982, was calculated using a convolution technique using groundwater levels at the upstream site and was estimated to be 26.5 acre-ft/mi. The reach along Black Thunder Creek was instrumented with one gaging station to measure streamflow and with 4 observation wells to measure water level response in alluvial and bedrock aquifers to streamflow. Recharge to the alluvial aquifer from flow in Black Thunder Creek ranged from 3.56 to 12.4 acre-ft/mi. The recharge was estimated using the convolution technique using water level measurements in the observation wells completed in the alluvial aquifer. Water level measurements in the observation wells indicated water level rises in the alluvial and bedrock aquifers in response to flow in Black Thunder Creek. (Author 's abstract)

Dam impacts on and restoration of an alluvial river-Rio Grande, New Mexico

Treesearch

Gigi Richard; Pierre Julien

2003-01-01

The impact of construction of dams and reservoirs on alluvial rivers extends both upstream and downstream of the dam. Downstream of dams, both the water and sediment supplies can be altered leading to adjustments in the river channel geometry and ensuing changes in riparian and aquatic habitats. The wealth of pre and post-regulation data on the Middle Rio Grande, New...

Effectiveness of an alluvial wetland on improving ground-water quality in a municipal well field, Cedar Rapids, Iowa, 1998-2006

USGS Publications Warehouse

Schnoebelen, Douglas J.

2008-01-01

An alluvial wetland proved useful in improving water quality. Samples from observation wells completed in the alluvial wetland near the municipal well field had nitrate concentrations that were four to six times lower when compared to river or upland sites; however, iron and manganese concentrations in samples from observation wells in the wetland areas were an order of magnitude higher when compared to the river or an upgradient well. Biological and chemical reduction processes were determined to mobilize inorganic constituents in accordance with physical chemistry principles. Generally, selected pesticides and two pesticide degradates of atrazine that were sampled for in alluvial wetland wells remained relatively unchanged, and indicated only a slight decrease in concentration compared to the Cedar River water samples. Pesticides were not detected above regulatory limits in any of the observation wells; however, one sample from the Cedar River had an atrazine detection at 4.5 micrograms per liter, which is above the maximum contaminant level of 3.0 micrograms per liter for drinking-water regulations for that compound. Results indicate that alluvial wetlands may provide substantial reductions of nitrate concentrations in ground water, and may be a useful strategy for the reduction of nitrate for municipal wells. Results for reducing pesticides were less dramatic than for nitrate, as pesticide concentrations were reduced slightly from the river to the wetland.

Stages of the development of alluvial soils in the Bikin River valley (the Amur River basin) in the Middle and Late Holocene

NASA Astrophysics Data System (ADS)

Nazarkina, A. V.; Belyanin, P. S.

2014-05-01

The evolution of alluvial soils in the Bikin River basin in the Middle and the Late Holocene is discussed. On the basis of biostratigraphic data, four pollen zones have been identified in the soils: Pinus koraiensis- Picea, Pinus koraiensis- Quercus- Sphagnum, Betula- Alnus- Alnaster, and Quercus. A set of soil characteristics (texture, acid-base properties, and the organic matter content and group composition) have also been determined. These data allow us to distinguish between four stages of alluvial soil formation in the Bikin River basin. They characterize humus-forming conditions in the Middle and the Late Holocene. Reconstruction of ancient vegetation conditions makes it possible to conclude that climatic fluctuations were synchronous with changes in the soil characteristics. During the Holocene climatic optimum, humus was formed in a slightly acid medium, and humic acids predominated. In cold periods with increased precipitation, fulvic acids predominated in the composition of humus, and the portion of insoluble residue was high because of the more acid medium. The stages of alluvial pedogenesis in the Bikin River valley follow the sedimentation model of soil evolution. Alluvial gray humus soils evolved from typical gray humus soils under meadow communities during warm periods to gleyic and gleyed soils under birch shrubs and alder groves in colder and wetter periods.

The role of rivers in ancient societies, or how man transformed the alluvial landscapes of Khuzestan (SW Iran)

NASA Astrophysics Data System (ADS)

Walstra, J.; Heyvaert, V.; Verkinderen, P.

2012-04-01

For many thousands of years the alluvial plains of Khuzestan (SW Iran) have been subject to intensive settlement and agriculture. Ancient societies depended on the position of major rivers for their economic survival and hence, there is ample evidence of human activities trying to control the distribution of water. Throughout the plains ancient irrigation and settlement patterns are visible, although traces are rapidly disappearing due to expanding modern land use. Aim of this study is to unlock and integrate the rich information on landscape and archaeology, which only survives through the available historical imagery and some limited archaeological surveys. A GIS-based geomorphological mapping procedure was developed, using a variety of imagery, including historical aerial photographs, CORONA, Landsat and SPOT images. In addition, supported by the evidence from previous geological field surveys, archaeological elements were identified, mapped and included in a GIS database. The resulting map layers display the positions of successive palaeochannel belts and extensive irrigation networks, together indicating a complex alluvial history characterized by avulsions and significant human impact. As shown in several case-studies, integrating information from multiple disciplines provides valuable insights in the complex landscape evolution of this region, both from geological and historical perspectives. Remote sensing and GIS are essential tools in such a research context. The presented work was undertaken within the framework of the Interuniversity Attraction Pole "Greater Mesopotamia: Reconstruction of its Environment and History" (IAP 6/34), funded by the Belgian Science Policy.

Groundwater monitoring plan for the Missouri River alluvial aquifer in the vicinity of the City of Independence, Missouri, well field

USGS Publications Warehouse

Wilkison, Donald H.

2012-01-01

Source contributions to monitoring and supply wells, contributing recharge areas, groundwater travel times, and current (2012) understanding of alluvial water quality were used to develop a groundwater monitoring plan for the Missouri River alluvial aquifer in the vicinity of the City of Independence, Missouri well field. The plan was designed to evaluate long-term alluvial water quality and assess potential changes in, and threats to, well-field water quality. Source contributions were determined from an existing groundwater flow model in conjunction with particle-tracking analysis and verified with water-quality data collected from 1997 through 2010 from a network of 68 monitoring wells. Three conjunctive factors - well-field pumpage, Missouri River discharge, and aquifer recharge - largely determined groundwater flow and, therefore, source contributions. The predominant source of groundwater to most monitoring wells and supply wells is the Missouri River, and this was reflected, to some extent, in alluvial water quality. To provide an estimate of the maximum potential lead time available for remedial action, monitoring wells where groundwater travel times from the contributing recharge areas are less than 2 years and predominately singular sources (such as the Missouri River or the land surface) were selected for annual sampling. The sample interval of the remaining wells, which have varying travel times and intermediate mixtures of river and land-surface contributions, were staggered on a 2-, 3-, or 4-year rotation. This was done to provide data from similar contributing areas and account for inherent aquifer variability yet minimize sample redundancy.

The role of discharge variability in the formation and preservation of alluvial sediment bodies

NASA Astrophysics Data System (ADS)

Fielding, Christopher R.; Alexander, Jan; Allen, Jonathan P.

2018-03-01

Extant, planform-based facies models for alluvial deposits are not fully fit for purpose, because they over-emphasise plan form whereas there is little in the alluvial rock record that is distinctive of any particular planform, and because the planform of individual rivers vary in both time and space. Accordingly, existing facies models have limited predictive capability. In this paper, we explore the role of inter-annual peak discharge variability as a possible control on the character of the preserved alluvial record. Data from a suite of modern rivers, for which long-term gauging records are available, and for which there are published descriptions of subsurface sedimentary architecture, are analysed. The selected rivers are categorized according to their variance in peak discharge or the coefficient of variation (CVQp = standard deviation of the annual peak flood discharge over the mean annual peak flood discharge). This parameter ranges over the rivers studied between 0.18 and 1.22, allowing classification of rivers as having very low (< 0.20), low (0.20-0.40), moderate (0.40-0.60), high (0.60-0.90), or very high (> 0.90) annual peak discharge variance. Deposits of rivers with very low and low peak discharge variability are dominated by cross-bedding on various scales and preserve macroform bedding structure, allowing the interpretation of bar construction processes. Rivers with moderate values preserve mostly cross-bedding, but records of macroform processes are in places muted and considerably modified by reworking. Rivers with high and very high values of annual peak discharge variability show a wide range of bedding structures commonly including critical and supercritical flow structures, abundant in situ trees and transported large, woody debris, and their deposits contain pedogenically modified mud partings and generally lack macroform structure. Such a facies assemblage is distinctively different from the conventional fluvial style recorded in published facies models but is widely developed both in modern and ancient alluvial deposits. This high-peak-variance style is also distinctive of rivers that are undergoing contraction in discharge over time because of the gradual annexation of the channel belt by the establishment of woody vegetation. We propose that discharge variability, both inter-annual peak variation and "flashiness" may be a more reliable basis for classifying the alluvial rock record than planform, and we provide some examples of three classes of alluvial sediment bodies (representing low, intermediate, and high/very high discharge variability) from the rock record that illustrate this point.

Historical trajectories and restoration strategies for the Mississippi River alluvial valley

Treesearch

Brice B. Hanberry; John M. Kabrick; Hong S. He; Brian J. Palik

2012-01-01

Unlike upland forests in the eastern United States, little research is available about the composition and structure of bottomland forests before Euro-American settlement. To provide a historical reference encompassing spatial variation for the Lower Mississippi River Alluvial Valley, we quantified forest types, species distributions, densities, and stocking of...

Geologic and physiographic controls on bed-material yield, transport, and channel morphology for alluvial and bedrock rivers, western Oregon

USGS Publications Warehouse

O'Connor, James E.; Mangano, Joseph F.; Anderson, Scott A.; Wallick, J. Rose; Jones, Krista L.; Keith, Mackenzie K.

2014-01-01

The rivers of western Oregon have diverse forms and characteristics, with channel substrates ranging from continuous alluvial gravel to bare bedrock. Analysis of several measurable morphologic attributes of 24 valley reaches on 17 rivers provides a basis for comparing nonalluvial and alluvial channels. Key differences are that alluvial reaches have greater bar area, greater migration rates, and show systematic correlation among variables relating grain size to bed-material transport capacity. We relate these differences between channel types to bed-material transport rates as derived from a coupled regional analysis of empirical sediment yield measurements and physical experiments of clast attrition during transport. This sediment supply analysis shows that overall bed-material transport rates for western Oregon are chiefly controlled by (1) lithology and basin slope, which are the key factors for bed-material supply into the stream network, and (2) lithologic control of bed-material attrition from in-transport abrasion and disintegration. This bed-material comminution strongly affects bed-material transport in the study area, reducing transport rates by 50%–90% along the length of the larger rivers in the study area. A comparison of the bed-material transport estimates with the morphologic analyses shows that alluvial gravel-bed channels have systematic and bounding relations between bed-material transport rate and attributes such as bar area and local transport capacity. By contrast, few such relations are evident for nonalluvial rivers with bedrock or mixed-bed substrates, which are apparently more influenced by local controls on channel geometry and sediment supply. At the scale of western Oregon, the physiographic and lithologic controls on the balance between bed-material supply and transport capacity exert far-reaching influence on the distribution of alluvial and nonalluvial channels and their consequently distinctive morphologies and behaviors—differences germane for understanding river response to tectonics and environmental perturbations, as well as for implementing effective restoration and monitoring strategies.

Accounting System for Water Use by Vegetation in the Lower Colorado River Valley

USGS Publications Warehouse

Owen-Joyce, Sandra J.

1992-01-01

The Colorado River is the principal source of water in the valley of the Colorado River between Hoover Dam and the international boundary with Mexico (fig. 1). Agricultural, domestic, municipal, industrial, hydroelectric-power genera-tion, and recreation are the primary uses of river water in the valley. Most of the consumptive use of water from the river occurs downstream from Davis Dam, where water is diverted to irrigate crops along the river or is exported to interior regions of California and Arizona. Most of the agricultural areas are on the alluvium of the flood plain; in a few areas, land on the alluvial terraces has been cultivated. River water is consumed mainly by vegetation (crops and phreatophytes) on the flood plain. Crops were grown on 70.3 percent of the vegetated area classified by using 1984 digital image satellite data. Phreatophytes, natural vege-tation that obtain water from the alluvial aquifer, covered the remaining vegetated areas on the uncultivated flood plain. Most of the water used for irrigation is diverted or pumped from the river. In some areas, water is pumped from wells completed in the alluvial aquifer, which is hydraulically connected to the river.

Potential impacts of damming the Juba Valley, western Somalia: Insights from geomorphology and alluvial history

NASA Astrophysics Data System (ADS)

Williams, Martin

2014-05-01

In 1988 plans were well advanced to dam the Juba River in western Somalia. The aims of the Baardheere Dam Project were to generate hydroelectric power for the capital Mogadishu, and to provide water for irrigation in the Juba Valley. A reconnaissance survey on foot along 500 km of the river upstream of the proposed dam site at Baardheere and detailed geomorphic mapping from air photos provided a basis for reconstructing the late Quaternary alluvial history of the river and for assessing the potential impact of the proposed dam. The Juba River rises in the Ethiopian Highlands and is the only river in Somalia that flows to the sea. Its history reflects climatic events in Ethiopia, where the Rift Valley lakes were very low during the LGM (21±2 ka), and high for about 5, 000 years before and after then. Cave deposits in Somalia indicate wetter conditions at 13, 10, 7.5 and 1.5 ka. Alluvial terraces in the Juba Valley range in age from late Pleistocene to late Holocene but only attain a few metres above the present floodplain. This is because the dry tributary valleys contain limestone caves and fissures that divert any high flows from the parent river underground, a process not known when the project was first approved. The oldest preserved terrace was cemented by calcrete by 40 ka. Alluvial gravels were deposited at the outlet of dry tributary valleys during times of episodic high-energy flow between 26 ka and 28 ka. Finely laminated shelly sands accumulated at 10 ka to form the 5 m terrace. The 2 m terrace was laid down 3.2 ka ago as a slackwater deposit. The lack of high-level alluvial terraces raises doubts over plans to dam the river, since rapid leakage would occur from side valleys and the reservoir would not attain the height needed to generate hydroelectric power. It would submerge all existing arable land along the river. Finally, the presence in the late Holocene alluvium of the sub-fossil gastropods Bulinus truncatus and Biomphalaria pfeifferi, which are the two main vectors of schistosomiasis in northeast Africa, suggests that this parasitic disease could become endemic across the valley. Any future plans to manage the Juba River need to take proper account of alluvial history and geomorphic processes.

Effects of stream discharge, alluvial depth and bar amplitude on hyporheic flow in pool-riffle channels

Treesearch

Daniele Tonina; John M. Buffington

2011-01-01

Hyporheic flow results from the interaction between streamflow and channel morphology and is an important component of stream ecosystems because it enhances water and solute exchange between the river and its bed. Hyporheic flow in pool-riffle channels is particularly complex because of three-dimensional topography that spans a range of partially to fully submerged...

Runoff and Leaching of Metolachlor from Mississippi River Alluvial Soil during Seasons of Average and Below-Average Rainfall

USDA-ARS?s Scientific Manuscript database

The movement of metolachlor via runoff and leaching from plots planted to corn on Mississippi River alluvial soil (Commerce silt loam) was measured for a six-year period, 1995-2000. The first three years were characterized by normal rainfall volume, the second three years by reduced rainfall. The ...

Seedling Quality Standards for Bottomland Hardwood Afforestation in the Lower Mississippi River Alluvial Valley: Preliminary Results

Treesearch

Douglass F. Jacobs; Emile S. Gardiner; K. Francis Salifu; Ronald P. Overton; George Hernandez; M. Elizabeth Corbin; Kevyn E. Wightman; Marcus F. Selig

2005-01-01

Afforestation of bottomland hardwood species has increased in the Lower Mississippi River Alluvial Valley (LMRAV) in recent years. Rising demand for hardwood nursery stock and poor performance of some planted seedlings has created concern regarding the quality of seedlings currently available for afforestation in the LMRAV. Furthermore, no definitive guidelines for...

Flood control problems

USGS Publications Warehouse

Leopold, Luna Bergere; Maddock, Thomas

1955-01-01

Throughout the world, alluvial soils are among the most fertile and easiest cultivated. Alluvial valleys are routes for transportation either by water or by road and railroad. Rivers are sources of water, a necessity of life. But these river valleys and alluvial deposits, which have so many desirable characteristics and which have increased so greatly in population, are periodically occupied by the river in performing its task of removing the excess of precipitation from the land area and carrying away the products of erosion.How a river behaves and how the river flood plain appears depend on the relationships between water and sediment combined with the existing topography. Thus rivers and their alluvial deposits provide an endless variety of forms which are shaped, to a large extent, by the river flow during periods of rapid removal of debris and of excessive rainfall. The mechanics of river formation are such, however, that the highest discharges are not contained within a limited channel. How much water a channel will carry depends upon the frequency of occurrence of a flow. Low flows, which occur very frequently, are not important in channel formation. Neither are the infrequent discharges of very great magnitude which, although powerful, do not occur often enough to shape the channel. Channel characteristics, are dependent on those discharges of moderate size which combine power with frequency of occurrence to modify the channel from. In the highest discharges of a stream, water rises above the confines of its banks and flows over the flood plain.It must be considered, therefore, that floods are natural phenomena which are characteristic of all rivers. They perform a vital function in the maintenance of river forms and out of bank flow may be expected with a reasonable degree of regularity.

Statistical and Conceptual Model Testing Geomorphic Principles through Quantification in the Middle Rio Grande River, NM.

NASA Astrophysics Data System (ADS)

Posner, A. J.

2017-12-01

The Middle Rio Grande River (MRG) traverses New Mexico from Cochiti to Elephant Butte reservoirs. Since the 1100s, cultivating and inhabiting the valley of this alluvial river has required various river training works. The mid-20th century saw a concerted effort to tame the river through channelization, Jetty Jacks, and dam construction. A challenge for river managers is to better understand the interactions between a river training works, dam construction, and the geomorphic adjustments of a desert river driven by spring snowmelt and summer thunderstorms carrying water and large sediment inputs from upstream and ephemeral tributaries. Due to its importance to the region, a vast wealth of data exists for conditions along the MRG. The investigation presented herein builds upon previous efforts by combining hydraulic model results, digitized planforms, and stream gage records in various statistical and conceptual models in order to test our understanding of this complex system. Spatially continuous variables were clipped by a set of river cross section data that is collected at decadal intervals since the early 1960s, creating a spatially homogenous database upon which various statistical testing was implemented. Conceptual models relate forcing variables and response variables to estimate river planform changes. The developed database, represents a unique opportunity to quantify and test geomorphic conceptual models in the unique characteristics of the MRG. The results of this investigation provides a spatially distributed characterization of planform variable changes, permitting managers to predict planform at a much higher resolution than previously available, and a better understanding of the relationship between flow regime and planform changes such as changes to longitudinal slope, sinuosity, and width. Lastly, data analysis and model interpretation led to the development of a new conceptual model for the impact of ephemeral tributaries in alluvial rivers.

Upstream effects of dams on alluvial channels: state-of-the-art and future challenges

NASA Astrophysics Data System (ADS)

Liro, Maciej

2017-04-01

More than 50,000 large dams (with the height above 15 m) operate all over the world and, thus, they significantly disturb water and sediment transport in river systems. These disturbances are recognized as one of the most important factors shaping river morphology in the Anthropocene. Downstream effects of dams have been well documented in numerous case studies and supported by predictions from existing models. In contrast, little is known on the upstream effects of dams on alluvial channels. This review highlights the lack of studies on sedimentological, hydromorphological and biogeomorphological adjustments of alluvial rivers in the base-level raised zones of backwater upstream of dam reservoirs where water level fluctuations occur. Up to date, it has been documented that backwater effects may facilitate fine and coarse sediment deposition, increase groundwater level, provide higher and more frequent channel and floodplain inundation and lead to significant morphological changes. But there have been no studies quantifying short- and long-term consequences of these disturbances for the hydromorphological and biogeomorphological feedbacks that control development of alluvial channels. Some recent studies carried out on gravel-bed and fine-grained bed rivers show that the above mentioned disturbances facilitate vegetation expansion on exposed channel sediments and floodplain influencing river morphology, which suggests that backwater area of alluvial rivers may be treated as the hotspot of bio-geomorphological changes in a fluvial system. To set the stage for future research on upstream effects of dams, this work presents the existing state-of-art and proposes some hypotheses which may be tested in future studies. This study was carried out within the scope of the Research Project 2015/19/N/ST10/01526 financed by the National Science Centre of Poland

Evolution of the alluvial fans of the Luo River in the Weihe Basin, central China, controlled by faulting and climate change - A reevaluation of the paleogeographical setting of Dali Man site

NASA Astrophysics Data System (ADS)

Rits, Daniël S.; van Balen, Ronald T.; Prins, Maarten A.; Zheng, Hongbo

2017-06-01

The Luo River is located in the southern part of the Chinese Loess Plateau and the northern part of the Weihe Basin, in Central China. In the basin it flows proximal to the site of the Luyang Wetland core, which is an important archive of climate change over the past 1 Myr in this region. In this paper, the contribution of the Luo River to the sedimentary record is analyzed by reconstructing the evolution of this river during the Middle to Late Pleistocene. It is argued that an alluvial fan of the Luo River has contributed to the sedimentary archive until approximately 200-240 ka. From this moment onwards, the fan became incised and terraces began to form. The formation of a new alluvial fan further downstream led to the disconnection of the Luo River from the Luyang Wetland core site. We propose that this series of events was caused by the displacement of an intra-basinal fault and the resultant faulting-forced folding, which caused increased relative subsidence, and thus increased sedimentation rates at the core site. Therefore, a complete sediment record in the 'Luyang Wetland' was preserved, despite the disconnection from the Luo River. The chronology of the fans and terraces was established using existing age control (U-series, ESR, OSL, pIRIR290 and magnetic susceptibility correlation), and through correlation of the loess-paleosol cover to marine isotope stages. Based on sedimentological characteristics of the fluvial sequence, we suggest that incision of the Luo River occurred in two steps. Small incisions took place at transitions to interglacials and the main incision phases occur at the transition from an interglacial to glacial climate. Due to the incision, basal parts of the oldest Luo River alluvial fan are exposed, and it is in one of these exposures that the famous Dali Man skull was retrieved. This study shows that the Dali Man did not live on a river terrace as previously thought, but on an aggrading alluvial fan, during wet, glacial conditions.

Multi-tracer investigation of river and groundwater interactions: a case study in Nalenggele River basin, northwest China

NASA Astrophysics Data System (ADS)

Xu, Wei; Su, Xiaosi; Dai, Zhenxue; Yang, Fengtian; Zhu, Pucheng; Huang, Yong

2017-11-01

Environmental tracers (such as major ions, stable and radiogenic isotopes, and heat) monitored in natural waters provide valuable information for understanding the processes of river-groundwater interactions in arid areas. An integrated framework is presented for interpreting multi-tracer data (major ions, stable isotopes (2H, 18O), the radioactive isotope 222Rn, and heat) for delineating the river-groundwater interactions in Nalenggele River basin, northwest China. Qualitative and quantitative analyses were undertaken to estimate the bidirectional water exchange associated with small-scale interactions between groundwater and surface water. Along the river stretch, groundwater and river water exchange readily. From the high mountain zone to the alluvial fan, groundwater discharge to the river is detected by tracer methods and end-member mixing models, but the river has also been identified as a losing river using discharge measurements, i.e. discharge is bidirectional. On the delta-front of the alluvial fan and in the alluvial plain, in the downstream area, the characteristics of total dissolved solids values, 222Rn concentrations and δ18O values in the surface water, and patterns derived from a heat-tracing method, indicate that groundwater discharges into the river. With the environmental tracers, the processes of river-groundwater interaction have been identified in detail for better understanding of overall hydrogeological processes and of the impacts on water allocation policies.

Modeling the Long-term Planform Evolution of Meandering Rivers in Confined Alluvial Valleys: Etsch-Adige River, NE Italy.

NASA Astrophysics Data System (ADS)

Zen, S.; Bogoni, M.; Zolezzi, G.; Lanzoni, S.; Scorpio, V.

2016-12-01

We combine the use of a morphodynamic model for river meander planform evolution with a geological dataset to investigate the influence of external confinements on the long-term evolution of a meandering river flowing in an Alpine valley. The analysis focuses on a 100 km reach of the Adige River, NE Italy, which had several sinuous/meandering sections before being extensively channelized in the 1800s. Geological surveys and historical maps revealed that many sections of the study reach impinge on the borders of the valley during its evolution. Moreover, a marked spatial heterogeneity in floodplain vertical accretion rates likely reflects preferential positions of the river channel in the floodplain. Valley confinements are represented by bedrock outcrops and by alluvial fans created by lateral tributaries, and were extracted from the geological and historical maps to build the computational domain for the meander morphodynamic model. The model predicts the long-term planform evolution of a meandering river based on a linear solution of the 2D De St Venant-Exner differential system and can manage changes in floodplain erodibility. Model applications allow to isolate the effects of valley bedrock and of alluvial fans in constraining the lateral channel migration. Modeled river channel persistence maps are compared with the available geological information. The present work allows further insights into the role of external confinements to river meander belts, which have been conducted so far mostly assuming the channel to evolve in unconfined floodplains. Future research shall incorporate model components for floodplain vertical accretion rates and for the advancement of alluvial fans occurring at the same time scale considered for meander evolution.

Nursery stock quality as an indicator of bottomland hardwood forest restoration success in the Lower Mississippi River Alluvial Valley

Treesearch

Douglass F. Jacobs; Rosa C. Goodman; Emile S. Gardiner; K Frances Salifu; Ronald P. Overton; George Hernandez

2012-01-01

Seedling morphological quality standards are lacking for bottomland hardwood restoration plantings in the Lower Mississippi River Alluvial Valley, USA, which may contribute toward variable restoration success. We measured initial seedling morphology (shoot height, root collar diameter, number of first order lateral roots, fresh mass, and root volume), second year field...

A Simple Model to Describe the Relationship among Rainfall, Groundwater and Land Subsidence under a Heterogeneous Aquifer

NASA Astrophysics Data System (ADS)

Zheng, Y. Y.; Chen, Y. L.; Lin, H. R.; Huang, S. Y.; Yeh, T. C. J.; Wen, J. C.

2017-12-01

Land subsidence is a very serious problem of Zhuoshui River alluvial fan, Taiwan. The main reason of land subsidence is a compression of soil, but the compression measured in the wide area is very extensive (Maryam et al., 2013; Linlin et al., 2014). Chen et al. [2010] studied the linear relationship between groundwater level and subsurface altitude variations from Global Positioning System (GPS) station in Zhuoshui River alluvial fan. But the subsurface altitude data were only from two GPS stations. Their distributions are spared and small, not enough to express the altitude variations of Zhuoshui River alluvial fan. Hung et al. [2011] used Interferometry Synthetic Aperture Radar (InSAR) to measure the surface subsidence in Zhuoshui River alluvial fan, but haven't compared with groundwater level. The study compares the correlation between rainfall events and groundwater level and compares the correlation between groundwater level and subsurface altitude, these two correlation affected by heterogeneous soil. From these relationships, a numerical model is built to simulate the land subsidence variations and estimate the coefficient of aquifer soil compressibility. Finally, the model can estimate the long-term land subsidence. Keywords: Land Subsidence, InSAR, Groundwater Level, Numerical Model, Correlation Analyses

Coupling heat and chemical tracer experiments for estimating heat transfer parameters in shallow alluvial aquifers.

PubMed

Wildemeersch, S; Jamin, P; Orban, P; Hermans, T; Klepikova, M; Nguyen, F; Brouyère, S; Dassargues, A

2014-11-15

Geothermal energy systems, closed or open, are increasingly considered for heating and/or cooling buildings. The efficiency of such systems depends on the thermal properties of the subsurface. Therefore, feasibility and impact studies performed prior to their installation should include a field characterization of thermal properties and a heat transfer model using parameter values measured in situ. However, there is a lack of in situ experiments and methodology for performing such a field characterization, especially for open systems. This study presents an in situ experiment designed for estimating heat transfer parameters in shallow alluvial aquifers with focus on the specific heat capacity. This experiment consists in simultaneously injecting hot water and a chemical tracer into the aquifer and monitoring the evolution of groundwater temperature and concentration in the recovery well (and possibly in other piezometers located down gradient). Temperature and concentrations are then used for estimating the specific heat capacity. The first method for estimating this parameter is based on a modeling in series of the chemical tracer and temperature breakthrough curves at the recovery well. The second method is based on an energy balance. The values of specific heat capacity estimated for both methods (2.30 and 2.54MJ/m(3)/K) for the experimental site in the alluvial aquifer of the Meuse River (Belgium) are almost identical and consistent with values found in the literature. Temperature breakthrough curves in other piezometers are not required for estimating the specific heat capacity. However, they highlight that heat transfer in the alluvial aquifer of the Meuse River is complex and contrasted with different dominant process depending on the depth leading to significant vertical heat exchange between upper and lower part of the aquifer. Furthermore, these temperature breakthrough curves could be included in the calibration of a complex heat transfer model for estimating the entire set of heat transfer parameters and their spatial distribution by inverse modeling. Copyright © 2014 Elsevier B.V. All rights reserved.

River banks and channel axis curvature: Effects on the longitudinal dispersion in alluvial rivers

NASA Astrophysics Data System (ADS)

Lanzoni, Stefano; Ferdousi, Amena; Tambroni, Nicoletta

2018-03-01

The fate and transport of soluble contaminants released in natural streams are strongly dependent on the spatial variations of the flow field and of the bed topography. These variations are essentially related to the presence of the channel banks and to the planform configuration of the channel. Large velocity gradients arise near to the channel banks, where the flow depth decreases to zero. Moreover, single thread alluvial rivers are seldom straight, and usually exhibit meandering planforms and a bed topography that deviates from the plane configuration. Channel axis curvature and movable bed deformations drive secondary helical currents which enhance both cross sectional velocity gradients and transverse mixing, thus crucially influencing longitudinal dispersion. The present contribution sets up a rational framework which, assuming mild sloping banks and taking advantage of the weakly meandering character often exhibited by natural streams, leads to an analytical estimate of the contribution to longitudinal dispersion associated with spatial non-uniformities of the flow field. The resulting relationship stems from a physics-based modeling of the flow in natural rivers, and expresses the bend averaged longitudinal dispersion coefficient as a function of the relevant hydraulic and morphologic parameters. The treatment of the problem is river specific, since it relies on an explicit spatial description, although linearized, of the flow field that establishes in the investigated river. Comparison with field data available from tracer tests supports the robustness of the proposed framework, given also the complexity of the processes that affect dispersion dynamics in real streams.

Analysis of the Sediment Hydrograph of the alluvial deltas in the Apalachicola River, Florida

NASA Astrophysics Data System (ADS)

Daranpob, A.; Hagen, S.; Passeri, D.; Smar, D. E.

2011-12-01

Channel and alluvial characteristics in lowlands are the products of boundary conditions and driving forces. The boundary conditions normally include materials and land cover types, such as soil type and vegetation cover. General driving forces include discharge rate, sediment loadings, tides and waves. Deltas built up of river-transported sediment occur in depositional zones of the river mouth in flat terrains and slow currents. Total sediment load depends on two major abilities of the river, the river shear stress and capacity. The shear stress determines transport of a given sediment grain size, normally expressed as tractive force. The river capacity determines the total load or quantity of total sediments transported across a section of the river, generally expressed as the sediment loading rate. The shear stress and sediment loading rate are relatively easy to measure in the headwater and transfer zones where streams form a v-shape valley and the river begins to form defined banks compared to the deposition zone where rivers broaden across lower elevation landscapes creating alluvial forms such as deltas. Determinations of deposition and re-suspension of sediment in fluvial systems are complicated due to exerting tidal, wind, and wave forces. Cyclic forces of tides and waves repeatedly change the sediment transport and deposition rate spatially and temporally in alluvial fans. However, the influence decreases with water depth. Understanding the transport, deposition, and re-suspension of sediments in the fluvial zone would provide a better understanding of the morphology of landscape in lowland estuaries such as the Apalachicola Bay and its estuary systems. The Apalachicola River system is located in the Florida Panhandle. Shelf sedimentation process is not a strong influence in this region because it is protected by barrier islands from direct ocean forces of the Gulf of Mexico. This research explores the characteristic of suspended sediment loadings in fluvial zones of the Apalachicola River and its distributaries through field investigation and laboratory analysis of a series of total suspended solid (TSS) samples. Time-series TSS samples are collected at the alluvial zone. TSS and particle-size distribution analyses are performed to determine the TSS hydrograph and particle-size distribution of suspended solids. Relationships between the TSS hydrograph, discharge hydrograph, and tidal data provide a better understanding of the deposition and re-suspension of the fluvial system in the region. Total suspended particle-size distribution data are used to determine the deposition rate or diminishing rate of alluvial landform in the estuarine system. This dataset and analysis provide excellent information for future modeling work and wetland morphologic studies in the Apalachicola River and similar systems.

Patterns and Processes of Width Adjustment to Increased Streamflows in Semi-Alluvial Rivers

NASA Astrophysics Data System (ADS)

Kelly, S. A.; Belmont, P.

2015-12-01

While it is understood that river channel width is determined by fluxes of water and sediment, predictive models of channel width, and especially changes in width under non-stationary conditions, have proven elusive. Classic hydraulic geometry relations commonly used in numerical models and channel design typically scale width as a power law function of discharge, without consideration of bank properties. This study investigates the role of bank material in determining spatial and temporal variability in channel width and widening rates for semi-alluvial rivers that have experienced increases in flow. The 45,000 km2 Minnesota River Basin contains many semi-alluvial rivers that have been rapidly incising into fine-grained glacial deposits over the last 13,400 years in response to a catastrophic base level drop. Large, recent increases in streamflows have caused significant channel widening and migration, exacerbated erosion of channel (alluvial) banks and (consolidated till) bluffs, and dramatically increased sediment supply. Here we leverage multiple decades of aerial photos, repeat lidar surveys, Structure from Motion photogrammetry and sediment gaging to examine past, and predict future, changes in channel width. We use empirical observations and a simple model to examine whether semi-alluvial channels tend toward a single, or multiple, equilibrium channel width(s). Preliminary results suggest that under stationary hydrologic conditions (1930s - 1970s) channel width was relatively consistent among reaches underlain by alluvium versus consolidated till. Since the late 1970s the study area has undergone profound hydrologic changes, with geomorphically-active flows nearly doubling in magnitude. Alluvial reaches widened relatively quickly in response to the increase in flows, whereas reaches underlain by till have not seen the same amount of widening. Aerial lidar-based geomorphic change detection between 2005 - 2012 records channel width changes in response to an extreme flood in 2010 and corroborates the notion that alluvial reaches respond more quickly than do till counterparts. We use a bathymetric map and morphodynamic modeling to explore whether the rates of adjustment simply differ or whether differences in bank strength change the processes governing channel width adjustment.

The influence of flood frequency, riparian vegetation and threshold on long-term river transport capacity

NASA Astrophysics Data System (ADS)

Croissant, Thomas; Lague, Dimitri; Davy, Philippe

2016-04-01

Climate fluctuations at geological timescales control the capacity of rivers to transport sediment with consequences on geochemical cycles, sedimentary basins dynamics and sedimentation/tectonics interactions. While the impact of differential friction generated by riparian vegetation has been studied for individual flood events, its impact on the long-term sediment transport capacity of rivers, modulated by the frequency of floods remains unknown. Here, we investigate this effect on a simplified river-floodplain configuration obeying observed hydraulic scaling laws. We numerically integrate the full-frequency magnitude distribution of discharge events and its impact on the transport capacity of bedload and suspended material for various level of vegetation-linked differential friction. We demonstrate that riparian vegetation by acting as a virtual confinement of the flow i) increases significantly the instantaneous transport capacity of the river independently of the transport mode and ii) increases the long term bedload transport rates as a function of discharge variability. Our results expose the dominance of flood frequency rather than riparian vegetation on the long term sediment transport capacity. Therefore, flood frequency has to be considered when evaluating long-term bedload transport capacity while floodplain vegetation is important only in high discharge variability regimes. By comparing the transport capacity of unconfined alluvial rivers and confined bedrock gorges, we demonstrate that the latter always presents the highest long term transport capacity at equivalent width and slope. The loss of confinement at the transition between bedrock and alluvial river must be compensated by a widening or a steepening of the alluvial channel to avoid infinite storage. Because steepening is never observed in natural system, we compute the alluvial widening factor value that varies between 3 to 11 times the width of the bedrock channel depending on riparian vegetation and discharge variability. This result is well supported by measurements made in natural river systems in different worldwide locations (Taiwan, Himalayas and New Zealand). Although bank cohesion is often invoked to as a property that sets alluvial river width, we propose unconfinement as another important control factor.

Geomorphic analysis of large alluvial rivers

NASA Astrophysics Data System (ADS)

Thorne, Colin R.

2002-05-01

Geomorphic analysis of a large river presents particular challenges and requires a systematic and organised approach because of the spatial scale and system complexity involved. This paper presents a framework and blueprint for geomorphic studies of large rivers developed in the course of basic, strategic and project-related investigations of a number of large rivers. The framework demonstrates the need to begin geomorphic studies early in the pre-feasibility stage of a river project and carry them through to implementation and post-project appraisal. The blueprint breaks down the multi-layered and multi-scaled complexity of a comprehensive geomorphic study into a number of well-defined and semi-independent topics, each of which can be performed separately to produce a clearly defined, deliverable product. Geomorphology increasingly plays a central role in multi-disciplinary river research and the importance of effective quality assurance makes it essential that audit trails and quality checks are hard-wired into study design. The structured approach presented here provides output products and production trails that can be rigorously audited, ensuring that the results of a geomorphic study can stand up to the closest scrutiny.

Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma

USGS Publications Warehouse

Adams, G.P.; Runkle, Donna; Rea, Alan; Cederstrand, J.R.

1997-01-01

ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries, maps of hydraulic conductivity, recharge, and ground-water level elevation contours for the alluvial and terrace deposits along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma. Ground water in 1,305 square miles of Quaternary-age alluvial and terrace deposits along the the Cimarron River from Freedom to Guthrie is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. Alluvial and terrace deposits are composed of interfingering lenses of clay, sandy clay, and cross-bedded poorly sorted sand and gravel. The aquifer is composed of hydraulically connected alluvial and terrace deposits that unconformably overlie the Permian-age Formations. The aquifer boundaries are from a ground-water modeling report on the alluvial and terrace aquifer along the Cimarron River from Freedom to Guthrie in northwestern Oklahoma and published digital surficial geology data sets. The aquifer boundary data set was created from digital geologic data sets from maps published at a scale of 1:250,000. The hydraulic conductivity values, recharge rates, and ground-water level elevation contours are from the ground-water modeling report. Water-level elevation contours were digitized from a map at a scale of 1:250,000. The maps were published at a scale of 1:900,000. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

Visualizing Sungai Batu Ancient River, Lembah Bujang Archeology Site, Kedah – Malaysia using 3-D Resistivity Imaging

NASA Astrophysics Data System (ADS)

Yusoh, R.; Saad, R.; Saidin, M.; Muhammad, S. B.; Anda, S. T.; Ashraf, M. A. M.; Hazreek, Z. A. M.

2018-04-01

Sungai Batu at lembah bujang has become an interest spot for archeologist since it was discover as earliest entrepot in history of Malaysia. It is believe that there was a large lost river near the ancient jetty remain. Ground resistivity method was implement with large coverage area to locate the ancient river direction. Eleven ground resistivity survey line was carry out using SAS4000 equipment and wenner-schlumberger array was applied for measurement. Ground resistivity method was used to detect the alluvial deposit made by the ancient river deposition. The ground resistivity data were produce in 2D image and presented in 3D contour map for various selected depth by using Rockwork 15 and Surfer 8 software to visualize the alluvial deposits area. The results from the survey has found the appearance of sedimentation formation due to low resistivity value (0 – 330 ohm.m) was found near the existing river. However, the width of alluvial deposition was 1400 m which too wide for river width unless it was a deposition happen form age to age by movement of river meander. It’s conclude that the river was still at the same direction and its direction was change due to sediment dumping factor waking it shifting to the east.

Stratigraphy of Aeolis Dorsa, Mars: Stratigraphic context of the great river deposits

NASA Astrophysics Data System (ADS)

Kite, Edwin S.; Howard, Alan D.; Lucas, Antoine S.; Armstrong, John C.; Aharonson, Oded; Lamb, Michael P.

2015-06-01

Unraveling the stratigraphic record is the key to understanding ancient climate and past climate changes on Mars (Grotzinger, J. et al. [2011]. Astrobiology 11, 77-87). Stratigraphic records of river deposits hold particular promise because rain or snowmelt must exceed infiltration plus evaporation to allow sediment transport by rivers. Therefore, river deposits when placed in stratigraphic order could constrain the number, magnitudes, and durations of the wettest (and presumably most habitable) climates in Mars history. We use crosscutting relationships to establish the stratigraphic context of river and alluvial-fan deposits in the Aeolis Dorsa sedimentary basin, 10°E of Gale crater. At Aeolis Dorsa, wind erosion has exhumed a stratigraphic section of sedimentary rocks consisting of at least four unconformity-bounded rock packages, recording three or more distinct episodes of surface runoff. Early deposits (>700 m thick) are embayed by river deposits (>400 m thick), which are in turn unconformably draped by fan-shaped deposits (<100 m thick) which we interpret as alluvial fans. Yardang-forming layered deposits (>900 m thick) unconformably drape all previous deposits. River deposits embay a dissected landscape formed of sedimentary rock. The river deposits are eroding out of at least two distinguishable units. There is evidence for pulses of erosion during the interval of river deposition. The total interval spanned by river deposits is >(1 × 106-2 × 107) yr, and this is extended if we include alluvial-fan deposits. Alluvial-fan deposits unconformably postdate thrust faults which crosscut the river deposits. This relationship suggests a relatively dry interval of >4 × 107 yr after the river deposits formed and before the fan-shaped deposits formed, based on probability arguments. Yardang-forming layered deposits unconformably postdate all of the earlier deposits. They contain rhythmite and their induration suggests a damp or wet (near-) surface environment. The time gap between the end of river deposition and the onset of yardang-forming layered deposits is constrained to >1 × 108 yr by the high density of impact craters embedded at the unconformity. The time gap between the end of alluvial-fan deposition and the onset of yardang-forming layered deposits was at least long enough for wind-induced saltation abrasion to erode 20-30 m into the alluvial-fan deposits. We correlate the yardang-forming layered deposits to the upper layers of Gale crater's mound (Mt. Sharp/Aeolis Mons), and the fan-shaped deposits to Peace Vallis fan in Gale crater. Alternations between periods of low mean obliquity and periods of high mean obliquity may have modulated erosion-deposition cycling in Aeolis. This is consistent with the results from an ensemble of simulations of Solar System orbital evolution and the resulting history of the obliquity of Mars. 57 of our 61 simulations produce one or more intervals of continuously low mean Mars obliquity that are long enough to match our Aeolis Dorsa unconformity data.

Hydrologic influences on soil properties along ephemeral rivers in the Namib Desert

USGS Publications Warehouse

Jacobson, P.J.; Jacobson, K.M.; Angermeier, P.L.; Cherry, D.S.

2000-01-01

Soils were examined along three ephemeral rivers in the Namib Desert to assess the influence of their hydrologic characteristics on soil properties. Soils consisted of layers of fluvially deposited, organic-rich silts, interstratified with fluvial and aeolian sands. The most significant influence of the ephemeral hydrologic regime upon soils was related to the downstream alluviation associated with hydrologic decay. This alluviation increased the silt proportion of soils in the lower reaches of the rivers. Organic carbon, nitrogen and phosphorous were correlated with silt content, and silt deposition patterns influenced patterns of moisture availability and plant rooting, creating and maintaining micro-habitats for various organisms. Localized salinization occurred in association with wetland sites and soluble salt content tended to increase downstream. Because of the covariance between silt and macronutrients, and the influence of silt upon moisture availability and habitat suitability, alluviation patterns associated with the hydrologic regime strongly influence the structure, productivity, and spatial distribution of biotic communities in ephemeral river ecosystems. (C) 2000 Academic Press.

Flow characteristics and longitudinal sorting patterns associated with stable alluvial-bedrock and bedrock-alluvial transitions

NASA Astrophysics Data System (ADS)

Jafarinik, S.; Viparelli, E.

2017-12-01

Recent research recognized the existence of bedrock channels in low-slope rivers, but little is known about the morphodynamics of bedrock-alluvial and alluvial-bedrock transitions in these systems. Bedrock-alluvial and alluvial-bedrock transitions are fluvial features separating bedrock and alluvial reaches. In the bedrock reach the river bed is partially covered with alluvium. An increase in sediment supply to an alluvial reach results in channel bed aggradation. An increase in sediment supply to a bedrock reach, on the other hand, results in a reduction of the exposed bedrock. Mathematical modeling of the alluvial morphodynamics of bedrock reaches reveals that these transitions can characterize transient or equilibrium conditions. Model results show that the magnitude of the alluvial equilibrium slope and the depth of the bedrock surface relative to the downstream water surface base level have a primary control on the equilibrium conditions. Further, numerical results show that when a stable bedrock-alluvial transition forms, the bed material transport capacity in bedrock reach decreases in the flow direction. On the contrary, when a stable alluvial-bedrock transition forms the bed material transport capacity in the bedrock reach increases in the flow direction. These spatial changes in bed material transport capacity are associated with spatial changes in alluvial cover and flow hydrodynamics. Here we present a one-dimensional formulation of alluvial morphodynamics that accounts for the non-uniformity of the bed material and for the spatial change in flow resistances associated with the spatial and temporal changes in flow hydrodynamics of the bedrock reaches. This change in flow resistances can be associated with 1) changes in skin friction due to longitudinal changes in the grain size distribution of the bed surface, and/or 2) changes in bedform geometry associated with the interaction between the alluvial cover and the underlying bedrock. The model has been validated against laboratory experiments with stable alluvial-bedrock transitions and is applied to describe the spatial changes in flow characteristics and sediment sorting patterns upstream of a stable bedrock-alluvial transition.

Hydrocarbon Status of Alluvial Soils in the Istra Morphostructural Node (Moscow Oblast)

NASA Astrophysics Data System (ADS)

Pikovskiy, Yu. I.; Gennadiev, A. N.; Kovach, R. G.; Khlynina, N. I.; Khlynina, A. V.

2017-12-01

The effect of the current block structure of the earth's crust and its most active sites (morphostructural nodes) on the natural hydrocarbon status of alluvial soils has been considered. Studies have been performed in the Istra district of Moscow oblast within the Istra morphostructural node. The node represents an area of increased geodynamic activity of the earth's crust located at the convergence or intersection of block boundaries: mobile linear zones following large river valleys with alluvial soils. Soil cover mainly consists of alluvial humic-gley soils (Eutric Gleyic Fluvisols) of different depths and alluvial mucky-gley soils (Eutric Gleyic Histic Fluvisols). Some soils manifest stratification. Two factors forming the hydrocarbon status of soils are considered: soil processes and the effect of geodynamic activity, which is manifested within the morphostructural node. The contents of bitumoids and retained methane and butanes in alluvial soils appreciably increase at the entry of river valley into the node. The occurrence frequency of 5-6-ring polycyclic aromatic hydrocarbons (perylene and benzo[ghi]perylene) in mineral horizons increases. It has been concluded that alluvial soils within the Istra morphostructural node are characterized by the biogeochemical type of hydrocarbon status with signs of emanation type at sites with the highest geodynamic activity.

Effects of alluvial knickpoint migration on floodplain ecology and geomorphology

NASA Astrophysics Data System (ADS)

Larsen, Annegret; May, Jan-Hendrick

2016-04-01

Alluvial knickpoints are well described as erosional mechanism within discontinuous ephemeral streams in the semi-arid SW USA. However, alluvial knickpoints occur globally in a wide range of settings and of climate zones, including temperate SE Australia, subtropical Africa, and tropical Australia. Much attention has been given in the scientific literature to the trigger mechanisms of alluvial knickpoints, which can be summarized as: i) threshold phenomena, ii) climate variability and iii) land-use change, or to a combination of these factors. Recently, studies have focused on the timescale of alluvial knickpoint retreat, and the processes, mechanisms and feedbacks with ecology, geomorphology and hydrology. In this study, we compile data from a global literature review with a case study on a tropical river system in Australia affected by re-occurring, fast migrating (140 myr-1) alluvial knickpoint. We highlight the importance of potential water table declines due to channel incision following knickpoint migration, which in turn leads to the destabilization of river banks, and a shift in floodplain vegetation and fire incursion. We hypothesize that the observed feedbacks might also help to understand the broader impacts of alluvial knickpoint migration in other regions, and might explain the drastic effects of knickpoint migration on land cover and land-use in semi-arid areas.

Regional water quality patterns in an alluvial aquifer: direct and indirect influences of rivers.

PubMed

Baillieux, A; Campisi, D; Jammet, N; Bucher, S; Hunkeler, D

2014-11-15

The influence of rivers on the groundwater quality in alluvial aquifers can be twofold: direct and indirect. Rivers can have a direct influence via recharge and an indirect one by controlling the distribution of fine-grained, organic-carbon rich flood deposits that induce reducing conditions. These direct and indirect influences were quantified for a large alluvial aquifer on the Swiss Plateau (50km(2)) in interaction with an Alpine river using nitrate as an example. The hydrochemistry and stable isotope composition of water were characterized using a network of 115 piezometers and pumping stations covering the entire aquifer. Aquifer properties, land use and recharge zones were evaluated as well. This information provided detailed insight into the factors that control the spatial variability of groundwater quality. Three main factors were identified: (1) diffuse agricultural pollution sources; (2) dilution processes resulting from river water infiltrations, revealed by the δ(18)OH2O and δ(2)HH2O contents of groundwater; and (3) denitrification processes, controlled by the spatial variability of flood deposits governed by fluvial depositional processes. It was possible to quantify the dependence of the nitrate concentration on these three factors at any sampling point of the aquifer using an end-member mixing model, where the average nitrate concentration in recharge from the agricultural area was evaluated at 52mg/L, and the nitrate concentration of infiltrating river at approximately 6mg/L. The study shows the importance of considering the indirect and direct impacts of rivers on alluvial aquifers and provides a methodological framework to evaluate aquifer scale water quality patterns. Copyright © 2014 Elsevier B.V. All rights reserved.

Interannual kinetics (2010-2013) of large wood in a river corridor exposed to a 50-year flood event and fluvial ice dynamics

NASA Astrophysics Data System (ADS)

Boivin, Maxime; Buffin-Bélanger, Thomas; Piégay, Hervé

2017-02-01

Semi-alluvial rivers of the Gaspé Peninsula, Québec, are prone to produce and transport vast quantities of large wood (LW). The high rate of lateral erosion owing to high energy flows and noncohesive banks is the main process leading to the recruitment of large wood, which in turn initiates complex patterns of wood accumulation and reentrainment within the active channel. The delta of the Saint-Jean River (SJR) has accumulated large annual wood fluxes since 1960 that culminated in a wood raft of > 3-km in length in 2014. To document the kinetics of large wood on the main channel of SJR, four annual surveys were carried out from 2010 to 2013 to locate and describe > 1000 large wood jams (LWJ) and 2000 large wood individuals (LWI) along a 60-km river section. Airborne and ground photo/video images were used to estimate the wood volume introduced by lateral erosion and to identify local geomorphic conditions that control wood mobility and deposits. Video camera analysis allowed the examination of transport rates from three hydrometeorological events for specific river sections. Results indicate that the volume of LW recruited between 2010 and 2013 represents 57% of the total LW production over the 2004-2013 period. Volumes of wood deposited along the 60-km section were four times higher in 2013 than in 2010. Increases in wood amount occurred mainly in upper alluvial sections of the river, whereas decreases were observed in the semi-alluvial middle sections. Observations suggest that the 50-year flood event of 2010 produced large amounts of LW that were only partly exported out of the basin so that a significant amount was still available for subsequent floods. Large wood storage continued after this flood until a similar flood or an ice-breakup event could remobilise these LW accumulations into the river corridor. Ice-jam floods transport large amounts of wood during events with fairly low flow but do not contribute significantly to recruitment rates (ca. 10 to 30% early). It is fairly probable that the wood export peak observed in 2012 at the river mouth, where no flood occurred and which is similar to the 1-in 10-year flood of 2010, is mainly linked to such ice-break events that occurred in March 2012.

Outlook for Mississippi Alluvial Valley forests: a subregional report from the Southern Forest Futures Project

Treesearch

Emile S. Gardiner

2015-01-01

The Mississippi Alluvial Valley, which can be broadly subdivided into the Holocene Deposits section and the Deltaic Plain section, is a 24.9-million-acre area generally approximating the alluvial floodplain and delta of the lower Mississippi River. Its robust agricultural economy is maintained by a largely rural population, and recreational resources draw high...

Coal depositional models in some Tertiary and Cretaceous coal fields in the U.S. Western Interior

USGS Publications Warehouse

Flores, R.M.

1979-01-01

Detailed stratigraphic and sedimentological studies of the Tertiary Tongue River Member of the Fort Union Formation in the Powder River Basin, Wyoming, and the Cretaceous Blackhawk Formation and Star Point Sandstone in the Wasatch Plateau, Utah, indicate that the depositional environments of coal played a major role in controlling coal thickness, lateral continuity, potential minability, and type of floor and roof rocks. The potentially minable, thick coal beds of the Tongue River Member were primarily formed in long-lived floodbasin backswamps of upper alluvial plain environment. Avulsion of meandering fluvial channels contributed to the erratic lateral extent of coals in this environment. Laterally extensive coals formed in floodbasin backswamps of a lower alluvial plain environment; however, interruption by overbank and crevasse-splay sedimentation produced highly split and merging coal beds. Lacustrine sedimentation common to the lower alluvial plain, similar to the lake-covered lower alluvial valley of the Atchafalaya River Basin, is related to a high-constructive delta. In contrast to these alluvial coals are the deltaic coal deposits of the Blackhawk Formation. The formation consists of three coal populations: upper delta plain, lower delta plain, and 'back-barrier'. Coals of the lower delta plain are thick and laterally extensive, in contrast to those of the upper delta plain and 'back-barrier', which contain abundant, very thin and laterally discontinuous carbonaceous shale partings. The reworking of the delta-front sediments of the Star Point Sandstone suggests that the Blackhawk-Star Point delta was a high-destructive system. ?? 1979.

Reconnaissance of ground-water quality in the Papio-Missouri River Natural Resources District, eastern Nebraska, July through September 1992

USGS Publications Warehouse

Verstraeten, Ingrid M.; Ellis, M.J.

1995-01-01

A reconnaissance of ground-water quality was conducted in the Papio-Missouri River Natural Resources District of eastern Nebraska. Sixty-one irrigation, municipal, domestic, and industrial wells completed in the principal aquifers--the unconfined Elkhorn, Missouri, and Platte River Valley alluvial aquifers, the upland area alluvial aquifers, and the Dakota aquifer--were selected for water-quality sampling during July, August, and September 1992. Analyses of water samples from the wells included determination of dissolved nitrate as nitrogen and triazine and acetanilide herbicides. Waterquality analyses of a subset of 42 water samples included dissolved solids, major ions, metals, trace elements, and radionuclides. Concentrations of dissolved nitrate as nitrogen in water samples from 2 of 13 wells completed in the upland area alluvial aquifers exceeded the U.S. Environmental Protection Agency Maximum Contaminant Level for drinking water of 10 milligrams per liter. Thirty-nine percent of the dissolved nitrate-as-nitrogen concentrations were less than the detection level of 0.05 milligram per liter. The largest median dissolved nitrate-as-nitrogen concentrations were in water from the upland area alluvial aquifers and the Dakota aquifer. Water from all principal aquifers, except the Dakota aquifer, had detectable concentrations of herbicides. Herbicides detected included alachlor (1 detection), atrazine (13 detections), cyanazine (5 detections), deisopropylatrazine (6 detections), deethylatrazine (9 detections), metolachlor (6 detections), metribuzin (1 detection), prometon (6 detections), and simazine (2 detections). Herbicide concentrations did not exceed U.S. Environmental Protection Agency Maximum Contaminant Levels for drinking water. In areas where the hydraulic gradient favors loss of surface water to ground water, the detection of herbicides in water from wells along the banks of the Platte River indicates that the river could act as a line source of herbicides. Water from the alluvial and bedrock aquifers generally was a calcium bicarbonate type and was hard. Two of nine water samples collected from the Dakota aquifer contained calcium sulfate type water. Results of analyses of 42 groundwater samples for major ions, metals, trace elements, and radionuclide constituents indicated that statistically at least one principal aquifer had significant differences in its water chemistry. In general, the water chemistry of the Dakota aquifer was similar to the water chemistry of the upland area alluvial aquifers in areas where there was a hydraulic connection. The water from the Dakota aquifer had large dissolved-solids, calcium, sulfate, chloride, iron, lithium, manganese, and strontium concentrations in areas where the aquifer is thought not to be in hydraulic connection with the Missouri River Valley and upland area alluvial aquifers. Ground-water quality in the Papio-MissouriRiver Natural Resources District is generally suitable for most uses. However, the numerous occurrences of herbicides in water of the Elkhorn and Platte River Valley alluvial aquifers, especially near the Platte River, are of concern because U.S. Environmental Protection Agency Maximum Contaminant Levels could be exceeded. Concentrations in three of nine water samples collected from wells completed in the Dakota aquifer exceeded the U.S. Environmental Protection Agency Maximum Contaminant Levels or Secondary Maximum Contaminant Levels for gross alpha activity, radon-222 activity, dissolved solids, sulfate, or iron. Also of concern are the exceedances of the U.S Environmental Protection Agency proposed Maximum Contaminant Level for radon-222 activity.

Exploring Controls on Sinuousity, Terraces and River Capture in the Upper Dajia River, Taiwan

NASA Astrophysics Data System (ADS)

Belliveau, L. C.; Ouimet, W. B.; Chan, Y. C.; Byrne, T. B.

2015-12-01

Taiwan is one of the most tectonically active regions in the world and is prone to landslides due to steep topography, large earthquakes and frequent typhoons. Landslides often affect and alter the river valleys beneath them, producing knickpoints on longitudinal river profiles, segmenting valleys into mixed bedrock-alluvial rivers and affecting river incision for tens to thousands of years. This study investigates the origin and evolution of complex channel morphologies, terraces and river capture along a 20km stretch of the Upper Da-Jia River in the Heping area of Taiwan. Through GIS analysis and field studies, we explore controls on river channel sinuousity, terrace development and river capture in relation to tectonic and climatic forcing, rock erodibility and landslides. High channel sinuousity is proposed as the result of a coupling between bank erosion and landslides. We discuss three types of landslide-induced meanders and increased sinuousity: (a) depositional-push meanders, (b) failure-zone erosional meanders, and (c) complex-erosional meanders. We also investigate spatial variation in channel morphology (slope, width) and the distribution and heights of river terraces within the Upper Da-Jia watershed associated with periods of widespread valley filling from landslide activity. Examples of river capture provide further evidence of the dynamic interactions between river incision, landslides and associated changes in channel morphology and terrace development within steep rapidly uplift, eroding and evolving mountain belts.

Geohydrology of the alluvial and terrace deposits of the North Canadian River from Oklahoma City to Eufaula Lake, central Oklahoma

USGS Publications Warehouse

Havens, J.S.

1989-01-01

This investigation was undertaken to describe the geohydrology of the alluvial and terrace deposits along the North Canadian River between Lake Overholser and Eufaula Lake, an area of about 1,835 square miles, and to determine the maximum annual yield of ground water. A 1982 water-level map of the alluvial and terrace aquifer was prepared using field data and published records. Data from test holes and other data from the files of the U.S. Geological Survey and the Oklahoma Water Resources Board were used to establish the approximate thickness of the alluvial and terrace deposits. The North Canadian River from Lake Overholser, near Oklahoma City, to Eufaula Lake is paralleled by a 2- to 3-mile wide band of alluvium. Scattered terrace deposits on either side of the alluvium reach an extreme width of 8 miles. Rocks of Permian age bound the alluvial and terrace deposits from the west to the midpoint of the study area; Pennsylvanian rocks bound the alluvial and terrace deposits from that point eastward. Three major aquifers are present in the study area: the alluvial and terrace aquifer, consisting of alluvium and terrace deposits of Quaternary age in a narrow band on either side of the North Canadian River; the Garber-Wellington aquifer of Permian age, consisting of an upper unconfined zone and a lower confined zone separated by relatively impermeable shales; and the Ada-Vamoosa aquifer of Pennsylvanian age. At locations were the alluvial and terrace aquifer overlies either of the other aquifers, there is hydraulic continuity between the alluvial and terrace aquifer and the other aquifers, and water levels are the same. Most large-scale municipal and industrial pumping from the Garber-Wellington aquifer is from the lower zone and has little discernible effect upon the alluvial and terrace aquifer. The total estimated base flow of the North Canadian River for the studied reach is 264 cubic feet per second. Evapotranspiration from the basin in August is about 60 cubic feet per second for the North Canadian River from Lake Overholser to a measuring station above Eufaula Lake. Estimated recharge rates to the alluvial and terrace aquifer in the basin range from 1.7 inches at the west edge of the study area to 7.0 inches at the east edge. Total permitted withdrawal from the aquifer, according to records of the Oklahoma Water Resources Board, ranged from 2,107 acre-feet per year in 1942 to about 21,415 acre-feet per year in 1982. Simulations of the alluvial and terrace aquifer from Lake Overholser to Eufaula Lake were made using a finite-difference model developed by McDonald and Harbaugh (1984). The area of the aquifers was subdivided into a finite-difference grid having 30 rows and 57 columns with cells measuring 1 mile in the north-south direction and 2 miles in the east-west direction. The model was calibrated in two steps: A steady-state calibration simulated head distribution prior to extensive pumping of the aquifer in 1942, and a transient calibration simulated head distribution after extensive pumpage. The final horizontal hydraulic conductivity used for the alluvial and terrace aquifer was 0.0036 feet per second (310 feet per day) at all locations. The recharge rate for the alluvial and terrace aquifer ranged from 1.7 inch per year in the west to 7.0 inches per year in the east, and averaged about 3.3 inches per year. A specific yield of 15 percent was used for the transient simulation. Permitted pumpage for 1942 through 1982 was used in the digital model to estimate the annual volume of water in storage in the alluvial and terrace aquifer for the years for this time period. The 1982 permitted pumpage rates were used for projections for 1983 to 2020. The estimated volume of water in storage was 1,940,000 acre-feet in 1982. Because the estimated recharge rate is equal to the allowed pumpage rate in 1982, the projected volume of water in storage in both 1993 and 2020 was 1,890,000 acre-feet.

Simulation of ground-water flow, contributing recharge areas, and ground-water travel time in the Missouri River alluvial aquifer near Ft. Leavenworth, Kansas

USGS Publications Warehouse

Kelly, Brian P.

2004-01-01

The Missouri River alluvial aquifer near Ft. Leavenworth, Kansas, supplies all or part of the drinking water for Ft. Leavenworth; Leavenworth, Kansas; Weston, Missouri; and cooling water for the Kansas City Power and Light, Iatan Power Plant. Ground water at three sites within the alluvial aquifer near the Ft. Leavenworth well field is contaminated with trace metals and organic compounds and concerns have been raised about the potential contamination of drinking-water supplies. In 2001, the U.S. Geological Survey, U.S. Army Corps of Engineers, and the U.S. Army began a study of ground-water flow in the Missouri River alluvial aquifer near Ft. Leavenworth. Hydrogeologic data from 173 locations in the study area was used to construct a ground-water flow model (MODFLOW-2000) and particle-tracking program (MODPATH) to determine the direction and travel time of ground-water flow and contributing recharge areas for water-supply well fields within the alluvial aquifer. The modeled area is 28.6 kilometers by 32.6 kilometers and contains the entire study area. The model uses a uniform grid size of 100 meters by 100 meters and contains 372,944 cells in 4 layers, 286 columns, and 326 rows. The model represents the alluvial aquifer using four layers of variable thickness with no intervening confining layers. The model was calibrated to both quasi-steady-state and transient hydraulic head data collected during the study and ground-water flow was simulated for five well-pumping/river-stage scenarios. The model accuracy was calculated using the root mean square error between actual measurements of hydraulic head and model generated hydraulic head at the end of each model run. The accepted error for the model calibrations were below the maximum measurement errors. The error for the quasi-steady-state calibration was 0.82 meter; for the transient calibration it was 0.33 meter. The shape, size, and ground-water travel time within the contributing recharge area for each well or well field is affected by changes in river stage and pumping rates and by the location of the well or well field with respect to the major rivers, alluvial valley walls, and other pumping wells. The shapes of the simulated contributing recharge areas for the well fields in the study area are elongated in the upstream direction for all well-pumping/river-stage scenarios. The capture of ground water by the pumping wells as it moved downgradient toward the Missouri River caused the long up-valley extent of the contributing recharge areas. Recharge to the Iatan and Weston well fields primarily is from precipitation and surface runoff from the surrounding uplands because the contributing recharge area does not intersect the Missouri River for any well-pumping/river-stage scenarios. Recharge to the Leavenworth and Ft. Leavenworth well fields is from precipitation, surface runoff from the surrounding uplands, and the Missouri River because the contributing recharge area intersects these boundaries for all well-pumping/river-stage scenarios. Particle tracking analysis indicated ground water from the three contaminated sites was captured by the Ft. Leavenworth well field for all well-pumping/river-stage scenarios. Ground-water travel times to the Ft. Leavenworth well field for average well-pumping/river-stage scenario ranged from about 33 years for the closest contamination site to about 71 years for the farthest contamination site. Ground-water flow was induced below the Missouri River by the Ft. Leavenworth and Leavenworth well fields for all well-pumping/river-stage scenarios.

The Importance of Bank Storage in Supplying Baseflow to Rivers Flowing Through Compartmentalized, Alluvial Aquifers

NASA Astrophysics Data System (ADS)

Rhodes, Kimberly A.; Proffitt, Tiffany; Rowley, Taylor; Knappett, Peter S. K.; Montiel, Daniel; Dimova, Natasha; Tebo, Daniel; Miller, Gretchen R.

2017-12-01

As water grows scarcer in semiarid and arid regions around the world, new tools are needed to quantify fluxes of water and chemicals between aquifers and rivers. In this study, we quantify the volumetric flux of subsurface water to a 24 km reach of the Brazos River, a lowland river that meanders through the Brazos River Alluvium Aquifer (BRAA), with 8 months of high-frequency differential gaging measurements using fixed gaging stations. Subsurface discharge sources were determined using natural tracers and End-Member Mixing Analysis (EMMA). During a 4 month river stage recession following a high stage event, subsurface discharge decreased from 50 m3/s to 0, releasing a total of 1.0 × 108 m3 of water. Subsurface discharge dried up even as the groundwater table at two locations in the BRAA located 300-500 m from the river remained ˜4 m higher than the river stage. Less than 4% of the water discharged from the subsurface during the prolonged recession period resembled the chemical fingerprint of the alluvial aquifer. Instead, the chemistry of this discharged water closely resembled high stage "event" river water. Together, these findings suggest that the river is well connected to rechargeable bank storage reservoirs but disconnected from the broader alluvial aquifer. The average width of discrete bank storage zones on each side of the river, identified with Electrical Resistivity Tomography (ERT), was approximately 1.5 km. In such highly compartmentalized aquifers, groundwater pumping is unlikely to impact the exchange between the river and the alluvium.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Imes, J.L.; Kleeschulte, M.J.

Ground-water-level measurements to support remedial actions were made in 37 piezometers and 19 monitoring wells during a 19-month period to assess the potential for ground-water flow from an abandoned quarry to the nearby St. Charles County well field, which withdraws water from the base of the alluvial aquifer. From 1957 to 1966, low-level radioactive waste products from the Weldon Spring chemical plant were placed in the quarry a few hundred feet north of the Missouri River alluvial plain. Uranium-based contaminants subsequently were detected in alluvial ground water south of the quarry. During all but flood conditions, lateral ground-water flow inmore » the bedrock from the quarry, as interpreted from water-table maps, generally is southwest toward Little Femme Osage Creek or south into the alluvial aquifer. After entering the alluvial aquifer, the ground water flows southeast to east toward a ground-water depression presumably produced by pumping at the St. Charles County well field. The depression position varies depending on the Missouri River stage and probably the number and location of active wells in the St. Charles County well field.« less

Fluvial sedimentary styles and associated depositional environments in the buntsandstein west of river rhine in saar area and pfalz (F.R. Germany) and vosges (France)

NASA Astrophysics Data System (ADS)

Dachroth, Wolfgang

The Buntsandstein west of river Rhine in Saar area, Pfalz and Vosges consists of three fluvial magnacycles which are characterized by different associated non-alluvial environments. The stratigraphic sequence is divided by several unconformities reflecting tectonic movements which were connected with periods of extension of the depositional area. Two major phases and two minor events are recognized by the evaluation of the Pfalz unconformity and the Lothringen unconformity, and the Leuter unconformity and the Saar unconformity, respectively. The Lower Buntsandstein (including Zechstein) compries the first magnacycle and is built up of alluvial-fan deposits, fluvial braidplain sediments and marine to lagoonal deposits. Some aeolian sands as well as several palaeosols are also present. The palaeolandscape consists of alluvial fans seaming the margin of the basin and fluvial braidplains reaching from the toes of the fan belt to the centre of the depositional area which is occupied by a lagoonal sea that partially evolves into a playa-lake with progressive refreshment. The Middle Buntsandstein comprises the second magnacycle and is composed of an alternation of aeolian Dünnschichten and fluvial Felsbänke. The third facies are alluvial-fan deposits of palaeogeographically restricted distribution along the margins of the basin. The aeolian Dünnschichten originate in the marginal parts of chott-type depressions (in comparison with the recent Chott Djerid in Tunesia) where rising ground water moistens the dry sediments that are laid down on the playa floor and thus allows their enhanced preservation. In dry periods, wind-blown sand is spread out as plane sheets or as migrating wind ripple trains, or accumulates to barchanoid-type dunes that advance across the flat. Depending on supply of sand, all stages of transition between dune fields with only narrow interdune corridors between the ridges and interdune playas with isolated widely-spaced dunes are developed. The individual sand storms operating in the erg are recorded in a mm-scale graded grain-size lamination. The desert-type setting is divided into depositional sand ergs where aeolian bedforms migrate, and deflationary gravel serirs where pebbly fluvial sediments are winnowed, resulting in concentration of the gravel to residual lags and in abundant grinding of clasts to ventifacts. During time of flooding of the chotts by atmospheric precipitation, fluvial incursions or rising ground water level, lacustrine playa deposits settle out in shallow stagnant water. The fluvial Felsbänke originate in wadi-type braided river systems intersecting the erg and serir zones and often redepositing aeolian sand which is derived from undercutting during abandonment and displacement of the watercourses. The stream complexes are partially fed at their proximal ends by runoff from local alluvial fans which are aligned along parts of the margins of the basin. The Upper Buntsandstein comprises the third magnacycle which is split into three megacycles that in turn are divided into several phases. A change from generally arid to primarily semi-arid climate along with tectonical up-lift in the source area results in extinction of aeolian deposition and gives rise to formation of Violette Horizonte calcrete palaeosols which are widespread throughout the Upper Buntsandstein, if their origin was not inhibited by the dynamics of the fluvial systems. The palaeosols occur in different evolutionary stages and are mainly characterized by the typical blue-violet colour, presence of root tubes, carbonate nodules and carbonate crusts, destratification and polyedric jointing. The fluvial fining-upwards cyclothems are formed in braided river systems which partially pass into meandering stream complexes. At the top of the Upper Buntsandstein, the alluvial inland plain is converted into a delta complex in the coastal plain along the approaching sea, and with a sequence of alternating progradation and recession events, the Muschelkalk transgression finally inundates the continental setting.

Ground-Water Resource Assessment in the Rio Grande de Manati Alluvial Plain, Rio Arriba Saliente Area, Puerto Rico

USGS Publications Warehouse

Torres-Gonzalez, Sigfredo; Gómez-Gómez, Fernando; Warne, Andrew G.

2002-01-01

The alluvial aquifer within a 160-acre area of the Rio Grande de Manati alluvial plain was investigated to evaluate its potential as a water-supply source for the Barrios Rio Arriba Saliente and Pugnado Afuera, municipio of Manati, Puerto Rico. Analysis of well boring samples and the results of electric resistivity surveys indicate that the average thickness of the unconsolidated alluvial deposits in the study area is about 100 to 110 feet. The alluvium is a mixture of sand and gravel, which generally has a porosity of 0.2 to 0.35. Short-duration pump tests in small-diameter piezometers indicate that the alluvial aquifer has a hydraulic conductivity of about 200 feet per day and a transmissivity of about 7,900 feet squared per day. Analyses of water levels in piezometers, combined with stage measurements at a series of surveyed reference points along the Rio Grande de Manati channel, indicate that the water-table gradient in the alluvial aquifer is about 0.001, and that ground-water flow is generally from south to north, in the general direction of river flow. The water-table data indicate that the Rio Grande de Manati is the principal source of ground-water recharge to the alluvial aquifer in the study area. Because base flow for the Rio Grande de Manati is usually greater than 44 cubic feet per second, a continuous withdrawal rate of 0.5 to 1.0 cubic foot per second (225 to 450 gallons per minute) from a production well is possible. Chemical analysis of a ground-water sample indicates that the alluvial aquifer water meets U.S. Environmental Protection Agency secondary standards for selected constituents. Bacteriological analysis of ground-water samples indicates that the ground water contains little or no fecal coliform or fecal streptococcus bacteria. Although long-term data from upstream of the study area indicate high levels of fecal coliform and fecal streptococcus prior to 1996, bacteriological analyses of Rio Grande de Manati water samples obtained during the present study indicate that fecal coliform and fecal streptococcus concentrations are within the standards for surface water intended for use (or with the potential for use) as a raw source of public water supply in Puerto Rico. If a production well were constructed in the study area, it would be located close to the river channel (within 500 to 800 feet). Pumping from the porous and permeable alluvial aquifer close to the river channel could substantially enhance recharge from the Rio Grande de Manati channel to the aquifer. Enhanced recharge could shorten travel times for ground water in the aquifer, which might not allow sufficient time to attenuate bacteria and viruses. Travel times for bacteria moving from the river channel to a hypothetical production well were estimated using the numerical transport model MODFLOW/MT3DMS with an uncalibrated model of the alluvial aquifer. The model assumes a well pumping at 1 cubic foot per second. The transport of particles from the river to the well is most sensitive to the porosity of the aquifer and the pumping rate of the well. Sensitivity analysis indicates that a decrease in pumpage will increase the time of travel for particles to move from the river to the pumping well. The model indicates that the leading edge of a plume would reach the production well in about 40 days assuming a porosity of 0.20, 60 days assuming a porosity of 0.275, and about 70 days assuming a porosity of 0.35. If the well were moved 50 feet further from the river, the leading edge of the plume would reach the well in about 50 days assuming a porosity of 0.20 and about 70 days assuming a porosity of 0.275. These estimates are considered worse case estimates because no decay rate was included in the simulation, and because the hypothetical well was located in the center of the alluvial plain rather than further eastward, away from the river channel.

Fluvial responses to tectonics and climate change during the Late Weichselian in the eastern part of the Pannonian Basin (Hungary)

NASA Astrophysics Data System (ADS)

Nádor, Annamária; Thamó-Bozsó, Edit; Magyari, Árpád; Babinszki, Edit

2007-11-01

Fine-grained sandy-silty channel-belt and floodplain deposits of the Berettyó-Körös Rivers, a main eastern transverse tributary system of the modern Tisza River in the eastern part of the Pannonian Basin, were deposited during the Late Pleistocene under net subsiding conditions. The palaeo-drainage network pattern of a 2500 km 2 large part of the alluvial plain was reconstructed based on interpretation of airborne photographs and analysis of 18th century topographic maps, which show the natural river patterns that predate the introduction of river regulation schemes. The investigation showed that a large meandering river system, with two main channel belts surrounding a floodbasin, entered the alluvial plain from the northeast, and a braided river entered the alluvial plain from the southeast. Detailed sedimentary logs of seven continuous corings and several sand and clay-pit sections were used to characterize different alluvial units. Optical luminescence dating (OSL) of 25 quartz samples and four 14C datings showed that the sediments are of Late Pleniglacial to Late Glacial age. Transport directions inferred from heavy mineral analyses combined with the OSL ages strongly suggest that the large meandering system represents the palaeo-Tisza River, which supposedly flowed along the northeast-southwest striking Érmellék depression during the Late Pleniglacial. The braided river can be regarded as a precursor to the Fekete and Fehér-Körös Rivers, which entered the alluvial plain from the southeast during the Late Glacial. The interpretation of seismic profiles, field measurements of neotectonic activity, and variations in thickness of sediments along the studied profile revealed that river development was largely controlled by subsidence along the Érmellék depression until 14 to 16 ky, and by uplift of the southeastern part of the catchment area. The studied fluvial successions also document the response of the palaeo-Tisza and Körös system to the climate changes of the Weichselian Late Pleniglacial-Late Glacial period. Much of the sand from the meandering zones was deposited during the Bølling-Allerød and Ságvár-Lascaux interstadials, whereas some dated sand units from the braided zone represent the Older and Younger Dryas. The error ranges of OSL dates, which often exceed the duration of Weichselian substages and subdivisions, prevented an unambiguous correlation of the studied sections with the millennial-scale climate changes of the last 25 ky. Meandering and braided river activity coexisted under different climate conditions, whereas locations of the main channel belts are related to subsidence anomalies. The results of our study thus clearly indicate that tectonics was the primary control on river development.

Influence of bedrock on river hydrodynamics and channel geometry

NASA Astrophysics Data System (ADS)

Rennie, C. D.; Church, M. A.; Venditti, J. G.; Bomhof, J.; Adderley, C.

2013-12-01

We present an acoustic Doppler current profiler (aDcp) survey of a 524 km long reach of Fraser River, British Columbia, Canada, as it passes through the Fraser Canyons. The channel alternates between gravel-bedded reaches that are incised into semi-consolidated glacial deposits and bedrock-bound reaches (7.7% of the reach between the towns of Quesnel and Hope). A continuous centreline aDcp survey was employed to measure longitudinal variation in slope, depth, depth-averaged velocity, and shear velocity. A total of 71 aDcp sectional surveys throughout the reach provided section widths (w), section-averaged depths (d), velocity distributions, and discharge (Q). Finally, air photo analysis using Google imagery provided channel widths at 0.5 km spacing. The survey reach was subdivided into 10 morphological sub-reaches, which ranged from alluvial gravel-bed reaches with relatively moderate slope to steep non-alluvial rock-walled canyons. The resulting data provide a unique opportunity to evaluate the influence of bedrock confinement on river hydrodynamics and channel geometry. Continuous centreline longitudinal aDcp data and the widths from air photo analysis were grouped within each sub-reach based on presence of bedrock confinement on both banks, either bank, or neither bank. The results demonstrate that river widths decreased and water depths, flow velocities, and shear velocities increased from the alluvial sub-reaches to the semi-alluvial reaches to the canyon reaches. Within each sub-reach, locations with bedrock encroachment on both banks were also narrower and deeper, but had lower depth-averaged velocity and shear velocity. Sectional geometry data were homogenized along the river (to compensate increasing flows at tributary junctions) by computing w/Q^{1/2} and d/Q^{1/3}, following commonly observed scaling relations. Alluvial reaches are 2.3x wider than rock-bound reaches (from the more abundant imagery data) and 0.60x as deep (from aDcp sections), implying that mean velocity is accelerated in rock reaches by 38%. There is also variation from reach to reach along the river controlled by variation in rock lithologies, with the narrowest canyons occurring in Fraser Canyon proper (w/Q^{1/2} = 0.083 compared with 1.4 elsewhere). The uppermost (';Marguerite') and lowermost (';Agassiz') alluvial reaches are considerably wider (w/Q^{1/2}= 3.9 and 7.1 respectively) than intervening ones ( 2.35). These reaches have lower gradients and exhibit wandering channels. Because of lithological control, the downstream hydraulic geometry of the river does not, in fact, conform with the common pattern, even when sections are analyzed according to boundary material. However, river gradient is well correlated with scaled width; inversely for gravel reaches and directly, but with little sensitivity, for rock-bound reaches.

Altitude of the water table in the alluvial and Wilcox aquifers in the vicinity of Richland and Tehuacana creeks and the Trinity River, Texas, December 1979

USGS Publications Warehouse

Garza, Sergio

1980-01-01

This map shows the altitude of the water table in the alluvial and Wilcox aquifers in the vicinity of Richland and Tehuacana Creeks and the Trinity River, Tex., in December 1979. The water-table contours were constructed on the basis of water-level control derived from an inventory of shallow wells in the area, topographic maps, and field locations of numerous small springs and seeps. (USGS)

Seasonal changes in ground-water levels in the shallow aquifer near Hagerman and the Pecos River, Chaves County, New Mexico

USGS Publications Warehouse

Garn, H.S.

1988-01-01

The Pecos River near Hagerman in Chaves County, New Mexico, historically has been a gaining stream. In 1938, the slope of the water table in the shallow alluvial aquifer near Hagerman was toward the Pecos River. By 1950, a large water-table depression had formed in the alluvial aquifer southwest of Hagerman. Continued enlargement of this depression could reverse the direction of groundwater flow to the Pecos River. Water levels were measured during 1981-85 in wells along a section extending from the Pecos River to a point within the depression. Although the water-table depression has not caused a perennial change in direction of groundwater flow, it has caused a seasonal reversal in the slope of the water table between the river and the depression during the growing season when pumpage from the shallow aquifer is the greatest. (USGS)

Climatic, geomorphic, and archaeological implications of a late Quaternary alluvial chronology for the lower Salt River, Arizona, USA

NASA Astrophysics Data System (ADS)

Huckleberry, Gary; Onken, Jill; Graves, William M.; Wegener, Robert

2013-03-01

Recent archaeological excavations along the lower Salt River, Arizona resulted in the unexpected discovery of buried late Pleistocene soils and cultural features dating 5800-7100 cal YBP (Early Archaic), the latter representing the earliest evidence of human activity in the lower Salt River floodplain thus far identified. Because the lower Salt River floodplain has been heavily impacted by recent agriculture and urbanization and contains few stratigraphic exposures, our understanding of the river's geological history is limited. Here we present a late Quaternary alluvial chronology for a segment of the lower Salt River based on 19 accelerator mass spectrometry 14C and four optically stimulated luminescence ages obtained during two previous geoarchaeological investigations. Deposits are organized into allostratigraphic units and reveal a buried late Pleistocene terrace inset into middle-to-late Pleistocene terrace deposits. Holocene terrace fill deposits unconformably cap the late Pleistocene terrace tread in the site area, and the lower portion of this fill contains the Early Archaic archaeological features. Channel entrenchment and widening ~ 900 cal YBP eroded much of the older terrace deposits, leaving only a remnant of fill containing the buried latest Pleistocene and middle-to-late Holocene deposits preserved in the site area. Subsequent overbank deposition and channel filling associated with a braided channel system resulted in the burial of the site by a thin layer of flood sediments. Our study confirms that the lower Salt River is a complex mosaic of late Quaternary alluvium formed through vertical and lateral accretion, with isolated patches of buried soils preserved through channel avulsion. Although channel avulsion is linked to changes in sediment load and discharge and may have climatic linkages, intrinsic geomorphic and local base level controls limit direct correlations of lower Salt River stratigraphy to other large rivers in the North American Southwest.

Reconnaissance of alluvial fans as potential sources of gravel aggregate, Santa Cruz River valley, Southeast Arizona

USGS Publications Warehouse

Lindsey, David A.; Melick, Roger

2002-01-01

This investigation was conducted to provide information on the aggregate potential of alluvial fan sediments in the Santa Cruz River valley. Pebble lithology, roundness, and particle size were determined in the field, and structures and textures of alluvial fan sediments were photographed and described. Additional measurements of particle size on digital photographs were made on a computer screen. Digital elevation models were acquired and compiled for viewing the areal extent of selected fans. Alluvial fan gravel in the Santa Cruz River valley reflects the lithology of its source. Gravel derived from granitic and gneissic terrane of the Tortolita, Santa Catalina, and Rincon Mountains weathers to grus and is generally inferior for use as aggregate. Gravel derived from the Tucson, Sierrita, and Tumacacori Mountains is composed mostly of angular particles of volcanic rock, much of it felsic in composition. This angular volcanic gravel should be suitable for use in asphalt but may require treatment for alkali-silica reaction prior to use in concrete. Gravel derived from the Santa Rita Mountains is of mixed plutonic (mostly granitic rocks), volcanic (mostly felsic rocks), and sedimentary (sandstone and carbonate rock) composition. The sedimentary component tends to make gravel derived from the Santa Rita Mountains slightly more rounded than other fan gravel. The coarsest (pebble, cobble, and boulder) gravel is found near the heads (proximal part) of alluvial fans. At the foot (distal part) of alluvial fans, most gravel is pebble-sized and interbedded with sand and silt. Some of the coarsest gravel was observed near the head of the Madera Canyon, Montosa Canyon, and Esperanza Wash fans. The large Cienega Creek fan, located immediately south and southeast of Tucson, consists entirely of distal-fan pebble gravel, sand, and silt.

Fragmented Landscapes in the San Gorgonio Pass Region: Insights into Quaternary Strain History of the Southern San Andreas Fault System

NASA Astrophysics Data System (ADS)

Kendrick, K. J.; Matti, J. C.; Landis, G. P.; Alvarez, R. M.

2006-12-01

The San Gorgonio Pass (SGP) region is a zone of structural complexity within the southern San Andreas Fault system that is characterized by (1) multiple strands of the San Andreas Fault (SAF), (2) intense and diverse microseismicity, (3) contraction within the SGP fault zone (SGPfz), and (4) complex and diverse landforms - all a consequence of structural complications in the vicinity of the southeastern San Bernardino Mountains (SBM). Multiple strands of the SAF zone in the SGP region partition the landscape into discrete geomorphic/geologic domains, including: San Gorgonio Mountain (SGM), Yucaipa Ridge (YR), Kitching Peak (KP), Pisgah Peak (PP), and Coachella Valley (CV) domains. The morphology of each domain reflects the tectonic history unique to that region. Development of the SGP knot in the Mission Creek strand of the SAF (SAFmi) led to westward deflection of the SAFmi, juxtaposition of the KP, PP, and SGM domains, initiation of uplift of YR domain along thrust faults in headwaters of San Gorgonio River, and development of the San Jacinto Fault. Slip on the SAF diminished as a result, thereby allowing integrated drainage systems to develop in the greater SGP region. San Gorgonio River, Whitewater River, and Mission Creek are discrete drainages that transport sediment across the SGM, YR, PP, KP, and CV domains into alluvial systems peripheral to the SGP region. There, depositional units (San Timoteo Formation, upper member, deformed gravels of Whitewater River) all contain clasts of SBM-type and San Gabriel Mountain-type basement, thus constraining slip on the SAF in the SGP region. Middle and late Pleistocene slip on the Mill Creek strand of the SAF (SAFm) in the SGP region has attempted to bypass the SGP knot, and has disrupted landscapes established during SAFmi quiescence. Restoration of right-slip on the SAFm is key to deciphering landscape history. Matti and others (1985, 1992) proposed that a bi-lobed alluvial deposit in the Raywood Flats area has been displaced by 8-10 km from entrenched bedrock drainages north of the SAFm (North Fork Whitewater River and Hell-For-Sure Canyon). This restoration, along with restoration of 3-4 km of dextral-slip along SAFmi, leads to an integrated drainage network that extended from San Gorgonio Peak southward across the SAFm and SAFmi, through the San Timoteo drainage basin and ultimately to the Santa Ana River drainage. Following final slip on the SAFmi, which occurred between approximately 1.2 and 0.5 Ma, the 8-10 km dextral-slip reconstruction on the SAFm can be used to restore the ancestral Mission Creek drainage system, which has always flowed southeast. A large alluvial-fan complex that overlies the SAFmi strand developed where the ancestral Mission Creek River debouched into the Coachella Valley. Analysis of cosmogenic radionuclides (21Ne from quartz) from surface boulders indicates that oldest deposits in the fan complex are about 400ka old, compatible with pedogenic development on the oldest surface. Approximately 2-4 km dextral slip on the youngest strands of the SAF (Banning and Garnet Hill) represents the latest bypass of the SGP structural knot. Cumulative displacement on all strands of the SAF in the greater SGP region appears to have been no more than ~18 km since inception of the left step in the SAFmi. Regional evidence suggests that this event initiated at ~1.2Ma, leading to a Quaternary slip rate on the SAF at SGP of no more than 10-15 mm/yr.

Using 3D geological modelling and geochemical mixing models to characterise alluvial aquifer recharge sources in the upper Condamine River catchment, Queensland, Australia.

PubMed

Martinez, Jorge L; Raiber, Matthias; Cendón, Dioni I

2017-01-01

The influence of mountain front recharge on the water balance of alluvial valley aquifers located in upland catchments of the Condamine River basin in Queensland, Australia, is investigated through the development of an integrated hydrogeological framework. A combination of three-dimensional (3D) geological modelling, hydraulic gradient maps, multivariate statistical analyses and hydrochemical mixing calculations is proposed for the identification of hydrochemical end-members and quantification of the relative contributions of each end-member to alluvial aquifer recharge. The recognised end-members correspond to diffuse recharge and lateral groundwater inflows from three hydrostratigraphic units directly connected to the alluvial aquifer. This approach allows mapping zones of potential inter-aquifer connectivity and areas of groundwater mixing between underlying units and the alluvium. Mixing calculations using samples collected under baseflow conditions reveal that lateral contribution from a regional volcanic aquifer system represents the majority (41%) of inflows to the alluvial aquifer. Diffuse recharge contribution (35%) and inflow from two sedimentary bedrock hydrostratigraphic units (collectively 24%) comprise the remainder of major recharge sources. A detailed geochemical assessment of alluvial groundwater evolution along a selected flowpath of a representative subcatchment of the Condamine River basin confirms mixing as a key process responsible for observed spatial variations in hydrochemistry. Dissolution of basalt-related minerals and dolomite, CO 2 uptake, ion-exchange, precipitation of clay minerals, and evapotranspiration further contribute to the hydrochemical evolution of groundwater in the upland alluvial aquifer. This study highlights the benefits of undertaking an integrated approach that combines multiple independent lines of evidence. The proposed methods can be applied to investigate processes associated with inter-aquifer mixing, including groundwater contamination resulting from depressurisation of underlying geological units hydraulically connected to the shallower water reservoirs. Copyright © 2016 Elsevier B.V. All rights reserved.

Late Quaternary alluvial fans of Emli Valley in the Ecemiş Fault Zone, south central Turkey: Insights from cosmogenic nuclides

NASA Astrophysics Data System (ADS)

Akif Sarıkaya, M.; Yıldırım, Cengiz; Çiner, Attila

2015-01-01

Alluvial fans within the paraglacial Ecemiş River drainages on the Aladağlar Mountains in south central Turkey were studied using geomorphological, sedimentological, and chlorine-36 terrestrial cosmogenic nuclide (TCN) surface exposure dating methods to examine the timing of alluvial fan abandonment/incision, and to understand the role of climatic and tectonic processes in the region. These alluvial fan complexes are among the best-preserved succession of alluvial fans in Turkey and they were offset by the major strike-slip Ecemiş Fault of the Central Anatolian Fault Zone. The alluvial fans are mostly composed of well-lithified limestone cobbles (5 to 25 cm in size), and comprise crudely stratified thick beds with a total thickness reaching up to about 80 m. TCN surface exposure dating indicates that the oldest alluvial fan surface (Yalak Fan) was likely formed and subsequently abandoned latest by 136.0 ± 23.4 ka ago, largely on the transition of the Penultimate Glaciation (Marine Isotope Stage 6, MIS 6) to the Last Interglacial (MIS 5) (i.e. Termination II). The second set of alluvial fan (Emli Fan) was possibly developed during the Last Interglacial (MIS 5), and incised twice by between roughly 97.0 ± 13.8 and 81.2 ± 13.2 ka ago. A younger alluvial fan deposit placed on relatively older erosional terraces of the Emli Fan suggests that it may have been produced during the Last Glacial Cycle (MIS 2). These events are similar to findings from other fluvial and lacustrine deposits throughout central Anatolia. The incision times of the Ecemiş alluvial fan surfaces largely coincide with major climatic shifts from the cooler glacial periods to warmer interglacial/interstadial conditions. This indicates that alluvial fans were produced by outwash sediments of paleoglaciers during cooler conditions, and, later, when glaciers started to retreat due to a major warming event, the excess water released from the glaciers incised the pre-existing fan surfaces. An alluvial fan in the study area was also cut by the Ecemiş Fault, highlighting the influence of tectonics on fan development. It was offset vertically 35 ± 3 m since at least 97.0 ± 13.8 ka, which suggests a 0.36 ± 0.06 mm a- 1 vertical slip-rate of the fault.

Characteristics of sedimentary structures in coarse-grained alluvial rivers

NASA Astrophysics Data System (ADS)

Ackerley, David; Powell, Mark

2013-04-01

The characteristics of coarse-grained alluvial surfaces have important implications for the estimation of flow resistance, entrainment thresholds and sediment transport rates in gravel-bed rivers. This area of research has, thus, demanded attention from geomorphologists, sedimentologists, and river engineers. The majority of research has focused towards understanding the characteristics and adjustments in surface grain size. Bed stability, however, is not ultimately defined by particle size but how grains are arranged within the bed surface. For example, by the organisation of particles into a variety of grain and form scale sedimentary structures and bedforms (e.g. imbrication; pebble clusters, stone nets, transverse ribs). While it is widely acknowledged sedimentary structuring must be considered within estimates of flow resistance and sediment transport, relatively little is known about the structural properties of water-worked river gravels. As a consequence, we remain woefully ignorant of this important aspect of gravel-bed river sedimentology. The aim of this poster is to present some preliminary results of a study designed to characterise the morphodynamics of sedimentary structures in coarse-grained alluvial rivers and their implications upon entrainment thresholds and sediment transport rates. The poster focuses on investigating the variability in grain and form scale sedimentary structuring across a number of field sites. Representative patches of three gravel bars on the Rivers Wharfe, Manifold and Afon Elan, UK, have been surveyed using a Leica HDS 3000 Terrestrial Laser Scanner. The resultant raw point-cloud data, recorded at a 4mm resolution, has been registered, filtered, and interpolated to produce highly detailed 2½D digital elevation models of gravel-bed surface topography. These surfaces have been analysed using a number of structural parameters including bed elevation probability distribution function statistics (standard deviation, skewness, kurtosis), semivariograms, and inclination indices. This research enhances our understanding of alluvial bed surface structures and lays the foundations for developing a more detailed understanding of their morphodynamics.

Weathering processes and the composition of inorganic material transported through the orinoco river system, Venezuela and Colombia

USGS Publications Warehouse

Stallard, R.F.; Koehnken, L.; Johnsson, M.J.

1991-01-01

The composition of river-borne material in the Orinoco River system is related primarily to erosion regime, which in turn is related to tectonic setting; especially notable is the contrast between material derived from tectonically active mountain belts and that from stable cratonic regions. For a particular morpho-tectonic region, the compositional suites of suspended sediment, bed material, overback deposits, and dissolved phases are fairly uniform are are typically distinct from whose of other regions. For each region, a consistent set of chemical weathering reactions can be formulated to explain the composition of dissolved and solid loads. In developing these formulations, erosion on slopes and storage of solids in soils and alluvial sediments are important considerations. Compositionally verymature sediment is derived from areas of thick soils where erosion is transport limited and from areas where sediments are stored for extended periods of time in alluvial deposits. Compositionally immature sediments are derived from tectonically active mountain belts where erosion is weathering limited. Weathering-limited erosion also is important in the elevated parts of the Guayana Shield within areas of sleep topography. Compared to the mountain belts, sediments derived from elevated parts of the Shield are more mature. A greater degree of chemical weathering seems to be needed to erode the rock types typical of the Shield. The major-element chemistry and mineral composition of sediment delivered by the Orinoco River to the ocean are controlled by rivers that have their headwaters in mountain belts and cross the Llanos, a region of alluvial plains within the foreland basin. The composition of sediments in rivers that drain the Shield seems to be established primarily at the site of soil formation, whereas for rivers that drain the mountain belts, additional weathering occurs during s episodes of storage on alluvial plains as sediments are transported across the Llanos to the main stem of the Orinoco. After mixing into the main stem, there seems to be little subsequent alteration of sediment. ?? 1991.

Late Quaternary drainage evolution in response to fold growth in the northern Chinese Tian Shan foreland

NASA Astrophysics Data System (ADS)

Lu, Honghua; Wu, Dengyun; Cheng, Lu; Zhang, Tianqi; Xiong, Jianguo; Zheng, Xiangmin; Li, Youli

2017-12-01

Alluvial units are important in understanding the interactions of antecedent drainage evolution with fold growth along the flanks of active orogenic belts. This is demonstrated by the Anjihai River in the northern Chinese Tian Shan foreland, which at present flows northward cutting sequentially through the Nananjihai anticline, the Huoerguos anticline, and the Anjihai anticline. Three episodes of alluviation designated as fans Fa, Fb, and Fc are identified for the Anjihai River. These three alluvial terrain features comprise a series of terraces, where the topographic characteristics, geomorphologic structure, and up-warped longitudinal profiles indicate continuous uplift and lateral propagation of the Halaande anticline and the Anjihai anticline over the past 50 ky. Shortly after 3.6 ka when the oldest terrace during the period of the fan Fb sedimentation was formed, significant rock uplift at the overlapping zone of the Anjihai anticline and the Halaande anticline led to the eastward deflection of the antecedent Anjihai River. A series of local terraces with elevation decreasing eastward indicate the gradual eastward migration of the channel of the Anjihai River during the period of the fan Fc sedimentation. Finally the Anjihai River occupied the previous course of the Jingou River when the latter was deflected eastward in response to rock uplift of the Anjihai anticline, presently flowing across the eastern tip of the Anjihai anticline.

RIVERINE RESTORATION STRATEGIES: PATTERN AND PROCESS IN A LARGE ALLUVIAL RIVER

EPA Science Inventory

The Willamette River in western Oregon is the tenth largest river in the conterminous U. S. Plans being developed to restore ecological function to the main corridor of the river. Our riverine research has developed a basic understanding of some of the ecological functions and ...

Alluvial aquifers in the Mzingwane catchment: Their distribution, properties, current usage and potential expansion

NASA Astrophysics Data System (ADS)

Moyce, William; Mangeya, Pride; Owen, Richard; Love, David

The Mzingwane River is a sand filled channel, with extensive alluvial aquifers distributed along its banks and bed in the lower catchment. LandSat TM imagery was used to identify alluvial deposits for potential groundwater resources for irrigation development. On the false colour composite band 3, band 4 and band 5 (FCC 345) the alluvial deposits stand out as white and dense actively growing vegetation stands out as green making it possible to mark out the lateral extent of the saturated alluvial plain deposits using the riverine fringe and vegetation . The alluvial aquifers form ribbon shaped aquifers extending along the channel and reaching over 20 km in length in some localities and are enhanced at lithological boundaries. These alluvial aquifers extend laterally outside the active channel, and individual alluvial aquifers have been measured with area ranging from 45 ha to 723 ha in the channels and 75 ha to 2196 ha on the plains. The alluvial aquifers are more pronounced in the Lower Mzingwane, where the slopes are gentler and allow for more sediment accumulation. Estimated water resources potential ranges between 175,000 m 3 and 5,430,000 m 3 in the channels and between 80,000 m 3 and 6,920,000 m 3 in the plains. Such a water resource potential can support irrigation ranging from 18 ha to 543 ha for channels alluvial aquifers and 8 ha to 692 ha for plain alluvial aquifers. Currently, some of these aquifers are being used to provide water for domestic use, livestock watering and dip tanks, commercial irrigation and market gardening. The water quality of the aquifers in general is fairly good due to regular recharge and flushing out of the aquifers by annual river flows and floodwater. Water salinity was found to increase significantly in the end of the dry season, and this effect was more pronounced in water abstracted from wells on the alluvial plains. During drought years, recharge is expected to be less and if the drought is extended water levels in the aquifers may drop substantially, increasing salinity problems.

Assessing the impact of managed aquifer recharge on seasonal low flows in a semi-arid alluvial river

NASA Astrophysics Data System (ADS)

Ronayne, M. J.; Roudebush, J. A.; Stednick, J. D.

2016-12-01

Managed aquifer recharge (MAR) is one strategy that can be used to augment seasonal low flows in alluvial rivers. Successful implementation requires an understanding of spatio-temporal groundwater-surface water exchange. In this study we conducted numerical groundwater modeling to analyze the performance of an existing MAR system in the South Platte River Valley in northeastern Colorado (USA). The engineered system involves a spatial reallocation of water during the winter months; alluvial groundwater is extracted near the river and pumped to upgradient recharge ponds, with the intent of producing a delayed hydraulic response that increases the riparian zone water table (and therefore streamflow) during summer months. Higher flows during the summer are required to improve riverine habitat for threatened species in the Platte River. Modeling scenarios were constrained by surface (streamflow gaging) and subsurface (well data) measurements throughout the study area. We compare two scenarios to analyze the impact of MAR: a natural base case scenario and an active management scenario that includes groundwater pumping and managed recharge. Steady-periodic solutions are used to evaluate the long-term stabilized behavior of the stream-aquifer system with and without pumping/recharge. Streamflow routing is included in the model, which permits quantification of the timing and location of streamflow accretion (increased streamflow associated with MAR). An analysis framework utilizing capture concepts is developed to interpret seasonal changes in head-dependent flows to/from the aquifer, including groundwater-surface water exchange that impacts streamflow. Results demonstrate that accretion occurs during the target low-flow period but is not limited to those months, highlighting an inefficiency that is a function of the aquifer geometry and hydraulic properties. The results of this study offer guidance for other flow augmentation projects that rely on water storage in shallow alluvial aquifers.

Modeling 3-D permeability distribution in alluvial fans using facies architecture and geophysical acquisitions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Lin; Gong, Huili; Dai, Zhenxue

Alluvial fans are highly heterogeneous in hydraulic properties due to complex depositional processes, which make it difficult to characterize the spatial distribution of the hydraulic conductivity ( K). An original methodology is developed to identify the spatial statistical parameters (mean, variance, correlation range) of the hydraulic conductivity in a three-dimensional (3-D) setting by using geological and geophysical data. More specifically, a large number of inexpensive vertical electric soundings are integrated with a facies model developed from borehole lithologic data to simulate the log 10( K) continuous distributions in multiple-zone heterogeneous alluvial megafans. The Chaobai River alluvial fan in the Beijing Plain,more » China, is used as an example to test the proposed approach. Due to the non-stationary property of the K distribution in the alluvial fan, a multiple-zone parameterization approach is applied to analyze the conductivity statistical properties of different hydrofacies in the various zones. The composite variance in each zone is computed to describe the evolution of the conductivity along the flow direction. Consistently with the scales of the sedimentary transport energy, the results show that conductivity variances of fine sand, medium-coarse sand, and gravel decrease from the upper (zone 1) to the lower (zone 3) portion along the flow direction. In zone 1, sediments were moved by higher-energy flooding, which induces poor sorting and larger conductivity variances. The composite variance confirms this feature with statistically different facies from zone 1 to zone 3. Lastly, the results of this study provide insights to improve our understanding on conductivity heterogeneity and a method for characterizing the spatial distribution of  K in alluvial fans.« less

Modeling 3-D permeability distribution in alluvial fans using facies architecture and geophysical acquisitions

DOE PAGES

Zhu, Lin; Gong, Huili; Dai, Zhenxue; ...

2017-02-03

Alluvial fans are highly heterogeneous in hydraulic properties due to complex depositional processes, which make it difficult to characterize the spatial distribution of the hydraulic conductivity ( K). An original methodology is developed to identify the spatial statistical parameters (mean, variance, correlation range) of the hydraulic conductivity in a three-dimensional (3-D) setting by using geological and geophysical data. More specifically, a large number of inexpensive vertical electric soundings are integrated with a facies model developed from borehole lithologic data to simulate the log 10( K) continuous distributions in multiple-zone heterogeneous alluvial megafans. The Chaobai River alluvial fan in the Beijing Plain,more » China, is used as an example to test the proposed approach. Due to the non-stationary property of the K distribution in the alluvial fan, a multiple-zone parameterization approach is applied to analyze the conductivity statistical properties of different hydrofacies in the various zones. The composite variance in each zone is computed to describe the evolution of the conductivity along the flow direction. Consistently with the scales of the sedimentary transport energy, the results show that conductivity variances of fine sand, medium-coarse sand, and gravel decrease from the upper (zone 1) to the lower (zone 3) portion along the flow direction. In zone 1, sediments were moved by higher-energy flooding, which induces poor sorting and larger conductivity variances. The composite variance confirms this feature with statistically different facies from zone 1 to zone 3. Lastly, the results of this study provide insights to improve our understanding on conductivity heterogeneity and a method for characterizing the spatial distribution of  K in alluvial fans.« less

Static and dynamic characterization of alluvial deposits in the Tiber River Valley: New data for assessing potential ground motion in the City of Rome

NASA Astrophysics Data System (ADS)

Bozzano, F.; Caserta, A.; Govoni, A.; Marra, F.; Martino, S.

2008-01-01

The paper presents the results of a case study conducted on the Holocene alluvial deposits of the Tiber River valley, in the city of Rome. The main test site selected for the study, Valco S. Paolo, is located about 2 km South of Rome's historical centre. The alluvial deposits were dynamically characterized in a comprehensive way via site investigations and geotechnical laboratory tests. Normalized shear modulus decay and damping curves (G/G0 and D/D0 vs γ) were obtained for the dominantly fine-grained levels. The curves demonstrate that these levels have a more marked shear stiffness decay if compared with the underlying Pliocene bedrock. Decay curves from laboratory tests for the Tiber alluvia correlated well with the trend of the function proposed by Hardin and Drnevich, making it possible to derive their specific interpolation function coefficients. Use was made of the extrapolation of the findings from the Valco S. Paolo test site to a large part of Rome's historical centre by means of two other test sites, supported by an engineering-geology model of the complex spatial distribution of the Tiber alluvia. The experimental Valco S. Paolo Vs profile was extrapolated to the other test sites on the basis of a stratigraphic criterion; the analysis of seismic noise measurements, obtained for the three test sites, validated the engineering-geology based extrapolation and showed that the main rigidity contrast occurs inside the alluvial body (at the contact with the underlying basal gravel-level G) and not between the alluvia and the Plio-Pleistocene bedrock, composed of highly consistent clay (Marne Vaticane). The 1D modeling of local seismic response to the maximum expected earthquakes in the city of Rome confirms that the deposits have one principal mode of vibration at about 1 Hz. However, the simulation also evidenced that the silty-clay deposits (level C), making up the most part of the Tiber alluvial body, play a key role in characterizing the soil column deformation profile since it can be affected by non linear effects induced by the maximum expected earthquake when some stratigraphic conditions are satisfied.

Fishes in paleochannels of the Lower Mississippi River alluvial valley: A national treasure

USGS Publications Warehouse

Miranda, Leandro E.

2016-01-01

Fluvial geomorphology of the alluvial valley of the Lower Mississippi River reveals a fascinating history. A prominent occupant of the valley was the Ohio River, estimated to have flowed 25,000 years ago over western Tennessee and Mississippi to join the Mississippi River north of Baton Rouge, Louisiana, 750–800 km south of the present confluence. Over time, shifts in the Mississippi and Ohio rivers toward their contemporary positions have left a legacy of abandoned paleochannels supportive of unique fish assemblages. Relative to channels abandoned in the last 500 years, paleochannels exhibit harsher environmental conditions characteristic of hypereutrophic lakes and support tolerant fish assemblages. Considering their ecological, geological, and historical importance, coupled with their primordial scenery, the hundreds of paleochannels in the valley represent a national treasure. Altogether, these waterscapes are endangered by human activities and would benefit from the conservation attention afforded to our national parks and wildlife refuges.

INFLUENCE OF SEDIMENT SUPPLY, LITHOLOGY, AND WOOD DEBRIS ON THE DISTRIBUTION OF BEDROCK AND ALLUVIAL CHANNELS

EPA Science Inventory

Field surveys in the Willapa River basin, Washington State, indicate that the drainage area?channel slope threshold describing the distribution of bedrock and alluvial channels is influenced by the underlying lithology and that local variations in sediment supply can overwhelm ba...

Hydrogeology and leachate plume delineation at a closed municipal landfill, Norman, Oklahoma

USGS Publications Warehouse

Becker, Carol J.

2002-01-01

The City of Norman operated a solid-waste municipal landfill at two sites on the Canadian River alluvium in Cleveland County, Oklahoma from 1970 to 1985. The sites, referred to as the west and east cells of the landfill, were originally excavations in the unconsolidated alluvial deposits and were not lined. Analysis of ground-water samples indicate that leachate from the west cell is discharging into an adjacent abandoned river channel, referred to as the slough, and is migrating downgradient in ground water toward the Canadian River. The report describes the hydrogeologic features at the landfill, including the topography of the bedrock, water-level changes in the alluvial aquifer, and delineates the leachate plume using specific conductance data. The leading edge of the leachate plume along the 35-80 transect extended over 250 meters downgradient of the west cell. The leading edge of the leachate plume along the 40-SOUTH transect had moved about 60 meters from the west cell in a south-southwesterly direction and had not moved past the slough as of 1997. Specific conductance measurements exceeding 7,000 microsiemens per centimeter at site 40 indicate the most concentrated part of the plume remained in the upper half of the alluvial aquifer adjacent to the west cell. The direction of ground-water flow in the alluvial aquifer surrounding the landfill was generally north-northeast to south-southwest toward the river. However, between the west cell and the slough along the 40-SOUTH transect, head measurements indicate a directional change to the east and southeast toward a channel referred to as the sewage outfall. Near the 35-80 transect, at 0.5 meter below the water table and at the base of the aquifer, the direction of ground-water flow was south-southeast with a gradient of about 30 centimeters per 100 meters. Generally, ground-water levels in the alluvial aquifer were higher during the winter months and lower during summer months, due to a normal decrease in precipitation and increased evapotranspiration in the summer. Hydrographs show temporal water-level changes in ground water and the slough, indicating a hydrologic connection between the alluvial aquifer and the slough.

Storing and sharing water in sand rivers: a water balance modelling approach

NASA Astrophysics Data System (ADS)

Love, D.; van der Zaag, P.; Uhlenbrook, S.

2009-04-01

Sand rivers and sand dams offer an alternative to conventional surface water reservoirs for storage. The alluvial aquifers that make up the beds of sand rivers can store water with minimal evaporation (extinction depth is 0.9 m) and natural filtration. The alluvial aquifers of the Mzingwane Catchment are the most extensive of any tributaries in the Limpopo Basin. The lower Mzingwane aquifer, which is currently underutilised, is recharged by managed releases from Zhovhe Dam (capacity 133 Mm3). The volume of water released annually is only twice the size of evaporation losses from the dam; the latter representing nearly one third of the dam's storage capacity. The Lower Mzingwane valley currently support commercial agro-businesses (1,750 ha irrigation) and four smallholder irrigation schemes (400 ha with provision for a further 1,200 ha). In order to support planning for optimising water use and storage over evaporation and to provide for more equitable water allocation, the spreadsheet-based balance model WAFLEX was used. It is a simple and userfriendly model, ideal for use by institutions such as the water management authorities in Zimbabwe which are challenged by capacity shortfalls and inadequate data. In this study, WAFLEX, which is normally used for accounting the surface water balance, is adapted to incorporate alluvial aquifers into the water balance, including recharge, baseflow and groundwater flows. Results of the WAFLEX modelling suggest that there is surplus water in the lower Mzingwane system, and thus there should not be any water conflicts. Through more frequent timing of releases from the dam and maintaining the alluvial aquifers permanently saturated, less evaporation losses will occur in the system and the water resources can be better shared to provide more irrigation water for smallholder farmers in the highly resource-poor communal lands along the river. Sand dams are needed to augment the aquifer storage system and improve access to water. An alternative to the current scenario was modelled in WAFLEX: making fuller use of the alluvial aquifers upstream and downstream of Zhovhe Dam. These alluvial aquifers have an estimated average water storage capacity of 0.37 Mm3 km

Hydrogeology and simulation of groundwater flow and analysis of projected water use for the Canadian River alluvial aquifer, western and central Oklahoma

USGS Publications Warehouse

Ellis, John H.; Mashburn, Shana L.; Graves, Grant M.; Peterson, Steven M.; Smith, S. Jerrod; Fuhrig, Leland T.; Wagner, Derrick L.; Sanford, Jon E.

2017-02-13

This report describes a study of the hydrogeology and simulation of groundwater flow for the Canadian River alluvial aquifer in western and central Oklahoma conducted by the U.S. Geological Survey in cooperation with the Oklahoma Water Resources Board. The report (1) quantifies the groundwater resources of the Canadian River alluvial aquifer by developing a conceptual model, (2) summarizes the general water quality of the Canadian River alluvial aquifer groundwater by using data collected during August and September 2013, (3) evaluates the effects of estimated equal proportionate share (EPS) on aquifer storage and streamflow for time periods of 20, 40, and 50 years into the future by using numerical groundwater-flow models, and (4) evaluates the effects of present-day groundwater pumping over a 50-year period and sustained hypothetical drought conditions over a 10-year period on stream base flow and groundwater in storage by using numerical flow models. The Canadian River alluvial aquifer is a Quaternary-age alluvial and terrace unit consisting of beds of clay, silt, sand, and fine gravel sediments unconformably overlying Tertiary-, Permian-, and Pennsylvanian-age sedimentary rocks. For groundwater-flow modeling purposes, the Canadian River was divided into Reach I, extending from the Texas border to the Canadian River at the Bridgeport, Okla., streamgage (07228500), and Reach II, extending downstream from the Canadian River at the Bridgeport, Okla., streamgage (07228500), to the confluence of the river with Eufaula Lake. The Canadian River alluvial aquifer spans multiple climate divisions, ranging from semiarid in the west to humid subtropical in the east. The average annual precipitation in the study area from 1896 to 2014 was 34.4 inches per year (in/yr).A hydrogeologic framework of the Canadian River alluvial aquifer was developed that includes the areal and vertical extent of the aquifer and the distribution, texture variability, and hydraulic properties of aquifer materials. The aquifer areal extent ranged from less than 0.2 to 8.5 miles wide. The maximum aquifer thickness was 120 feet (ft), and the average aquifer thickness was 50 ft. Average horizontal hydraulic conductivity for the Canadian River alluvial aquifer was calculated to be 39 feet per day, and the maximum horizontal hydraulic conductivity was calculated to be 100 feet per day.Recharge rates to the Canadian River alluvial aquifer were estimated by using a soil-water-balance code to estimate the spatial distribution of groundwater recharge and a water-table fluctuation method to estimate localized recharge rates. By using daily precipitation and temperature data from 39 climate stations, recharge was estimated to average 3.4 in/yr, which corresponds to 8.7 percent of precipitation as recharge for the Canadian River alluvial aquifer from 1981 to 2013. The water-table fluctuation method was used at one site where continuous water-level observation data were available to estimate the percentage of precipitation that becomes groundwater recharge. Estimated annual recharge at that site was 9.7 in/yr during 2014.Groundwater flow in the Canadian River alluvial aquifer was identified and quantified by a conceptual flow model for the period 1981–2013. Inflows to the Canadian River alluvial aquifer include recharge to the water table from precipitation, lateral flow from the surrounding bedrock, and flow from the Canadian River, whereas outflows include flow to the Canadian River (base-flow gain), evapotranspiration, and groundwater use. Total annual recharge inflows estimated by the soil-water-balance code were multiplied by the area of each reach and then averaged over the simulated period to produce an annual average of 28,919 acre-feet per year (acre-ft/yr) for Reach I and 82,006 acre-ft/yr for Reach II. Stream base flow to the Canadian River was estimated to be the largest outflow of groundwater from the aquifer, measured at four streamgages, along with evapotranspiration and groundwater use, which were relatively minor discharge components.Objectives for the numerical groundwater-flow models included simulating groundwater flow in the Canadian River alluvial aquifer from 1981 to 2013 to address groundwater use and drought scenarios, including calculation of the EPS pumping rates. The EPS for the alluvial and terrace aquifers is defined by the Oklahoma Water Resources Board as the amount of fresh water that each landowner is allowed per year per acre of owned land to maintain a saturated thickness of at least 5 ft in at least 50 percent of the overlying land of the groundwater basin for a minimum of 20 years.The groundwater-flow models were calibrated to water-table altitude observations, streamgage base flows, and base-flow gain to the Canadian River. The Reach I water-table altitude observation root-mean-square error was 6.1 ft, and 75 percent of residuals were within ±6.7 ft of observed measurements. The average simulated stream base-flow residual at the Bridgeport streamgage (07228500) was 8.8 cubic feet per second (ft3/s), and 75 percent of residuals were within ±30 ft3/s of observed measurements. Simulated base-flow gain in Reach I was 8.8 ft3/s lower than estimated base-flow gain. The Reach II water-table altitude observation root-mean-square error was 4 ft, and 75 percent of residuals were within ±4.3 ft of the observations. The average simulated stream base-flow residual in Reach II was between 35 and 132 ft3/s. The average simulated base-flow gain residual in Reach II was between 11.3 and 61.1 ft3/s.Several future predictive scenarios were run, including estimating the EPS pumping rate for 20-, 40-, and 50-year life of basin scenarios, determining the effects of current groundwater use over a 50-year period into the future, and evaluating the effects of a sustained drought on water availability for both reaches. The EPS pumping rate was determined to be 1.35 acre-feet per acre per year ([acre-ft/acre]/yr) in Reach I and 3.08 (acre-ft/acre)/yr in Reach II for a 20-year period. For the 40- and 50-year periods, the EPS rate was determined to be 1.34 (acre-ft/acre)/yr in Reach I and 3.08 (acre-ft/acre)/yr in Reach II. Storage changes decreased in tandem with simulated groundwater pumping and were minimal after the first 15 simulated years for Reach I and the first 8 simulated years for Reach II.Groundwater pumping at year 2013 rates for a period of 50 years resulted in a 0.2-percent decrease in groundwater-storage volumes in Reach I and a 0.6-percent decrease in the groundwater-storage volumes in Reach II. The small changes in storage are due to groundwater use by pumping, which composes a small percentage of the total groundwater-flow model budgets for Reaches I and II.A sustained drought scenario was used to evaluate the effects of a hypothetical 10-year drought on water availability. A 10-year period was chosen where the effects of drought conditions would be simulated by decreasing recharge by 75 percent. In Reach I, average simulated stream base flow at the Bridgeport streamgage (07228500) decreased by 58 percent during the hypothetical 10-year drought compared to average simulated stream base flow during the nondrought period. In Reach II, average simulated stream base flows at the Purcell streamgage (07229200) and Calvin streamgage (07231500) decreased by 64 percent and 54 percent, respectively. In Reach I, the groundwater-storage drought scenario resulted in a storage decline of 30 thousand acre-feet, or an average decline in the water table of 1.2 ft. In Reach II, the groundwater-storage drought scenario resulted in a storage decline of 71 thousand acre-feet, or an average decline in the water table of 2.0 ft.

Simulation of ground-water flow in the Cedar River alluvial aquifer flow system, Cedar Rapids, Iowa

USGS Publications Warehouse

Turco, Michael J.; Buchmiller, Robert C.

2004-01-01

Model results indicate that the primary sources of inflow to the modeled area are infiltration from the Cedar River (53.0 percent) and regional flow in the glacial and bedrock materials (34.1 percent). The primary sources of outflow from the modeled area are discharge to the Cedar River (45.4 percent) and pumpage (44.8 percent). Current steady-state pumping rates have increased the flow of water from the Cedar River to the alluvial aquifer by 43.8 cubic feet per second. Steady-state and transient hypothetical pumpage scenarios were used to show the relation between changes in pumpage and changes in infiltration of water from the Cedar River. Results indicate that more than 99 percent of the water discharging from municipal wells infiltrates from the Cedar River, that the time required for induced river recharge to equilibrate with municipal pumpage may be 150 days or more, and that ground-water availability in the Cedar Rapids area will not be significantly affected by doubling current pumpage as long as there is sufficient flow in the Cedar River to provide recharge.

Geologie study off gravels of the Agua Fria River, Phoenix, AZ

USGS Publications Warehouse

Langer, W.H.; Dewitt, E.; Adams, D.T.; O'Briens, T.

2010-01-01

The annual consumption of sand and gravel aggregate in 2006 in the Phoenix, AZ metropolitan area was about 76 Mt (84 million st) (USGS, 2009), or about 18 t (20 st) per capita. Quaternary alluvial deposits in the modern stream channel of the Agua Fria River west of Phoenix are mined and processed to provide some of this aggregate to the greater Phoenix area. The Agua Fria drainage basin (Fig. 1) is characterized by rugged mountains with high elevations and steep stream gradients in the north, and by broad alluvial filled basins separated by elongated faultblock mountain ranges in the south. The Agua Fria River, the basin’s main drainage, flows south from Prescott, AZ and west of Phoenix to the Gila River. The Waddel Dam impounds Lake Pleasant and greatly limits the flow of the Agua Fria River south of the lake. The southern portion of the watershed, south of Lake Pleasant, opens out into a broad valley where the river flows through urban and agricultural lands to its confluence with the Gila River, a tributary of the Colorado River.

Accounting for Consumptive Use of Lower Colorado River Water in Arizona, California, Nevada, and Utah

USGS Publications Warehouse

Owen-Joyce, Sandra J.; Wilson, Richard P.

1994-01-01

In the Colorado River valley between the east end of Lake Mead and the international boundary with Mexico (see figure), the river is the principal source of water for agricultural, domestic, municipal, industrial, hydroelectric-power generation, and recreational purposes. Water is stored in surface reservoirs and in the river aquifer---permeable sediments and sedimentary rocks that fill the lower Colorado River valley and adjacent tributary valleys. The hydraulic connection between the river and the river aquifer, overbank flow prior to building of the dams, and infiltration as the reservoirs filled allowed the sediments and sedimentary rocks to become saturated with water from the river. Ratios of isotopes of hydrogen and oxygen in water from wells indicate that most of the water in the river aquifer beneath the flood plain and in many places beneath the adjacent alluvial slopes originated from the river. The water table in the river aquifer extends from the river, beneath the flood plain, and under the alluvial slopes until it intersects bedrock. Precipitation in the surrounding mountains and inflow from tributary valleys also contribute small quantities of water to the river aquifer. Consumptive use of river water in the valley results from evapotranspiration by vegetation (crops and phreatophytes) on the flood plain, pumpage from wells to meet domestic and municipal needs, and pumpage from the river for export to areas in California, Arizona, and Nevada outside of the river valley. Most crops are grown on the flood plain; in a few areas, land on the adjacent terraces has been cultivated. Crops were grown on about 70 percent of the total vegetated area in 1984. Phreatophytes---natural vegetation that obtains water from the river aquifer---covered the remaining vegetated areas on the uncultivated flood plain. Most of the water used for irrigation is diverted or pumped directly from the river and reservoirs. Most of the water used for domestic and municipal purposes is pumped from wells on the flood plain, on adjacent alluvial slopes, and in tributary valleys. River water also is delivered to Mexico in accordance with an international treaty.

Aquifer depletion in the Lower Mississippi River Basin: challenges and solutions

USDA-ARS?s Scientific Manuscript database

The Lower Mississippi River Basin (LMRB) is an internationally-important region of intensive agricultural crop production that relies heavily on the underlying Mississippi River Valley Alluvial Aquifer (MRVAA) for irrigation. Extensive irrigation coupled with the region’s geology have led to signifi...

Reconstructing the transport history of pebbles on Mars

PubMed Central

Szabó, Tímea; Domokos, Gábor; Grotzinger, John P.; Jerolmack, Douglas J.

2015-01-01

The discovery of remarkably rounded pebbles by the rover Curiosity, within an exhumed alluvial fan complex in Gale Crater, presents some of the most compelling evidence yet for sustained fluvial activity on Mars. While rounding is known to result from abrasion by inter-particle collisions, geologic interpretations of sediment shape have been qualitative. Here we show how quantitative information on the transport distance of river pebbles can be extracted from their shape alone, using a combination of theory, laboratory experiments and terrestrial field data. We determine that the Martian basalt pebbles have been carried tens of kilometres from their source, by bed-load transport on an alluvial fan. In contrast, angular clasts strewn about the surface of the Curiosity traverse are indicative of later emplacement by rock fragmentation processes. The proposed method for decoding transport history from particle shape provides a new tool for terrestrial and planetary sedimentology. PMID:26460507

Stochastic Spectral Analysis for Characterizing Hydraulic Diffusivity in an Alluvial Fan Aquifer with River Stimulus

NASA Astrophysics Data System (ADS)

Wang, Y. L.; Zha, Y.; Yeh, T. C. J.; Wen, J. C.

2015-12-01

Estimation of subsurface hydraulic diffusivity was carried out to understand the characteristics of Zhuoshui River alluvial fan, Taiwan. The fan, an important agricultural and industrial region with high water demand, is located at middle Taiwan with an area of 1800 km2. The prior geo-investigations suggest that the main recharge region of the fan is at an apex along the river. The distribution of soil hydraulic diffusivity was estimated by fusing naturally recurring stimulus provided by river and groundwater head. Specifically, the variance and power spectrum provided by temporal and spatial change of groundwater head in response to river stage variations are analyzed to estimate hydraulic diffusivity distribution. It is found that the hydraulic diffusivity of the fan is at the range from 0.08 to 16 m2/s. The average hydraulic diffusivity at the apex, middle, and tail of the fan along the river is about 0.4, 0.6, and 1.0 m2/s, respectively.

Degradation of the Mitchell River fluvial megafan by alluvial gully erosion increased by post-European land use change, Queensland, Australia

NASA Astrophysics Data System (ADS)

Shellberg, J. G.; Spencer, J.; Brooks, A. P.; Pietsch, T. J.

2016-08-01

Along low gradient rivers in northern Australia, there is widespread gully erosion into unconfined alluvial deposits of active and inactive floodplains. On the Mitchell River fluvial megafan in northern Queensland, river incision and fan-head trenching into Pleistocene and Holocene megafan units with sodic soils created the potential energy for a secondary cycle of erosion. In this study, rates of alluvial gully erosion into incipiently-unstable channel banks and/or pre-existing floodplain features were quantified to assess the influence of land use change following European settlement. Alluvial gully scarp retreat rates were quantified at 18 sites across the megafan using recent GPS surveys and historic air photos, demonstrating rapid increases in gully area of 1.2 to 10 times their 1949 values. Extrapolation of gully area growth trends backward in time suggested that the current widespread phase of gullying initiated between 1880 and 1950, which is post-European settlement. This is supported by young optically stimulated luminescence (OSL) dates of gully inset-floodplain deposits, LiDAR terrain analysis, historic explorer accounts of earlier gully types, and archival records of cattle numbers and land management. It is deduced that intense cattle grazing and associated disturbance concentrated in the riparian zones during the dry season promoted gully erosion in the wet season along steep banks, adjacent floodplain hollows and precursor gullies. This is a result of reduced native grass cover, increased physical disturbance of soils, and the concentration of water runoff along cattle tracks, in addition to fire regime modifications, episodic drought, and the establishment of exotic weed and grass species. Geomorphic processes operating over geologic time across the fluvial megafan predisposed the landscape to being pushed by land used change across an intrinsically close geomorphic threshold towards instability. The evolution of these alluvial gullies is discussed in terms of their initiation, development, future growth, and stabilisation, and the numerous natural and anthropogenic factors influencing their erosion.

Effects of surface-water irrigation on sources, fluxes, and residence times of water, nitrate, and uranium in an alluvial aquifer

USGS Publications Warehouse

Böhlke, J.K.; Verstraeten, Ingrid M.; Kraemer, T.F.

2007-01-01

Effects of surface-water irrigation on an alluvial aquifer were evaluated using chemical and isotopic data including ??2H, ??18O, 3H, ??3He, Ar, Ne, N2, ??15N, and 234U/238U activity ratios in a transect of nested wells in the North Platte River valley in western Nebraska, USA. The data were used to evaluate sources and fluxes of H2O, NO3- and U, all of which were strongly affected by irrigated agriculture. Combined results indicate that the alluvial aquifer was dominated by irrigation water that had distinctive chemical and isotopic features that were inherited from the North Platte River or acquired from agricultural soils or recharge processes. Values of ??2H, ??18O, Ar and Ne indicate that most of the ground water in the alluvial aquifer was irrigation water that was derived from the North Platte River and distributed during the growing season. The irrigation water was identified by an evaporated isotopic signature that was acquired by the river in major upstream reservoirs in Wyoming, and by relatively warm gas-equilibration temperatures related to warm-season recharge. Apparent 3H-3He ages indicate that the ground water in the alluvium was stratified and mostly 3.0 m/a. Age gradients and NO3- concentrations indicate that recharge occurred by a combination of focused leakage from irrigation canals (rapid local recharge, low NO3-) and distributed infiltration beneath the irrigated agricultural fields (lower recharge, high NO3-). Large amounts of U with relatively low 234U/238U activity ratios were present in the alluvial aquifer as a result of irrigation with U-bearing river water, and minor amounts of U with higher 234U/238U activity ratios were added locally from basal and underlying volcanic-rich sediments. Distributions of NO3-, ?? 15 N [NO3-], dissolved gases, and ground-water ages indicate that NO3- concentrations increased and ?? 15 N [NO3-] values decreased in distributed recharge in the last few decades, possibly in relation to a documented increase in the agricultural use of artificial fertilizers. Canal leakage caused substantial dilution of NO3- within the alluvial aquifer, whereas denitrification occurred mainly near the bottom of the alluvium. The average residence time of the irrigation water within the aquifer was relatively short (about 9 a) and reactions such as respiration, denitrification and U exchange in the saturated zone had relatively little effect on the overall composition of the alluvial ground water in comparison to what they might have had in the absence of irrigation recharge.

Sediment dynamics in the restored reach of the Kissimmee River Basin, Florida: A vast subtropical riparian wetland

USGS Publications Warehouse

Schenk, E.R.; Hupp, C.R.; Gellis, A.

2012-01-01

Historically, the Kissimmee River Basin consisted of a broad nearly annually inundated riparian wetland similar in character to tropical Southern Hemisphere large rivers. The river was channelized in the 1960s and 1970s, draining the wetland. The river is currently being restored with over 10 000 hectares of wetlands being reconnected to 70 river km of naturalized channel. We monitored riparian wetland sediment dynamics between 2007 and 2010 at 87 sites in the restored reach and 14 sites in an unrestored reference reach. Discharge and sediment transport were measured at the downstream end of the restored reach. There were three flooding events during the study, two as annual flood events and a third as a greater than a 5-year flood event. Restoration has returned periodic flood flow to the riparian wetland and provides a mean sedimentation rate of 11.3 mm per year over the study period in the restored reach compared with 1.7 mm per year in an unrestored channelized reach. Sedimentation from the two annual floods was within the normal range for alluvial Coastal Plain rivers. Sediment deposits consisted of over 20% organics, similar to eastern blackwater rivers. The Kissimmee River is unique in North America for its hybrid alluvial/blackwater nature. Fluvial suspended-sediment measurements for the three flood events indicate that a majority of the sediment (70%) was sand, which is important for natural levee construction. Of the total suspended sediment load for the three flood events, 3%–16% was organic and important in floodplain deposition. Sediment yield is similar to low-gradient rivers draining to the Chesapeake Bay and alluvial rivers of the southeastern USA. Continued monitoring should determine whether observed sediment transport and floodplain deposition rates are normal for this river and determine the relationship between historic vegetation community restoration, hydroperiod restoration, and sedimentation.

A Role for Agroforestry in Forest Restoration in the Lower Mississippi Alluvial Valley

Treesearch

Michael G. Dosskey; Gary Bentrup; Michele Schoeneberger

2012-01-01

Agroforestry options are explored for restoring important functions and values of bottomland hardwood (BLH) forests in the lower Mississippi River Alluvial Valley (LMAV). Agroforestry practices can augment the size and quality of BLH habitat, provide corridors between BLH areas, and enable restoration of natural hydrologic patterns and water quality. Agroforestry...

Simulation of interaction between ground water in an alluvial aquifer and surface water in a large braided river

USGS Publications Warehouse

Leake, S.A.; Lilly, M.R.

1995-01-01

The Fairbanks, Alaska, area has many contaminated sites in a shallow alluvial aquifer. A ground-water flow model is being developed using the MODFLOW finite-difference ground-water flow model program with the River Package. The modeled area is discretized in the horizontal dimensions into 118 rows and 158 columns of approximately 150-meter square cells. The fine grid spacing has the advantage of providing needed detail at the contaminated sites and surface-water features that bound the aquifer. However, the fine spacing of cells adds difficulty to simulating interaction between the aquifer and the large, braided Tanana River. In particular, the assignment of a river head is difficult if cells are much smaller than the river width. This was solved by developing a procedure for interpolating and extrapolating river head using a river distance function. Another problem is that future transient simulations would require excessive numbers of input records using the current version of the River Package. The proposed solution to this problem is to modify the River Package to linearly interpolate river head for time steps within each stress period, thereby reducing the number of stress periods required.

Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma

USGS Publications Warehouse

Adams, G.P.; Runkle, Donna; Rea, Alan; Becker, C.J.

1997-01-01

ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of of hydraulic conductivity, recharge, and ground-water level elevation contours for the alluvial and terrace deposits along the North Canadian River from Oklahoma City to Eufaula Lake in east-central Oklahoma. Ground water in 710 square miles of Quaternary-age alluvial and terrace deposits along the North Canadian River is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. The aquifer, composed of alluvial and terrace deposits, consists of sand, silt, clay, and gravel. The aquifer is underlain and in hydraulic connection with the upper zone of the Permian-age Garber-Wellington aquifer and the Pennsylvanian-age Ada-Vamoosa aquifer. Most of the lines in the four digital data sets were digitized from a published ground-water modeling report but portions of the aquifer boundary data set was extracted from published digital geologic data sets. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

Groundwater geochemistry in the Seminole Well Field, Cedar Rapids, Iowa

USGS Publications Warehouse

Boyd, Robert A.

1999-01-01

The City of Cedar Rapids obtains its municipal water supply from four well fields in an alluvial aquifer along the Cedar River in east-central Iowa. Since 1992, the City and the U.S. Geological Survey have cooperatively studied the groundwater-flow system and water chemistry near the well fields. The geochemistry in the alluvial aquifer near the Seminole Well Field was assessed to identify potentially reactive minerals and possible chemical reactions that produce observed changes in water chemistry. Calcite, dolomite, ferrihydrite, quartz, rhodochrosite, and siderite were identified as potentially reactive minerals by calculating saturation indexes. Aluminosiicate minerals including albite, Ca-montmorillonite, gibbsite, illite, K-feldspar, and kaolinite were identified as potentially reactive minerals using hypothetical saturation indexes calculated with an assumed dissolved aluminum concentration of 1 microgram per liter. Balanced chemical equations derived from inverse-modeling techniques were used to assess chemical reactions as precipitation percolates to the water table. Calcite dissolution was predominate, but aluminosilicate weathering, cation exchange, and redox reactions also likely occurred. Microbial-catalyzed redox reactions altered the chemical composition of water infiltrating from the Cedar River into the alluvial aquifer by consuming dissolved oxygen, reducing nitrate, and increasing dissolved iron and manganese concentrations. Nitrate reduction only occurred in relatively shallow (3 to 7 meters below land surface) groundwater near the Cedar River and did not occur in water infiltrating to deeper zones of the alluvial aquifer.

Questa Baseline and Pre-Mining Ground-Water Quality Investigation. 17. Geomorphology of the Red River Valley, Taos County, New Mexico, and Influence on Ground-Water Flow in the Shallow Alluvial Aquifer

USGS Publications Warehouse

Vincent, Kirk R.

2008-01-01

In April 2001, the U.S. Geological Survey (USGS) and the New Mexico Environment Department (NMED) began a cooperative study to infer the pre-mining ground-water chemistry at the Molycorp molybdenum mine site in the Red River Valley of north-central New Mexico. This report is one in a series of reports that can be used to determine pre-mining ground-water conditions at the mine site. Molycorp?s Questa molybdenum mine in the Red River Valley, northern New Mexico, is located near the margin of the Questa caldera in a highly mineralized region. The bedrock of the Taos Range surrounding the Red River is composed of Proterozoic rocks of various types, which are intruded and overlain by Oligocene volcanic rocks associated with the Questa caldera. Locally, these rocks were altered by hydrothermal activity. The alteration zones that contain sulfide minerals are particularly important because they constitute the commercial ore bodies of the region and, where exposed to weathering, form sites of rapid erosion referred to as alteration scars. Over the past thousand years, if not over the entire Holocene, erosion rates were spatially variable. Forested hillslopes eroded at about 0.04 millimeter per year, whereas alteration scars eroded at about 2.7 millimeters per year. The erosion rate of the alteration scars is unusually rapid for naturally occurring sites that have not been disturbed by humans. Watersheds containing large alteration scars delivered more sediment to the Red River Valley than the Red River could remove. Consequently, large debris fans, as much as 80 meters thick, developed within the valley. The geomorphology of the Red River Valley has had several large influences on the hydrology of the shallow alluvial aquifer, and those influences were in effect before the onset of mining within the watershed. Several reaches where alluvial ground water emerges to become Red River streamflow were observed by a tracer dilution study conducted in 2001. The aquifer narrows where erosion-resistant bedrock, which tends to form vertical cliffs, restricts the width of the valley bottom. Although the presence of a shallow bedrock sill, overlain by shallow alluvium, is a plausible cause of ground-water emergence, this cause was not demonstrated in the study area. The water-table gradient can locally decrease in the downstream direction because of changes in the hydraulic properties of the alluvium, and this may be a contributing cause of ground-water emergence. However, at one site (near Cabin Springs), ground-water emergence could not be explained by spatial changes in geometric or hydraulic properties of the aquifer. Furthermore, the available evidence demonstrates that ground water flowing through bedrock fractures or colluvium entered the north side of the alluvial aquifer, and is the cause of ground-water emergence. At that location the alluvial aquifer was already flowing full, causing the excess water to emerge into the stream. An indirect consequence of altered rock in the tributary watersheds is the rapid erosion rate of alteration scars combined with the hydraulic properties of sediments shed from those scars. Where alteration scars are large the debris fans at the mouths of the tributary watersheds substantially encroach into the Red River Valley. At such locations debris-fan materials dominate the width and thickness of the alluvium in the valley and reduce the rate of flow of ground water within the Red River alluvial aquifer. Most sites of groundwater emergence are located immediately upstream from or along the margins of debris fans. A substantial fraction of the ground water approaching a debris fan can emerge to become streamflow. This last observation has three implications. First, very little water can flow the entire length of the study area entirely within the alluvial aquifer because the ground water repeatedly contacts debris-fan sediments over that length. Second, it follows that emerging water containing

Classification of Martian deltas

NASA Technical Reports Server (NTRS)

Dehon, R. A.

1993-01-01

Water-borne sediments in streams are deposited, upon eventual cessation of flow, either as deltas or as alluvial fans or plains. Deltas and alluvial fans share a common characteristic; both may be described as deposition Al plains at the mouth of a river or stream. A delta is formed where a stream or river deposits its sedimentary load into a standing body of water such as an ocean or lake. An alluvial fan is produced where a stream loses capacity by a greatly decreased gradient. A delta has subaerial and subaqueous components, but an alluvial fan is entirely subaerial. In terrestrial conditions, deltas and alluvial fans are reasonably distinct landforms. The juxtaposition of concomitant features composition and internal structure are sufficiently explicit as to avoid any confusion regarding their proper identification on Mars, the recognition of deltas and their distinction from alluvial fans is made difficult by low resolution imaging. Further, although it may be demonstrated that standing bodies of water existed on the surface of Mars, many of these bodies may have existed for extremely short periods of time (a few days to months); hence, distinctive shoreline features were not developed. Thus, in an attempt to derive a Martian classification of deltas, the inclusion of wholly subaerial deposits may be unavoidable. A simple, broad, morphological classification of Martian deltas, primarily on planimetric shape, includes digitate deltas, fan-shaped deltas, and re-entrant deltas. A fourth, somewhat problematical class includes featureless plains at the end of many valley systems.

Using radon to understand parafluvial flows and the changing locations of groundwater inflows in the Avon River, southeast Australia

NASA Astrophysics Data System (ADS)

Cartwright, Ian; Hofmann, Harald

2016-09-01

Understanding the location and magnitude of groundwater inflows to rivers is important for the protection of riverine ecosystems and the management of connected groundwater and surface water systems. This study utilizes 222Rn activities and Cl concentrations in the Avon River, southeast Australia, to determine the distribution of groundwater inflows and to understand the importance of parafluvial flow on the 222Rn budget. The distribution of 222Rn activities and Cl concentrations implies that the Avon River contains alternating gaining and losing reaches. The location of groundwater inflows changed as a result of major floods in 2011-2013 that caused significant movement of the floodplain sediments. The floodplain of the Avon River comprises unconsolidated coarse-grained sediments with numerous point bars and sediment banks through which significant parafluvial flow is likely. The 222Rn activities in the Avon River, which are locally up to 3690 Bq m-3, result from a combination of groundwater inflows and the input of water from the parafluvial zone that has high 222Rn activities due to 222Rn emanation from the alluvial sediments. If the high 222Rn activities were ascribed solely to groundwater inflows, the calculated net groundwater inflows would exceed the measured increase in streamflow along the river by up to 490 % at low streamflows. Uncertainties in the 222Rn activities of groundwater, the gas transfer coefficient, and the degree of hyporheic exchange cannot explain a discrepancy of this magnitude. The proposed model of parafluvial flow envisages that water enters the alluvial sediments in reaches where the river is losing and subsequently re-enters the river in the gaining reaches with flow paths of tens to hundreds of metres. Parafluvial flow is likely to be important in rivers with coarse-grained alluvial sediments on their floodplains and failure to quantify the input of 222Rn from parafluvial flow will result in overestimating groundwater inflows to rivers.

Multiple pathways for woody plant establishment on floodplains at local to regional scales

USGS Publications Warehouse

Cooper, D.J.; Andersen, D.C.; Chimner, Rodney A.

2003-01-01

1. The structure and functioning of riverine ecosystems is dependent upon regional setting and the interplay of hydrologic regime and geomorphologic processes. We used a retrospective analysis to study recruitment along broad, alluvial valley segments (parks) and canyon segments of the unregulated Yampa River and the regulated Green River in the upper Colorado River basin, USA. We precisely aged 811 individuals of Populus deltoides ssp. wislizenii (native) and Tamarix ramosissima (exotic) from 182 wooded patches and determined the elevation and character of the germination surface for each. We used logistic regression to relate recruitment events (presence or absence of cohort) to five flow and two weather parameters.2. Woody plant establishment occurred via multiple pathways at patch, reach and segment scales. Recruitment occurred through establishment on (1) vertically accreting bars in the unregulated alluvial valley, (2) high alluvial floodplain surfaces during rare large flood events, (3) vertically accreting channel margin deposits in canyon pools and eddies, (4) vertically accreting intermittent/abandoned channels, (5) low elevation gravel bars and debris fans in canyons during multi-year droughts, and (6) bars and channels formed prior to flow regulation on the dammed river during controlled flood events.3. The Yampa River's peak flow was rarely included in models estimating the likelihood that recruitment would occur in any year. Flow variability and the interannual pattern of flows, rather than individual large floods, control most establishment.4. Regulation of the Green River flow since 1962 has had different effects on woody vegetation recruitment in canyons and valleys. The current regime mimics drought in a canyon setting, accelerating Tamarix invasion whereas in valleys the ongoing geomorphic adjustment of the channel, combined with reduced flow variability, has nearly eliminated Populus establishment.5. A single year's flow or a particular pattern of flows over a sequence of years, whether natural or man-made, produces different recruitment opportunities in alluvial and canyon reaches, in diverse landforms within a particular river reach, and for Populus and Tamarix. The design of flows to restore riparian ecosystems must consider these multiple pathways and adjust the seasonal timing, magnitude and interannual frequency of flows to match the desired outcome.

On the hyperbolic nature of the equations of alluvial river hydraulics and the equivalence of stable and energy dissipating shocks

NASA Astrophysics Data System (ADS)

Zanraea, D. D. L.; Needham, D. J.

The depth-averaged hydraulic equations augmented with a suitable bed-load sediment transport function form a closed system which governs the one-dimensional flow in an alluvial river or channel. In this paper, it is shown that this system is hyperbolic and yields three families of shock-wave solutions. These are determined to be temporally stable in restricted regions of the (H, F0)-plane, via the Lax shock inequalities. Further, it is demonstrated that this criterion is equivalent to the energy dissipation criterion developed by Needham and Hey (1991).

9. VIEW FROM MANY PARKS CURVE (ON TRAIL RIDGE ROAD) ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. VIEW FROM MANY PARKS CURVE (ON TRAIL RIDGE ROAD) OF HORSESHOE PARK, SHOWING FALL RIVER ROAD FAINTLY AT LEFT AT BASE OF SHEEP MOUNTAIN AND CROSSING ALLUVIAL FAN FROM LAWN LAKE FLOOD. - Fall River Road, Between Estes Park & Fall River Pass, Estes Park, Larimer County, CO

Groundwater resources vulnerability due to melting glaciers in the Talgar alluvian fan, northern Tien-Shan

NASA Astrophysics Data System (ADS)

Saks, Tomas; Timuhins, Andrejs; Sennikovs, Juris; Ibraimov, Vitaliy; Sotnikov, Evgeniy; Salybekova, Valentina; Rahimov, Timur; Popovs, Konrads

2017-04-01

Alluvial fans on the mountain slopes in Central Asia are an important source of the groundwater, due to there capacity of storing large quantities of the fresh groundwater and due to the fact that most urban centres are situated in the mountainous terrain or along mountain slopes. The groundwater resources in the alluvial fans are replenished by the infiltration from the rivers, which drain the mountain catchments and by infiltration from the precipitation, and released on there lower reaches as a series of seasonal springs or infiltrated into the lower lying aquifers. The rivers with there catchments in the mountainous terrain are fed by the precipitation (with the peak in May-June due to snow melt) and glacier melt. The glacier meltwater constitutes up to 90% of the river runoff in July-August, due to peak in glacier melt and low precipitation, providing much needed freshwater for agriculture in the dry season. In this study an attempt to quantify the importance of the glacier meltwater on the groundwater resources through groundwater modelling in the Talgar alluvial fan, Ili-Alatau mountain range has been performed. The results suggest that glacier meltwater is a substantial portion of the groundwater resources in the Talgar alluvial fan, with up to 30m drop of the groundwater level, if the glaciers disappear, endangering existing groundwater supply. The transient simulations suggest that disappearance of the glaciers and highly variable annual precipitation would result in highly fluctuating groundwater levels, as well as disappearance of most of the springs at the foot of the alluvial fan. These results are especially relevant for the northern Tien-Shan, where glaciers have been rapidly retreating over last 50 years, and some of the glaciers could disappear in next decades.

Export of earthquake-triggered landslides in active mountain ranges: insights from 2D morphodynamic modelling.

NASA Astrophysics Data System (ADS)

Croissant, Thomas; Lague, Dimitri; Davy, Philippe; Steer, Philippe

2016-04-01

In active mountain ranges, large earthquakes (Mw > 5-6) trigger numerous landslides that impact river dynamics. These landslides bring local and sudden sediment piles that will be eroded and transported along the river network causing downstream changes in river geometry, transport capacity and erosion efficiency. The progressive removal of landslide materials has implications for downstream hazards management and also for understanding landscape dynamics at the timescale of the seismic cycle. The export time of landslide-derived sediments after large-magnitude earthquakes has been studied from suspended load measurements but a full understanding of the total process, including the coupling between sediment transfer and channel geometry change, still remains an issue. Note that the transport of small sediment pulses has been studied in the context of river restoration, but the magnitude of sediment pulses generated by landslides may make the problem different. Here, we study the export of large volumes (>106 m3) of sediments with the 2D hydro-morphodynamic model, Eros. This model uses a new hydrodynamic module that resolves a reduced form of the Saint-Venant equations with a particle method. It is coupled with a sediment transport and lateral and vertical erosion model. Eros accounts for the complex retroactions between sediment transport and fluvial geometry, with a stochastic description of the floods experienced by the river. Moreover, it is able to reproduce several features deemed necessary to study the evacuation of large sediment pulses, such as river regime modification (single-thread to multi-thread), river avulsion and aggradation, floods and bank erosion. Using a synthetic and simple topography we first present how granulometry, landslide volume and geometry, channel slope and flood frequency influence 1) the dominance of pulse advection vs. diffusion during its evacuation, 2) the pulse export time and 3) the remaining volume of sediment in the catchment. The model is then applied to a high resolution (5-10 m) digital elevation model of the Poerua catchment in New Zealand which has been impacted by the effect of a large landslide during the last 15 years. We investigate several plausible Alpine Faults earthquake scenarios to study the propagation of the sediment along a complex river network. We characterize and quantify the sediment pulse export time and mechanism for this river configuration and show its impact on the alluvial plain evolution. Our findings have strong implications for the understanding of aggradation rates and the temporal persistence of induced hazards in the alluvial plain as well as of sediment transfers in active mountain belts.

A philosophy of rivers: Equilibrium states, channel evolution, teleomatic change and least action principle

NASA Astrophysics Data System (ADS)

Nanson, Gerald C.; Huang, He Qing

2018-02-01

Until recently no universal agreement as to a philosophical or scientific methodological framework has been proposed to guide the study of fluvial geomorphology. An understanding of river form and process requires an understanding of the principles that govern the behaviour and evolution of alluvial rivers at the most fundamental level. To date, the investigations of such principles have followed four approaches: develop qualitative unifying theories that are usually untested; collect and examine data visually and statistically to define semi-quantitative relationships among variables; apply Newtonian theoretical and empirical mechanics in a reductionist manner; resolve the primary flow equations theoretically by assuming maximum or minimum outputs. Here we recommend not a fifth but an overarching philosophy to embrace all four: clarifying and formalising an understanding of the evolution of river channels and iterative directional changes in the context of least action principle (LAP), the theoretical basis of variational mechanics. LAP is exemplified in rivers in the form of maximum flow efficiency (MFE). A sophisticated understanding of evolution in its broadest sense is essential to understand how rivers adjust towards an optimum state rather than towards some other. Because rivers, as dynamic contemporary systems, flow in valleys that are commonly historical landforms and often tectonically determined, we propose that most of the world's alluvial rivers are over-powered for the work they must do. To remain stable they commonly evolve to expend surplus energy via a variety of dynamic equilibrium forms that will further adjust, where possible, to maximise their stability as much less common MFE forms in stationary equilibrium. This paper: 1. Shows that the theory of evolution is derived from, and applicable to, both the physical and biological sciences; 2. Focusses the development of theory in geomorphology on the development of equilibrium theory; 3. Proposes that river channels, like organisms, evolve teleomatically (progression towards an end-state by following natural laws) and iteratively (one stage forming the basis for the next) towards an optimal end-state; 4. Describes LAP as the methodological basis for understanding the self-adjustment alluvial channels towards MFE. 5. Acknowledges that whereas river channels that form within their unmodified alluvium evolve into optimal minimum-energy systems, exogenic variables, such as riparian or aquatic vegetation, can cause significant variations in resultant river-styles. We specifically attempt to address Luna Leopold's lament in 1994 that no clearly expressed philosophy explains the remarkable self-adjustment of alluvial channels.

Advance, Retreat, and Halt of Abrupt Gravel-Sand Transitions in Alluvial Rivers

NASA Astrophysics Data System (ADS)

Blom, Astrid; Chavarrías, Víctor; Ferguson, Robert I.; Viparelli, Enrica

2017-10-01

Downstream fining of bed sediment in alluvial rivers is usually gradual, but often an abrupt decrease in characteristic grain size occurs from about 10 to 1 mm, i.e., a gravel-sand transition (GST) or gravel front. Here we present an analytical model of GST migration that explicitly accounts for gravel and sand transport and deposition in the gravel reach, sea level change, subsidence, and delta progradation. The model shows that even a limited gravel supply to a sand bed reach induces progradation of a gravel wedge and predicts the circumstances required for the gravel front to advance, retreat, and halt. Predicted modern GST migration rates agree well with measured data at Allt Dubhaig and the Fraser River, and the model qualitatively captures the behavior of other documented gravel fronts. The analysis shows that sea level change, subsidence, and delta progradation have a significant impact on the GST position in lowland rivers.

Effect of seasonal flooding cycle on litterfall production in alluvial rainforest on the middle Xingu River (Amazon basin, Brazil).

PubMed

Camargo, M; Giarrizzo, T; Jesus, A J S

2015-08-01

The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperança and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems.

Composition, potential old growth, fragmentation, and ownership of Mississippi Alluvial Valley bottomland hardwoods: a regional assessment of historic change

Treesearch

Victor A. Rudis

2001-01-01

Abstract-Recent Mississippi River Alluvial Valley (MAV) bottomland hardwood forest surveys revealed a larger proportion of intermittent flood zone (inundated 1 to 2 months), early successional (primarily hackberry-elm-ash), and permanent flood zone (inundated > 6 months annually, primarily baldcypress-water tupelo) community types than in the...

Afforestation of marginal agricultural land in the lower Mississippi River Alluvial Valley, U.S.A.

Treesearch

John A. Stanturf; Callie J. Schweitzer; Emile S. Gardiner

1998-01-01

Afforestation of marginal agricultural land in the Lower Mississippi Alluvial Valley (LMAV) relies on native species, planted mostly in single-species plantations. Hard mast species such as oak and pecan are favored for their value to wildlife, especially on public land. Successful afforestation requires an understanding of site variation within floodplains and...

Characterization and simulation of ground-water flow in the Kansas River Valley at Fort Riley, Kansas, 1990-98

USGS Publications Warehouse

Myers, Nathan C.

2000-01-01

Hydrologic data and a ground-water flow model were used to characterize ground-water flow in the Kansas River alluvial aquifer at Fort Riley in northeast Kansas. The ground-water flow model was developed as a tool to project ground-water flow and potential contaminant-transport paths in the alluvial aquifer on the basis of past hydrologic conditions. The model also was used to estimate historical and hypothetical ground-water flow paths with respect to a private- and several public-supply wells. The ground-water flow model area extends from the Smoky Hill and Republican Rivers downstream to about 2.5 miles downstream from the city of Ogden. The Kansas River Valley has low relief and, except for the area within the Fort Riley Military Reservation, is used primarily for crop production. Sedimentary deposits in the Kansas River Valley, formed after the ancestral Kansas River eroded into bedrock, primarily are alluvial sediment deposited by the river during Quaternary time. The alluvial sediment consists of as much as about 75 feet of poorly sorted, coarse-to-fine sand, silt, and clay, 55 feet of which can be saturated with ground water. The alluvial aquifer is unconfined and is bounded on the sides and bottom by Permian-age shale and limestone bedrock. Hydrologic data indicate that ground water in the Kansas River Valley generally flows in a downstream direction, but flow direction can be quite variable near the Kansas River due to changes in river stage. Ground-water-level changes caused by infiltration of precipitation are difficult to detect because they are masked by larger changes caused by fluctuation in Kansas River stage. Ratios of strontium isotopes Sr87 and Sr86 in water collected from wells in the Camp Funston Area indicate that the ground water along the northern valley wall originates, in part, from upland areas north of the river valley. Water from Threemile Creek, which flows out of the uplands north of the river valley, had Sr87:Sr86 ratios similar to those in ground water from wells in the northern Camp Funston Area. In addition, comparison of observed water levels from wells CF90-06, CF97-101, and CF97-401 in the Camp Funston Area and ground-water levels simulated for these wells using floodwave-response analysis indicates that ground-water inflow from bedrock is a hydraulic stress that, in addition to the changing stage in the Kansas River, acts on the aquifer. This hydraulic stress seems to be located near the northern valley wall because the effect of this stress is greater for well CF97-101, which is the well closest to the valley wall. Ground-water flow was simulated using a modular, three-dimensional, finite-difference ground-water flow model (MODFLOW). Particle tracking, used to visualize ground-water flow paths in the alluvial aquifer, was accomplished using MODPATH. Forward-in-time particle tracking indicated that, in general, particles released near the Kansas River followed much more variable paths than particles released near the valley wall. Although particle tracking does not simulate solute transport, this increased path variability indicates that, near the river, ground-water contaminants could follow many possible paths towards the river, whereas more distant from the river, ground-water contaminants likely would follow a narrower corridor. Particle tracks in the Camp Funston Area indicate that, for the 1990-98 simulation period, contaminants from the ground-water study sites in the Camp Funston Area would be unlikely to move into the vicinity of Ogden's supply wells. Backward-in-time particle tracking indicated that the flow-path and recharge areas for model cells corresponding to Ogden's supply wells lie near the northern valley wall and extend into the northern Camp Funston Area. The flow-path and recharge areas for model cells corresponding to Morris County Rural Water District wells lie within Clarks Creek Valley and probably extend outside the model area. Three hypothetical simulations, i

Geophysical Characterization of the Quaternary-Cretaceous Contact Using Surface Resistivity Methods in Franklin and Webster Counties, South-Central Nebraska

USGS Publications Warehouse

Teeple, Andrew; Kress, Wade H.; Cannia, James C.; Ball, Lyndsay B.

2009-01-01

To help manage and understand the Platte River system in Nebraska, the Platte River Cooperative Hydrology Study (COHYST), a group of state and local governmental agencies, developed a regional ground-water model. The southern boundary of this model lies along the Republican River, where an area with insufficient geologic data immediately north of the Republican River led to problems in the conceptualization of the simulated flow system and to potential problems with calibration of the simulation. Geologic descriptions from a group of test holes drilled in south-central Nebraska during 2001 and 2002 indicated a possible hydrologic disconnection between the Quaternary-age alluvial deposits in the uplands and those in the Republican River lowland. This disconnection was observed near a topographic high in the Cretaceous-age Niobrara Formation, which is the local bedrock. In 2003, the U.S. Geological Survey, in cooperation with the COHYST, collected surface geophysical data near these test holes to better define this discontinuity. Two-dimensional imaging methods for direct-current resistivity and capacitively coupled resistivity were used to define the subsurface distribution of resistivity along several county roads near Riverton and Inavale, Nebraska. The relation between the subsurface distribution of resistivity and geology was defined by comparing existing geologic descriptions of test holes to surface-geophysical resistivity data along two profiles and using the information gained from these comparisons to interpret the remaining four profiles. In all of the resistivity profile sections, there was generally a three-layer subsurface interpretation, with a resistor located between two conductors. Further comparison of geologic data with the geophysical data and with surficial features was used to identify a topographic high in the Niobrara Formation near the Franklin Canal which was coincident with a resistivity high. Electrical properties of the Niobrara Formation made accurate interpretation of the resistivity profile sections difficult and less confident because of similar resistivity of this formation and that of the coarser-grained sediment of the Quaternary-age deposits. However, distinct conductive features were identified within the resistivity profile sections that aided in delineating the contact between the resistive Quaternary-age deposits and the resistive Niobrara Formation. Using this information, an interpretive boundary was drawn on the resistivity profile sections to represent the contact between the Quaternary-age alluvial deposits and the Cretaceous-age Niobrara Formation. A digital elevation model (DEM) of the top of the Niobrara Formation was constructed using the altitudes from the interpreted contact lines. This DEM showed that the general trend of top of the Niobrara Formation dips to the southeast. At the north edge of the study site, the Niobrara Formation topographic high trends east-west with an altitude range of 559 meters in the west to 543 meters in the east. Based on the land-surface elevation and the Niobrara Formation DEM, the estimated thickness of the Quaternary-age alluvial deposits throughout the study area was mapped and showed a thinning of the Quaternary-age alluvial deposits to the north, approximately where the topographic high of the Niobrara Formation is located. This topographic high in the Niobrara Formation has the potential to act as a barrier to ground-water flow from the uplands alluvial aquifer to the Republican River alluvial aquifer as shown in the resistivity profile sections. The Quaternary-age alluvial deposits in the uplands and those in the Republican River Valley are not fully represented as disconnected because it is possible that there are ground-water flow paths that were not mapped during this study.

Near-decadal changes in nitrate and pesticide concentrations in the South Platte River alluvial aquifer, 1993-2004

USGS Publications Warehouse

Paschke, S.S.; Schaffrath, K.R.; Mashbum, S.L.

2008-01-01

The lower South Platte River basin of Colorado and Nebraska is an area of intense agriculture supported by surface-water diversions from the river and ground-water pumping from a valley-fill alluvial aquifer. Two well networks consisting of 45 wells installed in the South Platte alluvial aquifer were sampled in the early 1990s and again in the early 2000s to examine near-decadal ground-water quality changes in irrigated agricultural areas. Ground-water age generally increases and dissolved-oxygen content decreases with distance along flow paths and with depdi below the water table, and denitrification is an important natural mitigation mechanism for nitrate in downgradient areas. Ground-water travel time from upland areas to the river ranges from 12 to 31 yr on the basis of apparent ground-water ages. Ground-water nitrate concentrations for agricultural land-use wells increased significantly for oxidized samples over the decade, and nitrogen isotope ratios for oxidized samples indicate synthetic fertilizer as the predominant nitrate source. Ground-water concentrations of atrazine, DEA, and prometon decreased significandy. The decrease in pesticide concentrations and a significant increase in the ratio of DEA to atrazine suggest decreases in pesticide concentrations are likely caused by local decreases in application rates and/or degradation processes and that atrazine degradation is promoted by oxidizing conditions. The difference between results for oxidizing and nitrate-reducing conditions indicates redox state is an important variable to consider when evaluating ground-water quality trends for redox-sensitive constituents such as nitrate and pesticides in the South Platte alluvial aquifer. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Modeling and measuring the relationships between sediment transport processes, alluvial bedforms and channel-scale morphodynamics in sandy braided rivers.

NASA Astrophysics Data System (ADS)

Nicholas, A. P.; Ashworth, P. J.; Best, J.; Lane, S. N.; Parsons, D. R.; Sambrook Smith, G.; Simpson, C.; Strick, R. J. P.; Unsworth, C. A.

2017-12-01

Recent years have seen significant advances in the development and application of morphodynamic models to simulate river evolution. Despite this progress, significant challenges remain to be overcome before such models can provide realistic simulations of river response to environmental change, or be used to determine the controls on alluvial channel patterns and deposits with confidence. This impasse reflects a wide range of factors, not least the fact that many of the processes that control river behaviour operate at spatial scales that cannot be resolved by such models. For example, sand-bed rivers are characterised by multiple scales of topography (e.g., dunes, bars, channels), the finest of which must often by parameterized, rather than represented explicitly in morphodynamic models. We examine these issues using a combination of numerical modeling and field observations. High-resolution aerial imagery and Digital Elevation Models obtained for the sandy braided South Saskatchewan River in Canada are used to quantify dune, bar and channel morphology and their response to changing flow discharge. Numerical simulations are carried out using an existing morphodynamic model based on the 2D shallow water equations, coupled with new parameterisations of the evolution and influence of alluvial bedforms. We quantify the spatial patterns of sediment flux using repeat images of dune migration and bar evolution. These data are used to evaluate model predictions of sediment transport and morphological change, and to assess the degree to which model performance is controlled by the parametrization of roughness and sediment transport phenomena linked to subgrid-scale bedforms (dunes). The capacity of such models to replicate the characteristic multi-scale morphology of bars in sand-bed rivers, and the contrasting morphodynamic signatures of braiding during low and high flow conditions, is also assessed.

Niche construction within riparian corridors. Part I: Exploring biogeomorphic feedback windows of three pioneer riparian species (Allier River, France)

NASA Astrophysics Data System (ADS)

Hortobágyi, Borbála; Corenblit, Dov; Steiger, Johannes; Peiry, Jean-Luc

2018-03-01

Within riparian corridors, biotic-abiotic feedback mechanisms occur between woody vegetation strongly influenced by hydrogeomorphic constraints (e.g., sediment transport and deposition, shear stress, hydrological variability), fluvial landforms, and morphodynamics, which in turn are modulated by the established vegetation. During field investigations in spring 2015, we studied 16 alluvial bars (e.g., point and lateral bars) within the dynamic riparian corridor of the Allier River (France) to assess the aptitude of three pioneer riparian Salicaceae species (Populus nigra L., Salix purpurea L., and Salix alba L.) to establish and act as ecosystem engineers by trapping sediment and constructing fluvial landforms. Our aim is to empirically identify the preferential establishment area (EA; i.e., the local areas where species become established) and the preferential biogeomorphic feedback window (BFW; i.e., where and to what extent the species and geomorphology interact) of these three species on alluvial bars within a 20-km-long river reach. Our results show that the EA and BFW of all three species vary significantly along the longitudinal profile, i.e., upstream-downstream exposure on the alluvial bars, as well as transversally, i.e., the main hydrological connectivity gradient from the river channel toward the floodplain. In the present-day context of the Allier River, P. nigra is the most abundant species, appearing to act as the main engineer species affecting landform dynamics at the bar scale; S. purpurea is established and acts as an ecosystem engineer at locations on alluvial bars that are most exposed to hydrosedimentary flow dynamics, while S. alba is established on the bar tail close to secondary channels and affects the geomorphology in mixed patches along with P. nigra. Our study highlights the role of functional trait diversity of riparian engineer species in controlling the extent of fluvial landform construction along geomorphic gradients within riparian corridors exposed to frequent hydrogeomorphic disturbances.

Rivers turned to rock: Late Quaternary alluvial induration influencing the behaviour and morphology of an anabranching river in the Australian monsoon tropics

NASA Astrophysics Data System (ADS)

Nanson, Gerald C.; Jones, Brian G.; Price, David M.; Pietsch, Timothy J.

2005-09-01

Late Quaternary alluvial induration has greatly influenced contemporary channel morphology on the anabranching Gilbert River in the monsoon tropics of the Gulf of Carpentaria. The Gilbert, one of a number of rivers in this region, has contributed to an extensive system of coalescing low-gradient and partly indurated riverine plains. Extensive channel sands were deposited by enhanced flow conditions during marine oxygen isotope (OI) Stage 5. Subsequent flow declined, probably associated with increased aridity, however, enhanced runoff recurred again in OI Stages 4-3 (˜65-50 ka). Aridity then capped these plains with 4-7 m of mud. A widespread network of sandy distributary channels was incised into this muddy surface from sometime after the Last Glacial Maximum (LGM) to the mid Holocene during a fluvial episode more active than the present but less so than those of OI Stages 5 and 3. This network is still partly active but with channel avulsion and abandonment now occurring largely proximal to the main Gilbert flow path. A tropical climate and reactive catchment lithology have enhanced chemical weathering and lithification of alluvium along the river resulting in the formation of small rapids, waterfalls and inset gorges, features characteristic more of bedrock than alluvial systems. Thermoluminescence (TL) and comparative optically stimulated luminescence (OSL) ages of the sediments are presented along with U/Th ages of pedogenic calcrete and Fe/Mn oxyhydroxide/ oxide accumulations. They show that calcrete precipitated during the Late Quaternary at times similar to those that favoured ferricrete formation, possibly because of an alternating wet-dry climate. Intense chemical alteration of the alluvium leading to induration appears to have prevailed for much of the Late Quaternary but, probably due to exceptional dryness, not during the LGM. The result has been restricted channel migration and a reduced capacity for the channel to adjust and accommodate sudden changes in bedload. Consequent avulsions have caused local stream powers to increase by an order of magnitude, inducing knickpoint erosion, local incision and the sudden influx of additional bedload that has triggered further avulsions. The Gilbert River, while less energetic than its Pleistocene ancestors, is clearly an avulsive system, and emphasizes the importance in some tropical rivers of alluvial induration for reinforcing the banks, generating nickpoints, reworking sediment and thereby developing and maintaining an indurated and anabranching river style.

Long-term measurements of agronomic crop irrigation in the Mississippi Delta portion of the Lower Mississippi River Valley

USDA-ARS?s Scientific Manuscript database

With over 4 million ha irrigated cropland, the Lower Mississippi River Valley (LMRV) is a highly productive agricultural region where irrigation practices are similar and the Mississippi River Valley alluvial aquifer (MRVA) is a primary source of on-demand irrigation. Owing to agricultural exports, ...

GROUNDWATER-SURFACE WATER EXCHANGE AND IMPLICATIONS FOR LARGE RIVER RESTORATION

EPA Science Inventory

Movement of river water into and out of high-porosity alluvial deposits can have an important influence on surface water quality and aquatic habitat. In our study of a 60-km reach of the Willamette River in Oregon, USA, we: 1) used tracers to estimate the rate of exchange betw...

Lithology, hydrologic characteristics, and water quality of the Arkansas River Valley alluvial aquifer in the vicinity of Van Buren, Arkansas

USGS Publications Warehouse

Kresse, Timothy M.; Westerman, Drew A.; Hart, Rheannon M.

2015-01-01

The hydrologic and geochemical data gathered for this study provide a qualitative assessment of the potential of the Arkansas River Valley alluvial aquifer as a source of public water supply in the Van Buren area. Results indicate minimal influx of water from the Arkansas River, and recharge to the aquifer appears to be dominantly by infiltration of precipitation through overlying alluvium. If vertical wells are used as a source of public water supply, then several wells will have to be used in combination at relatively low pumping rates and placed in areas with a greater percent sand. Use of a horizontal well configuration near the river to increase production may depend on infiltration of river water to supplement water removed from storage, especially where areas of lower permeability sediments might be encountered within the surrounding alluvium. If a poor hydraulic connection exists between the river and the alluvium, as indicated by this study, then production will depend on ample precipitation and recharge throughout the year and groundwater storage sufficient to prevent declining water levels where pumping rates exceed recharge.

Organic matter and modeling redox reactions during river bank filtration in an alluvial aquifer of the Lot River, France.

PubMed

Kedziorek, Monika A M; Geoffriau, Stephane; Bourg, Alain C M

2008-04-15

A 3 year study of the infiltration of Lot River water into a well field located in an adjacent gravel and clay alluvial aquifer was conducted to assess the importance of organic matter regarding the redox processes which influence groundwater quality in a positive (denitrification) or negative (Mn dissolution) manner. Chloride was used to quantify the mixing of river water with groundwater. According to modeling with PHREEQC, the biodegradation of the infiltrated dissolved organic carbon (DOCi) is not sufficient to explain the observed consequences of the redox reactions (dissolved O2 depletion, denitrification, Mn dissolution). Another electron donor source must therefore be involved: we propose solid organic carbon (SOC) as a likely candidate, if made available for degradation by prior hydrolysis. Its contribution to redox reactions could be significant (30-80% of the total organic carbon consumed by redox reactions during river bank filtration). We show here also that even though the first few meters of infiltration are highly reactive, significant redox reactions can take place further in the aquifer, possibly affecting groundwater quality away from the river bank.

Cosmogenic 3He age estimates of Plio-Pleistocene alluvial-fan surfaces in the Lower Colorado River Corridor, Arizona, USA

NASA Astrophysics Data System (ADS)

Fenton, Cassandra R.; Pelletier, Jon D.

2013-01-01

Plio-Pleistocene deposits of the Lower Colorado River (LCR) and tributary alluvial fans emanating from the Black Mountains near Golden Shores, Arizona record six cycles of Late Cenozoic aggradation and incision of the LCR and its adjacent alluvial fans. Cosmogenic 3He (3Hec) ages of basalt boulders on fan terraces yield age ranges of: 3.3-2.2 Ma, 2.2-1.1 Ma, 1.1 Ma to 110 ka, < 350 ka, < 150 ka, and < 63 ka. T1 and Q1 fans are especially significant, because they overlie Bullhead Alluvium, i.e. the first alluvial deposit of the LCR since its inception ca. 4.2 Ma. 3Hec data suggest that the LCR began downcutting into the Bullhead Alluvium as early as 3.3 Ma and as late as 2.2 Ma. Younger Q2a to Q4 fans very broadly correlate in number and age with alluvial terraces elsewhere in the southwestern USA. Large uncertainties in 3Hec ages preclude a temporal link between the genesis of the Black Mountain fans and specific climate transitions. Fan-terrace morphology and the absence of significant Plio-Quaternary faulting in the area, however, indicate regional, episodic increases in sediment supply, and that climate change has possibly played a role in Late Cenozoic piedmont and valley-floor aggradation in the LCR valley.

The recharge process in alluvial strip aquifers in arid Namibia and implication for artificial recharge

NASA Astrophysics Data System (ADS)

Sarma, Diganta; Xu, Yongxin

2017-01-01

Alluvial strip aquifers associated with ephemeral rivers are important groundwater supply sources that sustain numerous settlements and ecological systems in arid Namibia. More than 70 % of the population in the nation's western and southern regions depend on alluvial aquifers associated with ephemeral rivers. Under natural conditions, recharge occurs through infiltration during flood events. Due to the characteristic spatial and temporal variability of rainfall in arid regions, recharge is irregular making the aquifers challenging to manage sustainably and they are often overexploited. This condition is likely to become more acute with increasing water demand and climate change, and artificial recharge has been projected as the apparent means of increasing reliability of supply. The article explores, through a case study and numerical simulation, the processes controlling infiltration, significance of surface water and groundwater losses, and possible artificial recharge options. It is concluded that recharge processes in arid alluvial aquifers differ significantly from those processes in subhumid systems and viability of artificial recharge requires assessment through an understanding of the natural recharge process and losses from the aquifer. It is also established that in arid-region catchments, infiltration through the streambed occurs at rates dependent on factors such as antecedent conditions, flow rate, flow duration, channel morphology, and sediment texture and composition. The study provides an important reference for sustainable management of alluvial aquifer systems in similar regions.

Characterization of geomorphic units in the alluvial valleys and channels of Gulf Coastal Plain rivers in Texas, with examples from the Brazos, Sabine, and Trinity Rivers, 2010

USGS Publications Warehouse

Coffman, David K.; Malstaff, Greg; Heitmuller, Franklin T.

2011-01-01

The U.S. Geological Survey, in cooperation with the Texas Water Development Board, described and characterized examples of geomorphic units within the channels and alluvial valleys of Texas Gulf Coastal Plain rivers using a geomorphic unit classification scale that differentiates geomorphic units on the basis of their location either outside or inside the river channel. The geomorphic properties of a river system determine the distribution and type of potential habitat both within and adjacent to the channel. This report characterizes the geomorphic units contained in the river channels and alluvial valleys of Texas Gulf Coastal Plain rivers in the context of the River Styles framework. This report is intended to help Texas Instream Flow Program practitioners, river managers, ecologists and biologists, and others interested in the geomorphology and the physical processes of the rivers of the Texas Gulf Coastal Plain (1) gain insights into how geomorphic units develop and adjust spatially and temporally, and (2) be able to recognize common geomorphic units from the examples cataloged in this report. Recent aerial imagery (high-resolution digital orthoimagery) collected in 2008 and 2009 were inspected by using geographic information system software to identify representative examples of the types of geomorphic units that occurred in the study area. Geomorphic units outside the channels of Texas Gulf Coastal Plain rivers are called \\"valley geomorphic units\\" in this report. Valley geomorphic units for the Texas Gulf Coastal Plain rivers described in this report are terraces, flood plains, crevasses and crevasse splays, flood-plain depressions, tie channels, tributaries, paleochannels, anabranches, distributaries, natural levees, neck cutoffs, oxbow lakes, and constructed channels. Channel geomorphic units occur in the river channel and are subject to frequent stresses associated with flowing water and sediment transport; they adjust (change) relatively quickly in response to short-term variations in flow. Channel geomorphic units described in this report are channel banks, benches and ledges, bank failures, point bars, cross-bar channels, channel bars, exposed bedrock, pools, runs, and crossovers.

Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

PubMed

Malison, Rachel L; Kuzishchin, Kirill V; Stanford, Jack A

2016-01-01

Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3-12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99-1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically could produce 2× the biomass (between June-August, 1,174 vs. 667 kg) and rear 3× the number of salmon (370,000 vs. 140,000) compared to the existing condition with dams present. The highly productive Kol river produces an order of magnitude more salmon biomass and rears 40× the individuals compared to the Kwethluk. If beavers were introduced to the Kol River, we estimate that off-channel habitats would produce half as much biomass (2,705 vs. 5,404 kg) and 3× fewer individuals (1,482,346 vs. 4,856,956) owing to conversion of inter-connected, productive springbrooks into inaccessible pond complexes. We concluded that beaver dams may limit the total amount of floodplain habitat available for salmon rearing in the Kwethluk river and that the introduction of beavers to the Kol river could be detrimental to salmon populations. The introduction of beavers to other large alluvial rivers like those found in Kamchatka could have negative consequences for salmon production.

Do beaver dams reduce habitat connectivity and salmon productivity in expansive river floodplains?

PubMed Central

Kuzishchin, Kirill V.; Stanford, Jack A.

2016-01-01

Beaver have expanded in their native habitats throughout the northern hemisphere in recent decades following reductions in trapping and reintroduction efforts. Beaver have the potential to strongly influence salmon populations in the side channels of large alluvial rivers by building dams that create pond complexes. Pond habitat may improve salmon productivity or the presence of dams may reduce productivity if dams limit habitat connectivity and inhibit fish passage. Our intent in this paper is to contrast the habitat use and production of juvenile salmon on expansive floodplains of two geomorphically similar salmon rivers: the Kol River in Kamchatka, Russia (no beavers) and the Kwethluk River in Alaska (abundant beavers), and thereby provide a case study on how beavers may influence salmonids in large floodplain rivers. We examined important rearing habitats in each floodplain, including springbrooks, beaver ponds, beaver-influenced springbrooks, and shallow shorelines of the river channel. Juvenile coho salmon dominated fish assemblages in all habitats in both rivers but other species were present. Salmon density was similar in all habitat types in the Kol, but in the Kwethluk coho and Chinook densities were 3–12× lower in mid- and late-successional beaver ponds than in springbrook and main channel habitats. In the Kol, coho condition (length: weight ratios) was similar among habitats, but Chinook condition was highest in orthofluvial springbrooks. In the Kwethluk, Chinook condition was similar among habitats, but coho condition was lowest in main channel versus other habitats (0.89 vs. 0.99–1.10). Densities of juvenile salmon were extremely low in beaver ponds located behind numerous dams in the orthofluvial zone of the Kwethluk River floodplain, whereas juvenile salmon were abundant in habitats throughout the entire floodplain in the Kol River. If beavers were not present on the Kwethluk, floodplain habitats would be fully interconnected and theoretically could produce 2× the biomass (between June–August, 1,174 vs. 667 kg) and rear 3× the number of salmon (370,000 vs. 140,000) compared to the existing condition with dams present. The highly productive Kol river produces an order of magnitude more salmon biomass and rears 40× the individuals compared to the Kwethluk. If beavers were introduced to the Kol River, we estimate that off-channel habitats would produce half as much biomass (2,705 vs. 5,404 kg) and 3× fewer individuals (1,482,346 vs. 4,856,956) owing to conversion of inter-connected, productive springbrooks into inaccessible pond complexes. We concluded that beaver dams may limit the total amount of floodplain habitat available for salmon rearing in the Kwethluk river and that the introduction of beavers to the Kol river could be detrimental to salmon populations. The introduction of beavers to other large alluvial rivers like those found in Kamchatka could have negative consequences for salmon production. PMID:27635357

Topographic and hydraulic controls over alluviation on a bedrock template

NASA Astrophysics Data System (ADS)

Milan, David; Heritage, George; Entwistle, Neil; Tooth, Stephen

2017-04-01

Bedrock-alluvial anastomosed channels found in dryland rivers are characterised by an over-wide channel cut into the host rock containing a network of interconnecting bedrock sub-channels separated by bedrock influenced interfluve areas. Whilst the channels remain largely free of sediment the interfluves display varying levels of alluviation ranging from bare rock, sand sheets and silt drapes through to consolidated bedrock core bars, islands and lateral deposits. Examination of the sedimentary units associated with the bedrock anastomosed reaches of the Sabie river in the Kruger National Park, South Africa reveal a repeating sequence of coarse sand / fine gravel grading through to silt representing successive flood related depositional units. Unit development in relation to the bedrock template was investigated using pre-flood aerial imagery of bedrock core bar locations and post flood LiDAR data of bedrock anastomosed sites stripped during the 2000 and 2012 extreme flood events. This revealed a propensity for bar development associated with bedrock hollows disconnected from the principal high-energy sub-channels. 2-D morpho-dynamic modelling was used to further investigate spatial patterns of deposition over the bedrock template. Although topographic lows displayed mid-range velocities during peak flow events, these are likely to be preferential routing areas, with sediments stalling in low energy areas on the falling limb of floods. It is also likely that vegetation development plays a fundamental role in the development of alluviated zones, through increasing strength of alluvial units and capturing new sediments. With these results in mind we present a conceptual model for the development of bedrock-core bars, the fundamental unit in bedrock-alluvial anastomosed channels.

Development of a black willow improvement program for biomass production in the Lower Mississippi River Alluvial Valley

Treesearch

Randell J. Rousseau; Emile S. Gardiner; Theodor D. Leininger

2012-01-01

Black willow (Salix nigra Marsh.) has the potential to be a significant feedstock source for bioenergy and biofuels production in the Lower Mississippi Alluvial Valley (LMAV). This potential is based on a number of primary factors including rapid growth, ease of vegetative propagation, excellent rooting, and the ability to regenerate from coppice...

Publications - PIR 2003-1 | Alaska Division of Geological & Geophysical

Science.gov Websites

, Alluvial facies and paleosols in the Cretaceous Nanushuk formation, Kanayut River, North Slope, Alaska Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS PIR 2003-1 Publication Details Title: Alluvial facies and paleosols in the Cretaceous

Multiconfiguration electromagnetic induction survey for paleochannel internal structure imaging: a case study in the alluvial plain of the River Seine, France

NASA Astrophysics Data System (ADS)

Rejiba, Fayçal; Schamper, Cyril; Chevalier, Antoine; Deleplancque, Benoit; Hovhannissian, Gaghik; Thiesson, Julien; Weill, Pierre

2018-01-01

The La Bassée floodplain area is a large groundwater reservoir controlling most of the water exchanged between local aquifers and hydrographic networks within the Seine River basin (France). Preferential flows depend essentially on the heterogeneity of alluvial plain infilling, whose characteristics are strongly influenced by the presence of mud plugs (paleomeander clayey infilling). These mud plugs strongly contrast with the coarse sand material that composes most of the alluvial plain, and can create permeability barriers to groundwater flows. A detailed knowledge of the global and internal geometry of such paleomeanders can thus lead to a comprehensive understanding of the long-term hydrogeological processes of the alluvial plain. A geophysical survey based on the use of electromagnetic induction was performed on a wide paleomeander, situated close to the city of Nogent-sur-Seine in France. In the present study we assess the advantages of combining several spatial offsets, together with both vertical and horizontal dipole orientations (six apparent conductivities), thereby mapping not only the spatial distribution of the paleomeander derived from lidar data but also its vertical extent and internal variability.

Holocene alluvial stratigraphy and response to climate change in the Roaring River valley, Front Range, Colorado, USA

USGS Publications Warehouse

Madole, Richard F.

2012-01-01

Stratigraphic analyses and radiocarbon geochronology of alluvial deposits exposed along the Roaring River, Colorado, lead to three principal conclusions: (1) the opinion that stream channels in the higher parts of the Front Range are relics of the Pleistocene and nonalluvial under the present climate, as argued in a water-rights trial USA v. Colorado, is untenable, (2) beds of clast-supported gravel alternate in vertical succession with beds of fine-grained sediment (sand, mud, and peat) in response to centennial-scale changes in snowmelt-driven peak discharges, and (3) alluvial strata provide information about Holocene climate history that complements the history provided by cirque moraines, periglacial deposits, and paleontological data. Most alluvial strata are of late Holocene age and record, among other things, that: (1) the largest peak flows since the end of the Pleistocene occurred during the late Holocene; (2) the occurrence of a mid- to late Holocene interval (~2450–1630(?) cal yr BP) of warmer climate, which is not clearly identified in palynological records; and (3) the Little Ice Age climate seems to have had little impact on stream channels, except perhaps for minor (~1 m) incision. Published

Holocene alluvial stratigraphy and response to climate change in the Roaring River valley, Front Range, Colorado, USA

NASA Astrophysics Data System (ADS)

Madole, Richard F.

2012-09-01

Stratigraphic analyses and radiocarbon geochronology of alluvial deposits exposed along the Roaring River, Colorado, lead to three principal conclusions: (1) the opinion that stream channels in the higher parts of the Front Range are relics of the Pleistocene and nonalluvial under the present climate, as argued in a water-rights trial USA v. Colorado, is untenable, (2) beds of clast-supported gravel alternate in vertical succession with beds of fine-grained sediment (sand, mud, and peat) in response to centennial-scale changes in snowmelt-driven peak discharges, and (3) alluvial strata provide information about Holocene climate history that complements the history provided by cirque moraines, periglacial deposits, and paleontological data. Most alluvial strata are of late Holocene age and record, among other things, that: (1) the largest peak flows since the end of the Pleistocene occurred during the late Holocene; (2) the occurrence of a mid- to late Holocene interval (~ 2450-1630(?) cal yr BP) of warmer climate, which is not clearly identified in palynological records; and (3) the Little Ice Age climate seems to have had little impact on stream channels, except perhaps for minor (~ 1 m) incision.

Hydrologic Setting and Conceptual Hydrologic Model of the Walker River Basin, West-Central Nevada

USGS Publications Warehouse

Lopes, Thomas J.; Allander, Kip K.

2009-01-01

The Walker River is the main source of inflow to Walker Lake, a closed-basin lake in west-central Nevada. Between 1882 and 2008, agricultural diversions resulted in a lake-level decline of more than 150 feet and storage loss of 7,400,000 acre-ft. Evaporative concentration increased dissolved solids from 2,500 to 17,000 milligrams per liter. The increase in salinity threatens the survival of the Lahontan cutthroat trout, a native species listed as threatened under the Endangered Species Act. This report describes the hydrologic setting of the Walker River basin and a conceptual hydrologic model of the relations among streams, groundwater, and Walker Lake with emphasis on the lower Walker River basin from Wabuska to Hawthorne, Nevada. The Walker River basin is about 3,950 square miles and straddles the California-Nevada border. Most streamflow originates as snowmelt in the Sierra Nevada. Spring runoff from the Sierra Nevada typically reaches its peak during late May to early June with as much as 2,800 cubic feet per second in the Walker River near Wabuska. Typically, 3 to 4 consecutive years of below average streamflow are followed by 1 or 2 years of average or above average streamflow. Mountain ranges are comprised of consolidated rocks with low hydraulic conductivities, but consolidated rocks transmit water where fractured. Unconsolidated sediments include fluvial deposits along the active channel of the Walker River, valley floors, alluvial slopes, and a playa. Sand and gravel deposited by the Walker River likely are discontinuous strata throughout the valley floor. Thick clay strata likely were deposited in Pleistocene Lake Lahontan and are horizontally continuous, except where strata have been eroded by the Walker River. At Walker Lake, sediments mostly are clay interbedded with alluvial slope, fluvial, and deltaic deposits along the lake margins. Coarse sediments form a multilayered, confined-aquifer system that could extend several miles from the shoreline. Depth to bedrock in the lower Walker River basin ranges from about 900 to 2,000 feet. The average hydraulic conductivity of the alluvial aquifer in the lower Walker River basin is 10-30 feet per day, except where comprised of fluvial sediments. Fluvial sediments along the Walker River have an average hydraulic conductivity of 70 feet per day. Subsurface flow was estimated to be 2,700 acre-feet per year through Double Spring. Subsurface discharge to Walker Lake was estimated to be 4,400 acre-feet per year from the south and 10,400 acre-feet per year from the north. Groundwater levels and groundwater storage have declined steadily in most of Smith and Mason Valleys since 1960. Groundwater levels around Schurz, Nevada, have changed little during the past 50 years. In the Whisky Flat area south of Hawthorne, Nevada, agricultural and municipal pumpage has lowered groundwater levels since 1956. The water-level decline in Walker Lake since 1882 has caused the surrounding alluvial aquifer to drain and groundwater levels to decline. The Wabuska streamflow-gaging station in northern Mason Valley demarcates the upper and lower Walker River basin. The hydrology of the lower Walker River basin is considerably different than the upper basin. The upper basin consists of valleys separated by consolidated-rock mountains. The alluvial aquifer in each valley thins or pinches out at the downstream end, forcing most groundwater to discharge along the river near where the river is gaged. The lower Walker River basin is one surface-water/groundwater system of losing and gaining reaches from Wabuska to Walker Lake, which makes determining stream losses and the direction and amount of subsurface flow difficult. Isotopic data indicate surface water and groundwater in the lower Walker River basin are from two sources of precipitation that have evaporated. The Walker River, groundwater along the Wassuk Range, and Walker Lake plot along one evaporation line. Groundwater along th

Holocene alluvium around Lefkosia (Nicosia), Cyprus: An archive of land-use, tectonic processes, and climate change

USGS Publications Warehouse

Newell, Wayne L.; Stone, B.; Harrison, R.; ,

2004-01-01

Holocene alluvium of the Pedhicos River around Lefkosia (Nicosia), Cyprus, was studied. Alluvial stratigraphy was found to present serial flood deposits underlying river terraces and an extensive alluvial fan. It was found that the stratigraphy and geomorphology of the alluvium can be interpreted to distinguish not only the effects of climate change, but also land-use change, and the impact of particular engineering works. It was suggested that details of the physical properties of the flood deposit sequences and paleosols can contribute to modeling various geophysical and engineering properties and in predicting response to vertical acceleration during earthquakes.

Summary of U.S. Geological Survey studies conducted in cooperation with the Citizen Potawatomi Nation, central Oklahoma, 2011–14

USGS Publications Warehouse

Andrews, William J.; Becker, Carol J.; Ryter, Derek W.; Smith, S. Jerrod

2016-01-19

Numerical groundwater-flow models were created to characterize flow systems in aquifers underlying this study area and areas of particular interest within the study area. Those models were used to estimate sustainable groundwater yields from parts of the North Canadian River alluvial aquifer, characterize groundwater/surface-water interactions, and estimate the effects of a 10-year simulated drought on streamflows and water levels in alluvial and bedrock aquifers. Pumping of wells at the Iron Horse Industrial Park was estimated to cause negligible infiltration of water from the adjoining North Canadian River. A 10-year simulated drought of 50 percent of normal recharge was tested for the period 1990–2000. For this period, the total amount of groundwater in storage was estimated to decrease by 8.6 percent in the North Canadian River alluvial aquifer and approximately 0.2 percent in the Central Oklahoma aquifer, and groundwater flow to streams was estimated to decrease by 28–37 percent. This volume of groundwater loss showed that the Central Oklahoma aquifer is a bedrock aquifer that has relatively low rates of recharge from the land surface. The simulated drought decreased simulated streamflow, composed of base flow, in the North Canadian River at Shawnee, Okla., which did not recover to predrought conditions until the relatively wet year of 2007 after the simulated drought period.

Decoding sediment transport dynamics on alluvial fans from spatial changes in grain size, Death Valley, California

NASA Astrophysics Data System (ADS)

Brooke, Sam; Whittaker, Alexander; Watkins, Stephen; Armitage, John

2017-04-01

How fluvial sediment transport processes are transmitted to the sedimentary record remains a complex problem for the interpretation of fluvial stratigraphy. Alluvial fans represent the condensed sedimentary archive of upstream fluvial processes, controlled by the interplay between tectonics and climate over time, infused with the complex signal of internal autogenic processes. With high sedimentation rates and near complete preservation, alluvial fans present a unique opportunity to tackle the problem of landscape sensitivity to external boundary conditions such as climate. For three coupled catchments-fan systems in the tectonically well-constrained northern Death Valley, we measure grain size trends across well-preserved Holocene and Late-Pleistocene deposits, which we have mapped in detail. Our results show that fan surfaces from the Late-Pleistocene are, on average, 50% coarser than counterpart active or Holocene fan surfaces, with clear variations in input grain sizes observed between surfaces of differing age. Furthermore, the change in ratio between mean grain size and standard deviation is stable downstream for all surfaces, satisfying the statistical definition of self-similarity. Applying a self-similarity model of selective deposition, we derive a relative mobility function directly from our grain size distributions, and we evaluate for each fan surface the grain size for which the ratio of the probability of transport to deposition is 1. We show that the "equally mobile" grain size lies in the range of 20 to 35 mm, varies over time, and is clearly lower in the Holocene than in the Pleistocene. Our results indicate that coarser grain sizes on alluvial fans are much less mobile than in river systems where such an analysis has been previously applied. These results support recent findings that alluvial fan sediment characteristics can be used as an archive of past environmental change and that landscapes are sensitive to environmental change over a glacial-interglacial cycle. Significantly, the self-similarity methodology offers a means to constrain relative mobility of grain sizes from field measurements where hydrological information is lost or irretrievable.

Conjunctive-use optimization model of the Mississippi River Valley alluvial aquifer of northeastern Arkansas

USGS Publications Warehouse

Czarnecki, John B.; Clark, Brian R.; Reed, Thomas B.

2003-01-01

The Mississippi River Valley alluvial aquifer is a water-bearing assemblage of gravels and sands that underlies about 32,000 square miles of Missouri, Kentucky, Tennessee, Mississippi, Louisiana, and Arkansas. Because of the heavy demands placed on the aquifer, several large cones of depression over 100 feet deep have formed in the potentiometric surface, resulting in lower well yields and degraded water quality in some areas. A ground-water flow model of the alluvial aquifer was previously developed for an area covering 14,104 square miles, extending northeast from the Arkansas River into the northeast corner of Arkansas and parts of southeastern Missouri. The flow model showed that continued ground-water withdrawals at rates commensurate with those of 1997 could not be sustained indefinitely without causing water levels to decline below half the original saturated thickness of the aquifer. To develop estimates of withdrawal rates that could be sustained in compliance with the constraints of critical ground-water area designation, conjunctive-use optimization modeling was applied to the flow model of the alluvial aquifer in northeastern Arkansas. Ground-water withdrawal rates form the basis for estimates of sustainable yield from the alluvial aquifer and from rivers specified within the alluvial aquifer model. A management problem was formulated as one of maximizing the sustainable yield from all ground-water and surface-water withdrawal cells within limits imposed by plausible withdrawal rates, and within specified constraints involving hydraulic head and streamflow. Steady-state flow conditions were selected because the maximized withdrawals are intended to represent sustainable yield of the system (a rate that can be maintained indefinitely). Within the optimization model, 11 rivers are specified. Surface-water diversion rates that occurred in 2000 were subtracted from specified overland flow at the appropriate river cells. Included in these diversions were the planned diversions of 63,339,248 ft3/d for the Bayou Meto project area and 55,078,367 ft3/d for the Grand Prairie project area, which factor in an additional 30 and 40 percent transmission loss, respectively. Streamflow constraints were specified at all 1,165 river cells based on average 7-day minimum flows for 10 years. Sustainable yield for all rivers ranged from 0 (Current, Little Red, and Bayou Meto Rivers) to almost 5 billion cubic feet per day for the Arkansas River. Total sustainable yield from all rivers combined was 12.8 billion cubic feet per day, which represents a substantial source for supplementing ground water to meet the total water demand. Sustainable-yield estimates are affected by the allowable upper limit on withdrawals from wells specified in the optimization model. Ground-water withdrawal rates were allowed to vary as much as 200 percent of the withdrawal rate in 1997. As the overall upper limit on withdrawals is increased, the sustainable yield generally increases. Tests with the optimization model show that without limits on pumping, wells adjacent to sources of water would have optimized withdrawal rates that were orders of magnitude larger than rates corresponding to those of 1997. The sustainable yield from ground water for the entire study area while setting the maximum upper limit as the amount withdrawn in 1997 is 360 million cubic feet per day, which is only about 57 percent of the amount withdrawn in 1997 (635.6 million cubic feet per day). Optimal sustainable yields from within the Bayou Meto irrigation project area and within the Grand Prairie irrigation project area are 18.1 and 9.1 million cubic feet per day, respectively, assuming a maximum allowable withdrawal rate equal to 1997 rates. These values of sustainable yield represent 35 and 30 percent respectively of the amount pumped from these project areas in 1997. Unmet demand (defined as the difference between the optimized withdrawal rate or sustainable yield, a

Bed load transport in gravel-bed rivers

Treesearch

Jeffrey J. Barry

2007-01-01

Bed load transport is a fundamental physical process in alluvial rivers, building and maintaining a channel geometry that reflects both the quantity and timing of water and the volume and caliber of sediment delivered from the watershed. A variety of formulae have been developed to predict bed load transport in gravel-bed rivers, but testing of the equations in natural...

User's manual for BRI-STARS (BRIdge Stream Tube model for Alluvial River Simulation)

DOT National Transportation Integrated Search

1998-07-01

There is a need for a generalized water and sediment-routing computer model for solving complicated river engineering problems with limited data and resources. This program should have the following capabilities: to compute hydraulic parameters for o...

Pliocene and Quaternary Deposits in the Northern Part of the San Juan Basin in Southwestern Colorado and Northwestern New Mexico

USGS Publications Warehouse

Scott, Glenn R.; Moore, David W.

2007-01-01

Unconsolidated late Cenozoic deposits in the northern part of the San Juan Basin range in age from late Pliocene to Holocene. Most of the deposits are alluvial gravel composed of resistant quartzite, sandstone, and igneous, metamorphic, and volcanic rocks derived from the uplifted central core of the San Juan Mountains 20-50 miles (32-80 kilometers) north of the basin. Alluvial deposits are most voluminous in the Animas Valley, but deposits of gravel of the same general age are present in the La Plata, Florida, Los Pinos, and Piedra River valleys as well. Alluvial gravel forms tabular deposits, generally about 20 feet (6 meters) thick, that are exposed beneath a sequence of terraces at many levels above the rivers. Gravel layers 360 feet (110 meters) or less above the Animas River are glacial outwash. The gravel layers begin at the south toes of end moraines and extend discontinuously downvalley at least 10-20 miles (16-32 kilometers). Farther south, distinction between outwash and nonglacial alluvium is problematical. Alluvial gravel beneath higher terraces does not grade to end moraines. Glacial till forms a series of end moraines at the north edge of the town of Durango. The oldest moraines are farthest downvalley, are higher above the river, and have more mature surficial soils than do moraines farther north. The two youngest moraines, the Animas City moraines, are interpreted to be Pinedale in age. They have narrow, ridgelike crests and form nearly unbroken arcs across the valley floor. Small segments of still more weathered moraines, the Spring Creek moraines, are 170-230 feet (52-70 meters) above the river and are 660-990 feet (200-300 meters) farther downvalley. The oldest moraines, the Durango moraines, are on the north end of the unnamed mesa on which Fort Lewis College is located. The base is about 180 feet (55 meters) above the river. These oldest moraines may be of Bull Lake age. Alluvial fans, pediment gravel, and landslides are scattered at several levels in various valleys within the northern San Juan Basin. Except where the Lava Creek B volcanic ash (0.639 mega-annum) is interbedded in them, these crudely bedded accumulations of sandy or clayey material washed from side drainages and added little to our reconnaissance stratigraphic study. Scattered landslide deposits consist of unsorted, mixed soil and fragments of rock. Loess and local silty and clayey sheetwash alluvium 6-12 feet (2-4 meters) thick form a veneer on low terraces. On higher terraces, such as Red Mesa east of the La Plata River and Florida Mesa east of the Animas River, loess and sheetwash alluvium generally are about 20 feet (6 meters) thick but can be as thick as 40-50 feet (12-15 meters) in places on Florida Mesa. When using the Lava Creek B volcanic ash as a time datum, apparently the timing of late Cenozoic continental deposition in the region was broadly similar to that in the Denver Basin-Front Range region and some other glaciated mountain ranges in the Rocky Mountains. A more accurate dating of Quaternary alluviation must await a thorough dating of the deposits. Thick, extensive outwash gravel indicates enhanced deposition during glacial epochs.

Hydrogeology and water quality in the Snake River alluvial aquifer at Jackson Hole Airport, Jackson, Wyoming, September 2008-June 2009

USGS Publications Warehouse

Wright, Peter R.

2010-01-01

The hydrogeology and water quality of the Snake River alluvial aquifer, at the Jackson Hole Airport in northwest Wyoming, was studied by the U.S. Geological Survey in cooperation with the Jackson Hole Airport Board and the Teton Conservation District during September 2008-June 2009. Hydrogeologic conditions were characterized using data collected from 14 Jackson Hole Airport wells. Groundwater levels are summarized in this report and the direction of groundwater flow, hydraulic gradients, and estimated groundwater velocity rates in the Snake River alluvial aquifer underlying the study area are presented. Analytical results of chemical, dissolved gas, and stable isotopes are presented and summarized. Seasonally, the water table at Jackson Hole Airport was lowest in early spring and reached its peak in July, with an increase of 12 to 14 feet between April and July 2009. Groundwater flow was predominantly horizontal but had the hydraulic potential for downward flow. The direction of groundwater flow was from the northeast to the west-southwest. Horizontal groundwater velocities within the Snake River alluvial aquifer at the airport were estimated to be about 26 to 66 feet per day. This indicates that the traveltime from the farthest upgradient well to the farthest downgradient well was approximately 53 to 138 days. This estimate only describes the movement of groundwater because some solutes may move at a rate much slower than groundwater flow through the aquifer. The quality of the water in the alluvial aquifer generally was considered good. The alluvial aquifer was a fresh, hard to very hard, calcium carbonate type water. No constituents were detected at concentrations exceeding U.S. Environmental Protection Agency Maximum Contaminant Levels, and no anthropogenic compounds were detected at concentrations greater than laboratory reporting levels. The quality of groundwater in the alluvial aquifer generally was suitable for domestic and other uses; however, dissolved iron and manganese were detected at concentrations exceeding the U.S. Environmental Protection Agency Secondary Maximum Contaminant Levels for drinking water in two monitoring wells. These secondary standards are esthetic guidelines only and are nonenforceable. Iron and manganese are likely both natural components of the geologic materials in the area and may have become mobilized in the aquifer due to reduction/oxidation (redox) processes. Additionally, measurements of dissolved-oxygen concentrations and analyses of major ions and nutrients indicate reducing conditions exist at two of the seven wells sampled. Reducing conditions in an otherwise oxic aquifer system are indicative of an upgradient or in-situ source of organic carbon. The nature of the source of organic carbon at the airport could not be determined. View report for unabridged abstract.

Analysis of equivalent widths of alluvial channels and application for instream habitat in the Rio Grande

Treesearch

Claudia A. Leon

2003-01-01

Rivers are natural systems that adjust to variable water and sediment discharges. Channels with spatial variability in width that are managed to maintain constant widths over a period of time are able to transport the same water and sediment discharges by adjusting the bed slope. Methods developed to de ne equilibrium hydraulic geometry characteristics of alluvial...

Groundwater quality in the Northern Coast Ranges Basins, California

USGS Publications Warehouse

Mathany, Timothy M.; Belitz, Kenneth

2015-01-01

Recharge to the groundwater system is primarily from mixture of ambient sources, including direct percolation of precipitation and irrigation waters, infiltration of runoff from surrounding hills/areas, seepage from rivers and creeks, and subsurface inflow (from non-alluvial geologic units that bound the alluvial basins). The primary sources of discharge are evaporation, discharge to streams, and water pumped for municipal supply and irrigation.

Landscape disequilibrium on 1000-10,000 year scales Marsyandi River, Nepal, central Himalaya

NASA Astrophysics Data System (ADS)

Pratt-Sitaula, Beth; Burbank, Douglas W.; Heimsath, Arjun; Ojha, Tank

2004-03-01

In an actively deforming orogen, maintenance of a topographic steady state requires that hillslope erosion, river incision, and rock uplift rates are balanced over timescales of 10 5-10 7 years. Over shorter times, <10 5 years, hillslope erosion and bedrock river incision rates fluctuate with changes in climate. On 10 4-year timescales, the Marsyandi River in the central Nepal Himalaya has oscillated between bedrock incision and valley alluviation in response to changes in monsoon intensity and sediment flux. Stratigraphy and 14C ages of fill terrace deposits reveal a major alluviation, coincident with a monsoonal maximum, ca. 50-35 ky BP. Cosmogenic 10Be and 26Al exposure ages define an alluviation and reincision event ca. 9-6 ky BP, also at a time of strong South Asian monsoons. The terrace deposits that line the Lesser Himalayan channel are largely composed of debris flows which originate in the Greater Himalayan rocks up to 40 km away. The terrace sequences contain many cubic kilometers of sediment, but probably represent only 2-8% of the sediments which flushed through the Marsyandi during the accumulation period. At ˜10 4-year timescales, maximum bedrock incision rates are ˜7 mm/year in the Greater Himalaya and ˜1.5 mm/year in the Lesser Himalayan Mahabarat Range. We propose a model in which river channel erosion is temporally out-of-phase with hillslope erosion. Increased monsoonal precipitation causes an increase in hillslope-derived sediment that overwhelms the transport capacity of the river. The resulting aggradation protects the bedrock channel from erosion, allowing the river gradient to steepen as rock uplift continues. When the alluvium is later removed and the bedrock channel re-exposed, bedrock incision rates probably accelerate beyond the long-term mean as the river gradient adjusts downward toward a more "equilibrium" profile. Efforts to document dynamic equilibrium in active orogens require quantification of rates over time intervals significantly exceeding the scale of these millennial fluctuations in rate.

Vertical distribution of 137Cs in alluvial soils of the Lokna River floodplain (Tula oblast) long after the Chernobyl accident and its simulation

NASA Astrophysics Data System (ADS)

Mamikhin, S. V.; Golosov, V. N.; Paramonova, T. A.; Shamshurina, E. N.; Ivanov, M. M.

2016-12-01

Profiles of vertical 137Cs distribution in alluvial meadow soils on the low and medium levels of the Lokna River floodplain (central part of the Plavsk radioactive spot in Tula oblast) 28 years after the Chernobyl fallout have been studied. A significant increase in the 137Cs pool is revealed on the low floodplain areas compared to the soils of interfluves due to the accumulation of alluvium, which hampers the reduction of the total radionuclide pool in alluvial soils because of radioactive decay. The rate of alluvium accumulation in the soil on the medium floodplain level is lower by three times on average. An imitation prognostic model has been developed, which considers the flooding and climatic conditions in the region under study. Numerical experiments have quantitatively confirmed the deciding role of low-mobile forms in the migration of maximum 137Cs content along the soil profile in the absence of manifested erosion-accumulation processes.

Controls on alluvial fans morphology

NASA Astrophysics Data System (ADS)

Delorme, P.; Devauchelle, O.; Lajeunesse, E.; Barrier, L.; Métivier, F.

2017-12-01

Using laboratory experiments, we investigate the influence of water and sediment discharges on the morphology of an alluvial fan. In our flume, a single-thread laminar river deposits corundum sand (0.4 mm) into a conical fan. We record the fan progradation with top-view images, and measure its shape using the deformation of a Moiré pattern. The fan remains virtually self-affine as it grows, with a nearly constant slope. We find that, when the sediment discharge is small, the longitudinal slope of the fan remains close to that of a river at the threshold for sediment transport. A higher sediment discharge causes the fan's slope to depart from the threshold value. Due to the downstream decrease of the sediment load, this slope gets shallower towards the fan's toe. This mechanism generates a slightly concave fan profile. This suggests that the proximal slope of an alluvial fan could be a proxy for the sediment flux that feeds the fan.Finally, we discuss the applicability of these results to natural systems.

Impacts of reforestation upon sediment load and water outflow in the Lower Yazoo River Watershed, Mississippi

Treesearch

Ying Ouyang; Theodor D. Leininger; Matt Moran

2013-01-01

Among the world’s largest coastal and river basins, the Lower Mississippi River Alluvial Valley (LMRAV)is one of the most disturbed by human activities. This study ascertained the impacts of reforestation on water outflow attenuation (i.e., water flow out of the watershed outlet) and sediment load reduction in the Lower Yazoo River Watershed (LYRW) within the LMRAV...

Ground-Water Geology and Hydrology of the Kern River Alluvial-Fan Area, California

USGS Publications Warehouse

Dale, R.H.; French, James J.; Gordon, G.V.

1966-01-01

The Kern River alluvial fan is the southernmost major alluvial fan built by the streams which drain the west side of the Sierra Nevada. The climate is semiarid with rainfall near 5 inches per year. Agricultural development within the area uses over half the 700,000 acre-feet per year flow of the Kern River, plus a considerable amount drawn from the ground-water reservoir particularly during periods of low flow. The area overlies a deep structural trough between crystalline rocks of the Sierra Nevada and the marine rocks of Tertiary age of the Coast Ranges. The top horizon of the marine rocks that lap on the Sierra Nevada block underlies the report area at an average depth of 2,000 feet. The overlying continental deposits that form the groundwater reservoir consist of alluvial-fan and lacustrine deposits. The continental deposits are subdivided into three lithologic units on the basis of grain size and sorting. The gravel and clay unit consists of older alluvial-fan material, of both Sierra Nevada and Coast Range provenance, that shows extremely poor sorting with some diagenetic decomposition through chemical weathering. The fine sand to clay unit consists principally of fine sand, silt, and clay deposited in a lacustrine environment, although some of the unit is of alluvial-fan origin derived from poorly consolidated marine shale of the Coast Ranges. Within the fine sand to clay unit three distinct clays, which affect ground-water conditions, can be recognized. The gravel to medium sand unit consists of unweathered alluvial-fan material that shows much better sorting than the gravel and clay unit. In the eastern part of the area the basal part of this unit is a gravel lentil that can be traced in the subsurface more than 250 square miles. The overlying deposits consist principally of medium sand. In the western part of the area the unit is a heterogeneous gravel and sand unit. Permeability in Meinzer units of the gravel and clay unit ranges between 10 and 100 with specific yield about 5 percent. For the fine sand to clay unit the permeability ranges between 0.0001 and 100 with about 10 percent specific yield. The gravel to medium sand unit has permeabilities between 100 and 10,000, and specific yield is about 15 percent. For the period 1955-59 the annual gross surface-water supply was estimated at 421,000 acre-feet and pumpage was 664,000 acre-feet, giving a rounded total supply of 1,100,000 acre-feet. Annual consumptive use was estimated at 750,000 acre-feet and annual infiltration at 350,000 acre-feet. The approximate 300,000 acre-feet difference between 664,000 acre-feet pumped and 350,000 acre-feet infiltrated has caused an annual decline in water levels of up to 7 feet. Ground water occurs under both unconfined and confined conditions within the report area. In general, the gravel to medium sand unit contains unconfined water, and the other two units contain confined water. Pumping is less intense in the Kern River fan area than in the adjoining areas to the north or south. This fact, plus infiltration from the Kern River, results in ground-water movement being principally out of the area. There is a ground-water divide that approximately underlies the Kern River. South of the river the flow spreads out semicircularly from the river, and north of the river the flow is linear to the northwest. Based on chemical quality the ground water has been divided areally into (1) east side, (2) west side, and (3) axial water. With the exception of two areas of comparable size northwest of Bakersfield and a much smaller area southeast of that city where ground water is somewhat saline, east-side ground water is generally of the calcium bicarbonate and calcium sodium bicarbonate type of low to medium salinity. The chemical character of east-side ground water is necessarily related to that of Kern River water, the principal source of recharge, and water of intermittent streams which drain the dissected upland

Groundwater-Surface Water Interactions and Downstream Transport of Water, Heat, and Solutes in a Hydropeaked River

NASA Astrophysics Data System (ADS)

Ferencz, S. B.; Cardenas, M. B.; Neilson, B. T.; Watson, J.

2017-12-01

A majority of the world's largest river systems are regulated by dams. In addition to being used for water resources management and flood prevention, many large dams are also used for hydroelectric power generation. In the United States, dams account for 7% of domestic electricity, and hydropower accounts for 16% of worldwide electricity production. To help meet electricity demand during peak usage times, hydropower utilities often increase their releases of water during high demand periods. This practice, termed hydropeaking, can cause large transient flow regimes downstream of hydroelectric dams. These transient flow increases can result in order of magnitude daily fluctuations in discharge, and the released water can have different thermal and chemical properties than ambient river water. As hydropeaking releases travel downstream, the temporary rise in stage and increase in discharge can enhance surface water-groundwater (SW-GW) exchange between the river and its alluvial aquifer. This dam-induced SW-GW exchange, combined with hydrodynamic attenuation and heat exchange processes, result in complex responses downstream. The dam-regulated Lower Colorado River downstream of Austin, TX was used as a natural laboratory to observe SW-GW interactions and downstream transport of water, heat, and solutes under hydropeaking conditions. To characterize SW-GW interactions, well transects were installed in the banks of the river to observe exchanges between the river and alluvial aquifer. The well transects were installed at three different distances from the dam (15km, 35km, and 80km). At each well transect conductivity, temperature, and pressure sensors were deployed in the monitoring wells and in the channel. Additional conductivity and temperature sensors were deployed along the study reach to provide a more detailed record of heat and solute transport during hydropeaking releases. The field data spans over two months of daily dam releases that were punctuated by two large natural storm events. To our knowledge, this study is the first to use multiple downstream field sites to characterize how dam-induced SW-GW interactions and in-stream temperature and solute transport behave under hydropeaking conditions.

A Froude-scaled model of a bedrock-alluvial channel reach: 1. Hydraulics

NASA Astrophysics Data System (ADS)

Hodge, Rebecca A.; Hoey, Trevor B.

2016-09-01

The controls on hydraulics in bedrock-alluvial rivers are relatively poorly understood, despite the importance of the flow in determining rates and patterns of sediment transport and consequent erosion. To measure hydraulics within a bedrock-alluvial channel, we developed a 1:10 Froude-scaled laboratory model of an 18 × 9 m bedrock-alluvial river reach using terrestrial laser scanning and 3-D printing. In the reported experiments, water depth and velocity were recorded at 18 locations within the channel at each of five different discharges. Additional data from runs with sediment cover in the flume were used to evaluate the hydraulic impact of sediment cover; the deposition and erosion of sediment patches in these runs are analyzed in the companion paper. In our data (1) spatial variation in both flow velocity and Froude number increases with discharge; (2) bulk flow resistance and Froude number become independent of discharge at higher discharges; (3) local flow velocity and Reynolds stress are correlated to the range of local bed topography at some, but not most, discharges; (4) at lower discharges, local topography induces vertical flow structures and slower velocities, but these effects decrease at higher discharges; and (5) there is a relationship between the linear combination of bed and sediment roughness and local flow velocity. These results demonstrate the control that bedrock topography exerts over both local and reach-scale flow conditions, but spatially distributed hydraulic data from bedrock-alluvial channels with different topographies are needed to generalize these findings.

Variations in fluvial deposition on an alluvial plain: an example from the Tongue River Member of the Fort Union Formation (Paleocene), southeastern Powder River Basin, Wyoming, U.S.A.

USGS Publications Warehouse

Johnson, E.A.; Pierce, F.W.

1990-01-01

The Tongue River Member of the Paleocene Fort Union Formation is an important coal-bearing sedimentary unit in the Powder River Basin of Wyoming and Montana. We studied the depositional environments of a portion of this member at three sites 20 km apart in the southeastern part of the basin. Six lithofacies are recognized that we assign to five depositional facies categorized as either channel or interchannel-wetlands environments. (1) Type A sandstone is cross stratified and occurs as lenticular bodies with concave-upward basal surfaces; these bodies are assigned to the channel facies interpreted to be the product of low-sinuosity streams. (2) Type B sandstone occurs in parallel-bedded units containing mudrock partings and fossil plant debris; these units constitute the levee facies. (3) Type C sandstone typically lacks internal structure and occurs as tabular bodies separating finer grained deposits; these bodies represent the crevasse-splay facies. (4) Gray mudrock is generally nonlaminated and contains ironstone concretions; these deposits constitute the floodplain facies. (5) Carbonaceous shale and coal are assigned to the swamp facies. We recognize two styles of stream deposition in our study area. Laterally continuous complexes of single and multistoried channel bodies occur at our middle study site and we interpret these to be the deposits of sandy braided stream systems. In the two adjacent study sites, single and multistoried channel bodies are isolated in a matrix of finer-grained interchannel sediment suggesting deposition by anastomosed streams. A depositional model for our study area contains northwest-trending braided stream systems. Avulsions of these systems created anastomosed streams that flowed into adjacent interchannel areas. We propose that during late Paleocene a broad alluvial plain existed on the southeastern flank of the Powder River Basin. The braided streams that crossed this surface were tributaries to a northward-flowing, basin-axis trunk stream that existed to the west. ?? 1990.

Resolving tectonic, climatic, and geomorphologic signatures in the Eocene Green River Formation, Western U.S

NASA Astrophysics Data System (ADS)

Smith, M. E.; Carroll, A. R.

2011-12-01

Tectonic lake basins are windows into the co-evolution of terrestrial climate and topography, but the stratigraphic responses to these drivers are complex and incompletely understood. Coring Quaternary lake basins has provided excellent temporal resolution, but is limited to one-dimensional archives of relatively short duration. Conversely, outcrop-based studies of older deposits can elucidate complex lateral facies relationships and longer time periods, but temporal resolution is often poor due to the lack of marine fossils. However, recent advances in radioisotopic dating have produced highly-resolved records of older lacustrine strata, provided volcanic ash beds are present. The Eocene Green River Formation in Wyoming, Colorado, and Utah is such a record, containing numerous 40Ar/39Ar-dated ash horizons with c.a. ±200 ky 2σ uncertainties. At the scale of individual Members of the Green River Formation (100-400 m), lithofacies and faunas differentiate five distinct lake-type intervals: Luman-Scheggs (fluviolacustrine), Rife (saline), Wilkins Peak (hypersaline-alluvial), Lower LaClede (saline), and Upper LaClede (fluviolacustrine). Although published explanations implicate tectonic and/or climatic control of these changes, both lack significant correlation to bulk lithofacies. While stratal geometries imply that the Uinta Mountains were the principle Eocene driver of flexural subsidence for the Greater Green River Basin (GGRB), conglomerate compositions reveal progressive Paleocene through Eocene unroofing rather than a discreet Early Eocene pulse of Laramide tectonism. Similarly, paleofloral evidence for climatic changes is equivocal. Instead, regional provenance and paleoflow patterns suggest that lake-type changes resulted from progressive hydrologic isolation of the GGRB from orogenic highlands to the west, hydrologic closure, then subsequent integration. From ~53 to ~51.5 Ma, Lake Gosiute expanded from a restricted freshwater to expansive saline lake. Abrupt diversion of a stream originating from the Cordilleran divide at ~51.5 Ma led to alternating deposition of the evaporative Wilkins Peak Member. Another Cordilleran stream carrying debris from the Challis Volcanic Field was subsequently redirected into the GGRB between 49.5 and 49 Ma, allowing the lake to reach its most expansive state, overflow, then progressively infill with volcaniclastic alluvium (Bridger and Washakie Formations) from 49 to 48 Ma. The most convincing example in the Green River Formation of the influence of climate-driven changes occurs at the "bed" scale. Cyclic repetitions of facies, long interpreted to reflect the influence of orbital periodicities, are most pronounced in the evaporative Wilkins Peak Member, where the most prominent periodicity is 10-20 meter scale alternations between lacustrine and alluvial strata. Lacustine intervals contain organic-rich micritic carbonates and bedded evaporates, and alluvial intervals are comprised of fine-grained siliciclastic alluvium with vertebrate traces, incipient pedogenesis, and no evaporite minerals. Interpolation between seven 40Ar/39Ar-dated ash beds indicates that these alternations have a well defined ~100 ky periodicity, a good fit for short eccentricity.

Numerical model of the lowermost Mississippi River as an alluvial-bedrock reach: preliminary results

NASA Astrophysics Data System (ADS)

Viparelli, E.; Nittrouer, J. A.; Mohrig, D. C.; Parker, G.

2012-12-01

Recent field studies reveal that the river bed of the Lower Mississippi River is characterized by a transition from alluvium (upstream) to bedrock (downstream). In particular, in the downstream 250 km of the river, fields of actively migrating bedforms alternate with deep zones where a consolidated substratum is exposed. Here we present a first version of a one-dimensional numerical model able to capture the alluvial-bedrock transition in the lowermost Mississippi River, defined herein as the 500-km reach between the Old River Control Structure and the Gulf of Mexico. The flow is assumed to be steady, and the cross-section is divided in two regions, the river channel and the floodplain. The streamwise variation of channel and floodplain geometry is described with synthetic relations derived from field observations. Flow resistance in the river channel is computed with the formulation for low-slope, large sand bed rivers due to Wright and Parker, while a Chezy-type formulation is implemented on the floodplain. Sediment is modeled in terms of bed material and wash load. Suspended load is computed with the Wright-Parker formulation. This treatment allows either uniform sediment or a mixture of different grain sizes, and accounts for stratification effects. Bedload transport rates are estimated with the relation for sediment mixtures of Ashida and Michiue. Previous work documents reasonable agreement between these load relations and field measurements. Washload is routed through the system solving the equation of mass conservation of sediment in suspension in the water column. The gradual transition from the alluvial reach to the bedrock reach is modeled in terms of a "mushy" layer of specified thickness overlying the non-erodible substrate. In the case of a fully alluvial reach, the channel bed elevation is above this mushy layer, while in the case of partial alluvial cover of the substratum, the channel bed elevation is within the mushy layer. Variations in base level are accounted for in terms of a specified rate of sea level rise. In addition, the model allows a subsidence rate that varies in space and time. The time rate of change of channel bed elevation is computed solving the equation of mass conservation of the bed material. Validation of the model against field data is currently in progress in a relatively simplified setting, in which the bed material is characterized in terms of a single grain size. In addition, due to the lack of information on the geometry and the grain size characteristics of the floodplain, the modeling effort is restricted to the channel bed, and the procedure to route the washload through the system is not implemented. Having clearly in mind that the present Lowermost Mississippi River is not in equilibrium, validation runs are performed in two steps. The model is first run under pre-1930 conditions, under the assumption that the natural Mississippi River was not too far from long-term steady-state. The model is then run from the 1930s to the 2010s with the prevailing inputs of water and sediment and the model results are compared against field data. In the near future we plan to test the model with non-uniform bed material, and extend it to include inundation of the floodplain, and deposition of washload on it.

Surficial geology and stratigraphy of Pleistocene Lake Manix, San Bernardino County, California

USGS Publications Warehouse

Reheis, Marith C.; Redwine, Joanna R.; Wan, Elmira; McGeehin, John P.; VanSistine, D. Paco

2014-01-01

Pluvial Lake Manix and its surrounding drainage basin, in the central Mojave Desert of California, has been a focus of paleoclimate, surficial processes, and neotectonic studies by the U.S. Geological Survey (USGS) since about 2004. The USGS initiated studies of Lake Manix deposits to improve understanding of the paleoclimatic record and the shifts in atmospheric circulation that controlled precipitation in the Mojave Desert. Until approximately 25,000 years ago, Lake Manix was the terminus of the Mojave River, which drains northeasterly from the San Bernardino Mountains; the river currently terminates in the Soda Lake and Silver Lake playas. Pleistocene Lake Manix occupied several subbasins at its maximum extent. This map focuses on the extensive exposures created by incision of the Mojave River and its tributaries into the interbedded lacustrine and alluvial deposits within the central (Cady) and northeastern (Afton) subbasins of Lake Manix, and extends from the head of Afton Canyon to Manix Wash. The map illuminates the geomorphic development and depositional history of the lake and alluvial fans within the active tectonic setting of the eastern California shear zone, especially interactions with the left-lateral Manix fault. Lake Manix left an extraordinarily detailed but complex record of numerous transgressive-regressive sequences separated by desiccation and deposition of fan, eolian, and fluvial deposits, and punctuated by tectonic movements and a catastrophic flood that reconfigured the lake basin. Through careful observation of the intercalated lacustrine and fan sequences and by determining the precise elevations of unit contacts, this record was decoded to understand the response of the lake and river system to the interplay of climatic, geomorphic, and tectonic forces. These deposits are exposed in steep badland topography. Mapping was carried out mostly at scales of 1:12,000, although the map is presented at 1:24,000 scale, and employs custom unit nomenclature, with multiple subdivided lacustrine and alluvial fan units. In addition, many important units are very thin and cannot be mapped separately, or are covered by thin eolian sand, so these are commonly portrayed as stacks of units or combined units. These details are more accurately portrayed in the measured sections that accompany the map. Altitudes of many contacts were obtained using differentially corrected Global Positioning System (GPS) or, in some cases, lidar (light detection and ranging) data.

High-resolution fluvial records of Holocene environmental changes in the Sahel: the Yamé River at Ounjougou (Mali, West Africa)

NASA Astrophysics Data System (ADS)

Lespez, L.; Le Drezen, Y.; Garnier, A.; Rasse, M.; Eichhorn, B.; Ozainne, S.; Ballouche, A.; Neumann, K.; Huysecom, E.

2011-03-01

The Yamé river, in the Bandiagara Plateau, Dogon Country, Mali, is characterised by extensive alluvial sedimentary records, particularly in the 1 km long Ounjougou reach where Holocene floodplain pockets are inset in the Pleistocene formations. These alluvial records have been investigated via geomorphologic fieldwork and sedimentologic and micromorphologic analyses and are supported by 79 radiocarbon dates. The alluvial deposits of the valley floor correspond to a vertical accretion of 3-10 m. The reconstruction of fluvial style changes provides evidence of four main aggradation periods. From 11,500 to 8760 cal. BP, the alluvial architecture and grain-size parameters indicate a wandering river. This period included phases of pulsed high-energy floods and avulsion related to a northward shift of the summer monsoon to around 14°N after 11,500 cal. BP. From 7800 to 5300 cal. BP, a swampy floodplain environment with standing water pools within a Sudanian savanna/woodland mosaic corresponds to the culmination of the Holocene humid period. From 3800 cal. BP onwards, rhythmic sedimentation attests to an increase in the duration and/or intensity of the dry season, giving a precise date for the local termination of the Holocene Optimum period. During the last two millennia and for the first time during the Holocene, the alluvial formations are progressively restricted whereas the colluvial deposits increase, indicating strong soil erosion and redeposition within the watershed related to an increase in human impact. Four major periods are characterised by incision (I1: ante 11,500, I2: 8760-7800; I3: 6790-6500 cal. BP; I4; 2400-1700 cal. BP) pointing to dramatic changes in fluvial style. They result from high-energy flood flows during dry spells and confirm the capacity of the floodplain pocket in the upstream reach of the Sahelian belt to record rapid Holocene climatic change.

Freshwater mussel assemblage structure in a regulated river in the Lower Mississippi river Alluvial Basin, USA

Treesearch

Wendell R. Haag; Melvin L. Warren

2007-01-01

1. This paper documents a diverse, reproducing freshwater mussel community (20 species) in Lower Lake } an impounded, regulated portion of the Little Tallahatchie River below Sardis Dam in Panola Co., Mississippi, USA. 2. Despite being regulated and impounded, the lake has a heterogeneous array of habitats that differ markedly in mussel community attributes...

Nucleation of Waterfalls at Fault Scarps Temporarily Shielded By Alluvial Fan Aggradation.

NASA Astrophysics Data System (ADS)

Malatesta, L. C.; Lamb, M. P.

2014-12-01

Waterfalls are important components of mountain river systems and they can serve as an agent to transfer tectonic, climatic, or authigenic signals upstream through a catchment. Retreating waterfalls lower the local base level of the adjacent hillslopes, and temporarily increase sediment delivery to the fluvial system. Their creation is often attributed to seismic ruptures, lithological boundaries, or the coalescence of multiple smaller steps. We explore here a mechanism for the nucleation of waterfalls that does not rely on sudden seismic slip but on the build-up of accumulated slip during periods of fault burial by fluvial aggradation. Alluvial fans are common features at the front of mountain ranges bound by normal or thrust faults. Climate change or internal forcing in the mountain catchment modifies the equilibrium slope of alluvial fans. When alluvial fans aggrade, they shield the active fault scarp from fluvial erosion allowing the scarp to grow undisturbed. The scarp may then be exposed when the channel incises into the fan exposing a new bedrock waterfall. We explore this mechanism analytically and using a numerical model for bedrock river incision and sediment deposition. We find that the creation of waterfalls by scarp burial is limited by three distinct timescales: 1) the critical timescale for the scarp to grow to the burial height, 2) the timescale of alluvial re-grading of the fan, and 3) the timescale of the external or internal forcing, such as climate change. The height of the waterfall is controlled by i) the difference in equilibrium alluvial-fan slopes, ii) the ratio of the respective fan and catchment sizes, iii) the catchment wide denudation rate, and iv) the fault slip rate. We test whether an individual waterfall could be produced by alluvial shielding of a scarp, and identify the tectonic, climatic, or authigenic nature of waterfalls using example field sites in the southwest United States.

EXPLOITATION OF FLOODPLAIN RESOURCES BY ADULT LARGESCALE SUCKER OF THE WILLAMETTE RIVER, OREGON

EPA Science Inventory

We tested two predictions of the flood-pulse concept on a large, temperate alluvial river that historically flooded an extensive fringing floodplain. We predicted adult largescale sucker, Catostomus macrocheilus, would: (1) migrate onto the floodplain during high water; and (2) e...

Changes of chromium concentration in alluvial sediments of the Obra river valley

NASA Astrophysics Data System (ADS)

Młynarczyk, Z.; Sobczyński, T.; Słowik, M.

2006-06-01

In this research work, changes in concentration of the chosen chemical element in alluvial sediments have been used to estimate the relative age of floodplain deposits. The research concerning changes of chromium concentration in alluvial deposits was done in the Obra river valley near Międzyrzecz (Western Poland). Chromium was chosen because of its low ability to migrate in groundwater environment. Moreover, this chemical element was used in the process of dyeing textures in Międzyrzecz between the sixteenth and the nineteenth century. Confrontation of changes in chromium concentration and age of alluvial sediments (age estimated in years BP using radiocarbon method) have shown that the sediments with higher chromium contents are much older than the period of development of the weaving industry in Międzyrzecz. Therefore, it is not possible to use changes in chromium concentration to estimate relative age of floodplain sediments. Despite information in the literature about low migration ability of this chemical component (Macioszczyk and Dobrzyński in Hydrogeochemia: strefy aktywnej wymiany wód podziemnych. PWN, Warszawa, 2002; Ball and Izbicki in Appl Geochem 19:1123 1135, 2004) migration of chromium is so intensive that distinct changes in its concentration are observed even before the period of increased human activity.

Geohydrology and water quality of the North Platte River alluvial aquifer, Garden County, Western Nebraska

USGS Publications Warehouse

Steele, Gregory V.; Cannia, James C.

1995-01-01

In 1993, a 3-year study was begun to describe the geohydrology and water quality of the North Platte River alluvial aquifer near Oshkosh, Garden County, Nebraska. The study's objectives are to evaluate the geohydrologic characteristics of the alluvial aquifer and to establish a network of observation wells for long-term monitoring of temporal variations and spatial distributions of nitrate and major-ion concentrations. Monitor wells were installed at 11 sites near Oshkosh. The geohydrology of the aquifer was characterized based on water-level measurements and two short-term aquifer tests. Bimonthly water samples were collected and analyzed for pH, specific conductivity, water temperature, dissolved oxygen, and nutrients that included dissolved nitrate. Concentrations of major ions were defined from analyses of semiannual water samples. Analyses of the geohydrologic and water-quality data indicate that the aquifer is vulnerable to nitrate contamination. These data also show that nitrate concentrations in ground water flowing into and out of the study area are less than the U.S. Environmental Protection Agency's Maximum Concentration Level of 10 milligrams per liter for drinking water. Ground water from Lost Creek Valley may be mixing with ground water in the North Platte River Valley, somewhat moderating nitrate concentrations near Oshkosh.

Reconnaissance evaluation of contamination in the alluvial aquifer in the East Poplar oil field, Roosevelt County, Montana

USGS Publications Warehouse

Levings, G.W.

1984-01-01

Water moving from north to south in the alluvial aquifer of the Poplar River valley becomes contaminated with sodium chloride in the area underlain by the East Poplar oil fields. Four types of ground water were identified in the study area. Type 1 is sodium bicarbonate water. Type 2 is sodium chloride water with varying quantities of calcium and magnesium. Type 3 water contains sodium and chloride in significantly larger concentrations than Type 2. Type 4 water is the brine being injected into brine-disposal wells. Contamination of the alluvial aquifer is indicated by a brine-freshwater interface in the alluvium, by downstream increase in chloride concentration of the Poplar River, and by downstream change in water type of the Poplar River. Contamination also may be indicated by the distribution of iron and manganese concentrations in water from wells near a brine-disposal well. Possible sources of sodium chloride contamination in the alluvium are brine-disposal wells, pipelines, and storage or evaporation pits. The contamination can occur from leaks in the casing of disposal wells or in pipelines caused by the corrosive nature of the brine or from storage or evaporation pits that have been improperly sealed or have sustained tears in the sealing material. (USGS)

Taphonomy and paleoecology of nonmarine mollusca: indicators of alluvial plain lacustrine sedimentation, upper part of the Tongue River Member, Fort Union Formation ( Paleocene), Northern Powder River Basin, Wyoming and Montana ( USA).

USGS Publications Warehouse

Hanley, J.H.; Flores, R.M.

1987-01-01

The composition, species abundances, and spatial and temporal distributions of mollusc assemblages were controlled by the environments in which they lived and the depositional processes that affected the molluscs after death and before final burial. Post-mortem transport, reworking and concentration of shells, and mixing of faunal elements from discrete habitats produced a taphonomic 'overprint' on assemblage characteristics that directly reflects the processes of alluvial plain and floodbasin lacustrine sedimentation. The 'overprint' can be interpreted from outcrop analysis of molluscan biofabric, which consists of: 1) orientation, fragmentation, size-sorting, abrasion, density, and dispersion of shells, 2) the nature and extent of shell-infilling, and 3) ratio of articulated to disarticulated bivalves. Taphonomic characteristics were used with sedimentological properties to differentiate in-place, reworked, transported, and ecologically mixed mollusc assemblages. This study also defines the paleoecology of habitat preferences of mollusc species as a basis for recognition of the environments in which these assemblages were deposited: 1) large floodbasin lakes, 2) small floodbasin lakes, and 3) crevasse deltas and splays. Integration of sedimentology and paleoecology provides an interdisciplinary approach to the interpretation of alluvial environments through time in the Tongue River Member. -Authors

River-aquifer interactions and their relationship to stygofauna assemblages: a case study of the Gwydir River alluvial aquifer (New South Wales, Australia).

PubMed

Menció, A; Korbel, K L; Hose, G C

2014-05-01

In contrast to surface water ecosystems, groundwater ecosystems are usually considered to have relatively stable conditions and physically inert environments. However, many groundwater ecosystems undergo substantial changes through space and time, related to fluxes in groundwater flow, exchange and nutrient imports. In this study we used hydrochemical data to: 1) determine the different hydrogeological conditions in an alluvial system, the shallow Gwydir River alluvial aquifer (located in Northern New South Wales, Australia); and 2) analyze the relationship between hydrochemical conditions and the composition of stygofauna assemblages in the aquifer. Using hydrochemical modeling and multivariate analyses, four main hydrogeological situations were defined as occurring in the aquifer. Bores were classified as having either a high, low or no influence from or exchange with the river. The latter group was further subdivided into those of low and high salinity. Further analysis combining the biological and hydrochemical data identified two main groups of samples. The first group was composed mainly of samples related to the aquifer groundwater which had higher richness and abundance of fauna compared to samples in the second group which was comprised of samples affected by stream water leakage and samples related to the highest salinities. These results suggest that more stable conditions (mainly related to steadier groundwater head levels) and lower nitrate concentrations promoted a more diverse and abundant stygofauna community. Copyright © 2014 Elsevier B.V. All rights reserved.

Inventory and Comparison of Floodplain Embankment along Large Rivers

NASA Astrophysics Data System (ADS)

Hudson, Paul

2016-04-01

Flood control is a fundamental human response to flood risk, and floodplain embankment by dike (levee) construction is among the oldest forms of societal impacts to natural systems. Large lowland alluvial valleys are some of Earth's most distinctive environments and represent high levels of geodiversity and biodiversity. Embankment of large lowland alluvial river valleys alters fundamental processes related to floodplain hydrology, sedimentation, and ecology and eventually results in a transformation of the embanked floodplain environment. Since embankment, many large lowland floodplains have been heaviliy modified for floodplain agriculture and include high population densities, increasing flood risk. While there is much discussion about the pros and cons of dike construction and the impact to floodplain environments there is no systematic inventory which documents the magnitude and intensity of floodplain embankment to lowland rivers. In this study we characterize and inventory floodplain embankment along large lowland alluvial valleys. The review includes some of Earth's largest embanked fluvial systems, and primarilly focuses on northern hemisphere rivers in the United States, Europe and Asia. Data sources includes the U.S. National Levee Database, SRTM DEM, recently obtained high resolution satellite imagery, various national topographic map series, and hydrologic data from the published literature. These data are integrated into a GIS framework to facilitate the measurement and characterisation of floodplain embankment. Spatial indices of floodplain embankment are constructed, including the intensity of embankment and how it relates to the natural floodplain and constriction of flooding.

Establishment area and biogeomorphic feedback window of three pioneer riparian Salicaceae species within a dynamic riparian corridor (Allier River, France)

NASA Astrophysics Data System (ADS)

Hortobágyi, Borbála; Corenblit, Dov; Steiger, Johannes; Peiry, Jean-Luc

2017-04-01

Within riparian corridors, biotic-abiotic feedback mechanisms occur between woody vegetation which is highly influenced by hydrogeomorphic constraints (e.g. sediment transport and deposition, shear stress, hydrological variability), fluvial landforms and morphodynamics, which in turn are modulated by established vegetation. During field investigations in spring 2015 we analysed on 16 alluvial bars (e.g. point and lateral bars) within the dynamic riparian corridor of the Allier River, France, the aptitude of three pioneer riparian Salicaceae tree species (Populus nigra L., Salix purpurea L. and Salix alba L.) to establish and to act as ecosystem engineers by trapping sediment and constructing fluvial landforms. Our aim was to empirically identify the preferential establishment area (EA; i.e. the local areas where species establish) and the preferential biogeomorphic feedback window (BFW; i.e. where and to what extent the species affect geomorphology) of these three species on alluvial bars within a river reach of a length of 20 km. Our results show that the EA and BFW of all three species significantly varied along the longitudinal, i.e. upstream-downstream exposure on the alluvial bars, and the transverse gradient, i.e. main channel-floodplain gradient of hydrological connectivity. In the current context of the Allier River it appeared that P. nigra, which is the most abundant species, acts as the main engineer species affecting landform dynamics at the bar scale; S. purpurea establishes and acts as an ecosystem engineer in the locations on the alluvial bars which are the most exposed to hydrosedimentary flow dynamics, while S. alba establishes on the bar tail in the vicinity of secondary channels and affects geomorphology in mixed patches with P. nigra. Thus, our study underlines the role of functional trait diversity of riparian engineer species in controlling the extent of fluvial landform construction along geomorphic gradients within riparian corridors exposed to frequent hydrogeomorphic disturbances.

Selected hydrologic data from the Cedar Rapids area, Linn County, Iowa, April 1996 through March 1999

USGS Publications Warehouse

Boyd, R.A.; Kuzniar, R.L.; Schulmeyer, P.M.

1999-01-01

The City of Cedar Rapids, Iowa obtains its municipal water supply from four well fields along the Cedar River. The wells are completed at depths of about 60 to 80 feet in a shallow alluvial aquifer adjacent to the Cedar River. The City of Cedar Rapids and the U.S. Geological Survey have conducted a cooperative study of the groundwater flow system and water quality near the well fields since 1992. The purpose of this report is to document selected hydrologic data collected from April 1996 through March 1999. Data include the results of water-quality analyses, ground-waterlevels continuously measured with pressure transducers and data recorders, and physical properties continuously monitored using multiprobe instruments. Water-quality samples were collected from selected wells and the Cedar River to conduct periodic monitoring, to evaluate ground-water geochemistry, to assess the occurrence of pesticides and herbicide degradates in the alluvial aquifer, and to characterize water quality in shallow ground water near a wetland area in the Seminole Well Field. Types of water-quality analyses included common ions (calcium, chloride, iron, magnesium, manganese, potassium, silica, sodium, and sulfate), trace elements (boron, bromide, and fluoride), nutrients (ammonia as nitrogen, nitrite as nitrogen, nitrite plus nitrate as nitrogen, and orthophosphate as phosphorus), dissolved organic carbon, and selected pesticides and herbicide degradates. Ground-water levels in selected observation wells were continuously measured to assess temporal trends in groundwater levels in the alluvial aquifer and bedrock aquifer, to help calibrate a ground-water flow model being constructed to simulate local groundwater flow under transient conditions near the well fields, and to assess hydrologic conditions near a wetland area in the Seminole Well Field. Physical properties (specific conductance, pH, dissolved oxygen, and water temperature) were continuously monitored to assess temporal variation and to help evaluate the interaction between the Cedar River and ground water in the alluvial aquifer.

Using Remote Sensing and High-Resolution Digital Elevation Models to Identify Potential Erosional Hotspots Along River Channels During High Discharge Storm Events

NASA Astrophysics Data System (ADS)

Orland, E. D.; Amidon, W. H.

2017-12-01

As global warming intensifies, large precipitation events and associated floods are becoming increasingly common. Channel adjustments during floods can occur by both erosion and deposition of sediment, often damaging infrastructure in the process. There is thus a need for predictive models that can help managers identify river reaches that are most prone to adjustment during storms. Because rivers in post-glacial landscapes often flow over a mixture of bedrock and alluvial substrates, the identification of bedrock vs. alluvial channel reaches is an important first step in predicting vulnerability to channel adjustment during flood events, especially because bedrock channels are unlikely to adjust significantly, even during floods. This study develops a semi-automated approach to predicting channel substrate using a high-resolution LiDAR-derived digital elevation model (DEM). The study area is the Middlebury River in Middlebury, VT-a well-studied watershed with a wide variety of channel substrates, including reaches with documented channel adjustments during recent flooding events. Multiple metrics were considered for reference—such as channel width and drainage area—but the study utilized channel slope as a key parameter for identifying morphological variations within the Middlebury River. Using data extracted from the DEM, a power law was fit to selected slope and drainage area values for each branch in order to model idealized slope-drainage area relationships, which were then compared with measured slope-drainage area relationships. Differences in measured slope minus predicted slope (called delta-slope) are shown to help predict river channel substrate. Compared with field observations, higher delta-slope values correlate with more stable, boulder rich channels or bedrock gorges; conversely the lowest delta-slope values correlate with flat, sediment rich alluvial channels. The delta-slope metric thus serves as a reliable first-order predictor of channel substrate in the Middlebury River, which in turn can be used to help identify local reaches that are most vulnerable to channel adjustment during large flood events.

Ground-water flow patterns and water budget of a bottomland forested wetland, Black Swamp, eastern Arkansas

USGS Publications Warehouse

Gonthier, G.J.; Kleiss, B.A.

1996-01-01

The U.S. Geological Survey, working in cooperation with the U.S. Army Corps of Engineers, Waterways Experiment Station, collected surface-water and ground-water data from 119 wells and 13 staff gages from September 1989 to September 1992 to describe ground-water flow patterns and water budget in the Black Swamp, a bottomland forested wetland in eastern Arkansas. The study area was between two streamflow gaging stations located about 30.5 river miles apart on the Cache River. Ground-water flow was from northwest to southeast with some diversion toward the Cache River. Hydraulic connection between the surface water and the alluvial aquifer is indicated by nearly equal changes in surface-water and ground-water levels near the Cache River. Diurnal fluctuations of hydraulic head ranged from more than 0 to 0.38 feet and were caused by evapotranspiration. Changes in hydraulic head of the alluvial aquifer beneath the wetland lagged behind stage fluctuations and created the potential for changes in ground-water movement. Differences between surface-water levels in the wetland and stage of the Cache River created a frequently occurring local ground-water flow condition in which surface water in the wetland seeped into the upper part of the alluvial aquifer and then seeped into the Cache River. When the Cache River flooded the wetland, ground water consistently seeped to the surface during falling surface-water stage and surface water seeped into the ground during rising surface-water stage. Ground-water flow was a minor component of the water budget, accounting for less than 1 percent of both inflow and outflow. Surface-water drainage from the study area through diversion canals was not accounted for in the water budget and may be the reason for a surplus of water in the budget. Even though ground-water flow volume is small compared to other water budget components, ground-water seepage to the wetland surface may still be vital to some wetland functions.

Hyporheic exchange in mountain rivers I: Mechanics and environmental effects

Treesearch

Daniele Tonina; John M. Buffington

2009-01-01

Hyporheic exchange is the mixing of surface and shallow subsurface water through porous sediment surrounding a river and is driven by spatial and temporal variations in channel characteristics (streambed pressure, bed mobility, alluvial volume and hydraulic conductivity). The significance of hyporheic exchange in linking fluvial geomorphology, groundwater, and riverine...

Simulation of morphological changes due to dam removal

USDA-ARS?s Scientific Manuscript database

In this chapter, a brief review of numerical models and their applications for impact assessment of dam removal on sediment transport and morphological changes in alluvial rivers is given. As an example, a one-dimensional river flow and sediment transport model, CCHE1D, is applied to assess morpholo...

FULL-SCALE EVALUATION OF RIVERBANK FILTRATION AT THREE MIDWEST WATER TREATMENT PLANTS

EPA Science Inventory

Riverbank filtration (or induced infiltration) is a process in which river water passes through ground prior to its use as a drinking water supply. Alluvial aquifers that are hydraulically connected to rivers may provide an alternate source of water supply for water utilities. Ri...

Morphodynamics structures induced by variations of the channel width

NASA Astrophysics Data System (ADS)

Duro, Gonzalo; Crosato, Alessandra; Tassi, Pablo

2014-05-01

In alluvial channels, forcing effects, such as a longitudinally varying width, can induce the formation of steady bars (Olesen, 1984). The type of bars that form, such as alternate, central or multiple, will mainly depend on the local flow width-to-depth ratio and on upstream conditions (Struiksma et al., 1985). The effects on bar formation of varying the channel width received attention only recently and investigations, based on flume experiments and mathematical modelling, are mostly restricted to small longitudinal sinusoidal variations of the channel width (e.g. Repetto et al., 2002; Wu and Yeh, 2005, Zolezzi et al., 2012; Frascati and Lanzoni, 2013). In this work, we analyze the variations in equilibrium bed topography in a longitudinal width-varying channel with characteristic scales of the Waal River (The Netherlands) using two different 2D depth-averaged morphodynamic models, one based on the Delft3D code and one on Telemac-Mascaret system. In particular, we explore the effects of changing the wavelength of sinusoidal width variations in a straight channel, focusing on the effects of the spatial lag between bar formation and forcing that is observed in numerical models and laboratory experiments (e.g. Crosato et al, 2011). We extend the investigations to finite width variations in which longitudinal changes of the width-to-depth ratio are such that they may affect the type of bars that become unstable (alternate, central or multiple bars). Numerical results are qualitatively validated with field observations and the resulting morphodynamic pattern is compared with the physics-based predictor of river bar modes by Crosato and Mosselman (2009). The numerical models are finally used to analyse the experimental conditions of Wu and Yeh (2005). The study should be seen as merely exploratory. The aim is to investigate possible approaches for future research aiming at assessing the effects of artificial river widening and narrowing to control bar formation in alluvial rivers. References Crosato A. and Mosselman E., 2009. Simple physics-based predictor for the number of river bars and the transition between meandering and braiding. Water Resources Research, 45, W03424, doi: 10.1029/2008WR007242. Crosato A., Mosselman E., Desta F.B. and Uijttewaal W.S.J., 2011. Experimental and numerical evidence for intrinsic nonmigrating bars in alluvial channels. Water Resources Research, AGU, 47(3), W03511, doi 10.1029/2010WR009714. Frascati A. and Lanzoni S., 2013. A mathematical model for meandering rivers with varying width. J. Geophys. Res.Earth Surf., 118, doi:10.1002/jgrf.20084. Olesen K.W., 1984. Alternate bars in and meandering of alluvial rivers. In: River Meandering, Proc. of the Conf. Rivers '83, 24-26 Oct. 1983, New Orleans, Louisiana, U.S.A., ed. Elliott C.M., pp. 873-884, ASCE, New York. ISBN 0-87262-393-9. Repetto R., Tubino, M. and Paola C., 2002. Planimetric instability of channels with variable width. J. Fluid Mech., 457, 79-109. Struiksma N., Olesen K.W., Flokstra C. and De Vriend H.J., 1985. Bed deformation in curved alluvial channels. J. Hydraul. Res., 23(1), 57- 79. Wu F.-C. and Yeh T.-H., 2005. Forced bars induced by variations of channel width: Implications for incipient bifurcation. J. Geophys. Res., 110, F02009, doi:10.1029/2004JF000160. Zolezzi, G., R. Luchi, and M. Tubino (2012), Modeling morphodynamic processes in meandering rivers with spatial width variations, Rev. Geophys., 50, RG4005, doi:10.1029/2012RG000392.

A Real Options Method for Estimating the Adoption Potential of Forestry and Agroforestry Systems on Private Lands in the Lower Mississippi Alluvial Valley, USA

Treesearch

Gregory E. Frey; D. Evan Mercer; Frederick W. Cubbage; Robert C. Abt

2010-01-01

The Lower Mississippi River Alluvial Valley (LMAV), once was the largest forested bottom-land area in the continental United States, but has undergone widespread loss of forest through conversion to farmland. Restoration of forest functions and values has been a key conservation goal in the LMAV since the 1970s. This study utilizes a partial differential real options...

Occurrence and behavior of selected pharmaceuticals during riverbank filtration in The Republic of Serbia.

PubMed

Kovačević, Srđan; Radišić, Marina; Laušević, Mila; Dimkić, Milan

2017-01-01

The objectives of the research are to determine the occurrence of pharmaceuticals in surface water and groundwater in the Republic of Serbia and to identify significant effects of river-water purification through riverbank filtration, concerning oxic conditions and hydrogeological conditions of alluvial aquifers in Serbia. Between 2009 and 2015, a total of 19 studied pharmaceuticals and metabolites were analyzed in 184 samples, 10 were detected in surface water, and 8 in groundwater. Carbamazepine and metamizole metabolites N-acetyl-4-amino-antipyrine (4-AAA) and N-formyl-4-amino-antipyrine (4-FAA) have the highest frequency of occurrence in surface water (57.3-68.8 %) and in groundwater (19.5-43.9 %), respectively. Highest detected concentrations were for 4-AAA (520 ng/L) and 4-FAA (248 ng/L) in surface water as well as in groundwater (4-AAA 128 ng/L and 4-FAA 150 ng/L). Results showed that riverbank filtration sites with different hydrogeological and oxic conditions could significantly remove investigated pharmaceuticals. Percentage of removal during riverbank filtration was determined for carbamazepine (65.4 %), trimethoprim (100 %), 4-AAA (91.2 %), and 4-FAA (70 %) for all investigated locations. Based on the available data for three specific locations (Danube River alluvion, Sava River alluvion, and Velika Morava River alluvion), results showed that besides oxic conditions, residence time of groundwater in alluvial aquifer and ratio of infiltrated water from river to the well play very important role in the quality of groundwater. These results are extremely important for better understanding of self-purification potential of alluvial aquifers and protection from potential impacts of anthropogenic pollution to the groundwater sources in the Republic of Serbia.

Sinuous Ridge on the Orson Welles Bajada

NASA Image and Video Library

2015-04-22

Alluvial fans are piles of debris dumped by rivers when they emerge from the mountains and enter a mostly dry valley as seen by NASA Mars Reconnaissance Orbiter. A bajada (such as this example named after the famous American filmmaker) consists of a series of coalescing alluvial fans along a mountain front. On the surface of this bajada, one can see many sinuous ridges. These ridges mark the path that streams of water took as they flowed into this crater. The sinuosity of the ridges tells us something about the speed of the water flow. Fast moving flows tend to be straighter than slow-moving. Observations like this help us build a picture of how rivers behaved on ancient Mars. http://photojournal.jpl.nasa.gov/catalog/PIA19366

Lake Murray, Fly and Strickland River Basins, Papua, New Guinea

NASA Image and Video Library

1991-12-01

Lake Murray, a manmade reservoir, lies between the Fly and Strickland River Basins, Papua, New Guinea (7.0S, 141.5E). The region, photographed in sunglint, shows the water level in the reservoir and the full extent of the drainage basins of both river systems as the rivers meander through wide alluvial floodplains. Some forest clearing can be seen in places throughout the region, but most of the area remains in closed canopy forest.

The combined use of dynamic factor analysis and wavelet analysis to evaluate latent factors controlling complex groundwater level fluctuations in a riverside alluvial aquifer

NASA Astrophysics Data System (ADS)

Oh, Yun-Yeong; Yun, Seong-Taek; Yu, Soonyoung; Hamm, Se-Yeong

2017-12-01

To identify and quantitatively evaluate complex latent factors controlling groundwater level (GWL) fluctuations in a riverside alluvial aquifer influenced by barrage construction, we developed the combined use of dynamic factor analysis (DFA) and wavelet analysis (WA). Time series data of GWL, river water level and precipitation were collected for 3 years (July 2012 to June 2015) from an alluvial aquifer underneath an agricultural area of the Nakdong river basin, South Korea. Based on the wavelet coefficients of the final approximation, the GWL data was clustered into three groups (WCG1 to WCG3). Two dynamic factors (DFs) were then extracted using DFA for each group; thus, six major factors were extracted. Next, the time-frequency variability of the extracted DFs was examined using multiresolution cross-correlation analysis (MRCCA) with the following steps: 1) major driving forces and their scales in GWL fluctuations were identified by comparing maximum correlation coefficients (rmax) between DFs and the GWL time series and 2) the results were supplemented using the wavelet transformed coherence (WTC) analysis between DFs and the hydrological time series. Finally, relative contributions of six major DFs to the GWL fluctuations could be quantitatively assessed by calculating the effective dynamic efficiency (Def). The characteristics and relevant process of the identified six DFs are: 1) WCG1DF4,1 as an indicative of seasonal agricultural pumping (scales = 64-128 days; rmax = 0.68-0.89; Def ≤ 23.1%); 2) WCG1DF4,4 representing the cycle of regional groundwater recharge (scales = 64-128 days; rmax = 0.98-1.00; Def ≤ 11.1%); 3) WCG2DF4,1 indicating the complex interaction between the episodes of precipitation and direct runoff (scales = 2-8 days; rmax = 0.82-0.91; Def ≤ 35.3%) and seasonal GW-RW interaction (scales = 64-128 days; rmax = 0.76-0.91; Def ≤ 14.2%); 4) WCG2DF4,4 reflecting the complex effects of seasonal pervasive pumping and the local recharge cycle (scales = 64-128 days; rmax = 0.86-0.94; Def ≤ 16.4%); 5) WCG3DF4,2 as the result of temporal pumping (scales = 2-8 days; rmax = 0.98-0.99; Def ≤ 7.7%); and 6) WCG3DF4,4 indicating the local recharge cycle (scales = 64-128 days; rmax = 0.76-0.91; Def ≤ 34.2 %). This study shows that major driving forces controlling GWL time series data in a complex hydrological setting can be identified and quantitatively evaluated by the combined use of DFA and WA and applying MRCCA and WTC.

Influence of alluvial cover and lithology on the adjustment characteristics of semi-alluvial bedrock channels

NASA Astrophysics Data System (ADS)

Ferguson, Sean P.; Rennie, Colin D.

2017-05-01

A growing body of research has focused on evaluating the adjustment characteristics of semi-alluvial channels containing proximate bedrock, mixed, and alluvial sections. Active orogens have been the focus of most empirical field-based studies with comparatively less focus on semi-alluvial bedrock channels located in other regions. In this study, we present an inventory of channel geometry data collected from semi-alluvial bedrock channels in Ontario and Québec, Canada, which are not subject to tectonic uplift. Data were sourced from a variety of physiographic settings, permitting evaluation of the influence of alluvial cover, lithology, and gradient on cross-sectional channel form. Our results show no substantial difference in channel width or scaling behaviour amongst bedrock, mixed, and alluvial channels included in our study, except for sedimentary bedrock channels virtually bare of alluvial cover that represent a uniquely wide, distinct subgroup. Channel gradient does not appear to exhibit any observable control on channel width amongst our study rivers, suggesting that sedimentary bedrock channels form a distinct subgroup because of lithology. Comparatively, the widths of our bedrock channels formed in igneous/metamorphic bedrock are comparable to the widths of mixed channels and alluvial channels for a given discharge and drainage area. Our findings also suggest that cross-sectional adjustment of sedimentary bedrock channels is achieved through lateral erosion of the channel banks and downward erosion of the channel bed, whereas cross-sectional adjustment of igneous/metamorphic bedrock is primarily achieved through downward erosion of the bed with limited lateral erosion of the banks.

Rapid post-seismic landslide evacuation boosted by dynamic river width

NASA Astrophysics Data System (ADS)

Croissant, Thomas; Lague, Dimitri; Steer, Philippe; Davy, Philippe

2017-09-01

Mass wasting caused by large-magnitude earthquakes chokes mountain rivers with several cubic kilometres of sediment. The timescale and mechanisms by which rivers evacuate small to gigantic landslide deposits are poorly known, but are critical for predicting post-seismic geomorphic hazards, interpreting the signature of earthquakes in sedimentary archives and deciphering the coupling between erosion and tectonics. Here, we use a new 2D hydro-sedimentary evolution model to demonstrate that river self-organization into a narrower alluvial channel overlying the bedrock valley dramatically increases sediment transport capacity and reduces export time of gigantic landslides by orders of magnitude compared with existing theory. Predicted export times obey a universal non-linear relationship of landslide volume and pre-landslide valley transport capacity. Upscaling these results to realistic populations of landslides shows that removing half of the total coarse sediment volume introduced by large earthquakes in the fluvial network would typically take 5 to 25 years in various tectonically active mountain belts, with little impact of earthquake magnitude and climate. Dynamic alluvial channel narrowing is therefore a key, previously unrecognized mechanism by which mountain rivers rapidly digest extreme events and maintain their capacity to incise uplifted rocks.

Groundwater hydrology and estimation of horizontal groundwater flux from the Rio Grande at selected locations in Albuquerque, New Mexico, 2009–10

USGS Publications Warehouse

Rankin, Dale R.; Oelsner, Gretchen P.; McCoy, Kurt J.; Goeff J.M. Moret,; Jeffery A. Worthington,; Kimberly M. Bandy-Baldwin,

2016-03-17

The Albuquerque area of New Mexico has two principal sources of water: (1) groundwater from the Santa Fe Group aquifer system, and (2) surface water from the Rio Grande. From 1960 to 2002, pumping from the Santa Fe Group aquifer system caused groundwater levels to decline more than 120 feet while water-level declines along the Rio Grande in Albuquerque were generally less than 40 feet. These differences in water-level declines in the Albuquerque area have resulted in a great deal of interest in quantifying the river-aquifer interaction associated with the Rio Grande.In 2003, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, acting as fiscal agent for the Middle Rio Grande Endangered Species Collaborative Program, and the U.S. Army Corps of Engineers, began a study to characterize the hydrogeology of the Rio Grande inner valley alluvial aquifer in the Albuquerque area of New Mexico. The study provides hydrologic data in order to enhance the understanding of rates of water leakage from the Rio Grande to the alluvial aquifer, groundwater flow through the aquifer, and discharge of water from the aquifer to riverside drains. The study area extends about 20 miles along the Rio Grande in the Albuquerque area. Piezometers and surface-water gages were installed in paired transects at eight locations. Nested piezometers, completed at various depths in the alluvial aquifer, and surface-water gages, installed in the Rio Grande and riverside drains, were instrumented with pressure transducers. Water-level and water-temperature data were collected from 2009 to 2010.Water levels from the piezometers indicated that groundwater movement was usually away from the river towards the riverside drains. Annual mean horizontal groundwater gradients in the inner valley alluvial aquifer ranged from 0.0024 (I-25 East) to 0.0144 (Pajarito East). The median hydraulic conductivity values of the inner valley alluvial aquifer, determined from slug tests, ranged from 30 feet per day (ft/d) (Montaño) to 120 ft/d (Central) for paired transects, with a median hydraulic conductivity for all transects of 50 ft/d. Daily mean groundwater fluxes from the river through the inner valley alluvial aquifer computed using Darcy’s Law and the slug test results ranged from about 0.01 ft/d (Montaño West) to between 1.0 and 2.0 ft/d (Central East). Median annual groundwater fluxes from the river through the inner valley alluvial aquifer determined using the Suzuki-Stallman method was greatest at Alameda East (0.50 ft/d) and lowest at Alameda West (0.25 ft/d). The results from both methods agreed reasonably well.Seepage investigations conducted by measuring discharge in the east and west riverside drains provided information for computing changes in flow within the drains and for evaluating results from Darcy’s Law and Suzuki-Stallman method flux calculations. Discharge measured in the east riverside drain between the Barelas Bridge and the I-25 bridge indicated that the flow in the east riverside drain increased by an average of 56.5 cubic feet per day per linear foot (ft3/d/ft) of drain. Discharge measured in the west riverside drain between the Central bridge and the I-25 bridge indicated that flow increased between west drain miles 0 and 4, an average of 53.8 ft3/d/ft of drain, and that flow increased between west drain miles 7 and 10, an average of 44.9 ft3/d/ft of drain. In comparison to the seepage measurement results, the groundwater fluxes from the river through the inner valley alluvial aquifer calculated from Darcy’s Law (qslug) and by the Suzuki-Stallman method (qheat) would account for 20–36 percent or 53–95 percent, respectively, of the total flow in the east riverside drain and 22–31 percent or 19–26 percent, respectively, of the total flow in the west drain. These results indicate that the drains likely also receive water from outside the inner valley.The spatial variability of horizontal hydraulic gradients and groundwater fluxes can be primarily attributed to variability in the distances between the river and riverside drains throughout the study area and geologic heterogeneities in the alluvial aquifer. Temporal variability in the water levels, which control the horizontal hydraulic gradients and fluxes between the Rio Grande and the riverside drains, can be primarily attributed to seasonal fluctuations in river stage and irrigation practices.

Evaluation of Selected Model Constraints and Variables on Simulated Sustainable Yield from the Mississippi River Valley Alluvial Aquifer System in Arkansas

USGS Publications Warehouse

Czarnecki, John B.

2008-01-01

An existing conjunctive use optimization model of the Mississippi River Valley alluvial aquifer was used to evaluate the effect of selected constraints and model variables on ground-water sustainable yield. Modifications to the optimization model were made to evaluate the effects of varying (1) the upper limit of ground-water withdrawal rates, (2) the streamflow constraint associated with the White River, and (3) the specified stage of the White River. Upper limits of ground-water withdrawal rates were reduced to 75, 50, and 25 percent of the 1997 ground-water withdrawal rates. As the upper limit is reduced, the spatial distribution of sustainable pumping increases, although the total sustainable pumping from the entire model area decreases. In addition, the number of binding constraint points decreases. In a separate analysis, the streamflow constraint associated with the White River was optimized, resulting in an estimate of the maximum sustainable streamflow at DeValls Bluff, Arkansas, the site of potential surface-water withdrawals from the White River for the Grand Prairie Area Demonstration Project. The maximum sustainable streamflow, however, is less than the amount of streamflow allocated in the spring during the paddlefish spawning period. Finally, decreasing the specified stage of the White River was done to evaluate a hypothetical river stage that might result if the White River were to breach the Melinda Head Cut Structure, one of several manmade diversions that prevents the White River from permanently joining the Arkansas River. A reduction in the stage of the White River causes reductions in the sustainable yield of ground water.

Vegetation, Soil, and Flooding Relationships in a Blackwater Floodplain Forest

Treesearch

Sammy L. King; David Gartner; Mark H. Eisenbies

2003-01-01

Hydroperiod is considered the primary determinant of plant species distribution in temperate floodplain forests, but most studies have focused on alluvial (sediment-laden) river systems. Few studies have evaluated plant community relationships in blackwater river systems of the South Atlantic Coastal Plain of North America. In this study. we characterized the soils....

Bottomland oak afforestation in the lower Mississippi

Treesearch

Emile S. Gardiner; Brian Roy Lockhard

2007-01-01

The 11 million hectare Lower Mississippi Alluvial Valley (LMAV), which is the geologic floodplain of the lower Mississippi River, is a prominent physiographic region in the southern United States. Seven states (Arkansas, Louisiana, Missis- 1 sippi, Missouri, Kentucky, Illinois, and Tennessee) border the lower stretch of the II River, and have a portion of their land...

Early findings from artificial recharge efforts of the Mississippi River Valley Alluvial Aquifer

USDA-ARS?s Scientific Manuscript database

The long-term success and sustainability of agriculture in the Lower Mississippi River Basin will depend largely on water resources. Aquifer decline in the region has been documented since the 1980s and continues today. Artificial recharge is one possible tool that could help alleviate this declin...

On-farm irrigation reservoirs in two Arkansas critical groundwater regions: A comparative inventory

USDA-ARS?s Scientific Manuscript database

Arkansas, which ranks third in the nation in terms of irrigated cropland, relies heavily on the Mississippi River Valley alluvial aquifer for irrigation. Two critical groundwater areas have been identified, with one along the Cache River in northeast Arkansas and the other in the Grand Prairie in ce...

Temporal-spatial variation and source apportionment of soil heavy metals in the representative river-alluviation depositional system.

PubMed

Wang, Cheng; Yang, Zhongfang; Zhong, Cong; Ji, Junfeng

2016-09-01

The contributions of major driving forces on temporal changes of heavy metals in the soil in a representative river-alluviation area at the lower of Yangtze River were successfully quantified by combining geostatistics analysis with the modified principal component scores & multiple linear regressions approach (PCS-MLR). The results showed that the temporal (2003-2014) changes of Cu, Zn, Ni and Cr presented a similar spatial distribution pattern, whereas the Cd and Hg showed the distinctive patterns. The temporal changes of soil Cu, Zn, Ni and Cr may be predominated by the emission of the shipbuilding industry, whereas the significant changes of Cd and Hg were possibly predominated by the geochemical and geographical processes, such as the erosion of the Yangtze River water and leaching because of soil acidification. The emission of metal-bearing shipbuilding industry contributed an estimated 74%-83% of the changes in concentrations of Cu, Zn, Ni and Cr, whereas the geochemical and geographical processes may contribute 58% of change of Cd in the soil and 59% of decrease of Hg. Copyright © 2016 Elsevier Ltd. All rights reserved.

Large wood dynamics and biophysical consequences for riparian forests: A comparison of an unconfined alluvial river in a temperate rainforest and a bedrock confined river in a semi-arid South African savanna.

NASA Astrophysics Data System (ADS)

Latterell, J. J.; Pettit, N. E.; Naiman, R. J.

2005-05-01

Large wood shapes the geomorphology and ecology of rivers. We determined the origin, distribution, and fate of large wood in two rivers from contrasting environments. The Queets is an unstable temperate, rainforest river running from the Olympic Mountains (USA) through a glacial valley with colossal trees. In most years, the channel erodes a variety of forested landforms which forms jams that sculpt habitats. Many are displaced in a few years. Remaining jams initiate landform development and forest renewal. Thus, wood is stockpiled in the floodplain where it may become buried. Channel movements recapture most logs within 50 years. In contrast, the Sabie is a perennial river running through a confined bedrock channel in a fire-prone semi-arid South African savanna. Riparian trees are relatively small and many sink in water. A recent flood (February 2000) devastated the riparian forest, introducing wood to the channel. Jams formed on toppled trees, transported logs, and bedrock outcrops. Many trees survived and resprouted. Jams facilitated the establishment of woody plant seedlings and the intrusion of fire into riparian areas. Sunken wood formed unique depositional features. The Queets and Sabie rivers are strikingly different systems. However, large wood appears to promote the renewal and development of complex riparian forests in both rivers.

Revegetation of Riparian Trees and Shrubs on Alluvial Soils Along the Upper Sacramento River, 1987-1988

Treesearch

Steven P. Chainey; F. Jordan Lang; Skip Mills

1989-01-01

Two sites on the Sacramento River near Red Bluff and Colusa, California were planted with seven native tree species plus valley elderberry (a shrub) in an effort to mitigate for the loss of woody riparian vegetation from bank protection construction projects in the area. The stateowned environmental easements on terraces on the river side of the levees had been planted...

Geologic map of the Masters 7.5' quadrangle, Weld and Morgan Counties, Colorado

USGS Publications Warehouse

Berry, Margaret E.; Slate, Janet L.; Paces, James B.; Hanson, Paul R.; Brandt, Theodore R.

2015-09-28

The Masters 7.5' quadrangle is located along the South Platte River corridor on the semiarid plains of eastern Colorado and contains surficial deposits that record alluvial, eolian, and hillslope processes that have operated in concert with environmental changes from Pleistocene to present time. The South Platte River, originating high in the Colorado Front Range, has played a major role in shaping the surficial geology of the quadrangle, which is situated downstream of where the last of the major headwater tributaries (St. Vrain, Big Thompson, and Cache la Poudre) join the river. Recurrent glaciation (and deglaciation) of basin headwaters affected river discharge and sediment supply far downstream, influencing deposition of alluvium and terrace formation in the Masters quadrangle. Kiowa and Bijou Creeks, unglaciated tributaries originating in the Colorado Piedmont east of the Front Range and joining the South Platte River just downstream of the Masters quadrangle, also have played a major role by periodically delivering large volumes of sediment to the river during flood events, which may have temporarily dammed the river. Eolian sand deposits of the Greeley (north of river) and Fort Morgan (south of river) dune fields cover much of the quadrangle and record past episodes of sand mobilization during times of prolonged drought. With the onset of irrigation and damming during historical times, the South Platte River has changed from a broad, shallow sandy braided river with highly seasonal discharge to a much narrower, deeper river with braided-meandering transition morphology and more uniform discharge. Along the reach of river in the Masters quadrangle, the river has incised into Upper Cretaceous Pierre Shale, which, although buried by alluvial deposits here, is locally exposed downstream along the South Platte River bluff near the Bijou Creek confluence, in some of the larger draws, and along Wildcat Creek.

Hydraulic and field water-chemistry characteristics of piedmont alluvial deposits in the Middle Tyger River near Lyman, Spartanburg County, South Carolina, 2005

USGS Publications Warehouse

Harrelson, Larry G.; Addison, Adrian D.

2006-01-01

This study explores the possibility of developing a bank-filtration process to improve water quality in which alluvial deposits serve as a natural sand filter to pretreat water to be used as a secondary drinking-water source in a small piedmont reservoir along the Middle Tyger River near Lyman in Spartanburg County, South Carolina. From January 2004 to September 2005, data from 10 auger borings, 2 sediment cores, 29 ground-penetrating radar transects, and 3 temporary observation wells, and field water-chemistry data were collected and analyzed. These data were collected and used to characterize the lithology, geometry, hydraulic properties, yield potential, and water-chemistry characteristics of the alluvial deposits in the channel and on the right bank of the reservoir. The assessment was undertaken to determine if an adequate amount of water could be withdrawn from the alluvial deposits to sustain a bank-filtration process and to characterize the water chemistry of the surface water and pore water. The heterogeneous alluvial and fill material at the study site--clay, silty clay, clayey sand, fine- to coarse-grained sand, and mica--on the right bank of the Middle Tyger River ranges in thickness from 0.6 to 7 meters, has a calculated horizontal hydraulic conductivity of 1 meter per day, and yields approximately 0.07 liter per second of water. The small calculated horizontal hydraulic conductivity and water yield for these deposits restrict the use of the right bank as a potential bank-filtration site. The coarse-grained alluvial sand deposit in the channel of the Middle Tyger River, however, may be used for a limited bank-filtration process. The discharge during pumping of the channel deposit yielded water at the rate of 1.9 liters per second. The coarse-grained channel deposit is approximately 49 meters wide and 3 meters thick near the dam. At approximately 183 meters upstream from the dam, the channel narrows to roughly 9 meters and the channel deposits thin to approximately 0.1 meter. Slug tests conducted in the channel deposits near the dam produced a calculated horizontal hydraulic conductivity of 60 meters per day. The limited thickness and aerial extent of the coarse-grained channel deposits coupled with large horizontal hydraulic conductivity likely would allow rapid transmission of water and may degrade the effectiveness of some water-chemistry improvements typical of a bank-filtration process. Field water-chemistry data were collected for approximately 1 hour and 45 minutes at 10 to 15 minute intervals to compare the surface-water and pore-water quality in and beneath the channel of the Middle Tyger River. The waterchemistry data indicate that (1) the mean water temperature was higher in surface water (22.5 degrees Celsius) than in pore water (18.5 degrees Celsius), (2) the mean specific conductance was less in surface water (56.9 microsiemens per centimeter at 25 degrees Celsius) than in pore water (125.7 microsiemens per centimeter at 25 degrees Celsius), (3) alkalinity was lower in surface water (22.5 milligrams per liter) than in pore water (44.6 milligrams per liter), and (4) recorded pH values ranged between 6.2 and 6.3 in the surface water and pore water during the sampling period. The flow velocity was orders of magnitude slower in the pore water than in the surface water; therefore, the pore water interacts with the alluvial sediment for a longer period of time producing the variation in water-chemistry data between the two waters.

Cambrian to Devonian evolution of alluvial systems: The sedimentological impact of the earliest land plants

NASA Astrophysics Data System (ADS)

Davies, Neil S.; Gibling, Martin R.

2010-02-01

In present-day alluvial environments, the impact of vegetation on sedimentological processes and deposits is well known. A vegetated catchment may decrease sediment yield, sediment erodibility, Hortonian overland flow, aeolian winnowing of fines, the proportion of sediment transported as bedload, and may increase bank stability, infiltration into substrates, and bed roughness. Vegetation also promotes the production of chemically-weathered clays and soils and the adoption of a meandering style. It is generally understood that, prior to the evolution of terrestrial vegetation during the Early Palaeozoic, ancient alluvial systems were markedly different from modern systems, with many systems adopting a "sheet-braided" style. This understanding has previously informed the interpretations of many Precambrian pre-vegetation alluvial successions, but there has been relatively little work regarding Early Palaeozoic alluvial successions laid down prior to and during the initial colonization of the Earth's surface by plants. A comprehensive review of 144 Cambrian to Devonian alluvial successions documented in published literature was combined with original field data from 34 alluvial successions across Europe and North America. The study was designed to identify changes in alluvial style during the period that vegetation was evolving and first colonizing alluvial environments. An increase in mudrock proportion and sandstone maturity is apparent, along with a decrease in overall sand grain size through the Early Palaeozoic. These trends suggest that primitive vegetation cover promoted the production and preservation of muds from the mid Ordovician onwards and increased the residence time of sand-grade sediment in alluvial systems. The compilation also enables the first stratigraphic occurrence of certain vegetation-dependent sedimentary features to be pinpointed and related to the evolution of specific palaeobotanical adaptations. The first markedly heterolithic alluvial sequences appeared at about the same time as the most primitive terrestrial vegetation in the Ordovician, and prolific pedogenic calcite, charcoal and bioturbated floodplain fines first appeared in the rock record at about the same time as vascular-plant macrofossils became abundant in the late Silurian. Lateral accretion sets in channel deposits appeared near the Silurian-Devonian boundary, at or shortly before the appearance of underground rooting systems, and become progressively more abundant in the record during the Devonian, implying a major expansion of meandering rivers as rooted plants stabilized river banks. Coals become abundant after the development of plant arborescence. The analysis suggests that the evolution of embryophytes had a profound effect on fluvial processes and deposits, and this period of landscape evolution must be considered amongst the most significant environmental and geomorphological changes in Earth history, with profound consequences for all aspects of the Earth system.

Morphological changes of Gumara River channel over 50 years, upper Blue Nile basin, Ethiopia

NASA Astrophysics Data System (ADS)

Abate, Mengiste; Nyssen, Jan; Steenhuis, Tammo S.; Moges, Michael M.; Tilahun, Seifu A.; Enku, Temesgen; Adgo, Enyew

2015-06-01

In response to anthropogenic disturbances, alluvial rivers adjust their geometry. The alluvial river channels in the upper Blue Nile basin have been disturbed by human-induced factors since a longtime. This paper examines channel adjustment along a 38-km stretch of the Gumara River which drains towards Lake Tana and then to the Blue Nile. Over a 50 years period, agriculture developed rapidly in the catchment and flooding of the alluvial plain has become more frequent in recent times. The objectives of this study were to document the changes in channel planform and cross-section of the Gumara River and to investigate whether the changes could have contributed to the frequent flooding or vice versa. Two sets of aerial photographs (1957 and 1980) were scanned, and then orthorectified. Recent channel planform information was extracted from SPOT images of 2006 and Google Earth. Channel planform and bed morphology (vertical changes) were determined for these nearly 50 years period. The vertical changes were determined based on aggradation along a permanent structure, historic information on river cross-sections at a hydrological gauging station, and field observations. The results indicate that the lower reach of Gumara near its mouth has undergone major planform changes. A delta with approx. 1.12 km2 of emerged land was created between 1957 and 1980 and an additional 1 km2 of land has been added between 1980 and 2006. The sinuosity of the river changed only slightly: negatively (-1.1% i.e. meandering decreased) for the period from 1957 to 1980 and positively (+3.0%) for the period 1980-2006. Comparison of cross-sections at the hydrological gauging station showed that the deepest point in the river bed aggraded by 2.91 m for the period 1963-2009. The importance of sediment deposition in the stream and on its banks is related to land degradation in the upper catchment, and to artificial rising of Lake Tana level that creates a backwater effect and sediment deposition in Gumara River. Direct anthropogenic impacts (irrigation activities and building of dykes along the river banks) have contributed to the huge deposition in the river bed. Where the abstraction of water for irrigation is intensive, seepage water through the banks has contributed to river bank failure. In general, this study showed that changes to the planform at the mouth of the river and to the riverbed level are substantial. Moreover, the study indicated that the flood carrying capacity of the Gumara River channel has diminished in recent times.

Intrinsic vs. extrinsic controls on channel evolution in a sub-tropical river, Australia

NASA Astrophysics Data System (ADS)

Daley, James; Croke, Jacky; Thompson, Chris; Cohen, Tim; Macklin, Mark; Sharma, Ashneel

2016-04-01

Palaeohydrological research provides valuable insights to the understanding of short- and long-term fluvial dynamics in response to climate change and tectonic activity. In landscapes where tectonic activity is minimal fluvial archives record long-term changes in sediment and discharge dynamics related to either intrinsic or extrinsic controls. Isolating the relative controls of these factors is an important frontier in this area of research. Advances in geochronology, the acquisition of high resolution topographic data and geomorphological techniques provide an opportunity to assess the relative importance of intrinsic and extrinsic controls on terrace and floodplain formation. This study presents the results of detailed chrono-stratigraphic research in a partly confined river valley in subtropical southeast Queensland. River systems within this region are characterized by high hydrological variability and have a near-ubiquitous compound channel morphology (macrochannel) where Holocene deposits are inset within late Pleistocene terraces. These macrochannels can accommodate floods up to and beyond the predicted 100-year flood. Using single grain optically stimulated luminescence and radiocarbon analyses, combined with high resolution spatial datasets, we demonstrate the nature of fluvial response to major late Quaternary climate change. A large proportion of the valley floor is dominated by terrace alluvium deposited after the Last Glacial Maximum (LGM) (17 - 13 ka) and overlies basal older Pleistocene alluvium. Preliminary results suggest a phase of incision occurred at 10 ka with the formation of the large alluvial trench. The Holocene floodplain is dominated by processes of catastrophic vertical accretion and erosion (cut-and-fill) and oblique accretion at the macrochannel margins. The consistency in ages for the terraces and subsequent incision suggests a uniform network response. Alluvial sediments and channel configuration in this compound and complex landscape represent a discernable response to long-term climate change, high climate variability and extreme weather events.

The Alaska Mineral Resource Assessment Program; background information to accompany geologic and mineral-resource maps of the Cordova and Middleton Island quadrangles, southern Alaska

USGS Publications Warehouse

Winkler, Gary R.; Plafker, George; Goldfarb, R.J.; Case, J.E.

1992-01-01

report summarizes recent results of integrated geological, geochemical, and geophysical field and laboratory studies conducted by the U.S. Geological Survey in the Cordova and Middleton Island 1?x3 ? quadrangles of coastal southern Alaska. Published open-file reports and maps accompanied by descriptive and interpretative texts, tables, diagrams, and pertinent references provide background information for a mineral-resource assessment of the two quadrangles. Mines in the Cordova and Middleton Island quadrangles produced copper and byproduct gold and silver in the first three decades of the 20th century. The quadrangles may contain potentially significant undiscovered resources of precious and base metals (gold, silver, copper, zinc, and lead) in veins and massive sulfide deposits hosted by Cretaceous and Paleogene sedimentary and volcanic rocks. Resources of manganese also may be present in the Paleogene rocks; uranium resources may be present in Eocene granitic rocks; and placer gold may be present in beach sands near the mouth of the Copper River, in alluvial sands within the canyons of the Copper River, and in smaller alluvial deposits underlain by rocks of the Valdez Group. Significant coal resources are present in the Bering River area, but difficult access and structural complexities have discouraged development. Investigation of numerous oil and gas seeps near Katalla in the eastern part of the area led to the discovery of a small, shallow field from which oil was produced between 1902 and 1933. The field has been inactive since, and subsequent exploration and drilling onshore near Katalla in the 1960's and offshore near Middleton Island on the outer continental shelf in the 1970's and 1980's was not successful.

Sediment fingerprinting with long- and short-lived radionuclide tracers in the Root River watershed, southeastern Minnesota

NASA Astrophysics Data System (ADS)

Belmont, P.; Stout, J. C.

2015-12-01

The field of sediment fingerprinting has evolved rapidly over the past decade and is poised to improve our understanding not only of sediment sources, but also the routing of sediment through watersheds. Such information is essential for understanding and modeling human impacts on erosion and sediment routing at the watershed scale. In this study we use long- (Beryllium-10, 10Be) and short-lived (Lead-210 and Cesium-137, 210Pb and 137Cs, respectively) radionuclide tracers associated with suspended sediment to quantify sediment sources and channel-floodplain exchange across a range of watershed scales from 10 km2 to 4500 km2 in in the Root River, southeastern Minnesota, USA. The uppermost quarter of the Root River watershed was glaciated repeatedly during the late Pleistocene and is characterized by low relief agricultural fields and fine textured soils. The remainder of the watershed lies within the driftless area of the upper Midwestern US, which has not been glaciated in at least the past 500,000 years, and is characterized by karst topography, relatively steep hillslopes and bedrock channels that debouch into a wide, aggrading alluvial valley. The structure of the landscape exerts strong control on sediment generation and transport. Geochemical results indicate a highly variable erosion history, with significant variability of 10Be concentrations in source areas (agricultural fields, forested hillslopes, and alluvial floodplains and terraces) and inverted 10Be depth profiles (higher concentrations at depth) in floodplains, suggesting unsteady erosion and significant storage of legacy sediment. Concentrations of 10Be and 210Pb associated with suspended sediment show a systematic disparity in normalized concentrations, indicating that significant storage and re-suspension occurs in both systems as the sediment is routed through the channel-floodplain complex.

An Induced Infiltration and Groundwater Transfer Project to Enhance Recharge in the Lower Mississippi River Valley Alluvial Aquifer: Modeling and Analysis

NASA Astrophysics Data System (ADS)

Rigby, J.; Haugh, C. J.; Barlow, J.

2015-12-01

The Lower Mississippi River Basin is one of the major agricultural production regions in the United States producing over two-thirds of the rice, nearly half of sugarcane produced in the U.S., as well as significant amounts of soybeans, corn, and cotton. While the region experiences over 50 inches of precipitation annually, reaching yield potential for crops requires irrigation. Approximately 75% of crop acres in the alluvial valley are irrigated, and the expectation is that all acreage will eventually be irrigated. Currently over 90% of water for crop irrigation is derived from the shallow alluvial aquifer outpacing net recharge by several million acre-feet per year. This has resulted in severe groundwater declines in Arkansas and an increasingly threatening situation in northwestern Mississippi. In Mississippi, direct injection has received increasing attention as a means of artificial recharge, though water quality remains a concern both for the integrity of the aquifer and efficiency of injection. This project considers the use of pumping wells near major rivers known to be in connection with the aquifer to induce additional infiltration of surface water by steepening local gradients. The pumped water would be transferred by pipeline to areas within the regional cone of depression where it is then injected to enhance groundwater recharge. Groundwater flow modeling with zone budget analysis is used to evaluate the potential for net supply gains from induced infiltration at potential sites along major rivers in the region. The groundwater model will further evaluate the impact of the transfer and direct injection on regional water tables.

Using major ions and δ15N-NO3(-) to identify nitrate sources and fate in an alluvial aquifer of the Baiyangdian lake watershed, North China Plain.

PubMed

Wang, Shiqin; Tang, Changyuan; Song, Xianfang; Yuan, Ruiqiang; Wang, Qinxue; Zhang, Yinghua

2013-07-01

In semi-arid regions, most human activities occur in alluvial fan areas; however, NO3(-) pollution has greatly threatened the shallow groundwater quality. In this paper, δ(15)N-NO3(-) and multi-tracers were used to identify the origin and fate of NO3(-) in groundwater of the Baiyangdian lake watershed, North China Plain. The investigation was conducted in two typical regions: one is the agricultural area located in the upstream of the watershed and another is the region influenced by urban wastewater in the downstream of the watershed. Results indicate that the high NO3(-) concentrations of the upstream shallow groundwater were sourced from fertilizer and manure or sewage leakage, whilst the mixture and denitrification caused the decrease in the NO3(-) concentration along the flow path of the groundwater. In the downstream, industrial and domestic effluent has a great impact on groundwater quality. The contaminated rivers contributed from 45% to 76% of the total recharge to the groundwater within a distance of 40 m from the river. The mixture fraction of the wastewater declined with the increasing distance away from the river. However, groundwater with NO3(-) concentrations larger than 20 mg l(-1) was only distributed in areas near to the polluted river or the sewage irrigation area. It is revealed that the frontier and depression regions of an alluvial fan in a lake watershed with abundant organics, silt and clay sediments have suitable conditions for denitrification in the downstream.

Classification of freshwater ice conditions on the Alaskan Arctic Coastal Plain using ground penetrating radar and TerraSAR-X satellite data

USGS Publications Warehouse

Jones, Benjamin M.; Gusmeroli, Alessio; Arp, Christopher D.; Strozzi, Tazio; Grosse, Guido; Gaglioti, Benjamin V.; Whitman, Matthew S.

2013-01-01

Arctic freshwater ecosystems have responded rapidly to climatic changes over the last half century. Lakes and rivers are experiencing a thinning of the seasonal ice cover, which may increase potential over-wintering freshwater habitat, winter water supply for industrial withdrawal, and permafrost degradation. Here, we combined the use of ground penetrating radar (GPR) and high-resolution (HR) spotlight TerraSAR-X (TSX) satellite data (1.25 m resolution) to identify and characterize floating ice and grounded ice conditions in lakes, ponds, beaded stream pools, and an alluvial river channel. Classified ice conditions from the GPR and the TSX data showed excellent agreement: 90.6% for a predominantly floating ice lake, 99.7% for a grounded ice lake, 79.0% for a beaded stream course, and 92.1% for the alluvial river channel. A GIS-based analysis of 890 surface water features larger than 0.01 ha showed that 42% of the total surface water area potentially provided over-wintering habitat during the 2012/2013 winter. Lakes accounted for 89% of this area, whereas the alluvial river channel accounted for 10% and ponds and beaded stream pools each accounted for <1%. Identification of smaller landscape features such as beaded stream pools may be important because of their distribution and role in connecting other water bodies on the landscape. These findings advance techniques for detecting and knowledge associated with potential winter habitat distribution for fish and invertebrates at the local scale in a region of the Arctic with increasing stressors related to climate and land use change.

Flow resistance and hydraulic geometry in contrasting reaches of a bedrock channel

NASA Astrophysics Data System (ADS)

Ferguson, R. I.; Sharma, B. P.; Hardy, R. J.; Hodge, R. A.; Warburton, J.

2017-03-01

Assumptions about flow resistance in bedrock channels have to be made for mechanistic modeling of river incision, paleoflood estimation, flood routing, and river engineering. Field data on bedrock flow resistance are very limited and calculations generally use standard alluvial-river assumptions such as a fixed value of Manning's n. To help inform future work, we measured how depth, velocity, and flow resistance vary with discharge in four short reaches of a small bedrock channel, one with an entirely rock bed and the others with 20-70% sediment cover, and in the alluvial channel immediately upstream. As discharge and submergence increase in each of the partly or fully alluvial reaches there is a rapid increase in velocity and a strong decline in both n and the Darcy-Weisbach friction factor f. The bare-rock reach follows a similar trend from low to medium discharge but has increasing resistance at higher discharges because of the macroroughness of its rock walls. Flow resistance at a given discharge differs considerably between reaches and is highest where the partial sediment cover is coarsest and most extensive. Apart from the effect of rough rock walls, the flow resistance trends are qualitatively consistent with logarithmic and variable-power equations and with nondimensional hydraulic geometry, but quantitative agreement using sediment D84 as the roughness height is imperfect.

Impact of river water levels on the simulation of stream-aquifer exchanges over the Upper Rhine alluvial aquifer (France/Germany)

NASA Astrophysics Data System (ADS)

Vergnes, Jean-Pierre; Habets, Florence

2018-05-01

This study aims to assess the sensitivity of river level estimations to the stream-aquifer exchanges within a hydrogeological model of the Upper Rhine alluvial aquifer (France/Germany), characterized as a large shallow aquifer with numerous hydropower dams. Two specific points are addressed: errors associated with digital elevation models (DEMs) and errors associated with the estimation of river level. The fine-resolution raw Shuttle Radar Topographic Mission dataset is used to assess the impact of the DEM uncertainties. Specific corrections are used to overcome these uncertainties: a simple moving average is applied to the topography along the rivers and additional data are used along the Rhine River to account for the numerous dams. Then, the impact of the river-level temporal variations is assessed through two different methods based on observed rating curves and on the Manning formula. Results are evaluated against observation data from 37 river-level points located over the aquifer, 190 piezometers, and a spatial database of wetlands. DEM uncertainties affect the spatial variability of the stream-aquifer exchanges by inducing strong noise and unrealistic peaks. The corrected DEM reduces the biases between observations and simulations by 22 and 51% for the river levels and the river discharges, respectively. It also improves the agreement between simulated groundwater overflows and observed wetlands. Introducing river-level time variability increases the stream-aquifer exchange range and reduces the piezometric head variability. These results confirm the need to better assess river levels in regional hydrogeological modeling, especially for applications in which stream-aquifer exchanges are important.

Groundwater hydrology and estimation of horizontal groundwater flux from the Rio Grande at selected locations in Albuquerque, New Mexico, 2003-9

USGS Publications Warehouse

Rankin, Dale R.; McCoy, Kurt J.; More, Geoff J.M.; Worthington, Jeffrey A.; Bandy-Baldwin, Kimberly M.

2013-01-01

The Albuquerque, New Mexico, area has two principal sources of water: groundwater from the Santa Fe Group aquifer system and surface water from the San Juan-Chama Diversion Project. From 1960 to 2002, groundwater withdrawals from the Santa Fe Group aquifer system have caused water levels to decline more than 120 feet in some places within the Albuquerque area, resulting in a great deal of interest in quantifying the river-aquifer interaction associated with the Rio Grande. In 2003, the U.S. Geological Survey in cooperation with the Bureau of Reclamation, the Middle Rio Grande Endangered Species Collaborative Program, and the U.S. Army Corps of Engineers began a detailed characterization of the hydrogeology of the Rio Grande riparian corridor in the Albuquerque, New Mexico, area to provide hydrologic data and enhance the understanding of rates of water leakage from the Rio Grande to the alluvial aquifer, groundwater flow through the aquifer, and discharge of water from the aquifer to the riverside drains. A simple conceptual model of flow indicates that the groundwater table gently slopes from the Rio Grande towards riverside drains and the outer boundaries of the inner valley. Water infiltrating from the Rio Grande initially moves vertically below the river, but, as flow spreads farther into the Rio Grande inner valley alluvial aquifer, flow becomes primarily horizontal. The slope of the water-table surface may be strongly controlled by the riverside drains and influenced by other more distal hydrologic boundary conditions, such as groundwater withdrawals by wells. Results from 35 slug tests performed in the Rio Grande inner valley alluvial aquifer during January and February 2009 indicate that hydraulic-conductivity values ranged from 5 feet per day to 160 feet per day with a median hydraulic-conductivity for all transects of 40 feet per day. Median annual horizontal hydraulic gradients in the Rio Grande inner valley alluvial aquifer ranged from 0.011 to 0.002. Groundwater fluxes through the alluvial aquifer calculated by using median slug-test results (qmslug) and Darcy's law ranged from about 0.1 feet per day to about 0.7 feet per day. Groundwater fluxes calculated by using the Suzuki-Stallman method (qmheat) ranged from 0.52 feet per day to 0.23 feet per day. Results from the Darcy's law and Suzuki-Stallman flux calculations were compared to discharge measured in riverside drains on both sides of the river north of the Montaño Bridge on February 26, 2009. Flow in the Corrales Riverside Drain increased by 1.4 cubic feet per second from mile 2 to mile 4, about 12 cubic feet per day per linear foot of drain. Flow in the Albuquerque Riverside Drain increased by 15 cubic feet per second between drain miles 0 and 3, about 82 cubic feet per day per linear foot of drain. The flux of water from the river to the aquifer was calculated to be 2.2 cubic feet per day per linear foot of river by using the median qmslug of 0.09 feet per day at Montaño transects west of the river. The total flux was calculated to be 6.0 cubic feet per day per linear foot of river by using the mean(qmheat of 0.24 feet per day for the Montaño transects west of the river. Assuming the Corrales Riverside Drain intercepted all of this flow, the qmslug or qmheat fluxes account for 18 to 50 percent, respectively, of the increase of flow in the drain. The flux of water from the river to the aquifer was calculated to be 15 cubic feet per day per linear foot of river by using the median qmslug of 0.30 feet per day at the Montaño transects east of the river. The flux of water from the river to the aquifer was calculated to be 17 cubic feet per day per linear foot of river by using the mean flux calculated from the Suzuki-Stallman method for the Montaño East transects of 0.34 feet per day. Assuming the Albuquerque Riverside Drain intercepted all this flow, the qmslug or (qmheat fluxes would only account for 18 to 21 percent, respectively, of the increase in flow in the drain. The comparison of these results with those of previous investigations suggests that calculated flux through the Rio Grande inner valley alluvial aquifer is strongly scale dependent and that the thickness of aquifer through which river water flows may be greater than indicated by the vertical temperature profiles.

Analysis of managed aquifer recharge for retiming streamflow in an alluvial river

NASA Astrophysics Data System (ADS)

Ronayne, Michael J.; Roudebush, Jason A.; Stednick, John D.

2017-01-01

Maintenance of low flows during dry periods is critical for supporting ecosystem function in many rivers. Managed aquifer recharge is one method that can be used to augment low flows in rivers that are hydraulically connected to an alluvial groundwater system. In this study, we performed numerical modeling to evaluate a managed recharge operation designed to retime streamflow in the South Platte River, northeastern Colorado (USA). Modeling involved the simulation of spatially and temporally variable groundwater-surface water exchange, as well as streamflow routing in the river. Periodic solutions that incorporate seasonality were developed for two scenarios, a natural base case scenario and an active management scenario that included groundwater pumping and managed recharge. A framework was developed to compare the scenarios by analyzing changes in head-dependent inflows and outflows to/from the aquifer, which was used to interpret the simulated impacts on streamflow. The results clearly illustrate a retiming of streamflow. Groundwater pumping near the river during winter months causes a reduction in streamflow during those months. Delivery of the pumped water to recharge ponds, located further from the river, has the intended effect of augmenting streamflow during low-flow summer months. Higher streamflow is not limited to the target time period, however, which highlights an inefficiency of flow augmentation projects that rely on water retention in the subsurface.

Tree regeneration by seed in bottomland hardwood forests: A review

USGS Publications Warehouse

Kroschel, Whitney A.; King, Sammy L.; Keim, Richard F.

2016-01-01

Bottomland hardwood forests (BLH) are found in temperate, humid regions of the southeastern US, primarily on alluvial floodplains adjacent to rivers. Altered hydrology in rivers and floodplains has caused changes in stand development and species composition of BLHs. We hypothesize that the driving mechanisms behind these changes are related to the regeneration process because of the complexity of recruitment and the vulnerability of species at that age in development. Here we review the state of our understanding regarding BLH regeneration, and identify potential bottlenecks throughout the stages of seed production, seed dispersal, germination, establishment, and survival. Our process-level understanding of regeneration by seed in BLHs is rudimentary, thus limiting our ability to predict the effects of hydrologic alterations on species composition. By focusing future research on the appropriate stages of regeneration, we can better understand the sources of forest-community transitions across the diverse range of BLH systems.

A Day in the Life of the Suwannee River: Lagrangian Sampling of Process Rates Along the River Continuum

NASA Astrophysics Data System (ADS)

Cohen, M. J.; Hensley, R. T.; Spangler, M.; Gooseff, M. N.

2017-12-01

A key organizing idea in stream ecology is the river continuum concept (RCC) which makes testable predictions about network-scale variation in metabolic and community attributes. Using high resolution (ca. 0.1 Hz) Lagrangian sampling of a wide suite of solutes - including nitrate, fDOM, dissolved oyxgen and specific conductance, we sampled the river continuum from headwaters to the sea in the Suwannee River (Florida, USA). We specifically sought to test two predictions that follow from the RCC: first, that changes in metabolism and hydraulics lead to progressive reduction in total N retention but greater diel variation with increasing stream order; and second, that variation in metabolic and nutrient processing rates is larger across stream orders than between low order streams. In addition to providing a novel test of theory, these measurements enabled new insights into the evolution of water quality through a complex landscape, in part because main-stem profiles were obtained for both high and historically low flow conditions. We observed strong evidence of metabolism and nutrient retention at low flow. Both the rate of uptake velocity and the mass retention per unit area declined with increasing stream order, and declined dramatically at high flow. Clear evidence for time varying retention (i.e., diel variation) was observed at low flow, but was masked or absent at high flow. In this geologically complex river - with alluvial, spring-fed, and blackwater headwater streams - variation across low-order streams was large, suggesting the presence of many river continuua across the network. This application of longitudinal sampling and inference underscores the utility of changing reference frames to draw new insights, but also highlights some of the challenges that need to be considered and, where possible, controlled.

Development and maintenance of a telescoping debris flow fan in response to human-induced fan surface channelization, Chalk Creek Valley Natural Debris Flow Laboratory, Colorado, USA

NASA Astrophysics Data System (ADS)

Wasklewicz, T.; Scheinert, C.

2016-01-01

Channel change has been a constant theme throughout William L. Graf's research career. Graf's work has examined channel changes in the context of natural environmental fluctuations, but more often has focused on quantifying channel change in the context of anthropogenic modifications. Here, we consider how channelization of a debris flows along a bajada has perpetuated and sustained the development of 'telescoping' alluvial fan. Two-dimensional debris-flow modeling shows the importance of the deeply entrenched channelized flow in the development of a telescoping alluvial fan. GIS analyses of repeat (five different debris flows), high-resolution (5 cm) digital elevation models (DEMs) generated from repeat terrestrial laser scanning (TLS) data elucidate sediment and topographic dynamics of the new telescoping portion of the alluvial fan (the embryonic fan). Flow constriction from channelization helps to perpetuate debris-flow runout and to maintain the embryonic fan and telescoping nature of the alluvial fan complex. Embryonic fan development, in response to five debris flows, proceeds with a major portion of the flows depositing on the southern portion of the embryonic fan. The third through the fifth debris flows also begin to shift some deposition to the northern portion of the embryonic. The transfer of sediment from a higher portion of the embryonic fan to a lower portion continues currently on the embryonic fan. While channelized flow has been shown to be critical to the maintenance of the telescoping fan, the flow constriction has led to higher than background levels of sediment deposition in Chalk Creek, a tributary of the Arkansas River. A majority of the sediment from each debris flow is incorporated into Chalk Creek as opposed to being stored on the embryonic fan.

Conjunctive-use optimization model of the Mississippi River Valley alluvial aquifer of Southeastern Arkansas

USGS Publications Warehouse

Czarnecki, John B.; Clark, Brian R.; Stanton, Gregory P.

2003-01-01

The Mississippi River Valley alluvial aquifer is a water-bearing assemblage of gravels and sands that underlies about 32,000 square miles of Missouri, Kentucky, Tennessee, Mississippi, Louisiana, and Arkansas. Because of the heavy demands placed on the aquifer, several large cones of depression have formed in the potentiometric surface, resulting in lower well yields and degraded water quality in some areas. A ground-water flow model of the alluvial aquifer was previously developed for an area covering 3,826 square miles, extending south from the Arkansas River into the southeastern corner of Arkansas, parts of northeastern Louisiana, and western Mississippi. The flow-model results indicated that continued ground-water withdrawals at rates commensurate with those of 1997 could not be sustained indefinitely without causing water levels to decline below half the original saturated thickness of the aquifer. Conjunctive-use optimization modeling was applied to the flow model of the alluvial aquifer to develop withdrawal rates that could be sustained relative to the constraints of critical ground-water area designation. These withdrawal rates form the basis for estimates of sustainable yield from the alluvial aquifer and from rivers specified within the alluvial aquifer model. A management problem was formulated as one of maximizing the sustainable yield from all ground-water and surface-water withdrawal cells within limits imposed by plausible withdrawal rates, and within specified constraints involving hydraulic head and streamflow. Steady-state conditions were selected because the maximized withdrawals are intended to represent sustainable yield of the system (a rate that can be maintained indefinitely).One point along the Arkansas River and one point along Bayou Bartholomew were specified for obtaining surface-water sustainable-yield estimates within the optimization model. Streamflow constraints were specified at two river cells based on average 7-day low flows with 10-year recurrence intervals. Sustainable-yield estimates were affected by the allowable upper limit on withdrawals from wells specified in the optimization model. Withdrawal rates were allowed to increase to 200 percent of the withdrawal rate in 1997. As the overall upper limit is increased, the sustainable yield generally increases. Tests with the optimization model show that without limits on pumping, wells adjacent to sources of water, such as large rivers, would have optimal withdrawal rates that were orders of magnitude larger than rates corresponding to those of 1997. Specifying an upper withdrawal limit of 100 percent of the 1997 withdrawal rate, the sustainable yield from ground water for the entire study area is 70.3 million cubic feet per day, which is about 96 percent of the amount withdrawn in 1997 (73.5 million cubic feet per day). If the upper withdrawal limit is increased to 150 percent of the 1997 withdrawal rate, the sustainable yield from ground water for the entire study area is 80.6 million cubic feet per day, which is about 110 percent of the amount withdrawn in 1997. If the upper withdrawal limit is increased to 200 percent of the 1997 withdrawal rate, the sustainable yield from ground water for the entire study area is 110.2 million cubic feet per day, which is about 150 percent of the amount withdrawn in 1997. Total sustainable yield from the Arkansas River and Bayou Bartholomew is about 4,900 million cubic feet per day, or about 6,700 percent of the amount of ground-water withdrawn in 1997. The large, sustainable yields from surface water represent a potential source of water that could supplement ground water and meet the total water demand. Unmet demand (defined as the difference between the optimized withdrawal rate or sustainable yield, and the anticipated demand) was calculated using different demand rates based on multiples of the 1997-withdrawal rate. Assuming that demand is the 1997 withdrawal rate, and that sustainable-

Geologic map of the Orchard 7.5' quadrangle, Morgan County, Colorado

USGS Publications Warehouse

Berry, Margaret E.; Slate, Janet L.; Hanson, Paul R.; Brandt, Theodore R.

2015-01-01

The Orchard 7.5' quadrangle is located along the South Platte River corridor on the semi-arid plains of eastern Colorado, and contains surficial deposits that record alluvial, eolian, and hillslope processes that have operated through environmental changes from the Pleistocene to the present. The South Platte River, originating high in the Colorado Front Range, has played a major role in shaping the geology of the quadrangle, which is situated downstream of where the last of the major headwater tributaries (St. Vrain, Big Thompson, and Cache la Poudre) join the river. Recurrent glaciation (and deglaciation) of basin headwaters affected river discharge and sediment supply far downstream, influencing alluvium deposition and terrace formation in the Orchard quadrangle. Kiowa and Bijou Creeks, unglaciated tributaries originating east of the Front Range also have played a major role by periodically delivering large volumes of sediment to the river during flood events, which may have temporarily dammed the river. Eolian sand deposits of the Greeley (north of river) and Fort Morgan (south of river) dune fields cover much of the quadrangle and record past episodes of sand mobilization during times of drought. With the onset of irrigation during historic times, the South Platte River has changed from a broad, shallow, and sandy braided river with highly seasonal discharge to a much narrower, deeper river with braided-meandering transition morphology and more uniform discharge. Along this reach, the river has incised into Upper Cretaceous Pierre Shale, which, although buried by alluvial deposits in Orchard quadrangle, is locally exposed downstream along the South Platte River bluff near the Bijou Creek confluence, in some of the larger draws, and along Wildcat Creek.

The quality of our Nation's waters: water quality in the Mississippi embayment-Texas coastal uplands aquifer system and Mississippi River Valley alluvial aquifer, south-central United States, 1994-2008

USGS Publications Warehouse

Kingsbury, James A.; Barlow, Jeannie R.; Katz, Brian G.; Welch, Heather L.; Tollett, Roland W.; Fahlquist, Lynne S.

2015-01-01

About 8 million people rely on groundwater from the Mississippi embayment—Texas coastal uplands aquifer system for drinking water. The Mississippi River Valley alluvial aquifer also provides drinking water for domestic use in rural areas but is of primary importance to the region as a source of water for irrigation. Irrigation withdrawals from this aquifer are among the largest in the Nation and play a key role in the economy of the area, where annual crop sales total more than $7 billion. The reliance of the region on both aquifers for drinking water and irrigation highlights the importance of long-term management to sustain the availability and quality of these resources.

Investigations on alluvial deposits through borehole stratigraphy, radiocarbon dating and passive seismic technique (Carnic Alps, NE Italy)

NASA Astrophysics Data System (ADS)

Viero, Alessia; Marchi, Lorenzo; Cavalli, Marco; Crema, Stefano; Fontana, Alessandro; Mozzi, Paolo; Venturini, Corrado

2016-04-01

Alluvial sediment investigations provide fundamental tools to infer the processes that control geomorphological evolution of mountain environments. By analyzing sediment stratigraphy in depth, it is possible to retrieve the source, the geology, the time of deposition, the relative distance travelled by material as well as to distinguish among different type of transport (i.e., gravitational, fluvial or glacial). In this work, we present a combination of log stratigraphy, radiocarbon dating and geophysical surveys carried out on the valley floor of the But River (Carnic Alps, North East Italy). The But River basin drains an area of 326 km2 with a range in elevation from 2769 to 323 m a.s.l.; the bedrock mainly consists of carbonates and quartz arenites with minor inclusions of effusive rocks. After Pleistocene the gravitational deposits from mountain slopes have impounded the But River several times. In particular, we analyzed a sector of the upper portion of the But valley close to the confluence of the Moscardo Torrent, frequently affected by debris flows. A borehole was drilled in the But River floodplain, at the intersection with the Moscardo Torrent alluvial fan, down to a depth of 80 m. The analysis of the core samples allowed discerning three sedimentary levels rich in clay and organic materials, which testify the presence of small dam lakes, originated from the Moscardo debris-flow deposits. Three samples of wood and plant debris were collected from 13, 14 and 23 m of depth, respectively. They were analyzed through radiocarbon dating in order to determine the age of the lakes and, thus, to infer the activity of the debris flows building the Moscardo cone. The calibrated ages of the 3 samples are close to the younger limit of the radiocarbon method indicating a fast aggradation of the valley floor, starting from a period ranging between 1450 - 1632 AD. Historical maps and documents confirm the presence of the lakes until 19th century and they permit to assess their extent and the maximum depths. Two passive seismic campaigns were carried out near the borehole site and along the But valley at different elevations. The aim was to investigate the depth of the buried bedrock and therefore to indirectly characterize the thickness of alluvial deposits. We calibrated the fundamental frequency of each site by constraining average shear velocity of the alluvial sediments close to the borehole site with known stratigraphy. Eight HVSR (Horizontal to Vertical Spectral Ratio, Nakamura, 1989) were carried out, and thus a first sketch of the buried valley floor along a longitudinal profile of about 5 km was depicted. The values of the derived bedrock depth allow to quantify the differences in thickness between the alluvial deposits and the Moscardo Torrent fan deposits. This information helps to address the contribution of the debris-flow processes in damming the upper But River during the last five centuries. The results confirm the role of debris-flow deposits from the Moscardo Torrent in shaping the morphology of the valley floor of But River and show suitability of an integrated approach, encompassing log stratigraphy, geophysical surveys and analysis of historical documents, for gaining insights on the evolution of alpine valleys. Reference Nakamura, Y., 1989. A method for dynamic characteristic estimation of subsurface using microtremor on the ground surface. Quarterly Report of Railway Technical Research Institute, 30(1): 25-33.

Development of a stream-aquifer numerical flow model to assess river water management under water scarcity in a Mediterranean basin.

PubMed

Mas-Pla, Josep; Font, Eva; Astui, Oihane; Menció, Anna; Rodríguez-Florit, Agustí; Folch, Albert; Brusi, David; Pérez-Paricio, Alfredo

2012-12-01

Stream flow, as a part of a basin hydrological cycle, will be sensible to water scarcity as a result of climate change. Stream vulnerability should then be evaluated as a key component of the basin water budget. Numerical flow modeling has been applied to an alluvial formation in a small mountain basin to evaluate the stream-aquifer relationship under these future scenarios. The Arbúcies River basin (116 km(2)) is located in the Catalan Inner Basins (NE Spain) and its lower reach, which is related to an alluvial aquifer, usually becomes dry during the summer period. This study seeks to determine the origin of such discharge losses whether from natural stream leakage and/or induced capture due to groundwater withdrawal. Our goal is also investigating how discharge variations from the basin headwaters, representing potential effects of climate change, may affect stream flow, aquifer recharge, and finally environmental preservation and human supply. A numerical flow model of the alluvial aquifer, based on MODFLOW and especially in the STREAM routine, reproduced the flow system after the usual calibration. Results indicate that, in the average, stream flow provides more than 50% of the water inputs to the alluvial aquifer, being responsible for the amount of stored water resources and for satisfying groundwater exploitation for human needs. Detailed simulations using daily time-steps permit setting threshold values for the stream flow entering at the beginning of the studied area so surface discharge is maintained along the whole watercourse and ecological flow requirements are satisfied as well. The effects of predicted rainfall and temperature variations on the Arbúcies River alluvial aquifer water balance are also discussed from the outcomes of the simulations. Finally, model results indicate the relevance of headwater discharge management under future climate scenarios to preserve downstream hydrological processes. They also point out that small mountain basins could be self-sufficient units so long as the response of the main hydrological components to external forces that produce water scarcity, as climate change or human pressures, is appropriately considered in water resource planning. Copyright © 2012 Elsevier B.V. All rights reserved.

The role of bedrock in creating habitat in temperate watercourses

NASA Astrophysics Data System (ADS)

Entwistle, N. S.; Heritage, G. L.; Milan, D. J.

2016-12-01

Bedrock influenced rivers are a relatively common yet little studied river type across temperate regions, occurring predominantly in upland areas and in areas where isostatic rebound has promoted rapid watercourse downcutting through resistant bedrock. The presence of bedrock in the bed and banks exerts a major influence on channel development, controlling local flow hydraulics and subsequently influencing in-channel and valley bottom sedimentary feature development. This paper summarises extensive field audit evidence of bedrock influenced features on watercourses in the UK to characterise the diverse morphology of bedrock influenced channels and reviews the bedrock induced hydraulic influences on their development and maintenance. Such features include bedrock waterfalls, steps, rapids and cascades and associated alluvial deposits forming lee bars, bedrock obstruction bars, plunge pool bars and fine sediment drapes and veneers. Bedrock influence on valley bottom features is also reviewed and a functional typology is developed for this river type based on the feature assemblage and degree of bedrock/alluvial influence.

Designing the Alluvial Riverbeds in Curved Paths

NASA Astrophysics Data System (ADS)

Macura, Viliam; Škrinár, Andrej; Štefunková, Zuzana; Muchová, Zlatica; Majorošová, Martina

2017-10-01

The paper presents the method of determining the shape of the riverbed in curves of the watercourse, which is based on the method of Ikeda (1975) developed for a slightly curved path in sandy riverbed. Regulated rivers have essentially slightly and smoothly curved paths; therefore, this methodology provides the appropriate basis for river restoration. Based on the research in the experimental reach of the Holeška Brook and several alluvial mountain streams the methodology was adjusted. The method also takes into account other important characteristics of bottom material - the shape and orientation of the particles, settling velocity and drag coefficients. Thus, the method is mainly meant for the natural sand-gravel material, which is heterogeneous and the particle shape of the bottom material is very different from spherical. The calculation of the river channel in the curved path provides the basis for the design of optimal habitat, but also for the design of foundations of armouring of the bankside of the channel. The input data is adapted to the conditions of design practice.

Hydrologic Linkages Between Floodplain Wetlands and Adjacent Agricultural Lands

NASA Astrophysics Data System (ADS)

Matteson, C.; Jackson, C. R.; Wilde, S. B.; Batzer, D.; Shelton, J.; Jeffers, J. B.

2017-12-01

Depending on wetland position relative to dominant flow pathways, wetlands can provide biogeochemical processing and water quality improvement in agricultural settings, particularly with respect to nutrients. Here we evaluate field-to-stream water quality gradients across a forested alluvial swamp and through a ditched wetland swale on the same site. During 2016 and 2017, water samples collected on a farm from shallow piezometers and surface water were analyzed for total oxidized nitrogen (TOxN), total phosphorus (TP), and microbial abundance. A 54-acre alluvial swamp borders the northern side of the study farm. Toeslope nutrient concentrations in shallow groundwater and surfacewater are elevated relative to background levels, with median values of 13.25 mg/l/TOxN and 47.60 µg/l/TP. Shallow groundwater and surfacewater concentrations are substantially lower only a few meters into the floodplain wetland and lower still (0.13 mg/l/TOxN and 29.67 µg/l/TP) at discharge points to an adjacent creek. Across the farm, an 18-acre wetland swale has been ditched, drained, and cropped. TOxN levels entering and exiting the ditched swale do not mitigate as efficiently, median values of 3.91 mg/l/TOxN reduce to 1.45 mg/l/TOxN, while TP input and reduction exceed the alluvial swamp by starting at 141.67 µg/l/TP at the inflow and discharging into a large river at 57.40 µg/l/TP. Microbial communities in seeps and surfacewater also vary systematically with geographic position. Higher proportions of Cyanobacteria, Turbidity indicators, and Diatom communities are observed in the ditched swale, and input areas of the alluvial swamp. ANOVA tests of TOxN (P<0.001) and TP (P=0.9) change across the alluvial swamp suggest effective processing of TOxN. While P values for TOxN and TP in the ditched swale, yield P=0.9 for TOxN and P=1.0 for TP indicating reduced efficiency of mitigation. Though values of both TOxN and TP do decrease before discharge into the river, they are not statistically significant and still greater values than the alluvial swamp. Dissipation of microbial indicators shows pollution mitigation further into the alluvial swamp. Though pollutant additions have been similar into both wetland types, water quality improvements are distinct in the alluvial swamp.

Anthropic signatures in alluvium of the Upper Little Tennessee River valley, Southern Blue Ridge Mountains, USA

Treesearch

Lixin Wang; David S. Leigh

2015-01-01

Human activities have become important influences on the fluvial systems of eastern North America since post-colonial settlement. This research identifies post-settlement anthropic signatures in alluvial sediments in the Upper Little Tennessee River, USA. Agricultural and mining activities were scattered and discontinuous in this relatively remote region of...

Abundance and production of riparian trees in the lowland floodplain of the Queets River, Washington.

Treesearch

Estelle V. Balian; Robert J. Naiman

2005-01-01

Riparian zones associated with alluvial rivers are spatially dynamic, forming distinct vegetative mosaics that exhibit sharp contrasts in structure and processes related to the underlying biophysical template. The productivity of riparian plants, especially trees, influences streamside community characteristics as, well as the forms and fluxes of organic matter to...

Bedrock channel reaches morphology: examples from the Northern Marche Region (Italy)

NASA Astrophysics Data System (ADS)

Tiberi, V.; di Agostino, V.; Troiani, F.; Nesci, O.; Savelli, D.

2009-04-01

The Northern Marche rivers, on account of a significant variability of their catchment geology, geodynamics and geomorphology, can be regarded as excellent natural laboratories for the study of the morphology, dynamics and evolution of bedrock channel reaches. Hence a geomorphologic study has been carried on in order to map and describe -from qualitative and quantitative point of view- some bedrock channel types of this area, to detect morphological controls at different scales (from the local scale up to the catchment one), and to assess human perturbations on the drainage systems. The study is based on detailed field surveying concerning channel shape and dynamics, floodplain configurations, slope geomorphologic processes, bedrock structure and composition. In addiction, a good aero photograph documentation dating back to the 1955 allowed a reliable reconstruction of the main evolution trends of bedrock channel reaches in the latest past. In the reported rivers the bedrock channel reaches vary in length from a few tens to hundreds of meters, and alternate with alluvial and mixed bedrock-alluvial channel reaches. In many cases specific numerical relations among geometric parameters of bedrock channels have been discovered and some similarities in both morphology and dynamics of rock-cut channels with alluvial channel reaches have been pointed out. Specifically, with regard of their morphologic arrangement, geometric parameters, and flow dynamics several bedrock channels are quite similar to step pool channels found along gravelly channel reaches. Nonetheless, along a given segment of the hydrographical network where an individual alluvial-channel pattern (e.g. a wandering) is found both upstream and downstream a rock-cut channel reach, the occurrence of this latter (e.g. planar bedrock-floored channel) simply breaks the along-stream continuity of the alluvial-bed morphology.

Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in Central Oklahoma

USGS Publications Warehouse

Adams, G.P.; Rea, Alan; Runkle, D.L.

1997-01-01

ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of of hydraulic conductivity, recharge, and ground-water level elevation contours for the alluvial and terrace deposits along the alluvial and terrace deposits along the North Canadian River from Canton Lake to Lake Overholser in central Oklahoma. Ground water in approximately 400 square miles of Quaternary-age alluvial and terrace aquifer is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. The aquifer consists of clay, silt, sand, and gravel. Sand-sized sediments dominate the poorly sorted, fine to coarse, unconsolidated quartz grains in the aquifer. The hydraulically connected alluvial and terrace deposits unconformably overlie Permian-age formations. The aquifer is overlain by a layer of wind-blown sand in parts of the area. Most of the lines in the aquifer boundary, hydraulic conductivity, and recharge data sets were extracted from published digital surficial geology data sets based on a scale of 1:250,000. The ground-water elevation contours and some of the lines for the aquifer boundary, hydraulic conductivity, and recharge data sets were digitized from a ground-water modeling report about the aquifer published at a scale of 1:250,000. The hydraulic conductivity values and recharge rates also are from the ground-water modeling report. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

Are North Slope surface alluvial fans pre-Holocene relicts?

USGS Publications Warehouse

Reimnitz, Erk; Wolf, Stephen C.

1998-01-01

The surface morphology of the northern slope of the Brooks Range (North Slope) from the Canning River, Alaska, eastward is dominated by a series of large alluvial fans and braided streams floored by coarse alluvium. On the basis of our studies, we conclude that the fans are not prograding now nor have they been prograding at any time during the Holocene. During the latest transgression and the following sea-level highstand, the North Slope depositional environment and climate probably differed greatly from the present ones.

Ground-water levels in and pumpage from the alluvial aquifer at Louisville, Kentucky, May 1989-May 1991

USGS Publications Warehouse

Unthank, Michael D.

1995-01-01

Water-level data have been collected in the alluvial aquifer at Louisville, Ky., by the U.S. Geological Survey since 1943. Interpretations of these data are published periodically to update the record and help local officials manage this ground-water supply. Maps and hydrographs are presented on two sheets to aid in the interpretation of water-level changes for the period May 1989-May 1991. The altitude of the water table in the alluvial aquifer has increased as much as 5 feet in some areas during the 2-year period of May 1989-May 1991. Hydrographs for obser- vation wells throughout the alluvial aquifer show that water levels fluctuate seasonally and in response to wet and dry periods; overall, the water- level trend has been upward in recent years. Water levels in the downtown area are affected by the pumping of ground water to heat and cool several buildings in the area. Ground-water contour maps show induced infiltration of water from the Ohio River to the alluvial aquifer in downtown Louisville as a result of the ground-water pumping.

Geology and Geophysical Surveys to Infer the Structure of the Upper San Pedro River Basin, Sonora, Mexico for Use in a Ground-Water-Flow Model

NASA Astrophysics Data System (ADS)

Pool, D.; Gray, F.; Callegary, J. B.

2005-05-01

Data on geology and geophysics in the San Pedro River Basin in Sonora, Mexico were combined to develop a three-dimensional conceptual model of the alluvial-fill aquifer in the basin that is being used to construct a regional ground-water-flow model. In Mexico, the headwater region of the river encompasses approximately 1,800 square kilometers of an ungaged catchment system. This feeds a 58 kilometer-long series of intermittent and perennial stream reaches in the United States that extend from just north of the international border to the town of St. David, Arizona. The river forms part of a north-south riparian corridor that provides habitat for more than 100 resident and 250 migratory bird species. Ground water in the basin is used extensively on both sides of the border and information on basin structure and composition will help to address questions regarding ground- and surface-water sustainability and planning. Interpretations of bedrock and alluvial-fill geometry indicate that a significant portion of the catchment area in Mexico is underlain by bedrock composed of highly indurated (compacted) Cretaceous sedimentary, volcanic, volcano-sedimentary, and granitic intrusive rocks. Aeromagnetic surveys were used to estimate depth to bedrock underlying alluvial sediments. Satellite photographs, older geologic maps, and recent field observations were used to delineate the boundaries between bedrock and alluvium. About 655 square kilometers, or 36 percent, of the Mexican portion of the river basin is underlain by alluvial fill. In the southern part of the study area, detailed information on thickness and composition of subsurface layers to depths of 500 meters was derived from drill logs. An extensive network of vertical electrical soundings covering much of the central part of the basin allowed for estimates of the location and thickness of clay layers that are confining units within the aquifer system. Across much of the area, the thickness of the silt and confining units was difficult to determine because of problems in distinguishing between these layers and underlying, electrically-conductive Cretaceous siltstone and mudstone. In general, two hydraulically connected sub-basins were identified: one in the southern part of the study area and one in the northern part.

Characterizing the spatiotemporal variability of groundwater levels of alluvial aquifers in different settings using drought indices

NASA Astrophysics Data System (ADS)

Haas, Johannes Christoph; Birk, Steffen

2017-05-01

To improve the understanding of how aquifers in different alluvial settings respond to extreme events in a changing environment, we analyze standardized time series of groundwater levels (Standardized Groundwater level Index - SGI), precipitation (Standardized Precipitation Index - SPI), and river stages of three subregions within the catchment of the river Mur (Austria). Using correlation matrices, differences and similarities between the subregions, ranging from the Alpine upstream part of the catchment to its shallow foreland basin, are identified and visualized. Generally, river stages exhibit the highest correlations with groundwater levels, frequently affecting not only the wells closest to the river, but also more distant parts of the alluvial aquifer. As a result, human impacts on the river are transferred to the aquifer, thus affecting the behavior of groundwater levels. Hence, to avoid misinterpretation of groundwater levels in this type of setting, it is important to account for the river and human impacts on it. While the river is a controlling factor in all of the subregions, an influence of precipitation is evident too. Except for deep wells found in an upstream Alpine basin, groundwater levels show the highest correlation with a precipitation accumulation period of 6 months (SPI6). The correlation in the foreland is generally higher than that in the Alpine subregions, thus corresponding to a trend from deeper wells in the Alpine parts of the catchment towards more shallow wells in the foreland. Extreme events are found to affect the aquifer in different ways. As shown with the well-known European 2003 drought and the local 2009 floods, correlations are reduced under flood conditions, but increased under drought. Thus, precipitation, groundwater levels and river stages tend to exhibit uniform behavior under drought conditions, whereas they may show irregular behavior during floods. Similarly, correlations are found to be weaker in years with little snow as compared with those with much snow. This is in agreement with typical aquifer response times over 1 month, suggesting that short events such as floods will not affect much of the aquifer, whereas a long-term event such as a drought or snow-rich winter will. Splitting the time series into periods of 12 years reveals a tendency towards higher correlations in the most recent time period from 1999 to 2010. This time period also shows the highest number of events with SPI values below -2. The SGI values behave in a similar way only in the foreland aquifer, whereas the investigated Alpine aquifers exhibit a contrasting behavior with the highest number of low SGI events in the time before 1986. This is a result of overlying trends and suggests that the groundwater levels within these subregions are more strongly influenced by direct human impacts, e.g., on the river, than by changes in precipitation. Thus, direct human impacts must not be ignored when assessing climate change impacts on alluvial aquifers situated in populated valleys.

Facies analysis, depositional environments and paleoclimate of the Cretaceous Bima Formation in the Gongola Sub - Basin, Northern Benue Trough, NE Nigeria

NASA Astrophysics Data System (ADS)

Shettima, B.; Abubakar, M. B.; Kuku, A.; Haruna, A. I.

2018-01-01

Facies analysis of the Cretaceous Bima Formation in the Gongola Sub -basin of the Northern Benue Trough northeastern Nigeria indicated that the Lower Bima Member is composed of alluvial fan and braided river facies associations. The alluvial fan depositional environment dominantly consists of debris flow facies that commonly occur as matrix supported conglomerate. This facies is locally associated with grain supported conglomerate and mudstone facies, representing sieve channel and mud flow deposits respectively, and these deposits may account for the proximal alluvial fan region of the Lower Bima Member. The distal fan facies were represented by gravel-bed braided river system of probably Scot - type model. This grade into sandy braided river systems with well developed floodplains facies, forming probably at the lowermost portion of the alluvial fan depositional gradient, where it inter-fingers with basinal facies. In the Middle Bima Member, the facies architecture is dominantly suggestive of deep perennial sand-bed braided river system with thickly developed amalgamated trough crossbedded sandstone facies fining to mudstone. Couplets of shallow channels are also locally common, attesting to the varying topography of the basin. The Upper Bima Member is characterized by shallow perennial sand-bed braided river system composed of successive succession of planar and trough crossbedded sandstone facies associations, and shallower channels of the flashy ephemeral sheetflood sand - bed river systems defined by interbedded succession of small scale trough crossbedded sandstone facies and parallel laminated sandstone facies. The overall stacking pattern of the facies succession of the Bima Formation in the Gongola Sub - basin is generally thinning and fining upwards cycles, indicating scarp retreat and deposition in a relatively passive margin setting. Dominance of kaolinite in the clay mineral fraction of the Bima Formation points to predominance of humid sub - tropical to tropical climatic conditions. This favors pedogenic activities which are manifested in the several occurrences of paleosols. Pronounced periods of arid climatic conditions are also notable from the subordinate smectite mineralization. Chlorite mineralization at some localities is indicative of elevation of the provenance area, and this is synonymous with deposition of the Bima Formation, because of its syn - depositional tectonics. The absences of lacustrine shales in the syn - rift stratigraphic architecture of the Bima Formation indicates that the lower Cretaceous petroleum system that are common in the West and Central African Rift basins are generally barren in the Gongola Sub - basin of the Northern Benue Trough.

Tracking channel-floodplain sediment exchange with conservative and non-conservative geochemical tracers

NASA Astrophysics Data System (ADS)

Belmont, Patrick; Stout, Justin

2013-04-01

Fine sediment is routed through landscapes and channel networks in a highly unsteady and non-uniform manner, potentially experiencing deposition and re-suspension many times during transport from source to sink. Developing a better understanding of sediment routing at the landscape scale is an intriguing challenge from a modeling perspective because it requires consideration of a multitude of processes that interact and vary in space and time. From an applied perspective, an improved understanding of sediment routing is essential for predicting how conservation and restoration practices within a watershed will influence water quality, to support land and water management decisions. Two key uncertainties in predicting sediment routing at the landscape scale are 1) determining the proportion of suspended sediment that is derived from terrestrial (soil) erosion versus channel (bank) erosion, and 2) constraining the proportion of sediment that is temporarily stored and re-suspended within the channel-floodplain complex. Sediment fingerprinting that utilizes a suite of conservative and non-conservative geochemical tracers associated with suspended sediment can provide insight regarding both of these key uncertainties. Here we present a model that tracks suspended sediment with associated conservative and non-conservative geochemical tracers. The model assumes that particle residence times are described by a bimodal distribution wherein some fraction of sediment is transported through the system in a relatively short time (< 1 year) and the remainder experiences temporary storage (of variable duration) within the channel-floodplain complex. We use the model to explore the downstream evolution of non-conservative tracers under equilibrium conditions (i.e., exchange between the channel and floodplain is allowed, but no net change in channel-floodplain storage can occur) to illustrate how the process of channel-floodplain storage and re-suspension can potentially bias interpretation of sediment fingerprinting results. We then apply the model to explain measurements of meteoric Beryllium-10, Lead-210, and Cesium-137 associated with suspended sediment in two very different rivers, one incising (Le Sueur River, south-central Minnesota, USA) and the other aggrading (Root River, southeastern Minnesota, USA) in response to base level fall and rise, respectively. The Le Sueur River exhibits a remarkably narrow range of tracer concentrations in source areas, which include agricultural fields, alluvial banks, and bluffs. Suspended sediment samples collected immediately above and below the 30 km long incising reach show a systematic shift in terrestrial sources in the downstream direction, indicated by changes in Beryllium-10 concentrations. The Root River indicates a more variable erosion history, with significant variability of Beryllium-10 concentrations in source areas (agricultural fields, forested hillslopes, and alluvial floodplains and terraces) and inverted Beryllium-10 depth profiles (higher concentrations at depth, suggesting unsteady erosion and significant storage of legacy sediment). Both rivers show a systematic disparity in normalized concentrations of conservative versus non-conservative tracers, indicating that significant storage and re-suspension occurs in both systems as the sediment is routed through the channel-floodplain complex.

Influence of hydrologic modifications on Fraxinus pennsylvanica in the Mississippi River Alluvial Valley, USA

USGS Publications Warehouse

Gee, Hugo K.W.; King, Sammy L.; Keim, Richard F.

2015-01-01

We used tree-ring analysis to examine radial growth response of a common, moderately flood-tolerant species (Fraxinus pennsylvanica Marshall) to hydrologic and climatic variability for > 40 years before and after hydrologic modifications affecting two forest stands in the Mississippi River Alluvial Valley (USA): a stand without levees below dams and a stand within a ring levee. At the stand without levees below dams, spring flood stages decreased and overall growth increased after dam construction, which we attribute to a reduction in flood stress. At the stand within a ring levee, growth responded to the elimination of overbank flooding by shifting from being positively correlated with river stage to not being correlated with river stage. In general, growth in swales was positively correlated with river stage and Palmer Drought Severity Index (an index of soil moisture) for longer periods than flats. Growth decreased after levee construction, but swales were less impacted than flats likely because of differences in elevation and soils provide higher soil moisture. Results of this study indicate that broad-scale hydrologic processes differ in their effects on the flood regime, and the effects on growth of moderately flood-tolerant species such as F. pennsylvanica can be mediated by local-scale factors such as topographic position, which affects soil moisture.

Geomorphological Investigation of the Atchafalaya Basin, Area West, Atchafalaya Delta, and Terrebonne Marsh. Volume 1.

DTIC Science & Technology

1986-04-01

creating the recent alluvial valley and deltaic plain of southeastern Louisiana . Each time the Mississippi River has built a major delta lobe seaward...exposure during lowered sea level, relatively high bulk density , and low water content. Entrenchment of the ancestral Mississippi River into the...down to Houma, Louisiana . The exact time interval of Teche occupation by the Red River is not known, but it ended sometime between early and middle

Archeological and Palynological Analysis of Specimens and Materials Recovered in Two Historic Period Privies and a Well in Saint Alice Revetment, Saint James Parish, Louisiana.

DTIC Science & Technology

1982-01-01

Mississippi River in St. James Parish , Louisiana . This revetment lies on the right descending bank of the Mississippi River about 50 miles downstream from... river . It is not surprising, therefore, that the soils of the parish and the St. Alice Revetment study area within it are all, ultimately, alluvial in...History. In Cultural Resources Survey of Ten Project Areas on the Red River , Louisiana , by D. Bruck Dickson. New World Research Report of Investigations

The role of the Wetland Reserve Program in conservation efforts in the Mississippi River Alluvial Valley

USGS Publications Warehouse

King, Sammy L.; Twedt, Daniel J.; Wilson, R. Randy

2006-01-01

The Mississippi River Alluvial Valley includes the floodplain of the Mississippi River from Cairo, Illinois, USA, to the Gulf of Mexico. Originally this region supported about 10 million ha of bottomland hardwood forests, but only about 2.8 million ha remain today. Furthermore, most of the remaining bottomland forest is highly fragmented with altered hydrologic processes. During the 1990s landscape-scale conservation planning efforts were initiated for migratory birds and the threatened Louisiana black bear (Ursus americanus luteolus). These plans call for large-scale reforestation and restoration efforts in the region, particularly on private lands. In 1990 the Food, Agriculture, Conservation and Trade Act authorized the Wetlands Reserve Program (WRP). The WRP is a voluntary program administered by the United States Department of Agriculture that provides eligible landowners with financial incentives to restore wetlands and retire marginal farmlands from agricultural production. As of 30 September 2005, over 275,700 ha have been enrolled in the program in the Mississippi River Alluvial Valley, with the greatest concentration in Louisiana, Arkansas, and Mississippi, USA. Hydrologic restoration is common on most sites, with open-water wetlands, such as moist-soil units and sloughs, constituting up to 30% of a given tract. Over 33,200 ha of open-water wetlands have been created, potentially providing over 115,000,000 duck-use days. Twenty-three of 87 forest-bird conservation areas have met or exceed core habitat goals for migratory songbirds and another 24 have met minimum area requirements. The WRP played an integral role in the fulfillment of these goals. Although some landscape goals have been attained, the young age of the program and forest stands, and the lack of monitoring, has limited evaluations of the program's impact on wildlife populations.

Morphodynamic simulation of sediment deposition patterns on a recently stripped bedrock anastomosed channel

NASA Astrophysics Data System (ADS)

Milan, David; Heritage, George; Entwistle, Neil; Tooth, Stephen

2018-04-01

Some mixed bedrock-alluvial dryland rivers are known to undergo cycles of alluvial building during low flow periods, punctuated by stripping events during rare high magnitude flows. We focus on the Olifants River, Kruger National Park, South Africa, and present 2-D morphodynamic simulations of hydraulics and sediment deposition patterns over an exposed bedrock anastomosed pavement. We examine the assumptions underlying a previous conceptual model, namely that sedimentation occurs preferentially on bedrock highs. Our modelling results and local field observations in fact show that sediment thicknesses are greater over bedrock lows, suggesting these are the key loci for deposition, barform initiation and island building. During peak flows, velocities in the topographic lows tend to be lower than in intermediate topographic areas. It is likely that intermediate topographic areas supply sediment to the topographic lows at this flow stage, which is then deposited in the lows on the falling limb of the hydrograph as velocities reduce. Subsequent vegetation establishment on deposits in the topographic lows is likely to play a key role in additional sedimentation and vegetation succession, both through increasing the cohesive strength of alluvial units and by capturing new sediments and propagules.

Evaluating the impacts of crop rotations on groundwater storage and recharge in an agricultural watershed

Treesearch

Abdullah O. Dakhlalla; Prem B. Parajuli; Ying Ouyang; Darrel W. Schmitz

2016-01-01

The Mississippi River Valley Alluvial Aquifer, which underlies the Big Sunflower River Watershed (BSRW),is the most heavily used aquifer in Mississippi. Because the aquifer is primarily used for irrigating cropssuch as corn, cotton, soybean, and rice, the water levels have been declining rapidly over the past fewdecades. The objectives of this study are to...

Meander morphodynamics over self-formed floodplains: can the migration history affect the future morphology of the river?

NASA Astrophysics Data System (ADS)

Bogoni, M.; Lanzoni, S.; Putti, M.

2017-12-01

Floodplains, and rivers therein, constitute complex systems whose simulation involves modeling of hydrodynamic, morphodynamic, chemical, and biological processes which act over a wide range of time scales (from days to centuries) and affect each other. Self-formed floodplains are produced by the sedimentary processes associated with the migration of river bends and the formation of abandoned oxbow lakes consequent to the cutoff of mature meanders. The erosion and deposition processes at the banks lead to heterogeneities in the surface composition, thus the river may experience faster or slower migration rates depending on the spatial distribution of the erosional resistance. As a consequence, the past spatial configurations of the river (i.e. the migration history) play a key role in shaping the successive river paths.We recently published a paper addressing the modeling of meander morphodynamics over self-formed heterogeneous floodplain. Results show that the heterogeneity in floodplain composition associated with the formation of geomorphic units (i.e., scroll bars and oxbow lakes) and the choice of a reliable flow field model to drive channel migration are two fundamental ingredients for reproducing correctly the long-term morphodynamics of alluvial meanders. We compare numerically generated planforms obtained for different scenarios of floodplain heterogeneity to natural meandering paths, through half meander metrics and spatial distribution of channel curvatures. Statistical and spectral tools disclose the complexity embedded in meandering geometry and the crucial differences between apparently similar configurations.Floodplain heterogeneity affects both the temporal and spatial distributions of meander geometry, and eventually leads to a closer statistical similarity between simulated and natural planform shapes when scroll bars and oxbow lakes left behind are harder to erode than the surrounding floodplain.

Digital-model simulation of the Toppenish alluvial aquifer, Yakima Indian Reservation, Washington

USGS Publications Warehouse

Bolke, E.L.; Skrivan, James A.

1981-01-01

Increasing demands for irrigating additional lands and proposals to divert water from the Yakima River by water users downstream from the Yakima Indian Reservation have made an accounting of water availability important for present-day water management in the Toppenish Creek basin. A digital model was constructed and calibrated for the Toppenish alluvial aquifer to help fulfill this need. The average difference between observed and model-calculated aquifer heads was about 4 feet. Results of model analysis show that the net gain from the Yakima River to the aquifer is 90 cubic feet per second, and the net loss from the aquifer to Toppenish Creek is 137 cubic feet per second. Water-level declines of about 5 feet were calculated for an area near Toppenish in response to a hypothetical tenfold increase in 1974 pumping rates. (USGS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Dave; Miller, David; Kautsky, Mark

A uranium- and vanadium-ore-processing mill operated from 1954 to 1968 within the Navajo Nation near Shiprock, New Mexico. By September 1986, all tailings and structures on the former mill property were encapsulated in a disposal cell built on top of two existing tailings piles on the Shiprock site (the site) [1]. Local groundwater was contaminated by multiple inorganic constituents as a result of the milling operations. The U.S. Department of Energy (DOE) took over management of the site in 1978 as part of the Uranium Mill Tailings Remedial Action (UMTRA) Project. The DOE Office of Legacy Management currently manages ongoingmore » activities at the former mill facility, including groundwater remediation. Remediation activities are designed primarily to reduce the concentrations and total plume mass of the mill-related contaminants sulfate, uranium, and nitrate. In addition to contaminating groundwater in alluvial and bedrock sediments directly below the mill site, ore processing led to contamination of a nearby floodplain bordering the San Juan River. Groundwater in a shallow alluvial aquifer beneath the floodplain is strongly influenced by the morphology of the river channel as well as changing flows in the river, which provides drainage for regional runoff from the San Juan Mountains of Colorado. As part of a recent study of the floodplain hydrology, a revised conceptual model was developed for the alluvial aquifer along with an updated status of contaminant plumes that have been impacted by more than 10 years of groundwater pumping for site remediation purposes. Several findings from the recent study will be discussed here.« less

Diamonds from the Machado River alluvial deposit, Rondônia, Brazil, derived from both lithospheric and sublithospheric mantle

NASA Astrophysics Data System (ADS)

Burnham, A. D.; Bulanova, G. P.; Smith, C. B.; Whitehead, S. C.; Kohn, S. C.; Gobbo, L.; Walter, M. J.

2016-11-01

Diamonds from the Machado River alluvial deposit have been characterised on the basis of external morphology, internal textures, carbon isotopic composition, nitrogen concentration and aggregation state and mineral inclusion chemistry. Variations in morphology and features of abrasion suggest some diamonds have been derived directly from local kimberlites, whereas others have been through extensive sedimentary recycling. On the basis of mineral inclusion compositions, both lithospheric and sublithospheric diamonds are present at the deposit. The lithospheric diamonds have clear layer-by-layer octahedral and/or cuboid internal growth zonation, contain measurable nitrogen and indicate a heterogeneous lithospheric mantle beneath the region. The sublithospheric diamonds show a lack of regular sharp zonation, do not contain detectable nitrogen, are isotopically heavy (δ13CPDB predominantly - 0.7 to - 5.5) and contain inclusions of ferropericlase, former bridgmanite, majoritic garnet and former CaSiO3-perovskite. This suggests source lithologies that are Mg- and Ca-rich, probably including carbonates and serpentinites, subducted to lower mantle depths. The studied suite of sublithospheric diamonds has many similarities to the alluvial diamonds from Kankan, Guinea, but has more extreme variations in mineral inclusion chemistry. Of all superdeep diamond suites yet discovered, Machado River represents an end-member in terms of either the compositional range of materials being subducted to Transition Zone and lower mantle or the process by which materials are transferred from the subducted slab to the diamond-forming region.

Clay Mineralogy of AN Alluvial Aquifer in a Mountainous, Semiarid Terrain, AN Example from Rifle, Colorado

NASA Astrophysics Data System (ADS)

Elliott, W. C.; Lim, D.; Zaunbrecher, L. K.; Pickering, R. A.; Williams, K. H.; Navarre-Sitchler, A.; Long, P. E.; Noel, V.; Bargar, J.; Qafoku, N. P.

2015-12-01

Alluvial sediments deposited along the Colorado River corridor in the semi-arid regions of central to western Colorado can be important hosts for legacy contamination including U, V, As and Se. These alluvial sediments host aquifers which are thought to provide important "hot spots" and "hot moments" for microbiological activity controlling organic carbon processing and fluxes in the subsurface. Relatively little is known about the clay mineralogy of these alluvial aquifers and the parent alluvial sediments in spite of the fact that they commonly include lenses of silt-clay materials. These lenses are typically more reduced than coarser grained materials, but zones of reduced and more oxidized materials are present in these alluvial aquifer sediments. The clay mineralogy of the non-reduced parent alluvial sediments of the alluvial aquifer located in Rifle, CO (USA) is composed of chlorite, smectite, illite, kaolinite and quartz. The clay mineralogy of non-reduced fine-grained materials at Rifle are composed of the same suite of minerals found in the sediments plus a vermiculite-smectite intergrade that occurs near the bottom of the aquifer near the top of the Wasatch Formation. The clay mineral assemblages of the system reflect the mineralogically immature character of the source sediments. These assemblages are consistent with sediments and soils that formed in a moderately low rainfall climate and suggestive of minimal transport of the alluvial sediments from their source areas. Chlorite, smectite, smectite-vermiculite intergrade, and illite are the likely phases involved in the sorption of organic carbon and related microbial redox transformations of metals in these sediments. Both the occurrence and abundance of chlorite, smectite-vermiculite, illite and smectite can therefore exert an important control on the contaminant fluxes and are important determinants of biogeofacies in mountainous, semiarid terrains.

Determination of streamflow of the Arkansas River near Bentley in south-central Kansas

USGS Publications Warehouse

Perry, Charles A.

2012-01-01

The Kansas Department of Agriculture, Division of Water Resources, requires that the streamflow of the Arkansas River just upstream from Bentley in south-central Kansas be measured or calculated before groundwater can be pumped from the well field. When the daily streamflow of the Arkansas River near Bentley is less than 165 cubic feet per second (ft3/s), pumping must be curtailed. Daily streamflow near Bentley was calculated by determining the relations between streamflow data from two reference streamgages with a concurrent record of 24 years, one located 17.2 miles (mi) upstream and one located 10.9 mi downstream, and streamflow at a temporary gage located just upstream from Bentley (Arkansas River near Bentley, Kansas). Flow-duration curves for the two reference streamgages indicate that during 1988?2011, the mean daily streamflow was less than 165 ft3/s 30 to 35 percent of the time. During extreme low-flow (drought) conditions, the reach of the Arkansas River between Hutchinson and Maize can lose flow to the adjacent alluvial aquifer, with streamflow losses as much as 1.6 cubic feet per second per mile. Three models were developed to calculate the streamflow of the Arkansas River near Bentley, Kansas. The model chosen depends on the data available and on whether the reach of the Arkansas River between Hutchinson and Maize is gaining or losing groundwater from or to the adjacent alluvial aquifer. The first model was a pair of equations developed from linear regressions of the relation between daily streamflow data from the Bentley streamgage and daily streamflow data from either the Arkansas River near Hutchinson, Kansas, station (station number 07143330) or the Arkansas River near Maize, Kansas, station (station number 07143375). The standard error of the Hutchinson-only equation was 22.8 ft3/s, and the standard error of the Maize-only equation was 22.3 ft3/s. The single-station model would be used if only one streamgage was available. In the second model, the flow gradient between the streamflow near Hutchinson and the streamflow near Maize was used to calculate the streamflow at the Bentley streamgage. This equation resulted in a standard error of 26.7 ft3/s. In the third model, a multiple regression analysis between both the daily streamflow of the Arkansas River near Hutchinson, Kansas, and the daily streamflow of the Arkansas River near Maize, Kansas, was used to calculate the streamflow at the Bentley streamgage. The multiple regression equation had a standard error of 21.2 ft3/s, which was the smallest of the standard errors for all the models. An analysis of the number of low-flow days and the number of days when the reach between Hutchinson and Maize loses flow to the adjacent alluvial aquifer indicates that the long-term trend is toward fewer days of losing conditions. This trend may indicate a long-term increase in water levels in the alluvial aquifer, which could be caused by one or more of several conditions, including an increase in rainfall, a decrease in pumping, a decrease in temperature, and an increase in streamflow upstream from the Hutchinson-to-Maize reach of the Arkansas River.

Do rivers really obey power-laws? Using continuous high resolution measurements to define bankfull channel and evaluate downstream hydraulic-scaling over large changes in drainage area

NASA Astrophysics Data System (ADS)

Scher, C.; Tennant, C.; Larsen, L.; Bellugi, D. G.

2016-12-01

Advances in remote-sensing technology allow for cost-effective, accurate, high-resolution mapping of river-channel topography and shallow aquatic bathymetry over large spatial scales. A combination of near-infrared and green spectra airborne laser swath mapping was used to map river channel bathymetry and watershed geometry over 90+ river-kilometers (75-1175 km2) of the Greys River in Wyoming. The day of flight wetted channel was identified from green LiDAR returns, and more than 1800 valley-bottom cross-sections were extracted at regular 50-m intervals. The bankfull channel geometry was identified using a "watershed-based" algorithm that incrementally filled local minima to a "spill" point, thereby constraining areas of local convergence and delineating all the potential channels along the cross-section for each distinct "spill stage." Multiple potential channels in alluvial floodplains and lack of clearly defined channel banks in bedrock reaches challenge identification of the bankfull channel based on topology alone. Here we combine a variety of topological measures, geometrical considerations, and stage levels to define a stage-dependent bankfull channel geometry, and compare the results with day of flight wetted channel data. Initial results suggest that channel hydraulic geometry and basin hydrology power-law scaling may not accurately capture downstream channel adjustments for rivers draining complex mountain topography.

Identification and Large-Scale Mapping of Riverbed Facies along the Hanford Reach of the Columbia River for Hyporheic Zone Studies

NASA Astrophysics Data System (ADS)

Scheibe, T. D.; Hou, Z.; Murray, C. J.; Perkins, W. A.; Arntzen, E.; Richmond, M. C.; Mackley, R.; Johnson, T. C.

2016-12-01

The hyporheic zone (HZ) is the sediment layer underlying a river channel within which river water and groundwater may interact, and plays a significant role in controlling energy and nutrient fluxes and biogeochemical reactions in hydrologic systems. The area of this study is the HZ along the Hanford Reach of the Columbia River in southeastern Washington State, where daily and seasonal river stage changes, hydromorphology, and heterogeneous sediment texture drive groundwater-river water exchange and associated biogeochemical processes. The recent alluvial sediments immediately underlying the river are geologically distinct from the surrounding aquifer sediments, and serve as the primary locale of mixing and reaction. In order to effectively characterize the HZ, a novel approach was used to define and map recent alluvial (riverine) facies using river bathymetric attributes (e.g., slope, aspect, and local variability) and simulated hydrodynamic attributes (e.g., shear stress, flow velocity, river depth). The riverine facies were compared with riverbed substrate texture data for confirmation and quantification of textural relationships. Multiple flow regimes representing current (managed) and historical (unmanaged) flow hydrographs were considered to evaluate hydrodynamic controls on the current riverbed grain size distributions. Hydraulic properties were then mapped at reach and local scales by linking textural information to hydraulic property measurements from piezometers. The spatial distribution and thickness of riverine facies is being further constrained by integrating 3D time-lapse electrical resistivity tomography. The mapped distributions of riverine facies and the corresponding flow, transport and biogeochemical properties are supporting the parameterization of multiscale models of hyporheic exchange between groundwater and river water and associated biogeochemical transformations.

Distribution of Trichloroethylene and Geologic Controls on Contaminant Pathways near the Royal River, McKin Superfund Site Area, Gray, Maine

USGS Publications Warehouse

Lyford, Forest P.; Flight, L.E.; Stone, Janet Radway; Clifford, Scott

1999-01-01

Vapor-diffusion samplers were used in the autumn of 1997 to determine the lateral extent and distribution of concentrations of a trichloroethylene (TCE) plume in the ground-water discharge area near the McKin Superfund Site, Gray, Maine. Analyses of vapor in the samplers identified a plume about 800 feet wide entering the river near Boiling Springs, an area of ground-water discharge on the flood plain of the Royal River. The highest observed concentration of TCE in vapor was in an area of sand boils on the western bank of the river and about 200 feet downstream from Boiling Springs. Previous studies showed that most of the TCE load in the river originated in the area of the sand boils. In general, highest concentrations were observed on the western side of the river on the upgradient side of the plume, but TCE also was detected at numerous locations in the center and eastern bank of the river. The TCE plume discharges to the river where fine-grained glaciomarine sediments of the Presumpscot Formation are absent and where coarse-grained facies of buried glaciomarine fan deposits provide a pathway for ground-water flow. Based on results of analyses of vapor-diffusion samples and other previous studies, the plume appears to pass under and beyond the river near Boiling Springs and along the river for about 300 feet downstream from the sand boils. A coarse-grained, organic-rich layer at the base of the alluvial flood plain sediments is confined by overlying fine-grained alluvial sediments and may provide a conduit for ground-water leaking upward from buried glaciomarine fan deposits.

Fish assemblages in oxbow lakes relative to connectivity with the Mississippi River

USGS Publications Warehouse

Miranda, L.E.

2005-01-01

The alluvial valley of the lower Mississippi River contains hundreds of fluvial lakes that are periodically connected to the river during high water, although the frequency, duration, and timing of the connections vary. To help design plans to restore and preserve fish assemblages in these alluvial lakes, this investigation tested whether predictable patterns in lake fish assemblages were linked to the level of connectivity with the river. Results suggested that connectivity played an important role in structuring fish assemblages and that it was correlated with variables such as lake size, depth, distance from the river, and age, which exhibit a continuum of predictable features as the river migrates away from abandoned channels. Annual floods homogenize the floodplain and promote connectivity to various degrees, allowing for fish exchanges between river and floodplain that directly affect fish assemblages. The major physical changes linked to reduced connectivity are loss of depth and area, which in turn affect a multiplicity of abiotic and biotic features that indirectly affect community structure. In advanced stages of disconnection, fish assemblages in oxbow lakes are expected to include largely species that thrive in turbid, shallow systems with few predators and low oxygen content. When the river flowed without artificial restraint, oxbow lakes were created at the rate of 13-15 per century. At present, no or few oxbow lakes are being formed, and as existing lakes age, they are becoming shallower, smaller, and progressively more disconnected from the river. Given that modifications to the Mississippi River appear to be irreversible, conservation of this resource requires maintenance of existing lakes at a wide range of aging phases that provide diverse habitats and harbor distinct species assemblages.

Using geochemical tracers to distinguish groundwater and parafluvial inflows in rivers (the Avon Catchment, SE Australia)

NASA Astrophysics Data System (ADS)

Cartwright, I.; Hofmann, H.

2015-09-01

Understanding the location and magnitude of groundwater inflows to rivers is important for the protection of riverine ecosystems and the management of connected groundwater and surface water systems. Downstream trends in 222Rn activities and Cl concentrations in the Avon River, southeast Australia, implies that it contains alternating gaining and losing reaches. 222Rn activities of up to 3690 Bq m-3 imply that inflows are locally substantial (up to 3.1 m3 m-1 day-1). However, if it assumed that these inflows are solely from groundwater, the net groundwater inflows during low-flow periods exceed the measured increase in streamflow along the Avon River by up to 490 %. Uncertainties in the 222Rn activities of groundwater, the gas transfer coefficient, and the degree of hyporheic exchange cannot explain this discrepancy. It is proposed that a significant volume of the total calculated inflows into the Avon River represents water that exfiltrates from the river, flows through parafluvial sediments, and subsequently re-enters the river in the gaining reaches. This returning parafluvial flow has high 222Rn activities due to 222Rn emanations from the alluvial sediments. The riffle sections of the Avon River commonly have steep longitudinal gradients and may transition from losing at their upstream end to gaining at the downstream end and parafluvial flow through the sediment banks on meanders and point bars may also occur. Parafluvial flow is likely to be important in rivers with coarse-grained alluvial sediments on their floodplains and failure to quantify the input of 222Rn from parafluvial flow will result in overestimating groundwater inflows to rivers.

Field Demonstrations of Five Geophysical Methods that Could Be Used to Characterize Deposits of Alluvial Aggregate

USGS Publications Warehouse

Ellefsen, K.J.; Burton, B.L.; Lucius, J.E.; Haines, S.S.; Fitterman, D.V.; Witty, J.A.; Carlson, D.; Milburn, B.; Langer, W.H.

2007-01-01

Personnel from the U.S. Geological Survey and Martin Marietta Aggregates, Inc., conducted field demonstrations of five different geophysical methods to show how these methods could be used to characterize deposits of alluvial aggregate. The methods were time-domain electromagnetic sounding, electrical resistivity profiling, S-wave reflection profiling, S-wave refraction profiling, and P-wave refraction profiling. All demonstrations were conducted at one site within a river valley in central Indiana, where the stratigraphy consisted of 1 to 2 meters of clay-rich soil, 20 to 35 meters of alluvial sand and gravel, 1 to 6 meters of clay, and multiple layers of limestone and dolomite bedrock. All geophysical methods, except time-domain electromagnetic sounding, provided information about the alluvial aggregate that was consistent with the known geology. Although time-domain electromagnetic sounding did not work well at this site, it has worked well at other sites with different geology. All of these geophysical methods complement traditional methods of geologic characterization such as drilling.

Depositional setting and diagenetic evolution of some Tertiary unconventional reservoir rocks, Uinta Basin, Utah.

USGS Publications Warehouse

Pitman, Janet K.; Fouch, T.D.; Goldhaber, M.B.

1982-01-01

The Douglas Creek Member of the Tertiary Green River Formation underlies much of the Uinta basin, Utah, and contains large volumes of oil and gas trapped in a complex of fractured low-permeability sandstone reservoirs. In the SE part of the basin at Pariette Bench, the Eocene Douglas Creek Member is a thick sequence of fine- grained alluvial sandstone complexly intercalated with lacustrine claystone and carbonate rock. Sediments were deposited in a subsiding intermontane basin along the shallow fluctuating margin of ancient Lake Uinta. Although the Uinta basin has undergone postdepositional uplift and erosion, the deepest cored rocks at Pariette Bench have never been buried more than 3000m.-from Authors

Use of Ground-water Temperature Patterns to Determine the Hydraulic Conductance of the Streambed Along the Middle Reaches of the Russian River, CA

NASA Astrophysics Data System (ADS)

Su, G. W.; Constantz, J.; Jasperse, J.; Seymour, D.

2002-12-01

Along the Russian River in Sonoma County, the alluvial aquifer is the preferred source of drinking water because sediments and other constituents in the river water would require additional treatment. From late spring to early winter, an inflatable dam is erected to raise the river stage and passively recharge the alluvial aquifer. The raised stage also permits diversion of river water to a series of recharge ponds located near the dam along the river. Improved understanding of stream exchanges with ground water is needed to better manage available water resources. Heat is used as a tracer of shallow ground-water movement for detailed hydraulic parameter estimation along the middle reaches of the river. Water-levels and ground-water temperatures were measured in a series of observations wells and compared to the river stage and surface-water temperatures. Hydraulic conductivities were predicted by optimizing simulated ground-water temperatures using VS2DHI, a heat and water transport model, to observed temperatures in the aquifer. These conductivity values will be used in a stream/ground-water model of this region being developed using MODFLOW. Temperature-based estimates of streambed conductance will be inserted in the STREAM package of the model to constrain this parameter. Although temperature-based predictions of hydraulic conductivity vary significantly along the reach, the results generally suggest that an anisotropy of 5 to 1 (horizontal to vertical) provides the best hydraulic conductivity matches for predicted versus observed ground-water temperatures.

Late Quaternary landscape evolution in the Great Karoo, South Africa: Processes and drivers.

NASA Astrophysics Data System (ADS)

Oldknow, Chris; Hooke, Janet; Lang, Andreas

2016-04-01

The Great Karoo spans the north-central part of South Africa at a major climatic boundary. The characteristics, sequences, spatial patterns and drivers of river response to Late Quaternary climate changes in this region remain unclear due to the fragmentary alluvial/colluvial stratigraphic record and the lack of dated palaeoclimatic archives. Dendritic gully networks incised into deep deposits (up to 6 m) of colluvium and alluvium in the upper Sundays River catchment expose a legacy of "cut and fill" features. In 1st order tributaries, these are predominantly discontinuous palaeochannels and flood-outs with localised palaeosols, whereas in 2nd & 3rd order tributaries there are: 1) incised palaeo-geomorphic surfaces, 2) semi-continuous inset terrace sequences, 3) buried palaeo-gully topography. Using a combination of field mapping, logging of sediment outcrops, soil micromorphological and grain size analysis, mineral magnetic measurements and radiometric dating (OSL & 14C), we derive a stratigraphic evolution model which demonstrates a) the number of phases of incision, aggradation and pedogenesis, b) the spatial and temporal extent of each phase and c) the drivers of alluviation and associated feedbacks. Our reconstruction of regional valley alluviation indicates four distinct terrace units of contrasting depositional age. The base of the succession reflects slow aggradation under periglacial conditions associated with the Last Glacial Maximum. Subsequent channel entrenchment, causing terrace abandonment (T1) occurred in the deglacial period when vegetation and rainfall were in anti-phase. Re-instatement of connectivity with deep upland colluvial stores resulted in the injection of a pulse of sediment to valley floors, triggering compartmentalised backfilling (aggradation of T2) which propagated upstream as far as the second order drainage lines. This backfilling restructured the local hydrology, which, in concert with enhanced summer-rainfall, contributed to a major increase in the palaeo-water table, enhanced vegetation productivity and led to the formation of extensive calcified root-mats. Soil micromorphological evidence from this calcrete unit and burial of T2 by up to 1.5 m of alluvium (T3) indicates subsequent aridification, but depth of channel entrenchment was retarded by the blanketing effect of the underlying calcrete. The final terrace (T4) is much younger (Late Holocene), reflecting slow aggradation in a wetland setting. Wider segments of valley preserve a 'cut and fill' phase intermediate in age between regional T3 and T4 which appears to be a function of varying alluvial preservation potential. The research demonstrates that phases of alluviation and pedogenesis in these valleys reflect a complex interplay between Late Quaternary climate change and autogenic-feedbacks relating to abrupt changes in sediment supply and connectivity.

Publications - RI 97-14B | Alaska Division of Geological & Geophysical

Science.gov Websites

Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in , State of; Alluvial Deposits; Avalanche; Cambrian; Carboniferous; Cenozoic; Coastal and River; Coastal

Tracing Water Sources and Quantifying Evaporation in the Brazos River, Central Texas

NASA Astrophysics Data System (ADS)

VanPlantinga, A.; Hunt, L. E.; Winning, D.; Robertson, J.; Stockert, E.; Roark, E.; Grossman, E. L.

2013-12-01

Situated in the subtropical dry zone, Central Texas is sensitive to the effects of climate change, notably drought; furthermore, developments over the last century in agriculture, urban infrastructure, and river engineering have altered the landscape extensively. This study models water source mixing and seasonal variation in evaporation in Brazos River waters in Central Texas. The Brazos River from Waco to College Station, Texas is generally characterized as having dissolved salt load derived mostly from Lake Whitney (a flood-control and hydroelectric storage reservoir) and groundwater baseflow from the adjacent shallow alluvial aquifer. Brazos River water δ18O, δD, and conductivity were measured bi-weekly in Brazos County, Texas from January 2012 through August 2013. Conductivity, δ18O, and δD vary seasonally and are positively correlated. The Brazos River δ18O-δD data from Brazos County fall along a local evaporation line (δD = 5.66 * δ18O - 2.47, r2 = 0.95) that intersects and surpasses values for Lake Whitney. In contrast, the δ18O-conductivity trend for the Brazos River does not intersect data for Lake Whitney. These observations suggest mixing with an evaporated water source of lower conductivity. The relative contribution of other Brazos River water sources is uncertain. Percent evaporation of original rain sampled as Brazos River water was estimated using a Rayleigh distillation model and the method of Gonfiantini (1986) while assuming 1) a closed system with an atmospheric exchange component, and 2) δ18O and δD values of local rain are -5.33‰ and -32.6‰, respectively. Modeled percent evaporation of original rain varies from winter (JFM; 1%-20%) to spring (AMJ; 9-25%) to summer (JAS; 16-33%), to fall (OND; 15-24%). Rayleigh distillation modeling estimates are consistently higher (~5%) than those estimated by Gonfiantini's method. A simple mass-balance model predicts that Brazos River water percent evaporation and δ18O enrichment are 2.8% and 0.40‰ respectively for low flow in Brazos County (200 cubic feet per second or cfs) and 0.9% and 0.12‰ respectively for high flow (1000 cfs). This implies that a small percentage of evaporation of original rain in the Brazos River could be attributed to the alluvial aquifer. Thus, we believe that the alluvial aquifer is not dominating the Brazos River water supply as much as previously thought, even in times of low flow. Other surface waters more evaporatively enriched in 18O, specifically those derived from the network of local reservoirs and tributaries, likely influence the Brazos River more than previously thought.

Quantity and sources of base flow in the San Pedro River near Tombstone, Arizona

USGS Publications Warehouse

Kennedy, Jeffrey R.; Gungle, Bruce

2010-01-01

Base flow in the upper San Pedro River at the gaging station (USGS station 09471550) near Tombstone, Arizona, is an important factor in the long-term sustainability of the river's riparian ecosystem. Most base flow occurs during the non-summer months (typically, from November to May), because evapotranspiration (ET) is greater than groundwater discharge to the riparian zone during the growing season and typically causes periods of zero flow in the spring and fall. Streamflow during the summer months occurs only as a result of rainfall and runoff. Using a hydrograph separation technique that partitions streamflow into stormflow and base flow, based on the change in runoff from the previous day, median base flow at the Tombstone gage from 1968 to 2009 (1987 to 1996 data absent) is 4,890 acre-ft/yr. Median base flow for the earlier period of record, 1968 to 1986, is 5,830 acre-ft/yr and for the later period, 1997 to 2009, is 2,880 acre-ft/yr. Base flow in the upper San Pedro River is derived from groundwater discharge to the river from the regional and alluvial aquifer. The regional aquifer is defined as having recharge zones away from the river, primarily at mountain fronts and along ephemeral channels. The alluvial aquifer is recharged mainly from stormflow. Based on environmental isotope data, the composition of base flow in the upper San Pedro River at the gaging station near Tombstone is 74 +/- 10 percent regional groundwater and 26 +/- 10 percent summer storm runoff stored as alluvial groundwater for the 2000 to 2009 period. The volume of base flow in a given year is well explained, using multiple regression, by mean daily flow during the previous October and by rainfall during the months of December and January (R2 = 0.9). This does not suggest that streamflow is composed only of these two sources; rather, these two sources control the degree of saturation of the near-stream alluvial aquifer and, therefore, the amount of winter base-flow infiltration that is possible upstream of the Tombstone gaging station. Because of losing conditions upstream of the Tombstone gage, there is no minimum amount of base flow that would be expected in any given year. The regression equation was used to adjust the measured base flow to account for year-to-year variation in precipitation. Adjusted base flows decreased, independent of climate, from the early period of record to the late period of record. In addition to total base flow, other metrics were considered, including the start and end dates of base flow, the number of days of base flow, the 25th percentile mean daily flow, and the number of days of zero flow. Each of these showed a decline in base flow between the early period of record and the late period. The available evidence to evaluate this decrease - hydraulic gradients in the alluvial and regional aquifers and a 10-yr record of streamflow environmental isotope samples - indicates that no reduction in groundwater discharge has occurred over this period of record. Continued regional groundwater pumping will, however, eventually lead to a decline in the contribution of regional groundwater to base flow.

Antecedent rivers and early rifting: a case study from the Plio-Pleistocene Corinth rift, Greece

NASA Astrophysics Data System (ADS)

Hemelsdaël, Romain; Ford, Mary; Malartre, Fabrice

2016-04-01

Models of early rifting present syn-rift sedimentation as the direct response to the development of normal fault systems where footwall-derived drainage supplies alluvial to lacustrine sediments into hangingwall depocentres. These models often include antecedent rivers, diverted into active depocentres and with little impact on facies distributions. However, antecedent rivers can supply a high volume of sediment from the onset of rifting. What are the interactions between major antecedent rivers and a growing normal fault system? What are the implications for alluvial stratigraphy and facies distributions in early rifts? These questions are investigated by studying a Plio-Pleistocene fluvial succession on the southern margin of the Corinth rift (Greece). In the northern Peloponnese, early syn-rift deposits are preserved in a series of uplifted E-W normal fault blocks (10-15 km long, 3-7 km wide). Detailed sedimentary logging and high resolution mapping of the syn-rift succession (400 to 1300 m thick) define the architecture of the early rift alluvial system. Magnetostratigraphy and biostratigraphic markers are used to date and correlate the fluvial succession within and between fault blocks. The age of the succession is between 4.0 and 1.8 Ma. We present a new tectonostratigraphic model for early rift basins based on our reconstructions. The early rift depositional system was established across a series of narrow normal fault blocks. Palaeocurrent data show that the alluvial basin was supplied by one major sediment entry point. A low sinuosity braided river system flowed over 15 to 30 km to the NE. Facies evolved downstream from coarse conglomerates to fined-grained fluvial deposits. Other minor sediment entry points supply linked and isolated depocentres. The main river system terminated eastward where it built stacked small deltas into a shallow lake (5 to 15 m deep) that occupied the central Corinth rift. The main fluvial axis remained constant and controlled facies distribution throughout the early rift evolution. We show that the length scale of fluvial facies transitions is greater than and therefore not related to fault spacing. First order facies variations instead occur at the scale of the full antecedent fluvial system. Strike-parallel subsidence variations in individual fault blocks represent a second order controlling factor on stratigraphic architecture. As depocentres enlarged through time, sediments progressively filled palaeorelief, and formed a continuous alluvial plain above active faults. There was limited creation of footwall relief and thus no significant consequent drainage system developed. Here, instead of being diverted toward subsiding zones, the drainage system overfilled the whole rift from the onset of faulting. Moreover, the zones of maximum subsidence on individual faults are aligned across strike parallel to the persistent fluvial axis. This implies that long-term sediment loading influenced the growth of normal faults. We conclude that a major antecedent drainage system inherited from the Hellenide mountain belt supplied high volumes of coarse sediment from the onset of faulting in the western Corinth rift (around 4 Ma). These observations demonstrate that antecedent drainage systems can be important in the tectono-sedimentary evolution of rift basins.

Radiogenic 3He/4He Estimates and Their Effect on Calculating Plio-Pleistocene Cosmogenic 3He Ages of Alluvial-Fan Terraces in the Lower Colorado River Basin, USA

NASA Astrophysics Data System (ADS)

Fenton, C.; Pelletier, J.

2005-12-01

Several alluvial-fan terraces near Topock, AZ were created by successive entrenchment of Pliocene and Pleistocene alluvial-fan gravels shed from the adjacent Black Mountains along the lower Colorado River corridor below Hoover Dam. These fans interfinger with and overlie main-stem Colorado River sands and gravels and grade to terrace levels that correspond with pre-existing elevations of the Colorado River. Absolute dates for the ages of Quaternary deposits on the lower Colorado River are rare and cosmogenic 3He age estimates of these surfaces would help constrain the timing of aggradation and incision in the lower Colorado River corridor. We analyzed individual basalt boulders from several terrace surfaces for total 3He/4He concentrations to calculate cosmogenic 3He ages of each fan terrace; 3He/4He values, expressed as R/Ra where Ra is the 3He/4He of air, range from 0.29 to 590. Black Mountain volcanic rocks have reported K-Ar ages between 15 and 30 Ma and basalt samples from adjacent alluvial fans contain 0.42 to 47× 1012 at/g of 4He, which has likely accumulated due to nuclear processes. The amount of radiogenic 3He/4He can be significant in old rocks with young exposure ages and can complicate determination of cosmogenic 3 He content. Alpha-decay of U, Th, and their daughter isotopes produces large amounts of 4He, whereas significant amounts of radiogenic 3He are only produced through the neutron bombardment of Li and subsequent beta-decay of tritium. We measured Li, U, Th, major and rare-earth element concentrations in whole-rock basalts and mineral separates. These concentrations are used to estimate the ratio of radiogenic helium contributed to the total helium system in our samples. Li concentrations typically range from 6 to 17 ppm, with one outlier of 62 ppm. U contents range from <0.1 to 2.7 ppm and Th contents range from 0.4 to 15.3 ppm. Based on these values, our calculations predict that the average radiogenic helium (R/Ra) contributed to the total helium in Black Mountain basalt samples is 0.011. Other noble gas studies have shown that radiogenic 3He/4He is independent of the U content, nearly independent of the Th content, and strongly influenced by the Li content of a rock; we find the same results. It is assumed that mantle gases are released when the sample is crushed into a fine powder before melting in a furnace under vacuum. To correct for the possible presence of mantle gases in our age-calculations, we crushed two samples under vacuum to measure the R/Ra value (7.9 and 16.03) of mantle helium trapped in fluid inclusions in olivines and pyroxenes. Based on our 3He corrections and calculations, boulders on these alluvial fans range in age from 10 ka to 2.7 Ma.

Soil properties and growth of swamp white oak and pin oak on bedded soils in the lower Missouri River floodplain

Treesearch

John M. Kabrick; Daniel C. Dey; J. W. Van Sambeek; Michael Wallendorf; Michael A. Gold

2005-01-01

Restoring bottomland hardwood ecosystems is of great interest along the lower Missouri River and within the Mississippi Alluvial Valley. However, bottomland hardwood plantings commonly have a high failure rate. Among reasons cited for failures are frequent flooding and poorly drained site conditions. Soil bedding is a commonly used site preparation method shown to...

Discovering buried channels of the Yamuna in alluvial plains of NW India using geophysical investigations: implications for major drainage reorganization during Late Quaternary

NASA Astrophysics Data System (ADS)

Paul, D.; Khan, I.; Sinha, R.

2016-12-01

Climatic changes and active tectonic movements in the northwestern plains of India during the Late Quaternary have led to the migration and abandonment of drainage systems and formation of a large number of palaeochannels. It has been postulated by previous workers that the Yamuna was flowing along the present-day dry palaeochannels of Ghaggar-Hakra riverbed >120 Ka ago and was relocated to its current position only during the Late Quaternary. However, till date, no conclusive evidence has been provided as to when and why the Yamuna avulsion occurred. This study aims to establish sub-surface existence of buried channels of paleo-Yamuna as possible courses of the paleo-Ghaggar river. Geo-electric studies using vertical electrical resistivity soundings (1D-VES), multi electrode electrical resistivity tomography (2D-ERT) and multi probe well log surveys have been carried out in one of the paleochannels of the Yamuna to map the large-scale geometry and architecture of the palaeochannel system in the subsurface. The main objective is to reconstruct the shallow subsurface stratigraphy and alluvial architecture of the interfluve between the modern Yamuna and Sutlej Rivers, in particular the linkage of the paleocourses of the Yamuna River to the drainage network of the northwestern alluvial plains. The geophysical signatures recorded as VES on two transects trending NW-SE in Karnal and Kaithal districts of Haryana at 9 and 13 locations respectively along with continuous ERT reveals the presence of subsurface fine to coarse sand bodies (20 to 30m thick) interbedded with silty clay layers that are laterally stacked. The occurrence of thick and wide subsurface sand bodies in the subsurface implies that these are the deposits of a large river system and suggests that the Yamuna was connected to the paleo-Ghaggar River as hypothesized by earlier workers based on remote sensing techniques. However, detailed sedimentological and chronological constraints are required to establish such links to unravel the stratigraphic manifestation of the buried channels, their sediment provenance and paleoclimatic conditions during the period when these river systems were active.

Hydrologic scenarios for floodplain building in a vertically accreting, suspended sediment river

NASA Astrophysics Data System (ADS)

Alexander, J. S.; Scott, M. L.; Schmidt, J. C.

2006-12-01

Recent advances in dendrogeomorphology allow for precise age constraint on rates of floodplain building. We applied these techniques in our effort to evaluate the relative roles of flow regulation and invasive riparian vegetation in accelerating the rate of vertical accretion and channel narrowing of the dam-regulated upper Green River in Dinosaur National Monument, Colorado and Utah. Four large trenches were excavated into alluvial deposits that are now inundated by either common post-dam floods or rare post-dam high releases. We dated individual stratigraphic units using the recently developed stem-burial method (Friedman et al. 2005), as well as traditional cross-dating methods. These excavations indicate that episodic large floods with pre- dam recurrences of 5 to 10 years may vertically aggrade floodplains by up to 1.0 m. Smaller, more frequent, floods progressively create inset alluvial deposits that are subsequently colonized by native or non-native woody shrubs and trees. These lower elevation deposits serve as growing surfaces for both native and non- native riparian plants as well as stable platforms for deposition during occasional large post-dam floods that exceed the capacity of the dam's power plant. This style of floodplain building results in channel narrowing and loss of aquatic habitats. In the case of the upper Green River, the majority of channel narrowing occurred during two isolated events: (1) a rare basin-wide flood in late winter 1962, shortly before completion of Flaming Gorge Dam and (2) the largest post-dam bypass flood in 1983. Thick deposits of these ages occur in each trench, and this pattern correlates with the sequence of channel narrowing described by Allred and Schmidt (1999) 320 km downstream at the USGS gage near Green River, Utah. Our results suggest infrequent, controlled, high-magnitude dam releases may be an ineffective means of channel rejuvenation and vegetation control along vertically accreting, suspended sediment rivers. Where post-dam rivers are in a condition of sediment surplus, large floods may further isolate unwanted riparian vegetation from lower, more frequently disturbed hydrologic environments by increasing the elevation of the higher alluvial deposits.

Ground water in the Verdigris River basin, Kansas and Oklahoma

USGS Publications Warehouse

Fader, Stuart Wesley; Morton, Robert B.

1975-01-01

Ground water in the Verdigris River basin occurs in consolidated rocks and unconsolidated deposits ranging in age from Mississippian to Quaternary. Water for municipal, industrial, and irrigation supplies generally can be obtained in limited quantities from the alluvial deposits in the stream valleys. Except for water in the alluvial deposits in the stream valleys and in the outcrop areas of the bedrock aquifers, the groundwater is generally of poor chemical quality. Owing to the generally poor chemical quality of water and low yields to wells, an increase in the use of ground water from the consolidated rocks is improbable. The unconsolidated rocks in the Verdigris River basin receive about 166,000 acre-feet of recharge annually, and about 1 million acre-fee of water is in temporary storage in the deposits. In 1968 about 4,200 acre-feet of ground was withdrawn for all uses. About 800 acre-feet of ground and 5,000 acre-feet of surface water were pumped for irrigation of 5,300 acres of cropland. The total annual withdrawal of ground water for irrigation may be 2,000 acre-feet by the year 2000.

Source-to-sink sediment transfer in the Piave River system (North-Eastern Italy) since the Last Glacial Maximum

NASA Astrophysics Data System (ADS)

Carton, Alberto; Bondesan, Aldino; Fontana, Alessandro; Meneghel, Mirco; Miola, Antonella; Mozzi, Paolo; Primon, Sandra; Surian, Nicola

2010-05-01

Aim of this study is the definition of sediment production, transfer and deposition in the Piave River system from the Last Glacial Maximum to the Present, through a basin-scale approach. The Piave River flows from North to South in the eastern sector of the Italian Alps and reaches the Adriatic Sea. Its length is 220 km and the catchment is 3899 km2. The fluvial system consists of a mountainous portion, with maximum elevation of 3343 m a.s.l., and a lower part where the river flows in the Venetian alluvial plain. Average precipitation is 1350 mm/a; the runoff coefficient is 0.63 and the mean discharge at the mouth is 60 m3/s. The highest sediment delivery to the plain was at the peak of LGM, when the Piave glacier had its maximum expansion and reached the Alpine piedmont. In this period the Piave megafan received large volumes of sediments through glaciofluvial streams and achieved its maximum expansion. LGM alluvial sediments in the distal portion of the megafan are 20-30 m thick. The last glacial advance in the Vittorio Veneto terminal moraines, at the debouch of the valley in the Venetian Plain, dates 17.6 ka 14C BP. Deglaciation started immediately afterwards and the retreat of the glacial front was rather fast, considering that at around 15.0 ka 14C BP the Prealpine tract of valley was already ice-free. Following the onset of deglaciation until about 8.0 ka 14C BP, alluvial sediments were mostly trapped in the terminal valley tracts, while the whole alluvial plain experienced a severe erosive phase, comprising the whole Lateglacial and early Holocene. At ca. 8.0 ka 14C BP, the Piave River started to downcut its Prealpine valley fill, an event which re-mobilized the alluvial sediments and contributed to delta formation on the Adriatic coast since 6.0 ka 14C BP. Post-glacial aggradation in the distal tract of the Nervesa megafan started only at about 4.0 - 3.0 ka 14C BP. In Roman times the fluvial system was rather stable, while between the 5th and 10th century AD there were several major avulsions in the distal Nervesa megafan. The last 100 years are characterized by a dramatic decrease of sediment transport due to a range of human activities (e.g. sediment mining and dams). Climate change was the main external driving factor in this fluvial system at the LGM termination, controlling both sediment production in the catchment and sea-level position. Local factors, such as the occurrence of large landslides, lake formation, post-glacial reforestation and valley topography had a major impact on sediment transfer from source to sink. Holocene millennial- and centennial-scale climatic fluctuations were able to modulate the sediment flux, increasingly intermingling with human impact during the last 6 millennia.

Tracking groundwater discharge to a large river using tracers and geophysics.

PubMed

Harrington, Glenn A; Gardner, W Payton; Munday, Tim J

2014-01-01

Few studies have investigated large reaches of rivers in which multiple sources of groundwater are responsible for maintaining baseflow. This paper builds upon previous work undertaken along the Fitzroy River, one of the largest perennial river systems in north-western Australia. Synoptic regional-scale sampling of both river water and groundwater for a suite of environmental tracers ((4) He, (87) Sr/(86) Sr, (222) Rn and major ions), and subsequent modeling of tracer behavior in the river, has enabled definition and quantification of groundwater input from at least three different sources. We show unambiguous evidence of both shallow "local" groundwater, possibly recharged to alluvial aquifers beneath the adjacent floodplain during recent high-flow events, and old "regional" groundwater introduced via artesian flow from deep confined aquifers. We also invoke hyporheic exchange and either bank return flow or parafluvial flow to account for background (222) Rn activities and anomalous chloride trends along river reaches where there is no evidence of the local or regional groundwater inputs. Vertical conductivity sections acquired through an airborne electromagnetic (AEM) survey provide insights to the architecture of the aquifers associated with these sources and general groundwater quality characteristics. These data indicate fresh groundwater from about 300 m below ground preferentially discharging to the river, at locations consistent with those inferred from tracer data. The results demonstrate how sampling rivers for multiple environmental tracers of different types-including stable and radioactive isotopes, dissolved gases and major ions-can significantly improve conceptualization of groundwater-surface water interaction processes, particularly when coupled with geophysical techniques in complex hydrogeological settings. © 2013, National Ground Water Association.

Fluvial geomorphological response along the upland sediment cascade during the record-breaking December 2015 floods, Cumbria, UK

NASA Astrophysics Data System (ADS)

Russell, Andrew; Perks, Matthew; Large, Andrew; Dunning, Stuart; Warburton, Jeff

2016-04-01

Between 0900 GMT on 4th December and 0900 GMT on 6th December 2015, Atlantic Storm Desmond produced over 260 mm of rainfall in Cumbria, northwest England, representing a new UK 48 hour rainfall maximum, and breaking previous records set in 2005 and 2009. The December 2015 event resulted in a number of rivers significantly exceeding their 2009 levels, over-topping recently-commissioned flood defences, destroying bridges and flooding thousands of homes. Our research aim is to identify factors controlling significant geomorphological and sedimentary response during Storm Desmond along the upland sediment cascade including: Rattling Beck (Glenridding), a high gradient upland stream draining the flanks of Helvellyn (950 m.a.o.d.), and a 25km extended reach of the lower gradient piedmont Derwent River corridor downstream of Bassenthwaite Lake. Rattling Beck descends steeply from the eastern slopes of the Helvellyn massif draining across an alluvial fan into Lake Ullswater. On 5th December 2015 the village of Glenridding was severely impacted by flooding which deposited boulder-sized sediment within the centre of the village, completely blocking the pre-existing stream course and causing avulsion of waning stage flows through riverside properties. A major new sediment lobe was deposited on the existing alluvial fan downstream of the village, grading to the temporarily raised lake water level. Although a number of hillslope failures occurred in the higher catchment, the majority of the sediment transported by Rattling Beck and impacting the village was acquired within a 2km reach upstream of Glenridding through erosion of older glacial and alluvial sediments. Lateral channel erosion was enhanced by inability of flood flows to rework highly resistant boulder bar lag deposits related to a previous mine tailings dam failure in 1927. The River Derwent corridor extends for 30km downstream of Bassenthwaite Lake to the Irish Sea at Workington and has a sinuous course ranging in maximum width from 500m to <150m in reaches narrowed by human modification. Despite the Derwent's relatively low gradient, significant erosional and depositional impacts occurred as a result of Storm Desmond, often reactivating discrete areas along the river corridor that saw major sediment shift and channel alteration in the 2009 floods. 2015 channel avulsions are associated with floodplain erosion principally initiated by the ploughing of, and scour around, large woody debris. Large gravel sheets (< 0.5 km2) characterised by distal slip faces up to 1m high were deposited at river corridor expansions downstream of actively eroding hillslopes and artificially narrowed reaches. Overall, major geomorphological response to Storm Desmond floods in Rattling Beck and the River Derwent is seen to be amplified by centennial-scale human modifications to river corridors and alluvial fans. River corridor engineering on the River Derwent and village construction on Rattling Beck's depositional fan at Glenridding moved both systems out of their natural equilibrium exacerbating the effects of storm-generated flooding on the Derwent (2009, 2015) and Rattling Beck (2015).

The interaction of prehistoric human settlement, sea level change and tectonic uplift of the Coastal Range, eastern Taiwan

NASA Astrophysics Data System (ADS)

Yang, H.; Chen, W. S.

2017-12-01

The late Cenozoic mountain belt of Taiwan, resulting from the collision between the Eurasian and Philippine Sea plates, is known for its rapid tectonic uplift. As postglacial sea level rose ca. 15,000 yr ago, the eastern coast of Taiwan, due to the rapid tectonic uplift rate, displayed a totally different scenario comparing with most of the coastal plains around the world. At the beginning of postglacial era, the sea level rising rate was greater than the tectonic uplift rate which induced the original piedmont alluvial fan or coastal plain to be overwhelmed by sea water rapidly. Around 13.5 ka, the tectonic uplift rate caught up with the sea level rising and broad wave-cut platform formed. The approximation of tectonic uplift and sea level rising rates was lasting from 13.5 to 5ka, but shoreline progradation may have been enhanced by increased slope erosion which resulted in the alluvial fan forming at the later time of this period. As soon as the eustasy stabilized, the landmass continued to uplift which might have enhanced the river incising and wave erosion rapidly. Therefore the topographic expression along the eastern fringing of Coastal Range forms extended alluvial-fan, stream, and marine terraces and are covered by late Holocene colluvium and marine deposits. 88 archaeological sites were chosen in this study based on surface survey where the archaeological chronology of cultural stage is established primarily through examining pottery series and associated manual excavation. It is interesting that most of the archaeological sites were located on the alluvial fan although the Holocene marine terraces have formed after 5ka. There are no clear evidences to support a shore-oriented settlement, but the abundant alluvial depositional structures observed from the overlaying formation reveals the stream depositional system was still active at this time. If the Neolithic people wanted to come to the "new born" coastal region for the abundant ocean resources, they have to face the flat marine terraces should be still situated in inter-tidal or shallow sub-tidal zone and the alluvial fan where river began to incise might be a better choice for habitation.

Dependable water supplies from valley alluvium in arid regions.

PubMed

Van Haveren, Bruce P

2004-12-01

Reliable sources of high-quality water for domestic use are much needed in arid regions. Valley alluvium, coarse sand and gravel deposited by streams and rivers, provides an ideal storage medium for water in many regions of the world. However, river sediments will not accumulate in a valley without a natural or artificial barrier to slow the water. Sediments will deposit upstream of a barrier dam and form an alluvial deposit of relatively well-sorted material. The alluvium then acts as both an underground water-supply reservoir and a water filter, yielding a constant flow of high-quality water. Trap dams that store water in alluvial sediments and slowly release the filtered water represent an appropriate and inexpensive technology for combating desertification and mitigating the effects of drought at the community level. Small trap dams may be built as a community project using local materials and local labor.

Impacts of the Columbia River hydroelectric system on main-stem habitats of fall chinook salmon

USGS Publications Warehouse

Dauble, D.D.; Hanrahan, T.P.; Geist, D.R.; Parsley, M.J.

2003-01-01

Salmonid habitats in main-stem reaches of the Columbia and Snake rivers have changed dramatically during the past 60 years because of hydroelectric development and operation. Only about 13% and 58% of riverine habitats in the Columbia and Snake rivers, respectively, remain. Most riverine habitat is found in the upper Snake River; however, it is upstream of Hells Canyon Dam and not accessible to anadromous salmonids. We determined that approximately 661 and 805 km of the Columbia and Snake rivers, respectively, were once used by fall chinook salmon Oncorhynchus tshawytscha for spawning. Fall chinook salmon currently use only about 85 km of the main-stem Columbia River and 163 km of the main-stem Snake River for spawning. We used a geomorphic model to identify three river reaches downstream of present migration barriers with high potential for restoration of riverine processes: the Columbia River upstream of John Day Dam, the Columbia-Snake-Yakima River confluence, and the lower Snake River upstream of Little Goose Dam. Our analysis substantiated the assertion that historic spawning areas for fall chinook salmon occurred primarily within wide alluvial floodplains, which were once common in the mainstem Columbia and Snake rivers. These areas possessed more unconsolidated sediment and more bars and islands and had lower water surface slopes than did less extensively used areas. Because flows in the main stem are now highly regulated, the predevelopment alluvial river ecosystem is not expected to be restored simply by operational modification of one or more dams. Establishing more normative flow regimes - specifically, sustained peak flows for scouring - is essential to restoring the functional characteristics of existing, altered habitats. Restoring production of fall chinook salmon to any of these reaches also requires that population genetics and viability of potential seed populations (i.e., from tributaries, tailrace spawning areas, and hatcheries) be considered.

Morphodynamics: Rivers beyond steady state

NASA Astrophysics Data System (ADS)

Church, M.; Ferguson, R. I.

2015-04-01

The morphology of an alluvial river channel affects the movement of water and sediment along it, but in the longer run is shaped by those processes. This interplay has mostly been investigated empirically within the paradigm of Newtonian mechanics. In rivers, this has created an emphasis on equilibrium configurations with simple morphology and uniform steady flow. But transient adjustment, whether between equilibrium states or indefinitely, is to be expected in a world in which hydrology, sediment supply, and base level are not fixed. More fundamentally, water flows and all the phenomena that accompany them are inherently unsteady, and flows in natural channels are characteristically nonuniform. The morphodynamics of alluvial river channels is the striking consequence. In this paper, we develop the essential connection between the episodic nature of bed material transport and the production of river morphology, emphasizing the fundamental problems of sediment transport, the role of bar evolution in determining channel form, the role of riparian vegetation, and the wide range of time scales for change. As the key integrative exercise, we emphasize the importance of physics-based modeling of morphodynamics. We note consequences that can be of benefit to society if properly understood. These include the possibility to better be able to model how varying flows drive morphodynamic change, to understand the influence of the sediments themselves on morphodynamics, and to recognize the inherent necessity for rivers that transport bed material to deform laterally. We acknowledge pioneering contributions in WRR and elsewhere that have introduced some of these themes.

Geophysical techniques applied to urban planning in complex near surface environments. Examples of Zaragoza, NE Spain

NASA Astrophysics Data System (ADS)

Pueyo-Anchuela, Ó.; Casas-Sainz, A. M.; Soriano, M. A.; Pocoví-Juan, A.

Complex geological shallow subsurface environments represent an important handicap in urban and building projects. The geological features of the Central Ebro Basin, with sharp lateral changes in Quaternary deposits, alluvial karst phenomena and anthropic activity can preclude the characterization of future urban areas only from isolated geomechanical tests or from non-correctly dimensioned geophysical techniques. This complexity is here analyzed in two different test fields, (i) one of them linked to flat-bottomed valleys with irregular distribution of Quaternary deposits related to sharp lateral facies changes and irregular preconsolidated substratum position and (ii) a second one with similar complexities in the alluvial deposits and karst activity linked to solution of the underlying evaporite substratum. The results show that different geophysical techniques allow for similar geological models to be obtained in the first case (flat-bottomed valleys), whereas only the application of several geophysical techniques can permit to correctly evaluate the geological model complexities in the second case (alluvial karst). In this second case, the geological and superficial information permit to refine the sensitivity of the applied geophysical techniques to different indicators of karst activity. In both cases 3D models are needed to correctly distinguish alluvial lateral sedimentary changes from superimposed karstic activity.

The subfossil tree deposits from the Garonne Valley and their implications on Holocene alluvial plain dynamics

NASA Astrophysics Data System (ADS)

Carozza, Jean-Michel; Carozza, Laurent; Valette, Philippe; Llubes, Muriel; Py, Vanessa; Galop, Didier; Danu, Mihaela; Ferdinand, Laurie; David, Mélodie; Sévègnes, Laurent; Bruxelles, Laurent; Jarry, Marc; Duranthon, Francis

2014-01-01

Subfossil tree trunks deposits are common in large rivers, but their status as a source for dating alluvial sequences and palaeoenvironmental studies is still discussed. Particularly their origin and the process(es) of deposition as well as a possible remobilization were pointed as a limit to their use to document river alluvial changes. In this work we report the discovery of the largest subfossil trunks deposits in the Garonne valley. These new data are compared to the previous ones. A set of 17 tree trunks and more than 300 smaller wood fragments were collected. The xylologic study shows the prevalence of Quercus and a single occurrence of Ulmus. These two hardwood species are commonly associated with riparian forest. The 14C dating carried out on seven trunks and a single branch of Quercus on the outermost identified growth rings, indicates age ranging from 8400-8000 cal. BP for the oldest fragment (bough) to 4300-4000 cal. BP for the most recent tree trunk. Radiocarbon ages of the trunks are aggregated into two main periods: 5300-5600 cal. BP (four trunks) and 4300-4000 cal. BP (three trunks). The radiocarbon (charcoal) dating of the top of the alluvial sequence overlaying the trunks gives an age between 1965-1820 and 1570-1810 cal. BP, i.e. between the 2nd and the 5th c. AD. In addition, the discovery of two unpublished subfossil tree trunks deposits in Finhan are reported (six trunks). At the light of these results, we discuss previously proposed models for the Garonne floodplain building.

Developing a Composite Aquifer Vulnerability Assessment Model Combining DRASTIC with Agricultural Land Use in Choushui River Alluvial Fan, Central Taiwan

NASA Astrophysics Data System (ADS)

Chen, Shih-Kai; Hsieh, Chih-Heng; Tsai, Cheng-Bin

2017-04-01

Aquifer vulnerability assessment is considered to be an effective tool in controlling potential pollution which is critical for groundwater management. The Choushui River alluvial fan, located in central Taiwan, is an agricultural area with complex crop patterns and various irrigation schemes, which increased the difficulties in groundwater resource management. The aim of this study is to propose an integrated methodology to assess shallow groundwater vulnerability by including land-use impact on groundwater potential pollution. The original groundwater vulnerability methodology, DRASTIC, was modified by adding a land-use parameter in order to assess groundwater vulnerability under intense agricultural activities. To examine the prediction capacity of pollution for the modified DRASTIC model, various risk categories of contamination potentials were compared with observed nitrate-N obtained from groundwater monitoring network. It was found that for the original DRASTIC vulnerability map, some areas with low nitrate-N concentrations are covered within the high vulnerability areas, especially in the northern part of mid-fan areas, where rice paddy is the main crop and planted for two crop seasons per year. The low nitrate-N contamination potential of rice paddies may be resulted from the denitrification in the reduced root zone. By reducing the rating for rice paddies, the modified model was proved to be capable of increasing the precise of prediction in study area. The results can provide a basis for groundwater monitoring network design and effective preserve measures formulation in the mixed agricultural area. Keyword:Aquifer Vulnerability, Groundwater, DRASTIC, Nitrate-N

Ground-water flow and ground- and surface-water interaction at McBaine Bottoms, Columbia, Missouri--2000-02

USGS Publications Warehouse

Smith, Brenda J.

2003-01-01

McBaine Bottoms southwest of Columbia, Missouri, is the site of 4,269 acres of the Eagle Bluffs Conservation Area operated by the Missouri Department of Conservation, about 130 acres of the city of Columbia wastewater-treat-ment wetlands, and the city of Columbia munici-pal-supply well field. The city of Columbia wastewater-treatment wetlands supply treated effluent to the Eagle Bluffs Conservation Area. The presence of a sustained ground-water high underlying the Eagle Bluffs Conservation Area has indicated that ground-water flow is toward the municipal well field that supplies drinking water to the city of Columbia. The U.S. Geological Survey, in cooperation with the Missouri Department of Conservation and the city of Columbia, measured the ground-water levels in about 88 monitoring wells and the surface-water elevation at 4 sites monthly during a 27-month period to determine the ground-water flow and the ground- and surface-water interaction at McBaine Bottoms. Lateral ground-water flow was dominated by the presence of a ground-water high that was beneath the Eagle Bluffs Conservation Area and the presence of a cone of depression in the northern part of the study area. The ground-water high was present during all months of the study. Ground-water flow was radially away from the apex of the ground-water high; west and south of the high, flow was toward the Missouri River, east of the high, flow was toward Perche Creek, and north of the high, flow was toward the north toward the city of Columbia well field. The cone of depression was centered around the city of Columbia well field. Another permanent feature on the water-level maps was a ground-water high beneath treatment wetland unit 1. Although the ground-water high beneath the Eagle Bluffs Conservation Area was present throughout the study period, the configuration of the high changed depending on hydrologic conditions. Generally in the spring, the height of the ground-water high began to decrease and hydraulic gradients around the high became more shallow than in the winter months. In early summer, the high was the least pronounced. During mid-sum-mer, the high became more pronounced, and it continued to become higher, increasing until it reached its maximum height in late fall or early winter. Fluctuations in the ground-water high were partially produced by the cycle of flooding of the Eagle Bluffs Conservation Area wetland pools in the fall and subsequent drainage so crops could be planted in many of the wetland pools. The cone of depression in the northern part of the study area generally extended from the base of the ground-water high in the northern part of the Eagle Bluffs Conservation Area throughout the rest of the study area. The depth of the cone primarily was affected by the altitude of the Missouri River and the quantity of water being pumped from the alluvial aquifer by the city of Columbia well field. Ground-water flow in the alluvial aquifer in McBaine Bottoms in the late 1960?s before the development of the city of Columbia well field and the Eagle Bluffs Conservation Area was from northwest to southeast approximately parallel to the Missouri River. The ground-water high beneath the Eagle Bluffs Conservation Area and the cone of depression around the city of Columbia well field were not present in water-level maps for 1968 and 1978. The Missouri River can be a source of recharge to the alluvial aquifer. Generally the altitude of the river in the northern part of the study area was higher than the water table in the aquifer. Ground-water flow in this area was from the river into the alluvial aquifer. In the southern part of the study area adjacent to the Eagle Bluffs Conservation Area, the Missouri River was lower than the water table in the alluvial aquifer, indicating that the river was receiving water from the alluvial aquifer beneath the Eagle Bluffs Conservation Area.

Geomorphic response to tectonically-induced ground deformation in the Wabash Valley

USGS Publications Warehouse

Fraser, G.S.; Thompson, T.A.; Olyphant, G.A.; Furer, L.; Bennett, S.W.

1997-01-01

Numerous low- to moderate-intensity earthquakes have been recorded in a zone of diffuse modern seismicity in southwest Indiana, southeast Illinois, and northernmost Kentucky. Structural elements within the zone include the Wabash Valley Fault System, the LaSalle Anticlinal Belt in western Illinois, and the Rough Creek-Shawneetown Fault System in northern Kentucky. The presence of seismically-induced liquefaction features in the near-surface alluvial sediments in the region indicates that strong ground motion has occurred in the recent geological past, but because the glacial and alluvial sediments in the Wabash Valley appear to be otherwise undisturbed, post-Paleozoic ground deformation resulting from movement on these structural elements has not yet been documented. Morphometric analysis of the land surface, detailed mapping of geomorphic elements in the valley, reconnaissance drilling of the Holocene and Pleistocene alluvium, and structural analysis of the bedrock underlying the valley were used to determine whether the geomorphology of the valley and the patterns of alluviation of the Wabash River were affected by surface deformation associated with the seismic zone during the late Pleistocene and Holocene. Among the observed features in the valley that can be attributed to deformation are: (1) tilting of the modern land surface to the west, (2) preferred channel migration toward the west side of the valley, with concomitant impact on patterns of soil development and sedimentation rate, (3) a convex longitudinal profile of the Wabash River where it crosses the LaSalle Anticlinal Belt, and (4) increased incision of the river into its floodplain downstream from the anticlinal belt.

An Assessment of Regional Water Resources and Agricultural Sustainability in the Mississippi River Alluvial Aquifer System of Mississippi and Arkansas Under Current and Future Climate

NASA Astrophysics Data System (ADS)

Rigby, J.; Reba, M.

2011-12-01

The Lower Mississippi River Alluvial Plain is a highly productive agricultural region for rice, soy beans, and cotton that depends heavily on irrigation. Development of the Mississippi River Alluvial Aquifer (MRAA), one of the more prolific agricultural aquifers in the country, has traditionally been the primary source for irrigation in the region yielding over 1,100 Mgal/day to irrigation wells. Increasingly, the realities of changing climate and rapidly declining water tables have highlighted the necessity for new water management practices. Tail-water recovery and reuse is a rapidly expanding practice due in part to the efforts and cost-sharing of the NRCS, but regional studies of the potential for such practices to alleviate groundwater mining under current and future climate are lacking. While regional studies of aquifer geology have long been available, including assessments of regional groundwater flow, much about the aquifer is still not well understood including controls on recharge rates, a crucial component of water management design. We review the trends in regional availability of surface and groundwater resources, their current status, and the effects of recent changes in management practices on groundwater decline in Mississippi and Arkansas. Global and regional climate projections are used to assess scenarios of sustainable aquifer use under current land use and management along with the potential for more widely practiced surface water capture and reuse to alleviate groundwater decline. Finally, we highlight crucial knowledge gaps and challenges associated with the development of water management practices for sustainable agricultural use in the region.

Late Quaternary alluviation and offset along the eastern Big Pine fault, southern California

USGS Publications Warehouse

DeLong, S.B.; Minor, S.A.; Arnold, L.J.

2007-01-01

Determining late Quaternary offset rates on specific faults within active mountain belts is not only a key component of seismic hazard analysis, but sheds light on regional tectonic development over geologic timescales. Here we report an estimate of dip-slip rate on the eastern Big Pine oblique-reverse fault in the upper Cuyama Valley within the western Transverse Ranges of southern California, and its relation to local landscape development. Optically stimulated luminescence (OSL) dating of sandy beds within coarse-grained alluvial deposits indicates that deposition of alluvium shed from the Pine Mountain massif occurred near the southern margin of the Cuyama structural basin at the elevation of the Cuyama River between 25 and 14??ka. This alluvial deposit has been offset ??? 10??m vertically by the eastern Big Pine fault, providing a latest Quaternary dip-slip rate estimate of ??? 0.9??m/ky based on a 50?? fault dip. Incision of the adjacent Cuyama River has exposed a section of older Cuyama River sediments beneath the Pine Mountain alluvium that accumulated between 45 and 30??ka on the down-thrown footwall block of the eastern Big Pine fault. Corroborative evidence for Holocene reverse-slip on the eastern Big Pine fault is ??? 1??m of incised bedrock that is characteristically exposed beneath 2-3.5??ka fill terraces in tributaries south of the fault. The eastern Big Pine fault in the Cuyama Valley area has no confirmed record of historic rupture; however, based on our results, we suggest the likelihood of multiple reverse-slip rupture events since 14??ka. ?? 2007 Elsevier B.V. All rights reserved.

Soft-sediment deformation structures in the late Miocene Şelmo Formation around Adıyaman area, Southeastern Turkey

NASA Astrophysics Data System (ADS)

Koç Taşgın, Calibe; Orhan, Hükmü; Türkmen, İbrahim; Aksoy, Ercan

2011-04-01

The Şelmo Formation was deposited in the basins associated with the Southeastern Anatolian Thrust Belt and East Anatolian Fault Zone in SE Turkey. These structures developed as a result of compressional stresses created by the movement of the Arabian plate to the north and the Eurasian plate to the west from early Miocene to late Pliocene. The outcrops of the Şelmo Formation in the Adýyaman area (SE Turkey) comprise braided river deposits (lower alluvial unit) at the base, lacustrine and deltaic deposits in the middle (lacustrine unit) and low sinuousity river and alluvial deposits at the top (upper alluvial unit). Soft-sediment deformation structures were developed in sandstone, siltstone and marl of the deltaic and lacustrine unit of the Şelmo Formation. These are slumps, recumbent folds, load casts, ball-and-pillow structures, flame structures, neptunian dykes, chaotically associated structures and synsedimentary faults. The tectonic setting of the basin, the lateral extent of the soft-sediment deformation structures over tens of kilometers, their similarities to deformation structures interpreted as being induced seismically in other regions worldwide or in a laboratory setting, and being confined by undeformed layers suggest that the main trigger system was related to seismic activity in the area.

Laboratory alluvial fans in one dimension.

PubMed

Guerit, L; Métivier, F; Devauchelle, O; Lajeunesse, E; Barrier, L

2014-08-01

When they reach a flat plain, rivers often deposit their sediment load into a cone-shaped structure called alluvial fan. We present a simplified experimental setup that reproduces, in one dimension, basic features of alluvial fans. A mixture of water and glycerol transports and deposits glass beads between two transparent panels separated by a narrow gap. As the beads, which mimic natural sediments, get deposited in this gap, they form an almost one-dimensional fan. At a moderate sediment discharge, the fan grows quasistatically and maintains its slope just above the threshold for sediment transport. The water discharge determines this critical slope. At leading order, the sediment discharge only controls the velocity at which the fan grows. A more detailed analysis reveals a slight curvature of the fan profile, which relates directly to the rate at which sediments are transported.

Length scale hierarchy and spatiotemporal change of alluvial morphologies over the Selenga River delta, Russia

NASA Astrophysics Data System (ADS)

Dong, T. Y.; Nittrouer, J.; McElroy, B. J.; Ma, H.; Czapiga, M. J.; Il'icheva, E.; Pavlov, M.; Parker, G.

2017-12-01

The movement of water and sediment in natural channels creates various types of alluvial morphologies that span length scales from dunes to deltas. The behavior of these morphologies is controlled microscopically by hydrodynamic conditions and bed material size, and macroscopically by hydrologic and geological settings. Alluvial morphologies can be modeled as either diffusive or kinematic waves, in accordance with their respective boundary conditions. Recently, it has been shown that the difference between these two dynamic behaviors of alluvial morphologies can be characterized by the backwater number, which is a dimensionless value normalizing the length scale of a morphological feature to its local hydrodynamic condition. Application of the backwater number has proven useful for evaluating the size of morphologies, including deltas (e.g., by assessing the preferential avulsion location of a lobe), and for comparing bedform types across different fluvial systems. Yet two critical questions emerge when applying the backwater number: First, how do different types of alluvial morphologies compare within a single deltaic system, where there is a hydrodynamic transition from uniform to non-uniform flow? Second, how do different types of morphologies evolve temporally within a system as a function of changing water discharge? This study addresses these questions by compiling and analyzing field data from the Selenga River delta, Russia, which include measurements of flow velocity, channel geometry, bed material grain size, and channel slope, as well as length scales of various morphologies, including dunes, island bars, meanders, bifurcations, and delta lobes. Data analyses reveal that the length scale of morphologies decrease and the backwater number increases as flow transitions from uniform to non-uniform conditions progressing downstream. It is shown that the evaluated length scale hierarchy and planform distribution of different morphologies can be used to estimate slope, shear velocity and sediment flux within this depositional system. The findings from this research can be applied to evaluate spatially and temporally varying morphodynamic conditions, based on structures measured from both modern systems and ancient sedimentary records.

Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma

USGS Publications Warehouse

Adams, G.P.; Runkle, D.L.; Rea, Alan

1997-01-01

ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of of hydraulic conductivity, recharge, and ground-water level elevation contours for the alluvial and terrace deposits along the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma. Ground water in 830 square miles of the Quaternary-age alluvial and terrace aquifer is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. The aquifer consists of poorly sorted, fine to coarse, unconsolidated quartz sand with minor amounts of clay, silt, and basal gravel. The hydraulically connected alluvial and terrace deposits unconformably overlie the Tertiary-age Ogallala Formation and Permian-age formations. Most of the lines in the aquifer boundary and recharge data sets and some of the lines in the hydraulic conductivity data set were extracted from a published digital surficial geology data set based on a scale of 1:250,000. The ground-water elevation contours and some of the lines for the aquifer boundary, hydraulic conductivity, and recharge data sets were digitized from a ground-water modeling report about the aquifer published at a scale of 1:250,000. The hydraulic conductivity values and recharge rates also are from the ground-water modeling report. The data sets are provided in both nonproprietary and ARC/INFO export file formats. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

Regional groundwater-flow model of the Redwall-Muav, Coconino, and alluvial basin aquifer systems of northern and central Arizona

USGS Publications Warehouse

Pool, D.R.; Blasch, Kyle W.; Callegary, James B.; Leake, Stanley A.; Graser, Leslie F.

2011-01-01

A numerical flow model (MODFLOW) of the groundwater flow system in the primary aquifers in northern Arizona was developed to simulate interactions between the aquifers, perennial streams, and springs for predevelopment and transient conditions during 1910 through 2005. Simulated aquifers include the Redwall-Muav, Coconino, and basin-fill aquifers. Perennial stream reaches and springs that derive base flow from the aquifers were simulated, including the Colorado River, Little Colorado River, Salt River, Verde River, and perennial reaches of tributary streams. Simulated major springs include Blue Spring, Del Rio Springs, Havasu Springs, Verde River headwater springs, several springs that discharge adjacent to major Verde River tributaries, and many springs that discharge to the Colorado River. Estimates of aquifer hydraulic properties and groundwater budgets were developed from published reports and groundwater-flow models. Spatial extents of aquifers and confining units were developed from geologic data, geophysical models, a groundwater-flow model for the Prescott Active Management Area, drill logs, geologic logs, and geophysical logs. Spatial and temporal distributions of natural recharge were developed by using a water-balance model that estimates recharge from direct infiltration. Additional natural recharge from ephemeral channel infiltration was simulated in alluvial basins. Recharge at wastewater treatment facilities and incidental recharge at agricultural fields and golf courses were also simulated. Estimates of predevelopment rates of groundwater discharge to streams, springs, and evapotranspiration by phreatophytes were derived from previous reports and on the basis of streamflow records at gages. Annual estimates of groundwater withdrawals for agriculture, municipal, industrial, and domestic uses were developed from several sources, including reported withdrawals for nonexempt wells, estimated crop requirements for agricultural wells, and estimated per capita water use for exempt wells. Accuracy of the simulated groundwater-flow system was evaluated by using observational control from water levels in wells, estimates of base flow from streamflow records, and estimates of spring discharge. Major results from the simulations include the importance of variations in recharge rates throughout the study area and recharge along ephemeral and losing stream reaches in alluvial basins. Insights about the groundwater-flow systems in individual basins include the hydrologic influence of geologic structures in some areas and that stream-aquifer interactions along the lower part of the Little Colorado River are an effective control on water level distributions throughout the Little Colorado River Plateau basin. Better information on several aspects of the groundwater flow system are needed to reduce uncertainty of the simulated system. Many areas lack documentation of the response of the groundwater system to changes in withdrawals and recharge. Data needed to define groundwater flow between vertically adjacent water-bearing units is lacking in many areas. Distributions of recharge along losing stream reaches are poorly defined. Extents of aquifers and alluvial lithologies are poorly defined in parts of the Big Chino and Verde Valley sub-basins. Aquifer storage properties are poorly defined throughout most of the study area. Little data exist to define the hydrologic importance of geologic structures such as faults and fractures. Discharge of regional groundwater flow to the Verde River is difficult to identify in the Verde Valley sub-basin because of unknown contributions from deep percolation of excess surface water irrigation.

The Miocene Roof Mapping Using Microtremor Recording and Electrical Survey Method in Blida City, Algeria

NASA Astrophysics Data System (ADS)

Bouchelouh, Assia; Bensalem, Rabah; Zaourar, Naima; Machane, Djamel; Moulouel, Hakim; Oubaiche, El Hadi

2018-01-01

Bedrock depths in the Mitidja basin in general and in the Blida region in particular are still poorly known despite, the existence of some relatively deep hydraulic boreholes that intersect only superficial alluvial formations. To assess the seismic risk of Blida town, knowledge of soil amplification requires the thickness and properties of sedimentary formations that cover the substratum. For the purposes of our study, the thicknesses obtained by the vertical electric soundings, carried out in the hydrogeological study of the basin, were combined with horizontal-to-vertical spectral ratio (HVSR) microtremor recordings. This combination made it possible to determine an empirical relationship between frequency and thickness specific to the Blida site area, which enabled the roof of the Miocene to be mapped and shows slight undulations with directions compatible with the tectonic constraints of the region. The boundaries between the low and high frequencies obtained by HVSR are well materialized, at south by Sidi El Kebir river, at west by Chiffa river and in the central part by a line of direction SE-NW corresponding to the old passage of Sidi El Kebir river. The presence of low frequencies attributed to the old alluvial deposits with significant thicknesses that originate just after Sidi El Kebir river confirms that the South Mitidjian contact is subvertical.

Occurrence, Distribution, Sources, and Trends of Elevated Chloride Concentrations in the Mississippi River Valley Alluvial Aquifer in Southeastern Arkansas

USGS Publications Warehouse

Kresse, Timothy M.; Clark, Brian R.

2008-01-01

Water-quality data from approximately 2,500 sites were used to investigate the distribution of chloride concentrations in the Mississippi River Valley alluvial aquifer in southeastern Arkansas. The large volume and areal distribution of the data used for the investigation proved useful in delineating areas of elevated (greater than 100 milligrams per liter) chloride concentrations, assessing potential sources of saline water, and evaluating trends in chloride distribution and concentration over time. Irrigation water containing elevated chloride concentrations is associated with negative effects to rice and soybeans, two of the major crops in Arkansas, and a groundwater chloride concentration of 100 milligrams per liter is recommended as the upper limit for use on rice. As such, accurately delineating areas with high salinity ground water, defining potential sources of chloride, and documenting trends over time is important in assisting the agricultural community in water management. The distribution and range of chloride concentrations in the study area revealed distinct areas of elevated chloride concentrations. Area I includes an elongated, generally northwest-southeast trending band of moderately elevated chloride concentrations in the northern part of the study area. This band of elevated chloride concentrations is approximately 40 miles in length and varies from approximately 2 to 9 miles in width, with a maximum chloride concentration of 360 milligrams per liter. Area II is a narrow, north-south trending band of elevated chloride concentrations in the southern part of the study area, with a maximum chloride concentration of 1,639 milligrams per liter. A zone of chloride concentrations exceeding 200 milligrams per liter is approximately 25 miles in length and 5 to 6 miles in width. In Area I, low chloride concentrations in samples from wells completed in the alluvial aquifer next to the Arkansas River and in samples from the upper Claiborne aquifer, which underlies the alluvial aquifer, indicate that leakage from the river and upward flow of saline water in underlying aquifers are not likely sources for the saline water in the alluvial aquifer in Area I. A good comparison was noted for chloride concentrations in Area I and surface geomorphology. In the majority of cases, elevated chloride concentrations occurred in backswamp deposits, with low concentrations (less than 50 milligrams per liter) in areas of active or abandoned channel deposits. The fine-grained, clay-rich deposits associated with backswamp areas likely restrict recharge, induce increased ratios between evapotranspiration and recharge, and experience minimal flushing of salts concentrated during evapotranspiration. In Area II, chloride isoconcentration maps of the underlying upper Claiborne aquifer, in addition to samples from wells completed in the middle and lower Claiborne aquifers, showed a similar chloride distribution to that of the alluvial aquifer with decreasing chloride concentrations to the east of the zone of elevated chloride concentrations, which suggests a deeper source of saline water that affects Tertiary and Quaternary aquifer systems. Mixing curves developed from bromide/chloride ratios in water samples from the alluvial aquifer, Tertiary aquifers, and samples of brine water from the Jurrasic Smackover Formation additionally discounted upward flow of saline water from underlying Tertiary formations as a potential mechanism for salinity in the alluvial aquifer in Area II. A review of information on oil exploration wells in Chicot County revealed that most of these wells were drilled from 1960 to 1980, after the elevated chloride concentrations were detected in the early 1950s. The elongated nature of the zone of elevated chloride concentrations in Area II suggests a line source or linear conduit connection with the source. Maps of a fractured limestone in the Smackover Formation in Arkansas, Mississippi, and Louisiana for purpose

Geomorphology of the lower Copper River, Alaska

USGS Publications Warehouse

Brabets, T.P.

1996-01-01

The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1996, 11 bridges were located along this section of the highway. These bridges cross parts or all of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. At the peak outflow rate from Van Cleve Lake, the flow of the Copper River will increase an additional 140,000 and 190,000 cubic feet per second. Bedload sampling and continuous seismic reflection were used to show that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lakes, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow- gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake, long-term flow characteristics of the lower Copper River were synthesized. Historical discharge and cross-section data indicate that as late as 1970, most of the flow of the lower Copper River was through the first three bridges of the Copper River Highway as it begins to traverse the alluvial flood plain. In the mid 1980's, a percentage of the flow had shifted away from these three bridges and in 1995, only 51 percent of the flow of the Copper River passed through them. Eight different years of aerial photography of the lower Copper River were analyzed using Geographical Information System techniques. This analysis indicated that no major channel changes were caused by the 1964 earthquake. A flood in 1981 that had a recurrence interval of more than 100 years caused significant channel changes in the lower Copper River. A probability analysis of the lower Copper River indicated stable areas and the long-term locations of channels. By knowing the number of times a particular area has been occupied by water and the last year an area was occupied by water, areas of instability can be located. A Markov analysis of the lower Copper River indicated that the tendency of the flood plain is to remain in its current state. Large floods of the magnitude of the 1981 event are believed to be the cause of major changes in the lower Copper River.

Geomorphology of the lower Copper River, Alaska

USGS Publications Warehouse

Brabets, Timothy P.

1997-01-01

The Copper River, located in southcentral Alaska, drains an area of more than 24,000 square miles. About 30 miles above its mouth, this large river enters Miles Lake, a proglacial lake formed by the retreat of Miles Glacier. Downstream from the outlet of Miles Lake, the Copper River flows past the face of Childs Glacier before it enters a large, broad, alluvial flood plain. The Copper River Highway traverses this flood plain and in 1995, 11 bridges were located along this section of the highway. These bridges cross parts of the Copper River and in recent years, some of these bridges have sustained serious damage due to the changing course of the Copper River. Although the annual mean discharge of the lower Copper River is 57,400 cubic feet per second, most of the flow occurs during the summer months from snowmelt, rainfall, and glacial melt. Approximately every six years, an outburst flood from Van Cleve Lake, a glacier-dammed lake formed by Miles Glacier, releases approximately 1 million acre-feet of water into the Copper River. When the outflow rate from Van Cleve Lake reaches it peak, the flow of the Copper River will increase between 150,000 to 190,000 cubic feet per second. Data collected by bedload sampling and continuous seismic reflection indicated that Miles Lake traps virtually all the bedload being transported by the Copper River as it enters the lake from the north. The reservoir-like effect of Miles Lake results in the armoring of the channel of the Copper River downstream from Miles Lake, past Childs Glacier, until it reaches the alluvial flood plain. At this point, bedload transport begins again. The lower Copper River transports 69 million tons per year of suspended sediment, approximately the same quantity as the Yukon River, which drains an area of more than 300,000 square miles. By correlating concurrent flows from a long-term streamflow-gaging station on the Copper River with a short-term streamflow-gaging station at the outlet of Miles Lake, long-term flow characteristics of the lower Copper River were synthesized. Historical discharge and cross-section data indicate that as late as 1970, most of the flow of the lower Copper River was through the first three bridges of the Copper River Highway as it begins to traverse the alluvial flood plain. In the mid 1980's, a percentage of the flow had shifted away from these three bridges and in 1995, only 51 percent of the flow of the Copper River passed through them. Eight different years of aerial photography of the lower Copper River were analyzed using Geographical Information System techniques. This analysis indicated that no major channel changes were caused by the 1964 earthquake. However, a flood in 1981 that had a recurrence interval of more than 100 years caused significant channel changes in the lower Copper River. A probability analysis of the lower Copper River indicated stable areas and the long-term locations of channels. By knowing the number of times a particular area has been occupied by water and the last year an area was occupied by water, areas of instability can be located. A Markov analysis of the lower Copper River indicated that the tendency of the flood plain is to remain in its current state. Large floods of the magnitude of the 1981 event are believed to be the cause of major changes in the lower Copper River.

Denitrification and mixing in a stream-aquifer system: Effects on nitrate loading to surface water

USGS Publications Warehouse

McMahon, P.B.; Böhlke, J.K.

1996-01-01

Ground water in terrace deposits of the South Platte River alluvial aquifer near Greeley, Colorado, USA, had a median nitrate concentration of 1857 ??mol l-1. Median nitrate concentrations in ground water from adjacent floodplain deposits (468 ??mol l-1) and riverbed sediments (461 ??mol l-1), both of which are downgradient from the terrace deposits, were lower than the median concentration in the terrace deposits. The concentrations and ??15N values of nitrate and N2 in ground water indicated that denitrifying activity in the floodplain deposits and riverbed sediments accounted for 15- 30% of the difference in nitrate concentrations. Concentrations of Cl- and SiO2 indicated that mixing between river water and ground water in the floodplain deposits and riverbed sediments accounted for the remainder of the difference in nitrate concentrations. River flux measurements indicated that ground-water discharge in a 7.5 km segment of river had a nitrate load of 1718 kg N day-1 and accounted for about 18% of the total nitrate load in the river at the downstream end of that segment. This nitrate load was 70% less than the load predicted on the basis of the median nitrate concentration in the terrace deposits and assuming no denitrification or mixing in the aquifer. Water exchange between the river and aquifer caused ground water that originally discharged to the river to reenter denitrifying sediments in the riverbed and floodplain, thereby further decreasing the nitrate load in this stream-aquifer system. Results from this study indicated that denitrification and mixing within alluvial aquifer sediments may substantially decrease the nitrate load added to rivers by discharging ground water.

Distribution and variability of redox zones controlling spatial variability of arsenic in the Mississippi River Valley alluvial aquifer, southeastern Arkansas

USGS Publications Warehouse

Sharif, M.U.; Davis, R.K.; Steele, K.F.; Kim, B.; Hays, P.D.; Kresse, T.M.; Fazio, J.A.

2008-01-01

Twenty one of 118 irrigation water wells in the shallow (25-30??m thick) Mississippi River Valley alluvial aquifer in the Bayou Bartholomew watershed, southeastern Arkansas had arsenic (As) concentrations (< 0.5 to 77????g/L) exceeding 10????g/L. Sediment and groundwater samples were collected and analyzed from the sites of the highest, median, and lowest concentrations of As in groundwater in the alluvial aquifers located at Jefferson County, Arkansas. A traditional five-step sequential extraction was performed to differentiate the exchangeable, carbonate, amorphous Fe and Mn oxide, organic, and hot HNO3-leachable fraction of As and other compounds in sediments. The Chao reagent (0.25??M hydroxylamine hydrochloride in 0.25??M HCl) removes amorphous Fe and Mn oxides and oxyhydroxides (present as coatings on grains and amorphous minerals) by reductive dissolution and is a measure of reducible Fe and Mn in sediments. The hot HNO3 extraction removes mostly crystalline metal oxides and all other labile forms of As. Significant total As (20%) is complexed with amorphous Fe and Mn oxides in sediments. Arsenic abundance is not significant in carbonates or organic matter. Significant (40-70????g/kg) exchangeable As is only present at shallow depth (0-1??m below ground surface). Arsenic is positively correlated to Fe extracted by Chao reagent (r = 0.83) and hot HNO3 (r = 0.85). Arsenic extracted by Chao reagent decreases significantly with depth as compared to As extracted by hot HNO3. Fe (II)/Fe (the ratio of Fe concentration in the extracts of Chao reagent and hot HNO3) is positively correlated (r = 0.76) to As extracted from Chao reagent. Although Fe (II)/Fe increases with depth, the relative abundance of reducible Fe decreases noticeably with depth. The amount of reducible Fe, as well as As complexed to amorphous Fe and Mn oxides and oxyhydroxides decreases with depth. Possible explanations for the decrease in reducible Fe and its complexed As with depth include historic flushing of As and Fe from hydrous ferric oxides (HFO) by microbially-mediated reductive dissolution and aging of HFO to crystalline phases. Hydrogeochemical data suggests that the groundwater in the area falls in the mildly reducing (suboxic) to relatively highly reducing (anoxic) zone, and points to reductive dissolution of HFO as the dominant As release mechanism. Spatial variability of gypsum solubility and simultaneous SO42- reduction with co-precipitation of As and sulfide is an important limiting process controlling the concentration of As in groundwater in the area. ?? 2008 Elsevier B.V. All rights reserved.

Comparative geomorphic analysis of surficial deposits at three central Appalachian watersheds: Implications for controls on sediment-transport efficiency

NASA Astrophysics Data System (ADS)

Taylor, Stephen B.; Steven Kite, J.

2006-08-01

Factors that control the routing and storage of sediments in the Appalachian region are poorly understood. This study involves a comparative geomorphic analysis of three watersheds underlain by sandstones and shales of the Acadian clastic wedge. These areas include the Fernow Experimental Forest, Tucker County, West Virginia; the North Fork basin, Pocahontas County, West Virginia; and the Little River basin, Augusta County, Virginia. GIS-based analyses of surficial map units allow first-order approximation of sediment-storage volumes in valley bottoms. Estimates of volumes are examined in tandem with morphometric analyses and the distribution of bedrock channels to make inferences regarding controls on sediment-transport efficiency in the central Appalachians. The Fernow and North Fork areas are characterized by V-shaped valleys with mixed reaches of alluvial-bedrock channels distributed throughout the drainage network. In contrast, the Little River valley is notably wider and gravelly alluvial fill is abundant. Comparator watershed parameters for the Fernow, North Fork and Little River areas include, respectively: (1) basin area = 15.2 km 2, 49.3 km 2, 41.5 km 2; (2) basin relief = 0.586 km, 0.533 km, 0.828 km; (3) drainage density = 4.2 km - 1 , 3.3 km - 1 , 4.7 km - 1 ; (4) ruggedness = 2.5, 1.7, 3.9; (5) Shreve magnitude = 139, 287, 380; (6) total valley-bottom area (km 2) = 0.76 km 2, 1.86 km 2, 3.09 km 2; (7) average hillslope gradients = 17.2°, 18.4°, 22.1°; (8) total debris-fan surface area = 0.113 km 2, 0.165 km 2, 0.486 km 2; and (9) debris-fan frequency = 2.0 km - 2 , 1.0 km - 2 , 2.8 km - 2 . The storage volumes in valley bottoms were estimated using map polygon areas and surface heights above channel grade. The Little River contains significantly higher sediment volumes in floodplain, terrace and fan storage compartments; total volumes of the valley bottoms are approximately twice that of the Fernow and North Fork areas combined. Unit storage volumes for the Fernow, North Fork and Little River are 5.2 × 10 4 m 3 km - 2 , 5.5 × 10 4 m 3 km - 2 and 1.6 × 10 5 m 3 km - 2 , respectively. A conceptual model postulates that valley-width morphometry and style of delivery from hillslopes are the primary factors controlling the efficiency of sediment transport. Steep, debris-flow-prone hillslopes at the Little River deliver high volumes of gravelly sediment at magnitudes greater than transport capacity of the channel. Patterns of stream power are complex, as low-order tributaries are under capacity and high-order tributaries over capacity with respect to sediment load. Aggraded alluvial fill insulates valley-floor bedrock from vertical erosion and valley widening dominates. Expansion of the valley width creates a positive response via increased storage capacity and lower unit stream power. Conversely, the Fernow and North Fork are characterized by diffusive mass movement on hillslopes with incremental bedload transport to higher-order tributaries. Rates of hillslope delivery are balanced by the rate of channel export. Mixed alluvial-bedrock reaches provide the optimal channel configuration for active incision of the valley floor. Low expansion of valley width promotes high unit stream power and processes of vertical erosion. The model implies that the Fernow and North Fork have been more effective at sediment transport during the Late Quaternary. Given similar climatic and tectonic settings, variation in bedrock lithofacies is likely the primary factor modulating the efficiency of sediment transport.

The Changing Geomorphic Template of Native Fish Habitat of the Lower San Rafael River, Utah

NASA Astrophysics Data System (ADS)

Fortney, S. T.; Dean, D. J.; Schmidt, J. C.

2010-12-01

The physical template of the aquatic ecosystem of the lower San Rafael River (UT) changed dramatically during the 20th century. 1938 aerial photographs depict a channel comprised of multiple threads with numerous bars. The river has since been transformed into a single-thread channel with a low width-to-depth ratio. The drastic changes in the channel geometry have resulted in severely degraded habitat conditions. Despite these changes in habitat quality and quantity, roundtail chub, flannelmouth sucker, and bluehead sucker are still found in isolated patches of complex habitat. Three factors are primarily responsible for changes in the channel geomorphology: (1) reduced magnitude and duration of the spring snowmelt flood, (2) dense establishment of tamarisk (Tamarix spp) throughout the alluvial valley, and (3) continued supply of fine sediment from ephemeral tributaries. We determined the degree and rate of geomorphic change by analyzing spatially-rich data extracted from aerial photographs and temporally-rich data recorded at USGS gage 09328500. We evaluated channel morphologic processes by interpreting stratigraphy in floodplain trenches and dated these alluvial deposits using dendro-geomorphic techniques. We correlated the flood record to floodplain deposits, thus determining the role of floods in shaping the present channel. Aerial photography analysis shows that a 10-km reach cumulatively narrowed 62% during a span of 44 years. Between 1949 and 1970, the channel cross-section at USGS gage 09328500 narrowed by 60% and incised its bed approximately 1.2 m. Rating relations since the 1980’s provide corroborative evidence that channel narrowing and reduction in channel capacity continues; today, parts of the channel bed are on bedrock, thereby preventing further incision. Stratigraphy observed in a 40-m long trench demonstrates that the channel has narrowed by oblique and vertical accretion processes. Dendrogeomorphic results elucidate the relative role of channel forming mechanisms; and the combination of spatially extensive and temporally rich analyses reveals that feedback mechanisms facilitate in channel adjustment. These results will guide efforts to restore fish habitat and rehabilitate the San Rafael River by tamarisk eradication, in-stream flow augmentation, and reconnection of channel and floodplain habitats.

Altitude of the water table in the alluvial and other shallow aquifers along the Colorado River near La Grange, Texas, December 1980

USGS Publications Warehouse

Rettman, Paul

1981-01-01

The delineation of the water table in the alluvium of the Colorado River is fairly well defined, and 10-feet contour intervals may be interpreted with confidence in the area called ' potential lignite-mining area. ' The water table in the bedrock aquifers is more difficult to delineate with the available data; therefore, the contours are only estimates of the position of the water table in the hilly bedrock area adjacent to the Colorado River alluvium. 

Mississippi River delta as seen from the Gemini 9-A spacecraft

NASA Technical Reports Server (NTRS)

1966-01-01

The Mississippi River delta, and Gulf coasts of Louisiana, Mississippi, Alabama and Florida as seen from the Gemini 9-A spacecraft during its first revolution of the earth. Florida peninsula is seen at upper right corner of picture. lake Pontchartrain is at lower left. new orleans is located between the lake and the U-shaped bend in the river. Large bay at top left center is Mobile Bay. Apalachicola, Florida, is the point of land at top center of picture. Note alluvial deposit at mouths of Mississippi.

An Integration of Ground-Penetrating Radar, Remote Sensing, and Discharge Records of the Modern Kicking Horse River, BC

NASA Astrophysics Data System (ADS)

Cyples, N.; Ielpi, A.; Dirszowsky, R.

2017-12-01

The Kicking Horse River is a gravel-bed stream originating from glacial meltwater supplied by the Wapta Icefields in south-eastern British Columbia. An alluvial tract extends for 7 km through Field, BC, where the trunk channel undergoes diurnal and seasonal fluctuations in flow as a result of varying glacial-meltwater supply and runoff recharge. Prior studies erected the Kicking Horse River as a reference for proximal braided systems, and documented bar formation and sediment distribution patterns from ground observations. However, a consistent model of planform evolution and related stratigraphic signature is lacking. Specific objectives of this study are to examine the morphodynamic evolution and stratigraphic signature of channel-bar complexes using high-resolution satellite imagery, sedimentologic and discharge observations, and ground-penetrating radar (GPR). Remote sensing highlights rates of lateral channel migration of as much as 270 meters over eight years ( 34 meters/year), and demonstrates how flood stages are associated with stepwise episodes of channel braiding and anabranching. GPR analysis aided in the identification of five distinct radar facies, including: discontinuous, inclined, planar, trough-shaped, and mounded reflectors, which were respectively related to specific architectural elements and fluvial processes responsible for bar evolution. Across-stream GPR transects demonstrated higher heterogeneity in facies distribution, while downstream-oriented transects yielded a more monotonous distribution in radar facies. Notably, large-scale inclined reflectors related to step-wise bar accretion are depicted only in downstream-oriented transects, while discontinuous reflectors related to bedform stacking appear to be dominant in along-stream transects. Integration of sedimentological data with remote sensing, gauging records, and GPR analysis allows for high-resolution modelling of stepwise changes in alluvial morphology. Conceptual models stemming from such analyses can be employed to understand the depositional history and stratigraphic signature of proximal and coarse-grained fluvial systems.

Hydrogeology and quality of ground water in the upper Arkansas River basin from Buena Vista to Salida, Colorado, 2000-2003

USGS Publications Warehouse

Watts, Kenneth R.

2005-01-01

The upper Arkansas River Basin between Buena Vista and Salida, Colorado, is a downfaulted basin, the Buena Vista-Salida structural basin, located between the Sawatch and Mosquito Ranges. The primary aquifers in the Buena Vista-Salida structural basin consist of poorly consolidated to unconsolidated Quaternary-age alluvial and glacial deposits and Tertiary-age basin-fill deposits. Maximum thickness of the alluvial, glacial, and basin-fill deposits is about 5,000 feet, but 95 percent of the water-supply wells in Chaffee County are no more than 300 feet deep. Hydrologic conditions in the 149-square mile study area are described on the basis of hydrologic and geologic data compiled and collected during September 2000 through September 2003. The principal aquifers described in this report are the alluvial-outwash and basin-fill aquifers. An estimated 3,443 wells pumped about 690 to 1,240 acre-feet for domestic and household use in Chaffee County during 2003. By 2030, projected increases in the population of Chaffee County, Colorado, may require use of an additional 4,000 to 5,000 wells to supply an additional 800 to 1,800 acre-feet per year of ground water for domestic and household supply. The estimated specific yield of the upper 300 feet of the alluvial-outwash and basin-fill aquifers ranged from about 0.02 to 0.2. Current (2003) and projected (2030) ground-water withdrawals by domestic and household wells are less than 1 percent of the estimated 472,000 acre-feet of drainable ground water in the upper 300 feet of the subsurface. Locally, little water is available in the upper 300 feet. In densely populated areas, well interference could result in decreased water levels and well yields, which may require deepening or replacement of wells. Infiltration of surface water diverted for irrigation and from losing streams is the primary source of ground-water recharge in the semiarid basin. Ground-water levels in the alluvial-outwash and basin-fill aquifers vary seasonally with maximum water levels occurring in the early summer after snowmelt runoff peaks. Because of the drought during 2002, relatively large declines in ground-water levels occurred in about one-half of the monitored wells. Differences in water-level altitudes in shallow and deep wells indicate the potential for downward flow in upland areas and support results of preliminary cross-sectional models of ground-water flow. The apparent mean age of ground-water recharge ranged from about 1 to more than 48 years before 2001. The older (pre-1953) water was from wells that were located in ground-water discharge areas. Ground-water flow in the Buena Vista-Salida structural basin drains eastward toward the Arkansas River and, locally, toward the South Arkansas River. Ground water in the alluvial-outwash and basin-fill aquifers generally is calcium-bicarbonate water type with less than 250 milligrams per liter dissolved solids. Nitrate concentrations generally were less than 1 to 2 milligrams per liter and do not indicate widespread contamination of ground water from surface sources.

Geologic map of the East of Grotto Hills Quadrangle, California: a digital database

USGS Publications Warehouse

Nielson, Jane E.; Bedford, David R.

1999-01-01

The East of Grotto Hills 1:24,000-scale quadrangle of California lies west of the Colorado River about 30 km southwest of Searchlight, Nevada, near the boundary between the northern and southern parts of the Basin and Range Province. The quadrangle includes the eastern margin of Lanfair Valley, the southernmost part of the Castle Mountains, and part of the northwest Piute Range. The generally north-trending Piute Range aligns with the Piute and Dead Mountains of California and the Newberry and Eldorado Mountains and McCullough Range of Nevada. The southern part of the Piute Range adjoins Homer Mountain (Spencer and Turner, 1985) near Civil War-era Fort Piute. Adjacent 1:24,000-scale quadrangles include Castle Peaks, Homer Mountain, and Signal Hill, Calif.; also Hart Peak, Tenmile Well, and West of Juniper Mine, Calif. and Nev. The mapped area contains Tertiary (Miocene) volcanic and sedimentary rocks, interbedded with and overlain by Tertiary and Quaternary surficial deposits. Miocene intrusions mark conduits that served as feeders for the Miocene volcanic rocks, which also contain late magma pulses that cut the volcanic section. Upper Miocene conglomerate deposits interfinger with the uppermost volcanic flows. Canyons and intermontane valleys contain dissected Quaternary alluvial-fan deposits, mantled by active alluvial-fan deposits and detritus of active drainages. The alluvial materials were derived largely from Early Proterozoic granite and gneiss complexes, intruded by Mesozoic granite, dominate the heads of Lanfair Valley drainages in the New York Mountains and Mid Hills (fig. 1; Jennings, 1961). Similar rocks also underlie Tertiary deposits in the Castle Peaks, Castle Mountains, and eastern Piute Range.

Uncertainties in simulating river/groundwater exchanges over the Upper Rhine Graben hydrosystem

NASA Astrophysics Data System (ADS)

Vergnes, Jean-Pierre; Habets, Florence

2014-05-01

The Upper Rhine alluvial aquifer is an important transboundary water resource which is particularly vulnerable to pollution from the rivers due to anthropogenic activities. A realistic simulation of the groundwater-river exchanges is therefore of crucial importance for an effective management of water resources. Characterization of these fluxes in term of quantity and spatio-temporal variability depends on choices made to represent the river water stage in the model as well as on the hydrogeological parameters. Recently, a coupled surface-subsurface model has been applied to the whole aquifer basin (Thierion et al., 2012). The present study aims at improving the estimation of the river/groundwater exchange, and thus, of the hydrodynamic of the alluvial aquifer, and at getting an idea of the associated uncertainty by performing a set of simulations that best take advantage of the different kinds of observed data. The general modeling strategy is based on the Eau-Dyssée modeling platform which couples existing specialized models to address water resources quantity and quality in small to regional scale river basins. In this study, Eau-Dyssée includes the ISBA surface scheme that estimates the water balance, the RAPID river routing model and the SAM hydrogeological model. In addition, the QtoZ module (Saleh et al., 2011) is used to calculate the river stage from simulated river discharges, which is then used to calculate the exchanges between aquifer units and river, according to three different approaches that are compared: a control experiment with constant river water stage, a rating curves approach derived from observed river discharges and river stages, and the Manning's formula, for which Manning's parameters are defined according to geomorphological parameterizations and topographic data based on Digital Elevation Model (DEM). Supplementary sensitivity tests are also performed by using different hydrogeological parameter datasets (porosity and transmissivity). Two sources of DEM were used for this part. Additionally, sensitivity to the time step of the estimation (daily versus monthly) was studied. The evaluation is made against observed water levels and river discharges collected both from the french and german riversides of the alluvial plain. A heavy network of water table depth observations is also available to evaluate the simulated piezometric heads. Preliminary results show that the primary source of errors when simulating river stage - and hence groundwater-river interactions - is the uncertainties associated with the topographic data used to define the riverbed elevation. It confirms the need to access to more accurate DEM for estimating riverbed elevation and studying groundwater-river interactions, at least at regional scale. References Saleh, F., Flipo, N., Habets, F., Ducharne, A., Oudin, L., Viennot, P., Ledoux, E. Modeling the impact of in-stream water level fluctuations on stream-aquifer interactions at the regional scale (2011)Journal of Hydrology, 400 (3-4) pp 490-500 Thierion C., Longuevergne L., Habets F. Ledoux E., Ackerer P., Majdalani S., Leblois E., Lecluse S., Martin E, Queguiner S., Viennot P., Assessing the water balance of the Upper Rhine Graben hydrosystem, Journal of Hydrology 424-425 , pp. 68-83

Bed load tracer mobility in a mixed bedrock/alluvial channel

NASA Astrophysics Data System (ADS)

Ferguson, R. I.; Sharma, B. P.; Hodge, R. A.; Hardy, R. J.; Warburton, J.

2017-04-01

The presence of bare or partially covered rock in an otherwise alluvial river implies a downstream change in transport capacity relative to supply. Field investigations of this change and what causes it are lacking. We used two sets of magnet-tagged tracer clasts to investigate bed load transport during the same sequence of floods in fully alluvial, bare rock, and partial-cover reaches of an upland stream. High-flow shear stresses in different reaches were calculated by using stage loggers. Tracers seeded in the upstream alluvial channel moved more slowly than elsewhere until the frontrunners reached bare rock and sped up. Tracers seeded on bare rock moved rapidly off it and accumulated just upstream from, and later in, a partial-cover zone with many boulders. The backwater effect of the boulder-rich zone is significant in reducing tracer mobility. Tracer movement over full or partial sediment cover was size selective but dispersion over bare rock was not. Along-channel changes in tracer mobility are interpreted in terms of measured differences in shear stress and estimated differences in threshold stress.

Accelerated loading evaluation of subbase layers in pavement performance : tech summary.

DOT National Transportation Integrated Search

2009-04-01

The mighty Mississippi River formed and sculpted most of south Louisiana, creating large areas of alluvial : deposits consisting of soft, wet, and unconsolidated soil layers. Many Louisiana pavements were built in : these areas of naturally low shear...

U-Th-Ra variations in Himalayan river sediments (Gandak river, India): Weathering fractionation and/or grain-size sorting?

NASA Astrophysics Data System (ADS)

Bosia, Clio; Chabaux, François; Pelt, Eric; France-Lanord, Christian; Morin, Guillaume; Lavé, Jérôme; Stille, Peter

2016-11-01

Understanding the origin of U-Th-Ra variations in the Ganga river sediments is a prerequisite for correctly using U-series nuclides to constrain the sediment transport times in Himalayan rivers. For this purpose, U, Th, and Ra concentrations, along with 238U-234U-230Th-226Ra radioactive disequilibria, were analyzed in bank, bedload and suspended sediments from the Gandak river, one of the main tributaries of the Ganga river. The data confirm that U and Th budgets of the Himalayan sediments are significantly influenced by minor resistant minerals, such as zircon, garnet and Ti-bearing minerals, the dissolution of which required the use of a high-pressure acid digestion process. Most importantly, the results indicate that the variations in (238U/232Th) and (230Th/232Th) activity ratios and 238U-234U-230Th-226Ra disequilibria in sediments along the river alluvial plain mainly reflect modifications in the mineralogical and grain-size compositions rather than the degree of weathering during transport. The (238U/232Th) and (230Th/232Th) activity ratios in the bank and bed sediments are related to variations in the minor primary minerals strongly enriched in U and Th (i.e., zircon, REE-bearing minerals and Ti-bearing minerals), whereas the activity ratios in the suspended load are related to variations in the proportions of clay, Fe-oxyhydroxides and the silt-sand fraction, which contains U- and Th-bearing minor minerals. The data also indicate that 238U-234U-230Th-226Ra disequilibria are strongly influenced by secondary mineral phases: the 230Th budget is likely mainly controlled by Fe-oxyhydroxides, and the 226Ra budget is likely mainly controlled by clay minerals. Therefore, the variations in the 238U-234U-230Th-232Th system in the sediments of the Gandak river cannot simply be interpreted as the result of fractionation due to chemical transformation of the bulk sediment during its transport within the alluvial plain and/or the result of radioactive decay. Consequently, they cannot be used to infer long sediment transport times within the Gandak plain (10-100 ka), as previously proposed. Such analytical and interpretative artifacts are certainly not specific to the present study on the Gandak basin. These issues will certainly be encountered anytime this technique is applied to alluvial systems in which the U and Th budgets of the sediments are influenced by ;heavy; minerals that can be sorted during the transport of sediments within the plain.

Sediment Budgeting in Dam-Affected Rivers: Assessing the Influence of Damming, Tributaries, and Alluvial Valley Sediment Storage on Sediment Regimes

NASA Astrophysics Data System (ADS)

Wilcox, A. C.; Dekker, F. J.; Riebe, C. S.

2014-12-01

Although sediment supply is recognized as a fundamental driver of fluvial processes, measuring how dams affect sediment regimes and incorporating such knowledge into management strategies remains challenging. To determine the influences of damming, tributary supply, and valley morphology and sediment storage on downstream sediment supply in a dryland river, the Bill Williams River (BWR) in western Arizona, we measured basin erosion rates using cosmogenic nuclide analysis of beryllium-10 (10Be) at sites upstream and downstream of a dam along the BWR, as well as from tributaries downstream of the dam. Riverbed sediment mixing calculations were used to test if the dam, which blocks sediment supply from the upper 85% of the basin's drainage area, increases the proportion of tributary sediment to residual upstream sediment in mainstem samples downstream of the dam. Erosion rates in the BWR watershed are more than twice as large in the upper catchment (136 t km-2 yr-1) than in tributaries downstream of Alamo Dam (61 t km-2 yr-1). Tributaries downstream of the dam have little influence on mainstem sediment dynamics. The effect of the dam on reducing sediment supply is limited, however, because of the presence of large alluvial valleys along the mainstem BWR downstream of the dam that store substantial sediment and mitigate supply reductions from the upper watershed. These inferences, from our 10Be derived erosion rates and mixing calculations, are consistent with field observations of downstream changes in bed material size, which suggest that sediment-deficit conditions are restricted to a 10 km reach downstream of the dam, and limited reservoir bathymetry data. Many studies have suggested that tributary sediment inputs downstream of dams play a key role in mitigating dam-induced sediment deficits, but here we show that in a dryland river with ephemeral tributaries, sediment stored in alluvial valleys can also play a key role and in some cases trumps the role of tributaries.

Soils on raised marine terraces in the Metaponto area, S Italy: not a simple chronosequence

NASA Astrophysics Data System (ADS)

Sauer, Daniela; Al-Sharif, Riyad; Wagner, Stephen; Scarciglia, Fabio; Deffontaines, Benoît; Benvenuti, Marco; Carnicelli, Stefano; Brückner, Helmut

2015-04-01

A sequence of Middle and Late Pleistocene raised marine terraces stretches along the Gulf of Taranto, S Italy, for more than 65 km from Rocca Imperiale, Calabria, in the SW to Taranto, Apulia, in the NE, in an approximately 25 km wide belt. The terraces formed as a result of the interplay between sea-level fluctuations and regional tectonic uplift over a time-span of ca. 780 ka. They were selected for establishing a soil chronosequence, in order to analyse rates of soil-forming processes in the central Mediterranean region. Indeed, several general trends of soil formation with terrace age were identified. For example, soil thickness and Fed/Fet ratios increase, while the weathering ratio (Ca+Mg+K+Na)/Al decreases with assumed terrace age. These changes could be best described by power functions (R2 = 0.88 for soil thickness, R2 = 0.87 for Fed/Fet, and R2 = 0.96 for (Ca+Mg+K+Na)/Al). However, closer examination revealed that the soils did not simply form in the marine gravel bodies but in various kinds of sediments. The development of the landscape along the Gulf of Taranto turned out to be much more complex than previously expected. Sediment-soil successions exposed in several gravel quarries reveal that each terrace, after its original formation, was exposed to changing conditions in terms of climate, vegetation, level of erosion base (related to sea-level oscillations and/or tectonics), and other environmental factors during the Pleistocene and Holocene periods. As a result, it was subject to (i) further geomorphological and sedimentological evolution, including incision, denudation, deposition of alluvial sediments, and accumulation of colluvial deposits, in parts due to natural processes and in parts due to human activity; (ii) various directions and rates of soil development, corresponding to changing environmental conditions during glacial and interglacial periods. In some cases, there is evidence for a period of soil formation in the marine deposits prior to the deposition of the alluvial sediments. For example, a several metres thick marine gravel body, overlain by a layer of alluvial sandy-loamy sediments, is exposed in a gravel quarry on terrace T2 (assumed to have accumulated during MIS 5c). The boundary between the two sediment packages is very sharp and wavy, indicating a period of incision into the gravel body prior to the deposition of the alluvial sediments. Based on these observations, the following chronological sequence of events is assumed for this site: 1) accumulation of the gravel body in a delta environment during MIS 5c; 2) period of soil formation during late MIS 5c, after the surface of the gravel body had fallen dry; 3) incision of creeks, cutting channels into the gravel body as sea level dropped during MIS 5b; 4) sea-level rise during MIS 5a, not reaching the same level as during MIS 5c due to progressing regional uplift in the meantime; wave action of the MIS 5a sea removed part of the MIS 5c gravel body and cut a cliff into it, thus shaping the seaward edge of terrace T2; 5) accumulation of alluvial deposits in the previously incised channels and on top of the erosional gravel-body surface during MIS 5a because of the raised erosion base level; 6) incorporation of sandy sediments from the near-by MIS 5a beach, possibly with some contribution from temporarily dry beds of the nearby torrential rivers, into the alluvial deposits. Similarly complex sediment successions can be observed in several exposures. In addition, in some locations up to several metres of loess-like sediments are exposed. They probably accumulated during glacial periods, being blown out from the wide, temporarily dry river beds and from the exposed shelf. These observations led to a more differentiated reconstruction of the evolution of the landscape and soils in the Metaponto area.

Effects of Coarse Legacy Sediment on Rivers of the Ozark Plateaus and Implications for Native Mussel Fauna

NASA Astrophysics Data System (ADS)

Erwin, S. O.; Jacobson, R. B.; Eric, A. B.; Jones, J. C.; Anderson, B. W.

2015-12-01

Perturbations to sediment regimes due to anthropogenic activities may have long lasting effects, especially in systems dominated by coarse sediment where travel times are relatively long. Effectively evaluating management alternatives requires understanding the future trajectory of river response at both the river network and reach scales. The Ozark Plateaus physiographic province is a montane region in the interior US composed primarily of Paleozoic sedimentary rock. Historic land-use practices around the turn of the last century accelerated delivery of coarse sediment to river channels. Effects of this legacy sediment persist in two national parks, Ozark National Scenic Riverways, MO and Buffalo National River, AR, and are of special concern for management of native mussel fauna. These species require stable habitat, yet they occupy inherently dynamic environments: alluvial rivers. At the river-network scale, analysis of historical data reveals the signature of sediment waves moving through river networks in the Ozarks. Channel planform alternates between relatively stable, straight reaches, and wider, multithread reaches which have been more dynamic over the past several decades. These alternate planform configurations route and store sediment differently, and translate into different patterns of bed stability at the reach scale, which in turn affects the distribution and availability of habitat for native biota. Geomorphic mapping and hydrodynamic modeling reveal the complex relations between planform (in)stability, flow dynamics, bed mobility, and aquatic habitat in systems responding to increased sediment supply. Reaches that have a more dynamic planform may provide more hydraulic refugia and habitat heterogeneity compared to stable, homogeneous reaches. This research provides new insights that may inform management of sediment and mussel habitat in rivers subject to coarse legacy sediment.

A dam in the drylands: Effects of soil geomorphic actions on a mediterranean alluvial scrubland and the endangered Santa Ana woolly star (Eriastrum densifolium spp. sanctorum)

NASA Astrophysics Data System (ADS)

Hernandez, R. R.; Sandquist, D. R.

2017-12-01

When dams preclude natural flow, maintenance of river ecosystems adapted to infrequent, catastrophic floods poses unique challenges. Further, riparian mediterranean ecosystems with high inter-annual and seasonal precipitation variability, coupled with complicated patterns of biotic and abiotic heterogeneity, intensify challenges for management under disrupted flow regimes. In this study, we evaluated the impact of six unique soil geomorphic actions on the rare Riversidian alluvial fan sage scrub plant community, which includes the endangered Santa Ana River woolly star (Eriastrum densifolium spp. sanctorum [Eds]) after 5, 7.5, and 13 years of response. We implemented a complete randomized block design, with each block incorporating six geomorphic treatments: cleared, diked, cut, filled (10 cm soil), filled (20 cm soil), and filled (30 cm soil), mimicking one of more physical disturbance process occurring after a natural flood event. We performed native and exotic plant community surveys on full plots in summer 2006, representing 7.5 years of response from the original 1999 disturbance, and on (re-disturbed half) plots in fall 2012, representing (5 years) 13 years of response. We found that recruitment of Eds into late-successional (i.e., control) plots is highly limited (0.0, 4.1, and 2.5% cover) after 5, 7.5, and 13 years, respectively, with implications for the persistence of this species, whereas the cut treatment showed significantly higher cover of Eds (25.3, 53.4, 14.3%, respectively). Our results also suggest that exotic annual grasses may inhibit Eds and other Riversidian alluvial fan sage scrub plant community members under a disrupted flow regime but that soil geomorphic treatment of late-successional habitat can be effective in facilitating Eds and Riversidian alluvial fan sage scrub establishment.

Dynamics of 30 large channel bars in the Lower Mississippi River in response to river engineering from 1985 to 2015

NASA Astrophysics Data System (ADS)

Wang, Bo; Xu, Y. Jun

2018-01-01

Channel bars are a major depositional feature in alluvial rivers and their morphodynamics has been investigated intensively in the past several decades. However, relatively less is known about how channel bars in alluvial rivers respond to river engineering and regulations. In this study, we assessed 30-yr morphologic changes of 30 large emerged bars located in a 223 km reach of the highly regulated Lower Mississippi River from Vicksburg, Mississippi, to the Mississippi-Atchafalaya River diversion. Landsat imagery and river stage data between 1985 and 2015 were utilized to characterize bar morphologic features and quantify decadal changes. Based on bar surface areas estimated with the satellite images at different river stages, a rating curve was developed for each of the 30 bars to determine their volumes. Results from this study show that the highly regulated river reach favored the growth of mid-channel and attached bars, while more than half of the point bars showed degradation. Currently, the mid-channel and attached bars accounted for 38% and 34% of the total volume of the 30 bars. The average volume of a single mid-channel bar is over two times that of an attached bar and over four times that of a point bar. Overall, in the past three decades, the total volume of the studied 30 bars increased by 110,118,000 m3 (41%). Total dike length in a dike field was found mostly contributing to the bar volume increase. Currently, the emerged volume of the 30 bars was estimated approximately 378,183,000 m3. The total bar volume is equivalent to 530 million metric tons of coarse sand, based on an average measured bulk density of 1.4 t/m3 for the bar sediment. The findings show that these bars are large sediment reservoirs.

Enhancements to the Mississippi Embayment Regional Aquifer Study (MERAS) groundwater-flow model and simulations of sustainable water-level scenarios

USGS Publications Warehouse

Clark, Brian R.; Westerman, Drew A.; Fugitt, D. Todd

2013-01-01

Arkansas continues to be one of the largest users of groundwater in the Nation. As such, long-term planning and management are essential to ensure continued availability of groundwater and surface water for years to come. The Mississippi Embayment Regional Aquifer Study (MERAS) model was developed previously as a tool to evaluate groundwater availability within the Mississippi embayment, which encompasses much of eastern Arkansas where the majority of groundwater is used. The Arkansas Water Plan is being updated for the first time since 1990 and serves as the State’s primary, comprehensive water-resources planning and guidance document. The MERAS model was selected as the best available tool for evaluation of specific water-use pumping scenarios that are currently being considered by the State of Arkansas. The model, developed as part of the U.S. Geological Survey Groundwater Resources Program’s assessment of the Nation’s groundwater availability, is proving to be invaluable to the State as it works toward development of a sustained yield pumping strategy. One aspect of this investigation was to evaluate multiple methods to improve the match of observed to simulated groundwater levels within the Mississippi River Valley alluvial and middle Claiborne (Sparta) aquifers in the MERAS model. Five primary methods were evaluated: (1) explicit simulation of evapotranspiration (ET), (2) upgrade of the Multi-Node Well (MNW2) Package, (3) geometry improvement within the Streamflow Routing (SFR) Package, (4) parameter estimation of select aquifer properties with pilot points, and (5) modification of water-use estimates. For the planning purposes of the Arkansas Water Plan, three scenarios were developed to evaluate potential future conditions: (1) simulation of previously optimized pumping values within the Mississippi River Valley alluvial and the middle Claiborne aquifers, (2) simulated prolonged effects of pumping at average recent (2000–5) rates, and (3) simulation of drawdown constraints on most pumping wells. The explicit simulation of ET indicated little, if any, improvement of model fit at the expense of much longer simulation time and was not included in further simulations. Numerous attempts to fully utilize the MNW2 Package were unsuccessful in achieving model stability, though modifications made to the water-use dataset remained intact. Final improvements in the residual statistics may be attributed to a single method, or a cumulative effect of all other methods (geometry improvement with the SFR Package, parameter estimation with pilot points, and modification of water-use estimates) attempted. The root mean squared error (RMSE) for all observations in the model is 22.65 feet (ft) over a range in observed hydraulic head of 741.66 ft. The RMSE for water-level observations in the Mississippi River Valley alluvial aquifer is 14.14 ft (an improvement of almost 3 ft) over a range in observed hydraulic head of 297.25 ft. The RMSE for the Sparta aquifer is 32.02 ft (an improvement of approximately 3 ft) over a range in observed hydraulic head of 634.94 ft. Three scenarios were developed to utilize a steady-state version of the MERAS model. Scenario 1 was developed to use pumping values resulting from the optimization of baseline rates (typically 1997 pumping rates) from previous optimization modeling of the alluvial aquifer and the Sparta aquifer. Scenario 2 was developed to evaluate the prolonged effects of pumping from the alluvial aquifer at recent pumping rates. Scenario 3A was designed to evaluate withdrawal limits from the alluvial aquifer by utilizing drawdown constraints equal to an altitude of approximately 50 percent of the predevelopment saturated thickness of the alluvial aquifer or 30 ft above the bottom of the alluvial aquifer, whichever was greater. The results of scenario 1 indicate large water-level declines throughout the area of the alluvial aquifer, regardless of the substitution of the optimized pumping values from earlier model simulations. The results of scenario 2 also indicate large areas of water-level decline, as compared to half of the saturated thickness, throughout the alluvial aquifer. The results of scenario 3A reveal some effects from the inclusion of multiple aquifers in a single simulation. The initial configuration of scenario 3A resulted in water levels well below the defined drawdown constraint, and some areas of depleted aquifer (water levels that are near or below the bottom of the aquifer) in east-central Arkansas. A fourth simulation (scenario 3B) was configured to apply the same drawdown constraints from the alluvial aquifer wells to the Sparta aquifer wells in the depleted area. These drawdown constraints reduce leakage from the alluvial aquifer to the underlying Sparta aquifer. This configuration did not produce depleted areas within the alluvial aquifer. Scenarios 3A and 3B indicate that even when pumping is limited in the alluvial aquifer, water levels in the alluvial aquifer may continue to decline in some areas because of pumping in the underlying Sparta aquifer.

The origin of groundwater in Zhangye Basin, northwestern China, using isotopic signature

NASA Astrophysics Data System (ADS)

Chen, Jiansheng; Liu, Xiaoyan; Sun, Xiaoxu; Su, Zhiguo; Yong, Bin

2014-03-01

Zhangye Basin, in arid northwestern China, has recently been repeatedly flooded by rising groundwater. Isotope signatures of sampled waters gained insight into the recharge source of the groundwater. The summer Heihe River water and most of the spring water in Zhangye and Yongchang basins plotted above the global meteoric water line (GMWL) on the δ18O-δD plot. The spring water had R/Ra ratio >1, low TDS and high tritium, which indicates origin from Qilian Mountain glacier meltwater. The groundwater of Qilian Mountains was transported to the Hexi Corridor (in which Zhangye Basin is located) through underground fault zones. Additionally, some of the groundwater in the alluvial plain, and all spring water surrounding Zhangye Basin, plotted below the GMWL on the δ18O-δD plot along an evaporation line, and had R/Ra ratio < 1 and high TDS. It is proposed that the Tibetan rivers or lakes source the Hexi Corridor groundwater through either the NE-trending or NW-trending buried fault zones. The isotopic signatures presented as part of this study rule out the conventional viewpoint that groundwater of the Zhangye Basin was recharged by local precipitation and infiltration of Heihe River water on the alluvial plain.

Physical and Chemical Connectivity of Streams and Riparian Wetlands to Downstream Waters: A Synthesis

EPA Science Inventory

Streams, riparian areas, floodplains, alluvial aquifers, and downstream waters (e.g., large rivers, lakes, and oceans) are interconnected by longitudinal, lateral, and vertical fluxes of water, other materials, and energy. Collectively, these interconnected waters are called fluv...

Controls on sinuosity in the sparsely vegetated Fossálar River, southern Iceland

NASA Astrophysics Data System (ADS)

Ielpi, Alessandro

2017-06-01

Vegetation exerts strong controls on fluvial sinuosity, providing bank stability and buffering surface runoff. These controls are manifest in densely vegetated landscapes, whereas sparsely vegetated fluvial systems have been so far overlooked. This study integrates remote sensing and gauging records of the meandering to wandering Fossálar River, a relatively steep-sloped (< 2.5%) Icelandic river featuring well-developed point bars (79%-85% of total active bar surface) despite the lack of thick, arborescent vegetation. Over four decades, fluctuations in the sinuosity index (1.15-1.43) and vegetation cover (63%-83%) are not significantly correlated (r = 0.28, p > 0.05), suggesting that relationships between the two are mediated by intervening variables and uncertain lag times. By comparison, discharge regime and fluvial planform show direct correlation over monthly to yearly time scales, with stable discharge stages accompanying the accretion of meander bends and peak floods related to destructive point-bar reworking. Rapid planform change is aided by the unconsolidated nature of unrooted alluvial banks, with recorded rates of lateral channel-belt migration averaging 18 m/yr. Valley confinement and channel mobility also control the geometry and evolution of individual point bars, with the highest degree of spatial geomorphic variability recorded in low-gradient stretches where lateral migration is unimpeded. Point bars in the Fossálar River display morphometric values comparable to those of other sparsely vegetated rivers, suggesting shared scalar properties. This conjecture prompts the need for more sophisticated integrations between remote sensing and gauging records on modern rivers lacking widespread plant life. While a large volume of experimental and field-based work maintains that thick vegetation has a critical role in limiting braiding, thus favouring sinuosity, this study demonstrates the stronger controls of discharge regime and alluvial morphology on sparsely vegetated sinuous rivers.

The megageomorphology of the radar rivers of the eastern Sahara

NASA Technical Reports Server (NTRS)

Mccauley, John F.; Breed, Carol S.; Schaber, Gerald G.

1986-01-01

The Eastern Sahara is devoid of surface drainage; this unusual characteristic distinguishes its morphology from that of most other desert regions where running water dominates landscape development. A map derived from SIR-A/B and LANDSAT images and the literature, shows the major presently known paleodrainages in the Eastern Sahara. This compilation permits consideration of the key questions: Where did the radar rivers come from and where did they go? Analysis of SIR-A data led McCauley et al. to suggest that the radar rivers, because of their southwestward trends, once flowed into the Chad basin. This key North African feature is a regional structural low formed in the Early Cretaceous in response to initial opening of the South Atlantic. The problem of the origin of headwaters for the radar rivers was less tractable. The idea that the source areas of the radar rivers might originally have been the same as those later captured by the Nile was proposed tentatively. A more extensive review of the Cenozoic tectonic history of North Africa reveals no reason now to suppose that the Central African tributaries of the present Nile were ever connected to the large alluvial valleys in southwestern Egypt and northwestern Sudan. formed in the Early Cretaceous in response to initial opening of the South Atlantic. The problem of the origin of headwaters for the radar rivers was less tractable. The idea that the source areas of the radar rivers might originally have been the same as those (The Ethiopian Highlands) later captured by the Nile was proposed tentatively. A more extensive review of the Cenozoic tectonic history of North Africa reveals no reason now to support that the Central African tributaries of the present Nile were ever connected to the large alluvial valleys in southwestern Egypt and northwestern Sudan.

Geomorphic Parameters for Developing a Hydrologic Model to Infer Holocene Climate Variability, Middle Snake River near Bliss, Idaho

NASA Astrophysics Data System (ADS)

Bullard, T. F.; Bacon, S. N.; Kimball, V. R.

2015-12-01

The geomorphology and stratigraphy preserved in a canyon reach of the Middle Snake River provide model parameter constraints for estimating Holocene paleohydrology. Channel constrictions, which acted as hydraulic weirs throughout the Holocene, were created in this reach by the Bonneville Flood (~17.5 ka) that left very large (>10 m) slabs of basalt and 2-3 m diameter boulder deposits near the canyon floor. Post-Bonneville Flood landforms and deposits that formed during the Holocene are situated less than ~30 m above river level (arl) in this reach and include fluvial and boulder terraces, alluvial fans, and incised tributary alluvial units. Relative topographic position of these geomorphic features, cross-cutting relations, multiple buried soils, depositional and erosional contacts, and radiocarbon dates from terraces (Qt) and alluvial fans provide a geomorphic and stratigraphic framework and a Holocene chronology for this area. The relative stratigraphic position of a massive silty sand that overlies Bonneville Flood gravel in Qt5 (~20 m arl) and Qt4 (~10 m arl) deposits and comprises all of Qt3 (~5 m arl) deposits indicates changes in Holocene discharge; longitudinal profiles of fluvial terraces graded to hydraulic constrictions provide reasonable estimates of paleo-stage. Fifteen radiocarbon dates yielded ages of ~8670 and ~3500 cal yr BP for Qt4 deposits and ~1100 and ~100 cal yr BP for Qt3 deposits and help define periods of episodic cutting and filling. Timing of Qt4 and Qt3 cut-and-fill episodes and alluvial fan formation correlates well with Holocene global and regional paleoclimate events inferred from Great Basin lake histories including wet periods from ~9.0 to 8.0 ka and ~4.2 to 2.5 ka, the Medieval Climatic Anomaly (~1.2 to 0.8 ka), and the Little Ice Age (~0.3 to 0.6 ka). The fluvial geomorphology documented in this study will be used to develop a watershed-scale hydrologic model to infer paleoprecipitation in the region during the Holocene.

An overview of historical channel adjustment and selected hydraulic values in the Lower Sabine and Lower Brazos River Basins, Texas and Louisiana

USGS Publications Warehouse

Heitmuller, Franklin T.; Greene, Lauren E.; John D. Gordon, John D.

2010-01-01

The Sabine and Brazos are alluvial rivers; alluvial rivers are dynamic systems that adjust their geometry in response to changes in streamflow (discharge) and sediment load. In fluvial geomorphology, the term 'channel adjustment' refers to river channel changes in three geometric dimensions: (1) channel slope (profile); (2) the outline or shape, such as meandering or braided, projected on a horizontal plane (planform); and (3) cross-sectional form (shape). The primary objective of the study was to investigate how the channel morphology of these rivers has changed in response to reservoirs and other anthropogenic disturbances that have altered streamflow and sediment load. The results of this study are expected to aid ecological assessments in the lower Sabine River and lower Brazos River Basins for the Texas Instream Flow Program. Starting in the 1920s, several dams have been constructed on the Sabine and Brazos Rivers and their tributaries, and numerous bridges have been built and sometimes replaced multiple times, which have changed the natural flow regime and reduced or altered sediment loads downstream. Changes in channel geometry over time can reduce channel conveyance and thus streamflow, which can have adverse ecological effects. Channel attributes including cross-section form, channel slope, and planform change were evaluated to learn how each river's morphology changed over many years in response to natural and anthropogenic disturbances. Climate has large influence on the hydrologic regimes of the lower Sabine and lower Brazos River Basins. Equally important as climate in controlling the hydrologic regime of the two river systems are numerous reservoirs that regulate downstream flow releases. The hydrologic regimes of the two rivers and their tributaries reflect the combined influences of climate, flow regulation, and drainage area. Historical and contemporary cross-sectional channel geometries at 15 streamflow-gaging stations in the lower Sabine and lower Brazos River Basins were evaluated. An in-depth discussion of results from streamflow-gaging station 08028500 Sabine River near Bon Weir, Tex., is featured here as an example of the analyses that were done at each station.

Determinism in fish assemblages of floodplain lakes of the vastly disturbed Mississippi Alluvial Valley

USGS Publications Warehouse

Miranda, L.E.; Lucas, G.M.

2004-01-01

The Mississippi Alluvial Valley between southern Illinois and southern Louisiana contains hundreds of floodplain lakes, most of which have been adversely affected by landscape modifications used to control flooding and support agriculture. We examined fish assemblages in lakes of this region to determine whether deterministic patterns developed in relation to prominent abiotic lake characteristics and to explore whether relevant abiotic factors could be linked to specific assemblage structuring mechanisms. The distributions of 14 taxa in 29 lakes were governed primarily by two gradients that contrasted assemblages in terms of lake area, lake elongation, and water clarity. The knowledge of whether a lake was clear or turbid, large or small, and long or short helped determine fish assemblage characteristics. Abiotic factors influenced fish assemblage structures, plausibly through limitations on foraging and physiological tolerances. Determinism in assemblage organization of floodplain lakes relative to recurrence in physicochemical features has been documented for unaltered rivers. Whereas the Mississippi Alluvial Valley has been subjected to vast anthropogenic disturbances and is not a fully functional floodplain river, fish assemblages in its floodplain lakes remain deterministic and organized by the underlying factors that also dictate assemblages in unaltered rivers. In advanced stages of lake aging, fish assemblages in these lakes are expected to largely include species that thrive in turbid, shallow systems with few predators and low oxygen concentrations. The observed patterns related to physical characteristics of these lakes suggest three general conservation foci, including (1) watershed management to control erosion, (2) removal of sediments or increases in water level to alleviate depth reductions and derived detriments to water physicochemistry, and (3) management of fish populations through stockings, removals, and harvest regulations.

Factors influencing the composition of detrital heavy mineral suites in Holocene sands of the Apure River drainage basin, Venezuela

USGS Publications Warehouse

Morton, Andrew C.

1993-01-01

Heavy mineral assemblages in rivers in the Apure River drainage basin of Venezuela and Colombia closely reflect the nature of the source regions, which lie in the Andean orogenic terranes to the west and northwest. The Caribbean Mountains, largely composed of greenschist-facies pelites, phyllites, carbonates, and metavolcanics, supply assemblages dominated by epidote and calcic amphibole. Minor amounts of the high-pressure index minerals glaucophane and lawsonite indicate the presence of blueschistfacies rocks, reflecting the origin of the Caribbean Mountains by subduction-related tectonism. The northern Mérida Andes, which comprise basement gneisses and granites overlain by unmetamorphosed to low-grade metamorphosed clastics, supply two types of assemblage reflecting these two lithological types: garnet-sillimanite-staurolite-amphibole suites from the basement rocks, and epidote-amphibole suites from the overlying cover sequence. The southern Mérida Andes supply stable heavy mineral suites reflecting recycling from the extensive unmetamorphosed sandstones that occur at outcrop. By considering suites from different physiographical provinces, the effects of short-term alluvial storage in the Llanos on heavy mineral assemblages have been evaluated. Weathering during alluvial storage appears to be effective in modifying the apatite-tourmaline ratio, which shows a steady, marked decline with distance from the mountain front, resulting from the removal of apatite during weathering. Clinopyroxene and garnet may also show evidence of loss through weathering, although the trends are poorly constrained statistically. Epidote and amphibole proportions remain essentially constant, possibly through a balance between loss through weathering and continual resupply from the breakdown of rock fragments. In general, the heavy mineral assemblages are less affected than the bulk mineralogy by alluvial storage on the Llanos.

Uplifted Yellow river terraces across the Haiyuan fault, China and their implications to geometrical complexity of strike-slip fault system

NASA Astrophysics Data System (ADS)

Liu, J.; van der Woerd, J.; Li, Z.; Klinger, Y.; Matrau, R.; Shao, Y.; Zhang, J.; Wang, P.

2016-12-01

Geometrical complexities and discontinues, such as fault bends, splays and step-overs, are common along large strike-slip faults. Numerical and observational studies show that geometrical complexities above some threshold degree may inhibit thoroughgoing rupture, limiting rupture length and the size of the resulting earthquake. Studying the fine structure and long-term evolution of fault step-overs would help us better understand their effect on earthquake ruptures. In this study, we focus on a prominent geometrical "knot" on the left-lateral Haiyuan fault, where the fault curves with multi-strand splays bounding the Mijia Shan-Hasi Shan ranges. Incidentally, the Yellow river flows between the Mijia Shan and Hasi Shan and cuts a deep gorge when crossing the fault. On the western bank of the river, a series of at least twelve levels of fluvial strath terraces perch above river bed, and are capped with no more than 5 meters of alluvial deposits. We measured the terrace heights above river bed, using RTK and UAV surveys. We collected quartz-rich pebbles of yellow river gravel for cosmogenic radio nuclide (CRN), and silt layers within gravel and the overlying loess cap for optimally stimulated luminescence (OSL) dating to constrain the terrace formation ages. Quartz-rich pebbles were sampled both in hand-dug pit for depth-profile method and surface samples on terrace surfaces. The CRN age results were corrected in terms of inheritance and shielding by loess. The dates and heights of serial terraces yielded an average uplift rate of 2±0.34 mm/yr, which represents the late Quaternary uplifting rate of the Mijia Shan. The uplift of the Mijia Shan-Hasi Shan may result from the oblique shear of positive flower in the deep crust of the left-lateral Haiyuan fault. We further speculate that with progressively uplifted mountain ranges, the active fault trace shifts with time among the multi-strands of the fault system. In addition, the coincidence of prominent uplifted mountains at the position where the Yellow river cut across the left-lateral strike-slip fault suggests that Yellow river may play a role in enhancing the uplifting rate, though efficient mass unloading.

Reconnaissance of surface-water quality in the North Platte Natural Resources District, western Nebraska, 1993

USGS Publications Warehouse

Steele, G.V.; Cannia, J.C.

1997-01-01

In 1993, the U.S. Geological Survey and the North Platte Natural Resources District began a 3-year study to determine the geohydrology and water quality of the North Platte River alluvial aquifer near Oshkosh, Garden County, Nebraska. The objectives of the study were to determine the geohydrologic properties of the North Platte River alluvial aquifer, to establish a well network for long- term monitoring of concentrations of agricultural chemicals including nitrate and herbicides, and to establish baseline concentrations of major ions in the ground water. To meet these objectives, monitor wells were installed at 11 sites near Oshkosh. The geohydrologic properties of the aquifer were estimated from water-level measurements at selected irrigation wells located in the study area and short- term constant-discharge aquifer tests at two monitor wells. Water samples were collected bimonthly and analyzed for specific conductance, pH, water temperature, dissolved oxygen, and nutrients including dissolved nitrate. Samples were collected semiannually for analysis of major ions, and annually for triazine and acetamide herbicides. Evaluation of the aquifer-test data indicates the hydraulic conductivities of the North Platte River alluvial aquifer range between 169 and 184 feet per day and transmissivities ranged from 12,700 to 26,700 feet-squared per day. The average specific yield for the alluvial aquifer, based on the two aquifer tests, was 0.2. Additional hydrologic data for the alluvial aquifer include a horizontal gradient of about 0.002 foot per foot and estimated ground- water flow velocities of about 0.1 to 1.8 feet per day. Evaluation of the water-quality data indicates that nitrate concentrations exceed the U.S. Environmental Protection Agency's (USEPA) Maximum Contamination Level of 10 milligrams per liter for drinking water in areas to the east and west of Oshkosh. In these areas, nitrate concentrations generally are continuing to rise. West of Oshkosh the highest concentrations are now exceeding 50 milligrams per liter. With the exception of one sample, nitrate concentrations exceeding the Maximum Contamination Level were not detected in three wells used to monitor the ground water flowing into and out of the study area, nor in a monitor well located near a municipal well. Results of the study also indicate that an influx of water from Lost Creek Valley, north of the study area, may be mixing with ground water near Oshkosh and diluting concentrations of nitrate.

The Dynamics of Coarse Sediment Transfer in an Upland Bedrock River

NASA Astrophysics Data System (ADS)

Warburton, J.; Hardy, R. J.; Ferguson, R. I.; Cray, A.

2010-12-01

Bedrock channels in UK environments have received relatively little attention despite their importance within upland river systems and their influence on controlling the conveyance of sediment downstream. This poster describes the transfer of coarse sediment through Trout Beck, an upland bedrock reach in the North Pennines, UK. The transport of coarse sediment has been quantified through field monitoring of sediment characteristics, repeat magnetic tracer surveys and in-situ bed load impact sensors. This was carried out in conjunction with surveys of channel morphology (using terrestrial laser scanning and repeat dGPS measurements) and continuous flow monitoring. The interaction between mobile sediment and channel morphology is partly conditioned by the extent of alluvial sediment cover. Sediment storage is patchy with partially alluvial and alluvial sections of the channel, interspersed with bedrock reaches containing very little sediment except in hydraulically sheltered sites. There are notable differences in sediment dynamics between these different sections of the river channel which have a considerable influence on conveyance of sediment through the reach. In bedrock sections the low resistance to flow and stable channel boundaries result in little sediment storage and during periods when flow is competent there is downstream conveyance of the full grain-size distribution of sediment. Detailed morphological survey has provided the necessary boundary conditions, along with the flow data, to apply a one-dimensional hydraulic model (HEC-RAS) of the bedrock study reach. The modelling results have quantified the hydraulic regime of the channel. Using local shear stress as a proxy for sediment transport, sediment transport potential for the dominant grain-size distribution of the reach (16-256 mm) has been assessed for different locations in the channel. There are significant differences in the critical threshold of shear stress for sediment transport down the reach. Sediment which is transported through the bedrock reach will be deposited and stored, in the partially alluvial and alluvial sections of the channel. As the flow magnitude increases above the critical entrainment threshold, sediment transport potential increases throughout the whole channel until hydraulic conditions in the whole reach have the potential to transport sediment. Hence, sediment storage in the channel fluctuates through time depending on the frequency of ‘channel clearing’ floods; however, the overall pattern (template) of sedimentation is predictable based on local hydraulics. By combining the field and modelling approaches an improved understanding of the flow thresholds and spatial variations in sediment transport, in an upland bedrock channel, has been achieved.

Reaction and relaxation in a coarse-grained fluvial system following catchment-wide disturbance

NASA Astrophysics Data System (ADS)

Tunnicliffe, Jon; Brierley, Gary; Fuller, Ian C.; Leenman, Anya; Marden, Mike; Peacock, Dave

2018-04-01

The Waiapu River catchment (drainage area of 1734-km2) is one of the most prolific conveyors of sediment in the world, annually delivering roughly 35 Mt of fine material to the ocean from eroding gullies, hillslopes, and reworked sediment on valley floors. Tectonic and geologic influences, in combination with a dynamic climate influenced by tropical cyclones and clearance of vegetation from steep hillslopes, predisposes this region to high rates of erosion. The bedload sediment regime of the river is strongly influenced by several exceptionally large gullies and gully complexes that produce a coarse-grained, poorly sorted sediment mixture. Rapid abrasion and breakdown leads to high rates of suspended sediment yield. A wave of bedload material, manifesting as elevated bed levels and significant widening of active alluvial fills, has been triggered by large inputs of hillslope material from a few key tributary catchments following Cyclone Bola in 1988. We review the evidence for the relaxation process of the sedimentary system in the subsequent 29 years, appraising some of the legacy effects that may endure, as associated with reworking of the considerable alluvial stores within the Waiapu system. We use Structure-from-Motion (SfM) techniques and archival aerial photos to quantify changes in sediment storage at the base of two major gully systems in recent decades. A record of over 850 cross section surveys at 62 sites on 10 rivers throughout the catchment (1958-2017) indicates recent transition from a trend of continuous accumulation to downcutting and remobilisation of valley-bottom deposits. The channel cross sections provide a minimum estimate of sediment flux from source areas to the lower reaches of the river, giving a rudimentary but spatially extensive picture of the wave of material cascading through the drainage network. The largest impacts occur in the upper steepland rivers, closest to the landslide-derived sediment supply. Transport rates here, as inferred from cross section change, are at a maximum during an aggradational phase following Cyclone Bola then taper off, despite the large sediment accumulations remaining in the system. As of 2017, the river is in the process of incising the upper extents of this deposit on a trajectory of recovery toward pre-Bola conditions. The compilation of cross section data provides us with new insights into the sensitivity of particular sites in the landscape, as well as the changing relationship between reach sediment storage and transport rates during the response and relaxation phase of a major disturbance in a large catchment.

Cultural Resources Overview of the Proposed Black Cypress and Marshall Reservoirs.

DTIC Science & Technology

1981-07-21

effects that the Red River raft had on alluviation and flood plain sites in the study area. The results of these studies should be incorporated into the...northwest Louisiana parish . The basin consists of the watersheds of three major streams which are called bayous in their lower sections and creeks in...Jefferson became the westernmost and northernmost port which was easily accessible from the Red River (White 1964:54). The growth of Jefferson as a ?ort

Hydrologic information for land-use planning; Fairbanks vicinity, Alaska

USGS Publications Warehouse

Nelson, Gordon L.

1978-01-01

The flood plain on the Chena and Tanana Rivers near Fairbanks, Alaska, has abundant water in rivers and in an unconfined alluvial aquifer. The principal source of ground water is the Tanana River, from which ground water flows northwesterly to the Chena River. Transmissivity of the aquifer commonly exceed 100 ,000 sq ft. The shallow water table (less than 15 ft below land surface), high hydraulic conductivity of the sediments and cold soil give the flood plain a high susceptibility to pollution by onsite sewerage systems. The Environmental Protection Agency recommended maximum concentrations for drinking water may be exceeded in surface water for manganese and bacteria and in ground water for iron, manganese, and bacteria. Residents of the uplands obtain water principally from a widely-distributed fractured schist aquifer. The aquifer is recharged by local infiltration of precipitation and is drained by springs on the lower slopes and by ground-water flow to alluvial aquifers of the valleys. The annual base flow from basins in the uplands ranged from 3,000 to 100,000 gallons per acre; the smallest base flows occur in basins nearest the city of Fairbanks. The thick silt cover and great depth to the water table give much of the uplands a low susceptibility to pollution by onsite sewage disposal. Ground water is locally high in nitrate, arsenic, iron , and manganese. (Woodard-USGS)

Abiotic controls of emergent macrophyte density in a bedrock channel - The Cahaba River, AL (USA)

NASA Astrophysics Data System (ADS)

Vaughn, Ryan S.; Davis, Lisa

2015-10-01

Research examining bedrock channels is growing. Despite this, biotic-abiotic interactions remain a topic mostly addressed in alluvial systems. This research identified hydrogeomorphic factors operating at the patch-scale (100-102 m) in bedrock shoals of the Cahaba River (AL) that help determine the distribution of the emergent aquatic macrophyte, Justicia americana. Macrophyte patch density (number of stems/m2) and percent bedrock void surface area (rock surface area/m2 occupied by joints, fractures, and potholes) were measured (n = 24 within two bedrock shoals) using stem counts and underwater photography, respectively. One-dimensional hydrologic modeling (HEC-RAS 4.1.0) was completed for a section within a shoal to examine velocity and channel depth as controlling variables for macrophyte patch density. Results from binary logistic regression analysis identified depth and velocity as good predictors of the presence or absence of Justicia americana within shoal structures (depth p = 0.001, velocity p = 0.007), which is a similar finding to previous research conducted in alluvial systems. Correlation analysis between bedrock surface void area and stem density demonstrated a statistically significant positive correlation (r = 0.665, p = 0.01), elucidating a link between abiotic-biotic processes that may well be unique to bedrock channels. These results suggest that the amount of void space present in bedrock surfaces, in addition to localized depth and velocity, helps control macrophyte patch density in bedrock shoal complexes. The utility of geomorphology in explaining patch-scale habitat heterogeneity in this study highlights geomorphology's potential to help understand macrophyte habitat heterogeneity at the reach scale, while also demonstrating its promise for mapping and understanding habitat heterogeneity at the system scale.

A monoclinic, pseudo-orthorhombic Au-Hg mineral of potential economic significance in Pleistocene Snake River alluvial deposits of southeastern Idaho

USGS Publications Warehouse

Desborough, G.A.; Foord, E.E.

1992-01-01

A mineral with the approximate composition of Au94Hg6 - Au88Hg12 (atomic %) has been identified in Pleistocene Snake River alluvial deposits. The gold-mercury mineral occurs as very small grains or as polycrystalline masses composed of subhedral to nearly euhedral attached crystals. Vibratory cold-polishing techniques with 0.05-??m alumina abrasive for polished sections revealed a porous internal texture for most subhedral crystals after 48-72 hours of treatment. Thus, optical character (isotropic or anisotropic) could not be determined by reflected-light microscopy, and pore-free areas were too small for measurement of reflectance. X-ray-diffraction lines rather than individual reflections (spots), on powder camera X-ray films of unrotated spindles of single grains that morphologically appear to be single crystals, indicate that individual subhedral or euhedral crystals are composed of domains in random orientation. Thus, no material was found suitable for single-crystal X-ray diffraction studies. -from Authors

Drinking Water Quality Criterion - Based site Selection of Aquifer Storage and Recovery Scheme in Chou-Shui River Alluvial Fan

NASA Astrophysics Data System (ADS)

Huang, H. E.; Liang, C. P.; Jang, C. S.; Chen, J. S.

2015-12-01

Land subsidence due to groundwater exploitation is an urgent environmental problem in Choushui river alluvial fan in Taiwan. Aquifer storage and recovery (ASR), where excess surface water is injected into subsurface aquifers for later recovery, is one promising strategy for managing surplus water and may overcome water shortages. The performance of an ASR scheme is generally evaluated in terms of recovery efficiency, which is defined as percentage of water injected in to a system in an ASR site that fulfills the targeted water quality criterion. Site selection of an ASR scheme typically faces great challenges, due to the spatial variability of groundwater quality and hydrogeological condition. This study proposes a novel method for the ASR site selection based on drinking quality criterion. Simplified groundwater flow and contaminant transport model spatial distributions of the recovery efficiency with the help of the groundwater quality, hydrological condition, ASR operation. The results of this study may provide government administrator for establishing reliable ASR scheme.

Geological setting control of flood dynamics in lowland rivers (Poland).

PubMed

Wierzbicki, Grzegorz; Ostrowski, Piotr; Falkowski, Tomasz; Mazgajski, Michał

2018-04-27

We aim to answer a question: how does the geological setting affect flood dynamics in lowland alluvial rivers? The study area covers three river reaches: not trained, relatively large on the European scale, flowing in broad valleys cut in the landscape of old glacial plains. We focus on the locations where levees [both: a) natural or b) artificial] were breached during flood. In these locations we identify (1) the erosional traces of flood (crevasse channels) on the floodplain displayed on DEM derived from ALS LIDAR. In the main river channel, we perform drillings in order to measure the depth of the suballuvial surface and to locate (2) the protrusions of bedrock resistant to erosion. We juxtapose on one map: (1) the floodplain geomorphology with (2) the geological data from the river channel. The results from each of the three study reaches are presented on maps prepared in the same manner in order to enable a comparison of the regularities of fluvial processes written in (1) the landscape and driven by (2) the geological setting. These processes act in different river reaches: (a) not embanked and dominated by ice jam floods, (b) embanked and dominated by rainfall and ice jam floods. We also analyse hydrological data to present hydrodynamic descriptions of the flood. Our principal results indicate similarity of (1) distinctive erosional patterns and (2) specific geological features in all three study reaches. We draw the conclusion: protrusions of suballuvial bedrock control the flood dynamics in alluvial rivers. It happens in both types of rivers. In areas where the floodplain remains natural, the river inundates freely during every flood. In other areas the floodplain has been reclaimed by humans who constructed an artificial levee system, which protects the flood-prone area from inundation, until levee breach occurs. Copyright © 2018 Elsevier B.V. All rights reserved.

Herbicide and nitrate variation in alluvium underlying a cornfield at a site in Iowa County, Iowa

USGS Publications Warehouse

Kalkhoff, S.J.; Detroy, M.G.; Cherryholmes, K.; Kuzniar, R.L.

1992-01-01

A hydrologic investigation to determine vertical and seasonal variation of atrazine, alachlor, cyanazine, and nitrate at one location and to relate the variation to ground-water movement in the Iowa River alluvium was conducted in Iowa County, Iowa, from March 1986 to December 1987. Water samples were collected at discrete intervals through the alluvial sequence from the soil zone to the base of the aquifer. Alachlor, atrazine, and cyanazine were detected most frequently in the soil zone but also were present in the upper part of the alluvial aquifer. Alachlor was detected sporadically, whereas, atrazine, cyanazine, and nitrate were present throughout the year. In the alluvial aquifer, the herbicides generally were not detected during 1986 and were present in detectable concentrations for only a short period of time in the upper 1.6 meters of the aquifer during 1987. Nitrate was present throughout the alluvium and was stratified in the alluvial aquifer. The largest nitrate concentrations were detected in the middle part of the aquifer. Nitrate concentrations were variable only in the upper 2 meters of the aquifer. Vertical movement of herbicides and nitrate in the soil correlated with precipitation and degree of saturation. A clay layer retarded vertical movement of atrazine but not nitrate from the soil layer to the aquifer. Vertical movement could not account for the chemical variation in the alluvial aquifer.

Formation and failure of volcanic debris dams in the Chakachatna River valley associated with eruptions of the Spurr volcanic complex, Alaska

USGS Publications Warehouse

Waythomas, C.F.

2001-01-01

The formation of lahars and a debris avalanche during Holocene eruptions of the Spurr volcanic complex in south-central Alaska have led to the development of volcanic debris dams in the Chakachatna River valley. Debris dams composed of lahar and debris-avalanche deposits formed at least five times in the last 8000-10,000 years and most recently during eruptions of Crater Peak vent in 1953 and 1992. Water impounded by a large debris avalanche of early Holocene (?) age may have destabilized an upstream glacier-dammed lake causing a catastrophic flood on the Chakachatna River. A large alluvial fan just downstream of the debris-avalanche deposit is strewn with boulders and blocks and is probably the deposit generated by this flood. Application of a physically based dam-break model yields estimates of peak discharge (Qp) attained during failure of the debris-avalanche dam in the range 104 < Qp < 106 m3 s-1 for plausible breach erosion rates of 10-100 m h-1. Smaller, short-lived, lahar dams that formed during historical eruptions in 1953, and 1992, impounded smaller lakes in the upper Chakachatna River valley and peak flows attained during failure of these volcanic debris dams were in the range 103 < Qp < 104 m3 s-1 for plausible breach erosion rates. Volcanic debris dams have formed at other volcanoes in the Cook Inlet region, Aleutian arc, and Wrangell Mountains but apparently did not fail rapidly or result in large or catastrophic outflows. Steep valley topography and frequent eruptions at volcanoes in this region make for significant hazards associated with the formation and failure of volcanic debris dams. Published by Elsevier Science B.V.

Reduction of suspended solid and nutrient loss from agricultural lands by tailwater recovery systems

USDA-ARS?s Scientific Manuscript database

Best management practices are being implemented throughout the Lower Mississippi River Alluvial Valley with the aim of alleviating pressures placed on downstream aquatic systems by sediment and nutrient losses from agricultural land; however, research evaluating the performance of one practice, tail...

Patterns of differentiation among endangered pondberry populations

Treesearch

Craig S Echt; Dennis Deemer; Danny Gustafson

2011-01-01

Pondberry, Lindera melissifolia, is an endangered and partially clonally reproducing shrub species found in isolated populations that inhabit seasonally wet depressions in forested areas of the lower Mississippi River alluvial valley and southeastern regions of the United States. With eleven microsatellite loci, we quantified population genetic differentiation and...

Multilocus patterns of nucleotide polymorphism and demographic change in Taxodium distichum (Cupressaceae) in the lower Mississippi River alluvial valley

USGS Publications Warehouse

Kusumi, Junko; Zidong, Li; Kado, Tomoyuki; Tsumura, Yoshihiko; Middleton, Beth A.; Tachida, Hidenori

2010-01-01

Conclusions: Taxodium distichum had significantly higher nucleotide variation than C. japonica, and its patterns of polymorphism contrasted strikingly with those of the latter, which previously has been inferred to have experienced a reduction in population size.

A review of current and possible future human-water dynamics in Myanmar's river basins

NASA Astrophysics Data System (ADS)

Taft, Linda; Evers, Mariele

2016-12-01

Rivers provide a large number of ecosystem services and riparian people depend directly and indirectly on water availability and quality and quantity of the river waters. The country's economy and the people's well-being and income, particularly in agriculturally dominated countries, are strongly determined by the availability of sufficient water. This is particularly true for the country of Myanmar in South-east Asia, where more than 65 % of the population live in rural areas, working in the agricultural sector. Only a few studies exist on river basins in Myanmar at all and detailed knowledge providing the basis for human-water research is very limited. A deeper understanding of human-water system dynamics in the country is required because Myanmar's society, economy, ecosystems and water resources are facing major challenges due to political and economic reforms and massive and rapid investments from neighbouring countries. However, not only policy and economy modify the need for water. Climate variability and change are other essential drivers within human-water systems. Myanmar's climate is influenced by the Indian Monsoon circulation which is subject to interannual and also regional variability. Particularly the central dry zone and the Ayeyarwady delta are prone to extreme events such as serious drought periods and extreme floods. On the one hand, the farmers depend on the natural fertiliser brought by regular river inundations and high groundwater levels for irrigation; on the other hand, they suffer from these water-related extreme events. It is expected that theses climatic extreme events will likely increase in frequency and magnitude in the future as a result of global climate change. Different national and international interests in the abundant water resources may provide opportunities and risks at the same time for Myanmar. Several dam projects along the main courses of the rivers are currently in the planning phase. Dams will most likely modify the river flows, the sediment loads and also the still rich biodiversity in the river basins, to an unknown extent. Probably, these natural and anthropogenically induced developments will also impact a special type of farming; we call it alluvial farming in the river floodplains and on sandbars in the Ayeyarwady River basin in Myanmar, which is called Kaing and Kyun, respectively. Relevant aspects for future development of Myanmar's river basins combine environment-water-related factors, climate, economic and social development, water management and land use changes. Research on these interplays needs to capture the spatial and temporal dynamics of these drivers. However, it is only possible to gain a full understanding of all these complex interrelationships if multi-scale spatiotemporal information is analysed in an inter- and trans-disciplinary approach. This paper gives a structured overview of the current scientific knowledge available and reveals the relevance of this information with regard to human-environment and particularly to human-water interactions in Myanmar's river basins. By applying the eDPSIR framework, it identifies key indicators in the Myanmar human-water system, which has been shown to be exemplary by giving an example of use related to alluvial farming in the central dry zone.

What would happen if the Mississippi River changed its course to the Atchafalaya?

NASA Astrophysics Data System (ADS)

Xu, Y. J.

2017-12-01

The Mississippi River Delta faces an uncertain future as sea level keeps rising while the land continues to subside. In its latest Master Plan draft of 2017, the Louisiana Coastal Protection and Restoration Authority has outlined a $50 billion investment for 120 projects designed to build and maintain coastal Louisiana. These projects are all developed under the assumption that the Mississippi River (MR) would remain on its current course, which is artificially maintained through a control structure built in 1963 (also known as the Old River Control Structure, or ORCS) after it was realized that the river attempted to change its course back to its old river channel - the Atchafalaya River (AR). Since the ORCS is in operation of controlling only about 25% of the MR flow into the AR, little attention has been paid to the importance of possible riverbed changes downstream the avulsion node on the MR course switch. As one of the largest alluvial river in the world, the MR avulsed every 1,000-1,500 years in the past. Alluvial rivers avulse when two conditions are met: a sufficient in-channel aggradation and a major flood. In our ongoing study on sediment transport and channel morphology of the lower Mississippi River, we found that the first 30-mile reach downstream the ORCS has been experiencing rapid bed aggradation and channel narrowing in the past three decades. A mega flood could be a triggering point to overpower the man-made ORCS and allow the river abandon its current channel - the MR main stem. This is not a desirable path; however, nature has its own mechanism of choosing river flows, which do not bow to our expectation. The Missisippi River's flow is projected to increase in the future as global temperature continues to rise and hydrologic cycle intensifies. Additionally, rapid urbanization in the river basin will create conditions that foster the emergence of mega floods. It would be impractical to spend considerable resources for a river delta without assessing the future avulsion risk of the river upstream. My presentation will discuss the possibility of a Mississippi River avulsion, its consequences, as well as what assessment data we need to develop rational strategies.

Heat tracer test in an alluvial aquifer: Field experiment and inverse modelling

NASA Astrophysics Data System (ADS)

Klepikova, Maria; Wildemeersch, Samuel; Hermans, Thomas; Jamin, Pierre; Orban, Philippe; Nguyen, Frédéric; Brouyère, Serge; Dassargues, Alain

2016-09-01

Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in an injection well and monitoring the evolution of groundwater temperature and tracer concentration in the pumping well and in measurement intervals. To get insights in the 3D characteristics of the heat transport mechanisms, temperature data from a large number of observation wells closely spaced along three transects were used. Temperature breakthrough curves in observation wells are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume is explained by the groundwater flow gradient on the site and heterogeneities in the hydraulic conductivity field. Moreover, due to high injection temperatures during the field experiment a temperature-induced fluid density effect on heat transport occurred. By using a flow and heat transport numerical model with variable density coupled with a pilot point approach for inversion of the hydraulic conductivity field, the main preferential flow paths were delineated. The successful application of a field heat tracer test at this site suggests that heat tracer tests is a promising approach to image hydraulic conductivity field. This methodology could be applied in aquifer thermal energy storage (ATES) projects for assessing future efficiency that is strongly linked to the hydraulic conductivity variability in the considered aquifer.

Thickness of the Mississippi River Valley confining unit, eastern Arkansas

USGS Publications Warehouse

Gonthier, Gerard; Mahon, Gary L.

1993-01-01

Concern arose in the late 1980s over the vulnerability of the Mississippi Valley alluvial aquifer to contamination from potential surface sources related to pesticide or fertilizer use, industrial activity, landfills, or livestock operations. In 1990 a study was begun to locate areas in Arkansas where the groundwater flow system is susceptible to contamination by surface contaminants. As a part of that effort, the thickness of the clay confining unit overlying the alluvial aquifer in eastern Arkansas was mapped. The study area included all or parts of 27 counties in eastern Arkansas that are underlain by the alluvial aquifer and its overlying confining unit. A database of well attributes was compiled based on data from driller's logs and from published data and stored in computer files. A confining-unit thickness map was created from the driller's-log database using geographic information systems technology. A computer program was then used to contour the data. Where the confining unit is present, it ranges in thickness from 0 feet in many locations in the study area to 140 feet in northeastern Greene County and can vary substantially over short distances. Although general trends in the thickness of the confining unit are apparent, the thickness has great spatial variability. An apparent relation exists between thickness of the confining unit and spatial variability in thickness. In areas where the thickness of the confining unit is 40 feet or less, such as in Clay, eastern Craighead, northwestern Mississippi, and Woodruff Counties, thickness of the unit tends robe more uniform than in areas where the thickness of the unit generally exceeds 40 feet, such as in Arkansas, Lonoke, and Prairie Counties. At some sites the confining unit is very thick compared to its thickness in the immediate surrounding area. Locations of abandoned Mississippi River meander channels generally coincide with location of locally thick confining unit. Deposition of the confining unit onto the coarser alluvial aquifer deposits has reduced the relief of the land surface. Hence, the altitude of the top of the alluvial aquifer varies more than the altitude of the land surface and is indicative of a depositional setting.

Terrestrial Evidence for Holocene Pluvials in Coastal Southern California

NASA Astrophysics Data System (ADS)

Reynolds, L.; Simms, A.; Rockwell, T. K.; Peters, R. B.

2016-12-01

In 1861 a series of large storms attributed to a prolonged atmospheric river event impacted the coast of California, inundated large regions of the state for weeks on end, stalled the government, and devastated the economy. A recent report by the USGS, the Arkstorm Report, predicted a similar sized event today could cost the state more than $700 billion in long-term economic losses. The high-resolution sedimentary record from the Santa Barbara Basin indicates 8 flooding events similar to or larger than the 1861 event have occurred in the past 2000 years. However, little terrestrial evidence for these events has been identified to determine coastal impacts or test the completeness of the Santa Barbara Channel record. Here we show evidence from coastal wetlands along the Santa Barbara Channel that alluvial fan progradation events have recurred at least 7 times over the last 7ka. Because most streams in the Transverse ranges flow only during storms, these alluvial fan building events are interpreted to represent large flooding events. We use a chronology derived from over 40 radiocarbon dates from 39 vibracores up to 4m in length, and 7 Geoprobe cores up to 13m in length from Carpinteria Marsh to test whether these alluvial fan progradation events and/or other abrupt stratigraphic changes are synchronous with regionally documented climatic events. We show that a compilation of biological, sedimentological, geochemical, and archeological proxies for flooding, storms, and/or wet climate conditions from sites throughout the southwestern United States demonstrates the difficulty in correlating and interpreting regional Holocene events across variable proxies and geographic regions. Despite this variation, isolating the purely sedimentological proxies (increase in sedimentation rates, increase in grain size, decrease in organic content, etc.) seems to demonstrate a correlation between alluvial fan progradation events in Carpinteria at 0.3-0.9 ka and 3.5 ka and records of wet conditions throughout the western US, while a lack of alluvial fan deposits from 2-3 ka correlates with the Late Holocene Dry Period. Whether these flooding events represent increased occurrences of atmospheric river events, heightened El Nino activity, or longer-term changes in atmospheric conditions remains an open question.

Streambed infiltration and ground-water flow from the trout creek drainage, an intermittent tributary to the Humboldt River, north-central Nevada: Chapter K in Ground-water recharge in the arid and semiarid southwestern United States (Professional Paper 1703)

USGS Publications Warehouse

Prudic, David E.; Niswonger, Richard G.; Harrill, James R.; Wood, James L.; Stonestrom, David A.; Constantz, Jim; Ferré, Ty P.A.; Leake, Stanley A.

2007-01-01

Ground water is abundant in many alluvial basins of the Basin and Range Physiographic Province of the western United States. Water enters these basins by infiltration along intermittent and ephemeral channels, which originate in the mountainous regions before crossing alluvial fans and piedmont alluvial plains. Water also enters the basins as subsurface ground-water flow directly from the mountains, where infiltrated precipitation recharges water-bearing rocks and sediments at these higher elevations. Trout Creek, a typical intermittent stream in the Middle Humboldt River Basin in north-central Nevada, was chosen to develop methods of estimating and characterizing streambed infiltration and ground-water recharge in mountainous terrains. Trout Creek has a drainage area of about 4.8 × 107 square meters. Stream gradients range from more than 1 × 10–1 meter per meter in the mountains to 5 × 10–3 meter per meter at the foot of the piedmont alluvial plain. Trout Creek is perennial in short reaches upstream of a northeast-southwest trending normal fault, where perennial springs discharge to the channel. Downstream from the fault, the water table drops below the base of the channel and the stream becomes intermittent.Snowmelt generates streamflow during March and April, when streamflow extends onto the piedmont alluvial plain for several weeks in most years. Rates of streambed infiltration become highest in the lowest reaches, at the foot of the piedmont alluvial plain. The marked increases in infiltration are attributed to increases in streambed permeability together with decreases in channel-bed armoring, the latter which increases the effective area of the channel. Large quartzite cobbles cover the streambed in the upper reaches of the stream and are absent in the lowest reach. Such changes in channel deposits are common where alluvial fans join piedmont alluvial plains. Poorly sorted coarse and fine sediments are deposited near the head of the fan, while finer-grained but better sorted gravels and sands are deposited near the foot.All flow in Trout Creek is lost to infiltration in the upper and middle reaches of the channel during years of normal to below-normal precipitation. During years of above-normal precipitation, streamflow extends beyond the piedmont alluvial plain to the lower reaches of the channel, where high rates of infiltration result in rapid stream loss. The frequency and duration of streambed infiltration is sufficient to maintain high water contents and low chloride concentrations, compared with interchannel areas, to depths of at least 6 m beneath the channel. Streamflow, streambed infiltration, and unsaturated-zone thickness are all highly variable along intermittent streams, resulting in recharge that is highly variable as well.Average annual ground-water recharge in the mountainous part of the Trout Creek drainage upstream of Marigold Mine was estimated on the basis of chloride balance to be 5.2 × 105 cubic meters. Combined with an average annual surface runoff exiting the mountains of 3.4 × 105cubic meters, the total annual volume of inflow to alluvial-basin sediments from the mountainous part of the Trout Creek is 8.6 × 105 cubic meters, assuming that all runoff infiltrates the stream channel. This equates to about 7 percent of average annual precipitation, which is about the same percentage estimated for ground-water recharge using the original Maxey-Eakin method.

Altered hydrologic and geomorphic processes and bottomland hardwood plant communities of the lower White River Basin

USGS Publications Warehouse

King, Sammy L.; Keim, Richard F.; Hupp, Cliff R.; Edwards, Brandon L.; Kroschel, Whitney A.; Johnson, Erin L.; Cochran, J. Wesley

2016-09-12

Determine stand establishment patterns of bottomland hardwoods within selected plant communities along three sections of the floodplain. This study provides baseline information on the current geomorphic and hydrologic conditions of the river and can assist in the interpretation of forest responses to past hydrologic and geomorphic processes. Understanding the implications for floodplain forests of geomorphic adjustment in the Lower Mississippi Alluvial Valley is key to managing the region’s valuable resources for a sustainable future.

Environmental Impact Study of the Northern Section of the Upper Mississippi River. Pool 7.

DTIC Science & Technology

1973-11-01

7945 Salix interior Rowlee 7911 Salix rig a luhi. 7913 Ulm-us americana L. 7922,7955 SHRUBS Cephalanthus occidentalis L. 7924,7952 VINES Cuscuta p. 7916...still, I believe, a very useful indicator. Tables A16, Al7 andAl8 give frequency values for alluvial forest shrubs , vines , and herbs respectively...intcnsively utilized to meet the trans- protation needs of the Midwest . 33 Long before the coming of the first white settlers, the Mississippi River

Cultural Resources Survey of Mile 306.3 to 293.4-R on the Mississippi River, Concordia, Pointe Coupee and West Feliciana Parishes, Louisiana

DTIC Science & Technology

1993-01-01

from Cairo, Illinois to an arbitrary location upstream of the Gulf of Mexico where the delta plain originates . Specifically, the proposed project area...dominated by sediment of Mississippi River alluvial origin . In the northern part of Pointe Coupee Parish, the sediment deposited by the Red or Arkansas...North America. Domesticated cultigens, pottery making, and mound building are recognized as characteristics that suggest increased populations, social

MX: Milestone II. Final Environmental Impact Statement. Volume 6. Public Comments

DTIC Science & Technology

1978-10-06

bottom of the San Antonio Valley are river channel and alluvial deposits c. , , of Holocene age, underlain by the Paso Robles Formation and Careaga...outlined aros contain approx. 8,000 sq. miles. This is the estimated White Sands missile Rang. :as-78,500except for Kies. River proper, land It * -? mainly...deleterious impact of this new demand on the standard of living of low and fixed income >-14 individuals. The bulk of the demand for employment will be

Geologic map of the Fort Morgan 7.5' quadrangle, Morgan County, Colorado

USGS Publications Warehouse

Berry, Margaret E.; Taylor, Emily M.; Slate, Janet L.; Paces, James B.; Hanson, Paul R.; Brandt, Theodore R.

2018-06-08

The Fort Morgan 7.5′ quadrangle is located on the semiarid plains of northeastern Colorado, along the South Platte River corridor where the river has incised into Upper Cretaceous Pierre Shale. The Pierre Shale is largely covered by surficial deposits that formed from alluvial, eolian, and hillslope processes operating in concert with environmental changes from the late Pliocene to the present. The South Platte River, originating high in the Colorado Rocky Mountains, has played a major role in shaping surficial geology in the map area, which is several tens of kilometers downstream from where headwater tributaries join the river. Recurrent glaciation (and deglaciation) of basin headwaters has affected river discharge and sediment supply far downstream, influencing deposition of alluvium and river incision in the Fort Morgan quadrangle. Distribution and characteristics of the alluvial deposits indicate that during the Pleistocene the course of the river within the map area shifted progressively southward as it incised, and by late middle Pleistocene the river was south of its present position, cutting and filling a deep paleochannel near the south edge of the quadrangle. The river shifted back to the north during the late Pleistocene. Kiowa and Bijou Creeks are unglaciated tributaries originating in the Colorado Piedmont east of the Front Range that also have played a major role in shaping surficial geology of the map area. Periodically during the late Pleistocene, major flood events on these tributaries deposited large volumes of sediment at and near their confluences, forming a broad, low-gradient fan composed of sidestream alluvium that could have occasionally dammed the river for short periods of time. Wildcat Creek, also originating on the Colorado Piedmont, and the small drainage of Cris Lee Draw dissect the map area north of the river. Eolian sand deposits of the Sterling (north of river) and Fort Morgan (south of river) dune fields cover much of the quadrangle and record past episodes of sand mobilization during times of prolonged drought. With the onset of irrigation and damming during historical times, the South Platte River has changed from a broad, shallow, and sandy braided river with highly variable seasonal discharge to a much narrower, deeper river with braided-meandering transition morphology and more uniform discharge.

Mapping groundwater renewability using age data in the Baiyang alluvial fan, NW China

NASA Astrophysics Data System (ADS)

Huang, Tianming; Pang, Zhonghe; Li, Jie; Xiang, Yong; Zhao, Zhijiang

2017-05-01

Groundwater age has been used to map renewability of water resources within four groups: strong, partial, and rare renewability, and non-renewable. The Baiyang alluvial fan in NW China is a representative area for examining groundwater recharge from river infiltration and for mapping groundwater renewability, and it has been investigated using multiple isotopes and water chemistry. Systematic sampling included 52 samples for 2H and 18O analysis and 32 samples for 3H, 13C and 14C analysis. The δ13C compositions remain nearly constant throughout the basin (median -12.7‰) and indicate that carbonate dissolution does not alter 14C age. The initial 14C activity of 80 pmC, obtained by plotting 3H and 14C activity, was used to correct groundwater 14C age. The results show that areas closer to the river consist of younger groundwater ages; this suggests that river infiltration is the main recharge source to the shallow groundwater system. However, at distances far away from the river, groundwater ages become older, i.e., from modern water (less than 60 year) to pre-modern water (from 60 to 1,000 years) and paleowater (more than 1,000 yeas). The four classifications of groundwater renewability have been associated with different age ranges. The area of shallow groundwater with strong renewability accounts for 74% of the total study area. Because recharge condition (river infiltration) controls overall renewability, a groundwater renewability map is of significant importance to the management of groundwater exploitation of this area as well as other arid groundwater basins.

Water chemistry near the closed Norman Landfill, Cleveland County, Oklahoma 1995

USGS Publications Warehouse

Schlottmann, Jamie L.

2001-01-01

The Norman Landfill was selected for study as part of the U.S. Geological Survey Toxic Substances Hydrology Program in 1994. The landfill is located south of the City of Norman on alluvial deposits of the Canadian River. Type of waste deposited in the landfill from 1922 to 1973 was largely unrestricted and may include substances now recognized as hazardous. Dissolved and suspended substances leached from wastes in the closed and capped landfill are now in ground water extending toward the Canadian River as a plume of leachate. Water samples were collected from two stock wells, one domestic well, temporary drive-point wells, the Canadian River, and a small intermittent stream hydraulically downgradient of the capped landfill known as the slough. Most constituent concentrations were greater in ground water downgradient from the capped landfill than in background ground water and were greater in the slough than in the Canadian River. Concentrations of most constituents in the Canadian River, other than sulfate, manganese, and iron, were similar to concentrations in background ground water. Some constituents measured in ground-water for this investigation are potential indicators of leachate contamination. Potential indicators that could be used to differentiate leachate contaminated water from uncontaminated ground water of the alluvial aquifer include specific conductance, chloride, alkalinity, dissolved organic carbon, boron, and dD. Specific conductance and chloride were greater in water from wells downgradient of the landfill than water from background wells. Dissolved organic carbon and boron also were greater in the leachate contaminated ground water than in background ground water.

Deep Time Ecosystem Engineers: The Correlation between Palaeozoic Vegetation, Evolution of Physical Riverine Habitats, and Plant and Animal Terrestrialization

NASA Astrophysics Data System (ADS)

Davies, N. S.; Gibling, M. R.

2012-04-01

Evidence from the deep time geological record attests to the fundamental importance of plant life to the construction of physical habitats within fluvial environments. Data from an extensive literature review and original fieldwork has demonstrated that many landforms and geomorphic features present in modern river systems do not appear in the deep time stratigraphic record until terrestrial vegetation had adopted certain evolutionary advances that enabled them: for example, stable point bars are associated with the development of deep rooting in the Siluro-Devonian and avulsive anabranching fluvial systems appear at the same time as extensive arborescent vegetation in the Carboniferous. In this presentation, we demonstrate a correlation between the diversification of physical fluvial sedimentary environments and the expansion of terrestrial fauna and flora throughout the Cambrian to Carboniferous, and offer an explanation for this observation that considers plants as ecosystem engineers on an evolutionary timescale. Many extrinsic factors have been considered when attempting to identify controls on the evolutionary timelines of terrestrialization for various different organisms. Factors such as O2 and CO2 levels in the atmosphere, climatic events, global tectonic organisation, sea-level changes, extinction events, weathering rates and nutrient supply are all known to have played a role. However, another factor is likely to have been a fundamental prerequisite for achieving terrestrial biodiversity: the variety of physical habitats available for newly evolved organisms. In fluvial environments, this is a function of the diversity of hydrodynamic regimes (both temporal and spatial) within the world's river systems. In a world where only sheet-like ephemeral braided rivers existed, such as appears to be the case in pre-vegetation settings, both the geographic extent of riparian margins and the diversity of hydrodynamic regimes would be minimal. However, as fluvial corridors narrowed throughout the Ordovician and Silurian, the potential importance of riparian zones as a global biome would have increased as they became more extensive in continental environments. Furthermore, the move towards climatic controls on the ephemeral or perennial nature of streams would have boosted the diversity of temporally diverse hydrodynamic regimes. As single-thread meandering channels and extensive muddy floodplains, stabilised by vegetation, became significant components of the global suite of alluvial geomorphic components throughout the Siluro-Devonian, further diversification of the extent and diversity of physical habitats within the global riparian biome occurred. Into the Carboniferous, the evolution of the anabranching habit within alluvial systems created further new physical landforms for colonization and would have promoted increasingly complex hyporheic flow regimes. Furthermore the associated advent of arborescent vegetation and, specifically, the large woody debris supplied by this, would have created a wealth of new microhabitats for continental organisms. The expanding extent and diversity of physical alluvial niches during the Palaeozoic can be argued to be an underappreciated driver of the terrestrialization of early continental life. The study of the deep time fossil and stratigraphic record also illustrates that vegetation is a fundamental prerequisite for the creation of biogeomorphic alluvial landforms and physical habitats and microhabitats.

Spatially dependent responses of a large-river fish assemblage to bank stabilization and side channels

USGS Publications Warehouse

Reinhold, Ann Marie; Bramblett, Robert G.; Zale, Alexander V.; Poole, Geoffrey C.; Roberts, David W.

2017-01-01

The alteration of rivers by anthropogenic bank stabilization to prevent the erosion of economically valuable lands and structures has become commonplace. However, such alteration has ambiguous consequences for fish assemblages, especially in large rivers. Because most large, temperate rivers have impoundments, it can be difficult to separate the influences of bank stabilization structures from those of main-stem impoundments, especially because both stabilization structures and impoundments can cause side-channel loss. Few large rivers are free flowing and retain extensive side channels, but the Yellowstone River (our study area) is one such river. We hypothesized that in this river (1) bank stabilization has changed fish assemblage structure by altering habitats, (2) side-channel availability has influenced fish assemblage structure by providing habitat heterogeneity, and (3) the influences of bank stabilization and side channels on fish assemblages were spatially scale dependent. We developed a spatially explicit framework to test these hypotheses. Fish assemblage structure varied with the extent of bank stabilization and the availability of side channels; however, not all assemblage subsets were influenced. Nevertheless, bank stabilization and side channels had different and sometimes opposite influences on the fish assemblage. The effects of side channels on fish were more consistent and widespread than those of bank stabilization; the catches of more fishes were positively correlated with side-channel availability than with the extent of bank stabilization. The influences of bank stabilization and side channels on the relative abundances of fish also varied, depending on species and river bend geomorphology. The variation in river morphology probably contributed to the assemblage differences between stabilized and reference river bends; stabilized alluvial pools were deeper than reference alluvial pools, but the depths of stabilized and reference bluff pools did not differ. The strengths of the relationships among fish assemblages, bank stabilization, and side channels were spatially scale dependent; optimum spatial scales ranged from less than 200 m to 3,200 m up- and downstream, suggesting that bank stabilization and side channels influenced fish assemblages across multiple spatial scales.

Improved simulation of river water and groundwater exchange in an alluvial plain using the SWAT model

USDA-ARS?s Scientific Manuscript database

Hydrological interaction between surface and subsurface water systems has a significant impact on water quality, ecosystems and biogeochemistry cycling of both systems. Distributed models have been developed to simulate this function, but they require detailed spatial inputs and extensive computati...

Stewardship of water and fertilizer in irrigated cotton

USDA-ARS?s Scientific Manuscript database

Agriculture is a vital part of the southeast Missouri economy and it is essential that we maintain our precious soil and water resources. While we have shallow, high quality groundwater for irrigation, it is important to realize that our aquifer, the Mississippi River Valley Alluvial Aquifer, also p...

Boundary shear stress along rigid trapezoidal bends

Treesearch

Christopher I. Thornton; Kyung-Seop Sin; Paul Sclafani; Steven R. Abt

2012-01-01

The migration of alluvial channels through the geologic landform is an outcome of the natural erosive processes. Mankind continually attempts to stabilize channel meandering processes, both vertically and horizontally, to reduce sediment discharge, provide boundary definition, and enable economic development along the river's edge. A critical component in the...

Dynamic transport capacity in gravel-bed river systems

Treesearch

T. E. Lisle; B. Smith

2003-01-01

Abstract - Sediment transport capacity mediates the transfer and storage of bed material between alluvial reservoirs in a drainage system. At intermediate time scales corresponding to the evolution of sediment pulses, conditions governing bed-material transport capacity under the hydrologic regime respond to variations in storage and sediment flux as pulses extend,...

Survival and growth of 31 Populus clones in South Carolina

Treesearch

David R. Coyle; Mark D. Coleman; Jaclin A. Durant; Lee A. Newman

2006-01-01

Populus species and hybrids have many practical applications, but clonal performance is relatively undocumented in the southeastern United States outside of the Mississippi River alluvial floodplain. In spring 2001, 31 Populus clones were planted on two sites in South Carolina, USA. The sandy, upland site received irrigation and...

Environmental impacts on the hydrology of ephemeral streams and alluvial aquifers

NASA Astrophysics Data System (ADS)

Kuells, C.; Marx, V.; Bittner, A.; Ellmies, R.; Seely, M.

2009-04-01

In arid and semi-arid regions alluvial groundwater resources of ephemeral streams are highly important for water supplies and ecosystems. Recent projects have studied processes of indirect recharge in situ and in detail (Dahan et al., 2008; Klaus et al., 2008). Still, little is known about the vulnerability of these aquifers to environmental impacts like surface dam constructions, land-use changes and climatic conditions as well as the time and type of response to such external impacts. With a catchment size of about 30.000 km² the Swakop River in Namibia is the largest of the country's twelve major ephemeral streams draining westwards into the Atlantic Ocean. The alluvial groundwater resources have been affected by the construction of two major surface water dams in the upper catchment as well as by abstractions for rural water supply, farming and mining downstream of the constructed dams (referred to as lower catchment). The determination of environmental impacts in the Swakop River catchment is difficult due to scarce hydrometric and water quality data. In order to obtain a better understanding of the hydrological system under changing environmental conditions a spatially distributed environmental tracer approach was applied. A longitudinal profile of groundwater samples was taken within a field study along the alluvial aquifer of the Swakop River. The samples were analysed for stable isotopes (18O, 2H), major ions and trace elements as well as for the residence time indicators CFC and SF6. The combined application of groundwater residence time analysis, stable isotope measurements and hydrochemical characterisation was used in order to associate a time scale with groundwater quality data. This method provides dated information on recharge and water quality before and after dam construction and can be used to detect environmental impacts on the hydrological system. CFC-12 analysis resulted in recharge years ranging from 1950 (0.01 pmol/l) to 1992 (1.4 pmol/l). Seven of 14 groundwater samples represent mainly groundwater recharged before or between the construction of surface water dams (1970 and 1978), the remaining samples represent groundwater recharge after dam construction. The groundwater residence time is generally short (recharge mainly after 1980) in the upper catchment and much higher (recharge mainly before 1980 and before dam construction) in the lower part of the catchment. Combining the age and isotope information shows how the surface water dams modified the pattern of groundwater recharge. The lower catchment has been partly cut off from the upper part in terms of indirect groundwater recharge by floods which means that most large floods originating in the headwaters of the Swakop River do not reach the lower alluvial aquifer anymore. The relationship between groundwater age and groundwater constituents helped to define baselines of hydrological properties (origin of water, recharge altitude) and of hydrochemical composition prior to the construction of dams (and other anthropogenic impacts). The well defined relationship between groundwater age and altitude of the river further helps to assess how fast different segments will be affected by these environmental impacts. References Dahan, O., Tatarsky, B., Enzel, Y., Kuells, C., Seely, M., Benito, G. (2008) Dynamics of Flood Water Infiltration and Ground Water Recharge in Hyperarid Desert. Ground Water, Vol. 46, 3. (6-2008), pp. 450-461. Klaus, J., Kuells, C., Dahan, O. (2008): Evaluating the recharge mechanism of the Lower Kuiseb Dune Area using mixing cell modeling and residence time data. Journal of Hydrology, v. 358, p. 304-316.

Physical context for theoretical approaches to sediment transport magnitude-frequency analysis in alluvial channels

NASA Astrophysics Data System (ADS)

Sholtes, Joel; Werbylo, Kevin; Bledsoe, Brian

2014-10-01

Theoretical approaches to magnitude-frequency analysis (MFA) of sediment transport in channels couple continuous flow probability density functions (PDFs) with power law flow-sediment transport relations (rating curves) to produce closed-form equations relating MFA metrics such as the effective discharge, Qeff, and fraction of sediment transported by discharges greater than Qeff, f+, to statistical moments of the flow PDF and rating curve parameters. These approaches have proven useful in understanding the theoretical drivers behind the magnitude and frequency of sediment transport. However, some of their basic assumptions and findings may not apply to natural rivers and streams with more complex flow-sediment transport relationships or management and design scenarios, which have finite time horizons. We use simple numerical experiments to test the validity of theoretical MFA approaches in predicting the magnitude and frequency of sediment transport. Median values of Qeff and f+ generated from repeated, synthetic, finite flow series diverge from those produced with theoretical approaches using the same underlying flow PDF. The closed-form relation for f+ is a monotonically increasing function of flow variance. However, using finite flow series, we find that f+ increases with flow variance to a threshold that increases with flow record length. By introducing a sediment entrainment threshold, we present a physical mechanism for the observed diverging relationship between Qeff and flow variance in fine and coarse-bed channels. Our work shows that through complex and threshold-driven relationships sediment transport mode, channel morphology, flow variance, and flow record length all interact to influence estimates of what flow frequencies are most responsible for transporting sediment in alluvial channels.

Laminar laboratory rivers

NASA Astrophysics Data System (ADS)

Seizilles, Grégoire; Devauchelle, Olivier; Lajeunesse, Éric; Métivier, François

2014-05-01

A viscous fluid flowing over fine plastic grains spontaneously channelizes into a few centimeters-wide river. After reaching its equilibrium shape, this stable laboratory flume is able to carry a steady load of sediments, like many alluvial rivers. When the sediment discharge vanishes, the river size, shape and slope fit the threshold theory proposed by Glover and Florey (1951), which assumes that the Shields parameter is critical on the channel bed. As the sediment discharge is increased, the river widens and flattens. Surprisingly, the aspect ratio of its cross section depends on the sediment discharge only, regardless of the water discharge. We propose a theoretical interpretation of these findings based on the balance between gravity, which pulls particles towards the center of the channel, and the diffusion of bedload particles, which pushes them away from areas of intense bedload.

Simulation of water-use conservation scenarios for the Mississippi Delta using an existing regional groundwater flow model

USGS Publications Warehouse

Barlow, Jeannie R.B.; Clark, Brian R.

2011-01-01

The Mississippi River alluvial plain in northwestern Mississippi (referred to as the Delta), once a floodplain to the Mississippi River covered with hardwoods and marshland, is now a highly productive agricultural region of large economic importance to Mississippi. Water for irrigation is supplied primarily by the Mississippi River Valley alluvial aquifer, and although the alluvial aquifer has a large reserve, there is evidence that the current rate of water use from the alluvial aquifer is not sustainable. Using an existing regional groundwater flow model, conservation scenarios were developed for the alluvial aquifer underlying the Delta region in northwestern Mississippi to assess where the implementation of water-use conservation efforts would have the greatest effect on future water availability-either uniformly throughout the Delta, or focused on a cone of depression in the alluvial aquifer underlying the central part of the Delta. Five scenarios were simulated with the Mississippi Embayment Regional Aquifer Study groundwater flow model: (1) a base scenario in which water use remained constant at 2007 rates throughout the entire simulation; (2) a 5-percent 'Delta-wide' conservation scenario in which water use across the Delta was decreased by 5 percent; (3) a 5-percent 'cone-equivalent' conservation scenario in which water use within the area of the cone of depression was decreased by 11 percent (a volume equivalent to the 5-percent Delta-wide conservation scenario); (4) a 25-percent Delta-wide conservation scenario in which water use across the Delta was decreased by 25 percent; and (5) a 25-percent cone-equivalent conservation scenario in which water use within the area of the cone of depression was decreased by 55 percent (a volume equivalent to the 25-percent Delta-wide conservation scenario). The Delta-wide scenarios result in greater average water-level improvements (relative to the base scenario) for the entire Delta area than the cone-equivalent scenarios; however, the cone-equivalent scenarios result in greater average water-level improvements within the area of the cone of depression because of focused conservation efforts within that area. Regardless of where conservation is located, the greatest average improvements in water level occur within the area of the cone of depression because of the corresponding large area of unsaturated aquifer material within the area of the cone of depression and the hydraulic gradient, which slopes from the periphery of the Delta towards the area of the cone of depression. Of the four conservation scenarios, the 25-percent cone-equivalent scenario resulted in the greatest increase in storage relative to the base scenario with a 32-percent improvement over the base scenario across the entire Delta and a 60-percent improvement within the area of the cone of depression. Overall, the results indicate that focusing conservation efforts within the area of the cone of depression, rather than distributing conservation efforts uniformly across the Delta, results in greater improvements in the amount of storage within the alluvial aquifer. Additionally, as the total amount of conservation increases (that is, from 5 to 25 percent), the difference in storage improvement between the Delta-wide and cone-equivalent scenarios also increases, resulting in greater gains in storage in the cone-equivalent scenario than in the Delta-wide scenario for the same amount of conservation.

Colonizing Dynamic Alluvial and Coastal Landscapes in the Holocene

NASA Astrophysics Data System (ADS)

Kidder, T.; Liu, X.; Ervin, K.

2017-12-01

Throughout the Holocene humans have had to adapt to dynamic, rapidly changing alluvial and coastal landscapes. Understanding when people inhabit a given environment is an important starting point for exploring human adaptations, but increasingly we need to consider how, and especially why certain environments are used—or not used— so we can understand the consequences of these human actions. Using four case studies—one from the Yellow River Valley, China, one from coastal Jiangsu, China, one from the Mississippi River Valley (Mississippi, USA) and one from the Mississippi River delta (Louisiana , USA)—we develop a model of how humans at various stages of cultural development colonize new environments. Using archaeological data and ecological modeling we investigate the relationship between the timing of landscape colonization and the ecological richness and predictability of any given environment. As new landscapes emerge and mature humans adopt different strategies for exploiting these novel environments that begins with episodic use and increasingly shifts to stable, long-term habitation. The early phase of landscape colonization appears to be the most significant period because it shapes human environmental practices and sets each culture on a trajectory of socio-cultural development. Thus, human-environment interaction is a critical part of the emergence of cultural patterns that shapes the past, present, and even the future.

Groundwater quality assessment and pollution source apportionment in an intensely exploited region of northern China.

PubMed

Zhang, Qianqian; Wang, Huiwei; Wang, Yanchao; Yang, Mingnan; Zhu, Liang

2017-07-01

Deterioration in groundwater quality has attracted wide social interest in China. In this study, groundwater quality was monitored during December 2014 at 115 sites in the Hutuo River alluvial-pluvial fan region of northern China. Results showed that 21.7% of NO 3 - and 51.3% of total hardness samples exceeded grade III of the national quality standards for Chinese groundwater. In addition, results of gray relationship analysis (GRA) show that 64.3, 10.4, 21.7, and 3.6% of samples were within the I, II, IV, and V grades of groundwater in the Hutuo River region, respectively. The poor water quality in the study region is due to intense anthropogenic activities as well as aquifer vulnerability to contamination. Results of principal component analysis (PCA) revealed three major factors: (1) domestic wastewater and agricultural runoff pollution (anthropogenic activities), (2) water-rock interactions (natural processes), and (3) industrial wastewater pollution (anthropogenic activities). Using PCA and absolute principal component scores-multivariate linear regression (APCS-MLR), results show that domestic wastewater and agricultural runoff are the main sources of groundwater pollution in the Hutuo River alluvial-pluvial fan area. Thus, the most appropriate methods to prevent groundwater quality degradation are to improve capacities for wastewater treatment and to optimize fertilization strategies.

Using oblique digital photography for alluvial sandbar monitoring and low-cost change detection

USGS Publications Warehouse

Tusso, Robert B.; Buscombe, Daniel D.; Grams, Paul E.

2015-01-01

The maintenance of alluvial sandbars is a longstanding management interest along the Colorado River in Grand Canyon. Resource managers are interested in both the long-term trend in sandbar condition and the short-term response to management actions, such as intentional controlled floods released from Glen Canyon Dam. Long-term monitoring is accomplished at a range of scales, by a combination of annual topographic survey at selected sites, daily collection of images from those sites using novel, autonomously operating, digital camera systems (hereafter referred to as 'remote cameras'), and quadrennial remote sensing of sandbars canyonwide. In this paper, we present results from the remote camera images for daily changes in sandbar topography.

Hyporheic Zone Residence Time Distributions in Regulated River Corridors

NASA Astrophysics Data System (ADS)

Song, X.; Chen, X.; Shuai, P.; Gomez-Velez, J. D.; Ren, H.; Hammond, G. E.

2017-12-01

Regulated rivers exhibit stage fluctuations at multiple frequencies due to both natural processes (e.g., seasonal cycle) and anthropogenic activities (e.g., dam operation). The interaction between the dynamic river flow conditions and the heterogeneous aquifer properties results in complex hydrologic exchange pathways that are ubiquitous in free-flowing and regulated river corridors. The dynamic nature of the exchange flow is reflected in the residence time distribution (RTD) of river water within the groundwater system, which is a key metric that links river corridor biogeochemical processes with the hydrologic exchange. Understanding the dynamics of RTDs is critical to gain the mechanistic understanding of hydrologic exchange fluxes and propose new parsimonious models for river corridors, yet it is understudied primarily due to the high computational demands. In this study, we developed parallel particle tracking algorithms to reveal how river flow variations affect the RTD of river water in the alluvial aquifer. Particle tracking was conducted using the velocity outputs generated by three-dimensional groundwater flow simulations of PFLOTRAN in a 1600 x 800 x 20m model domain within the DOE Hanford Site. Long-term monitoring data of inland well water levels and river stage were used for eight years of flow simulation. Nearly a half million particles were continually released along the river boundary to calculate the RTDs. Spectral analysis of the river stage data revealed high-frequency (sub-daily to weekly) river stage fluctuations caused by dam operations. The higher frequencies of stage variation were progressively filtered to generate multiple sets of flow boundary conditions. A series of flow simulations were performed by using the filtered flow boundary conditions and various degrees of subsurface heterogeneity to study the relative contribution of flow dynamics and physical heterogeneity on river water RTD. Our results revealed multimodal RTDs of river water as a result of the highly variable exchange pathways driven by interactions between dynamic flow and aquifer heterogeneity. A relationship between the RTD and frequency of flow variation was built for each heterogeneity structure, which can be used to assess the potential ecological consequences of dam operations in regulated rivers.

Earth Observations taken by the Expedition 13 crew

NASA Image and Video Library

2006-09-04

ISS013-E-76262 (4 Sept. 2006) --- Lake Morari, Tibet is featured in this image photographed by an Expedition 13 crewmember onboard the International Space Station. Melt-water from glaciers to the east and west drains into Lake Morari, a large lake on the Tibetan Plateau which lies at an altitude of 4,521 meters (14,830 feet). The main inflow to the lake is via a west-side stream. Mud from this river gives the light blue hues to the lake water. The well-formed alluvial fan (center), built by sediment from the main inflow river, is the reason the lake has formed at this point in the valley. The fan has dammed up the depression now occupied by Lake Morari (approximately 7 kilometers wide in this view) and forms the curved southern shore of the lake. The apex of the fan lies fully 40 meters above the level of the lake. The change of color and texture on the fan seems to result from a new influx of gray sediment on top of an older fan which had several channels cut into it. Interestingly, the alluvial fan also acts as the only outlet of the lake, although no obvious outlet channel can be seen in this detailed view. South of the fan an outlet river appears as a green surface, possibly due to aquatic vegetation or algae. Altitude measurements show that the outlet river lies many meters below the lake surface.

The effect of increasing salinity and forest mortality on soil nitrogen and phosphorus mineralization in tidal freshwater forested wetlands

USGS Publications Warehouse

Noe, Gregory B.; Krauss, Ken W.; Lockaby, B. Graeme; Conner, William H.; Hupp, Cliff R.

2013-01-01

Tidal freshwater wetlands are sensitive to sea level rise and increased salinity, although little information is known about the impact of salinification on nutrient biogeochemistry in tidal freshwater forested wetlands. We quantified soil nitrogen (N) and phosphorus (P) mineralization using seasonal in situ incubations of modified resin cores along spatial gradients of chronic salinification (from continuously freshwater tidal forest to salt impacted tidal forest to oligohaline marsh) and in hummocks and hollows of the continuously freshwater tidal forest along the blackwater Waccamaw River and alluvial Savannah River. Salinification increased rates of net N and P mineralization fluxes and turnover in tidal freshwater forested wetland soils, most likely through tree stress and senescence (for N) and conversion to oligohaline marsh (for P). Stimulation of N and P mineralization by chronic salinification was apparently unrelated to inputs of sulfate (for N and P) or direct effects of increased soil conductivity (for N). In addition, the tidal wetland soils of the alluvial river mineralized more P relative to N than the blackwater river. Finally, hummocks had much greater nitrification fluxes than hollows at the continuously freshwater tidal forested wetland sites. These findings add to knowledge of the responses of tidal freshwater ecosystems to sea level rise and salinification that is necessary to predict the consequences of state changes in coastal ecosystem structure and function due to global change, including potential impacts on estuarine eutrophication.

Surficial geologic map along the Castle Mountain Fault between Houston and Hatcher Pass Road, Alaska

USGS Publications Warehouse

Haeussler, Peter J.

1998-01-01

The surficial geology of the map area is dominated by sedimentary deposits laid down during and after the Naptowne glaciation (Karlstrom, 1964) of late Pleistocene age. During this episode, a large valley glacier flowed westward down the Matanuska Valley along the southern flank of the Talkeetna Mountains. The youngest of two documented advances has been referred to as the Elmendorf stade, which reached its maximum extent about 12,000 radiocarbon years ago (Schmoll and others, 1972; Reger and Updike, 1983). Deposits from this stade in the map area include: glacial till (Qg), lateral moraine (Qml) and kame terrace (Qk) deposits. Older episodes of glaciation have been inferred by a number of workers (e.g., Karlstrom, 1964; Reger and Updike, 1983; Reger and Updike, 1989; Schmoll and Yehle, 1986). The ridge above and north of the map area, Bald Mountain Ridge, is rounded in contrast to higher areas of the Talkeetna Mountains to the east. Therefore, within the map area older glacial deposits (Qg2) are inferred to lie above the highest Naptowne deposits. After reaching its maximum extent the valley glacier stagnated (Reger and Updike, 1983), as indicated by a crevasse-fill-ridge complex south of Houston in the map area, perched drainages along the sides of the Talkeetna Mountains, and an esker (unit Qe in the middle of the western map area). The ancient stream deposits (unit Qad) are perched on the southern flanks of the Talkeetna Mountains and were deposited by westward flowing streams as the valley glacier stagnated. These sinuous ancient drainages commonly incised up to 20 m into the underlying glacial till. Because stream flow is not as high today as when the drainages formed, the modern streams flowing within these drainages are underfit, and the ancient drainage courses are commonly filled with peat deposits (Qp). After ice of the Elmendorf stade melted, modern stream courses were established. These include the southward flowing streams on the flank of the Talkeetna Mountains as well as the west-southwestward flowing Little Susitna River. The Little Susitna River cut down through older river terrace deposits (Qat) to form the active alluvial plain (Qaa). Alluvium from the southward flowing streams (Qas) forms alluvial fans on top of, and presumably interfingering with, active alluvium along the Little Susitna River.

Hydrology of the Bayou Bartholomew alluvial aquifer-stream system, Arkansas

USGS Publications Warehouse

Broom, M.E.; Reed, J.E.

1973-01-01

The study area comprises about 3,200 square miles of the Mississippi Alluvial Plain in southeast Arkansas. About 90 percent of the area drains south to the Ouachita River in Louisiana. The alluvial aquifer and the streams are hydraulically connected and are studied as an aquifer-stream system. Bayou Bartholomew is a principal stream of the system. The aquifer is underlain by confining strata of the Jackson Group and Cockfield Formation. The mean annual surface-water yield of the area that drains to the Ouachita River basin is nearly 2 million acre-feet. Flood-control projects have significantly reduced flooding in the area. Basin boundaries and low-flow characteristics of streams have been altered as a result of the flood-control projects and streamflow diversion for irrigation. The direction of ground-water flow generally is southward. Bayou Bartholomew functions mostly as a drain for ground-water flow from the west and as a recharge source to the aquifer east of the bayou. As a result of navigation pools, the Arkansas River is mostly a steady-recharge source to the aquifer. Pumpage from the aquifer and streams increased from about 20,000 acre-feet in 1941 to 237,000 acre-feet in 1970. Estimates of flow, derived from analog analysis but lacking field verification, indicate that recharge to the aquifer in 1970 was about 161,000 acre-feet. About 70 percent of the recharge was by capture from streams as a result of ground-water pumpage. Discharge from the aquifer was about 233,000 acre-feet. About 80 percent of the discharge was through wells. Stream diversion in 1970 from capture and open channel, excluding capture from the Arkansas and Mississippi Rivers, was about 110,000 acre-feet. Return flow to streams from rice irrigation and fishponds was about 60,000 acre-feet. The chemical quality of streamflows is excellent for irrigation. Water from the aquifer generally ranges from permissible to excellent for irrigation. The use of water from the aquifer in the flood-plain area, exclusive of irrigation, is severely limited unless it is treated to remove the iron and reduce the hardness.

Slip slidin' away: A post-glacial environmental history of the Waipaoa River basin

NASA Astrophysics Data System (ADS)

Gomez, Basil; Rosser, Brenda J.

2018-04-01

The dramatic changes that occurred to the post-glacial landscape in the headwaters of the Waipaoa River basin are a consequence of perturbations about the equilibrium that exists between the rate of tectonic uplift and fluvial incision. At times when the amount of coarse sediment delivered to channels exceeds the capacity of streams to remove it, the channel bed rises at the rate of tectonic uplift. Once bedload overcapacity is replaced by undercapacity and the alluvial cover is depleted, streams reestablish contact with bedrock and recuperate the time lost to fluvial incision. The first major perturbation occurred during the final phase of the last glaciation (ca. 33-17.5 cal. ka), when aggradation was driven by a climate-forced variation in the relative supplies of sediment and water. We suggest that the subsequent transformation of channels in the headwaters of the Waipaoa River basin, from alluvial to bedrock, occurred as the atmospheric and oceanic circulation converged on their contemporary patterns ca. 12 cal. ka. A second major perturbation that continues to the present began ca. 1910-1912 CE, when a massive increase in sediment load was accompanied by a modest increase in water discharge after the native vegetation cover in the headwaters was replaced by pasture. The processes of terrace creation and incision are inherently unsteady, and in five interim cases incision was arrested by a transient increase in the thickness of the alluvial cover that was a response to climatic forcing. Events that disrupted the native vegetation cover in the headwaters also modulated patterns of sediment dispersal and accumulation in other parts of the fluvial system and caused rapid, storm-driven infilling of the Poverty Bay Flats. Tectonic subsidence dictates the course of the Waipaoa River across Poverty Bay Flats which, because the modern rate of floodplain construction by vertical accretion is rapid relative to the amount of destruction by lateral channel migration, has remained virtually unchanged for the past 100 years. During this time the channel assumed a narrower, deeper form that is in equilibrium with the contemporary supply of sediment and hydraulic regime.

A Dataset of Rock Strength Along the Mixed Bedrock-alluvial Colorado River-Quantifying a Fundamental Control in Geomorphology

NASA Astrophysics Data System (ADS)

Pederson, J. L.; Bursztyn, N.

2014-12-01

Bedrock strength is a key parameter in slope stability, landscape erosion, and fluvial incision, though it is typically ignored or at best indirectly constrained in models, as with the k erodability parameter in stream-power formulations. Indeed, empirical datasets of rock strength suited to address geomorphic questions are rare, in part because of the difficulty in measuring those rocks that are heterolithic, weak, or poorly exposed. We have completed a large dataset of measured bedrock strength organized by rock units exposed along the length of the trunk Colorado-Green river through the Colorado Plateau of the western U.S. Measurements include Selby RMS, fracturing, and field compressive tests at 168 localities, as well as 672 individual-sample tensile-strength tests in the laboratory. These rock strength results are compared to geomorphic metrics of unit stream power, river gradient, valley-bottom width, and local relief through the arid Colorado Plateau. Our measurements trend coherently and logically with bedrock type and age/induration, especially in the case of tensile strength and when the influence of fracturing is also considered, signs that the dataset is robust. Focusing on bedrock (rather than alluvial) reaches of the fluvial transect and tensile strength, there is a positive rank-correlation and a strong power-law correlation between reach-averaged rock strength and unit stream power, as well as an elegant linear relation between tensile strength and river gradient. To address the problem of immeasureable rock types, we utilize the inverse power-law scaling between tensile strength and valley-bottom width to estimate the "effective" tensile strength of heterolithic, shale-rich bedrock in alluvial reaches. These results suggest that tensile strength varies to at least an order-of-magnitude smaller values than evident with directly testable rocks in this landscape, with implications for scaling erodibility parameters. Overall, results lead to the conclusion that bedrock strength is, in fact, the first-order control on large-scale fluvial geomorphology in the Colorado Plateau. On one hand this is intuitive, yet it highlights the erroneous but common assumption that bedrock erodibility is uniform or of secondary importance in fluvial morphology and landscape evolution.

Integrated Hydrogeological Investigation on the Vulnerability of a Pumping Station at a Losing Stream

NASA Astrophysics Data System (ADS)

Ngueleu Kamangou, Stephane; Vogt, Tobias; Cirpka, Olaf

2010-05-01

River restoration usually includes alteration of the river channel morphology. Thereby the interaction between river and groundwater can be modified. For the design of a river restoration project - especially in the vicinity of a groundwater pumping well for drinking water production - this impact must be predicted. But a good prediction requires a proper understanding of the existing situation. Numerical models help to improve the strategy of a successful river restoration project. The main objective of this study was to investigate the vulnerability of a pumping station located at losing river in northeast Switzerland. Besides the effect that river restoration could create, a particular attention was placed on the effect of a beaver dam in a side channel close to the pumping station. Analysis of field measurements coupled with numerical modeling of the pumping station area improved the understanding of the interactions in the river corridor between the river, side channels and the alluvial aquifer.

Unravelling the relative contribution of bed and suspended sediment load on a large alluvial river

NASA Astrophysics Data System (ADS)

Darby, S. E.; Hackney, C. R.; Parsons, D. R.; Leyland, J.; Aalto, R. E.; Nicholas, A. P.; Best, J.

2017-12-01

The world's largest rivers transport 19 billion tonnes of sediment to the coastal zone annually, often supporting large deltas that rely on this sediment load to maintain their elevation in the face of rising sea level, and to sustain high levels of agricultural productivity and biodiversity. However, the majority of estimates of sediment delivery to coastal regions pertain solely to the suspended fraction of the sediment load, with the bedload fraction often being neglected due to the difficulty in estimating bedload flux and the assumption that bedload contributes a minor (<10%) fraction of the total sediment load. In large rivers, capturing accurate estimates of the suspended- and bed- load fractions is difficult given the large channel widths and depths and the intrusive nature of typical methodologies. Yet, for the successful implementation of sustainable river, and delta, management plans, improved estimates of all fractions of the sediment load are essential. Recent advances in non-intrusive, high-resolution, technology have begun to enable more accurate estimates of bedload transport rates. However, the characterisation of the holistic sediment transport regime of large alluvial rivers is still lacking. Here, we develop a sediment transport rating curve, combining both suspended- and bed- load sediment fractions, for the Lower Mekong River. We define suspended sediment rating curves using the inversion of acoustic return data from a series of acoustic Doppler current profiler surveys conducted through the Lower Mekong River in Cambodia, and into the bifurcating channels of the Mekong delta in Vietnam. Additionally, we detail estimates of bed-load sediment transport determined using repeat multibeam echo sounder surveys of the channel bed. By combining estimates of both fractions of the sediment load, we show the spatial and temporal contribution of bedload to the total sediment load of the Mekong and refine estimates of sediment transport to the Mekong delta. Our results indicate that the time-averaged suspended load transport rates for the Mekong River are 87 MT/yr, whilst bedload transport forms c. < 5% of the total sediment load within the Mekong River. Such estimates are integral to future channel management within this highly threatened river basin.

40Ar/39Ar Temporal Constraints on Eocene Uplift, Subsidence, and Paleohydrology in the Laramide Foreland, Western U. S.

NASA Astrophysics Data System (ADS)

Smith, M. E.; Carroll, A. R.; Singer, B. S.

2004-12-01

Due to their sensitivity to relatively subtle changes in regional drainage patterns, Eocene lake deposits of the Green River Formation offer a unique and richly detailed record of landscape modification caused by orogenic processes in the broken foreland of the western U. S. Recently obtained 40Ar/39Ar age determinations for 22 interbedded tephras provide excellent temporal resolution of this record, and enable inter-basin correlations at an unprecedented level of precision (approaching 2σ uncertainties of ± k.y.). Green River Formation strata span an interval of ~8 m.y., beginning and ending with freshwater fluvial-lacustrine deposits. Two episodes of regional basin closure and evaporite deposition, each lasting ˜1-2 m.y., coincide with evidence for active Laramide faulting at basin margins and increased rates of sediment accumulation. Evaporite deposition therefore appears to have been principally caused by enhanced uplift of basin sills rather than increased aridity. Regional stratigraphic relations, facies types, and 40Ar/39Ar geochronology permit deduction of the following paleodrainage history: 1) > ˜51.3 Ma: Fluvial-lacustrine deposition occurred in greater Green River, Piceance Creek and Uinta basins. The onset of lacustrine deposition is not well-dated due to a paucity of tephras. 2) ˜51.3-49.7 Ma: The greater Green River and Piceance Creek basins both became terminal sinks that received overflow from neighboring freshwater basins. Coarse clastic basin-marginal alluvial strata, cross-cutting fault relations, and pronounced differential subsidence in both basins indicate active uplift of the Uinta Mountains and surrounding ranges. 3) ˜49.7-49.1 Ma: Lake Gosiute expanded in extent, coincident with an influx of water and sediment derived from volcanic centers to the north. Episodic overflow over the eastern Uinta uplift flushed dissolved solutes southward, freshening Lake Gosiute while evaporite deposition continued in Lake Uinta. 4) ˜49.1-48.4 Ma: Fresh water spilled consistently from Lake Gosiute into an expanding Lake Uinta. The saline, organic-rich Mahoghany zone of the Parachute Creek Member was deposited over an interval of 0.6 ± 0.3 m.y. coincident with deposition of the freshwater upper LaClede bed of the Laney Member and alluvial Bridger Formation in the greater Green River Basin. 5) ˜48.4-46.3: Fluvial volcaniclastic sediments progressively filled the greater Green River and Piceance Creek basins. Alluvial and freshwater lacustrine deposition dominated both basins. Saline lake deposition continued unabated in the Uinta Basin. 6) ˜46.3-45.0 Ma: Lake Uinta, limited to the western Uinta Basin, became hydrologic closed as evidenced by bedded evaporite deposition. The change to evaporite deposition coincided with an increase in differential subsidence, reflecting a renewal of tectonic deformation. The up-section disappearance of west-directed volcaniclastic input into the eastern Uinta Basin at ˜46.3 Ma suggests that drainage diversion may also have contributed to hydrologic closure. 7) Following ˜45.0 Ma, Lake Uinta returned to fluvial-lacustrine deposition and was subsequently filled with alluvial deposits.

Relations Among River Stage, Rainfall, Ground-Water Levels, and Stage at Two Missouri River Flood-Plain Wetlands

USGS Publications Warehouse

Kelly, Brian P.

2001-01-01

The source of water is important to the ecological function of Missouri River flood-plain wetlands. There are four potential sources of water to flood-plain wetlands: direct flow from the river channel during high river stage, ground-water movement into the wetlands in response to river-stage changes and aquifer recharge, direct precipitation, and runoff from surrounding uplands. Concurrent measurements of river stage, rainfall, ground-water level, and wetland stage were compared for two Missouri River flood-plain wetlands located near Rocheport, Missouri, to characterize the spatial and temporal relations between river stage, rainfall, ground-water levels and wetland stage, determine the source of water to each wetland, and compare measured and estimated stage and ground-water levels at each site. The two sites chosen for this study were wetland NC-5, a non-connected, 50 feet deep scour constantly filled with water, formed during the flood of 1993, and wetland TC-1, a shallow, temporary wetland intermittently filled with water. Because these two wetlands bracket a range of wetland types of the Missouri River flood plain, the responses of other Missouri River wetlands to changes in river stage, rainfall, and runoff should be similar to the responses exhibited by wetlands NC-5 and TC-1. For wetlands deep enough to intersect the ground-water table in the alluvial aquifer, such as wetland NC-5, the ground-water response factor can estimate flood-plain wetland stage changes in response to known river-stage changes. Measured maximum stage and ground-water-level changes at NC-5 fall within the range of estimated changes using the ground-water response factor. Measured maximum ground-water-level changes at TC-1 are similar to, but consistently greater than the estimated values, and are most likely the result of alluvial deposits with higher than average hydraulic conductivity located between wetland TC-1 and the Missouri River. Similarity between ground-water level and stage hydrography at wetland NC-5 indicate that ground-water-level fluctuations caused by river-stage changes control the stage of wetland NC-5. A 2-day lag time exists between river-stage changes and ground water and stage changes at wetland NC-5. The lack of a measurable response of wetland NC-5 stage to rainfall indicate that rainfall is not a large source of water to wetland NC-5. Stage in wetland TC-1 only increased at high river stage in June and July 1999, and from runoff caused by local rainfall during the winter. The 2-day lag time between peak stages at wetland TC-1 and peak Missouri River stages compared to the 1-day lag time between Missouri River stage and ground-water peaks at wetland TC-1 indicates ground-water flow does not directly affect wetland stage at TC-1, but surface-water flow does affect wetland stage at TC-1 during high river stage. Comparing wetland TC-1 stage to potential water sources indicates the most likely explanation for the rise in stage at wetland TC-1 is surface runoff supplied via seepage through the levees and upward flow of ground water through alluvial deposits of higher hydraulic conductivity during high river stage. The rate of decrease in wetland TC-1 stage was limited by the rate at which ground-water level decreased. Stage response to rainfall at wetland TC-1 during the winter months and no response to greater rainfall amounts during spring and summer months indicate that evapotranspiration may limit the affect of rainfall on stage at wetland TC-1 during the growing season.

Analysis of alluvial hydrostratigraphy using indicator geostatistics, with examples from Santa Clara Valley, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-03-01

Current trends in hydrogeology seek to enlist sedimentary concepts in the interpretation of permeability structures. However, existing conceptual models of alluvial deposition tend to inadequately account for the heterogeneity caused by complex sedimentological and external factors. This dissertation presents three analyses of alluvial hydrostratigraphy using indicator geostatistics. This approach empirically acknowledges both the random and structured qualities of alluvial structures at scales relevant to site investigations. The first analysis introduces the indicator approach, whereby binary values are assigned to borehole-log intervals on the basis of inferred relative permeability; it presents a case study of indicator variography at a well-documented ground-watermore » contamination site, and uses indicator kriging to interpolate an aquifer-aquitard sequence in three dimensions. The second analysis develops an alluvial-architecture context for interpreting semivariograms, and performs comparative variography for a suite of alluvial sites in Santa Clara Valley, California. The third analysis investigates the use of a water well perforation indicator for assessing large-scale hydrostratigraphic structures within relatively deep production zones.« less

Lithologic and hydrologic controls of mixed alluvial-bedrock channels in flood-prone fluvial systems: bankfull and macrochannels in the Llano River watershed, central Texas, USA

USGS Publications Warehouse

Heitmuller, Frank T.; Hudson, Paul F.; Asquith, William H.

2015-01-01

The rural and unregulated Llano River watershed located in central Texas, USA, has a highly variable flow regime and a wide range of instantaneous peak flows. Abrupt transitions in surface lithology exist along the main-stem channel course. Both of these characteristics afford an opportunity to examine hydrologic, lithologic, and sedimentary controls on downstream changes in channel morphology. Field surveys of channel topography and boundary composition are coupled with sediment analyses, hydraulic computations, flood-frequency analyses, and geographic information system mapping to discern controls on channel geometry (profile, pattern, and shape) and dimensions along the mixed alluvial-bedrock Llano River and key tributaries. Four categories of channel classification in a downstream direction include: (i) uppermost ephemeral reaches, (ii) straight or sinuous gravel-bed channels in Cretaceous carbonate sedimentary zones, (iii) straight or sinuous gravel-bed or bedrock channels in Paleozoic sedimentary zones, and (iv) straight, braided, or multithread mixed alluvial–bedrock channels with sandy beds in Precambrian igneous and metamorphic zones. Principal findings include: (i) a nearly linear channel profile attributed to resistant bedrock incision checkpoints; (ii) statistically significant correlations of both alluvial sinuosity and valley confinement to relatively high f (mean depth) hydraulic geometry values; (iii) relatively high b (width) hydraulic geometry values in partly confined settings with sinuous channels upstream from a prominent incision checkpoint; (iv) different functional flow categories including frequently occurring events (< 1.5-year return periods) that mobilize channel-bed material and less frequent events that determine bankfull channel (1.5- to 3-year return periods) and macrochannel (10- to 40-year return periods) dimensions; (v) macrochannels with high f values (most ≤ 0.45) that develop at sites with unit stream power values in excess of 200 watts per square meter (W/m2); and (vi) downstream convergence of hydraulic geometry exponents for bankfull and macrochannels, explained by co-increases of flood magnitude and noncohesive sandy sediments that collectively minimize development of alluvial bankfull indicators. Collectively, these findings indicate that mixed alluvial–bedrock channels exhibit first-order lithologic controls (lithologic resistance and valley confinement) of channel geometry, second-order hydrologic (flow regime) control of channel dimensions, and third-order sedimentary controls that exert subsidiary influence on channel shape and bed configuration.

Examining the spatial and temporal variation of groundwater inflows to a valley-to-floodplain river using 222Rn, geochemistry and river discharge: the Ovens River, southeast Australia

NASA Astrophysics Data System (ADS)

Yu, M. C. L.; Cartwright, I.; Braden, J. L.; de Bree, S. T.

2013-12-01

Radon (222Rn) and major ion geochemistry were used to define and quantify the catchment-scale groundwater-surface water interactions along the Ovens River in the southeast Murray-Darling Basin, Victoria, Australia, between September 2009 and October 2011. The Ovens River is characterized by the transition from a single channel within a mountain valley in the upper catchment to a multi-channel meandering river on flat alluvial plains in the lower catchment. Overall, the Ovens River is dominated by gaining reaches, receiving groundwater from both alluvial and basement aquifers. The distribution of gaining and losing reaches is governed by catchment morphology and lithology. In the upper catchment, rapid groundwater recharge through the permeable aquifers increases the water table. The rising water table, referred to as hydraulic loading, increases the hydraulic head gradient toward the river and hence causes high baseflow to the river during wet (high flow) periods. In the lower catchment, lower rainfall and finer-gained sediments reduce the magnitude and variability of hydraulic gradient between the aquifer and the river, producing lower but more constant groundwater inflows. The water table in the lower reaches has a shallow gradient, and small changes in river height or groundwater level can result in fluctuating gaining and losing behaviour. The middle catchment represents a transition in river-aquifer interactions from the upper to the lower catchment. High baseflow in some parts of the middle and lower catchments is caused by groundwater flowing over basement highs. Mass balance calculations based on 222Rn activities indicate that groundwater inflows are 2 to 17% of total flow with higher inflows occurring during high flow periods. In comparison to 222Rn activities, estimates of groundwater inflows from Cl concentrations are higher by up to 2000% in the upper and middle catchment but lower by 50 to 100% in the lower catchment. The high baseflow estimates using Cl concentrations may be due to the lack of sufficient difference between groundwater and surface water Cl concentrations. Both hydrograph separation and differential flow gauging yield far higher baseflow fluxes than 222Rn activities and Cl concentrations, probably indicating the input of other sources to the river in additional to regional groundwater, such as bank return flows.

Long-term entrenchment and consequences in present flood hazard in Garona River (Val d'Aran, central Pyrenees)

NASA Astrophysics Data System (ADS)

Victoriano-Lamariano, Ane; Garcia-Silvestre, Marta; Furdada-Bellavista, Gloria

2015-04-01

Flood risk is one of the most dangerous natural disasters in mountainous areas. Risk management and mitigation have to be based on exhaustive risk evaluation. Moreover, hazard analysis requires a multidisciplinary approach to achieve a complete understanding of the dynamics of the phenomena. The Val d'Aran valley is located in the axial part of the Pyrenees and is drained by the Garona River. Flooding events are relatively frequent there. The last extraordinary episode occurred in June 2013. Considering both the main effects of this flooding and the geomorphology, the long-term dynamics of the Garona River was studied in two different areas (Arties-Vielha and Era Bordeta-Les), which are representative of the whole length along the Val d'Aran. In fact, present short-term processes can be partly explained as a result of the long-term fluvial tendency. During the analysis of the 2013 flood effects, several entrenchment and incision indicators were found. Under the hypothesis that the fluvial network tends to incise, an entrenchment indicator analysis was carried out. Firstly, we considered the geomorphologic features, such as two generations of alluvial fans, two generations of alluvial terraces and, incisions on geomorphologic features and in Paleozoic bedrock. Secondly, we found out that erosion dominated over overflow and deposition during the 2013 flooding. Finally, great erosion was identified in engineering structures, for instance, in bridges, channelization dikes, gauging stations and dams. The geomorphologic analysis and the entrenchment indicators are essential to perform a post-glacial evolution interpretation. During the last Pleistocene glacial retreat, a fluvio-torrential network was developed at the bottom of the ancient glacial valley. An early post-glacial phase with a high sediment transport lead to the formation of first generation alluvial fans and alluvial terraces (nowadays located ≈15m above the channel). As sediment transport decreased, fluvial incision became preponderant while second generation alluvial fans and floodplains were formed. Therefore, the specific analysis of entrenchment indicators shows evidence of a vertical incision tendency of the drainage network. The obtained data allowed us to estimate an approximate mean entrenchment rate of 1,07 mm/year since the end of the Pleistocene glacial period. Compared with the 0,08-0,19 mm/year regional uplift rate, the dynamics of the Garona River is probably a combination of climatic (interglacial period), tectonic (uplift and erosional tendency of the axial Pyrenees since the Miocene), topographic (high gradients) and anthropic (engineering structures) factors, and also an intense glacial deposits erosion. In conclusion, the incision tendency hypothesis was confirmed, which is directly related to the geomorphological response after the last glaciation and is probably related to the evolution of the Pyrenean axial zone. Moreover, the long-term entrenchment dynamics determines present short-term fluvial processes, produces changes in flood hazard and controls the flood effects (see Garcia-Silvestre et al., also presented in EGU 2015). Thereby, this entrenchment tendency has consequences that must be considered when designing structural mitigation measures against flooding events.

Persistent Urban Impacts on Surface Water Quality Mediated by Stormwater Recharge

NASA Astrophysics Data System (ADS)

Gabor, R. S.; Brooks, P. D.; Neilson, B. T.; Bowen, G. J.; Jameel, M. Y.; Hall, S. J.; Eiriksson, D.; Millington, M. R.; Gelderloos, A.

2016-12-01

Growing population centers along mountain watersheds put added stress on sensitive hydrologic systems and create water quality impacts downstream. We examined the mountain-to-urban transition in watersheds on Utah's Wasatch Front to identify mechanisms by which urbanization impacts water resources. Rivers in the Wasatch flow from the mountains directly into an urban landscape, where they are subject to channelization, stormwater runoff systems, and urban inputs to water quality from sources such as road salt and fertilizer. As part of an interdisciplinary effort within the iUTAH project, multiple synoptic surveys were performed and a variety of measurements were made, including basic water chemistry along with discharge, water isotopes, and nutrients. Red Butte Creek, a stream in Salt Lake City, does not show significant urban impact to water quality until several kilometers after it enters the city where concentrations of solutes such as chloride and nitrate more than triple in a gaining reach. Groundwater springs discharging to this gaining section demonstrate urban-impacted water chemistry, suggesting that during baseflow a contaminated alluvial aquifer significantly controls stream chemistry. By combining hydrometric and hydrochemical observations we were able to estimate that these groundwater springs were 17-20% urban runoff. We were then able to predict the chemistry of urban runoff that feeds into the alluvial aquifer. Samples collected from storm culverts, roofs, and asphalt during storms had chemistry values within the range of those predicted by the mixing model. This evidence that urbanization affects the water quality of baseflow through impacted groundwater suggests that stormwater mitigation may not be sufficient for protecting urban watersheds, and quantifying these persistent groundwater mediated impacts is necessary to evaluate the success of restoration efforts. By comparing these results from Red Butte Creek with similar studies from other rivers in the Wasatch Front and other alluvial systems, we can quantify how characteristics such as discharge patterns and land-use determine alluvial recharge controls on surface water quality.

Effects of Proposed Additional Ground-Water Withdrawals from the Mississippi River Valley Alluvial Aquifer on Water Levels in Lonoke County, Arkansas

USGS Publications Warehouse

Czarnecki, John B.

2006-01-01

The Grand Prairie Water Users Association, located in Lonoke County, Arkansas, plans to increase ground-water withdrawals from the Mississippi River Valley alluvial aquifer from their current (2005) rate of about 400 gallons per minute to 1,400 gallons per minute (2,016,000 gallons per day). The effect of pumping from a proposed well was simulated using a digital model of ground-water flow. The proposed additional withdrawals were added to an existing pumping cell specified in the model, with increased pumping beginning in 2005, and specified to pump at a total combined rate of 2,016,000 gallons per day for a period of 46 years. In addition, pumping from wells owned by Cabot Water Works, located about 2 miles from the proposed pumping, was added to the model beginning in 2001 and continuing through to the end of 2049. Simulated pumping causes a cone of depression to occur in the alluvial aquifer with a maximum decline in water level of about 8.5 feet in 46 years in the model cell of the proposed well compared to 1998 withdrawals. However, three new dry model cells occur south of the withdrawal well after 46 years. This total water-level decline takes into account the cumulative effect of all wells pumping in the vicinity, although the specified pumping rate from all other model cells in 2005 is less than for actual conditions in 2005. After 46 years with the additional pumping, the water-level altitude in the pumped model cell was about 177.4 feet, which is 41.7 feet higher than 135.7 feet, the altitude corresponding to half of the original saturated thickness of the alluvial aquifer (a metric used to determine if the aquifer should be designated as a Critical Ground-Water Area (Arkansas Natural Resources Commission, 2006)).

Suspended sediment impact on chlorophyll a, nitrogen and phosphorus relationships in Moon Lake, MS

USDA-ARS?s Scientific Manuscript database

Moon Lake, MS is a 947 ha. oxbow lake of the Mississippi River Alluvial Plain also known as the Mississippi Delta. Water was sampled from five sites, bi-weekly from 1982 to 1985. Analysis of surface water quality reviled loading of nutrients from nonpoint source pollution associated with agricultu...

Quality assurance of weather parameters for determining daily evapotranspiration in the humid growing environment of the Mid-South

USDA-ARS?s Scientific Manuscript database

Increasingly, producers are relying on irrigation to enhance yields and improve return on investment. The greater demand for ground water to support supplemental irrigation in the Mississippi River Alluvial Flood Plain has resulted in a decline in the aquifer, and a subsequent implementation of more...

The limnology of a Mississippi River alluvial plain oxbow lake following the application of conservation practices

USDA-ARS?s Scientific Manuscript database

From 1995 and 2011 Beasley Lake watershed near Indianola, MS, was subjected to a variety of conservation measures designed to reduce water velocity, erosion and discharge of sediment laden water. Water quality monitoring during the period indicated a number of long term trends and relationships bet...

New Foci of Buruli Ulcer, Angola and Democratic Republic of Congo

PubMed Central

Kibadi, Kapay; Panda, Mbutu; Tamfum, Jean-Jacques Muyembe; Fraga, Alexandra G.; Filho, Adhemar Longatto; Anyo, Gladys; Pedrosa, Jorge; Nakazawa, Yoshinori; Suykerbuyk, Patrick; Meyers, Wayne M.

2008-01-01

We report 3 patients with laboratory-confirmed Buruli ulcer in Kafufu/Luremo, Angola, and Kasongo-Lunda, Democratic Republic of Congo. These villages are near the Kwango/Cuango River, which flows through both countries. Further investigation of artisanal alluvial mining as a risk factor for Buruli ulcer is recommended. PMID:18976574

Winter variation in physiological status of cold stored and freshly lifted semi-evergreen quercus nigra seedlings

Treesearch

Rosa C. Goodman; Douglass F. Jacobs; Kent G. Apostol; Barrett C. Wilson; Emile S. Gardiner

2009-01-01

Water oak (Quercus nigra L.) is a tardily deciduous species commonly planted in afforestation projects in the Lower Mississippi River Alluvial Valley, USA. Field performance is often marked by low survival rates and top dieback, which may be associated with poor physiological quality of planting stock.

A LANDSCAPE ATLAS OF ECOLOGICAL VULNERABILITY: ARKANSAS' WHITE RIVER WATERSHED AND THE MISSISSIPPI ALLUVIAL VALLEY

EPA Science Inventory

In July, 2000 the U.S. EPA's Office of Research and Development was requested to collaborate in a U.S. EPA Region 6 'Regional Applied Research Effort' (RARE). The primary goal of this RARE is to utilize current science and technology to improve the ecological vulnerability asses...

A Numerical Model for Flow and Sediment Transport in Alluvial-River Bends.

DTIC Science & Technology

1983-12-01

into the bend divided by the computed total sediment discharge across the section. This insures that sediment continuity is preserved along the...6 * * * 0 * C YORF DEFINITION’S , C PI : PI !!! BOSTON CREME, APPLE, PUMPKIN , LTC* "" C G = GRAVITATIONAL CONSTANT * r AAA = COEFFICI92T IN

Surface water / groundwater interactions and their spatial variability, an example from the Avon River, South-East Australia

NASA Astrophysics Data System (ADS)

Hofmann, Harald; Cartwright, Ian; Gilfedder, Benjamin

2013-04-01

Understanding the interaction between river water and regional groundwater has significant importance for water management and resource allocation. The dynamics of groundwater/surface water interactions also have implications for ecosystems, pollutant transport, and the quality and quantity of water supply for domestic, agriculture and recreational purposes. After general assumptions and for management purposes rivers are classified in loosing or gaining rivers. However, many streams alternate between gaining and loosing conditions on a range of temporal and spatial scales due to factors including: 1) river water levels in relation to groundwater head; 2) the relative response of the groundwater and river system to rainfall; 3) heterogeneities in alluvial sediments that can lead to alternation of areas of exfiltration and infiltration along a river stretch; and 4) differences in near river reservoirs, such parafluvial flow and bank storage. Spatial variability of groundwater discharge to rivers is rarely accounted for as it is assumed that groundwater discharge is constant over river stretches and only changes with the seasonal river water levels. Riverbank storage and parafluvial flow are generally not taken in consideration. Bank storage has short-term cycles and can contribute significantly to the total discharge, especially after flood events. In this study we used hydrogeochemistry to constrain spatial and temporal differences in gaining and loosing conditions in rivers and investigate potential sources. Environmental tracers, such as major ion chemistry, stables isotopes and Radon are useful tools to characterise these sources. Surface water and ground water samples were taken in the Avon River in the Gippsland Basin, Southwest Australia. Increasing TDS along the flow path from 70 to 250 mg/l, show that the Avon is a net gaining stream. The radon concentration along the river is variable and does not show a general increase downstream, but isolated peaks in some areas instead. Radon concentrations are in general low (under 0.5 Bq/l), but rise significantly when groundwater discharges to the river (up to 3 Bq/l). By using high resolution radon mapping with a water-air-gas-exchanger in combination with EC mapping on a boat we were able to show that groundwater discharge to the river is diffuse on river reaches of about 1 km length where it occurs. The discharge areas are along large alluvial riverbed deposits and are likely to be a mixture of local groundwater and parafluvial flow. High resolution radon mapping has only been used in coastal areas and this is the first study where the method was applied to river systems.

Conceptualization and calibration of anisotropic, dynamic alluvial systems: Pitfalls and biases in current modelling practices

NASA Astrophysics Data System (ADS)

Gianni, Guillaume; Doherty, John; Perrochet, Pierre; Brunner, Philip

2017-04-01

Physical properties of alluvial environments are typically featuring a high degree of anisotropy and are characterized by dynamic interactions between the surface and the subsurface. A literature review on current modelling practice shows that hydrogeological models are often calibrated using isotropic hydraulic conductivity fields and steady state conditions. We aim at understanding how these simplifications affect the predictions of hydraulic heads and exchange fluxes using fully coupled, physically based synthetic models and advanced calibration approaches. Specifically, we present an analysis of the information content provided by averaged, steady state hydraulic data compared to transient data with respect to the determination of aquifer hydraulic properties. We show that the information content in average hydraulic heads is insufficient to inform anisotropic properties of alluvial aquifers and can lead to important biases on the calibrated parameters. We further explore the consequences of these biases on predictions of fluxes and water table dynamics. The results of this synthetic analysis are considered in the calibration of a highly dynamic and anisotropic alluvial aquifer system in Switzerland (the Rhône River). The results of the synthetic and real-world modelling and calibration exercises provide insight on future data acquisition, modelling and calibration strategies for these environments.

Fault-sourced alluvial fans and their interaction with axial fluvial drainage: An example from the Plio-Pleistocene Upper Valdarno Basin (Tuscany, Italy)

NASA Astrophysics Data System (ADS)

Fidolini, Francesco; Ghinassi, Massimiliano; Aldinucci, Mauro; Billi, Paolo; Boaga, Jacopo; Deiana, Rita; Brivio, Lara

2013-05-01

The present study deals with the fault-sourced, alluvial-fan deposits of the Plio-Pleistocene Upper Valdarno Basin (Northern Apennines, Italy). Different phases of alluvial fan aggradation, progradation and backstep are discussed as possible effects of the interaction among fault-generated accommodation space, sediment supply and discharge variations affecting the axial fluvial drainage. The Upper Valdarno Basin, located about 35 km SE of Florence, is filled with 550 m palustrine, lacustrine and alluvial deposits forming four main unconformity-bounded units (i.e. synthems). The study alluvial-fan deposits belong to the two uppermost synthems (Montevarchi and Torrente Ciuffenna synthems) and are Early to Middle Pleistocene in age. These deposits are sourced from the fault-bounded, NE margin of the basin and interfinger with axial fluvial deposits. Alluvial fan deposits of the Montevarchi Synthem consist of three main intervals: i) a lower interval, which lacks any evidence of a depositional trend and testify balance between the subsidence rate (i.e. fault activity) and the amount of sediment provided from the margin; ii) a coarsening-upward middle interval, pointing to a decrease in subsidence rate associated with an augment in sediment supply; iii) a fining-upward, upper interval (locally preserved), documenting a phase of tectonic quiescence associated with a progressive re-equilibration of the tectonically-induced morphological profile. The basin-scale unconformity, which separates the Montevarchi and Torrente Ciuffenna synthems was due to the entrance of the Arno River into the basin as consequence of a piracy. This event caused a dramatic increase in water discharge of the axial fluvial system, and its consequent embanking. Such an erosional surface started to develop in the axial areas, and propagated along the main tributaries, triggering erosion of the alluvial fan deposits. Alluvial-fan deposits of the Torrente Ciuffenna Synthem accumulated above the unconformity during a phase of tectonic quiescence, and show a fining-upward depositional trend. This trend was generated by a progressive decrease in sediment supply stemming out from upstream migration of the knickpoints developed during the embanking of the axial system.

Sprague River geomorphology studies, Klamath Basin, Oregon

NASA Astrophysics Data System (ADS)

McDowell, P. F.; O'Connor, J. E.; Lind, P.

2005-12-01

The Sprague River drains 4050 square kilometers with a mean annual discharge of 16.3 m3/s before emptying into the Williamson River and then upper Klamath Lake in southcentral Oregon. The alternating wide alluvial segments and narrow canyon reaches of this 135-km-long westward flowing river provide for a variety of valued ecologic conditions and human uses along the river corridor, notably fisheries (including two endangered species of suckers, and formerly salmon), timber harvest, agriculture, and livestock grazing. The complex history of land ownership and landuse, water control and diversion structures, and fishery alterations, provides several targets for attributing historic changes to channel and floodplain conditions. Recently, evolving societal values (as well as much outside money) are inspiring efforts by many entities to 'restore' the Sprague River watershed. In cooperation with the U.S. Fish and Wildlife Service, the Klamath Tribes, and many local landowners, we are launching an analysis of Sprague River channel and floodplain processes. The overall objective is to guide restoration activities by providing sound understanding of local geomorphic processes and conditions. To do this we are identifying key floodplain and channel processes, and investigating how they have been affected by historic floodplain activites and changes to the watershed. This is being accomplished by analysis of historic aerial photographs and maps, stratigraphic analysis of floodplain soils and geologic units, mapping of riparian vegetation conditions and changes, and quantitative analysis of high resolution LiDAR topography acquired for the entire river course in December 2004. Preliminary results indicate (1) much of the coarser (and more erodible) floodplain soils are largely composed of pumice deposited in the basin by the 7700 year BP eruption of Mount Mazama; and (2) the LiDAR digital elevation models provide a ready means of subdividing the river into segments with quantifiably different characteristics of channel width, sinuosity, slope, and incision (relative to adjacent floodplain elevations).

Reconstructing Sediment Supply, Transport and Deposition Behind the Elwha River Dams

NASA Astrophysics Data System (ADS)

Beveridge, C.

2017-12-01

The Elwha River watershed in Olympic National Park of Washington State, USA is predominantly a steep, mountainous landscape where dominant geomorphic processes include landslides, debris flows and gullying. The river is characterized by substantial variability of channel morphology and fluvial processes, and alternates between narrow bedrock canyons and wider alluvial reaches for much of its length. Literature suggests that the Elwha watershed is topographically and tectonically in steady state. The removal of the two massive hydropower dams along the river in 2013 marked the largest dam removal in history. Over the century long lifespan of the dams, approximately 21 million cubic meters of sediment was impounded behind them. Long term erosion rates documented in this region and reservoir sedimentation data give unprecedented opportunities to test watershed sediment yield models and examine dominant processes that control sediment yield over human time scales. In this study, we aim to reconstruct sediment supply, transport and deposition behind the Glines Canyon Dam (most upstream dam) over its lifespan using a watershed modeling approach. We developed alternative models of varying complexity for sediment production and transport at the network scale driven by hydrologic forcing. We simulate sediment supply and transport in tributaries upstream of the dam. The modeled sediment supply and transport dynamics are based on calibrated formulae (e.g., bedload transport is simulated using Wilcock-Crowe 2003 with modification based on observed bedload transport in the Elwha River). Observational data that aid in our approach include DEM, channel morphology, meteorology, and streamflow and sediment (bedload and suspended load) discharge. We aim to demonstrate how the observed sediment yield behind the dams was influenced by upstream transport supply and capacity limitations, thereby demonstrating the scale effects of flow and sediment transport processes in the Elwha River watershed.

[The role of the floodplain gradient in structuring of testate amoebae communities in the Ilych River].

PubMed

Mazeĭ, Iu A; Malysheva, E A; Lapteva, E M; Komarov, A A; Taskaeva, A A

2012-01-01

Forty-two testate amoebae taxa were identified in alluvial soils of floodplain islands in the Ilych River. Among the pedo- and eurybionts, there were aquatic rhizopods. Along the floodplain transect (willow --> meadow --> deciduous forest --> coniferous forest), the testate amoebae community changed directly. There are spatially homogeneous (low beta-diversity) testacean communities but species rich on the local level (high alpha-diversity) within forests. Within willows and meadows, communities are characterized by low alpha-diversity and high heterogeneity that leads to high gamma-diversity.

A mass-wasting dominated Quaternary mountain range, the Coastal Range in eastern Taiwan

NASA Astrophysics Data System (ADS)

Hsieh, Meng-Long; Hogg, Alan; Song, Sheng-Rong; Kang, Su-Chen; Chou, Chun-Yen

2017-12-01

Fluvial bedrock incision, which creates topographic relief and controls hillslope development, has been considered the key medium linking denudation and tectonic uplift of unglaciated mountains. This article, however, shows a different scenario from the Coastal Range in eastern Taiwan. This range, with the steepness inherited from pre-orogenic volcanoes, has been subject to mass wasting even before its emergence above sea level no earlier than Middle Pleistocene. Numerous terraced alluvial fans/fan deltas record the ancient mass movements of the range, including rock avalanches. Multiple radiocarbon dates <16 ka cal BP reveal the recurrence intervals of these movements of over several thousand years. The largest event is dated ∼15 ka cal BP, and the two second largest, 9-8 ka cal BP. These mass movements were sourced from ridges with minimum heights of 350-400 m, have sequences not clearly related to the known climate-change events, and are believed to have been triggered mainly by severe rainfall events, large earthquakes, or their combinations. The resulting fluctuation of sediment yield has episodically changed river behavior, forming river terraces in catchments >1 km2. Alluvial terraces are typically exhibited close to the source ridges of mass movements, and strath terraces along the downstream parts of rivers. Both were created when enormous sediment supply had exceeded or matched the prevailing river transport capacity. This process, along with the protection by giant boulders from mass movement, disturbed the long-term incision trend of rivers in response to tectonic uplift. As a result, the observed Holocene bedrock incision at most sites has not kept pace with the tectonic uplift. The spatial contrast in mass-wasting histories further accounts for the great diversity of the terrace sequences, even in areas with similar tectonic and base-level conditions.

Surficial geologic maps along the riparian zone of the Animas River and its headwater tributaries, Silverton to Durango, Colorado, with upper Animas River watershed gradient profiles

USGS Publications Warehouse

Blair, R.W.; Yager, D.B.; Church, S.E.

2002-01-01

This product consists of Adobe Acrobat .PDF format documents for 10 surficial geologic strip maps along the Animas River watershed from its major headwater tributaries, south to Durango, Colorado. The Animas River originates in the San Juan Mountains north of the historic mining town of Silverton, Colorado. The surficial geologic maps identify surficial deposits, such as flood-plain and terrace gravels, alluvial fans, glacial till, talus, colluvium, landslides, and bogs. Sixteen primary units were mapped that included human-related deposits and structures, eight alluvial, four colluvial, one glacial, travertine deposits, and undifferentiated bedrock. Each of the surficial geologic strip maps has .PDF links to surficial geology photographs, which enable the user to take a virtual tour of these deposits. Geochemical data collected from mapped surficial deposits that pre- and postdate mining activity have aided in determining the geochemical baseline in the watershed. Several photographs with their corresponding geochemical baseline profiles are accessible through .PDF links from several of the maps. A single coverage for all surficial deposits mapped is included as an ArcInfo shape file as an Arc Export format .e00 file. A gradient map for major headwater tributary streams to the Animas River is also included. The gradient map has stream segments that are color-coded based on relative variations in slope and .PDF format links to each stream gradient profile. Stream gradients were derived from U.S. Geological Survey 10-m digital elevation model data. This project was accomplished in support of the U.S. Geological Survey's Abandoned Mine Lands Initiative in the San Juan Mountains, Colorado.

Facies analysis, palaeoenvironmental reconstruction and stratigraphic development of the Early Cretaceous sediments (Lower Bima Member) in the Yola Sub-basin, Northern Benue Trough, NE Nigeria

NASA Astrophysics Data System (ADS)

Sarki Yandoka, Babangida M.; Abubakar, M. B.; Abdullah, Wan Hasiah; Amir Hassan, M. H.; Adamu, Bappah U.; Jitong, John S.; Aliyu, Abdulkarim H.; Adegoke, Adebanji Kayode

2014-08-01

The Benue Trough of Nigeria is a major rift basin formed from the tension generated by the separation of African and South American plates in the Early Cretaceous. It is geographically sub-divided into Southern, Central and Northern Benue portions. The Northern Benue Trough comprises two sub-basins; the N-S trending Gongola Sub-basin and the E-W trending Yola Sub-basin. The Bima Formation is the oldest lithogenetic unit occupying the base of the Cretaceous successions in the Northern Benue Trough. It is differentiated into three members; the Lower Bima (B1), the Middle Bima (B2) and the Upper Bima (B3). Facies and their stratigraphical distribution analyses were conducted on the Lower Bima Member exposed mainly at the core of the NE-SW axially trending Lamurde Anticline in the Yola Sub-basin, with an objective to interpret the paleodepositional environments, and to reconstruct the depositional model and the stratigraphical architecture. Ten (10) lithofacies were identified on the basis of lithology, grain size, sedimentary structures and paleocurrent analysis. The facies constitute three (3) major facies associations; the gravelly dominated, the sandy dominated and the fine grain dominated. These facies and facies associations were interpreted and three facies successions were recognized; the alluvial-proximal braided river, the braided river and the lacustrine-marginal lacustrine. The stratigraphic architecture indicates a rifted (?pull-apart) origin as the facies distribution shows a progradational succession from a shallow lacustrine/marginal lacustrine (at the axial part of the basin) to alluvial fan (sediment gravity flow)-proximal braided river (gravel bed braided river) and braided river (channel and overbank) depositional systems. The facies stacking patterns depict sedimentation mainly controlled by allogenic factors of climate and tectonism.

Assessing overland sediment transport to the Apalachicola River/Bay in Florida

NASA Astrophysics Data System (ADS)

Smar, D. E.; Hagen, S.; Daranpob, A.; Passeri, D.

2011-12-01

An ongoing study in Franklin County, Florida is focused on classifying the mechanisms of sediment transport from the overland areas to eventual deposition in the Apalachicola River and surrounding estuaries. Sediment cores and water column samples were collected at various locations along the Apalachicola River, its tributaries, and distributaries over a two-week period during the wet season. A preliminary particle size distribution analysis of the sediment cores and water column samples demonstrates decreasing particle sizes as the river and wetlands progress toward the ocean. Daily water samples from the mouth of the Apalachicola River and two distributaries reveal fluctuating total suspended solid (TSS) concentrations. To understand these deviations, flow rate and water level at each location is inspected. Because the nearest USGS gage is approximately 16 miles upstream from these sites, investigation of the hydrodynamic influences of sediment transport is conducted by developing a hydrodynamic model simulating river flow and tides in the Apalachicola River and bay system. With spatially accurate flow rates and water levels, an attempt can be made to correlate flow rate with fluctuating TSS concentrations. Precipitation events during the sampling period also support spikes in the TSS concentrations as expected. Assessing sediment transport to the river/bay system will lead to a better understanding of the regression or accretion of the river's alluvial fan and the marsh platform. High flow periods following extreme rain events (which are expected to intensify under global climate change) transport more sediment downstream, however, the interaction with tidal and sea level effects are still being analyzed. With rising sea levels, it is expected that the alluvial fan will recede and wetland areas may migrate inland gradually transforming existing dry lands such as pine forests into new wetland regions. Future work will include an analysis of the tidal cycle during the sampling period to more accurately classify fluctuation of TSS concentration in the downstream samples. The data collection process and laboratory analysis will also be repeated in the dry season, and subsequent years to observe temporal trends.

Late Cenozoic surficial deposits and valley evolution of unglaciated northern New Jersey

USGS Publications Warehouse

Stanford, S.D.

1993-01-01

Multiple alluvial, colluvial, and eolian deposits in unglaciated northern New Jersey, and the eroded bedrock surfaces on which they rest, provide evidence of both long-term valley evolution driven by sustained eustatic baselevel lowering and short-term filling and excavation of valleys during glacial and interglacial climate cycles. The long-term changes occur over durations of 106 years, the short-term features evolve over durations of 104 to 105 years. Direct glacial effects, including blockage of valleys by glacial ice and sediment, and valley gradient reversals induced by crustal depression, are relatively sudden changes that account for several major Pleistocene drainage shifts. After deposition of the Beacon Hill fluvial gravel in the Late Miocene, lowering of sea level, perhaps in response to growth of the Antarctic ice sheet, led to almost complete dissection of the gravel. A suite of alluvial, colluvial, and eolian sediments was deposited in the dissected landscape. The fluvial Bridgeton Formation was deposited in the Raritan lowland, in the Amboy-Trenton lowland, and in the Delaware valley. Following southeastward diversion of the main Bridgeton river, perhaps during Late Pliocene or Early Pleistocene glaciation, northeastward drainage was established on the inactive Bridgeton fluvial plain. About 30 to 45 m of entrenchment followed, forming narrow, incised valleys within which Late Pleistocene deposits rest. This entrenchment may have occurred in response to lowered sea level caused by growth of ice sheets in the northern hemisphere. Under periglacial conditions in the Middle and Late Pleistocene, valleys were partially filled with alluvium and colluvium. During interglacials slopes were stabilized by vegetation and the alluvial and colluvial valley-fill was excavated by gullying, bank erosion, and spring sapping. During Illinoian and late Wisconsinan glaciation, the lower Raritan River was diverted when glacial deposits blocked its valley, and the Delaware River was partially diverted down the isostatically-steepened lower Millstone valley. ?? 1993.

Seismic response in archaeological areas: the case-histories of Rome

NASA Astrophysics Data System (ADS)

Donati, Stefano; Funiciello, Renato; Rovelli, Antonio

1999-03-01

Rome is affected by earthquakes associated to three different seismogenic districts: the Central Apennines area, the Colli Albani volcanic area and the Roman area. The major effects were exclusively due to Apennine seismicity and reached in some cases felt intensities up to VII-VIII degree (MCS scale). The predominant role in the damage distribution seems to be played by the local geological conditions. The historical centre of the city is characterized by the presence of two geomorphologic domains: the alluvial plain of Tiber river and the topographic relieves of Roman Hills, where tradition indicates the first site of the city foundation. In particular, the right river side is characterized by the outcropping of the regional bedrock along the Monte Mario-Gianicolo ridge, while the eastern relieves are the remnants of the Sabatini and Albani volcanic plateau, deeply eroded by the Tiber river and its tributaries during the last glacial low-stand (Würm). These domains are characterized by a large difference in seismic response, due to the high impedance contrast between Holocene coarse deposits filling the Tiber Valley and sedimentary and volcanic Plio-Pleistocene units. Seismic damage observed in 150 monuments of downtown Rome was indicating a significant concentration on alluvial recent deposits. This result was confirmed by the geographical distribution of conservation and retrofitting activities subsequent to main earthquakes, mostly related to local geological conditions. The cases of Marcus Aurelius' Column and Colosseum confirmed the influence of the Holocene alluvial network in local seismic response. During 2500 years of history, the monuments of Rome have `memorized' the seismic effects of historical earthquakes. In some cases, the integration of historical and geological research and macroseismic observations may provide original and useful indications to seismologists to define the seismic response of the city. Local site effects represent a serious threat for historical buildings in Rome and in other historical towns with similar cultural heritage and geological characteristics, as in the Mediterranean region, even in areas that are not affected by a local seismic activity.

Anthropogenic and geomorphic controls on peatland dynamics in contrasting floodplain environments during the Holocene and its impact on carbon storage

NASA Astrophysics Data System (ADS)

Verstraeten, Gert; Broothaerts, Nils; Notebaert, Bastiaan

2016-04-01

Peatlands are an important store of carbon in terrestrial environments, and scientific interest in peatlands has increased strongly in the light of the recent global climatic changes. Much attention has been paid to peatland dynamics in extensive arctic and boreal wetlands or to blanket peat in temperate regions. Nevertheless, long-term dynamics of peat in alluvial wetlands in temperate regions remains largely underresearched. In this study, data from three contrasting environments were used to provide more insights in the anthropogenic and geomorphic controls on peatland dynamics. The results show a high variability in alluvial peatland dynamics between the different study sites. In the central Belgian Loess Belt, alluvial peatlands developed during the early Holocene but gradually disappeared from the Mid-Holocene onwards due to the gradual intensification of agricultural activities in the catchment and consequent higher sedimentation rates in the floodplain system. The end of peat growth is shown to be diachronous at catchment scale, ranging between 6500 and 500 cal a BP. The disappearance of the alluvial peatlands has important implications since it potentially reduces the storage of locally produced C. Nevertheless, it was shown that this reduced production of local C but was outbalanced by the burial of hillslope derived C. Also within the sandy catchments of the Belgian Campine region alluvial peatlands initiated in the early Holocene but, here, they abruptly disappeared in the Mid-Holocene before the onset of intense agricultural activities in the catchment. This suggests that for the sandy regions, anthropogenic impact on peatland dynamics is less important compared to natural factors. For these regions, the disappearance of alluvial peatland formation resulted in a sharp decline in alluvial carbon storage as there is no compensation through hillslope derived C input. For the upper Dee catchment in NE Scotland, Holocene carbon floodplain storage varies strongly along the river gradient as a result of varying geomorphic conditions and changes in hillslope-valley connectivity that control alluvial peatland formation. Overall, alluvial peatland dynamics are shown to be highly variable, in space, timing, rate of changes and controlling factors. This has important implications on C-storage studies and questions the possibilities of extrapolation of single site studies towards larger areas.

Use of carboxylated microspheres to assess transport potential of Cryptosporidium parvum oocysts at the Russian River water supply facility, Sonoma County, California

USGS Publications Warehouse

Metge, D.W.; Harvey, R.W.; Anders, R.; Rosenberry, D.O.; Seymour, D.; Jasperse, James

2007-01-01

Carboxylated microspheres were employed as surrogates to assess the transport potential of Cryptosporidium parvumoocysts during forced- and natural-gradient tests conducted in July and October 2004. The tests involved poorly-sorted, near-surface sediments where groundwater is pumped from an alluvial aquifer underlying the Russian River, Sonoma County, CA. In an off channel infiltration basin and within the river, a mixture (2-, 3-, and 5- ??m diameters) of fluorescently-labeled carboxylated microspheres and bromide tracers were used in two injection and recovery test to assess sediment removal efficiency for the microspheres. Bottom sediments varied considerably in their filtration efficiency for Cryptosporidium.

Geologic map of the Topock 7.5’ quadrangle, Arizona and California

USGS Publications Warehouse

Howard, Keith A.; John, Barbara E.; Nielson, Jane E.; Miller, Julia M.G.; Wooden, Joseph L.

2013-01-01

The Topock quadrangle exposes a structurally complex part of the Colorado River extensional corridor and also exposes deposits that record landscape evolution during the history of the Colorado River. Paleoproterozoic gneisses and Mesoproterozoic granitoids and intrusive sheets are exposed through tilted cross-sectional thicknesses of many kilometers. Intruding them are a series of Mesozoic to Tertiary igneous rocks including dismembered parts of the Late Cretaceous Chemehuevi Mountains Plutonic Suite. Plutons of this suite in Arizona, if structurally restored for Miocene extension, formed cupolas capping the Chemehuevi Mountains batholith in California. Thick (1–3 km) Miocene sections of volcanic rocks, sedimentary breccias, conglomerate, and sandstone rest nonconformably on the Proterozoic rocks and record the structural and depositional evolution of the Colorado River extensional corridor. Four major Miocene low-angle normal faults and a steep block-bounding fault that developed during this episode divide the deformed rocks of the quadrangle into major structural plates and tilted blocks in and east of the Chemehuevi Mountains core complex. The low-angle faults attenuate crustal section, superposing supracrustal and upper crustal rocks against gneisses and granitoids originally from deeper crustal levels. The transverse block-bounding Gold Dome Fault Zone juxtaposes two large hanging-wall blocks, each tilted 90°, and the fault zone splays at its tip into folds in layered Miocene rocks. A synfaulting intrusion occupies the triangular zone where the folded strata detached from an inside corner along this fault between the tilt blocks. Post-extensional upper Miocene to Quaternary strata, locally deformed, record post-extensional landscape evolution, including several Pliocene and younger aggradational episodes in the Colorado River valley and intervening degradation episodes. The aggradational sequences include (1) the Bouse Formation, (2) fluvial deposits correlated with the alluvium of Bullhead City, (3) the younger fluvial boulder conglomerate of Bat Cave Wash, (4) the fluvial Chemehuevi Formation and related valley-margin deposits, and (5) fluvial Holocene deposits under the river and the valley floor. These fluvial records of Colorado River deposition are interspersed with piedmont alluvial fan deposits of several ages.

A postglacial chronology for some alluvial valleys in Wyoming

USGS Publications Warehouse

Leopold, Luna Bergere; Miller, John P.

1954-01-01

Alluvial terraces were studied in several major river basins in eastern Wyoming. Three terraces are present along nearly all the streams and large tributaries. There are several extensive dissected erosion surfaces in the area, but these are much older than, and stand well above, the recent alluvial terraces with which this report is concerned.The three alluvial terraces stand respectively about 40, 10, and 5 feet above the present streams. The uppermost and oldest is a fill terrace comprised of three stratigraphic units of varying age. The oldest unit is Pleistocene and the youngest unit postdates the development of a soil zone, or paleosol, which is characterized by strong accumulation of calcium carbonate and gypsum. This paleosol is an important stratigraphic marker. The middle terrace is generally a cut terrace and is developed on the material making up the youngest alluvium of the high terrace. The lowest is a fill terrace, the surface of which is only slightly higher than the present flood plain.The oldest terrace can tentatively be traced into mountain valleys of the Bighorn Range on the basis of discontinuous remnants. The terrace remnants occur far upstream from the youngest moraine in the valleys studied. On this basis, the terrace sequence is considered to postdate the last Wisconsin ice in the Bighorn Mountains. The paleosol is tentatively correlated with Altithermal time, called in Europe the Climatic Optimum. The terrace sequence is very similar to that suggested by various workers in the southwestern United States.Two streams, Clear Creek and the Powder River, deposited comparable silty alluvium, the surface of which now comprises the highest alluvial terrace. The gradients of these former flood plains differed markedly between the two streams despite the comparability in size of material deposited. This difference in gradient is believed to have required different relative contributions of water from mountain and plain areas than now exist.Knowledge of Recent physiographic history of the area is the basis of determining the relative ages of some gully features. Certain vertical-walled channels or arroyos that might appear to be attributable to postsettlement grazing or other man-induced influences are shown to be Recent but pre-Columbian in age. Such differentiation in age of erosion features is necessary for proper understanding of present-day soil erosion problems.

Restoration of areas degraded by alluvial sand mining: use of soil microbiological activity and plant biomass growth to assess evolution of restored riparian vegetation.

PubMed

Venson, Graziela R; Marenzi, Rosemeri C; Almeida, Tito César M; Deschamps-Schmidt, Alexandre; Testolin, Renan C; Rörig, Leonardo R; Radetski, Claudemir M

2017-03-01

River or alluvial sand mining is causing a variety of environmental problems in the Itajaí-açú river basin in Santa Catarina State (south of Brazil). When this type of commercial activity degrades areas around rivers, environmental restoration programs need to be executed. In this context, the aim of this study was to assess the evolution of a restored riparian forest based on data on the soil microbial activity and plant biomass growth. A reference site and three sites with soil degradation were studied over a 3-year period. Five campaigns were performed to determine the hydrolysis of the soil enzyme fluorescein diacetate (FDA), and the biomass productivity was determined at the end of the studied period. The variation in the enzyme activity for the different campaigns at each site was low, but this parameter did differ significantly according to the site. Well-managed sites showed the highest biomass productivity, and this, in turn, showed a strong positive correlation with soil enzyme activity. In conclusion, soil enzyme activity could form the basis for monitoring and the early prediction of the success of vegetal restoration programs, since responses at the higher level of biological organization take longer, inhibiting the assessment of the project within an acceptable time frame.

The Graded Alluvial River: Variable Flow and the Dominant Discharge

NASA Astrophysics Data System (ADS)

Blom, A.; Arkesteijn, L.; Viparelli, E.

2016-12-01

We derive analytical formulations for the graded or equilibrium longitudinal profile of a mixed-sediment alluvial river under variable flow. The formulations are applicable to reaches upstream from the backwater zone. The model is based on the conservation equations for the mass of two distinct sediment modes, sand and gravel, at the bed surface to account for the effects of grain size selective transport and abrasion of gravel particles. The effects of a variable flow rate are included by (a) treating the flow as a continuously changing yet steady water discharge (i.e. here termed an alternating steady discharge) and (b) assuming the time scale of changes in channel slope and bed surface texture to be much larger than the one of changes in flow rate. The equations are simplified realizing that at equilibrium the river profile finds itself in a dynamic steady state with oscillations around constant mean values of channel slope and bed surface texture. A generalized sediment transport relation representing the stochastic nature of sediment transport allows for explicit or analytical solutions to the streamwise decrease of both the channel slope and the bed surface mean grain size under variable flow for reaches unaffected by backwater effects. This modelling approach also provides a definition of a channel-forming or dominant water discharge, i.e., that steady water discharge that is equivalent in its effect on the equilibrium channel slope to the full hydrograph.

Unintended consequences of biofuels production?The effects of large-scale crop conversion on water quality and quantity

USGS Publications Warehouse

Welch, Heather L.; Green, Christopher T.; Rebich, Richard A.; Barlow, Jeannie R.B.; Hicks, Matthew B.

2010-01-01

In the search for renewable fuel alternatives, biofuels have gained strong political momentum. In the last decade, extensive mandates, policies, and subsidies have been adopted to foster the development of a biofuels industry in the United States. The Biofuels Initiative in the Mississippi Delta resulted in a 47-percent decrease in cotton acreage with a concurrent 288-percent increase in corn acreage in 2007. Because corn uses 80 percent more water for irrigation than cotton, and more nitrogen fertilizer is recommended for corn cultivation than for cotton, this widespread shift in crop type has implications for water quantity and water quality in the Delta. Increased water use for corn is accelerating water-level declines in the Mississippi River Valley alluvial aquifer at a time when conservation is being encouraged because of concerns about sustainability of the groundwater resource. Results from a mathematical model calibrated to existing conditions in the Delta indicate that increased fertilizer application on corn also likely will increase the extent of nitrate-nitrogen movement into the alluvial aquifer. Preliminary estimates based on surface-water modeling results indicate that higher application rates of nitrogen increase the nitrogen exported from the Yazoo River Basin to the Mississippi River by about 7 percent. Thus, the shift from cotton to corn may further contribute to hypoxic (low dissolved oxygen) conditions in the Gulf of Mexico.

Understory vegetation as an indicator for floodplain forest restoration in the Mississippi River Alluvial Valley, U.S.A.

USGS Publications Warehouse

De Steven, Diane; Faulkner, Stephen; Keeland, Bobby D.; Baldwin, Michael; McCoy, John W.; Hughes, Steven C.

2015-01-01

In the Mississippi River Alluvial Valley (MAV), complete alteration of river-floodplain hydrology allowed for widespreadconversion of forested bottomlands to intensive agriculture, resulting in nearly 80% forest loss. Governmental programs haveattempted to restore forest habitat and functions within this altered landscape by the methods of tree planting (afforestation)and local hydrologic enhancement on reclaimed croplands. Early assessments identified factors that influenced whetherplanting plus tree colonization could establish an overstory community similar to natural bottomland forests. The extentto which afforested sites develop typical understory vegetation has not been evaluated, yet understory composition may beindicative of restored site conditions. As part of a broad study quantifying the ecosystem services gained from restorationefforts, understory vegetation was compared between 37 afforested sites and 26 mature forest sites. Differences in vegetationattributes for species growth forms, wetland indicator classes, and native status were tested with univariate analyses;floristic composition data were analyzed by multivariate techniques. Understory vegetation of restoration sites was generallyhydrophytic, but species composition differed from that of mature bottomland forest because of young successional age anddiffering responses of plant growth forms. Attribute and floristic variation among restoration sites was related to variationin canopy development and local wetness conditions, which in turn reflected both intrinsic site features and outcomes ofrestoration practices. Thus, understory vegetation is a useful indicator of functional progress in floodplain forest restoration.

Photosynthesis of Nuttall oak (Quercus nuttallii Palm.) seedlings interplanted beneath an eastern cottonwood (Populus deltoides Bartr. Ex Marsh.) nurse crop

Treesearch

Emile S. Gardiner; Callie J. Schweitzer; John A. Stanturf

2001-01-01

An afforestation system which utilizes the pioneer species eastern cottonwood (Populus deltoides Bartr. ex Marsh.) as a nurse for slower growing, disturbance-dependent species is under evaluation as a forest rehabilitation tool on former agricultural land in the Lower Mississippi River Alluvial Valley, USA. The primary objectives...

Hydrogeology and water quality in the Cedar Rapids area, Iowa, 1992-96

USGS Publications Warehouse

Schulmeyer, P.M.; Schnoebelen, D.J.

1998-01-01

Several areas in the Cedar River alluvial aquifer with large iron and manganese concentrations could be related to the original depositional environment of the sediment. In general, large iron and manganese concentrations in ground water are often associated with abundant organic and argillaceous material in sediment near old meander channels and sloughs.

Identify temporal trend of air temperature and its impact on forest stream flow in Lower Mississippi River Alluvial Valley using wavelet analysis

USDA-ARS?s Scientific Manuscript database

Characterization of stream flow is essential to water resource management, water supply planning, environmental protection, and ecological restoration; while climate change can exacerbate stream flow and add instability to the flow. In this study, the wavelet analysis technique was employed to asse...

Chapter 16 - conservation and use of coastal wetland forests in Louisiana

Treesearch

Stephen P. Faulkner; Jim L. Chambers; William H. Conner; Richard F. Keim; John W. Day; Emile S. Gardiner; Melinda S. Hughes; Sammy L. King; Kenneth W. McLeod; Craig A. Miller; J. Andrew Nyman; Gary P. Shaffer

2007-01-01

The natural ecosystems of coastal Louisiana reflect the underlying geomorphic processes responsible for their formation. The majority of Louisiana's wetland forests are found in the lower reaches of the Mississipp Alluvial Valley and the Deltaic Plain. The sediments, water, and energy of the Mississippi River have shaped the Deltaic Plain as natural deltas have...

Valley-fill alluviation during the Little Ice Age (ca. A.D. 1400-1880), Paria River basin and southern Colorado Plateau, United States

USGS Publications Warehouse

Hereford, R.

2002-01-01

Valley-fill alluvium deposited from ca. A.D. 1400 to 1880 is widespread in tributaries of the Paria River and is largely coincident with the Little Ice Age epoch of global climate variability. Previous work showed that alluvium of this age is a mappable stratigraphic unit in many of the larger alluvial valleys of the southern Colorado Plateau. The alluvium is bounded by two disconformities resulting from prehistoric and historic arroyo cutting at ca. A.D. 1200-1400 and 1860-1910, respectively. The fill forms a terrace in the axial valleys of major through-flowing streams. This terrace and underlying deposits are continuous and interfinger with sediment in numerous small tributary valleys that head at the base of hillslopes of sparsely vegetated, weakly consolidated bedrock, suggesting that eroded bedrock was an important source of alluvium along with in-channel and other sources. Paleoclimatic and high-resolution paleoflood studies indicate that valley-fill alluviation occured during a long-term decrease in the frequency of large, destructive floods. Aggradation of the valleys ended about A.D. 1880, if not two decades earlier, with the beginning of historic arroyo cutting. This shift from deposition to valley entrenchment near the close of the Little Ice Age generally coincided with the beginning of an episode of the largest floods in the preceding 400-500 yr, which was probably caused by an increased recurrence and intensity of flood-producing El Nin??o events beginning at ca. A.D. 1870.

Geomorphic development and Middle Stone Age archaeology of the Lower Cunene River, Namibia-Angola Border

NASA Astrophysics Data System (ADS)

Nicoll, K.

2010-06-01

During geomorphic reconnaissance of the Lower Cunene River near the reach of Serra Cafema, a significant accumulation of Middle Stone Age artifacts was discovered along the Namibia-Angolan border. The archaeological site is downstream of the Marienfluss-Hartmann Valley and lies along the eastern perimeter of the hyperarid Cunene erg (sandsea). Within the study area, the Cunene River is a bedrock anabranching - mixed bedrock-alluvial anabranching system with a morphology that is strongly controlled by lithology and structure and a hydrology dominated by tropical rainfall in the headwaters. A 5 m high alluvial terrace along the left bank of the perennial river is mantled with a surface lag of cobbles and gravels that includes MSA lithics. More than 30 artifacts are preserved in this open-air context. Finds include quartzite flakes, cores, and Levallois-Mousterian points with varying degrees of edge abrasion and varnish; these appear to be the first Levallois-Mousterian points found in this region of Africa. Since the archaeology of this region is poorly known, these cultural assemblages enable initial correlations across southern Africa. A replicate OSL-SAR date ˜220 kyr provides initial age constraints on a sand preserved within the cobble-boulder terrace fill, and constrains a maximum age for the overlying archaeological assemblage. This is the first MSA site in northern Namibia in direct stratigraphic context with a securely dated unit. The artifact assemblage underscores the importance of riparian corridors in reconstructing hominin behaviours during the Middle Pleistocene, the time frame marked by the first appearance and the dispersal of the modern human species Homo sapiens.

Groundwater controls on river channel pattern

NASA Astrophysics Data System (ADS)

Bätz, Nico; Colombini, Pauline; Cherubini, Paolo; Lane, Stuart N.

2017-04-01

Braided rivers are characterized by high rates of morphological change. However, despite the potential for frequent disturbance, vegetated patches may develop within this system and influence long-term channel dynamics and channel patterns through the "engineering effects" of vegetation. The stabilizing effect of developing vegetation on morphological change has been widely shown by flume experiments and (historic) aerial pictures analysis. Thus, there is a balance between disturbance and stabilization, mediated through vegetation, that may determine the long-term geomorphic and biogeomorphic evolution of the river. It follows that with a change in disturbance frequency relative to the rate of vegetation establishment, a systematic geomorphological shift could occur. Research has addressed how changes in disturbance frequency affect river channel pattern, but has rarely addressed the way in which the stabilizing effects of biogeomorphic succession interact with disturbance frequency to maintain a river in a more dynamic or a less dynamic state. Here, we quantify how the interplay between groundwater access, disturbance frequency and vegetation succession, drive changes in channel pattern. We studied this complex interplay on a transitional gravel-bed river system (braided, wandering, meandering) close to Geneva (Switzerland) - the Allondon River. Dendroecological analysis demonstrate that vegetation growth is driven by groundwater access. Groundwater access conditions the rate of vegetation stabilization at the sub-reach scale and, due to a reduction in flood-related disturbance frequency over the last 50 years, drives a change in channel pattern. Where groundwater is shallower, vegetation encroachment rates were high and as flood-related disturbance decreased, the river has shifted towards a meandering state. Where groundwater was deeper, vegetation growth was limited by water-access and thus vegetation encroachment rates were low. Even though there was a reduction in flood disturbance, it was still sufficient to maintain a wandering/braided state. Thus, it appears that access to groundwater can control river channel pattern through its impact upon the "engineering effects" of vegetation. The results are important for river management as they highlight the non-linearity of developing vegetation in dynamic alluvial floodplains and the importance of considering the wider environmental setting and associated feedbacks between biotic and abiotic river components in defining long-term geomorphological river response.

Morphology and spacing of river meander scrolls

NASA Astrophysics Data System (ADS)

Strick, Robert J. P.; Ashworth, Philip J.; Awcock, Graeme; Lewin, John

2018-06-01

Many of the world's alluvial rivers are characterised by single or multiple channels that are often sinuous and that migrate to produce a mosaicked floodplain landscape of truncated scroll (or point) bars. Surprisingly little is known about the morphology and geometry of scroll bars despite increasing interest from hydrocarbon geoscientists working with ancient large meandering river deposits. This paper uses remote sensing imagery, LiDAR data-sets of meandering scroll bar topography, and global coverage elevation data to quantify scroll bar geometry, anatomy, relief, and spacing. The analysis focuses on preserved scroll bars in the Mississippi River (USA) floodplain but also compares attributes to 19 rivers of different scale and depositional environments from around the world. Analysis of 10 large scroll bars (median area = 25 km2) on the Mississippi shows that the point bar deposits can be categorised into three different geomorphological units of increasing scale: individual 'scrolls', 'depositional packages', and 'point bar complexes'. Scroll heights and curvatures are greatest near the modern channel and at the terminating boundaries of different depositional packages, confirming the importance of the formative main channel on subsequent scroll bar relief and shape. Fourier analysis shows a periodic variation in signal (scroll bar height) with an average period (spacing) of 167 m (range 150-190 m) for the Mississippi point bars. For other rivers, a strong relationship exists between the period of scroll bars and the adjacent primary channel width for a range of rivers from 55 to 2042 mis 50% of the main channel width. The strength of this correlation over nearly two orders of magnitude of channel size indicates a scale independence of scroll bar spacing and suggests a strong link between channel migration and scroll bar construction with apparent regularities despite different flow regimes. This investigation of meandering river dynamics and floodplain patterns shows that it is possible to develop a suite of metrics that describe scroll bar morphology and geometry that can be valuable to geoscientists predicting the heterogeneity of subsurface meandering deposits.

Holocene landscape response to seasonality of storms in the Mojave Desert

USGS Publications Warehouse

Miller, D.M.; Schmidt, K.M.; Mahan, S.A.; McGeehin, J.P.; Owen, L.A.; Barron, J.A.; Lehmkuhl, F.; Lohrer, R.

2010-01-01

New optically stimulated and radiocarbon ages for alluvial fan and lake deposits in the Mojave Desert are presented, which greatly improves the temporal resolution of surface processes. The new Mojave Desert climate-landscape record is particularly detailed for the late Holocene. Evidence from ephemeral lake deposits and landforms indicates times of sustained stream flow during a wet interval of the latter part of the Medieval Warm Period at ca. AD 1290 and during the Little Ice Age at ca. AD 1650. The former lakes postdate megadroughts of the Medieval Warm Period, whereas the latter match the Maunder Minimum of the Little Ice Age. Periods of alluvial fan aggradation across the Mojave Desert are 14-9 cal ka and 6-3 cal ka. This timing largely correlates to times of increased sea-surface temperatures in the Gulf of California and enhanced warm-season monsoons. This correlation suggests that sustained alluvial fan aggradation may be driven by intense summer-season storms. These data suggest that the close proximity of the Mojave Desert to the Pacific Ocean and the Gulf of California promotes a partitioning of landscape-process responses to climate forcings that vary with seasonality of the dominant storms. Cool-season Pacific frontal storms cause river flow, ephemeral lakes, and fan incision, whereas periods of intense warm-season storms cause hillslope erosion and alluvial fan aggradation. The proposed landscape-process partitioning has important implications for hazard mitigation given that climate change may increase sea-surface temperatures in the Gulf of California, which indirectly could increase future alluvial fan aggradation.

Restoring the Mississippi River Basin from the Catchment to the Coast Defines Science and Policy Issues of Ecosystem Services Associated with Alluvial and Coastal Deltaic Floodplains: Soil Conservation, Nutrient Reduction, Carbon Sequestration, and Flood Control

NASA Astrophysics Data System (ADS)

Twilley, R.

2014-12-01

Large river systems are major economic engines that provide national economic wealth in transporting commerce and providing extensive agriculture production, and their coastal deltas are sites of significant ports, energy resources and fisheries. These coupled natural and social systems from the catchment to the coast depend on how national policies manage the river basins that they depend. The fundamental principle of the Mississippi River Basin, as in all basins, is to capitalize on the ability of fertile soil that moves from erosional regions of a large watershed, through downstream regions of the catchment where sediment transport and storage builds extensive floodplains, to the coastal region of deposition where deltas capture sediment and nutrients before exported to the oceans. The fate of soil, and the ability of that soil to do work, supports the goods and services along its path from the catchment to the coast in all large river basin and delta systems. Sediment is the commodity of all large river basin systems that together with the seasonal pulse of floods across the interior of continents provide access to the sea forming the assets that civilization and economic engines have tapped to build national and global wealth. Coastal landscapes represent some of the most altered ecosystems worldwide and often integrate the effects of processes over their entire catchment, requiring systemic solutions to achieve restoration goals from alluvial floodplains upstream to coastal deltaic floodplains downstream. The urgent need for wetland rehabilitation at landscape scales has been initiated through major floodplain reclamation and hydrologic diversions to reconnect the river with wetland processes. But the constraints of sediment delivery and nutrient enrichment represent some critical conflicts in earth surface processes that limit the ability to design 'self sustaining' public work projects; particularly with the challenges of accelerated sea level rise. Only through rethinking how we manage the Mississippi River not only to provide for navigation and flood control, but also as the critical source of sediments to stabilize degrading wetlands, will restoration be realized in a 100-year project cycle.

Active tectonic of the Medlicott Wadia Thrust (Western Himalaya) inferred from morphotectonic analysis

NASA Astrophysics Data System (ADS)

Vignon, V.; Mugnier, J. L.; Replumaz, A.; Vassallo, R.; Ramakrishnan, R.; Srivastava, P.; Malik, M. M.; Jouanne, F.; Carcaillet, J.

2010-12-01

We study the main emergence of the Main Himalayan Thrust (MHT), in the western Himalaya. The MHT is the active Indian/Asian plate boundary and is responsible for M > 8 shallow earthquakes. Its main emergence in west Himalaya occurred along the Medlicott Wadia Thrust (MWT) responsible for the 2005 M 7.6 Balakot earthquake in Pakistan. In the Riasi area, two major rivers, the Chenab and the Anji, have built large fluvial terraces across the MWT. We have mapped the geometry of the terraces and the elevation of the tectonic scarps using kinematic GPS, total station measurements and satellite imagery. The terraces have been dated combining several methods: cosmogenic-nuclide dating (10Be) on boulders constituting the terrace treads, and Optically Stimulated Luminescence (OSL) on fine-grained deposit layers. At the hanging wall of the fault, the Palaeozoic limestone bedrock is deeply incised by Chenab River that formed a series of stepped strath terraces from the present river level up to 350 m above it. We have mapped and measured the relative height of 8 terraces and of their alluvial cover. To estimate the incision rate of the hanging wall, we dated 3 terraces, situated respectively 375 m, 250m and 100m above the present day river bed. The highest terrace has a minimum exposure age of 28 ka. This yield a maximum incision rate of 1,3 cm/yr over the last 28 ka. At the foot wall of the fault, we have mapped 6 terraces deposited above tertiary foreland basin sediment (Siwalik). The most extended terrace, on which the Riasi city is built, forms the top of a more than 40 m thick aggradation sedimentary body, deposited between 16 and 14 ka. A tributary inflowing stream (Nodda River) deposited a steep alluvial fan above the active fault. Nodda River incised since ~4 ka its own deposits and provides a natural trench, revealing three splays of the Riasi thrust. Along the northern splay, Precambrian limestones are thrust over Quaternary sediments. This splay is sealed by Chenab and Nodda deposits and the last motion occurred in a syn-sedimentary context between 35-39 ka. Colluvial wedges related to ~few-meters-displacement paleoearthquakes are preserved within the sedimentary pile. The second splay cuts through the alluvial fan, leading to a scarp that increases towards East reaching more than 37-m-high. The southern splay folds the alluvial fan into a fault-cored anticline, leading to a 34-m-high scarp. These two fault segments are the most recent active structures of the MHT. With a total vertical displacement of ~70 m of a surface dated at around 14 ka the long term slip rate can be estimated between 4.5 and 9 mm/yr. This work confirms that the Medlicott Wadia Thrust is one of the main emergences of the Main Himalayan Thrust in western Himalaya and suggests that it is more active in the Riasi area than in the Balakot area. Considering a 5 centuries seismic gap on a >70 km segment, and a faulting behaviour able to generate several meters co-seismic movement, we may expect a major event in the next few decades in the Riasi region.

Hydrogeologic framework and groundwater/surface-water interactions of the Chehalis River basin, Washington

USGS Publications Warehouse

Gendaszek, Andrew S.

2011-01-01

The Chehalis River has the largest drainage basin of any river entirely contained within the State of Washington with a watershed of approximately 2,700 mi2 and has correspondingly diverse geology and land use. Demands for water resources have prompted the local citizens and governments of the Chehalis River basin to coordinate with Federal, State and Tribal agencies through the Chehalis Basin Partnership to develop a long-term watershed management plan. The recognition of the interdependence of groundwater and surface-water resources of the Chehalis River basin became the impetus for this study, the purpose of which is to describe the hydrogeologic framework and groundwater/surface-water interactions of the Chehalis River basin. Surficial geologic maps and 372 drillers' lithostratigraphic logs were used to generalize the basin-wide hydrogeologic framework. Five hydrogeologic units that include aquifers within unconsolidated glacial and alluvial sediments separated by discontinuous confining units were identified. These five units are bounded by a low permeability unit comprised of Tertiary bedrock. A water table map, and generalized groundwater-flow directions in the surficial aquifers, were delineated from water levels measured in wells between July and September 2009. Groundwater generally follows landsurface-topography from the uplands to the alluvial valley of the Chehalis River. Groundwater gradients are highest in tributary valleys such as the Newaukum River valley (approximately 23 cubic feet per mile), relatively flat in the central Chehalis River valley (approximately 6 cubic feet per mile), and become tidally influenced near the outlet of the Chehalis River to Grays Harbor. The dynamic interaction between groundwater and surface-water was observed through the synoptic streamflow measurements, termed a seepage run, made during August 2010, and monitoring of water levels in wells during the 2010 Water Year. The seepage run revealed an overall gain of 56.8 ± 23.7 cubic feet per second over 32.8 river miles (1.7 cubic feet per second per mile), and alternating gains and losses of streamflow ranging from -48.3 to 30.9 cubic feet per second per mile, which became more pronounced on the Chehalis River downstream of Grand Mound. However, most gains and losses were within measurement error. Groundwater levels measured in wells in unconsolidated sediments fluctuated with changes in stream stage, often within several hours. These fluctuations were set by precipitation events in the upper Chehalis River basin and tides of the Pacific Ocean in the lower Chehalis River basin.±

Bed-material entrainment potential, Roaring Fork River at Basalt, Colorado

USGS Publications Warehouse

Elliott, John G.

2002-01-01

The Roaring Fork River at Basalt, Colorado, has a frequently mobile streambed composed of gravel, cobbles, and boulders. Recent urban and highway development on the flood plain, earlier attempts to realign and confine the channel, and flow obstructions such as bridge openings and piers have altered the hydrology, hydraulics, sediment transport, and sediment deposition areas of the Roaring Fork. Entrainment and deposition of coarse sediment on the streambed and in large alluvial bars have reduced the flood-conveying capacity of the river. Previous engineering studies have identified flood-prone areas and hazards related to inundation and high streamflow velocity, but those studies have not evaluated the potential response of the channel to discharges that entrain the coarse streambed. This study builds upon the results of earlier flood studies and identifies some potential areas of concern associated with bed-material entrainment. Cross-section surveys and simulated water-surface elevations from a previously run HEC?RAS model were used to calculate the boundary shear stress on the mean streambed, in the thalweg, and on the tops of adjacent alluvial bars for four reference streamflows. Sediment-size characteristics were determined for surficial material on the streambed, on large alluvial bars, and on a streambank. The median particle size (d50) for the streambed samples was 165 millimeters and for the alluvial bars and bank samples was 107 millimeters. Shear stresses generated by the 10-, 50-, and 100-year floods, and by a more common flow that just inundated most of the alluvial bars in the study reach were calculated at 14 of the cross sections used in the Roaring Fork River HEC?RAS model. The Shields equation was used with a Shields parameter of 0.030 to estimate the critical shear stress for entrainment of the median sediment particle size on the mean streambed, in the thalweg, and on adjacent alluvial bar surfaces at the 14 cross sections. Sediment-entrainment potential for a specific geomorphic surface was expressed as the ratio of the flood-generated boundary shear stress to the critical shear stress (to/tc) with respect to two threshold conditions. The partial entrainment threshold (to/tc=1) is the condition where the mean boundary shear stress (to) equals the critical shear stress for the median particle size (tc) at that cross section. At this threshold discharge, the d50 particle size becomes entrained, but movement of d50-size particles may be limited to a few individual particles or in a small area of the streambed surface. The complete entrainment threshold (to/tc=2) is the condition where to is twice the critical shear stress for the median particle size, the condition where complete or widespread mobilization of the d50 particle-size fraction is anticipated. Entrainment potential for a specific reference streamflow varied greatly in the downstream direction. At some cross sections, the bed or bar material was mobile, whereas at other cross sections, the bed or bar material was immobile for the same discharge. The significance of downstream variability is that sediment entrained at one cross section may be transported into, but not through, a cross section farther downstream, a situation resulting in sediment deposition and possibly progressive aggradation and loss of channel conveyance. Little or no sediment in the d50-size range is likely to be entrained or transported through much of the study reach by the bar-inundating streamflow. However, the entrainment potential at this discharge increases abruptly to more than twice the critical value, then decreases abruptly, at a series of cross sections located downstream from the Emma and Midland Avenue Bridges. Median particle-size sediment is mobile at most cross sections in the study reach during the 10-year flood; however, the bed material is immobile at cross sections just upstream from the Upper Bypass and Midland Avenue Bridges. A similar s

Recalibration of a ground-water flow model of the Mississippi River Valley alluvial aquifer of northeastern Arkansas, 1918-1998, with simulations of water levels caused by projected ground-water withdrawals through 2049

USGS Publications Warehouse

Reed, Thomas B.

2003-01-01

A digital model of the Mississippi River Valley alluvial aquifer in eastern Arkansas was used to simulate ground-water flow for the period from 1918 to 2049. The model results were used to evaluate effects on water levels caused by demand for ground water from the alluvial aquifer, which has increased steadily for the last 40 years. The model results showed that water currently (1998) is being withdrawn from the aquifer at rates greater than what can be sustained for the long term. The saturated thickness of the alluvial aquifer has been reduced in some areas resulting in dry wells, degraded water quality, decreased water availability, increased pumping costs, and lower well yields. The model simulated the aquifer from a line just north of the Arkansas-Missouri border to south of the Arkansas River and on the east from the Mississippi River westward to the less permeable geologic units of Paleozoic age. The model consists of 2 layers, a grid of 184 rows by 156 columns, and comprises 14,118 active cells each measuring 1 mile on a side. It simulates time periods from 1918 to 1998 along with further time periods to 2049 testing different pumping scenarios. Model flux boundary conditions were specified for rivers, general head boundaries along parts of the western side of the model and parts of Crowleys Ridge, and a specified head boundary across the aquifer further north in Missouri. Model calibration was conducted for observed water levels for the years 1972, 1982, 1992, and 1998. The average absolute residual was 4.69 feet and the root-mean square error was 6.04 feet for the hydraulic head observations for 1998. Hydraulic-conductivity values obtained during the calibration process were 230 feet per day for the upper layer and ranged from 230 to 730 feet per day for the lower layer with the maximum mean for the combined aquifer of 480 feet per day. Specific yield values were 0.30 throughout the model and specific storage values were 0.000001 inverse-feet throughout the model. Areally specified recharge rates ranged from 0 to about 30 inches and total recharge increased from 1972 to 1998 by a factor of about four. Water levels caused by projected ground-water withdrawals were simulated using the calibrated model. Simulations represented a period of 50 years into the future in three scenarios with either unchanged pumpage, pumpage increased by historic trends, or pumpage increased by historic trends except in two areas of the Grand Prairie. If pumping remains at 1997 rates, this produces extreme water-level declines (areas where model cells have gone dry or where the water level in the aquifer is equal to or less than the original saturated thickness, assuming confined conditions in the aquifer everywhere in the formation in predevelopment times) in the aquifer in two areas of the aquifer (one in the Grand Prairie area between the Arkansas and White Rivers and the other west of Crowleys Ridge along the Cache River) with about 400 square miles going dry. Increasing the pumping rates to that which would be projected using historic data led to increased extreme water-level declines in both areas with about 1,300 square miles going dry. Declines in both scenarios generally occurred most rapidly between 2009 and 2019. Reducing the pumping rates to 90 percent of that used for projected historic rates in areas between the Arkansas and White Rivers relating to two diversion projects of the U.S. Army Corps of Engineers and other agencies did little to decrease the extreme water-level declines. However, these pumpage reductions are small (amounting to about 16 percent of the reductions that could result from implementation of these diversion projects).

Groundwater components in the alluvial aquifer of the alpine Rhone River valley, Bois de Finges area, Wallis Canton, Switzerland

NASA Astrophysics Data System (ADS)

Schürch, Marc; Vuataz, François-D.

2000-09-01

Source, type, and quantity of various components of groundwater, as well as their spatial and temporal variations were determined by different hydrochemical methods in the alluvial aquifer of the upper Rhone River valley, Bois de Finges, Wallis Canton, Switzerland. The methods used are hydrochemical modeling, stable-isotope analysis, and chemical analysis of surface water and groundwater. Sampling during high- and low-water periods determined the spatial distribution of the water chemistry, whereas monthly sampling over three years provided a basis for understanding seasonal variability. The physico-chemical parameters of the groundwater have spatial and seasonal variations. The groundwater chemical composition of the Rhone alluvial aquifer indicates a mixing of weakly mineralized Rhone River water and SO4-rich water entering from the south side of the valley. Temporal changes in groundwater chemistry and in groundwater levels reflect the seasonal variations of the different contributors to groundwater recharge. The Rhone River recharges the alluvial aquifer only during the summer high-water period. Résumé. Origine, type et quantité de nombreux composants d'eau de l'aquifère alluvial dans la vallée supérieure du Rhône, Bois de Finges, Valais, Suisse, ainsi que leurs variations spatiales et temporelles ont été déterminés par différentes méthodes hydrochimiques. Les méthodes utilisées sont la modélisation hydrochimique, les isotopes stables, ainsi que l'échantillonnage en période de hautes eaux et de basses eaux pour étudier la distribution spatiale de la composition chimique, alors qu'un échantillonnage mensuel pendant trois ans sert à comprendre les processus de la variabilité saisonnière. Les paramètres physico-chimiques des eaux souterraines montrent des variations spatiales et saisonnières. La composition chimique de l'aquifère alluvial du Rhône indique un mélange entre une eau peu minéralisée venant du Rhône et une eau sulfatée s'écoulant du versant sud. La modification temporelle des paramètres chimiques des eaux souterraines et de la piézométrie reflètent les variations saisonnières des apports d'eau de la nappe souterraine. En période de hautes eaux durant l'été, seul le Rhône recharge l'aquifère alluvial. Resumen. Se ha determinado el origen, tipo y cantidad de diversos elementos de las aguas subterráneas en el acuífero aluvial del valle superior del río Ródano (Bois de Finges, Cantón de Wallis, Suiza), así como sus variaciones espaciales y temporales, mediante métodos hidroquímicos. Entre las herramientas utilizadas, se incluye la modelación hidroquímica, el análisis de isótopos estables y el análisis químico de aguas superficiales y subterráneas. El muestreo en épocas de estiaje y lluvias sirvió para determinar la distribución espacial de la química del agua, mientras que la variabilidad estacional fue caracterizada por medio de muestreos mensuales durante un período de tres años. Los parámetros físicoquímicos de las aguas subterráneas muestran variaciones espaciales y estacionales. La composición química de las aguas subterráneas del acuífero aluvial del río Ródano indica que hay mezcla entre las aguas débilmente mineralizadas del río y las aguas cargadas en sulfato (SO4-2) que proceden de la parte meridional de valle. Los cambios temporales en la química de las aguas subterráneas y en los niveles piezométricos reflejan las variaciones estacionales de las diferentes contribuciones de la recarga. El río Ródano recarga al acuífero aluvial únicamente durante el período estival, cuando el caudal es elevado.

Sand transport, shear stress, and the building of a delta

NASA Astrophysics Data System (ADS)

Wagner, W.; Miller, K. L.; Hiatt, M. R.; Mohrig, D. C.

2017-12-01

River deltas distribute sediment to the coastal sea through a complex branching network of channels; however, the routing and storage of this sediment in and through the delta is poorly understood. We present results from field studies of the sediment and water transport through the branching Wax Lake Delta on the coast of Louisiana. Two channels studied, Main Pass and East Pass, maintain a near-equal total partitioning of flow and sediment. However, East Pass is narrower and has higher river velocities, lower tidal velocity fluctuations, less alluvial bed cover, and more sediment flux per unit width than Main Pass. We connect these differences to small differences in the geometry of the two channels and feedbacks between these differences. We link trends in measured sediment deposits to both measured and modeled shear velocities in Wax Lake Delta's channels and open water `islands' to understand how hydrologic processes shaped the sedimentary architecture of the delta. These connections define the sediment transport and deposition regimes in the WLD. We extend the results herein to suggest that the relationships between the available sediment and shear stress determines the basic planform of the Wax Lake Delta and cross-sectional geometries of its channels.

The evolving landscape and climate of western Flores: an environmental context for the archaeological site of Liang Bua.

PubMed

Westaway, K E; Roberts, R G; Sutikna, T; Morwood, M J; Drysdale, R; Zhao, J-x; Chivas, A R

2009-11-01

The rapidly changing landscape of the eastern Indonesian archipelago has evolved at a pace dictated by its tropical climate and its geological and tectonic history. This has produced accelerated karstification, flights of alluvial terraces, and complex, multi-level cave systems. These cave systems sometimes contain a wealth of archaeological evidence, such as the almost complete skeleton of Homo floresiensis found at the site of Liang Bua in western Flores, but this information can only be understood in the context of the geomorphic history of the cave, and the more general geological, tectonic, and environmental histories of the river valley and region. Thus, a reconstruction of the landscape history of the Wae Racang valley using speleothems, geological structure, tectonic uplift, karst, cave, and terrace development, provides the necessary evidence to determine the formation, age, evolution, and influences on the site. This evidence suggests that Liang Bua was formed as two subterranean chambers approximately 600ka, but could not be occupied until approximately 190ka when the Wae Racang wandered to the southern side of the valley, exposing the chamber and depositing alluvial deposits containing artifacts. During the next approximately 190k.yr., the chambers coalesced and evolved into a multi-level and interconnected cave that was subjected to channel erosion and pooling events by the development of sinkholes. The domed morphology of the front chamber accumulated deep sediments containing well stratified archaeological and faunal remains, but ponded water in the chamber further prevented hominin use of the cave until approximately 100ka. These chambers were periodically influenced by river inundation and volcanic activity, whereas the area outside the cave was greatly influenced by glacial phases, which changed humid forest environments into grassland environments. This combined evidence has important implications for the archaeological interpretation of the site.

Inverse geochemical modeling of groundwater evolution with emphasis on arsenic in the Mississippi River Valley alluvial aquifer, Arkansas (USA)

USGS Publications Warehouse

Sharif, M.U.; Davis, R.K.; Steele, K.F.; Kim, B.; Kresse, T.M.; Fazio, J.A.

2008-01-01

Inverse geochemical modeling (PHREEQC) was used to identify the evolution of groundwater with emphasis on arsenic (As) release under reducing conditions in the shallow (25-30 m) Mississippi River Valley Alluvial aquifer, Arkansas, USA. The modeling was based on flow paths defined by high-precision (??2 cm) water level contour map; X-ray diffraction (XRD), scanning electron microscopic (SEM), and chemical analysis of boring-sediments for minerals; and detailed chemical analysis of groundwater along the flow paths. Potential phases were constrained using general trends in chemical analyses data of groundwater and sediments, and saturation indices data (MINTEQA2) of minerals in groundwater. Modeling results show that calcite, halite, fluorite, Fe oxyhydroxide, organic matter, H2S (gas) were dissolving with mole transfers of 1.40E - 03, 2.13E - 04, 4.15E - 06, 1.25E + 01, 3.11, and 9.34, respectively along the dominant flow line. Along the same flow line, FeS, siderite, and vivianite were precipitating with mole transfers of 9.34, 3.11, and 2.64E - 07, respectively. Cation exchange reactions of Ca2+ (4.93E - 04 mol) for Na+ (2.51E - 04 mol) on exchange sites occurred along the dominant flow line. Gypsum dissolution reactions were dominant over calcite dissolution in some of the flow lines due to the common ion effect. The concentration of As in groundwater ranged from <0.5 to 77 ??g/L. Twenty percent total As was complexed with Fe and Mn oxyhydroxides. The redox environment, chemical data of sediments and groundwater, and the results of inverse geochemical modeling indicate that reductive dissolution of Fe oxyhydroxide is the dominant process of As release in the groundwater. The relative rate of reduction of Fe oxyhydroxide over SO42 - with co-precipitation of As into sulfide is the limiting factor controlling dissolved As in groundwater. ?? 2007 Elsevier B.V. All rights reserved.

Quantity and quality of ground-water discharge to the South Platte River, Denver to Fort Lupton, Colorado, August 1992 through July 1993

USGS Publications Warehouse

McMahon, P.B.; Lull, K.J.; Dennehy, K.F.; Collins, J.A.

1995-01-01

Water-quality studies conducted by the Metro Wastewater Reclamation District have indicated that during low flow in segments of the South Platte River between Denver and Fort Lupton, concentrations of dissolved oxygen are less than minimum concen- trations set by the State of Colorado. Low dissolved-oxygen concentrations are observed in two reaches of the river-they are about 3.3 to 6.4 miles and 17 to 25 miles downstream from the Metro Waste- water Reclamation District effluent outfalls. Concentrations of dissolved oxygen recover between these two reaches. Studies conducted by the U.S. Geological Survey have indicated that ground-water discharge to the river may contribute to these low dissolved-oxygen concentrations. As a result, an assessment was made of the quantity and quality of ground-water discharge to the South Platte River from Denver to Fort Lupton. Measurements of surface- water and ground-water discharge and collections of surface water and ground water for water-quality analyses were made from August 1992 through January 1993 and in May and July 1993. The quantity of ground-water discharge to the South Platte River was determined indirectly by mass balance of surface-water inflows and outflows and directly by instantaneous measurements of ground-water discharge across the sediment/water interface in the river channel. The quality of surface water and ground water was determined by sampling and analysis of water from the river and monitoring wells screened in the alluvial aquifer adjacent to the river and by sampling and analysis of water from piezometers screened in sediments underlying the river channel. The ground-water flow system was subdivided into a large-area and a small-area flow system. The precise boundaries of the two flow systems are not known. However, the large-area flow system is considered to incorporate all alluvial sediments in hydrologic connection with the South Platte River. The small- area flow system is considered to incorporate the alluvial aquifer in the vicinity of the river. Flow-path lengths in the large-area flow system were considered to be on the order of hundreds of feet to more than a mile, whereas in the small-area flow system, they were considered to be on the order of feet to hundreds of feet. Mass-balance estimates of incremental ground-water discharge from the large- area flow system ranged from -27 to 17 cubic feet per second per mile in three reaches of the river; the median rate was 4.6 cubic feet per second per mile. The median percentage of surface-water discharge derived from ground-water discharge in the river reaches studied was 13 percent. Instantaneous measurements of ground-water discharge from the small-area flow system ranged from -1,360 to 1,000 cubic feet per second per mile, with a median value of -5.8 cubic feet per second per mile. Hourly measurements of discharge from the small-area flow system indicated that the high rates of discharge were transient and may have been caused by daily fluctuations in river stage due to changing effluent-discharge rates from the Metro Wastewater Reclamation District treatment plant. Higher river stages caused surface water to infiltrate bed sediments underlying the river channel, and lower river stages allowed ground water to discharge into the river. Although stage changes apparently cycled large quantities of water in and out of the small- area flow system, the process probably provided no net gain or loss of water to the river. In general, mass balance and instantaneous measurements of ground-water discharge indicated that the ground- water flow system in the vicinity of the river consisted of a large-area flow system that provided a net addition of water to the river and a small- area flow system that cycled water in and out of the riverbed sediments, but provided no net addition of water to the river. The small-area flow system was superimposed on the large-area flow system. The median values of pH and dissolved oxygen

Possible Links Among Iron Reduction, Silicate Weathering, and Arsenic Mobility in the Mississippi River Alluvial Aquifer in Louisiana

NASA Astrophysics Data System (ADS)

Borrok, D. M.; Lenz, R. M.; Jennings, J. E.; Gentry, M. L.; Vinson, D. S.

2017-12-01

The Lower Mississippi River Alluvial Aquifer (LMRAA) is a critical groundwater resource for Arkansas, Mississippi, and Louisiana. Part of the aquifer in Louisiana contains waters rich in Na, HCO3, Fe, and As. We hypothesize that CO2 generated from dissimilatory iron reduction (DIR) within the aquifer acts to weather Na-bearing silicates, contributing Na and HCO3, which may influence the mobility of As. We examined the geochemistry of the aquifer using historical and new data collected from the Louisiana Department of Environmental Quality (LDEQ). Major and trace element data were collected from about 25 wells in the LMRAA in Louisiana every three years from 2001-2016. Samples collected in 2016 were additionally analyzed for water isotopes and the δ13C of dissolved inorganic carbon (DIC). Results suggest that groundwater in the LMRAA can be broken into two broad categories, (1) water with a molar Na/Cl ratio near 1 and/or high salinity, and (2) water with excess Na (i.e., the molar concentration of Na is greater than that of Cl) that is often higher in alkalinity (up to 616 mg/L as CaCO3), Fe (up to 21 mg/L), and sometimes As (up to 67 µg/L). Concentrations of dissolved Fe were found to correlate, at least weakly, with alkalinity and Na excess. Six of the approximately 25 wells historically sampled consistently had concentrations of As >10 µg/L. These locations generally correspond with groundwater characterized by higher Fe, alkalinity, and Na-excess. Initial results for δD and δ18O suggest that more isotopically depleted waters are sourced from the Mississippi River, whereas local precipitation recharges the aquifer farther from the river (δ18O ranged from -7.5‰ to -3.5‰). Part of the δ13C-DIC variation (-17.4‰ to -10.6‰) is consistent with pH modification (6.5-7.7) along differing horizontal and vertical flow paths in the aquifer. This geochemistry appears to be controlled in part by geology. Areas nearer to the current Mississippi River where alluvial valley train deposits are absent have thicker layers of Holocene-age clays, which may provide more labile organic matter for DIR, leading to higher concentrations of dissolved Fe in groundwater. Overall, these data are consistent with the hypothesized linkages among DIR, silicate weathering, and high (> 10µg/L) concentrations of As in parts of the LMRAA.

Hydrogeologic framework and groundwater/surface-water interactions of the South Fork Nooksack River Basin, northwestern Washington

USGS Publications Warehouse

Gendaszek, Andrew S.

2014-01-01

A hydrogeologic framework of the South Fork (SF) Nooksack River Basin in northwestern Washington was developed and hydrologic data were collected to characterize the groundwater-flow system and its interaction with surface‑water features. In addition to domestic, agricultural, and commercial uses of groundwater within the SF Nooksack River Basin, groundwater has the potential to provide ecological benefits by maintaining late-summer streamflows and buffering stream temperatures. Cold-water refugia, created and maintained in part by groundwater, have been identified by water-resource managers as key elements to restore the health and viability of threatened salmonids in the SF Nooksack River. The SF Nooksack River drains a 183-square mile area of the North Cascades and the Puget Lowland underlain by unconsolidated glacial and alluvial sediments deposited over older sedimentary, metamorphic, and igneous bedrock. The primary aquifer that interacts with the SF Nooksack River was mapped within unconsolidated glacial outwash and alluvial sediment. The lower extent of this unit is bounded by bedrock and fine-grained, poorly sorted unconsolidated glaciomarine and glaciolacustrine sediments. In places, these deposits overlie and confine an aquifer within older glacial sediments. The extent and thickness of the hydrogeologic units were assembled from mapped geologic units and lithostratigraphic logs of field-inventoried wells. Generalized groundwater-flow directions within the surficial aquifer were interpreted from groundwater levels measured in August 2012; and groundwater seepage gains and losses to the SF Nooksack River were calculated from synoptic streamflow measurements made in the SF Nooksack River and its tributaries in September 2012. A subset of the field-inventoried wells was measured at a monthly interval to determine seasonal fluctuations in groundwater levels during water year 2013. Taken together, these data provide the foundation for a future groundwater-flow model of the SF Nooksack River Basin that may be used to investigate the potential effects of future climate change, land use, and groundwater pumping on water resources in the study area. Site-specific hydrologic data, including time series of longitudinal temperature profiles measured with a fiber-optic distributed temperature sensor and continuous monitoring of stream stage and water levels measured in wells in adjacent wetlands and aquifers, also were measured to characterize the interaction among the SF Nooksack River, surficial aquifers, and riparian wetlands.

Rio Grande valley Colorado new Mexico and Texas

USGS Publications Warehouse

Ellis, Sherman R.; Levings, Gary W.; Carter, Lisa F.; Richey, Steven F.; Radell, Mary Jo

1993-01-01

Two structural settings are found in the study unit: alluvial basins and bedrock basins. The alluvial basins can have through-flowing surface water or be closed basins. The discussion of streamflow and water quality for the surface-water system is based on four river reaches for the 750 miles of the main stem. the quality of the ground water is affected by both natural process and human activities and by nonpoint and point sources. Nonpoint sources for surface water include agriculture, hydromodification, and mining operations; point sources are mainly discharge from wastewater treatment plants. Nonpoint sources for ground water include agriculture and septic tanks and cesspools; point sources include leaking underground storage tanks, unlined or manure-lined holding ponds used for disposal of dairy wastes, landfills, and mining operations.

Variable scale channel avulsion history using fan architecture and stratigraphy, and sediment provenance of Sutlej-Yamuna fans in northwest Gangetic plains during Late Quaternary

NASA Astrophysics Data System (ADS)

Singh, Ajit; Gupta, Sanjeev; Sinha, Rajiv; Densmore, Alexander; Buylaert, Jan-Pieter; Carter, Andrew; Van-Dijk, Wout M.; Joshi, Suneel; Nayak, Nibedita; Mason, Philippa J.; Kumar, Dewashish; Mondal, Setbandhu; Murray, Andrew; Rai, Shiv P.; Shekhar, Shashank

2016-04-01

Channel avulsion during fan development controls distribution and deposition of channel sandbodies and hence alluvial architecture of a fan system. Variable scale spatio-temporal information of fluvial responses to past climate changes is stored in these channel sandbodies. Further these channel sandbodies form fluvial aquifers in alluvial fans and therefore understanding of alluvial architecture and stratigraphy of a fan is crucial for development of groundwater management strategies. In this study we used multiple approaches to map subsurface fluvial aquifer architecture and alluvial stratigraphy, and to estimate sediment provenance using U-Pb dating of detrital zircon grains of Sutlej-Yamuna fan system in northwest India. Satellite imagery based geomorphic mapping shows two large fan system with interfan area. The fan surfaces show presence of major and minor paleochannels. 2D resistivity tomography along several transects across fan surfaces shows distinct layers with contrasting resistivity values. These geo-electric facies corresponds to presence of channel sandbodies beneath surface signature of paleochannels and finer floodplain deposits useful to demarcate lateral extent of subsurface channel sandbodies. A more detailed subsurface stratigraphy using ~50m deep sediment cores and their luminescence ages from across fan surface shows presence of multi-storey sandbodies (MSB) separated by floodplain fines. Within the MSB, individual channel deposits are identified by presence of channel scour surfaces located at coarse sand overlying fine sand layer. Depositional ages of MSB's ranges from ~81 ka (late MIS5) to ~15 ka (MIS2) with major depositional break during MIS3 in parts of the fans. Sediment aggradation rate varies laterally across fan surface as well as vertically down the depth with an average rate of 0.54 mm/year. Fluvial channel persistence for studied time interval (about last 81 ka BP) shows major depositional breaks (and possible incision) at ~41 ka (mid MIS3) and ~31 ka (late MIS3). U-Pb age patterns of detrital zircon grains from cores located at paleochannels on the fan system show prominent age peaks at ~480 Ma and ~1800 Ma that respectively corresponds to modern Sutlej and Yamuna rivers. Luminescence ages of these samples suggest that major channel activity of Sutlej river at its fan system ceased around ~15 ka (post last-glacial maxima) and thereafter it avulsed to its modern course. Our surface study results clearly show that alluvial fan system have well developed longitudinal channel sandbodies that may or may not have surface expression in the form of paleochannel and/or longitudinal ridges. However our geophysical studies show that such channel sandbodies can be delineated in shallow surface on the basis of characteristic resistivity values. The subsurface stratigraphy results show development of MSB possibly due to series of small scale (intravalley) avulsion punctuated by large scale (intervalley) avulsion across the fan surface. Our provenance studies clearly identifies two major large scale channel avulsions of Sutlej and Yamuna rivers. Our study has importance for groundwater management policies in this water-stressed agricultural hotspot of India. Thus, understanding the variability in sand body stratigraphy, channel avulsion history, and aggradation rates is important for understanding aquifer geometry of alluvial fan system.

Metagenomic analyses of the late Pleistocene permafrost - additional tools for reconstruction of environmental conditions

NASA Astrophysics Data System (ADS)

Rivkina, Elizaveta; Petrovskaya, Lada; Vishnivetskaya, Tatiana; Krivushin, Kirill; Shmakova, Lyubov; Tutukina, Maria; Meyers, Arthur; Kondrashov, Fyodor

2016-04-01

A comparative analysis of the metagenomes from two 30 000-year-old permafrost samples, one of lake-alluvial origin and the other from late Pleistocene Ice Complex sediments, revealed significant differences within microbial communities. The late Pleistocene Ice Complex sediments (which have been characterized by the absence of methane with lower values of redox potential and Fe2+ content) showed a low abundance of methanogenic archaea and enzymes from both the carbon and nitrogen cycles, but a higher abundance of enzymes associated with the sulfur cycle. The metagenomic and geochemical analyses described in the paper provide evidence that the formation of the sampled late Pleistocene Ice Complex sediments likely took place under much more aerobic conditions than lake-alluvial sediments.

Estimation of alluvial-fill thickness in the Mimbres ground-water basin, New Mexico, from interpretation of isostatic residual gravity anomalies

USGS Publications Warehouse

Heywood, Charles E.

2002-01-01

The geologic structure of the Mimbres ground-water basin in southwest New Mexico is characterized by north- and northwest-trending structural subbasins. Sedimentation of Miocene and Pliocene age has filled and obscured the boundaries of these subbasins and formed poten- tially productive aquifers of varied thickness. The location and depth of the subbasins can be esti- mated from analysis of isostatic residual gravity anomalies. Density contrasts of various basement lithologies generate complex regional gravity trends, which are convolved with the gravity signal from the Miocene and Pliocene alluvial fill. An iterative scheme was used to separate these regional gravity trends from the alluvial-fill grav- ity signal, which was inverted with estimated depth-density relations to compute the thickness of the alluvial fill at 1-kilometer spacing. The thickness estimates were constrained by explor- atory drill-hole information, interpreted seismic- refraction profiles, and location of bedrock lithol- ogy from surficial geologic mapping. The result- ing map of alluvial-fill thickness suggests large areas of thin alluvium that separate deep structural subbasins.

Deep soil dynamics of floodplain carbon in the Central Valley of California

NASA Astrophysics Data System (ADS)

Steger, Kristin; Kim, Amy T.; Viers, Joshua H.; Fiener, Peter; Smart, David R.

2017-04-01

Active floodplains can putatively store large amounts of organic carbon (SOC) in subsoils originating from catchment erosion processes with subsequent floodplain deposition. Changes in catchment land use patterns and river management to optimize agricultural use of the floodplain or to restore the floodplain back to natural systems may alter SOC stocks in these soils. Our study focussed on the assessment of SOC pools associated with alluvial floodplain soils converting from conventional arable use to restored flooding and floodplain vegetation. We evaluated depth-dependent SOC contents using 21 drillings down to 3m and 10 drillings down to 7m along a transect through a floodplain area of the lower Cosumnes River, a non-constrained tributary to the Sacramento - San Joaquin Delta in California. In general, our data underline the importance of carbon stocks in subsoils >1m, which represent up to 19 and 6% of SOC stocks at the different sampling locations accounting for drillings down to 3 and 7m, respectively. All of our sampling sites revealed a SOC-rich buried A horizon between 70 and 130cm with SOC concentrations between 11 and 17g/kg, representative of the functioning floodplain system pre-disturbance. Radiocarbon dating showed that the 14C age in the buried horizon was younger than in the overlaying soils, indicating a substantial sedimentation phase with sediments of low SOC concentrations and higher carbon age. This sedimentation phase was probably associated with the huge upstream sediment production resulting from the hydraulic gold mining at the Cosumnes River starting around 1860. Apart from larger SOC contents in the buried horizon compared to the recent topsoil, its 13C and 15N isotopic signature also differed suggesting a change in long-term input of plant organic matter as well as different fertilization regimes during the agricultural use of the area from approx. 1890 onwards. In summary, deep alluvial soils in floodplains store large amounts of SOC not yet accounted for in global models. Intensive agricultural use of these floodplains often combined with river regulation and embanking of floodplain areas may lead to a slow but continuous release of the buried SOC to the atmosphere. However, restoration of floodplains may promote the stabilization of alluvial SOC in floodplains and hence contribute to more sustainable soils.

Precambrian fluvial deposits: Enigmatic palaeohydrological data from the c. 2 1.9 Ga Waterberg Group, South Africa

NASA Astrophysics Data System (ADS)

Eriksson, Patrick G.; Bumby, Adam J.; Brümer, Jacobus J.; van der Neut, Markus

2006-08-01

Precambrian fluvial systems, lacking the influence of rooted vegetation, probably were characterised by flashy surface runoff, low bank stability, broad channels with abundant bedload, and faster rates of channel migration; consequently, a braided fluvial style is generally accepted. Pre-vegetational braided river systems, active under highly variable palaeoclimatic conditions, may have been more widespread than are modern, ephemeral dry-land braided systems. Aeolian deflation of fine fluvial detritus does not appear to have been prevalent. With the onset of large cratons by the Neoarchaean-Palaeoproterozoic, very large, perennial braided river systems became typical. The c. 2.06-1.88 Ga Waterberg Group, preserved within a Main and a smaller Middelburg basin on the Kaapvaal craton, was deposited largely by alluvial/braided-fluvial and subordinate palaeo-desert environments, within fault-bounded, possibly pull-apart type depositories. Palaeohydrological data obtained from earlier work in the Middelburg basin (Wilgerivier Formation) are compared to such data derived from the correlated Blouberg Formation, situated along the NE margin of the Main basin. Within the preserved Blouberg depository, palaeohydrological parameters estimated from clast size and cross-bed set thickness data, exhibit rational changes in their values, either in a down-palaeocurrent direction, or from inferred basin margin to palaeo-basin centre. In both the Wilgerivier and Blouberg Formations, calculated palaeoslope values (derived from two separate formulae) plot within the gap separating typical alluvial fan gradients from those which characterise rivers (cf. [Blair, T.C., McPherson, J.G., 1994. Alluvial fans and their natural distinction from rivers based on morphology, hydraulic processes, sedimentary processes, and facies assemblages. J. Sediment. Res. A64, 450-489.]). Although it may be argued that such data support possibly unique fluvial styles within the Precambrian, perhaps related to a combination of major global-scale tectono-thermal and atmospheric-palaeoclimatic events, a simpler explanation of these apparently enigmatic palaeoslope values may be pertinent. Of the two possible palaeohydrological formulae for calculating palaeoslope, one provides results close to typical fluvial gradients; the other formula relies on preserved channel-width data. We suggest that the latter will not be reliable due to problematic preservation of original channel-widths within an active braided fluvial system. We thus find no unequivocal support for a unique fluvial style for the Precambrian, beyond that generally accepted for that period and discussed briefly in the first paragraph.

Facies architecture and paleohydrology of a synrift succession in the Early Cretaceous Choyr Basin, southeastern Mongolia

USGS Publications Warehouse

Ito, M.; Matsukawa, M.; Saito, T.; Nichols, D.J.

2006-01-01

The Choyr Basin is one of several Early Cretaceous rift basins in southwestern Mongolia that developed in specific regions between north-south trending fold-and-thrust belts. The eastern margin of the basin is defined by high-angle normal and/or strike-slip faults that trend north-to-south and northeast-to-southwest and by the overall geometry of the basin, which is interpreted to be a half graben. The sedimentary succession of the Choyr Basin documents one of the various types of tectono-sedimentary processes that were active in the rift basins of East Asia during Early Cretaceous time. The sedimentary infill of the Choyr Basin is newly defined as the Khalzan Uul and Khuren Dukh formations based on detailed mapping of lateral and vertical variations in component lithofacies assemblages. These two formations are heterotopic deposits and constitute a third-order fluvio-lacustrine sequence that can be divided into transgressive and highstand systems tracts. The lower part of the transgressive systems tract (TST) is characterized by sandy alluvial-fan and braided-river systems on the hanging wall along the western basin margin, and by a gravelly alluvial-fan system on the footwall along the eastern basin margin. The alluvial-fan and braided-river deposits along the western basin margin are fossiliferous and are interpreted to have developed in association with a perennial fluvial system. In contrast, alluvial-fan deposits along the eastern basin margin do not contain any distinct faunas or floras and are interpreted to have been influenced by a high-discharge ephemeral fluvial system associated with fluctuations in wetting and drying paleohydrologic processes. The lower part of the TST deposit fines upward to siltstone-dominated flood-plain and ephemeral-lake deposits that constitute the upper part of the TST and the lower part of the highstand systems tract (HST). These mudstone deposits eventually reduced the topographic irregularities typical of the early stage of synrift basin development, with an associated decrease in topographic-slope gradients. Finally, a high-sinuosity meandering river system drained to the south during the late highstand stage in response to the northward migration of the depocenter. The upper HST deposits are also fossiliferous and are interpreted to have been influenced by a perennial fluvial system, although the average annual discharge of this system was probably less than 5 percent of that involved in the formation of the lower TST deposits along the western basin margin. ?? 2006 Elsevier Ltd. All rights reserved.

Microbial Populations in Two Swamp Soils of South Carolina

Treesearch

David S. Priester; William R. Harms

1971-01-01

Microbial populations were counted in agar-plated samples of two swamp soils collected in summer and winter. Number of aerobic and anaerobic microorganisms differed significantly among the soils and between seasons. Alluvial soil from the river swamp was high in organic matter, N, K, Ca, and pH and averaged 88 million microorganisms per gram over the growing season....

Simultaneous determination of mercury and organic carbon using a direct mercury analyzer: Mercury profiles in sediment cores from oxbow lakes in the Mississippi Delta

USDA-ARS?s Scientific Manuscript database

Sediment cores from seasonal wetland and open water areas from six oxbow lakes in the Mississippi River alluvial flood plain were analyzed for total-mercury (Hg) using a direct mercury analyzer (DMA). In the process we evaluated the feasibility of simultaneously determining organic matter content by...

Case study: Equivalent widths of the Middle Rio Grande, New Mexico

Treesearch

Claudia Leon; Pierre Y. Julien; Drew C. Baird

2009-01-01

Successive reaches of the Rio Grande have maintained equivalent channel widths of 50 and 250 m, respectively, over long periods of time. It is hypothesized that alluvial channels adjust bed slope to match the long-term changes in channel width. Analytical relationships show that wider river reaches develop steeper slopes. A modeling approach using daily water and...

Soil physical and chemical properties associated with flat rock and riparian forest communities

Treesearch

David O. Mitchem; James E. Johnson; Laura S. Gellerstedt

2006-01-01

Flat Rock forest communities are unique ecosystems found adjacent to some large rivers in the Central and Southern Appalachian Mountains. Characterized by thin, alluvial soils overlying flat, resistant sandstone, these areas are maintained by severe flooding and have unique associated plant systems. With the advent of dams to control flooding in the 20th century, many...

Forest resources of southwest Arkansas

Treesearch

I.F. Eldredge

1937-01-01

this report deals with the forest resources in that portion of Arkansas lying west of the alluvial delta of the Mississippi River and south of the Ouachita Mountains. This area if 8,931,900 acres comprises 18 counties and parts of 4 others. Texarkana and Pine Bluff are the two largest cities in the Unit, but much of the business activity affecting the Unit centers in...

Susceptibility of major aquifers to surface contamination - Holmes, Humphreys, Issaquena, Sharkey, Washington, and Yazoo Counties, Mississippi

USGS Publications Warehouse

Moreland, Richard S.; O'Hara, Charles G.

1994-01-01

A geographic information system was used to integrate digital spatial data sets describing geology, slope of the land surface, depth to water table, soil permeability, and land use/land cover to rate the relative susceptibility of unconfined parts of the Mississippi River alluvial, Cockfield, and Sparta aquifers in west-central Mississippi to contamination from surface sources. Areas were rated as having a very low, low, moderate, high, or very high susceptibility to contamination from surface sources. Less than 1 percent of the Mississippi River alluvial aquifer has a very high susceptibility to surface contamination, 35 percent has a high susceptibility, 62 percent has a moderate susceptibility, and 2 percent has a low suscepti- bility. About 43 percent of the Cockfield aquifer has a high susceptibility to surface contamination, 57 percent has a moderate susceptibility, and less than 1 percent has a low susceptibility. About 41 percent of the Sparta aquifer has a high suscepti- bility, and less than 1 percent has a low suscepti- bility, and 1 percent has a low susceptibility. For all three aquifers, less than 1 percent has a very low susceptibility to surface contamination.

A combined morphometric, sedimentary, GIS and modelling analysis of flooding and debris flow hazard on a composite alluvial fan, Caveside, Tasmania

NASA Astrophysics Data System (ADS)

Kain, Claire L.; Rigby, Edward H.; Mazengarb, Colin

2018-02-01

Two episodes of intense flooding and sediment movement occurred in the Westmorland Stream alluvial system near Caveside, Australia in January 2011 and June 2016. The events were investigated in order to better understand the drivers and functioning of this composite alluvial system on a larger scale, so as to provide awareness of the potential hazard from future flood and debris flow events. A novel combination of methods was employed, including field surveys, catchment morphometry, GIS mapping from LiDAR and aerial imagery, and hydraulic modelling using RiverFlow-2D software. Both events were initiated by extreme rainfall events (< 1% Annual Exceedance Probability for durations exceeding 6 h) and resulted in flooding and sediment deposition across the alluvial fan. The impacts of the 2011 and 2016 events on the farmland appeared similar; however, there were differences in sediment source and transport processes that have implications for understanding recurrence probabilities. A debris flow was a key driver in the 2011 event, by eroding the stream channel in the forested watershed and delivering a large volume of sediment downstream to the alluvial fan. In contrast, modelled flooding velocities suggest the impacts of the 2016 event were the result of an extended period of extreme stream flooding and consequent erosion of alluvium directly above the current fan apex. The morphometry of the catchment is better aligned with values from fluvially dominated fans found elsewhere, which suggests that flooding represents a more frequent future risk than debris flows. These findings have wider implications for the estimation of debris flow and flood hazard on alluvial fans in Tasmania and elsewhere, as well as further demonstrating the capacity of combined hydraulic modelling and geomorphologic investigation as a predictive tool to inform hazard management practices in environments affected by flooding and sediment movement.

The Contribution of the Future SWOT Mission to Improve Simulations of River Stages and Stream-Aquifer Interactions at Regional Scale

NASA Astrophysics Data System (ADS)

Saleh, Firas; Filipo, Nicolas; Biancamaria, Sylvain; Habets, Florence; Rodriguez, Enersto; Mognard, Nelly

2013-09-01

The main objective of this study is to provide a realistic simulation of river stage in regional river networks in order to improve the quantification of stream-aquifer exchanges and better assess the associated aquifer responses that are often impacted by the magnitude and the frequency of the river stage fluctuations. This study extends the earlier work to improve the modeling of the Seine basin with a focus on simulating the hydrodynamics behavior of the Bassée alluvial wetland, a 120 km reach of the Seine River valley located south- east of Paris. The Bassée is of major importance for the drinking-water supply of Paris and surroundings, in addition to its particular hydrodynamic behavior due to the presence of a number of gravels. In this context, the understanding of stream-aquifer interactions is required for water quantity and quality preservation. A regional distributed process-based hydro(geo)logical model, Eau-Dyssée, is used. It aims at the integrated modeling of the hydrosystem to manage the various elements involved in the quantitative and qualitative aspects of water resources. Eau-Dyssée simulates pseudo 3D flow in aquifer systems solving the diffusivity equation with a finite difference numerical scheme. River flow is simulated with a Muskingum model. In addition to the in-stream discharge, a river stage estimate is needed to calculate the water exchange at the stream-aquifer interface using a conductance model. In this context, the future SWOT mission and its high-spatial resolution imagery can provide surface water level measurements at the regional scale that will permit to better characterize the Bassée complex hydro(geo)logical system and better assess soil water content. Moreover, the Bassée is considered as a potential target for the framework of the AirSWOT airborne campaign in France, 2013.

From mountains to the ocean: quantifying connectivity along the river corridor

NASA Astrophysics Data System (ADS)

Gomez-Velez, J. D.; Harvey, J. W.

2015-12-01

Rivers are the landscape's arteries; they convey water, solutes, energy, and living organisms from the hillslopes, floodplains, aquifers, and atmosphere to the oceans. As water moves along this complex circulatory system, it is continuously exchanged with the surrounding alluvial aquifer, termed hyporheic exchange, which strongly conditions and constrains the biogeochemical evolution of water at the local scale with basin-scale consequences. Over the last two decades, considerable efforts have focused on the use of detailed mathematical models to explore the hydrodynamics and biogeochemical effect of hyporheic exchange at the scale of individual channel morphologies. While these efforts are essential to gain mechanistic understanding, their computational demand makes them impractical for basin applications. In this talk, a parsimonious but physically based model of hyporheic flow for application in large river basins is presented: Networks with EXchange and Subsurface Storage (NEXSS). At the core of NEXSS are the up-scaling of detailed mathematical models and a characterization of the channel geometry, geomorphic features, and related hydraulic drivers based on scaling equations from the literature and readily accessible information such as river discharge, width, grain size, sinuosity, channel slope, and regional groundwater gradients. As a proof-of-concept, we use NEXSS to characterize the spatial and temporal variability of hyporheic exchange and denitrification potential along the Mississippi River basin. This modeling approach allows us to map the location of critical hot spots for biogeochemical transformation, their geomorphic drivers, and cumulative effect. Finally, we discuss new avenues to incorporate exchange with floodplains and ponded waters, which also play a key role in water quality along the river corridor. This new modeling approach is critical to transition from purely empirical continental models of water quality to hybrid approaches that incorporate fundamental physics and take advantage of available hydrogeomorphic data. In particular, hybrid models will be instrumental for predicting outcomes of river basin management practices under present and future socio-economic and climatic conditions.

Complex response of a midcontinent north America drainage system to late Wisconsinan sedimentation

USGS Publications Warehouse

Bettis, E. Arthur; Autin, W.J.

1997-01-01

The geomorphic evolution of Mud Creek basin in eastern Iowa, U.S.A. serves to illustrate how geomorphic influences such as sediment supply, valley gradient, climate, and vegetation are recorded in the alluvial stratigraphic record. Sediment supply to the fluvial system increased significantly during the late Wisconsinan through a combination of periglacial erosion and loess accumulation. Subsequent evolution of the Holocene alluvial stratigraphic record reflects long-term routing of the late Wisconsinan sediment through the drainage basin in a series of cut-and-fill cycles whose timing was influenced by hydrologic response to change in climate and vegetation. When viewed in a regional context, the alluvial stratigraphic record appears to reflect a long-term complex response of the fluvial system to increased sediment supply during the late Wisconsinan. Hydrologic and sediment-supply changes accompanying the spread of Euroamerican agriculture to the basin in the 180Os dramatically upset trends in sedimentation and channel behavior established during the Holocene. Copyright ?? 1997, SEPM (Society for Sedimentary Geology).

Cenozoic North American Drainage Basin Evolution, Sediment Yield, and Accumulation in the Gulf of Mexico Basin

NASA Astrophysics Data System (ADS)

Galloway, W.; Ganey-Curry, P. E.

2010-12-01

The Cenozoic fill of the Gulf of Mexico basin contains a continuous record of sediment supply from the North American continental interior for the past 65 million years. Regional mapping of unit thickness and paleogeography for 18 depositional episodes defines patterns of shifting entry points of continental fluvial systems and quantifies the total volume of sediment supplied during each episode. Eight fluvio-deltaic depocenters, named for geographic similarities to entry points and drainage basins of modern rivers, are present. From southwest to northeast, they are the Rio Bravo, Rio Grande, Guadalupe, Colorado, Houston-Brazos, Red, Mississippi, and Tennessee axes. Sediment volume was calculated from hand-contoured unit thickness maps compiled from basin-wide well and seismic control. Using a GIS algorithm to sum volumes within polygons bounding interpreted North American river contribution, the total extant volume was then calculated. General compaction factors were used to convert modern volume to quantitative approximations of total grain volume. Grain volume rate of supply for each depositional episode was then calculated. Values vary by more than an order of magnitude. Supply rate has commonly varied by two-fold or more between successive depositional episodes. Sediment supply is a significant, independent variable in development of stratigraphic sequences within the Gulf basin. Paleogeographic maps of the continental interior for eleven Cenozoic time intervals display the evolving and complex interplay of intracontinental tectonism, climate change, and drainage basin evolution. Five tectono-climatic eras are differentiated: Paleocene late Laramide era; early to middle Eocene terminal Laramide era; middle Cenozoic (Late Eocene—Early Miocene) dry, volcanogenic era; middle Neogene (Middle—Late Miocene) arid, extensional era; and late Neogene (Plio—Pleistocene) monsoonal, epeirogenic uplift era. Sediment supply to the GOM reflects the interplay of (1) areal extent of river drainage basins, (2) source area relief, (3) climate of the source areas and tributary systems, (4) source lithology, and (5) sediment storage within the upper drainage basin. Climate has played an important and complex role in modulating supply. In wet tropical to temperate climate regimes, abundant runoff efficiently removed entrained sediment. Arid climate limited runoff; resultant transport-limited tributaries and trunk streams deposited aggradational alluvial aprons, storing sediment in the drainage basin even in the absence of a structural depression. Eolian deposition commonly accompanied such alluvial aggradation. In contrast, seasonality and consequent runoff variability favored erosion and efficient sediment evacuation from the upper parts of drainage basins. Tectonism has played a prominent but equally complex role. Elevation of uplands by compression, crustal heating, or extrusive volcanism created primary loci of erosion and high sediment yield. At the same time, accompanying subsidence sometimes created long-lived sediment repositories that intercepted and sequestered sediment adjacent to sources. Regional patterns of uplift and subsidence relocated drainage divides and redirected trunk stream paths to the Gulf margin.

Avulsion at a drift-dominated mesotidal estuary: The Chubut River outlet, Patagonia, Argentina

NASA Astrophysics Data System (ADS)

Isla, Federico; Espinosa, Marcela; Rubio, Belén; Escandell, Alejandra; Gerpe, Marcela; Miglioranza, Karina; Rey, Daniel; Vilas, Federico

2015-10-01

The Chubut River flows from the Andes to the Atlantic Ocean, and is interrupted by a single dam built at the middle valley. The lower valley is dominated by the aggradation of an alluvial plain induced by a complex of spits that enclosed the inlet in the last 5000 years. The river has reduced its flow because the blocking of the upper basin by terminal moraines during the Upper Pleistocene. At least the last two marine transgressions have flooded this estuary, and contributed to the aggradation during regressions. The area is of particular interest in regard to irrigation channels practiced since the XIX century. Today, the mean monthly flow is less than 10 m3/s although peaks of 95 m3/s have been recorded in Gaiman in July 2001. The dynamics of the estuary is dominated by waves (wave-dominated estuary) as tidal effects attenuate in less than 5 km. Three vibracores were collected within this floodplain: (a) at Gaiman, an area without any effect of the sea (35 km from the coast); (b) at Trelew, at the former avulsion plain of the river (18 km from the coast); and (c) at Playa Magagna, a saltmarsh located 0.4 km from the beach. At the Gaiman core (1.54 m long) fresh-water epiphytic diatoms dominate (Epithemia sorex, Cocconeis placentula, Ulnaria ulna) suggesting the aggradation of an alluvial plain. The Trelew core (2.19 m long) was collected from a deltaic plain. It was composed by fine sand with organic matter at the base that evolved into silty layers to the top. Several unconformities and laminae with heavy minerals were detected by their geochemical composition analysed by micro X-ray fluorescence (Itrax XRF core scanner). Fine-sand laminated layers were perfectly detected by their high content in S and Cl. On the other hand, mud layers presented lower content in Mg and Al with increments in Ca and V. The core from the marsh area (1.67 m long) was analysed in terms of the diatom evolution in order to detect Holocene sea-level and salinity effects. The sand flats from the bottom of the core were dominated by Nitzchia navicularis (mesohalobous and benthic taxa) and evolved into mixed flats, mudflats and marshes to the top. Sharp contacts have been detected between these facies, with wavy and lenticular bedding characterising the mixed flat deposits. The middle of the sequence is dominated by a coastal marine diatom (Paralia sulcata) while the top was dominated by Pinnularia borealis, an aerophilous and brackish/freshwater taxa.

A conceptual model for groundwater - surface water interactions in the Darling River Floodplain, N.S.W., Australia

NASA Astrophysics Data System (ADS)

Brodie, R. S.; Lawrie, K.; Somerville, P.; Hostetler, S.; Magee, J.; Tan, K. P.; Clarke, J.

2013-12-01

Multiple lines of evidence were used to develop a conceptual model for interaction between the Darling River and associated floodplain aquifers in western New South Wales, Australia. Hydrostratigraphy and groundwater salinities were mapped using airborne electromagnetics (AEM), validated by sonic-core drilling. The AEM was highly effective in mapping groundwater freshening due to river leakage in discrete zones along the river corridor. These fresh resources occurred in both the unconfined Quaternary aquifers and the underlying, largely semi-confined Pliocene aquifers. The AEM was also fundamental to mapping the Blanchetown Clay aquitard which separates these two aquifer systems. Major-ion chemistry highlighted a mixing signature between river waters and groundwaters in both the Quaternary and Pliocene aquifers. Stable isotope data indicates that recharge to the key Pliocene aquifers is episodic and linked to high-flow flood events rather than river leakage being continuous. This was also evident when groundwater chemistry was compared with river chemistry under different flow conditions. Mapping of borehole levels showed groundwater mounding near the river, emphasising the regional significance of losing river conditions for both aquifer systems. Critically, rapid and significant groundwater level responses were measured during large flood events. In the Pliocene aquifers, continuation of rising trends after the flood peak receded confirms that this is an actual recharge response rather than hydraulic loading. The flow dependency of river leakage can be explained by the presence of mud veneers and mineral precipitates along the Darling River channel bank when river flows are low. During low flow conditions these act as impediments to river leakage. During floods, high flow velocities scour these deposits, revealing lateral-accretion surfaces in the shallow scroll plain sediments. This scouring allows lateral bank recharge to the shallow aquifer. During flood recession, mud veneers are re-deposited while transient return flows from bank storage results in carbonate precipitation in river banks. Active recharge of the Pliocene aquifers requires leakage pathways through the overlying Blanchetown Clay. Neogene-to-Present tectonic modification of the alluvial sequence, including discrete fault offsets in the Blanchetown Clay, was identified in the AEM data. Mapped faults are coincident with structures mapped in LiDAR, airborne magnetics, regional gravity, and seismic data.The study highlighted the utility of AEM in mapping the critical geological controls on groundwater-surface interaction, including the previously unrecognised tectonic influences on the largely unconsolidated alluvial sequence. Flow-dependent recharge due to changing river bed conductance has implications for groundwater assessment and management. An analysis of historic river flows suggests that active recharge would only occur for about 17% of the time when flow exceeds about 9,000 ML/d. Recharge would be negligible with groundwater extraction during low-flow conditions.

Geologic structure of the Yucaipa area inferred from gravity data, San Bernardino and Riverside Counties, California

USGS Publications Warehouse

Mendez, Gregory O.; Langenheim, V.E.; Morita, Andrew; Danskin, Wesley R.

2016-09-30

In the spring of 2009, the U.S. Geological Survey, in cooperation with the San Bernardino Valley Municipal Water District, began working on a gravity survey in the Yucaipa area to explore the three-dimensional shape of the sedimentary fill (alluvial deposits) and the surface of the underlying crystalline basement rocks. As water use has increased in pace with rapid urbanization, water managers have need for better information about the subsurface geometry and the boundaries of groundwater subbasins in the Yucaipa area. The large density contrast between alluvial deposits and the crystalline basement complex permits using modeling of gravity data to estimate the thickness of alluvial deposits. The bottom of the alluvial deposits is considered to be the top of crystalline basement rocks. The gravity data, integrated with geologic information from surface outcrops and 51 subsurface borings (15 of which penetrated basement rock), indicated a complex basin configuration where steep slopes coincide with mapped faults―such as the Crafton Hills Fault and the eastern section of the Banning Fault―and concealed ridges separate hydrologically defined subbasins.Gravity measurements and well logs were the primary data sets used to define the thickness and structure of the groundwater basin. Gravity measurements were collected at 256 new locations along profiles that totaled approximately 104.6 km (65 mi) in length; these data supplemented previously collected gravity measurements. Gravity data were reduced to isostatic anomalies and separated into an anomaly field representing the valley fill. The ‘valley-fill-deposits gravity anomaly’ was converted to thickness by using an assumed, depth-varying density contrast between the alluvial deposits and the underlying bedrock.To help visualize the basin geometry, an animation of the elevation of the top of the basement-rocks was prepared. The animation “flies over” the Yucaipa groundwater basin, viewing the land surface, geology, faults, and ridges and valleys of the shaded-relief elevation of the top of the basement complex.

Source, movement and age of groundwater in the upper part of the Mojave River Basin, California, USA

USGS Publications Warehouse

Izbicki, J.A.; Martin, P.; Michel, R.L.

1995-01-01

Water samples from wells were collected and analysed for oxygen-18, deuterium, tritium, carbon-14, and carbon-13 to determine the source, movement and age of groundwater in the upper part of the Mojave River basin. Water in the alluvial aquifer has a median deuterium composition of -66??? and contains tritium, and was recently recharged by water from the Mojave River. Water in the regional aquifer near the Mojave River, near Summit Valley, and underlying several small washes has deuterium compositions heavier than -60???. Although some water in the regional aquifer near the Mojave River contains tritium, most of this water does not contain tritium. Carbon-14 data indicate that this water was recharged less than 2400 years ago. Water in the remainder of the regional aquifer has a median deuterium composition of -84???, which is as much as 20??? lighter than the volume-weighted deuterium composition of present-day precipitation. These data show that this water was recharged under climatic conditions different from average conditions today. Carbon-14 data indicate that some water in the regional aquifer was recharged more than 20 000 years ago.Water samples from wells were collected and analyzed for oxygen-18, deuterium, tritium, carbon-14, and carbon-13 to determine the source, movement and age of groundwater in the upper part of the Mojave River basin. Water in the alluvial aquifer has a median deuterium composition of -66qq and contains tritium, and was recently recharged by water from the Mojave River. Water in the regional aquifer near the Mojave River, near Summit Valley, and underlying several small washes has deuterium compositions heavier than -60qq. Although some water in the regional aquifer near the Mojave River contains tritium, most of this water does not contain tritium. Carbon-14 data indicate that this water was recharged less than 2400 years ago. Water in the remainder of the regional aquifer has a median deuterium composition of -84qq, which is as much as 20qq lighter than the volume-weighted deuterium composition of present-day precipitation. These data show that this water was recharged under climatic conditions different from average conditions today. Carbon-14 data indicate that some water in the regional aquifer was recharged more than 20 000 years ago.

The Connection Between Sediment Supply and Paired Strath Terrace Formation at Arroyo Seco, CA, USA.

NASA Astrophysics Data System (ADS)

Finnegan, N. J.

2015-12-01

Although wide, longitudinally traceable, paired strath terraces in river canyons are frequently argued to reflect periods of higher sediment supply, there is no consensus on how changes in sediment supply translate into dramatic changes in valley morphology. Here, quantitative analysis of LiDAR data is combined with field observations in Arroyo Seco, in the Santa Lucia Range of Central California, to develop a conceptual model for paired bedrock terrace formation and its connection to sediment supply. The most recently formed bedrock terrace in Arroyo Seco grades onto a prominent alluvial fan surface, suggesting that planation of straths in Arroyo Seco occurs as downstream alluvial fans aggrade. This aggradation apparently buffers Arroyo Seco's bedrock channel from base level fall on the Reliz Canyon Fault, which separates the bedrock and alluvial sections of the river. Notably, despite the fact that bedrock terraces grade smoothly onto alluvial fan surfaces, the deep aggradation of sediment downstream is not seen upstream in bedrock channel sections. Gravel on straths is typically only 0.5-1 m thick. Instead, excess gravel appears to be accommodated by the lateral planation of the wide strath itself. LiDAR evidence suggests that strath planation is associated with braiding, which is often triggered by increases in sediment supply. Given the high lateral mobility of braided streams and the extremely fractured (and hence easily detached) mudstone valley walls along Arroyo Seco, braiding provides a simple connection between sediment supply and lateral planation in Arroyo Seco. In Arroyo Seco, fan incision (under decreased sediment supply) should exhume a bedrock step whose height represents the accumulated fault slip during fan aggradation. The upstream propagation of this exhumed step as a knickpoint provides a simple mechanism to connect drops in sediment supply to rapid vertical incision, valley narrowing and strath terrace formation. Long profile data for Arroyo Seco shows clear evidence that the last two generations of strath terraces terminate upstream at knickpoints. OSL dating (Taylor and Sweetkind, 2014) constrains the formation of the two most recent strath terraces to the last ~ 35 kyr, implying at least two reductions in sediment supply relative to capacity during this interval.

Formative flow in bedrock canyons

NASA Astrophysics Data System (ADS)

Venditti, J. G.; Kwoll, E.; Rennie, C. D.; Church, M. A.

2017-12-01

In alluvial channels, it is widely accepted that river channel configuration is set by a formative flow that represents a balance between the magnitude and frequency of flood flows. The formative flow is often considered to be one that is just capable of filling a river channel to the top of its banks. Flows much above this formative flow are thought to cause substantial sediment transport and rearrange the channel morphology to accommodate the larger flow. This idea has recently been extended to semi-alluvial channels where it has been shown that even with bedrock exposed, the flows rarely exceed that required to entrain the local sediment cover. What constitutes a formative flow in a bedrock canyon is not clear. By definition, canyons have rock walls and are typically incised vertically, removing the possibility of the walls being overtopped, as can occur in an alluvial channel at high flows. Canyons are laterally constrained, have deep scour pools and often have width to maximum depth ratios approaching 1, an order of magnitude lower than alluvial channels. In many canyons, there are a sequence of irregularly spaced scour pools. The bed may have intermittent or seasonal sediment cover, but during flood flows the sediment bed is entrained leaving a bare bedrock channel. It has been suggested that canyons cut into weak, well-jointed rock may adjust their morphology to the threshold for block plucking because the rock bed is labile during exceptionally large magnitude flows. However, this hypothesis does not apply to canyons cut into massive crystalline rock where abrasion is the dominant erosion process. Here, we argue that bedrock canyon morphology is adjusted to a characteristic flow structure developed in bedrock canyons. We show that the deeply scoured canyon floor is adjusted to a velocity inversion that is present at low flows, but gets stronger at high flows. The effect is to increase boundary shear stresses along the scour pool that forms in constricted bedrock canyons, thereby increasing abrasion rates and the potential for block plucking from massive crystalline rock beds.

Landform evolution modeling of fine-grained sedimentation on alluvial fans on Mars and Earth

NASA Astrophysics Data System (ADS)

Morgan, A. M.; Howard, A. D.; Moore, J. M.; Swander, Z. J.; Fink, D.; Korup, O.; Hesse, P. P.; Singh, T.; Srivastava, P.

2017-12-01

Reconstructing how rivers respond to changes in runoff or sediment supply by incising or aggrading has been pivotal in gauging the role of the Indian Summer Monsoon (ISM) as a geomorphic driver in the Himalayas. Here we present new data on how the fluvial systems of the Lesser Himalaya of India has responded to late Quaternary climate change. Our study is based on new chronological data for fluvial aggradation and incision from the Donga alluvial fan and several reaches of the upper Alaknanda River, as well as a meta-analysis of previous work. Fluvial sediments in the Himalayas in general, and quartz from the region in particular, have been previously noted for a number of unsuitable OSL properties including large recuperation and the existence of unremovable feldspar signals, leading to controversial discussions with regard to the reliability of existing OSL chronologies in this region. In order to improve the applicability and validity of OSL in the Lesser Himalaya, we have tested and applied pulsed OSL signals (POSL) to quartz grains from alluvial terrace and fan sediments, and propose a new chronology of regional fluvial aggradation. For previously dated terraces and alluvial fan sections, our POSL ages are systematically older than previously reported OSL ages. These results suggest periods of aggradation in the Alaknanda and Dehradun Valleys mainly between 20 and 50 ka. This most likely reflects decreased stream power during periods of weakened monsoon. The concentration of in-situ cosmogenic beryllium-10 from fluvial bedrock surfaces was also used to infer bedrock surface exposure ages, which should inform about episodes of active fluvial erosion. Resulting exposure ages span between 1.3 and 9.0 ka, suggesting that strath terraces were exposed relatively recently, and incision was dominant through most of the Holocene. In combination, our results support a precipitation-driven climatic control on fluvial dynamics, which regulates the balance between stream power and sediment supply. On a larger spatial scale, however, fluvial dynamics are probably not homogeneous as aggradation was taking place in adjacent catchments while incision dominated in the study area.

GSTARS computer models and their applications, part I: theoretical development

USGS Publications Warehouse

Yang, C.T.; Simoes, F.J.M.

2008-01-01

GSTARS is a series of computer models developed by the U.S. Bureau of Reclamation for alluvial river and reservoir sedimentation studies while the authors were employed by that agency. The first version of GSTARS was released in 1986 using Fortran IV for mainframe computers. GSTARS 2.0 was released in 1998 for personal computer application with most of the code in the original GSTARS revised, improved, and expanded using Fortran IV/77. GSTARS 2.1 is an improved and revised GSTARS 2.0 with graphical user interface. The unique features of all GSTARS models are the conjunctive use of the stream tube concept and of the minimum stream power theory. The application of minimum stream power theory allows the determination of optimum channel geometry with variable channel width and cross-sectional shape. The use of the stream tube concept enables the simulation of river hydraulics using one-dimensional numerical solutions to obtain a semi-two- dimensional presentation of the hydraulic conditions along and across an alluvial channel. According to the stream tube concept, no water or sediment particles can cross the walls of stream tubes, which is valid for many natural rivers. At and near sharp bends, however, sediment particles may cross the boundaries of stream tubes. GSTARS3, based on FORTRAN 90/95, addresses this phenomenon and further expands the capabilities of GSTARS 2.1 for cohesive and non-cohesive sediment transport in rivers and reservoirs. This paper presents the concepts, methods, and techniques used to develop the GSTARS series of computer models, especially GSTARS3. ?? 2008 International Research and Training Centre on Erosion and Sedimentation and the World Association for Sedimentation and Erosion Research.

Characteristics and origin of Earth-mounds on the Eastern Snake River Plain, Idaho

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tullis, J.A.

1995-09-01

Earth-mounds are common features on the Eastern Snake River Plain, Idaho. The mounds are typically round or oval in plan view, <0.5 m in height, and from 8 to 14 m in diameter. They are found on flat and sloped surfaces, and appear less frequently in lowland areas. The mounds have formed on deposits of multiple sedimentary environments. Those studied included alluvial gravel terraces along the Big Lost River (late Pleistocene/early Holocene age), alluvial fan segments on the flanks of the Lost River Range (Bull Lake and Pinedale age equivalents), and loess/slopewash sediments overlying basalt flows. Backhoe trenches were dugmore » to allow characterization of stratigraphy and soil development. Each mound has features unique to the depositional and pedogenic history of the site; however, there are common elements to all mounds that are linked to the history of mound formation. Each mound has a {open_quotes}floor{close_quotes} of a sediment or basement rock of significantly different hydraulic conductivity than the overlying sediment. These paleosurfaces are overlain by finer-grained sediments, typically loess or flood-overbank deposits. Mounds formed in environments where a sufficient thickness of fine-grained sediment held pore water in a system open to the migration to a freezing front. Heaving of the sediment occurred by the growth of ice lenses. Mound formation occurred at the end of the Late Pleistocene or early in the Holocene, and was followed by pedogenesis. Soils in the mounds were subsequently altered by bioturbation, buried by eolian deposition, and eroded by slopewash runoff. These secondary processes played a significant role in maintaining or increasing the mound/intermound relief.« less

Rome in its setting. Post-glacial aggradation history of the Tiber River alluvial deposits and tectonic origin of the Tiber Island

PubMed Central

Motta, Laura; Brock, Andrea L.; Macrì, Patrizia; Florindo, Fabio; Sadori, Laura; Terrenato, Nicola

2018-01-01

The Tiber valley is a prominent feature in the landscape of ancient Rome and an important element for understanding its urban development. However, little is known about the city’s original setting. Our research provides new data on the Holocene sedimentary history and human-environment interactions in the Forum Boarium, the location of the earliest harbor of the city. Since the Last Glacial Maximum, when the fluvial valley was incised to a depth of tens of meters below the present sea level, 14C and ceramic ages coupled with paleomagnetic analysis show the occurrence of three distinct aggradational phases until the establishment of a relatively stable alluvial plain at 6–8 m a.s.l. during the late 3rd century BCE. Moreover, we report evidence of a sudden and anomalous increase in sedimentation rate around 2600 yr BP, leading to the deposition of a 4-6m thick package of alluvial deposits in approximately one century. We discuss this datum in the light of possible tectonic activity along a morpho-structural lineament, revealed by the digital elevation model of this area, crossing the Forum Boarium and aligned with the Tiber Island. We formulate the hypothesis that fault displacement along this structural lineament may be responsible for the sudden collapse of the investigated area, which provided new space for the observed unusually large accumulation of sediments. We also posit that, as a consequence of the diversion of the Tiber course and the loss in capacity of transport by the river, this faulting activity triggered the origin of the Tiber Island. PMID:29590208

Characterising alluvial aquifers in a remote ephemeral catchment (Flinders River, Queensland) using a direct push tracer approach

NASA Astrophysics Data System (ADS)

Taylor, Andrew R.; Smith, Stanley D.; Lamontagne, Sébastien; Suckow, Axel

2018-01-01

The availability of reliable water supplies is a key factor limiting development in northern Australia. However, characterising groundwater resources in this remote part of Australia is challenging due to a lack of existing infrastructure and data. Here, direct push technology (DPT) was used to characterise shallow alluvial aquifers at two locations in the semiarid Flinders River catchment. DPT was used to evaluate the saturated thickness of the aquifer and estimate recharge rates by sampling for environmental tracers in groundwater (major ions, 2H, 18O, 3H and 14C). The alluvium at Fifteen Mile Reserve and Glendalough Station consisted of a mixture of permeable coarse sandy and gravely sediments and less permeable clays and silts. The alluvium was relatively thin (i.e. < 20 m) and, at the time of the investigation, was only partially saturated. Tritium (3H) concentrations in groundwater was ∼1 Tritium Unit (TU), corresponding to a mean residence time for groundwater of about 12 years. The lack of an evaporation signal for the 2H and 18O of groundwater suggests rapid localised recharge from overbank flood events as the primary recharge mechanism. Using the chloride mass balance technique (CMB) and lumped parameter models to interpret patterns in 3H in the aquifer, the mean annual recharge rate varied between 21 and 240 mm/yr. Whilst this recharge rate is relatively high for a semiarid climate, the alluvium is thin and heterogeneous hosting numerous alluvial aquifers with varied connectivity and limited storage capacity. Combining DPT and environmental tracers is a cost-effective strategy to characterise shallow groundwater resources in unconsolidated sedimentary aquifers in remote data sparse areas.

Rome in its setting. Post-glacial aggradation history of the Tiber River alluvial deposits and tectonic origin of the Tiber Island.

PubMed

Marra, Fabrizio; Motta, Laura; Brock, Andrea L; Macrì, Patrizia; Florindo, Fabio; Sadori, Laura; Terrenato, Nicola

2018-01-01

The Tiber valley is a prominent feature in the landscape of ancient Rome and an important element for understanding its urban development. However, little is known about the city's original setting. Our research provides new data on the Holocene sedimentary history and human-environment interactions in the Forum Boarium, the location of the earliest harbor of the city. Since the Last Glacial Maximum, when the fluvial valley was incised to a depth of tens of meters below the present sea level, 14C and ceramic ages coupled with paleomagnetic analysis show the occurrence of three distinct aggradational phases until the establishment of a relatively stable alluvial plain at 6-8 m a.s.l. during the late 3rd century BCE. Moreover, we report evidence of a sudden and anomalous increase in sedimentation rate around 2600 yr BP, leading to the deposition of a 4-6m thick package of alluvial deposits in approximately one century. We discuss this datum in the light of possible tectonic activity along a morpho-structural lineament, revealed by the digital elevation model of this area, crossing the Forum Boarium and aligned with the Tiber Island. We formulate the hypothesis that fault displacement along this structural lineament may be responsible for the sudden collapse of the investigated area, which provided new space for the observed unusually large accumulation of sediments. We also posit that, as a consequence of the diversion of the Tiber course and the loss in capacity of transport by the river, this faulting activity triggered the origin of the Tiber Island.

Exploring heterogeneities in a stressed alluvial aquifer using 222Rn concentrations in groundwater

NASA Astrophysics Data System (ADS)

Hillman, C. A.

2016-12-01

Understanding aquifer characteristics is important for determining the nature of groundwater flow and contaminant transport in the subsurface. Even if an alluvial aquifer can be considered homogeneous on a macro scale, groundwater models often fail to account for local heterogeneities in aquifer porosity and hydraulic conductivity. This study explores the use of 222Rn concentrations in groundwater in discerning heterogeneities in alluvial aquifer textures. The utility of 222Rn for studying the subsurface is based on its ubiquity in most rock types, its short half life (3.8 days) and its non-reactive nature. 226Ra, the direct progenitor, supplies a constant source of 222Rn to pore water and the rapid decay of 222Rn results in secular equilibrium in pore water in about 20 days. Irregularities in 222Rn concentrations throughout the aquifer may indicate differences in emanation source or emanation strength of the matrix, which is inversely related to porosity (i.e., the surface area within the recoil range of 222Rn). For this study, groundwater samples were collected from the Palo Verde Valley, a floodplain aquifer along the Colorado River in Riverside County, California. Samples were collected between 2007 and 2014 and 222Rn concentrations range from 160 to 1470 pCi/L with most samples falling between 250 and 1050 pCi/L. There is a strong positive correlation between well depth and 222Rn concentration indicating an increase in fine grained units (silts and clays) with depth. Laterally, a cluster of higher values occurs in the northeast quadrant of the study area adjacent to the river. Among the cluster of high values, though, is a sample with only 160 pCi/L possibly representing the presence of coarse-grained channel deposits.

Functional relationships between vegetation, channel morphology, and flow efficiency in an alluvial (anabranching) river

NASA Astrophysics Data System (ADS)

Jansen, John D.; Nanson, Gerald C.

2010-12-01

Water and sediment flux interactions are examined in Magela Creek, an alluvial (anabranching) sand bed river in the northern Australian tropics. Dense riparian vegetation stabilizes the channels and floodplains thereby preventing erosional instability at flow depths up to 6.2 times bankfull and discharges up to 15 times bankfull. Narrow anabranching channels characterize >92% of the alluvial reach and transport bed load more efficiently than short reaches of wide single-channels, yet overall 29 ± 12% of the bed load is sequestered and the average vertical accretion rate is 0.41 ± 0.17 mm yr-1 along the 12 km study reach. The most effective discharge for transporting sediment (40-45 m3 s-1) is consistent at all 5 stations (10 channels) examined and is equivalent to the channel-forming discharge. It has an average recurrence interval of 1.01 years, occurs for an exceptionally long portion (13-15%) of the annual flow duration, and averages a remarkable 2.1 times bankfull. The high flow efficiency (i.e., bed load transport rate to stream power ratio) of the anabranches is facilitated by low width/depth channels with banks reinforced by vegetation. Colonnades of bank top trees confine high-velocity flows overbed (i.e., over the channel bed) at stages well above bankfull. At even larger overbank flows, momentum exchange between the channels and forested floodplains restrains overbed velocities, in some cases causing them to decline, thereby limiting erosion. Magela Creek exhibits a complicated set of planform, cross-sectional and vegetative adjustments that boost overbed velocities and enhance bed load yield in multiple channels while restraining velocities and erosion at the largest discharges.

Effects of potential surface coal mining on dissolved solids in Otter Creek and in the Otter Creek alluvial aquifer, southeastern Montana

USGS Publications Warehouse

Cannon, M.R.

1985-01-01

Otter Creek drains an area of 709 square miles in the coal-rich Powder River structural basin of southeastern Montana. The Knobloch coal beds in the Tongue River Member of the Paleocene Fort Union Formation is a shallow aquifer and a target for future surface mining in the downstream part of the Otter Creek basin. A mass-balance model was used to estimate the effects of potential mining on the dissolved solids concentration in Otter Creek and in the alluvial aquifer in the Otter Creek valley. With extensive mining of the Knobloch coal beds, the annual load of dissolved solids to Otter Creek at Ashland at median streamflow could increase by 2,873 tons, or a 32-percent increase compared to the annual pre-mining load. Increased monthly loads of Otter Creek, at the median streamflow, could range from 15 percent in February to 208 percent in August. The post-mining dissolved solids load to the subirrigated part of the alluvial valley could increase by 71 percent. The median dissolved solids concentration in the subirrigated part of the valley could be 4,430 milligrams per liter, compared to the pre-mining median concentration of 2,590 milligrams per liter. Post-mining loads from the potentially mined landscape were calculated using saturated-paste-extract data from 506 overburdened samples collected from 26 wells and test holes. Post-mining loads to the Otter Creek valley likely would continue at increased rates for hundreds of years after mining. If the actual area of Knobloch coal disturbed by mining were less than that used in the model, post-mining loads to the Otter Creek valley would be proportionally smaller. (USGS)

New exploration approach: Pennsylvanian Lower Tyler central Montana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shepard, W.

Modern exploration methods utilizing a plate tectonics structural model and a recent alluvial valley analog, the Brazos from the Texas Gulf Coast, have helped revive interest in Pennsylvanian Lower Tyler exploration in the central Montana petroleum province. The central Montana trough is now visualized as an aulacogen, reaching from the Rocky Mountain trench near Butte, Montana, eastward to the Williston basin. It is 60 mi wide by about 400 mi long. Pennsylvanian Lower Tyler sediments occur in this narrow east-west-trending rift system. The regional setting is an aulacogen, or intracratonic rift, that connected the Williston basin to the Cordilleran geosynclinemore » during much of geologic time, beginning in late Precambrian. The Lower Tyler is a westward-draining Pennsylvanian (Morrowan) alluvial valley-fill system consisting of a number of river valleys that funneled into the topographic low of the aulacogen. Rift-controlled, estuarine, euxinic limestones and shales above and below the Lower Tyler provide petroleum-rich source rocks. These source rocks are mature and have generated oil, probably in the Paleocene and early Eocene. The modern Brazos River Valley of southeastern Texas is a near mirror-image analog for Lower Tyler alluvial valley fill. The Brazos valleys are 6 mi wide, 150 to 300 ft thick, and contain 60 to 70% backswamp shales and silts. Point-bar sands constitute a relatively small portion of the valley fill; the sands are 60 to 70 ft thick and about 3000 ft wide. Diagenesis has decreased net porosity distribution in the Lower Tyler to less than that of the Brazos, yet porosity parameters may still be applied to exploration in the Tyler sandstones.« less

Groundwater and surface water interaction in a basin surrounded by steep mountains, central Japan

NASA Astrophysics Data System (ADS)

Ikeda, Koichi; Tsujimura, Maki; Kaeriyama, Toshiaki; Nakano, Takanori

2015-04-01

Mountainous headwaters and lower stream alluvial plains are important as water recharge and discharge areas from the view point of groundwater flow system. Especially, groundwater and surface water interaction is one of the most important processes to understand the total groundwater flow system from the mountain to the alluvial plain. We performed tracer approach and hydrometric investigations in a basin with an area 948 square km surrounded by steep mountains with an altitude from 250m to 2060m, collected 258 groundwater samples and 112 surface water samples along four streams flowing in the basin. Also, Stable isotopes ratios of oxygen-18 (18O) and deuterium (D) and strontium (Sr) were determined on all water samples. The 18O and D show distinctive values for each sub-basin affected by different average recharge altitudes among four sub-basins. Also, Sr isotope ratio shows the same trend as 18O and D affected by different geological covers in the recharge areas among four sub-basins. The 18O, D and Sr isotope values of groundwater along some rivers in the middle stream region of the basin show close values as the rivers, and suggesting that direct recharge from the river to the shallow groundwater is predominant in that region. Also, a decreasing trend of discharge rate of the stream along the flow supports this idea of the groundwater and surface water interaction in the basin.

Selected water-quality data from the Cedar River and Cedar Rapids well fields, Cedar Rapids, Iowa, 2006-10

USGS Publications Warehouse

Littin, Gregory R.

2012-01-01

The Cedar River alluvial aquifer is the primary source of municipal water in the Cedar Rapids, Iowa area. Municipal wells are completed in the alluvial aquifer approximately 40 to 80 feet below land surface. The City of Cedar Rapids and the U.S. Geological Survey have been conducting a cooperative study of the groundwater-flow system and water quality of the aquifer since 1992. Cooperative reports between the City of Cedar Rapids and the U.S. Geological Survey have documented hydrologic and water-quality data, geochemistry, and groundwater models. Water-quality samples were collected for studies involving well field monitoring, trends, source-water protection, groundwater geochemistry, surface-water-groundwater interaction, and pesticides in groundwater and surface water. Water-quality analyses were conducted for major ions (boron, bromide, calcium, chloride, fluoride, iron, magnesium, manganese, potassium, silica, sodium, and sulfate), nutrients (ammonia as nitrogen, nitrite as nitrogen, nitrite plus nitrate as nitrogen, and orthophosphate as phosphorus), dissolved organic carbon, and selected pesticides including two degradates of the herbicide atrazine. Physical characteristics (alkalinity, dissolved oxygen, pH, specific conductance and water temperature) were measured in the field and recorded for each water sample collected. This report presents the results of routine water-quality data-collection activities from January 2006 through December 2010. Methods of data collection, quality-assurance, and water-quality analyses are presented. Data include the results of water-quality analyses from quarterly sampling from monitoring wells, municipal wells, and the Cedar River.

Population genetic structure of a widespread coniferous tree, Taxodium distichum [L.] Rich. (Cupressaceae), in the Mississippi River Alluvial Valley and Florida

USGS Publications Warehouse

Tanaka, Ayako; Ohtani, Masato; Suyama, Yoshihisa; Inomata, Nobuyuki; Tsumura, Yoshihiko; Middleton, Beth A.; Tachida, Hidenori; Kusumi, Junko

2012-01-01

Studies of genetic variation can elucidate the structure of present and past populations as well as the genetic basis of the phenotypic variability of species. Taxodium distichum is a coniferous tree dominant in lowland river flood plains and swamps of the southeastern USA which exhibits morphological variability and adaption to stressful habitats. This study provides a survey of the Mississippi River Alluvial Valley (MAV) and Florida to elucidate their population structure and the extent of genetic differentiation between the two regions and sympatric varieties, including bald cypress (var. distichum) and pond cypress (var. imbricatum). We determined the genotypes of 12 simple sequence repeat loci totaling 444 adult individuals from 18 natural populations. Bayesian clustering analysis revealed high levels of differentiation between the MAV and the Florida regions. Within the MAV region, there was a significant correlation between genetic and geographical distances. In addition, we found that there was almost no genetic differentiation between the varieties. Most genetic variation was found within individuals (76.73 %), 1.67 % among individuals within population, 15.36 % among populations within the regions, and 9.23 % between regions within the variety. Our results suggest that (1) the populations of the MAV and the Florida regions are divided into two major genetic groups, which might originate from different glacial refugia, and (2) the patterns of genetic differentiation and phenotypic differentiation were not parallel in this species.

Geomorphic effectiveness of long profile shape and role of inherent geological controls, Ganga River Basin, India

NASA Astrophysics Data System (ADS)

Sonam, Sonam; Jain, Vikrant

2017-04-01

River long profile is one of the fundamental geomorphic parameters which provides a platform to study interaction of geological and geomorphic processes at different time scales. Long profile shape is governed by geological processes at 10 ^ 5 - 10 ^ 6 years' time scale and it controls the modern day (10 ^ 0 - 10 ^ 1 years' time scale) fluvial processes by controlling the spatial variability of channel slope. Identification of an appropriate model for river long profile may provide a tool to analyse the quantitative relationship between basin geology, profile shape and its geomorphic effectiveness. A systematic analysis of long profiles has been carried for the Himalayan tributaries of the Ganga River basin. Long profile shape and stream power distribution pattern is derived using SRTM DEM data (90 m spatial resolution). Peak discharge data from 34 stations is used for hydrological analysis. Lithological variability and major thrusts are marked along the river long profile. The best fit of long profile is analysed for power, logarithmic and exponential function. Second order exponential function provides the best representation of long profiles. The second order exponential equation is Z = K1*exp(-β1*L) + K2*exp(-β2*L), where Z is elevation of channel long profile, L is the length, K and β are coefficients of the exponential function. K1 and K2 are the proportion of elevation change of the long profile represented by β1 (fast) and β2 (slow) decay coefficients of the river long profile. Different values of coefficients express the variability in long profile shapes and is related with the litho-tectonic variability of the study area. Channel slope of long profile is estimated taking the derivative of exponential function. Stream power distribution pattern along long profile is estimated by superimposing the discharge and long profile slope. Sensitivity analysis of stream power distribution with decay coefficients of the second order exponential equation is evaluated for a range of coefficient values. Our analysis suggests that the amplitude of stream power peak value is dependent on K1, the proportion of elevation change coming under the fast decay exponent and the location of stream power peak is dependent of the long profile decay coefficient (β1). Different long profile shapes owing to litho-tectonic variability across the Himalayas are responsible for spatial variability of stream power distribution pattern. Most of the stream power peaks lie in the Higher Himalaya. In general, eastern rivers have higher stream power in hinterland area and low stream power in the alluvial plains. This is responsible for, 1) higher erosion rate and sediment supply in hinterland of eastern rivers, 2) the incised and stable nature of channels in the western alluvial plains and 3) aggrading channels with dynamic nature in the eastern alluvial plains. Our study shows that the spatial variability of litho-units defines the coefficients of long profile function which in turn controls the position and magnitude of stream power maxima and hence the geomorphic variability in a fluvial system.

[Mangrove dynamics in the Cispata lagoon system (Colombian Caribbean) during last 900 years].

PubMed

Castaño, Ana; Urrego, Ligia; Bernal, Gladys

2010-12-01

The lagoon complex of Cispatá (old Sinú river delta) located at the Northwestern coast of the Colombian Caribbean, encloses one of the biggest mangrove areas in this region. This area has changed during the last 330 years because of several environmental and climatic causes, mainly changes in the position of the delta (Sinú River), which is the main freshwater source in this area, and sea level rise. We hypothesized that the climatic and geomorphologic dynamics has caused changes in the extension and composition of mangrove vegetation, especially during last 150 years. The dynamics of mangroves during the last 900 years was reconstructed based on the changes in the stratigraphy, pollen record, calcite concentrations (CaCO3) and C/N ratio, along two sediment cores from La Flotante and Navio lagoons, located in Cispatá complex. The age model was built based on lineal interpolation of 210Pb ages and changes in granulometry. Establishment and expansion of mangrove forests during the last 900 years were related to fluviomarine dynamics in the area and the lagoon formation. During the period encompassed between 1064 and 1762 A.D., the Mestizos spit was formed when marine conditions predominated in the surroundings of La Flotante Lagoon. At the site of Navío, a river dominated lagoon, terrigenous conditions dominated since 1830. Although the colonization of herbaceous pioneer vegetation started between 1142 and 1331 A.D., mangrove colonization only took place since 1717 A.D. Mangrove colonization was a result of the delta progradation. In 1849 A.D. the Sinú river delta migrated to the Cispatá bay. The eustatic sea level rise, the increase in river discharges and sedimentation rates produced the establishment of mangrove forests dominated by Rhizophora since 1849. Since 1900 a marine intrusion was recorded in both lagoons. In 1938, the migration of the delta toward its actual location in Tinajones gave place to the formation of the present lagoon system and to the expansion of mangrove forests, which reflects the balance between the high alluvial sediment input and the current sea level rise as has been recorded in similar ecosystems.

The demographic response of bank-dwelling beavers to flow regulation: A comparison on the Green and Yampa rivers

USGS Publications Warehouse

Breck, S.W.; Wilson, K.R.; Andersen, D.C.

2001-01-01

We assessed the effects of flow regulation on the demography of beavers (Castor canadensis) by comparing the density, home-range size, and body size of bank-dwelling beavers on two sixth-order alluvial river systems, the flow-regulated Green River and the free-flowing Yampa River, from 1997 to 2000. Flow regulation on the Green River has altered fluvial geomorphic processes, influencing the availability of willow and cottonwood, which, in turn, has influenced the demography of beavers. Beaver density was higher on the Green River (0.5–0.6 colonies per kilometre of river) than on the Yampa River (0.35 colonies per kilometre of river). Adult and subadult beavers on the Green River were in better condition, as indicated by larger body mass and tail size. There was no detectable difference in home-range size, though there were areas on the Yampa River that no beavers used. We attribute the improved habitat quality on the Green River to a greater availability of willow. We suggest that the sandy flats and sandbars that form during base flows and the ice cover that forms over winter on the Yampa River increase the energy expended by the beavers to obtain food and increase predation risk and thus lowers the availability of woody forage.

Sediment and channel-geometry investigations for the Kansas River bank stabilization study, Kansas, Nebraska, and Colorado

USGS Publications Warehouse

Osterkamp, W.R.; Curtis, R.E.; Crowther, H.G.

1982-01-01

Analysis of hydrologic data from the Kansas River basin suggests that the channels of the lower Solomon, Saline, and Smoky Hill Rivers have narrowed and stabilized as a result of construction of upstream reservoirs. The Kansas River channel, however, remains relatively unstable and locally active. Streamflow regulation and sediment trapping by reservoirs are possible causes of changes occurring at various Kansas River sites. An inferred deficiency of the suspended-sediment load, however, is likely to cause continuing instability. Suspended sediment in the Kansas River apparently is too sparse to form and maintain stable alluvial banks. The deficiency probably results in an increase of bed material movement, general channel widening, and local braiding. Significant channel degradation is lacking at most sites, but may occur in response to long-term (decades-to-centuries) regulation. Recent degradation near Bonner Springs, Kans., may be the result of sand and gravel removal. Any imposed changes that shorten the channel or reduce the suspended-sediment discharge of the Kansas River are expected to cause additional channel instability. (USGS)

Hydrophobic organochlorine compounds sequestered in submersed aquatic macrophytes (Hydrilla verticillata (L.F.) Royle) from the tidal Potomac River (USA).

PubMed

Hopple, J A; Foster, G D

1996-01-01

The potential for hydrophobic organochlorine contaminants to be sequestered in submersed aquatic vegetation was evaluated by determining the concentrations of cis- and trans-chlordane, dieldrin, and polychlorinated biphenyls (PCBs) in feral aquatic macrophytes (Hydrilla verticillata (L.f.) Royle) collected from the tidal Potomac River. Similarities in mean dry-weight concentrations of the identified organochlorine compounds in H. verticillata and surrounding alluvial sediments indicated that the extent of sequestration in H. verticillata was of the same magnitude as sorption of these compounds to river sediments, but some qualitative differences in PCB congener profiles existed. The results imply that to some degree H. verticillata can influence downstream fluxes of organic contaminants in fluvial transport in the Potomac River, and, furthermore, identify this species as a viable candidate organism for hydrophobic organochlorine contaminant biomonitoring in the Chesapeake Bay estuary.

Characteristics of a Recent and Prehistoric Landslides in the Pine River Valley, BC: a Mapping Effort

NASA Astrophysics Data System (ADS)

Heijenk, R.; Geertsema, M.; Miller, B.; de Jong, S. M.

2015-12-01

Spreads and other low gradient landslides are common in glacial lake sediments in north eastern British Columbia. Both pre and post glacial lake sediments, largely derived from shale bedrock are susceptible to low-gradient landslides. Bank erosion by rivers and streams and high pore pressures, have contributed to the landslides. We used LiDAR for mapping the extent of the glaciolacustrine sediments and map and characterise landslides in the Pine River valley, near Chetwynd, British Columbia. We included metrics such as travel angle, length, area, and elevation to distinguish rotational and translational landslides. We mapped 45 landslides in the Pine River valley distinguishing between rotational and translational landslides. The rotational landslides commonly have a smaller area and smaller travel length than translational landslides. Most rotational slides involved overlying alluvial fans, while most translational slides involved terraces.

Hydrophobic organochlorine compounds sequestered in submersed aquatic macrophytes (Hydrilla yerticillata (L.f.) Royle) from the tidal Potomac River (USA)

USGS Publications Warehouse

Hopple, J.A.; Foster, G.D.

1996-01-01

The potential for hydrophobic organochlorine contaminants to be sequestered in submersed aquatic vegetation was evaluated by determining the concentrations of cis- and trans-chlordane, dieldrin, and polychlorinated biphenyls (PCBs) in feral aquatic macrophytes (Hydrilla verticillata (L.f.) Royle) collected from the tidal Potomac River. Similarities in mean dry-weight concentrations of the identified organochlorine compounds in H. verticillata and surrounding alluvial sediments indicated that the extent of sequestration in H. verticillata was of the same magnitude as sorption of these compounds to river sediments, but some qualitative differences in PCB congener profiles existed. The results imply that to some degree H. verticillata can influence downstream fluxes of organic contaminants in fluvial transport in the Potomac River, and, furthermore, identify this species as a viable candidate organism for hydrophobic organochlorine contaminant biomonitoring in the Chesapeake Bay estuary.

Identify temporal trend of air temperature and its impact on forest stream flow in Lower Mississippi River Alluvial Valley using wavelet analysis

Treesearch

Ying Ouyang; Prem B. Parajuli; Yide Li; Theodor D. Leininger; Gary Feng

2017-01-01

Characterization of stream flow is essential to water resource management, water supply planning, environmental protection, and ecological restoration; while air temperature variation due to climate change can exacerbate stream flow and add instability to the flow. In this study, the wavelet analysis technique was employed to identify temporal trend of air temperature...

Hydrologic effects on diameter growth phenology for Celtis laevigata and Quercus lyrata in the floodplain of the lower White River, Arkansas

Treesearch

Scott T. Allen; Ken W. Krauss; Richard F. Keim

2016-01-01

Bottomland hardwood (BLH) forests represent an extensive wetland system in the Mississippi Alluvial Valley and southeastern USA, and it is currently undergoing widespread transition in species composition. One such transition involves increased establishment of sugarberry (Celtis laevigata), and decreased establishment of overcup oak (Quercus lyrata). The ecological...

Environmental Impact Statement for Proposed Closure of Eaker Air Force Base, Arkansas

DTIC Science & Technology

1990-05-01

alluvial floodplain of the Mississippi River . Quaternary deposits composed of clay, sandy clay, sand , and gravel occur to a depth of approximately 125...Protection Agency 1988 Bossier Parish , Louisiana : Mississippi County, Arkansas: Pulaski County, Arkansas: and Taylor County. Texas Air Quality Inventory...receiving bases: Malmstrom AFB, Montana; Barksdale AFB, Louisiana ; and Plattsburgh AFB, New York. Additional documents may be prepared 3 when the

Lateral Erosion Encourages Vertical Incision in a Bimodal Alluvial River

NASA Astrophysics Data System (ADS)

Gran, K. B.

2015-12-01

Sand can have a strong impact on gravel transport, increasing gravel transport rates by orders of magnitude as sand content increases. Recent experimental work by others indicates that adding sand to an armored bed can even cause armor to break-up and mobilize. These two elements together help explain observations from a bimodal sand and gravel-bedded river, where lateral migration into sand-rich alluvium breaks up the armor layer, encouraging further incision into the bed. Detailed bedload measurements were coupled with surface and subsurface grain size analyses and cross-sectional surveys in a seasonally-incised channel carved into the upper alluvial fan of the Pasig-Potrero River at Mount Pinatubo, Philippines. Pinatubo erupted in 1991, filling valleys draining the flanks of the volcano with primarily sand-sized pyroclastic flow debris. Twenty years after the eruption, sand-rich sediment inputs are strongly seasonal, with most sediment input to the channel during the rainy season. During the dry season, flow condenses from a wide braided planform to a single-thread channel in most of the upper basin, extending several km onto the alluvial fan. This change in planform creates similar unit discharge ranges in summer and winter. Lower sediment loads in the dry season drive vertical incision until the bed is sufficiently armored. Incision proceeds downstream in a wave, with increasing sediment transport rates and decreasing grain size with distance downstream, eventually reaching a gravel-sand transition and return to a braided planform. Incision depths in the gravel-bedded section exceeded 3 meters in parts of a 4 km-long study reach, a depth too great to be explained by predictions from simple winnowing during incision. Instead, lateral migration into sand-rich alluvium provides sufficient fine sediment to break up the armor surface, allowing incision to start anew and increasing the total depth of the seasonally-incised valley. Lateral migration is recorded in a series of inset terraces within the valley. The importance of sand on channel behavior thus extends beyond transport rates, affecting the depth of incision and volume of material excavated during a rainy to dry season transition.

Do river channels decrease in width downstream on Distributive Fluvial Systems? An evaluation of modern mega-fans

NASA Astrophysics Data System (ADS)

Espinoza, T. N.; Scuderi, L. A.; Weissmann, G. S.; Hartley, A. J.

2014-12-01

Recent studies on aggradational continental sedimentary basins globally show that fluvial deposits in most modern sedimentary basins are dominated Distributive Fluvial Systems (DFS). DFS's are identified by: (1) pattern of channels and floodplain deposits that radiate outward from an apex located where the river enters the sedimentary basin, (2) deposition where an alluvial system becomes unconfined upon entering the sedimentary basin, (3) broadly fan shaped deposit that is convex upward across the DFS and concave upward down-fan, and (4) if the DFS is incised, an intersection point above which the alluvial system is held in an incised valley and below which it distributes sediment across an active depositional lobe. Several papers about DFS hypothesized that rivers on DFS decrease in size down-fan. We are testing this hypothesis through evaluation of LANDSAT and STRM data from large DFS described by Hartley et al (2010). We use ArcGIS to: (1) open the images and merge them together if there are more than one image corresponding to the DFS being studied, (2) use a Maximum Likelihood Analysis in six classes to segment different features on the DFS (e.g. exposed sands, water, vegetation, and other fan environments), (3) isolate the classes that correspond to the active channel belt (e.g., exposed sand bars and water), (4) divide the active channel belt into 1000 m long sections, (5) determine the area of active channel belt in each section, and (6) calculate the average width of the river in each section (e.g., W = area/1000m). We present our result for each DFS river on a graph that shows the change in width downstream. Our final product will be a dataset that contains width versus distance down-fan from the apex for as many of the large DFS from Hartley et al (2010) as possible. If the hypothesis is supported, the decrease in width could have a substantial predictive significance on sandstone geometry in fluvial successions.

Regional deformation of late Quaternary fluvial sediments in the Apennines foreland basin (Emilia, Italy)

NASA Astrophysics Data System (ADS)

Stefani, Marco; Minarelli, Luca; Fontana, Alessandro; Hajdas, Irka

2018-04-01

Our research is aimed at estimating the vertical deformation affecting late Quaternary units accumulated into the foreland basin of the Northern Apennines chain. Beneath the study alluvial plain, compressive fault-fold structures are seismically active. We reconstructed the stratigraphic architecture and the depositional evolution of the alluvial deposits, which accumulated in the first 40 m of subsurface, through the last 45,000 years, from before the Last Glacial Maximum to the present. A 58 km-long stratigraphic profile was correlated from the foothill belt near Bologna to the vicinity of the Po River. The analysis of the profile documents subsidence movements through the last 12,000 years, exceeding - 18 m in syncline areas, with subsidence rates of at least 1.5 m/ka. Anticlines areas experienced a much lower subsidence than the syncline ones.

Relationship between industrial discharges and contamination of raw water resources by perfluorinated compounds: part II: Case study of a fluorotelomer polymer manufacturing plant.

PubMed

Dauchy, Xavier; Boiteux, Virginie; Rosin, Christophe; Munoz, Jean-François

2012-09-01

In this study, the concentrations of 10 perfluorinated compounds (PFCs) were measured in effluents of a fluorotelomer polymer manufacturing plant and its wastewater treatment plant. A 50-fold increase between the two effluents mass flows was observed. The water quality of two drinking water treatment plants located downstream at 15 and 25 km from the manufacturing plant was examined. An increase of the sum of PFCs was observed between the river (30 ng/L) and an alluvial well (70 ng/L), and between the raw water (9 ng/L) and the outlet of a biological treatment (97 ng/L). These results indicate a possible degradation of fluorotelomers, occurring during wastewater treatment, sediment infiltration in the alluvial aquifer, and drinking water treatment.

Paleogene Vertebrate Paleontology, Geology and Remote Sensing in the Wind River Basin

NASA Technical Reports Server (NTRS)

Stucky, R. K.; Krishtalka, L.

1985-01-01

Biostratigraphic and lithostratigraphic studies were used to correlate different events in the geologic evolution of the northeastern part of the Wind River Basin and have suggested several conclusions. Laterally equivalent exposures of the Lysite member from Cedar Ridge to Bridger Creek show a gradation in lithology from interbedded boulder conglomerates and sandstones to interbedded lenticular sandstones and mudstones to interbedded carbonaceous shales, coals and tabular sandstones. This gradation suggests a shift from alluvial fan to braided stream to paludal or lacustrine sedimentary environments during the late early Eocene. The Lysite and Lost Cabin members of the Wind River Formation are in fault contact in the Bridger Creek area and may intertongue to the east along Cedar Ridge. Ways in which remote sensing could be used in these studies are discussed.

Fertilizers mobilization in alluvial aquifer: laboratory experiments

NASA Astrophysics Data System (ADS)

Mastrocicco, M.; Colombani, N.; Palpacelli, S.

2009-02-01

In alluvial plains, intensive farming with conspicuous use of agrochemicals, can cause land pollution and groundwater contamination. In central Po River plain, paleo-channels are important links between arable lands and the underlaying aquifer, since the latter is often confined by clay sediments that act as a barrier against contaminants migration. Therefore, paleo-channels are recharge zones of particular interest that have to be protected from pollution as they are commonly used for water supply. This paper focuses on fertilizer mobilization next to a sand pit excavated in a paleo-channel near Ferrara (Italy). The problem is approached via batch test leaking and columns elution of alluvial sediments. Results from batch experiments showed fast increase in all major cations and anions, suggesting equilibrium control of dissolution reactions, limited availability of solid phases and geochemical homogeneity of samples. In column experiments, early elution and tailing of all ions breakthrough was recorded due to preferential flow paths. For sediments investigated in this study, dispersion, dilution and chemical reactions can reduce fertilizers at concentration below drinking standards in a reasonable time frame, provided fertilizer loading is halted or, at least, reduced. Thus, the definition of a corridor along paleo-channels is recommended to preserve groundwater quality.

Probable flood predictions in ungauged coastal basins of El Salvador

USGS Publications Warehouse

Friedel, M.J.; Smith, M.E.; Chica, A.M.E.; Litke, D.

2008-01-01

A regionalization procedure is presented and used to predict probable flooding in four ungauged coastal river basins of El Salvador: Paz, Jiboa, Grande de San Miguel, and Goascoran. The flood-prediction problem is sequentially solved for two regions: upstream mountains and downstream alluvial plains. In the upstream mountains, a set of rainfall-runoff parameter values and recurrent peak-flow discharge hydrographs are simultaneously estimated for 20 tributary-basin models. Application of dissimilarity equations among tributary basins (soft prior information) permitted development of a parsimonious parameter structure subject to information content in the recurrent peak-flow discharge values derived using regression equations based on measurements recorded outside the ungauged study basins. The estimated joint set of parameter values formed the basis from which probable minimum and maximum peak-flow discharge limits were then estimated revealing that prediction uncertainty increases with basin size. In the downstream alluvial plain, model application of the estimated minimum and maximum peak-flow hydrographs facilitated simulation of probable 100-year flood-flow depths in confined canyons and across unconfined coastal alluvial plains. The regionalization procedure provides a tool for hydrologic risk assessment and flood protection planning that is not restricted to the case presented herein. ?? 2008 ASCE.

Avulsion vs Continuous Shifting: the Dynamics of Delta Distributary Channels Controlled by Basin Water Depth

NASA Astrophysics Data System (ADS)

Muto, T.; Naruse, H.

2015-12-01

An open question in the experimental study of surface processes is how basin water depth controls the dynamics of delta distributary channels. A recently suggested idea as to the issue is that, if a set of peculiar conditions is assumed, all of delta progradation, channel migration, alluvial aggradation and attainment of, or how close to, alluvial grade can be given by an identical formula with the same numerical value that is specified with dimensionless basin water depth. As one step ahead from this notion, we here report the finding obtained from a new series of tank experiments that basin water depth can also affect the modes by which active distributary channels change their locations, i.e. which one of avulsion and continuous shifting is predominant over the other. The results of the experiments clearly indicate that continuous shifting tends to become more predominant over avulsion as basin water depth increases. This tendency is related to a progressive decrease/increase in rate of alluvial aggradation which directly controls avulsion frequency. The present experimental notion can be examined with stratigraphic records of river deltas that accumulated with increasing or decreasing basin water depth.

Impact of Sand and Gravel Mining on Groundwater Resources in La Bassée Alluvial Plain, France.

NASA Astrophysics Data System (ADS)

Jost, A.; Wang, S.; Labarthe, B.; Flipo, N.

2016-12-01

The alluvial plain of La Bassée, in the middle reach of the Seine River (France), is both of environmental importance as a major wetland and at the centre of strategic issues regarding inland waterways transport, flood prevention, water and granular resources. The sand and gravel mining industry has been productive for more than five decades over the area and contributes to 40% of the regional production of natural aggregates. Former and active gravel pits cover about 10% of the areal extent of the plain. Gravel pit lakes interact with groundwater from the surrounding alluvial aquifer and the underlying chalk aquifer. By exposing groundwater to the atmosphere, they can act as a sink/source for the groundwater system through atmospheric exchange. We develop a model-based approach using the EauDyssée platform for determining the impact of such lakes on groundwater resources in terms of quantity and how they affect groundwater level and flow paths. Over the alluvial plain area of La Bassée a local model is built, which takes its hydrodynamic parameters from an inverse calibration procedure and its boundary conditions from a coarser regional model run on the whole Seine basin. To efficiently simulate lake-groundwater exchange, the modelling platform was extended by a lake module. The effet of gravel excavation is investigated by quantifying the gravel pit lakes water budget and by simulating groundwater transient response over almost two decades.

Geomorphic effects of large debris flows and flash floods, northern Venezuela, 1999

USGS Publications Warehouse

Larsen, M.C.; Wieczorek, G.F.

2006-01-01

A rare, high-magnitude storm in northern Venezuela in December 1999 triggered debris flows and flash floods, and caused one of the worst natural disasters in the recorded history of the Americas. Some 15,000 people were killed. The debris flows and floods inundated coastal communities on alluvial fans at the mouths of a coastal mountain drainage network and destroyed property estimated at more than $2 billion. Landslides were abundant and widespread on steep slopes within areas underlain by schist and gneiss from near the coast to slightly over the crest of the mountain range. Some hillsides were entirely denuded by single or coalescing failures, which formed massive debris flows in river channels flowing out onto densely populated alluvial fans at the coast. The massive amount of sediment derived from 24 watersheds along 50 km of the coast during the storm and deposited on alluvial fans and beaches has been estimated at 15 to 20 million m3. Sediment yield for the 1999 storm from the approximately 200 km2 drainage area of watersheds upstream of the alluvial fans was as much as 100,000 m3/km2. Rapid economic development in this dynamic geomorphic environment close to the capital city of Caracas, in combination with a severe rain storm, resulted in the death of approximately 5% of the population (300,000 total prior to the storm) in the northern Venezuelan state of Vargas. ?? 2006 Gebru??der Borntraeger.

The Evolution of the Lower Missouri River: National Mapping Discipline Research at Lisbon Bottom

USGS Publications Warehouse

,

2002-01-01

Before 1800, the Missouri River was one of North America's most diverse and dynamic ecosystems. During the past 200 years, civil engineering has transformed it into a navigation system regulated by reservoirs and confined by bank stabilization and flood control structures. These modifications have reduced seasonal flow variability and sediment load and have disconnected the river from backwater, off-channel, and floodplain habitats. Flooding along the Lower Missouri River in 1993 and again in 1996 created a side-channel chute across Lisbon Bottom, a well-formed loop bottom near Glasgow, Mo. The formation and subsequent development of the chute have provided USGS scientists with a glimpse of a preregulated Missouri River. Knowledge of geologic characteristics and processes in an alluvial setting like Lisbon Bottom provides a scientific basis for floodplain management. This knowledge is also vital to a complete understanding of riverine habitat disturbance, recovery, and rehabilitation. A critical component of this knowledge is an understanding of the spatial and temporal relationships between riverine habitats and geomorphic processes.

Laboratory Alluvial Rivers

NASA Astrophysics Data System (ADS)

Devauchelle, O.; Abramian, A.; Seizilles, G.; Lajeunesse, E.

2015-12-01

By which physical mechanisms does a river select its shape and size? We investigate this question using small laboratory rivers formed by laminar flows.In its simplest form, this experiment consists in a flow of glycerol over a uniform layer of plastic sediments. After a few hours, a channel forms spontaneously, and eventually reaches a stable geometry. This equilibrium state corresponds accurately to the force balance proposed by Henderson (1961).If we impose a sediment discharge at the inlet of the experiment, the river adjusts to this boundary condition by widening its channel. Observation suggests that this new equilibrium results from the balance between gravity, which pulls the entrained grains towards the center of the channel, and bedload diffusion, which returns them towards the banks. This balance explains why experimental rivers get wider and shallower as their sediment load increases.However, to test quantitatively this theory against observation, we need to evaluate independently the effect of transverse slope on bedload transport. We propose to use an instability generated by bedload diffusion to do so.

Decreasing flood risk perception in Porto Alegre - Brazil and its influence on water resource management decisions

NASA Astrophysics Data System (ADS)

Allasia, D. G.; Tassi, R.; Bemfica, D.; Goldenfum, J. A.

2015-06-01

Porto Alegre is the capital and largest city in the Brazilian state of Rio Grande do Sul in Southern Brazil with approximately 1.5 million inhabitants. The city lies on the eastern bank of the Guaiba Lake, formed by the convergence of five rivers and leading to the Lagoa dos Patos, a giant freshwater lagoon navigable by even the largest of ships. This river junction has become an important alluvial port as well as a chief industrial and commercial centre. However, this strategic location resulted in severe damage because of its exposure to flooding from the river system, affecting the city in the years 1873, 1928, 1936, 1941 and 1967. In order to reduce flood risk, a complex system of levees and pump stations was implemented during 1960s and 1970s. Since its construction, not a single large flood event occurred. However, in recent years, the levees in the downtown region of Porto Alegre were severally criticized by city planners and population. Several projects have been proposed to demolish the Mauá Wall due to the false perception of lack of flood risk. Similar opinions and reactions against flood infrastructure have been observed in other cities in Brazil, such as Itajaí and Blumenau, with disastrous consequences. This paper illustrates how the perception of flood risk in Porto Alegre has changed over recent years as a result of flood infrastructure, and how such changes in perceptions can influence water management decisions.

Partition of heavy metals in a tropical river system impacted by municipal waste.

PubMed

Duc, Trinh Anh; Loi, Vu Duc; Thao, Ta Thi

2013-02-01

A research program was established to identify the governing factors for the partition coefficient (K(D)) of heavy metals between suspended particulate and dissolved phases in the Day River system a tropical, highly alluvial aquatic system, in Vietnam. The targeted river system, draining an urbanized-industrialized catchment where discharged wastewater is mostly untreated, could be separated into the least impacted, pristine area, and the most impacted, polluted area. Organic matter degradation was shown to govern the variation of parameters like total organic carbon, biochemical oxygen demand, chemical oxygen demand, nutrients, conductivity, or redox potential. Heavy metals in both dissolved and particulate phases were enriched in severely polluted area because of wastewater inflow that contains concentrated metals and intensification of metal influx from sediment. Results show log K(D) in the order Mn < As < Zn < Hg < Ni < Cu < Cd < Co < Pb < Cr < Fe and As < Zn < Ni < Mn < Cr < Cu < Co < Fe in the polluted zone and the pristine zone, respectively. A decreasing tendency of partition coefficients of 11 heavy metals considered from the pristine to the impacted zones was observed. Three explanations for the difference are: (1) increase of solubility of most heavy metals in low redox potential, (2) competition for the binding sites with major and minor cations, and (3) complexation with dissolved organic matter concentrated in municipal waste impacted water. Apart from domestic waste impact, statistical analysis has contributed to identify the influence of climate condition and hydrological regime to the partition of heavy metals in the area.

Strong Paleoearthquakes along the Aksuu Border Fault according to the Results of Dating the Offset Terrace Complex of the Chon-Aksuu River, Northern Tien Shan

NASA Astrophysics Data System (ADS)

Korzhenkov, A. M.; Arrowsmith, J. R.; Crosby, C. J.; Guralnik, B.; Rogozhin, E. A.; Sorokin, A. A.; Abdieva, S. V.; Fortuna, A. B.; Yudakhin, A. S.; Agatova, A. R.; Deev, E. V.; Mazeika, J. V.; Rodkin, M. V.; Shen, J.

2018-03-01

The study and radiocarbon dating of the low alluvial terraces of the Chon-Aksuu River, in the Northern Issyk-Kul region, which were broken by the Kebin (Kemin) earthquake of 1911 (Ms = 8.2, Io = 10 to 11), are carried out. The obtained radiocarbon dated ages refer to the second half of the Holocene. Since that time, at least eight strong earthquakes took place along this (Chon-Aksuu) segment of the Aksuu border fault. Three seismic events, including the earthquake of 1911 occurred in the second millennium A.D. This outburst of seismic energy was preceded by two millennia of seismic quiescence, which set in after another pulse of seismic activation. The latter lasted for 1.5 millennia and included five strong earthquakes. The recurrence period of seismic events during the activations is 300-600 years. Hence, the seismic regime along the Chon-Aksuu segment of the Aksuu border fault in the second half of the Holocene was a succession of two seismic activations, each with a duration of 1.0-1.5 ka, which were separated by a 2-ka interval of seismic quiescence. Therefore, the absolute datings of the river terraces of different ages which have been broken by a seismogenic rupture can serve as a reliable source of information about the age of the strong earthquakes that occurred along the seismogenic fault.

Projected ground-water development, ground-water levels, and stream-aquifer leakage in the South Fork Solomon River Valley between Webster Reservoir and Waconda Lake, north-central Kansas, 1979-2020

USGS Publications Warehouse

Kume, Jack; Lindgren, R.J.; Stullken, L.E.

1985-01-01

A two-dimensional finite difference computer model was used to project changes in the potentiometric surface, saturated thickness, and stream aquifer leakage in an alluvial aquifer resulting from four instances of projected groundwater development. The alluvial aquifer occurs in the South Fork Solomon River valley between Webster Reservoir and Waconda Lake in north-central Kansas. In the first two projections, pumpage for irrigation was held constant at 1978 rates throughout the projection period (1979-2020). In the second two projections, the 1978 pumpage was progressively increased each yr through 2020. In the second and fourth projections, surface water diversions in the Osborne Irrigation Canal were decreased by 50 %. For the third and fourth projections, each grid-block in the modeled area was classified initially as one of six types according to whether it represented irrigable or nonirrigable land, to its saturated thickness, to its location inside or outside the canal-river area, and to its pumping rate. The projected base-flow rates (leakage from the aquifer to the river) were lower during the irrigation season (June, July, and August) than during the other months of the yr because of the decline in hydraulic head produced by groundwater pumpage. Stream depletion, calculated as a decrease below the average (1970-78) estimated winter base-flow rate of 16.5 cu ft/sec, varied inversely with base flow. For the first two projections, a constant annual cycle of well pumpage and recharge was used throughout the projection period. Aquifer leakage to the river was nearly constant by the mid-to-late 1990's, implying that flow conditions had attained a stabilized annual cycle. The third and fourth projections never attained an annual stabilized cycle because the irrigation pumpage rate was increased each year. By the early 1980's, the hydraulic head had fallen below river stage, reversing the hydraulic gradient at the stream-aquifer interface and resulting in net leakage from the river to the aquifer during the summer months. By the early 1990 's, the projected potentiometric surface of the aquifer was lower than the river stage even during the winter and spring months. (Author 's abstract)

Aggradation and degradation of alluvial sand deposits, 1965 to 1986, Colorado River, Grand Canyon National Park, Arizona

USGS Publications Warehouse

Schmidt, John C.; Graf, Julia B.

1990-01-01

Alluvial sand deposits along the Colorado River in Grand Canyon National Park are used as campsites and are substrate for vegetation. The largest and most numerous of these deposits are formed in zones of recirculating current that are created downstream from where the channel is constricted by debris fans at tributary mouths. Alluvial sand deposits are classified by location and form. Separation and reattachment deposits are downstream from constrictions within recirculation zones. Separation deposits are near the point of flow separation and typically mantle large debris fans. Reattachment deposits are near the point of flow reattachment and project upstream beneath much of the zone of recirculating current. Upper-pool deposits are upstream from a constriction and are associated with backwaters. Channel-margin deposits line the channel and have the form of terraces. Some are created in small recirculation zones. Reattachment and channel-margin deposits are largest and most numerous in wide reaches, although small channel-margin deposits are used as campsites in the narrow Muav Gorge. Separation deposits are more uniformly distributed throughout Grand Canyon National Park than are other types of deposits. In some narrow reaches where the number of alluvial sand deposits used as campsites is small, separation deposits are a high percentage of the total. During high flows, both separation and reattachment deposits are initially scoured but are subsequently redeposited during flow recession. Sand is also exchanged between the main channel and recirculation zones. The rate of recession of high flows can affect the elevation of alluvial deposits that are left exposed after a flood has passed. Fluctuating flows that follow a period of steady discharge cause initial erosion of separation and reattachment deposits. A part of this eroded sand is transported to the main channel. Therefore, sand is exchanged between the main channel and recirculation zones and redistributed within recirculation zones over a broad range of discharges. Comparison of aerial photographs and reinterpretation of published data concerning changes of alluvial sand deposits following recession of high flows in 1983 and 1984 indicate that sand was eroded from recirculation zones in narrow reaches. In wide reaches, however, aggradation in recirculation zones may have occurred. In narrow reaches, the decrease of reattachment deposits was greater than that of separation deposits. In all reaches, the percentage of separation deposits that maintained a constant area was greater than for other deposits. Separation deposits, therefore, appear to be the most stable of the deposit types. Fluctuating flows between October 1985 and January 1986, which followed the higher and steadier flows of 1983 to 1985, caused erosion throughout the park. For separation deposits, erosion was greatest at those sites where deposition from the 1983 high flows had been greatest. The existing pattern of low campsite availability in narrow reaches and high campsite availability in wide reaches was thus accentuated by the sequence of flows between 1983 and 1985.

Floodplain Connectivity and implications for flooding and floodplain function

NASA Astrophysics Data System (ADS)

Barrow, E.

2017-12-01

Regime theory suggests that floodplains should be inundated on average once every two years to maintain form and function of both the river and the floodplain. Natural disconnection along non-alluvial reaches and where the river has moved to flow against terrace edges is to be expected, however, disconnectivity caused by river management is now affecting increasing lengths of watercourses. This study utilises aerial Lidar data to determine the relative height difference between the watercourse and adjacent valley bottoms to assess the degree of disconnectivity along main river systems across Cumbria in the UK. The results reveal that many rivers are now poorly connected to their floodplains which are now largely non-functional. Floodplain geomorphic units, although often present, are currently inactive and water table levels are reduced resulting in a loss of wetland in favour of ruderal species tolerant of drier conditions. The causes of such widespread disconnectivity may be attributed to historic dredging and straightening of these rivers and revetment and riparian tree planting has further exacerbated the problem restricting lateral activity and the subsequent development of new areas of connected floodplain. The high degree of disconnection has implications for future river management and river restoration and these are discussed.

Development of an Environmental Flow Framework for the McKenzie River Basin, Oregon

USGS Publications Warehouse

Risley, John; Wallick, J. Rose; Waite, Ian; Stonewall, Adam J.

2010-01-01

The McKenzie River is a tributary to the Willamette River in northwestern Oregon. The McKenzie River is approximately 90 miles in length and has a drainage area of approximately 1,300 square miles. Two major flood control dams, a hydropower dam complex, and two hydropower canals significantly alter streamflows in the river. The structures reduce the magnitude and frequency of large and small floods while increasing the annual 7-day minimum streamflows. Stream temperatures also have been altered by the dams and other anthropogenic factors, such as the removal of riparian vegetation and channel simplification. Flow releases from one of the flood control dams are cooler in the summer and warmer in the fall in comparison to unregulated flow conditions before the dam was constructed. In 2006, the Oregon Department of Environmental Quality listed a total of 112.4, 6.3, and 55.7 miles of the McKenzie River basin mainstem and tributary stream reaches as thermally impaired for salmonid rearing, salmonid spawning, and bull trout, respectively. The analyses in this report, along with previous studies, indicate that dams have altered downstream channel morphology and ecologic communities. In addition to reducing the magnitude and frequency of floods, dams have diminished sediment transport by trapping bed material. Other anthropogenic factors, such as bank stabilization, highway construction, and reductions of in-channel wood, also have contributed to the loss of riparian habitat. A comparison of aerial photography taken in 1939 and 2005 showed substantial decreases in secondary channels, gravel bars, and channel sinuosity, particularly along the lower alluvial reaches of the McKenzie River. In addition, bed armoring and incision may contribute to habitat degradation, although further study is needed to determine the extent of these processes. Peak streamflow reduction has led to vegetation colonization and stabilization of formerly active bar surfaces. The large flood control dams on Blue River and South Fork McKenzie River likely have had the greatest effect on downstream habitats because these sediment and flood-rich tributaries historically contributed a disproportionate volume of bed material, wood, and peak flows in comparison with the spring-fed tributaries of the upper McKenzie River basin. The ecological effects of the dams were examined by focusing on nine exemplar aquatic and terrestrial species, including spring Chinook salmon, bull trout, Oregon chub, Pacific and western brook lamprey, red-legged frog, western pond turtle, alder, and cottonwood. The changes caused by the dams to streamflow hydrograph affect all these and other species in complex ways, although a few commonalities are apparent. A loss of channel complexity in the McKenzie River basin, which is associated with the reduction in flood events and widespread channel stabilization, is the primary factor related to the observed population declines for all nine exemplar species. The dams also have caused direct ecological effects by blocking access to habitat, changing the amount and timing of available critical habitat, and changing water temperature during important seasons for different life stages.

Geology and hydrology of the Fort Belknap Indian Reservation, Montana

USGS Publications Warehouse

Alverson, Douglas C.

1965-01-01

The Fort Belknap Indian Reservation includes an area of 970 square miles in north-central Montana. At its north edge is the Milk River valley, which is underlain by Recent alluvium of the Milk River, glacial deposits, and alluvial deposits of the preglacial Missouri River, which carved and occupied this valley before the Pleistocene Epoch. Rising gently to the south is an undulating glaciated plain broken only by three small syenite porphyry intrusions. Underlying the glacial till of the plain are Upper Cretaceous shale and sandstone of the Bearpaw and Judith River Formations. At the south end of the reservation, 40 miles from the Milk River, an intrusion of syenite porphyry in Tertiary time uplifted, tilted, and exposed the succession of sedimentary rocks overlying the Precambrian metamorphic basement. The sedimentary rocks include 1,000 feet of sandstone and shale of Cambrian age; 2,000 feet of limestone and dolomite of Ordovician, Devonian, and Mississippian age; 400 feet of shale and limestone of Jurassic age; and 3,500 feet of sandstone, siltstone, and shale of Cretaceous age. Extensive gravel terraces of Tertiary and Quaternary age bevel the upturned bedrock formations exposed around the Little Rocky Mountains. Ground water under water-table conditions is obtained at present from alluvium, glaciofluvial deposits, and the Judith River Formation. The water table ranges in depth from a few feet beneath the surface in the Milk River valley alluvium to more than 100 feet deep in the Judith River Formation. Yields to wells are generally low but adequate for domestic and stock-watering use. Quality of the water ranges from highly mineralized and unusable to excellent; many wells in the Milk River valley have been abandoned because of the alkalinity of their water. Potential sources of additional ground-water supplies are the alluvial gravel of creeks issuing from the Little Rocky Mountains and some extensive areas of terrace gravel. The uplift and tilting of the sedimentary sequence around the Little Rocky Mountains and the minor intrusions in the central plain have created artesian conditions within aquifers. Wells obtain artesian water from sandstone aquifers in the Judith River, Eagle, and Kootenai Formations. Other potential aquifers, near their outcrop areas, are the Ellis Group and the Mission Canyon Limestone. Most wells that flow at the surface have small yields, but discharges of as much as 150 gallons per minute have been noted. Quality of artesian water ranges from poor to good. Well depths range from less than 50 to more than 300 feet.

Reconstructing the Geomorphological Evolution of the Plain of Xanthos (SW Turkey) during the Holocene : a Geoarchaeological Approach

NASA Astrophysics Data System (ADS)

Ecochard, E.; Fouache, E.; Kuzucuoǧlu, C.; Carcaud, N.; Ekmekçi, M.; Ulusoy, I.; Robert, V.; Çiner, A.; Des Courtils, J.

2009-04-01

In the Hellenistic period, according to Strabo, Xanthos and Letoon were very important cities and major holy places in Lycia, a peninsula in southwestern contemporary Turkey. An archaeological study of the sites of Xanthos and Letoon cannot assume that the environment in which they are located did not change since the arrival of the first settlers in the seventh century BC. The rise of the sea level in the last 15,000 years and the subsequent Holocene alluviation has a strong impact on the landscape. The river Esen Çayı meandered in the valley leaving alluvial deposits, and the slopes were eroded. The geography of the valley of the river Esen Çayı during the Lycian and Hellenistic periods, i.e. during the 1st millennium BC, yet remains significantly unknown. What was the landscape around the Letoon shrine like? Where were the river channels? What was the progradation stage of the deltaic plain? To what extent did the slope mobility determine the location of settlements and ancient roads? To answer these questions, geomorphological dynamics at work throughout the Holocene must be reconstructed. In this communication, preliminary results from the analysis of cores and geophysical profiles, both performed during and after four field work seasons in the plain, are compared with the historical, archaeological and literary data, and a first reconstruction of the changing landscape is proposed. The sedimentary records indicate that a marine bay was gradually closed by the development of coastal sand deposits, prompting the development of a lagoonal system. As lagoons and wetlands have long been dominant in the plain, both sites probably developed in this type of landscape. In front of the Letoon site, a channel of the river Esen Çayı has been identified. It probably allowed for a direct connection by boat between the holy place and the sea downstream, and with the city of Xanthos upstream. This channel was probably responsible of the gradual sinking of the sanctuary below the alluvial deposits. The study of the morphology of the valley reveals the high mobility of landscapes in time and space. The mobility of slopes and rivers forced men to carefully choose the location of their settlements, which they often settled on rocky promontories isolated from slopes. The roads were probably established on the right bank of the river, where the slopes are less steep. The mobility of the landscape was also exploited with a symbolic aim: the Letoon shrine was installed in a hostile environment of wetlands in the middle of the floodplain, as a challenge to the laws of nature. Not only did the ancient societies adapt themselves to environmental constraints, but they also participated in the production of landscapes, with pragmatic and symbolic aims.

Alluvial and riparian soils as major sources of lead exposure in young children in the Philippines: the role of floods.

PubMed

Ostrea, Enrique M; Ostrea, Angelo M; Villanueva-Uy, Ma Esterlita; Chiodo, Lisa; Janisse, James

2015-04-01

The objective of this paper was to determine the prevalence and sources of high lead (Pb) exposure among children in Bulacan, Philippines. A total of 150 children (6-7 years old) and their caregivers were studied. Lead was analyzed in children hair and deciduous teeth. Sources of lead exposure were determined by caregiver interview and Pb analysis of house soil, drinking faucet water, air, and water from seven Bulacan rivers. Lead was positive in 91.3% of children's hair (MC or median concentration = 8.9 μg/g; range = 0-38.29), in 46.2% of the teeth (MC = 0.000 μg/mg in positive samples; range = 0.00-0.020), in 100% of soil (MC = 27.06 mg/kg; range = 3.05-1155.80), in 21.1% of air (MC = 0 μg/Ncm; range = 0-0.10), in 4% of house, faucet water (MC = 0.0 ppm; range = 0-40). There was a significant correlation (Spearman's rho) between Pb in children's hair and soil (r = 0.195; p = 0.017) and between Pb in house water and outdoor air (r = 0.616; p = 0.005). There is no significant correlation between Pb in children's hair and teeth. None of the potential sources of Pb from interview were related to lead exposure in the children. Water from seven Bulacan rivers was 100% positive for lead (MC = 70.00 ppb; range = 30-90). Widespread flooding with river overflow occurred in Bulacan in 2009 which likely caused lead contamination of the soil. There was no significant difference in the lead concentration of the soil whether near or far from the river (p = 0.205, Mann-Whitney U test). High lead exposure in children in Bulacan is likely from soil contaminated by lead-polluted rivers during flooding. In areas where flooding is common, alluvial and riparian soils from polluted rivers are important sources of lead exposure in children.

Assessment of uncertainties in soil erosion and sediment yield estimates at ungauged basins: an application to the Garra River basin, India

NASA Astrophysics Data System (ADS)

Swarnkar, Somil; Malini, Anshu; Tripathi, Shivam; Sinha, Rajiv

2018-04-01

High soil erosion and excessive sediment load are serious problems in several Himalayan river basins. To apply mitigation procedures, precise estimation of soil erosion and sediment yield with associated uncertainties are needed. Here, the revised universal soil loss equation (RUSLE) and the sediment delivery ratio (SDR) equations are used to estimate the spatial pattern of soil erosion (SE) and sediment yield (SY) in the Garra River basin, a small Himalayan tributary of the River Ganga. A methodology is proposed for quantifying and propagating uncertainties in SE, SDR and SY estimates. Expressions for uncertainty propagation are derived by first-order uncertainty analysis, making the method viable even for large river basins. The methodology is applied to investigate the relative importance of different RUSLE factors in estimating the magnitude and uncertainties in SE over two distinct morphoclimatic regimes of the Garra River basin, namely the upper mountainous region and the lower alluvial plains. Our results suggest that average SE in the basin is very high (23 ± 4.7 t ha-1 yr-1) with higher values in the upper mountainous region (92 ± 15.2 t ha-1 yr-1) compared to the lower alluvial plains (19.3 ± 4 t ha-1 yr-1). Furthermore, the topographic steepness (LS) and crop practice (CP) factors exhibit higher uncertainties than other RUSLE factors. The annual average SY is estimated at two locations in the basin - Nanak Sagar Dam (NSD) for the period 1962-2008 and Husepur gauging station (HGS) for 1987-2002. The SY at NSD and HGS are estimated to be 6.9 ± 1.2 × 105 t yr-1 and 6.7 ± 1.4 × 106 t yr-1, respectively, and the estimated 90 % interval contains the observed values of 6.4 × 105 t yr-1 and 7.2 × 106 t yr-1, respectively. The study demonstrated the usefulness of the proposed methodology for quantifying uncertainty in SE and SY estimates at ungauged basins.

Report on: Connecticut River Streambank Erosion Study, Massachusetts, New Hampshire and Vermont

DTIC Science & Technology

1979-11-01

Plastic filter cloths are used with considerable success beneath tiprap and other revetment materials such as articulated concrete blocks . The...rihutior unlimited II. SUPPLEMENTARY NOTES It. KEY WORDS (Continue on fever&e elde ifneceeeery and identify by block number). alluvial channel...erosion boat waves shear stress rock riprap lower bank erosion revetments flow control vegetation 20. ABSTRACT (Continue on reverse aide if neceesary and

Sweetgum Blight as Related to Alluvial Soils of the Mississippi River Floodplain

Treesearch

E. Richard Toole; W. M. Broadfoot

1959-01-01

A BLIGHT OF UNKNOWN origin and cause has been very common throughout much of the range of sweetgum (Liquidambar styraci flua L.) since 1950. It is characterized by a gradual dying of the tree, often from the top down. The first visible indication is a thinning of a portion of the crown, caused when some buds fail to open and others produce only dwarfed, yellowish...