Science.gov

Sample records for headwater basin subject

  1. Ecological restoration of Xingu Basin headwaters: motivations, engagement, challenges and perspectives.

    PubMed

    Durigan, Giselda; Guerin, Natalia; da Costa, José Nicola Martorano Neves

    2013-06-05

    Over the past two decades, the headwaters of the Xingu Basin in the Amazon have been subjected to one of the highest deforestation rates in Brazil, with negative effects on both terrestrial and aquatic systems. The environmental consequences of forest land conversion have concerned the indigenous people living downstream, and this was the first motivation for the Y Ikatu Xingu campaign--'save the good water of the Xingu'. Among the objectives of the initiative was to restore riparian forests on private land across the basin. For a region where the rivers, rainstorms, forest remnants, distances and farms are huge, the challenges were equally large: crossing the biotic and abiotic thresholds of degradation, as well as addressing the lack of technology, know-how, seeds, forest nurseries, trained personnel and roads, and the lack of motivation for restoration. After 6 years, despite the remarkable advances in terms of technical innovation coupled with a broad and effective social involvement, the restored areas represent only a small portion of those aimed for. The still high costs of restoration, the uncertainties of legislation and also the global economy have been strong forces constraining the expansion of restored forests. Additional efforts and strategies are necessary to overcome these barriers.

  2. Ecological restoration of Xingu Basin headwaters: motivations, engagement, challenges and perspectives

    PubMed Central

    Durigan, Giselda; Guerin, Natalia; da Costa, José Nicola Martorano Neves

    2013-01-01

    Over the past two decades, the headwaters of the Xingu Basin in the Amazon have been subjected to one of the highest deforestation rates in Brazil, with negative effects on both terrestrial and aquatic systems. The environmental consequences of forest land conversion have concerned the indigenous people living downstream, and this was the first motivation for the Y Ikatu Xingu campaign—‘save the good water of the Xingu’. Among the objectives of the initiative was to restore riparian forests on private land across the basin. For a region where the rivers, rainstorms, forest remnants, distances and farms are huge, the challenges were equally large: crossing the biotic and abiotic thresholds of degradation, as well as addressing the lack of technology, know-how, seeds, forest nurseries, trained personnel and roads, and the lack of motivation for restoration. After 6 years, despite the remarkable advances in terms of technical innovation coupled with a broad and effective social involvement, the restored areas represent only a small portion of those aimed for. The still high costs of restoration, the uncertainties of legislation and also the global economy have been strong forces constraining the expansion of restored forests. Additional efforts and strategies are necessary to overcome these barriers. PMID:23610171

  3. Spatio-temporal Variability of Controls on Water Balance Components in a Western Mountainous Headwater Basin

    NASA Astrophysics Data System (ADS)

    Kelleher, C.; Wagener, T.; McGlynn, B. L.; Marshall, L. A.; Jencso, K. G.

    2011-12-01

    Headwater basins represent a large portion of the stream network in the United States and provide crucial but largely unquantified ecosystem services, including export of water and nutrients to downstream sources and habitat for sensitive aquatic species. Investigating controls on hydrologic fluxes within these headwaters is important for understanding how these basins might respond to change in climate or land use. Our work focuses on characterizing controls on water balance components within the Tenderfoot Creek Experimental Forest (TCEF) via experimental data-modeling synthesis. Extensive monitoring within the basin offers the opportunity to compare model behavior against multiple water balance components and hydrologic fluxes, including snowmelt, snow water equivalent, evapotranspiration, catchment storage, and streamflow. We model the basin using the Distributed Hydrology Vegetation Soil Model (DHSVM) and apply variance-based global sensitivity analysis to quantify the spatio-temporal variability of controls on different hydrologic fluxes across the study domain. The results provide a unique opportunity for testing the consistency between DHSVM and our perception of the watershed processes in the TCEF.

  4. Life history characteristics and vital rates of Yellowstone Cutthroat Trout in two headwater basins

    USGS Publications Warehouse

    Uthe, Patrick; Al-Chokhachy, Robert K.; Zale, Alexander V.; Shepard, Bradley B.; McMahon, Thomas E.; Stephens, Tracy

    2016-01-01

    The Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri is native to the Rocky Mountains and has declined in abundance and distribution as a result of habitat degradation and introduced salmonid species. Many of its remaining strongholds are in headwater basins with minimal human disturbances. Understanding the life histories, vital rates, and behaviors of Yellowstone Cutthroat Trout within headwater stream networks remains limited yet is critical for effective management and conservation. We estimated annual relative growth in length and weight, annual survival rates, and movement patterns of Yellowstone Cutthroat Trout from three tributaries of Spread Creek, Wyoming, and two tributaries of Shields River, Montana, from 2011 through 2013 using PIT tag antennas within a mark–recapture framework. Mean annual growth rates varied among tributaries and size-classes, but were slow compared with populations of Yellowstone Cutthroat Trout from large, low-elevation streams. Survival rates were relatively high compared with those of other Cutthroat Trout subspecies, but we found an inverse relationship between survival and size, a pattern contrary to what has been reported for Cutthroat Trout in large streams. Mean annual survival rates ranged from 0.32 (SE = 0.04) to 0.68 (SE = 0.05) in the Spread Creek basin and from 0.30 (SE = 0.07) to 0.69 (SE = 0.10) in the Shields River basin. Downstream movements from tributaries were substantial, with as much as 26.5% of a tagging cohort leaving over the course of the study. Integrating our growth, survival, and movement results demonstrates the importance of considering strategies to enhance headwater stream habitats and highlights the importance of connectivity with larger stream networks.

  5. Hydrology of a wetland-dominated headwater basin in the Boreal Plain, Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Wells, Corey; Ketcheson, Scott; Price, Jonathan

    2017-04-01

    This study provides an in-depth analysis of the runoff generation dynamics and hydrological connectivity across upland-wetland transitions within a wetland-dominated headwater basin in the Western Boreal Plain (WBP), Canada. Basin runoff response between and among years was driven largely by differences in the timing and magnitude of precipitation relative to potential evapotranspiration, hence antecedent moisture conditions, which varied markedly over the four-year study (April-Sept). Runoff coefficients for individual precipitation events ranged from <1 to >90% depending on storm dynamics and antecedent conditions. Owing to its higher elevation, the basin received 55% more precipitation per month on average compared to 30-year climate normals and an average of 86 mm more precipitation per season than the nearby regional weather station. The wetland and adjacent forestlands became coupled during intermittent wet periods which generated substantial runoff. The findings of the current study suggest that, in contrast to conventional conceptual models, headwater catchments within the subhumid WBP have the capacity to generate significant runoff throughout the snow-free period. This has important implications for wetland maintenance and represents an important water delivery mechanism for downstream ecosystems where excess water is scarce.

  6. The size distribution of organic carbon in headwater streams in the Amazon basin.

    PubMed

    de Paula, Joana D'Arc; Luizão, Flávio Jesus; Piedade, Maria Teresa Fernandez

    2016-06-01

    Despite the strong representativeness of streams in the Amazon basin, their role in the accumulation of coarse particulate organic carbon (CPOC), fine particulate organic carbon (FPOC), and dissolved organic carbon (DOC) in transport, an important energy source in these environments, is poorly known. It is known that the arboreal vegetation in the Amazon basin is influenced by soil fertility and rainfall gradients, but would these gradients promote local differences in organic matter in headwater streams? To answer this question, 14 low-order streams were selected within these gradients along the Amazon basin, with extensions that varied between 4 and 8 km. The efficiency of the transformation of particulate into dissolved carbon fractions was assessed for each stream. The mean monthly benthic organic matter storage ranged between 1.58 and 9.40 t ha(-1) month(-1). In all locations, CPOC was the most abundant fraction in biomass, followed by FPOC and DOC. Rainfall and soil fertility influenced the distribution of the C fraction (p = 0.01), showing differentiated particulate organic carbon (POC) storage and DOC transportation along the basin. Furthermore, the results revealed that carbon quantification at the basin level could be underestimated, ultimately influencing the global carbon calculations for the region. This is especially due to the fact that the majority of studies consider only fine particulate organic matter and dissolved organic matter, which represent less than 50 % of the stored and transported carbon in streambeds.

  7. Towards Mapping the Provision of Ecosystem Services from Headwater Wetlands in the Susquehanna River Basin

    EPA Science Inventory

    Headwater wetlands provide a range of ecosystem services including habitat provisioning and flood retention. Following the River Ecosystem Synthesis framework we identified and assessed not only headwater wetlands, but unconstrained reaches with the potential to support diverse s...

  8. Assessment of climate change impacts on streamflow dynamics in the headwaters of the Amazon River basin

    NASA Astrophysics Data System (ADS)

    Yoon, Y.; Beighley, E.

    2015-12-01

    The Amazon River basin is the largest watershed in the world containing thousands of tributaries. Although the mainstream and its larger tributaries have been the focus on much research, there has been few studies focused on the hydrodynamics of smaller rivers in the foothills of the Andes Mountains. These smaller rivers are of particular importance for the fishery industry because fish migrate up these headwater rivers to spawn. During the rainy season, fish wait for storm event to increase water depths to a sufficient level for their passage. Understanding how streamflow dynamics will change in response to future conditions is vital for the sustainable management of the fishery industry. In this paper, we focus on improving the accuracy of river discharge estimates on relatively small-scale sub-catchments (100 ~ 40,000 km2) in the headwaters of the Amazon River basin. The Hillslope River Routing (HRR) hydrologic model and remotely sensed datasets are used. We provide annual runoff, seasonal patterns, and daily discharge characteristics for 81 known migration reaches. The model is calibrated for the period 2000-2014 and climate forecasts for the period 2070-2100 are used to assess future changes in streamflow dynamics. The forecasts for the 2070 to 2100 period were obtained by selecting 5 climate models from IPCC's Fifth Assessment Report (AR5) Coupled Model Intercomparison Project Phase 5 (CMIP5) based on their ability to represent the main aspects of recent (1970 to 2000) Amazon climate. The river network for the HRR model is developing using surface topography based on the SRTM digital elevation model. Key model forcings include precipitation (TRMM 3B42) and evapotranspiration (MODIS ET, MOD16). Model parameters for soil depth, hydraulic conductivity, runoff coefficients and lateral routing were initially approximated based on literature values and adjusted during calibration. Measurements from stream gauges located near the reaches of interest were used for

  9. Impact of Placer Mining on Sediment Transport in Headwaters of the Lake Baikal Basin.

    NASA Astrophysics Data System (ADS)

    Pietron, J.; Jarsjo, J.; Chalov, S.

    2015-12-01

    Adverse practices in alluvial surface mining (placer mining) can lead to shifts in sediment transport regimes of rivers. However, some placer mines are located in remote parts of river basins, which constrain data availability in mining impact assessments. One such mining area is the Zaamar Goldfield (Northern Mongolia) which stretches 60 km along the Tuul River. The area is located in the headwaters of the Lake Baikal Basin, and may impact the UNESCO World Heritage Site of Lake Baikal. Previous studies indicate that the mining industry in the Zaamar Goldfield loads the river system with considerable amount of contaminated sediments (heavy metals). Still, transport processes and possible changes in local to regional sediment transport need to be better understood. In this work, we use snapshot field measurements and various flow and transport modelling techniques to analyze (1) the impact of placer mining in the sediment delivery to the river system and (2) the dynamics of further sediment transport to downstream Tuul River. Our results indicate that surface mining operations and waste management have considerable impact on the sediment input from the landscape. Furthermore, dynamic in-channel storage of sediments can act as intermittent sources of mining sediments. These effects occur in addition to impacts of on-going changes in hydro-climatic conditions of the area. We hope that our methodology and results will aid in studying similar unmonitored and mining-affected river basins.

  10. Hydrological response to forest disturbance under a changing climate in experimental headwater basins, Central Sumava Mountains

    NASA Astrophysics Data System (ADS)

    Su, Ye; Gao, Hongkai; Langhammer, Jakub; Savenije, Hubert H. G.

    2014-05-01

    In forested basins, forest disturbance and climatic variability are commonly recognized as two major drivers of hydrological regimes changes. Vydra's mountainous headwater basin in the Czech Republic, which is selected as study area, has undergone simultaneously an increase in temperature and extensive forest disturbance mainly resulting from bark beetle outbreak. The study area consists of 8 small experimental sub-basins of size around 3-5 km2. Water stages have been monitored in 10-min interval since 2005. Data on precipitation, air temperature, radiation, air humidity, wind speed and direction exist at 10-minute interval, in 4 stations since 2009. Different sub-basins are covered by different types of physiographic conditions, land cover and varying intensity and nature of forest disturbance. A paired basin methodology was used to study the effect of land cover change on the runoff regime. In the studied basins, the cumulative effects of the changing climate and the extensive forest decay are reflected in the observed discharge data in terms of the seasonal shift in peak flow and low flow magnitude, frequency, and duration by statistical methods. From the basin comparison, we could identify which factors determine the differences in hydrological regimes adjustment. Two main conclusions can be drawn: 1) forest disturbance largely changes the interception and transpiration, and 2) paired basins method is able to trade time for space in understanding the process of forest degradation and regeneration, especially in the growing season. In winter the hydrological regime shifts were mainly driven by climate variability. Subsequently, we used this knowledge in hydrological models and tested our hypothesis by stepwise modelling. We assume that the topography and land cover have great influence on the hydrological regime under different climate conditions. Thus, we test the split-sample validation as well as model transferability within the framework of the FLEX

  11. Alternative sources of large seasonal ground-water supplies in the headwaters of the Susquehanna River basin, New York

    USGS Publications Warehouse

    Randall, A.D.; Snavely, D.S.; Holecek, T.P.; Waller, R.M.

    1988-01-01

    The northern divide of the Susquehanna River basin crosses 29 broad valleys that contain thick glacial deposits but are drained only by small headwater streams. Much groundwater could be withdrawn from sand and gravel deposits in these valleys with little immediate effect on streamflow. A digital model of the headwater reach of one typical valley suggests that pumping 10.8 million gal/day for 2 months every summer would lower the water table as much as 33 ft, cause the upper 1,900 ft of the stream draining the valley to go dry, and reduce streamflow downvalley by 1.2 million gal/day by the time pumping ceased. Saturated thickness of surficial sand and gravel exceeds 40 ft in about half the headwater valley reaches; the valley floor areas range from 0.2 to 9 sq mi. Seepage losses from small streams that carry runoff from adjacent till-covered uplands are a major source of recharge to aquifers in these valleys under natural conditions and would increase if the water table were lowered by seasonal withdrawals. Some aquifers beneath extensive clay layers in these and other valleys of the Susquehanna River basin may be partially independent of streams but not easily evaluated. (USGS)

  12. Distributed Application of the Unified Noah LSM with Hydrologic Flow Routing on an Appalachian Headwater Basin

    NASA Astrophysics Data System (ADS)

    Garcia, M.; Kumar, S.; Gochis, D.; Yates, D.; McHenry, J.; Burnet, T.; Coats, C.; Condrey, J.

    2006-05-01

    Collaboration between scientists at UMBC-GEST and NASA-GSFC, the NCAR Research Applications Laboratory (RAL), and Baron Advanced Meteorological Services (BAMS), has produced a modeling framework for the application of traditional land surface models (LSMs) in a distributed hydrologic system which can be used for diagnosis and prediction of routed stream discharge hydrographs. This collaboration is oriented on near-term system implementation across Romania for flood and flash-flood analyses and forecasting as part of the World Bank-funded Destructive Waters Abatement (DESWAT) program. Meteorological forcing from surface observations, model analyses and numerical forecasts are employed in the NASA-GSFC Land Information System (LIS) to drive the Unified Noah LSM with Noah-Distributed components, stream network delineation and routing schemes original to this work. The Unified Noah LSM is the outgrowth of a joint modeling effort between several research partners including NCAR, the NOAA National Center for Environmental Prediction (NCEP), and the Air Force Weather Agency (AFWA). At NCAR, hydrologically-oriented extensions to the Noah LSM have been developed for LSM applications in a distributed domain in order to address the lateral redistribution of soil moisture by surface and subsurface flow processes. These advancements have been integrated into the NASA-GSFC Land Information System (LIS) and coupled with an original framework for hydraulic channel network definition and specification, linkages with the Noah-Distributed overland and subsurface flow framework, and distributed cell- to-cell (or link-node) hydraulic routing. This poster presents an overview of the system components and their organization, as well as results of the first U.S. case study performed with this system under various configurations. The case study simulated precipitation events over a headwater basin in the southern Appalachian Mountains in October 2005 following the landfall of Tropical

  13. Pareiorhaphis vetula, a new armored catfish from the headwaters of the Rio Doce basin, Brazil (Siluriformes: Loricariidae).

    PubMed

    Pereira, Edson H L; Lehmann, Pablo A; Reis, Roberto E

    2016-07-28

    A new species of Pareiorhaphis is described from the upper Rio Doce basin. The description is based on a series of specimens recently collected in small headwater tributaries to the Rio Guanhães, a tributary of the Rio Santo Antonio, left bank of the Rio Doce in Minas Gerais State, eastern Brazil. Pareiorhaphis vetula, new species, is a small loricariid catfish with dark brown spots irregularly scattered over a brown background on the dorsal surface of body and along flanks. The new species differs from all other Pareiorhaphis species by having the maxillary barbel completely adnate to the lower lip and by adult males possessing a particularly elongate, sharply pointed, conical urogenital papilla. In addition, Pareiorhaphis vetula is further distinguished from most congeners by having a shorter pelvic-fin spine, or by possessing more numerous premaxillary teeth, and by lacking a dorsal-fin spinelet. A comparison with congeners P. nasuta, P. scutula and P. proskynita, which also occur in headwater streams of the Rio Doce basin is also presented.

  14. Assessment of climate impacts on hydrology and geomorphology of semiarid headwater basins using a physically-based model

    NASA Astrophysics Data System (ADS)

    Francipane, A.; Fatichi, S.; Ivanov, V. Y.; Noto, L. V.

    2013-12-01

    The response of watershed erosion rates to changes in climate is expected to be highly non-linear and thus demands for mechanistic approaches to improve our understanding of the underlying causes. In this study, the integrated geomorphic component tRIBS-Erosion of the physically-based, spatially distributed hydrological model, tRIBS, the TIN-based Real-time Integrated Basin Simulator, is used to analyze the sensitivity of small semi-arid headwater basins to projected climate conditions. Observed historic climate and downscaled realizations of general circulation models from CMIP3 inform the stochastic weather generator AWE-GEN (Advanced WEather GENerator), which is used to produce two climate ensembles representative of the past historic and future climate conditions for the Walnut Gulch Experimental Watershed (WGEW) area in the Southwest U.S. The former ensemble incorporates the stochastic variability of the observed climate, while the latter includes the stochastic variability and the uncertainty of CMIP3 multi-model climate change projections. The climate ensembles are used as forcing input to the hydrogeomorphic model that is applied to seven headwater basins of WGEW. The basin response in terms of runoff and sediment yield for climate ensembles representative of the historic past and future is simulated and probabilistic inferences on future changes in catchment runoff and sediment transport are drawn. The application of the model to multiple catchments also identifies the scaling relationship between specific sediment yield/runoff and drainage basin area. The study reveals that geomorphic differences among catchments influence the variability of sediment yield, as affected by possible future climates, much more as compared to runoff, which is instead strongly dominated by the climate forcing. Despite a large uncertainty inherent to climate change projections and imposed by the stochastic climate variability, the basin sediment yield is predicted to decrease

  15. Impacts of Climate Change on Groundwater Recharge and Streamflow in Headwater Catchments in the Yakima River Basin

    NASA Astrophysics Data System (ADS)

    Nguyen, T. T.; Adam, J. C.

    2015-12-01

    Headwater catchments are important sources of surface water supply, groundwater recharge and, thus, groundwater supply for agricultural activities in the Yakima River Basin (YRB, one of the most important agricultural basins in the western U.S). These catchments are, however, vulnerable to projected climate change in future decades, particularly if their runoff is dominated by snowmelt. The goal of this study is to assess the potential impacts of climate change on the temporal and spatial distributions of groundwater recharge and streamflow in three headwater catchments in the YRB. A Regional Hydro-Ecologic Simulation System ("RHESSys") is calibrated and evaluated with a global optimization tool ("Covariance Matrix Adaptation Evolution Strategy - CMA-ES") using 27 years of observation data from 1979 to 2005. Statistically downscaled climate projections for the 2050s from four global climate models driven by two different representative concentration pathways, RCP4.5 and RCP8.5 are used to predict future hydrologic changes. Our preliminary results show an increase in annual recharge between 2% and 13%, as well as in streamflow between 1% and 17%. Seasonal changes of recharge and streamflow are more pronounced with an increase up to 210% in winters and a decrease as high as 60% in summers in the 2050s. Both recharge and streamflow projections indicate timing shifts in all three catchments. The outcome from this study will be an integral part of a future study which investigates the impacts of climate change on surface water vulnerability due to supplemental pumping, potential recharge changes and related surface-groundwater interactions in the YRB using an integrated modeling approach that consists of three models: RHESSys, a groundwater model (MODFLOW) and a river and reservoir management model (RiverWare).

  16. Spatial and temporal patterns of stream burial and its effect on habitat connectivity across headwater stream communities of the Potomac River Basin, USA

    NASA Astrophysics Data System (ADS)

    Weitzell, R.; Guinn, S. M.; Elmore, A. J.

    2012-12-01

    The process of directing streams into culverts, pipes, or concrete-lined ditches during urbanization, known as stream burial, alters the primary physical, chemical, and biological processes of streams. Knowledge of the cumulative impacts of reduced structure and ecological function within buried stream networks is crucial for informing management of stream ecosystems, in light of continued growth in urban areas, and the uncertain response of freshwater ecosystems to the stresses of global climate change. To address this need, we utilized recently improved stream maps for the Potomac River Basin (PRB) to describe the extent and severity of stream burial across the basin. Observations of stream burial made from high resolution aerial photographs (>1% of total basin area) and a decision tree using spatial statistics from impervious cover data were used to predict stream burial at 4 time-steps (1975, 1990, 2001, 2006). Of the roughly 95,500 kilometers (km) of stream in the PRB, approximately 4551 km (4.76%) were buried by urban development as of 2001. Analysis of county-level burial trends shows differential patterns in the timing and rates of headwater stream burial, which may be due to local development policies, topographical constraints, and/or time since development. Consistently higher rates of stream burial were observed for small streams, decreasing with stream order. Headwater streams (1st-2nd order) are disproportionately affected, with burial rates continuing to increase over time in relation to larger stream orders. Beyond simple habitat loss, headwater burial decreases connectivity among headwater populations and habitats, with potential to affect a wide range of important ecological processes. To quantify changes to regional headwater connectivity we applied a connectivity model based on electrical circuit theory. Circuit-theoretical models function by treating the landscape as a resistance surface, representing hypothesized relationships between

  17. Hydrological Impacts of Land Use Change and Climate Variability in the Headwater Region of the Heihe River Basin, Northwest China.

    PubMed

    Zhang, Ling; Nan, Zhuotong; Xu, Yi; Li, Shuo

    2016-01-01

    Land use change and climate variability are two key factors impacting watershed hydrology, which is strongly related to the availability of water resources and the sustainability of local ecosystems. This study assessed separate and combined hydrological impacts of land use change and climate variability in the headwater region of a typical arid inland river basin, known as the Heihe River Basin, northwest China, in the recent past (1995-2014) and near future (2015-2024), by combining two land use models (i.e., Markov chain model and Dyna-CLUE) with a hydrological model (i.e., SWAT). The potential impacts in the near future were explored using projected land use patterns and hypothetical climate scenarios established on the basis of analyzing long-term climatic observations. Land use changes in the recent past are dominated by the expansion of grassland and a decrease in farmland; meanwhile the climate develops with a wetting and warming trend. Land use changes in this period induce slight reductions in surface runoff, groundwater discharge and streamflow whereas climate changes produce pronounced increases in them. The joint hydrological impacts are similar to those solely induced by climate changes. Spatially, both the effects of land use change and climate variability vary with the sub-basin. The influences of land use changes are more identifiable in some sub-basins, compared with the basin-wide impacts. In the near future, climate changes tend to affect the hydrological regimes much more prominently than land use changes, leading to significant increases in all hydrological components. Nevertheless, the role of land use change should not be overlooked, especially if the climate becomes drier in the future, as in this case it may magnify the hydrological responses.

  18. Hydrological Impacts of Land Use Change and Climate Variability in the Headwater Region of the Heihe River Basin, Northwest China

    PubMed Central

    Zhang, Ling; Nan, Zhuotong; Xu, Yi; Li, Shuo

    2016-01-01

    Land use change and climate variability are two key factors impacting watershed hydrology, which is strongly related to the availability of water resources and the sustainability of local ecosystems. This study assessed separate and combined hydrological impacts of land use change and climate variability in the headwater region of a typical arid inland river basin, known as the Heihe River Basin, northwest China, in the recent past (1995–2014) and near future (2015–2024), by combining two land use models (i.e., Markov chain model and Dyna-CLUE) with a hydrological model (i.e., SWAT). The potential impacts in the near future were explored using projected land use patterns and hypothetical climate scenarios established on the basis of analyzing long-term climatic observations. Land use changes in the recent past are dominated by the expansion of grassland and a decrease in farmland; meanwhile the climate develops with a wetting and warming trend. Land use changes in this period induce slight reductions in surface runoff, groundwater discharge and streamflow whereas climate changes produce pronounced increases in them. The joint hydrological impacts are similar to those solely induced by climate changes. Spatially, both the effects of land use change and climate variability vary with the sub-basin. The influences of land use changes are more identifiable in some sub-basins, compared with the basin-wide impacts. In the near future, climate changes tend to affect the hydrological regimes much more prominently than land use changes, leading to significant increases in all hydrological components. Nevertheless, the role of land use change should not be overlooked, especially if the climate becomes drier in the future, as in this case it may magnify the hydrological responses. PMID:27348224

  19. Stochastic assessment of climate impacts on hydrology and geomorphology of semiarid headwater basins using a physically based model

    NASA Astrophysics Data System (ADS)

    Francipane, A.; Fatichi, S.; Ivanov, V. Y.; Noto, L. V.

    2015-03-01

    Hydrologic and geomorphic responses of watersheds to changes in climate are difficult to assess due to projection uncertainties and nonlinearity of the processes that are involved. Yet such assessments are increasingly needed and call for mechanistic approaches within a probabilistic framework. This study employs an integrated hydrology-geomorphology model, the Triangulated Irregular Network-based Real-time Integrated Basin Simulator (tRIBS)-Erosion, to analyze runoff and erosion sensitivity of seven semiarid headwater basins to projected climate conditions. The Advanced Weather Generator is used to produce two climate ensembles representative of the historic and future climate conditions for the Walnut Gulch Experimental Watershed located in the southwest U.S. The former ensemble incorporates the stochastic variability of the observed climate, while the latter includes the stochastic variability and the uncertainty of multimodel climate change projections. The ensembles are used as forcing for tRIBS-Erosion that simulates runoff and sediment basin responses leading to probabilistic inferences of future changes. The results show that annual precipitation for the area is generally expected to decrease in the future, with lower hourly intensities and similar daily rates. The smaller hourly rainfall generally results in lower mean annual runoff. However, a non-negligible probability of runoff increase in the future is identified, resulting from stochastic combinations of years with low and high runoff. On average, the magnitudes of mean and extreme events of sediment yield are expected to decrease with a very high probability. Importantly, the projected variability of annual sediment transport for the future conditions is comparable to that for the historic conditions, despite the fact that the former account for a much wider range of possible climate "alternatives." This result demonstrates that the historic natural climate variability of sediment yield is already so

  20. Relationship Between Storm Hydrograph Components and Subsurface Flow Processes in a Hilly Headwater Basin, Toyota, Japan

    NASA Astrophysics Data System (ADS)

    Tsujimura, M.; Asai, K.; Takei, R.

    2001-05-01

    Temporal and spatial distribution of tracer elements and subsurface flow processes were investigated to study relationship between storm hydrograph components and behavior of subsurface water in a headwater catchment of Toyota Hill, Aichi prefecture, central Japan. The catchment has an area of 0.857 ha with an altitude of 60 to 100 m, and is underlain by granite. The soil depth revealed by sounding test ranges from 0.5 to 4.0 m. Rain, stream, soil and ground waters were sampled once in a week, and the stream water was sampled at 5 to 60 minute intervals during rainstorms. The pressure head of subsurface water was monitored using tensiometers and piezometers nests, and the stream flow was monitored using V-notch weir. The stable isotopic ratios of deuterium and oxygen 18 and inorganic ion concentrations were determined on all water samples. The oxygen 18 isotopic ratio in stream water decreased with rainfall during the rainstorms. The ratio of event water component to the total runoff water at the peak discharge ranged from 16 to 92 %, and the event water ratio correlated with the peak discharge rate and rainfall intensity. The tesiometric data showed that the shallow subsurface water with low isotopic ratios at the lower slope discharged directly to the stream during the heavy rainstorms. The shallow subsurface flow at the lower slope and overland flow on the raiparian zone contributed much to the stream water chemistry during heavy rainstorms.

  1. The Quantification and Identification of Land Use Change Impacts to Hydrology in Brazil from Headwater to Large Basin Scales

    NASA Astrophysics Data System (ADS)

    Levy, M. C.; Lopes, A. V.; Cohn, A.; Thompson, S. E.

    2015-12-01

    Rapid agricultural expansion and intensification has characterized the land use/cover change (LUCC) dynamics of a large region spanning the southern rainforest and savanna biomes of Brazil. Despite a plethora of modeling analyses and small-scale investigations, the cumulative effects of this transformation on hydrological processes at multiple scales remain unclear. Yet quantifying the links between LUCC and hydrological response is essential to support evidence-based sustainable development of industry, society, and environment, particularly in this region, which includes the headwaters of Brazil's major rivers, the climatically-crucial Amazon transition region, and Brazil's agricultural breadbasket. Empirical analyses that can inform land use policy in this region and are sensitive to climate, agriculture and hydrological outcomes are critically needed. This study leverages the increased availability of remotely-sensed data products and a spatially dispersed gauging network to investigate the effects of a decade of LUCC on streamflow in over 150 river basins. Using a collection of statistical techniques to identify causal relationships and isolate LUCC effects from confounding variables such as climate, we quantify the sensitivity of hydrological dynamics to LUCC from small watersheds to regional scales.

  2. Land use effects on quality and quantity aspects of water resources in headwater areas of the Jaguari River Basin

    NASA Astrophysics Data System (ADS)

    Figueiredo, R. D. O.; Camargo, P. B. D.; Piccolo, M. C.; Zuccari, M. L.; Ferracini, V. L.; Cruz, P. P. N. D.; Green, T. R.; Costa, C. F. G. D.; Reis, L. D. C.

    2015-12-01

    In the context of the recent drought conditions in southeastern Brazil, EMBRAPA (Brazilian Agricultural Research Corporation) in partnership with two Brazilian universities (USP/CENA and UNIFAL) planned a research project, called BaCaJa, to understand the hydrobiogeochemistry processes that occur in small catchments (<1,000 ha) at the upper portions of the Jaguari River Basin situated on both states of Sao Paulo and Minas Gerais. The approach of this study is based on the fact that the evaluation of stream water quality and quantity is an efficient tool to characterize the sustainability of the agriculture production at a catchment level. Its goal is, therefore, to survey the land use effects on the hydrobiogeochemistry in headwaters areas of the Jaguari River Basin to support sustainable management of water resources in this region. Sampling stations were established on rivers and streams ranging from one to five order channels as well as selected small catchments to conduct studies on overland flow, soil solution, soil quality, aquatic biota and pesticide dynamic. The research team is huge and their goals are specific, diverse and complementary, being summed up as: characterize land use, topography and soils; evaluate erosive potential in agriculture areas; measure soil carbon and nitrogen contents; characterize hydrogeochemistry fluxes; apply hydrological modeling and simulate different land use and management scenarios; monitor possible pesticides contamination; and survey macro invertebrates as indicators of water quality. Based on a synthesis of the results, the project team intends to point out the environmental impacts and contribute recommendations of management for the focused region to conserve water resources in terms of quality and quantity.

  3. Effects of groundwater levels and headwater wetlands on streamflow in the Charlie Creek basin, Peace River watershed, west-central Florida

    USGS Publications Warehouse

    Lee, T.M.; Sacks, L.A.; Hughes, J.D.

    2010-01-01

    The Charlie Creek basin was studied from April 2004 to December 2005 to better understand how groundwater levels in the underlying aquifers and storage and overflow of water from headwater wetlands preserve the streamflows exiting this least-developed tributary basin of the Peace River watershed. The hydrogeologic framework, physical characteristics, and streamflow were described and quantified for five subbasins of the 330-square mile Charlie Creek basin, allowing the contribution of its headwaters area and tributary subbasins to be separately quantified. A MIKE SHE model simulation of the integrated surface-water and groundwater flow processes in the basin was used to simulate daily streamflow observed over 21 months in 2004 and 2005 at five streamflow stations, and to quantify the monthly and annual water budgets for the five subbasins including the changing amount of water stored in wetlands. Groundwater heads were mapped in Zone 2 of the intermediate aquifer system and in the Upper Floridan aquifer, and were used to interpret the location of artesian head conditions in the Charlie Creek basin and its relation to streamflow. Artesian conditions in the intermediate aquifer system induce upward groundwater flow into the surficial aquifer and help sustain base flow which supplies about two-thirds of the streamflow from the Charlie Creek basin. Seepage measurements confirmed seepage inflow to Charlie Creek during the study period. The upper half of the basin, comprised largely of the Upper Charlie Creek subbasin, has lower runoff potential than the lower basin, more storage of runoff in wetlands, and periodically generates no streamflow. Artesian head conditions in the intermediate aquifer system were widespread in the upper half of the Charlie Creek basin, preventing downward leakage from expansive areas of wetlands and enabling them to act as headwaters to Charlie Creek once their storage requirements were met. Currently, the dynamic balance between wetland

  4. Using a physically-based model, tRIBS-Erosion, for investigating the effects of climate change in semi-arid headwater basins.

    NASA Astrophysics Data System (ADS)

    Francipane, Antonio; Fatichi, Simone; Ivanov, Valeriy Y.; Noto, Leonardo V.

    2013-04-01

    Soil erosion due to rainfall detachment and flow entrainment of soil particles is a physical process responsible for a continuous evolution of landscapes. The rate and spatial distribution of this phenomenon depend on several factors such as climate, hydrologic regime, geomorphic characteristics, and vegetation of a basin. Many studies have demonstrated that climate-erosion linkage in particular influences basin sediment yield and landscape morphology. Although soil erosion rates are expected to change in response to climate, these changes can be highly non-linear and thus require mechanistic understanding of underlying causes. In this study, an integrated geomorphic component of the physically-based, spatially distributed hydrological model, tRIBS, the TIN-based Real-time Integrated Basin Simulator, is used to analyze the sensitivity of semi-arid headwater basins to climate change. Downscaled outputs of global circulation models are used to inform a stochastic weather generator that produces an ensemble of climate scenarios for an area in the Southwest U.S. The ensemble is used as input to the integrated model that is applied to different headwater basins of the Walnut Gulch Experimental Watershed to understand basin response to climate change in terms of runoff and sediment yield. Through a model application to multiple catchments, a scaling relationship between specific sediment yield and drainage basin area is also addressed and probabilistic inferences on future changes in catchment runoff and yield are drawn. Geomorphological differences among catchments do not influence specific changes in runoff and sediment transport that are mostly determined by precipitation changes. Despite a large uncertainty dictated by climate change projections and stochastic variability, sediment transport is predicted to decrease despite a non-negligible possibility of larger runoff rates.

  5. Sediment Delivery Ratio of Single Flood Events and the Influencing Factors in a Headwater Basin of the Chinese Loess Plateau

    PubMed Central

    Zheng, Mingguo; Liao, Yishan; He, Jijun

    2014-01-01

    Little is known about the sediment delivery of single flood events although it has been well known that the sediment delivery ratio at the inter-annual time scale is close to 1 in the Chinese Loess Plateau. This study examined the sediment delivery of single flood events and the influencing factors in a headwater basin of the Loess Plateau, where hyperconcentrated flows are dominant. Data observed from plot to subwatershed over the period from 1959 to 1969 were presented. Sediment delivery ratio of a single event (SDRe) was calculated as the ratio of sediment output from the subwatershed to sediment input into the channel. It was found that SDRe varies greatly for small events (runoff depth <5 mm or rainfall depth <30 mm) and remains fairly constant (approximately between 1.1 and 1.3) for large events (runoff depth >5 mm or rainfall depth >30 mm). We examined 11 factors of rainfall (rainfall amount, rainfall intensity, rainfall kinetic energy, rainfall erosivity and rainfall duration), flood (area-specific sediment yield, runoff depth, peak flow discharge, peak sediment concentration and flood duration) and antecedent land surface (antecedent precipitation) in relation to SDRe. Only the peak sediment concentration significantly correlates with SDRe. Contrary to popular belief, channel scour tends to occur in cases of higher peak sediment concentrations. Because small events also have chances to attain a high sediment concentration, many small events (rainfall depth <20 mm) are characterized by channel scour with an SDRe larger than 1. Such observations can be related to hyperconcentrated flows, which behave quite differently from normal stream flows. Our finding that large events have a nearly constant SDRe is useful for sediment yield predictions in the Loess Plateau and other regions where hyperconcentrated flows are well developed. PMID:25389752

  6. Long-term trends in stream water and precipitation chemistry at five headwater basins in the northeastern United States

    USGS Publications Warehouse

    Clow, David W.; Mast, M. Alisa

    1999-01-01

    Stream water data from five headwater basins in the northeastern United States covering water years 1968-1996 and precipitation data from eight nearby precipitation monitoring sites covering water years 1984-1996 were analyzed for temporal trends in chemistry using the nonparametric seasonal Kendall test. Concentrations of SO4 declined at three of five streams during 1968,1996 (p < 0.1), and all of the streams exhibited downward trends in SO4 over the second half of the period (1984-1996). Concentrations of SO4 in precipitation declined at seven of eight sites from 1984 to 1996, and the magnitudes of the declines (-0.7 to -2.0 ??eq L-1 yr-1) generally were similar to those of stream water SO4. These results indicate that changes in precipitation SO4 were of sufficient magnitude to account for changes in stream water SO4. Concentrations of Ca + Mg declined at three of five streams and five of eight precipitation sites from 1984 to 1996. Precipitation acidity decreased at five of eight sites during the same period, but alkalinity increased in only one stream. In most cases the decreases in stream water SO4 were similar in magnitude to declines in stream water Ca + Mg, which is consistent with the theory of leaching by mobile acid anions in soils. In precipitation the magnitudes of SO4 declines were similar to those of hydrogen, and declines in Ca + Mg were much smaller. This indicates that recent decreases in SO4 deposition are now being reflected in reduced precipitation acidity. The lack of widespread increases in stream water alkalinity, despite the prevalence of downward trends in Stream water SO4, suggests that at most sites, increases in stream water pH and acid-neutralizing capacity may be delayed until higher soil base-saturation levels are achieved.

  7. Sediment delivery ratio of single flood events and the influencing factors in a headwater basin of the Chinese Loess Plateau.

    PubMed

    Zheng, Mingguo; Liao, Yishan; He, Jijun

    2014-01-01

    Little is known about the sediment delivery of single flood events although it has been well known that the sediment delivery ratio at the inter-annual time scale is close to 1 in the Chinese Loess Plateau. This study examined the sediment delivery of single flood events and the influencing factors in a headwater basin of the Loess Plateau, where hyperconcentrated flows are dominant. Data observed from plot to subwatershed over the period from 1959 to 1969 were presented. Sediment delivery ratio of a single event (SDRe) was calculated as the ratio of sediment output from the subwatershed to sediment input into the channel. It was found that SDRe varies greatly for small events (runoff depth <5 mm or rainfall depth <30 mm) and remains fairly constant (approximately between 1.1 and 1.3) for large events (runoff depth >5 mm or rainfall depth >30 mm). We examined 11 factors of rainfall (rainfall amount, rainfall intensity, rainfall kinetic energy, rainfall erosivity and rainfall duration), flood (area-specific sediment yield, runoff depth, peak flow discharge, peak sediment concentration and flood duration) and antecedent land surface (antecedent precipitation) in relation to SDRe. Only the peak sediment concentration significantly correlates with SDRe. Contrary to popular belief, channel scour tends to occur in cases of higher peak sediment concentrations. Because small events also have chances to attain a high sediment concentration, many small events (rainfall depth <20 mm) are characterized by channel scour with an SDRe larger than 1. Such observations can be related to hyperconcentrated flows, which behave quite differently from normal stream flows. Our finding that large events have a nearly constant SDRe is useful for sediment yield predictions in the Loess Plateau and other regions where hyperconcentrated flows are well developed.

  8. Hydrologic analysis of two headwater lake basins of differing lake pH in the west-central Adirondack Mountains of New York

    USGS Publications Warehouse

    Murdoch, Peter S.; Peters, N.E.; Newton, R.M.

    1987-01-01

    Hydrologic analysis of two headwater lake basins in the Adirondack Mountains, New York, during 1980-81 indicates that the degree of neutralization of acid precipitation is controlled by the groundwater contribution to the lake. According to flow-duration analyses, daily mean outflow/unit area from the neutral lake (Panther Lake, pH 5-7) was more sustained and contained a higher percentage of groundwater than that of the acidic lake (Woods Lake, pH 4-5). Outflow recession rates and maximum base-flow rates, derived from individual recession curves, were 3.9 times and 1.5 times greater, respectively, in the neutral-lake basin than in the acidic-lake basin. Groundwater contribution to lake outflow was also calculated from a lake-water budget; the groundwater contribution to the neutral lake was about 10 times greater than that to the acidic lake. Thick sandy till forms the groundwater reservoir and the major recharge area in both basins but covers 8.5 times more area in the neutral-lake basin than in the acidic-lake basin. More groundwater storage within the neutral basin provides longer contact time with neutralizing minerals and more groundwater discharge. As a result, the neutral lake has relatively high pH and alkalinity, and more net cation transport. (USGS)

  9. Ecohydrological implications of runoff harvesting in the headwaters of the Thukela River basin, South Africa

    NASA Astrophysics Data System (ADS)

    De Winnaar, Gary; Jewitt, Graham

    Hydrological regimes have an important influence on biodiversity, structure, and functioning of aquatic ecosystems. Unforeseen circumstances, both hydrologically and ecologically, caused by potential adoption and expansion of runoff harvesting innovations is of particular concern to water resource planners, as downstream river systems are likely to be adversely affected. This paper provides methods for determining the influence that large-scale adoption of runoff harvesting could have on downstream flow regimes by using a scenario-based approach, with the ACRU Agrohydrological model, to simulate the potential alteration of streamflow regimes due to runoff harvesting. Scenarios were based entirely on the spatial extent of impervious surfaces associated with rural homesteads, estimates of which were taken from current population data and used to establish the density of hypothetical runoff harvesting systems within a catchment setup. Daily streamflow simulation from nine Quaternary Catchments in the Thukela River basin provided suitable data series’ for analysis using the Indicators of Hydrological Alteration method to compute ecologically relevant hydrological parameters. The outcome of this ecohydrological study demonstrated that a relatively simple modelling exercise offers the potential to assess impacts that may arise from large-scale runoff harvesting. Results established that magnitudes of high and low flows of river flow regimes were most affected by runoff harvesting. Flow reduction was found to be most significant with low flows (up to 29%) in the case where the maximum runoff harvesting scenario was used. However, the majority of the IHA hydrological flow parameters revealed only slight impacts, even under circumstances where modelling scenarios were based on unrealistically high proportions of runoff harvesting. Increasing the spatial extent of runoff harvesting is thus expected to have a much greater impact at smaller spatial scales; water resources of

  10. Direct measurements of bed sediment entrainment and basal stress from the headwaters of a natural debris-flow basin

    NASA Astrophysics Data System (ADS)

    McCoy, S. W.; Kean, J. W.; Coe, J. A.; Tucker, G. E.; Staley, D. M.; Wasklewicz, T. A.

    2010-12-01

    When mixtures of soil, rock and water flow down slope as a debris flow they can entrain and transport large amounts of bed sediment and erode underlying bedrock. Although sediment entrainment and bedrock scour by debris flows are commonplace in steep terrain, there are few measurements to constrain key terms in event-scale debris-flow routing models or longer-term landscape evolution models that include the effects of bedrock erosion by debris-flows. Particularly conspicuous are the lack of bed sediment entrainment measurements and measurements of the evolving stress state at the flow-bedrock interface as the shielding layer of sediment is removed and sediment entrainment gives way to bedrock erosion. Here we present data from the headwaters of a debris-flow basin at Chalk Cliffs, Colorado, where we directly measured entrainment of channel sediment and the evolving stress state at the bedrock interface during three debris-flow events. We made these measurements through the combined the use of a novel sediment entrainment sensor and a force plate with more commonly used video imagery and instrumentation, to measure pore-fluid pressure, flow stage, soil moisture, and rainfall during the three debris-flow events. We extended these at-a-point process measurements to evaluate the reach-scale response using pre- and post-event terrestrial laser scans. During the three separate debris-flow events approximately 1.1 m, 0.5 m, and 0.4 m of unconsolidated bed sediment were entrained. Following entrainment of the sediment, bedrock was scoured by flows that ranged from water-poor coarse-grained surge fronts to water-rich turbulent flows with vigorous bedload transport. In all cases, entrainment of bed sediment was progressive, rather than by a single en masse failure of the sediment at the sediment-bedrock interface. The measured rates were dependent on bed sediment water content. When the bed sediment was unsaturated, entrainment was relatively slow, generally taking several

  11. Quantification of surface water and groundwater flows to open- and closed-basin lakes in a headwaters watershed using a descriptive oxygen stable isotope model

    USGS Publications Warehouse

    Stets, Edward G.; Winter, T. C.; Rosenberry, Donald O.; Striegl, Robert G.

    2010-01-01

    Accurate quantification of hydrologic fluxes in lakes is important to resource management and for placing hydrologic solute flux in an appropriate biogeochemical context. Water stable isotopes can be used to describe water movements, but they are typically only effective in lakes with long water residence times. We developed a descriptive time series model of lake surface water oxygen-18 stable isotope signature (δL) that was equally useful in open- and closed-basin lakes with very different hydrologic residence times. The model was applied to six lakes, including two closed-basin lakes and four lakes arranged in a chain connected by a river, located in a headwaters watershed. Groundwater discharge was calculated by manual optimization, and other hydrologic flows were constrained by measured values including precipitation, evaporation, and streamflow at several stream gages. Modeled and observed δL were highly correlated in all lakes (r = 0.84–0.98), suggesting that the model adequately described δL in these lakes. Average modeled stream discharge at two points along the river, 16,000 and 11,800 m3 d−1, compares favorably with synoptic measurement of stream discharge at these sites, 17,600 and 13,700 m3 d−1, respectively. Water yields in this watershed were much higher, 0.23–0.45 m, than water yields calculated from gaged streamflow in regional rivers, approximately 0.10 m, suggesting that regional groundwater discharge supports water flux through these headwaters lakes. Sensitivity and robustness analyses also emphasized the importance of considering hydrologic residence time when designing a sampling protocol for stable isotope use in lake hydrology studies.

  12. Quantification of surface water and groundwater flows to open - and closed-basin lakes in a headwaters watershed using a descriptive oxygen stable isotope model

    USGS Publications Warehouse

    Stets, E.G.; Winter, T.C.; Rosenberry, D.O.; Striegl, R.G.

    2010-01-01

    Accurate quantification of hydrologic fluxes in lakes is important to resource management and for placing hydrologic solute flux in an appropriate biogeochemical context. Water stable isotopes can be used to describe water movements, but they are typically only effective in lakes with long water residence times. We developed a descriptive time series model of lake surface water oxygen-18 stable isotope signature (??L) that was equally useful in open- and closed-basin lakes with very different hydrologic residence times. The model was applied to six lakes, including two closed-basin lakes and four lakes arranged in a chain connected by a river, located in a headwaters watershed. Groundwater discharge was calculated by manual optimization, and other hydrologic flows were constrained by measured values including precipitation, evaporation, and streamflow at several stream gages. Modeled and observed ??L were highly correlated in all lakes (r = 0.84-0.98), suggesting that the model adequately described ??L in these lakes. Average modeled stream discharge at two points along the river, 16,000 and 11,800 m3 d -1, compares favorably with synoptic measurement of stream discharge at these sites, 17,600 and 13,700 m3 d-1, respectively. Water yields in this watershed were much higher, 0.23-0.45 m, than water yields calculated from gaged streamflow in regional rivers, approximately 0.10 m, suggesting that regional groundwater discharge supports water flux through these headwaters lakes. Sensitivity and robustness analyses also emphasized the importance of considering hydrologic residence time when designing a sampling protocol for stable isotope use in lake hydrology studies. Copyright 2010 by the American Geophysical Union.

  13. Headwater valley response to climate and land use changes during the Little Ice Age in the Massif Central (Yzeron basin, France)

    NASA Astrophysics Data System (ADS)

    Delile, Hugo; Schmitt, Laurent; Jacob-Rousseau, Nicolas; Grosprêtre, Loïc; Privolt, Grégoire; Preusser, Frank

    2016-03-01

    The geomorphological response of valley bottoms in eastern France to climatic fluctuations of the Little Ice Age (LIA) was investigated using sedimentological analysis together with optically stimulated luminescence (OSL) and radiocarbon dating. Diachronic mapping of land use since the beginning of the nineteenth century was also carried out. Since A.D. 1500, the valley bottoms experienced three cycles of aggradation and subsequent incision, each characterized by paired periods of high and low detritic activity. While the impact of human activity on the aggradation of the alluvial plain is observed, the vertical dynamics of the valley bottom deposits seemingly were also linked to the hydroclimatic fluctuations during the LIA. The sensitivity to these fluctuations was increased by human activity at the scale of the basin. Variations of the winter North Atlantic Oscillation (NAO) and solar activity from the last five centuries correlate with wet and cold phases during which valley bottoms accumulated, and dry and warm phases during which the streams incised into the valley floors. This fluvial sensitivity to the meteorological conditions induced temporal variations in sedimentary supply originating from either direct input from remnants of periglacial alluvial sheets or local rocky outcrops and/or from indirect input from the erosion of alluvial and colluvial deposits. These two components, combined with the sheet runoff over the ploughlands, express the complex coupling between hillslopes and valley bottoms in the headwater catchments. This caused a cascade-shaped transit of the sediments characterized by alternating phases of storage and removal.

  14. Two new species of Hyphessobrycon (Characiformes: Characidae) from the headwaters of the Tapajós and Xingu River basins, Pará, Brazil.

    PubMed

    Teixeira, T F; Netto-Ferreira, A L; Birindelli, J L O; Sousa, L M

    2016-02-01

    Two new species of Hyphessobrycon are described from the headwaters of the Tapajós and Xingu River basins, Pará, Brazil. Both new species can be distinguished from congeners by the presence of a vertically elongate humeral blotch, a conspicuous round to vertically oblong caudal-peduncle blotch not extending onto the distal portions of the middle caudal-fin rays, a conspicuous blotch on the central portion of the third infraorbital immediately ventral to the eye, the lack of a conspicuous longitudinal stripe and the lack of sexual dimorphism in the extension of the caudal-peduncle blotch. Hyphessobrycon delimai n. sp. can be distinguished from Hyphessobrycon krenakore n. sp. by the extent of the caudal-peduncle blotch which extends across most of the caudal-peduncle depth (v. restricted to the middle portion of the caudal peduncle), the presence of dark chromatophores uniformly scattered along the length of the interradial membranes of the dorsal, anal and caudal fins (v. concentrated on the distal one-half or one-fourth of the interradial membranes) and the absence of small bony processes on the pelvic and anal fins of mature males (v. small bony processes present).

  15. Occurrence and distribution of dissolved solids, selenium, and uranium in groundwater and surface water in the Arkansas River Basin from the headwaters to Coolidge, Kansas, 1970-2009

    USGS Publications Warehouse

    Miller, Lisa D.; Watts, Kenneth R.; Ortiz, Roderick F.; ,

    2010-01-01

    In 2007, the U.S. Geological Survey (USGS), in cooperation with City of Aurora, Colorado Springs Utilities, Colorado Water Conservation Board, Lower Arkansas Valley Water Conservancy District, Pueblo Board of Water Works, Southeastern Colorado Water Activity Enterprise, Southeastern Colorado Water Conservancy District, and Upper Arkansas Water Conservancy District began a retrospective evaluation to characterize the occurrence and distribution of dissolved-solids (DS), selenium, and uranium concentrations in groundwater and surface water in the Arkansas River Basin based on available water-quality data collected by several agencies. This report summarizes and characterizes available DS, dissolved-selenium, and dissolved-uranium concentrations in groundwater and surface water for 1970-2009 and describes DS, dissolved-selenium, and dissolved-uranium loads in surface water along the main-stem Arkansas River and selected tributary and diversion sites from the headwaters near Leadville, Colorado, to the USGS 07137500 Arkansas River near Coolidge, Kansas (Ark Coolidge), streamgage, a drainage area of 25,410 square miles. Dissolved-solids concentrations varied spatially in groundwater and surface water in the Arkansas River Basin. Dissolved-solids concentrations in groundwater from Quaternary alluvial, glacial drift, and wind-laid deposits (HSU 1) increased downgradient with median values of about 220 mg/L in the Upper Arkansas subbasin (Arkansas River Basin from the headwaters to Pueblo Reservoir) to about 3,400 mg/L in the Lower Arkansas subbasin (Arkansas River Basin from John Martin Reservoir to Ark Coolidge). Dissolved-solids concentrations in the Arkansas River also increased substantially in the downstream direction between the USGS 07086000 Arkansas River at Granite, Colorado (Ark Granite), and Ark Coolidge streamgages. Based on periodic data collected from 1976-2007, median DS concentrations in the Arkansas River ranged from about 64 mg/L at Ark Granite to about

  16. Multi-variable evaluation of hydrological model predictions for a headwater basin in the Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Fang, X.; Pomeroy, J. W.; Ellis, C. R.; MacDonald, M. K.; DeBeer, C. M.; Brown, T.

    2012-11-01

    One of the purposes of the Cold Regions Hydrological Modelling platform (CRHM) is to diagnose inadequacies in the understanding of the hydrological cycle and its simulation. A physically based hydrological model including a full suite of snow and cold regions hydrology processes as well as warm season, hillslope and groundwater hydrology was developed in CRHM for application in the Marmot Creek Research Basin (~ 9.4km2), located in the Front Ranges of Canadian Rocky Mountains. Parameters were selected from digital elevation model, forest, soil and geological maps, and from the results of many cold regions hydrology studies in the region and elsewhere. Non-calibrated simulations were conducted for six hydrological years during 2005-2011 and were compared with detailed field observations of several hydrological cycle components. Results showed good model performance for snow accumulation and snowmelt compared to the field observations for four seasons during 2007-2011, with a small bias and normalized root mean square difference (NRMSD) ranging from 40 to 42% for the subalpine conifer forests and from 31 to 67% for the alpine tundra and tree-line larch forest environments. Overestimation or underestimation of the peak SWE ranged from 1.6 to 29%. Simulations matched well with the observed unfrozen moisture fluctuation in the top soil layer at a lodgepole pine site during 2006-2011, with a NRMSD ranging from 17% to 39%, but with consistent overestimation of 7 to 34%. Evaluations of seasonal streamflow during 2006-2011 revealed the model generally predicted well compared to observations at the basin scale, with a NRMSD of 77% and small model bias (6%), but at the sub-basin scale NRMSD were larger, ranging from 86 to 106%; though overestimation or underestimation for the cumulative seasonal discharge was within 24%. Timing of discharge was better predicted at the Marmot Creek basin outlet having a Nash-Sutcliffe efficiency (NSE) of 0.31 compared to the outlets of the sub-basins

  17. Multi-variable evaluation of hydrological model predictions for a headwater basin in the Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Fang, X.; Pomeroy, J. W.; Ellis, C. R.; MacDonald, M. K.; DeBeer, C. M.; Brown, T.

    2013-04-01

    One of the purposes of the Cold Regions Hydrological Modelling platform (CRHM) is to diagnose inadequacies in the understanding of the hydrological cycle and its simulation. A physically based hydrological model including a full suite of snow and cold regions hydrology processes as well as warm season, hillslope and groundwater hydrology was developed in CRHM for application in the Marmot Creek Research Basin (~ 9.4 km2), located in the Front Ranges of the Canadian Rocky Mountains. Parameters were selected from digital elevation model, forest, soil, and geological maps, and from the results of many cold regions hydrology studies in the region and elsewhere. Non-calibrated simulations were conducted for six hydrological years during the period 2005-2011 and were compared with detailed field observations of several hydrological cycle components. The results showed good model performance for snow accumulation and snowmelt compared to the field observations for four seasons during the period 2007-2011, with a small bias and normalised root mean square difference (NRMSD) ranging from 40 to 42% for the subalpine conifer forests and from 31 to 67% for the alpine tundra and treeline larch forest environments. Overestimation or underestimation of the peak SWE ranged from 1.6 to 29%. Simulations matched well with the observed unfrozen moisture fluctuation in the top soil layer at a lodgepole pine site during the period 2006-2011, with a NRMSD ranging from 17 to 39%, but with consistent overestimation of 7 to 34%. Evaluations of seasonal streamflow during the period 2006-2011 revealed that the model generally predicted well compared to observations at the basin scale, with a NRMSD of 60% and small model bias (1%), while at the sub-basin scale NRMSDs were larger, ranging from 72 to 76%, though overestimation or underestimation for the cumulative seasonal discharge was within 29%. Timing of discharge was better predicted at the Marmot Creek basin outlet, having a Nash

  18. Precipitation and temperature variations affecting glacierised Himalayan headwaters and water resources in the upper Indus and Sutlej basins

    NASA Astrophysics Data System (ADS)

    Collins, D. N.; Eaton, D.; Entwistle, N. S.

    2013-12-01

    Both the main stem upper Indus and Sutlej rivers feed major reservoirs for hydropower plants and supply water for irrigated agriculture in the Punjab plains. Flows in both rivers have shown significant decreases since the mid-20th century. Monsoon precipitation, which dominates flow in lower Himalayan section of the Sutlej as the upper basin on the Tibetan plateau is fairly dry, has declined by about 30% since the 1950s maximum. Air temperatures decreased from the 1960s to 1980s before recovering in the early 2000s to previous levels. Any enhanced glacier melt in the late twentieth century failed to offset declining precipitation and river flow continued to fall. In the upper Indus basin, precipitation derived in winter from the westerlies was enhanced but temperatures remained flat at stations in valleys at which measurements were undertaken. Runoff from tributary basins of the Indus, which have variable percentages of ice-cover, appears to be subdued as precipitation gently increased. Temperature was more stable than in mountain basins farther east. Valley bottoms in the Karakoram are arid, so that precipitation on glaciers reduces flow but there is little seasonal slow to melt to contribute to runoff in the ice-free areas. Changes in glacierised area seem to have limited impact on flow in these two significant rivers. Precipitation in Himalayan sub-catchments dominates flow, but has contrasting effects on runoff downstream. Temporal variations in both winter and summer precipitation along the Himalayan arc therefore have strong influences on the sustainability of water resources in the adjacent plains.

  19. Potential compensation of hydrological extremes in headwaters: case study of upper Vltava River basin, Šumava Mts., Czechia

    NASA Astrophysics Data System (ADS)

    Kocum, Jan; Janský, Bohumír.; Česák, Julius

    2010-05-01

    Increasing frequency of catastrophic flash floods and extreme droughts in recent years results in an urgent need of solving of flood protection questions and measures leading to discharge increase in dry periods. Flattening of discharge call for the use of untraditional practices as a suitable complement to classical engineering methods. These measures could be represented by gradual increase of river catchment retention capacity in headstream areas. Very favorable conditions for this research solution are concentrated to the upper part of Otava River basin (Vltava River left tributary, Šumava Mts., southwestern Czechia) representing the core zone of a number of extreme floods in Central Europe and the area with high peat land proportion. A number of automatic ultrasound and hydrostatic pressure water level gauges, climatic stations and precipitation gauges and utilization of modern equipment and methods were used in chosen experimental catchments to assess the landscape retention potential and to find out rainfall-runoff relations in this area. Successively, the detailed analysis of peat land hydrological function was carried out. The peat bogs influence on runoff conditions were assessed by thorough comparison of runoff regimes in subcatchments with different peat land proportion. The peat bog influence on hydrological process can be considered also with respect to its affecting of water quality. Therefore, hydrological monitoring was completed by ion, carbon (TOC) and oxygen isotopes balance observing within periods of high or low discharges in order to precise runoff phases separation by means of anion deficiency. Pedological survey of different soil types and textures was carried out to precise the estimation of its water capacity. Detailed analyses of extreme runoff ascending and descending phases and minimum discharges in profiles closing several subcatchments with different physical-geographic conditions show higher peak flow frequency and their shorter

  20. Characterizing the primary material sources and dominant erosional processes for post-fire debris-flow initiation in a headwater basin using multi-temporal terrestrial laser scanning data

    NASA Astrophysics Data System (ADS)

    Staley, Dennis M.; Wasklewicz, Thad A.; Kean, Jason W.

    2014-06-01

    Wildfire dramatically alters the hydrologic response of a watershed such that even modest rainstorms can produce hazardous debris flows. Relative to shallow landslides, the primary sources of material and dominant erosional processes that contribute to post-fire debris-flow initiation are poorly constrained. Improving our understanding of how and where material is eroded from a watershed during a post-fire debris-flow requires (1) precise measurements of topographic change to calculate volumetric measurements of erosion and deposition, and (2) the identification of relevant morphometrically defined process domains to spatially constrain these measurements of erosion and deposition. In this study, we combine the morphometric analysis of a steep, small (0.01 km2) headwater drainage basin with measurements of topographic change using high-resolution (2.5 cm) multi-temporal terrestrial laser scanning data made before and after a post-fire debris flow. The results of the morphometric analysis are used to define four process domains: hillslope-divergent, hillslope-convergent, transitional, and channelized incision. We determine that hillslope-divergent and hillslope-convergent process domains represent the primary sources of material over the period of analysis in the study basin. From these results we conclude that raindrop-impact induced erosion, ravel, surface wash, and rilling are the primary erosional processes contributing to post-fire debris-flow initiation in the small, steep headwater basin. Further work is needed to determine (1) how these results vary with increasing drainage basin size, (2) how these data might scale upward for use with coarser resolution measurements of topography, and (3) how these results change with evolving sediment supply conditions and vegetation recovery.

  1. Characterizing the primary material sources and dominant erosional processes for post-fire debris-flow initiation in a headwater basin using multi-temporal terrestrial laser scanning data

    USGS Publications Warehouse

    Staley, Dennis M.; Waslewicz, Thad A.; Kean, Jason W.

    2014-01-01

    Wildfire dramatically alters the hydrologic response of a watershed such that even modest rainstorms can produce hazardous debris flows. Relative to shallow landslides, the primary sources of material and dominant erosional processes that contribute to post-fire debris-flow initiation are poorly constrained. Improving our understanding of how and where material is eroded from a watershed during a post-fire debris-flow requires (1) precise measurements of topographic change to calculate volumetric measurements of erosion and deposition, and (2) the identification of relevant morphometrically defined process domains to spatially constrain these measurements of erosion and deposition. In this study, we combine the morphometric analysis of a steep, small (0.01 km2) headwater drainage basin with measurements of topographic change using high-resolution (2.5 cm) multi-temporal terrestrial laser scanning data made before and after a post-fire debris flow. The results of the morphometric analysis are used to define four process domains: hillslope-divergent, hillslope-convergent, transitional, and channelized incision. We determine that hillslope-divergent and hillslope-convergent process domains represent the primary sources of material over the period of analysis in the study basin. From these results we conclude that raindrop-impact induced erosion, ravel, surface wash, and rilling are the primary erosional processes contributing to post-fire debris-flow initiation in the small, steep headwater basin. Further work is needed to determine (1) how these results vary with increasing drainage basin size, (2) how these data might scale upward for use with coarser resolution measurements of topography, and (3) how these results change with evolving sediment supply conditions and vegetation recovery.

  2. Alternative methods to determine headwater benefits

    SciTech Connect

    Bao, Y.S.; Perlack, R.D.; Sale, M.J.

    1997-11-10

    In 1992, the Federal Energy Regulatory Commission (FERC) began using a Flow Duration Analysis (FDA) methodology to assess headwater benefits in river basins where use of the Headwater Benefits Energy Gains (HWBEG) model may not result in significant improvements in modeling accuracy. The purpose of this study is to validate the accuracy and appropriateness of the FDA method for determining energy gains in less complex basins. This report presents the results of Oak Ridge National Laboratory`s (ORNL`s) validation of the FDA method. The validation is based on a comparison of energy gains using the FDA method with energy gains calculated using the MWBEG model. Comparisons of energy gains are made on a daily and monthly basis for a complex river basin (the Alabama River Basin) and a basin that is considered relatively simple hydrologically (the Stanislaus River Basin). In addition to validating the FDA method, ORNL was asked to suggest refinements and improvements to the FDA method. Refinements and improvements to the FDA method were carried out using the James River Basin as a test case.

  3. Runoff Responses to Forest Thinning at Plot and Catchment Scales in a Headwater Catchment Draining Japanese Cypress Forest

    EPA Science Inventory

    We examined the effect of forest thinning on runoff generation at plot and catchment scales in headwater basins draining a Japanese cypress (Chamaecyparis obtusa) forest. We removed 58.3% of the stems (corresponding to 43.2% of the basal area) in the treated headwater basin (catc...

  4. Suckers in headwater tributaries, Wyoming

    USGS Publications Warehouse

    Sweet, D.E.; Compton, R.I.; Hubert, W.A.

    2009-01-01

    Bluehead sucker (Catostomus discobolus) and flannelmouth sucker (Catostomus latipinnis) populations are declining throughout these species' native ranges in the Upper Colorado River Basin. In order to conserve these populations, an understanding of population dynamics is needed. Using age estimates from pectoral fin rays, we describe age and growth of these 2 species in 3 Wyoming stream systems: Muddy Creek, the Little Sandy River, and the Big Sandy River. Within all 3 stream systems, flannelmouth suckers were longer-lived than bluehead suckers, with maximum estimated ages of 16 years in Muddy Creek, 18 years in Little Sandy Creek, and 26 years in the Big Sandy River. Bluehead suckers had maximum estimated ages of 8 years in Muddy Creek, 10 years in Little Sandy Creek, and 18 years in the Big Sandy River. These maximum estimated ages were substantially greater than in other systems where scales have been used to estimate ages. Mean lengths at estimated ages were greater for flannelmouth suckers than for bluehead suckers in all 3 streams and generally less than values published from other systems where scales were used to estimate ages. Our observations of long life spans and slow growth rates among bluehead suckers and flannelmouth suckers were probably associated with our use of fin rays to estimate ages as well as the populations being in headwater tributaries near the northern edges of these species' ranges.

  5. Evaluating the present annual water budget of a Himalayan headwater river basin using a high-resolution atmosphere-hydrology model

    NASA Astrophysics Data System (ADS)

    Li, Lu; Gochis, David J.; Sobolowski, Stefan; Mesquita, Michel d. S.

    2016-04-01

    Understanding the present water budget in Himalayan basins is a challenge due to poor in-situ coverage, incomplete or unreliable records and the limitations of coarse resolution gridded dataset. In the study, a two-way coupled implementation of the Weather Research and Forecasting model (v3.5.1) and the WRF-Hydro hydrological modeling extension package (WRF/WRF-Hydro) was employed in its offline configuration, over a 10-year simulation period for a mountainous and topographically complex Beas river basin (up to Pandoh) in North India. A triple nest is employed, in which the innermost nest domain had an atmospheric model grid spacing of 3 km and a grid spacing of 300 meters for the hydrological routing components. Two microphysical parameterization schemes are quantitatively evaluated in the study to reveal how sensitively and differently microphysical parameterization (MP) influence orographic-related precipitation, and in turn, how it impacts hydrological responses. Two sensitivity experiments of the surface-flow parameter and glacier wastage were also tested for uncertainty analysis in the study. The WRF-Hydro modeling system shows reasonable skill in capturing the spatial and temporal structure of high-resolution precipitation and the resulting stream flow hydrographs exhibit a good correspondence with observed streamflow at monthly timescales, although the model tends to generally underestimate streamflow amounts. The Thompson scheme fits better to the observations than the WSM3 schemes in the study. More importantly, WRF showed that for high altitude precipitation, the Beas River exhibits a high 'bias' in winter precipitation from both MPs, which is about double to triple that as estimated from valley-sited rain gauges, and remotely sensed precipitation estimates from both TRMM and APHRODITE. While the distribution of simulated daily discharge values agrees well with the gamma distribution from observed discharge. This correspondence suggests that the major

  6. A new species of Characidium Reinhardt (Ostariophysi: Characiformes: Crenuchidae) from headwaters of Rio Pacaás Novos, Rio Madeira basin, Rondônia, Brazil.

    PubMed

    Zanata, Angela M; Ohara, Willian M

    2015-09-25

    Characidium summus, new species, is described from rio Pacaás Novos, rio Madeira basin, Rondônia, Brazil. The new species is the unique among congeners for completely lacking an adipose fin and having a complete lateral line. Characidium summus can be further distinguished from congeners, including C. vestigipinne that also has a complete lateral line and adipose fin absent, vestigial or reduced by the absence of dark bars or spots on head, body or fins, except for a dark blotch on the rear of the opercle, a narrow midlateral dark stripe, and a dark basicaudal spot. In addition, C. summus possess a vestigial supraorbital and a remarkably small pseutotympanum. The possible mimetic relationship between the new species with Erythrinus erythrinus is discussed.

  7. Reduction of stream sediment concentration by a riparian buffer: filtering of road runoff in disturbed headwater basins of montane mainland southeast Asia.

    PubMed

    Ziegler, Alan D; Negishi, Junjiro; Sidle, Roy C; Preechapanya, Pornchai; Sutherland, Ross A; Giambelluca, Thomas W; Jaiaree, Sathaporn

    2006-01-01

    We determined the extent that a riparian buffer reduces stream suspended sediment concentrations by filtering road runoff during 18 rain events in a 2.5-ha, multi-use watershed in northern Thailand. The dominant buffer species was the perennial sedge Fimbristylis aphylla Zoll. ex Steud. (Cyperaceae). We monitored stream sediment concentration for situations where road runoff either flowed into the riparian buffer or was diverted directly into the stream (buffer and no buffer scenarios). These data were used to develop the following relationships between instantaneous stream sediment concentration (Ci) and discharge (Qi): Ci= 28.329Qi(0.851) (buffer scenario) and Ci= 22.265Qi(1.579) (no buffer scenario). Using these functions to calculate total event suspended concentrations, we determined that the buffer reduced suspended sediment concentration by 34 to 87%, for the range of events monitored. Removal of sediment from runoff generated on a 2.4-m-wide, 165-m-long unpaved road section was achieved principally via ponding, which reduced the transport capacity as flow entered the relatively flat, saturated buffer. Sediment deposition occurred primarily within the first 10 m of the buffer. Some sediment was also deposited on the fillslope leading to the buffer. Maximum road sediment concentration during the largest buffer event approached 100,000 mg L(-1). Meanwhile, the corresponding maximum stream suspended sediment concentration was <4000 mg L(-1). In contrast, maximum stream concentrations when flow bypassed the buffer during smaller events were commonly 4000 to 7000 mg L(-1). Naturally occurring buffers represent an economical means of mitigating road-related impacts in upland basins in Southeast Asia, particularly if combined with measures limiting sediment and runoff production on contributing road sections.

  8. Effects of land use and land cover on selected soil quality indicators in the headwater area of the Blue Nile basin of Ethiopia.

    PubMed

    Teferi, Ermias; Bewket, Woldeamlak; Simane, Belay

    2016-02-01

    Understanding changes in soil quality resulting from land use and land management changes is important to design sustainable land management plans or interventions. This study evaluated the influence of land use and land cover (LULC) on key soil quality indicators (SQIs) within a small watershed (Jedeb) in the Blue Nile Basin of Ethiopia. Factor analysis based on principal component analysis (PCA) was used to determine different SQIs. Surface (0-15 cm) soil samples with four replications were collected from five main LULC types in the watershed (i.e., natural woody vegetation, plantation forest, grassland, cultivated land, and barren land) and at two elevation classes (upland and midland), and 13 soil properties were measured for each replicate. A factorial (2 × 5) multivariate analysis of variance (MANOVA) showed that LULC and altitude together significantly affected organic matter (OM) levels. However, LULC alone significantly affected bulk density and altitude alone significantly affected bulk density, soil acidity, and silt content. Afforestation of barren land with eucalypt trees can significantly increase the soil OM in the midland part but not in the upland part. Soils under grassland had a significantly higher bulk density than did soils under natural woody vegetation indicating that de-vegetation and conversion to grassland could lead to soil compaction. Thus, the historical LULC change in the Jedeb watershed has resulted in the loss of soil OM and increased soil compaction. The study shows that a land use and management system can be monitored if it degrades or maintains or improves the soil using key soil quality indicators.

  9. Aquatic insect assemblages associated with subalpine stream segment types in relict glaciated headwaters

    USGS Publications Warehouse

    Kubo, Joshua S.; Torgersen, Christian E.; Bolton, Susan M.; Weekes, Anne A.; Gara, Robert I.

    2013-01-01

    1. Aquatic habitats and biotic assemblages in subalpine headwaters are sensitive to climate and human impacts. Understanding biotic responses to such perturbations and the contribution of high-elevation headwaters to riverine biodiversity requires the assessment of assemblage composition among habitat types. We compared aquatic insect assemblages among headwater stream segment types in relict glaciated subalpine basins in Mt. Rainier National Park, Washington, USA. 2. Aquatic insects were collected during summer and autumn in three headwater basins. In each basin, three different stream segment types were sampled: colluvial groundwater sources, alluvial lake inlets, and cascade-bedrock lake outlets. Ward's hierarchical cluster analysis revealed high β diversity in aquatic insect assemblages, and non-metric multidimensional scaling indicated that spatial and temporal patterns in assemblage composition differed among headwater stream segment types. Aquatic insect assemblages showed more fidelity to stream segment types than to individual basins, and the principal environmental variables associated with assemblage structure were temperature and substrate. 3. Indicator species analyses identified specific aquatic insects associated with each stream segment type. Several rare and potentially endemic aquatic insect taxa were present, including the recently described species, Lednia borealis (Baumann and Kondratieff). 4. Our results indicate that aquatic insect assemblages in relict glaciated subalpine headwaters were strongly differentiated among stream segment types. These results illustrate the contribution of headwaters to riverine biodiversity and emphasise the importance of these habitats for monitoring biotic responses to climate change. Monitoring biotic assemblages in high-elevation headwaters is needed to prevent the potential loss of unique and sensitive biota.

  10. Bifurcation characteristics and safe basin of MSMA microgripper subjected to stochastic excitation

    SciTech Connect

    Zhu, Z. W. Li, X. M.; Xu, J.

    2015-02-15

    A kind of magnetic shape memory alloy (MSMA) microgripper is proposed in this paper, and its nonlinear dynamic characteristics are studied when the stochastic perturbation is considered. Nonlinear differential items are introduced to explain the hysteretic phenomena of MSMA, and the constructive relationships among strain, stress, and magnetic field intensity are obtained by the partial least-square regression method. The nonlinear dynamic model of a MSMA microgripper subjected to in-plane stochastic excitation is developed. The stationary probability density function of the system’s response is obtained, the transition sets of the system are determined, and the conditions of stochastic bifurcation are obtained. The homoclinic and heteroclinic orbits of the system are given, and the boundary of the system’s safe basin is obtained by stochastic Melnikov integral method. The numerical and experimental results show that the system’s motion depends on its parameters, and stochastic Hopf bifurcation appears in the variation of the parameters; the area of the safe basin decreases with the increase of the stochastic excitation, and the boundary of the safe basin becomes fractal. The results of this paper are helpful for the application of MSMA microgripper in engineering fields.

  11. Are postglacial sediment yields of mountain headwaters out of pace?

    NASA Astrophysics Data System (ADS)

    Hoffmann, Thomas

    2014-05-01

    Many high mountains have been sculpted by strong glacial erosion during the Pleistocene that resulted in valley widening and overdeepening and the formation of glacial cirques, U-shaped valleys, and widespread glacial deposits. The retreat of glacial ice exposes oversteepened hillslopes that are susceptible to rockfalls, deep-seated landsliding, gully erosion, and debris flows, and can also result in valley aggradation and reworking of valley deposits through debris flow activity and fluvial processes. It has been argued that sediment fluxes caused by these processes remain elevated even several thousand years after the retreat of valley glaciers. Yet, our knowledge on the response times of postglacial mountain systems to Pleistocene glacial erosion remains insufficient. Here I represent an approach to calculate the response times of postglacial geomorphic systems to Pleistocene glacial erosion based on reservoir theory and the compilation of postglacial sediment budgets in alpine systems. The study is conducted in the Kananaskis Country in the Canadian Rocky Mountains, in which sediment budgets of 5 headwater basins have been complied. The sediment budgets show that sediment delivery from formerly glaciated headwaters is limited indicated by average postglacial sediment delivery ratios (SDR) ranging between 0 and 0.3. The low SDRs are controlled by the glacial history of the headwater and suggest that the response times of sediment flux in alpine headwater basins is in the order of 100-500 kyr. Thus postglacial adjustment of alpine sediment flux exceeds the recurrence interval of the large ice ages during the Pleistocene suggesting that mountain headwaters in the Canadian Rockies are out of pace with respect to glacially-induced changes.

  12. Nitrate removal and denitrification in headwater agricultural streams of the Pacific Northwest

    EPA Science Inventory

    Headwater streams can serve as important sites for nitrogen (N) removal in watersheds. Here we examine the influence of agricultural streams on watershed N export in the Willamette River Basin of western Oregon, USA, a region with mixed agricultural, urban and forestry land uses...

  13. Burial affects the biogeochemistry of headwater streams in a midwestern US metropolitan area

    EPA Science Inventory

    Nitrogen (N) retention in stream networks is an important ecosystem service that may be affected by the widespread burial of headwater streams in urban basins. Urban stream burial has only recently been recognized by ecologists and little research has addressed the extent to whi...

  14. Burial affects the biogeochemistry of headwater streams in a midwestern US metropolitan area - slides

    EPA Science Inventory

    Nitrogen (N) retention in stream networks is an important ecosystem service that may be affected by the widespread burial of headwater streams in urban basins. Urban stream burial has only recently been recognized by ecologists as a regional environmental impact and little resea...

  15. Comparison of peak discharges among sites with and without valley fills for the July 8-9, 2001 flood in the headwaters of Clear Fork, Coal River basin, mountaintop coal-mining region, southern West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Brogan, Freddie D.

    2003-01-01

    The effects of mountaintop-removal mining practices on the peak discharges of streams were investigated in six small drainage basins within a 7-square-mile area in southern West Virginia. Two of the small basins had reclaimed valley fills, one basin had reclaimed and unreclaimed valley fills, and three basins did not have valley fills. Indirect measurements of peak discharge for the flood of July 8-9, 2001, were made at six sites on streams draining the small basins. The sites without valley fills had peak discharges with 10- to 25-year recurrence intervals, indicating that rainfall intensities and totals varied among the study basins. The flood-recurrence intervals for the three basins with valley fills were determined as though the peak discharges were those from rural streams without the influence of valley fills, and ranged from less than 2 years to more than 100 years.

  16. A New User-Friendly Model to Reduce Cost for Headwater Benefits Assessment

    SciTech Connect

    Bao, Y.S.; Cover, C.K.; Perlack, R.D.; Sale, M.J.; Sarma, V.

    1999-07-07

    Headwater benefits at a downstream hydropower project are energy gains that are derived from the installation of upstream reservoirs. The Federal Energy Regulatory Commission is required by law to assess charges of such energy gains to downstream owners of non-federal hydropower projects. The high costs of determining headwater benefits prohibit the use of a complicated model in basins where the magnitude of the benefits is expected to be small. This paper presents a new user-friendly computer model, EFDAM (Enhanced Flow Duration Analysis Method), that not only improves the accuracy of the standard flow duration method but also reduces costs for determining headwater benefits. The EFDAM model includes a MS Windows-based interface module to provide tools for automating input data file preparation, linking and executing of a generic program, editing/viewing of input/output files, and application guidance. The EDFAM was applied to various river basins. An example was given to illustrate the main features of EFDAM application for creating input files and assessing headwater benefits at the Tulloch Hydropower Plant on the Stanislaus River Basin, California.

  17. BASINS

    EPA Pesticide Factsheets

    Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) is a multipurpose environmental analysis system designed to help regional, state, and local agencies perform watershed- and water quality-based studies.

  18. Characterizing hydrologic permanence in headwater streams

    EPA Science Inventory

    The presentation will be an overview of research to inform jurisdictional determinations for the Clean Water Act, in particular research that hydrographic comparisons of the extent and hydrologic permanence of headwater streams, indicator development, and an evaluation of a rapid...

  19. Headwater Streams in Porous Landscapes - What's the contributing area?

    NASA Astrophysics Data System (ADS)

    Jackson, C. R.; Bitew, M. M.; Du, E.; Griffiths, N.; Hopp, L.; Klaus, J.; McDonnell, J.; Vache, K. B.

    2015-12-01

    Building on a long legacy of hydrogeological investigations at the Savannah River Site in the Sandhills of the Upper Coastal Plain in South Carolina, we began in 2005 a headwater-scale investigation of hillslope flow pathways, streamflow sources, and water quality responses to intensive woody biomass production. The landscape is characterized by blackwater streams flowing slowly through wide flat stream valleys, deep unconsolidated layers of sands and clays, a regional clay layer beneath Fourmile Creek that defines the lower boundary of the surficial aquifer, rolling topography with steeper slopes on the valley margins and gentle slopes elsewhere, and a sandy clay loam argillic layer within 0.2 to 1.5m from the surface. Most water leaves headwater basins by groundwater flow, appearing as streamflow far downstream. Only at scales larger than 50 km2 does average streamflow match expectations from water balances. This raises the question, what constitutes the contributing area for headwater streams in porous landscapes? Perching and interflow generation over the argillic horizon is common, but leakage through clay is rapid relative to interflow travel times, so interflow serves to shift the point of percolation downslope from the point of infiltration. Only interflow from the valley-adjacent slopes can contribute to stormflow responses. Our interflow interception trenches and maximum rise piezometer networks reveal high heterogeneity in subsurface flow paths at multiple spatial scales. Streamwater has isotopic and chemical characteristics similar to deep groundwater, but we cannot easily determine the source area for groundwater reaching the first order streams. Our observations suggest that one's view of hillslope and catchment flow processes depends on the scale, number, and frequency of observations of state variables and outputs. In some cases, less frequent or less numerous observations of fewer tracers would have yielded different inferences. The data also

  20. Suspended sediment fluxes in an Indonesian river draining a rainforested basin subject to land cover change

    NASA Astrophysics Data System (ADS)

    Buschman, F.; Hoitink, A.; de Jong, S.; Hoekstra, P.

    2011-12-01

    Forest clearing in the tropics for reasons of timber production, open pit mining and the establishment of oil palm plantations generally results in excessively high sediment loads. The increasing sediment fluxes pose a threat to coastal marine ecosystems such as coral reefs. This study presents observations of suspended sediment fluxes in the Berau river (Indonesia), which debouches into a coastal ocean that can be considered the preeminent center of coral diversity. The Berau is an example of a small river draining a mountainous, relatively pristine basin that receives abundant rainfall. Flow velocity was measured over a large part of the river width at a station under the influence of tides, using a Horizontal Acoustic Doppler Current Profiler (HADCP). Surrogate measurements of suspended sediment concentration were taken with an Optical Backscatter Sensor (OBS). Tidally averaged suspended sediment concentration increases with river discharge, implying that the tidally averaged suspended sediment flux increases non-linearly with river discharge. Averaged over the 6.5 weeks covered by the benchmark survey, the tidally averaged suspended sediment flux was estimated at 2 Mt/y. Considering the wet conditions during the observation period, this figure may be considered as an upper limit of the yearly averaged flux. This flux is significantly smaller than what could have been expected from the characteristics of the catchment. Furthermore, the consequences of ongoing clearing of rainforest were explored using a plot scale erosion model. When rainforest, which still covered 50 - 60 % of the basin in 2007, is converted to production land, soil loss is expected to increase with a factor between 10 and 100. If this soil loss is transported seaward as suspended sediment, the increase in suspended sediment flux in the Berau river would impose a severe sediment stress on the global hotspot of coral reef diversity. The impact of land cover changes will largely depend on the

  1. Suspended sediment fluxes in an Indonesian river draining a rainforested basin subject to land cover change

    NASA Astrophysics Data System (ADS)

    Buschman, F. A.; Hoitink, A. J. F.; de Jong, S. M.; Hoekstra, P.

    2011-07-01

    Forest clearing for reasons of timber production, open pit mining and the establishment of oil palm plantations generally results in excessively high sediment loads in the tropics. The increasing sediment fluxes pose a threat to coastal marine ecosystems such as coral reefs. This study presents observations of suspended sediment fluxes in the Berau river (Indonesia), which debouches into a coastal ocean that can be considered the preeminent center of coral diversity. The Berau is an example of a small river draining a mountainous, relatively pristine basin that receives abundant rainfall. Flow velocity was measured over a large part of the river width at a station under the influence of tides, using a Horizontal Acoustic Doppler Current Profiler (HADCP). Surrogate measurements of suspended sediment concentration were taken with an Optical Backscatter Sensor (OBS). Tidally averaged suspended sediment concentration increases with river discharge, implying that the tidally averaged suspended sediment flux increases non-linearly with river discharge. Averaged over the 6.5 weeks observations covered by the benchmark survey, the tidally averaged suspended sediment flux was estimated at 2 Mt y-1. Considering the wet conditions during the observation period, this figure may be considered as an upper limit of the yearly averaged flux. This flux is significantly smaller than what could have been expected from the characteristics of the catchment. The consequences of ongoing clearing of rainforest were explored using a plot scale erosion model. When rainforest, which still covered 50-60 % of the basin in 2007, is converted to production land, soil loss is expected to increase with a factor between 10 and 100. If this soil loss is transported seaward as suspended sediment, the increase in suspended sediment flux in the Berau river would impose a severe sediment stress on the global hotspot of coral reef diversity. The impact of land cover changes will largely depend on the

  2. ARE SALAMANDERS USEFUL INDICATORS OF HYDROLOGIC PERMANENCE IN HEADWATER STREAMS?

    EPA Science Inventory

    Regulatory agencies need appropriate indicators of stream permanence to aid in jurisdictional determinations for headwater streams. We evaluated salamanders as permanence indicators because they are often abundant in fishless headwaters. Salamander and habitat data were collect...

  3. Herbicide mitigation in microcosms simulating stormwater basins subject to polluted water inputs.

    PubMed

    Bois, P; Huguenot, D; Jézéquel, K; Lollier, M; Cornu, J Y; Lebeau, T

    2013-03-01

    Non-point source pollution as a result of wine-growing activity is of high concern. Stormwater basins (SWB) found downstream of vineyard watersheds could show a potential for the mitigation of runoff water containing herbicides. In this study, mitigation of vinery-used herbicides was studied in microcosms with a very similar functioning to that recorded in SWB. Mitigation efficiency of glyphosate, diuron and 3,4-dichloroaniline (3,4-DCA) was investigated by taking into account hydraulic flow rate, mitigation duration, bioaugmentation and plant addition. Mitigation efficiency measured in water ranged from 63.0% for diuron to 84.2% for 3,4-DCA and to 99.8% for glyphosate. Water-storage duration in the SWB and time between water supplies were shown to be the most influential factors on the mitigation efficiency. Six hours water-storage duration allowed an efficient sorption of herbicides and their degradation by indigenous microorganisms in 5 weeks. Neither bioaugmentation nor plant addition had a significant effect on herbicide mitigation. Our results show that this type of SWB are potentially relevant for the mitigation of these herbicides stemming from wine-growing activity, providing a long enough hydraulic retention time.

  4. ASSESSING HEADWATER STREAMS: LINKING LANDSCAPES TO STREAM NETWORKS

    EPA Science Inventory

    Headwater streams represent a significant land-water boundary and drain 70-80% of the landscape. Headwater streams are vital components to drainage systems and are directly linked to our downstream rivers and lakes. However, alteration and loss of headwater streams have occurre...

  5. Hydrochemical water evolution in the Aral Sea Basin. Part II: Confined groundwater of the Amu Darya Delta - Evolution from the headwaters to the delta and SiO2 geothermometry

    NASA Astrophysics Data System (ADS)

    Schettler, Georg; Oberhänsli, Hedi; Stulina, Galina; Djumanov, Jamoljon H.

    2013-07-01

    We studied 40 artesian wells (AWs) in the Amu Darya Delta. These wells include high-salinity (∼52 g/l) and saline (5-24 g/l) waters but are mostly low-salinity waters (1.3-2.9 g/l). The low-salinity AWs cluster into three types, reflecting the variable mixing of different end member solutes: (residual) brines and solutes deriving from silicate alteration, dissolution of limestone and dissolution of gypsum. The solutes are all undersaturated in calcite and gypsum, contain a substantial cation excess against dissolved inorganic carbon and are characterised by low Ca/SO4 ratios. On the basis of the hydrochemical mass budgets of model cases, we demonstrate that Na-rich Cl-brines (45-48%) and a Na2SO4-brine (30-47%) are the dominant solute components. The solutes derived from aluminium silicate alteration are minor components (7.3-19.4%). Even less important are solutes from limestone or gypsum dissolution (0.05-3.7%). These waters are unlikely to have originated from sediments hosting gypsum. The low-salinity AWs must have acquired their dominant hydrochemical signatures under non-equilibrium conditions between their remote (unknown) seepage areas and their discharge locations. This acquisition may have begun during the early hydrochemical groundwater evolution when meteoric or surface water passed the critical zone under an arid climate regime. Warmer saline AWs (∼40 °C) hosted in deeper Cretaceous formations contain a high portion of NaCl-rich brine (85%) and some are saturated in gypsum. These waters were derived from fluids rising along faults from pre-Cretaceous strata. The high-salinity and relatively cold AWs discharge close to the retreating Aral Sea south of its western basin. These AWs are suboxic, and Si concentrations are very low. The AW hydrochemical signatures reflect the dissolution of halite and gypsum. We observed positive correlations between temperature, Br, B and Si. The temperature correlation with bromide likely documents the transformation

  6. INDICATORS OF HYDROLOGIC PERMANENCE IN HEADWATER STREAMS

    EPA Science Inventory

    Headwater intermittent streams lie at the aquatic-terrestrial interface and represent much of our nation's stream miles. Recent court cases concerning the definition of jurisdictional waters under the Clean Water Act have illuminated a need to better understand the characteristi...

  7. Ecosystem Services Derived from Headwater Catchments

    EPA Science Inventory

    We used data from the USEPA’s wadeable streams assessment (WSA), US Forest Service’s forest inventory and analysis (FIA), and select USFS experimental forests (EF) to investigate potential ecosystems services derived from headwater catchments. C, N, and P inputs to these catchmen...

  8. Contribution of a Headwater Stream to the Global Carbon Budget

    NASA Astrophysics Data System (ADS)

    Argerich, A.; Johnson, S. L.; Haggerty, R.; Dosch, N.; Corson-Rikert, H.; Ashkenas, L.; Pennington, R.; Wondzell, S. M.

    2014-12-01

    The carbon cycle has been subject of numerous studies in recent years, primarily due to the role of CO2 and CH4 in global warming. Understanding the components and processes contributing to the global carbon cycle across a landscape is essential to understand climate change drivers and predicting future climate. Although the role of streams and rivers in transporting and processing nutrients from the land to the ocean has been widely recognized, most climate models still consider riverine systems as mere conduits without processing capacity. Evasion of carbon dioxide from inland waters has only been recently acknowledged to be an important source of carbon to the atmosphere and still, these estimations don't take into account evasion from headwater streams due to a lack of data. Here we present a 10-year C budget for a small headwater stream draining a 96-ha watershed in western Oregon, USA. This stream exported ~5000 g C per m2 of stream area, approximately 9% of the ecosystem production of the catchment (NEP). Export is dominated by evasion of CO2 to the atmosphere (~2200 g C per m2/y) and by downstream transport of dissolved inorganic carbon (DIC, ~1300 g per m2/y). Although highest in-stream pCO2 and DIC concentrations happen during summer low-flows, most stream export happens during winter high flows indicating at least a seasonal lag between CO2 production (i.e., respiration) and carbon export.

  9. Rapid hydrologic shifts and prolonged droughts in Rocky Mountain headwaters during the Holocene

    NASA Astrophysics Data System (ADS)

    Shuman, Bryan; Pribyl, Paul; Minckley, Thomas A.; Shinker, Jacqueline J.

    2010-03-01

    Rapid hydroclimatic shifts repeatedly generated centuries to millennia of extensive aridity across the headwaters of three of North America's largest river systems during the Holocene. Evidence of past lake-level changes at the headwaters of the Snake-Columbia, Missouri-Mississippi, and Green-Colorado Rivers in the Rocky Mountains shows that aridity as extensive and likely as severe as the CE 1930s Dust Bowl developed within centuries or less at ca. 9 ka (thousand years before CE 1950), and persisted across large areas of the watersheds until ca. 3 ka. Regional water levels also shifted abruptly at >11.3 and 1.8-1.2 ka. The record of low water levels during the mid-Holocene on the Continental Divide links similar evidence from the Great Basin and the Midwestern U.S., and shows that extensive aridity was the Holocene norm even though few GCMs have simulated such a pattern.

  10. Hydroecological monitoring in the headwaters of the Volga River

    NASA Astrophysics Data System (ADS)

    Kuzovlev, Viacheslav V.; Zhenikov, Yuri N.; Zhenikov, Kyrill Y.; Shaporenko, Sergey I.; Haun, Stefan; Füreder, Leopold; Schletterer, Martin

    2016-04-01

    Europe's largest river, the Volga (3551 km), has experienced multiple stressors from human activities (i.e. the Volga Basin comprises about 40 % of the Russian population, 45 % of the country's industry and more than 50 % of its agriculture). During the research expedition "Upper Volga 2005" an assessment of hydrological, limnochemical and biological parameters was carried out by scientists from the Russian Federation and from Austria. The extensive sampling in 2005 showed that the free-flowing section of the Volga River, located upstream of Tver, represents conditions which are either reference or least disturbed - thus it can be considered as a refugial system for freshwater biota of the European lowlands. Subsequently three stretches in the headwaters of the Volga River (Rzhev, Staritsa, Tver) were selected for the monitoring programme "REFCOND_VOLGA", which is in operation since 2006. These locations correspond also with the sampling sites of ROSHYDROMET, i.e. at Tver physic-chemical samples are taken monthly and at Rzhev samples are taken in the main hydrological periods. The laboratory ship "ROSHYDROMET 11" conducted monthly cruises between Tver and Kalyazin (Ivankovskoye and Uglichskoye reservoirs on Volga) in the headwaters during the navigation period (May - October). This also includes measurements with ADCP, which further allow the analyses of the spatial distribution of the suspended solids within cross sections. In addition sediment fluxes were derived by using the acoustic backscatter signal strength from the acoustic current Doppler profiler (ADCP). We exemplify at the monitoring sites the spatial distribution of different sediments, i.e. choriotope types, according the longitudinal profile of the river. We show that it is highly influenced by morphodynamics in the different river sections and this corresponds with the zoobenthos fauna accordingly. This interdisciplinary approach, including sediment conditions, limnochemistry, hydrology and

  11. Work Element B: 157. Sampling in Fish-Bearing Reaches [Variation in Productivity in Headwater Reaches of the Wenatchee Subbasin], Final Report for PNW Research Station.

    SciTech Connect

    Polivka, Karl; Bennett, Rita L.

    2009-03-31

    within a major sub-basin of the Columbia River and associations of density with ecoregion and individuals drainages within the sub-basin. We further examined habitat metrics that show positive associations with fish abundance to see if these relationships varied at larger spatial scales. We examined the extent to which headwater fish density and temporal variation in density were correlated between the headwaters and the main tributaries of the sub-basin, and the influence of ecoregion influence on density differences, particularly at wider temporal scales. Finally, we examined demographic parameters such as growth and emigration to determine whether density-dependence differs among ecoregions or whether responses were more strongly influenced by the demography of the local fish population.

  12. Public Health Perspectives of Channelized and Unchannelized Headwater Streams in Central Ohio: A Case Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Headwater streams constitute the majority of watersheds in the United States and many headwater streams in the midwest have been channelized for agricultural drainage. Public health implications of water chemistry and aquatic macroinvertebrates within channelized and unchannelized headwater streams ...

  13. Overview of the Proposed Mississippi Headwaters - Red River Hydrologic Observatory

    NASA Astrophysics Data System (ADS)

    Schwartz, F. W.; Gerla, P. J.; Kucera, P. A.

    2004-12-01

    A consortium of universities, led by The Ohio State University and the University of North Dakota, in collaboration with The Nature Conservancy - Minnesota and the Dakotas Chapter, are proposing to develop the Mississippi Headwaters - Red River (MHRR) Hydrologic Observatory (HO). The region encompassed by the observatory includes the Red River watershed, the Upper Crow Wing River, the headwaters of the Mississippi River above Leech Lake, the closed Devils Lake basin and the central portion of the Prairie Pothole Region (PPR). The MHRR HO covers about 101,000 km2 and straddles the continental divide. The large size will permit the study of unique science problems and will provide a large contiguous region suitable for coupled large-scale climatic/hydrologic/ecological investigations. Although not part of this proposal, we are also organizing a consortium of primarily Canadian universities interested in carrying out complementary studies on the large Assiniboine basin in Manitoba and Saskatchewan with funding from Canadian sources. The combined study areas will facilitate climate/hydrologic/ecological studies on a broad scale, together with much more focused local scale studies. The research plan focuses on (i) climate variability and future climate change, (ii) wetland dynamics, restoration, and policy considerations associated with global climate change, (iii) carbon, nutrient, and contaminant cycling in complex systems, (iv) assessment and modeling of large, coupled climate/water systems, and (v) new and emerging technologies for near real-time monitoring and assessment. The science themes focus explicitly on exploring the interfaces among traditional science disciplines (hydrology, ecology, climatology) and implicitly on the atmosphere/land surface/subsurface interfaces that are part of the hydrologic cycle. The location of the MHRR HO was purposely selected as one of the most promising areas to pursue these science and technology themes. The region is

  14. Habitat selection by juvenile Swainson’s thrushes (Catharus ustulatus) in headwater riparian areas, northwestern Oregon, USA

    USGS Publications Warehouse

    Jenkins, Stephanie R.; Betts, Matthew G.; Huso, Manuela M.; Hagar, Joan C.

    2013-01-01

    Lower order, non-fish-bearing streams, often termed “headwater streams”, have received minimal research effort and protection priority, especially in mesic forests where distinction between riparian and upland vegetation can be subtle. Though it is generally thought that breeding bird abundance is higher in riparian zones, little is known about species distributions when birds are in their juvenile stage – a critical period in terms of population viability. Using radio telemetry, we examined factors affecting habitat selection by juvenile Swainson’s thrushes during the post-breeding period in headwater basins in the Coast Range of Oregon, USA. We tested models containing variables expected to influence the amount of food and cover (i.e., deciduous cover, coarse wood volume, and proximity to stream) as well as models containing variables that are frequently measured and manipulated in forest management (i.e., deciduous and coniferous trees separated into size classes). Juvenile Swainson’s thrushes were more likely to select locations with at least 25% cover of deciduous, mid-story vegetation and more than 2.0 m3/ha of coarse wood within 40 m of headwater streams. We conclude that despite their small and intermittent nature, headwater streams and adjacent riparian areas are selected over upland areas by Swainson’s thrush during the postfledging period in the Oregon Coast Range.

  15. HEADWATER INTERMITTENT STREAMS STUDY: COLLABORATION ACROSS THE NATION

    EPA Science Inventory

    Headwater streams are the most abundant and widespread of our nation's surface waters, yet little guidance is available specific to these resources. Headwater streams lie at the terrestrial-aquatic interface, both spatially because of their narrow channels and landscape position ...

  16. Geology, Streamflow, and Water Chemistry of the Talufofo Stream Basin, Saipan, Northern Mariana Islands

    USGS Publications Warehouse

    Izuka, Scot K.; Ewart, Charles J.

    1995-01-01

    ions in water samples from Talufofo Stream are characteristic of water draining a heavily vegetated basin near the ocean. The streamflow and water-chemistry data indicate that discharge from springs is in hydraulic connection with the limestone aquifer near the headwaters of the basin. The base flow therefore is subject to stresses placed on the nearby limestone ground-water system. Pumping from wells in the limestones at the headwaters of Talufofo Stream Basin may decrease spring flow in Talufofo Stream.

  17. The impact of droughts and water management on various hydrological systems in the headwaters of the Tagus River (central Spain)

    NASA Astrophysics Data System (ADS)

    Lorenzo-Lacruz, J.; Vicente-Serrano, S. M.; López-Moreno, J. I.; Beguería, S.; García-Ruiz, J. M.; Cuadrat, J. M.

    2010-05-01

    SummaryThe influence of climate variation on the availability of water resources was analyzed in the headwaters of the Tagus River basin using two drought indices, the standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI). This basin is highly regulated and strategic, and contains two hyperannual reservoirs that are the origin of the water supply system for Mediterranean areas of southeast Spain. The indices confirmed that drought conditions have prevailed in the headwaters of the Tagus River since the 1970s. The responses in river discharge and reservoir storage were slightly higher when based on the SPEI rather than the SPI, which indicates that although precipitation had a major role in explaining temporal variability in the analyzed parameters, the influence of temperature was not negligible. Moreover, the greatest response in hydrological variables was evident over longer timescales of the climatic drought indices. Although the effect of climate variability on water resources was substantial during the analyzed period, we also showed a major change in hydrological-climatic relationships in regulated systems including reservoir storage and outflow. These were closely related to changes in external demand following commencement of the water transfer system to the Júcar and Segura basins after the 1980s. The marked reduction in water availability in the basin, which is related to more frequent droughts, contrasts with the amount of water transferred, which shows a clear upward trend associated with increasing water demand in the Mediterranean basin.

  18. Model‐based analysis of the influence of catchment properties on hydrologic partitioning across five mountain headwater subcatchments

    PubMed Central

    Wagener, Thorsten; McGlynn, Brian

    2015-01-01

    Abstract Ungauged headwater basins are an abundant part of the river network, but dominant influences on headwater hydrologic response remain difficult to predict. To address this gap, we investigated the ability of a physically based watershed model (the Distributed Hydrology‐Soil‐Vegetation Model) to represent controls on metrics of hydrologic partitioning across five adjacent headwater subcatchments. The five study subcatchments, located in Tenderfoot Creek Experimental Forest in central Montana, have similar climate but variable topography and vegetation distribution. This facilitated a comparative hydrology approach to interpret how parameters that influence partitioning, detected via global sensitivity analysis, differ across catchments. Model parameters were constrained a priori using existing regional information and expert knowledge. Influential parameters were compared to perceptions of catchment functioning and its variability across subcatchments. Despite between‐catchment differences in topography and vegetation, hydrologic partitioning across all metrics and all subcatchments was sensitive to a similar subset of snow, vegetation, and soil parameters. Results also highlighted one subcatchment with low certainty in parameter sensitivity, indicating that the model poorly represented some complexities in this subcatchment likely because an important process is missing or poorly characterized in the mechanistic model. For use in other basins, this method can assess parameter sensitivities as a function of the specific ungauged system to which it is applied. Overall, this approach can be employed to identify dominant modeled controls on catchment response and their agreement with system understanding. PMID:27642197

  19. Preliminary report on geophysics of the Verde River headwaters region, Arizona

    USGS Publications Warehouse

    Langenheim, V.E.; Duval, J.S.; Wirt, Laurie; DeWitt, Ed

    2000-01-01

    This report summarizes the acquisition, data processing, and preliminary interpretation of a high-resolution aeromagnetic and radiometric survey near the confluence of the Big and Little Chino basins in the headwaters of the Verde River, Arizona. The goal of the aeromagnetic study is to improve understanding of the geologic framework as it affects groundwater flow, particularly in relation to the occurrence of springs in the upper Verde River headwaters region. Radiometric data were also collected to map surficial rocks and soils, thus aiding geologic mapping of the basin fill. Additional gravity data were collected to enhance existing coverage. Both aeromagnetic and gravity data indicate a large gradient along the Big Chino fault, a fault with Quaternary movement. Filtered aeromagnetic data show other possible faults within the basin fill and areas where volcanic rocks are shallowly buried. Gravity lows associated with Big Chino and Williamson Valleys indicate potentially significant accumulations of low-density basin fill. The absence of a gravity low associated with Little Chino Valley indicates that high-density rocks are shallow. The radiometric maps show higher radioactivity associated with the Tertiary latites and with the sediments derived from them. The surficial materials on the eastern side of the Big Chino Valley are significantly lower in radioactivity and reflect the materials derived from the limestone and basalt east of the valley. The dividing line between the low radioactivity materials to the east and the higher radioactiviy materials to the west coincides approximately with the major drainage system of the valley, locally known as Big Chino Wash. This feature is remarkably straight and is approximately parallel to the Big Chino Fault. The uranium map shows large areas with concentrations greater than 5 ppm eU, and we expect that these areas will have a significantly higher risk potential for indoor radon.

  20. The Carbon Cycle at the Nile Headwaters

    NASA Astrophysics Data System (ADS)

    Jones, Michael; Saunders, Matthew

    2014-05-01

    The carbon cycle at the Nile headwaters M B Jones, School of Natural Sciences, Trinity College, University of Dublin, Dublin 2, Ireland M Saunders, Environmental and Biochemical Sciences Group, The James Hutton Institute, Aberdeen, Scotland River systems play an integral role in the global carbon cycle by connecting the terrestrial biosphere, the atmosphere and the oceans. Extensive wetland systems, such as those found in the Amazon region, have been shown to export significant amounts of carbon to river waters as dissolved carbon dioxide (CO2) that can be transported and emitted hundreds of km downstream. The assessment of both regional and global carbon budgets could therefore be improved by quantifying these lateral carbon fluxes, especially from highly productive temporarily or permanently flooded areas where substantial CO2 evasion from inland waters can occur. The Nile is the longest river in the world and the headwaters are located in the extensive Papyrus dominated wetlands in central Africa that are associated with Lake Victoria. From its source the White Nile flows northwards through wetlands in Uganda and Sudan before it joins the Blue Nile. Papyrus wetlands have been shown to be some of the most productive global ecosystems, with recorded rates of aerial net primary productivity of up to 3.09 kg C m-2 yr-1. In addition, where anaerobic conditions occur they also accumulate large amounts of carbon in the form of peat, and under these circumstances they represent a significant carbon sink. However, as water moves through these wetlands and is exchanged with surrounding rivers and lakes significant quantities of dissolved organic and inorganic carbon as well as suspended particulate organic matter are exported, which are either released further downstream by degassing, decomposition or deposition. Information on such losses from these wetland ecosystems is extremely sparse but in order to better constrain ecosystem scale carbon dynamics more accurate

  1. Investigation of Biogeochemical Functional Proxies in Headwater Streams Across a Range of Channel and Catchment Alterations

    NASA Astrophysics Data System (ADS)

    Berkowitz, Jacob F.; Summers, Elizabeth A.; Noble, Chris V.; White, John R.; DeLaune, Ronald D.

    2014-03-01

    Historically, headwater streams received limited protection and were subjected to extensive alteration from logging, farming, mining, and development activities. Despite these alterations, headwater streams provide essential ecological functions. This study examines proxy measures of biogeochemical function across a range of catchment alterations by tracking nutrient cycling (i.e., inputs, processing, and stream loading) with leaf litter fall, leaf litter decomposition, and water quality parameters. Nutrient input and processing remained highest in second growth forests (the least altered areas within the region), while recently altered locations transported higher loads of nutrients, sediments, and conductivity. Biogeochemical functional proxies of C and N input and processing significantly, positively correlated with rapid assessment results (Pearson coefficient = 0.67-0.81; P = 0.002-0.016). Additionally, stream loading equations demonstrate that N and P transport, sediment, and specific conductivity negatively correlated with rapid assessment scores (Pearson coefficient = 0.56-0.81; P = 0.002-0.048). The observed increase in stream loading with lower rapid assessment scores indicates that catchment alterations impact stream chemistry and that rapid assessments provide useful proxy measures of function in headwater ecosystems. Significant differences in nutrient processing, stream loading, water quality, and rapid assessment results were also observed between recently altered (e.g., mined) headwater streams and older forested catchments (Mann-Whitney U = 24; P = 0.01-0.024). Findings demonstrate that biogeochemical function is reduced in altered catchments, and rapid assessment scores respond to a combination of alteration type and recovery time. An analysis examining time and economic requirements of proxy measurements highlights the benefits of rapid assessment methods in evaluating biogeochemical functions.

  2. Trends in annual and extreme flows in the Lena River basin, Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Tananaev, N. I.; Makarieva, O. M.; Lebedeva, L. S.

    2016-10-01

    A long-term daily streamflow data set, covering the period from 1925 to 2013, was compiled for the Lena River basin, with an average record length of 49 years. Time series of mean annual daily flow (MADF) and extreme (maximum, Qmax, and minimum, Qmin) daily flows were subject to trend detection and change point detection analysis. Significant changes result mostly from rapid "breakpoint" homogeneity disruptions. Thirty one time series showed trends in MADF, 10, in Qmax, and 32 of the 55 records with nonzero Qmin, significant at p ≤ 0.05. Upward trends prevail in both mean annual and extreme flows, with average magnitudes of 47% (MADF), 56% (Qmax), and 68% (Qmin). Two to three stations in each subset showed downward trends (averaging -20%, -39%, and -38%, respectively). Abrupt changes are observed in the 1990s and early 2000s mostly in the headwaters of the basin, underlain by discontinuous permafrost.

  3. Physical indicators of hydrologic permanence in forested headwater streams

    EPA Science Inventory

    Recent court cases have brought headwater streams and their hydrologic permanence into the forefront for regulatory agencies, so rapid field-based indicators of hydrologic permanence in streams are critically needed. Our study objectives were to 1) identify environmental charact...

  4. SCIENCE TO INFORM POLICY ON PROTECTION OF HEADWATER STREAMS

    EPA Science Inventory

    Recent court cases concerning the definition of jurisdictional waters under the Clean Water Act have illuminated a need to better understand characteristics and functions of headwater streams (and associated riparian and wetland habitats). Research is needed to better quantify 1...

  5. BIOLOGICAL INTEGRITY IN MID-ATLANTIC COASTAL PLAINS HEADWATER STREAMS

    EPA Science Inventory

    The objective of this study was to assess the applicability of landscape metrics, in conjunction with stream water quality to estimate the biological integrity of headwater streams in the Mid-Atlantic Coastal Plains using multivariate techniques.

  6. Landscape Pattern, Network Structure, and the Distribution of Coastal Cutthroat Trout in Headwater Streams

    NASA Astrophysics Data System (ADS)

    Torgersen, C. E.; Gresswell, R. E.; Bateman, D. S.; Hockman-Wert, D. P.

    2005-05-01

    Headwater streams are dynamic environments in which landscape characteristics exert strong influences on the distribution of stream fishes. Although geology, topographic factors, and land use have been shown to affect trout population density at a site-specific level, few studies have investigated landscape features associated with the spatial extent and scale of variation of trout distribution in an entire watershed. To evaluate landscape influences on the distribution and abundance of coastal cutthroat trout (Oncorhynchus clarki clarki), we conducted spatially continuous surveys of stream habitat and trout abundance in forty randomly selected watersheds (500-1000 ha) in the Cascades, Coast Range, and Klamath Mountains ecoregions of western Oregon. Our investigation of coastal cutthroat trout populations across a broad range of headwater environments revealed that landscape features, including topography, geology, network structure, annual precipitation, and stand replacement disturbance, were associated with the spatial extent and scale of variation of trout distribution within watersheds. Understanding effects of basin-scale factors on trout distribution and abundance is critical in forested regions such as the Pacific Northwest where resource managers must consider potential impacts of logging on aquatic ecosystems.

  7. Feeding and reproductive patterns of Astyanax intermedius in a headwater stream of Atlantic Rainforest.

    PubMed

    Souza, Ursulla P; Ferreira, Fabio C; Carmo, Michele A F; Braga, Francisco M S

    2015-01-01

    In this paper, we determined diet composition, reproductive periodicity and fecundity of Astyanax intermedius in a headwater stream of a State Park of an Atlantic rainforest. We also evaluated the influence of rainfall, water temperature and fish size on niche width and niche overlap. Sampling was conducted monthly throughout one year in the Ribeirão Grande stream, southeastern Brazil. Diet consisted of 31 food items with equal contribution of allochthonous and autochthonous items. Females were larger than males, and the mean sizes at first maturation were 4.44 cm and 3.92 cm, respectively. Based on 212 pairs of mature ovaries, the number of oocytes per female ranged from 538 to 6,727 (mean = 2,688.7). Niche width and niche overlap were not related to rainfall nor water temperature and only niche width increased with fish size, suggesting that as fish grow, more items are included in diet. Our results suggested that A. intermedius fit as a typical opportunistic strategist which may explain the prevalence of this species in several isolated headwater basins of vegetated Atlantic forested streams where food resources are abundant and distributed throughout the year.

  8. Recovery of sediment characteristics in moraine, headwater streams of northern Minnesota after forest harvest

    USGS Publications Warehouse

    Vondracek, Bruce C.; Merten, Eric C.; Hemstad, Nathaniel A.; Kolka, Randall K.; Newman, Raymond M.; Verry, Elon S.

    2010-01-01

    We investigated the recovery of sediment characteristics in four moraine, headwater streams in north-central Minnesota after forest harvest. We examined changes in fine sediment levels from 1997 (preharvest) to 2007 (10 years postharvest) at study plots with upland clear felling and riparian thinning, using canopy cover, proportion of unstable banks, surficial fine substrates, residual pool depth, and streambed depth of refusal as response variables. Basin-scale year effects were significant (p < 0.001) for all responses when evaluated by repeated-measures ANOVAs. Throughout the study area, unstable banks increased for several years postharvest, coinciding with an increase in windthrow and fine sediment. Increased unstable banks may have been caused by forest harvest equipment, increased windthrow and exposure of rootwads, or increased discharge and bank scour. Fine sediment in the channels did not recover by summer 2007, even though canopy cover and unstable banks had returned to 1997 levels. After several storm events in fall 2007, 10 years after the initial sediment input, fine sediment was flushed from the channels and returned to 1997 levels. Although our study design did not discern the source of the initial sediment inputs (e.g., forest harvest, road crossings, other natural causes), we have shown that moraine, headwater streams can require an extended period (up to 10 years) and enabling event (e.g., high storm flows) to recover from large inputs of fine sediment.

  9. Recovery of sediment characteristics in moraine, headwater streams of Northern Minnesota after forest harvest

    USGS Publications Warehouse

    Merten, Eric C.; Hemstad, Nathaniel A.; Kolka, Randall K.; Newman, Raymond M.; Verry, Elon S.; Vondracek, Bruce C.

    2010-01-01

    We investigated the recovery of sediment characteristics in four moraine, headwater streams in north-central Minnesota after forest harvest. We examined changes in fine sediment levels from 1997 (preharvest) to 2007 (10 years postharvest) at study plots with upland clear felling and riparian thinning, using canopy cover, proportion of unstable banks, surficial fine substrates, residual pool depth, and streambed depth of refusal as response variables. Basin-scale year effects were significant (p < 0.001) for all responses when evaluated by repeated-measures ANOVAs. Throughout the study area, unstable banks increased for several years postharvest, coinciding with an increase in windthrow and fine sediment. Increased unstable banks may have been caused by forest harvest equipment, increased windthrow and exposure of rootwads, or increased discharge and bank scour. Fine sediment in the channels did not recover by summer 2007, even though canopy cover and unstable banks had returned to 1997 levels. After several storm events in fall 2007, 10 years after the initial sediment input, fine sediment was flushed from the channels and returned to 1997 levels. Although our study design did not discern the source of the initial sediment inputs (e.g., forest harvest, road crossings, other natural causes), we have shown that moraine, headwater streams can require an extended period (up to 10 years) and enabling event (e.g., high storm flows) to recover from large inputs of fine sediment.

  10. Investigation of the Relative Effects of Insolation, Groundwater, and Spatial Variability in Temperature Dynamics of Two Headwater Streams

    NASA Astrophysics Data System (ADS)

    Belica, L.; Caldwell, P. V.; Mitasova, H.; McCarter, J. B.; Smith, J.; Nelson, S. A. C.

    2015-12-01

    Forested headwater streams account for much of the aquatic species diversity and contribute valuable recreational fisheries in the mountains of the Southeastern United States. Stream temperature is key regulator of headwater ecosystems and thermal regime is such a critical factor that it limits where many species can survive, grow, and successfully reproduce. Forested headwater streams are dynamic systems located in complex terrain. The variability of heat exchange between a stream and its surroundings results in thermal variations along its course. Understanding the spatial variability of heat fluxes along headwater streams is important to understanding the thermal dynamics and their effects on the biota. Solar radiation and groundwater inflow are two primary components of the heat budget of headwater streams and are spatially variable over short distances. A comparative analysis of north-facing and south-facing watersheds the Coweeta Basin of the Southern Appalachian Mountains found that temperatures of north-facing streams were cooler than south-facing streams for most of the year, but were warmer in summer. A north-south watershed pair with similar discharge, drainage areas, elevation, slope, and landcover characteristics was selected for further study. Water temperature was monitored longitudinally from the stream origins to the outlets beginning in late 2014. Preliminary data suggested variation in solar radiation resulting from the spatial heterogeneity of evergreen and deciduous trees and seasonal changes in leaf density could explain temperature patterns. We used the Subcanopy Solar Radiation Model, which accounts for topographic and vegetative shading by using a light penetration index derived from LIDAR data, to produce spatially explicit estimates of solar radiation and elucidate spatial and temporal variations in solar radiation along the two streams. Groundwater influence on stream temperature dynamics was investigated using salt-dilution gaging

  11. Salamander occupancy in headwater stream networks

    USGS Publications Warehouse

    Grant, E.H.C.; Green, L.E.; Lowe, W.H.

    2009-01-01

    1. Stream ecosystems exhibit a highly consistent dendritic geometry in which linear habitat units intersect to create a hierarchical network of connected branches. 2. Ecological and life history traits of species living in streams, such as the potential for overland movement, may interact with this architecture to shape patterns of occupancy and response to disturbance. Specifically, large-scale habitat alteration that fragments stream networks and reduces connectivity may reduce the probability a stream is occupied by sensitive species, such as stream salamanders. 3. We collected habitat occupancy data on four species of stream salamanders in first-order (i.e. headwater) streams in undeveloped and urbanised regions of the eastern U.S.A. We then used an information-theoretic approach to test alternative models of salamander occupancy based on a priori predictions of the effects of network configuration, region and salamander life history. 4. Across all four species, we found that streams connected to other first-order streams had higher occupancy than those flowing directly into larger streams and rivers. For three of the four species, occupancy was lower in the urbanised region than in the undeveloped region. 5. These results demonstrate that the spatial configuration of stream networks within protected areas affects the occurrences of stream salamander species. We strongly encourage preservation of network connections between first-order streams in conservation planning and management decisions that may affect stream species.

  12. Exploring groundwater processes in Rocky Mountain headwaters

    NASA Astrophysics Data System (ADS)

    Janzen, D.; Ireson, A. M.; Yassin, F. A.

    2014-12-01

    More than one-sixth of the Earth's human population relies on freshwater originating in mountain headwaters, which is understood to be generated largely from snowpacks that melt throughout the spring and summer. Annual hydrographs in these regions are characterized by large peaks occurring in the spring, followed by slow recession towards winter baseflow conditions. However, atmospheric warming trends are found to coincide with earlier periods of snowmelt, leading to increased flows in spring and decreased flows in summer. This decreased ability of our 'water towers' to store snow late into the summer suggests that other mechanisms of storage and release may become more important in sustaining baseflows. In particular, subsurface processes leading to late summer and winter flow will become increasingly important earlier on, but are as yet poorly understood. By utilising historical data to inform a better understanding of late-season subsurface processes, we will be better prepared to predict how these mountains will temporarily store and release groundwater in a warmer climate. Here, we analyse long-term data sets from a small (Marmot Creek, Alberta ~10 km2) and a large (Bow River at Banff, Alberta ~1000 km2) basinwithin the Canadian Rocky Mountains, comparing observations with model outputs, to investigate late-season hydrological responses, and particularly the role of groundwater as a temporary storage mechanism.

  13. Effective discharge in Rocky Mountain headwater streams

    NASA Astrophysics Data System (ADS)

    Bunte, Kristin; Abt, Steven R.; Swingle, Kurt W.; Cenderelli, Dan A.

    2014-11-01

    Whereas effective discharge (Qeff) in mountain streams is commonly associated with a moderate flow such as bankfull discharge (Qbf), this study found that the maximum discharge (Qmax), and not bankfull discharge, is the channel forming or effective flow for gravel transport in plane-bed streams where partial bed mobility causes steep gravel transport rating curves. Qeff may approach bankfull flow in some step-pool channels where gravel moves over a static cobble/boulder bed. Our conclusions are based on magnitude-frequency analyses conducted at 41 gauged Rocky Mountain headwater streams. Because these gauged streams lacked gravel transport data, as is typical, comparable streams with measured transport rates were used to develop scaling relations for rating curve exponents with stream and watershed characteristics. Those scaling relations were then used to estimate the steepness of gravel rating curves at the 41 gauged but unsampled sites. The measured flow frequency distributions were characterized by two fitted power functions. The steepness of the flow frequency distributions and the estimated steepness of gravel transport relations were combined in magnitude-frequency analyses to compute Qeff.

  14. Contaminated sediment dynamics in peatland headwaters

    NASA Astrophysics Data System (ADS)

    Shuttleworth, Emma; Clay, Gareth; Evans, Martin; Hutchinson, Simon; Rothwell, James

    2016-04-01

    Peatlands are an important store of soil carbon, provide multiple ecosystem services, and when located in close proximity to urban and industrial areas, can also act as sinks of atmospherically deposited heavy metals. The near-surface layer of the blanket peats of the Peak District National Park, UK, is severely contaminated with high concentrations of anthropogenically derived, atmospherically deposited lead (Pb). These peats are severely degraded, and there is increasing concern that erosion is releasing considerable quantities of this legacy pollution into surface waters. Despite substantial research into Pb dynamics in peatlands formal description of the possible mechanisms of contaminated sediment mobilisation is limited. However, there is evidence to suggest that a substantial proportion of contaminated surface sediment may be redistributed elsewhere in the catchment. This study uses the Pb contamination stored near the peat's surface as a fingerprint to trace contaminated sediment dynamics and storage in three severely degraded headwater catchments. Erosion is exposing high concentrations of Pb on interfluve surfaces, and substantial amounts of reworked contaminated material are stored on other catchment surfaces (gully walls and floors). We propose a variety of mechanisms as controls of Pb release and storage on the different surfaces, including: (i) wind action on interfluves; (ii) the aspect of gully walls, and (iii) gully depth. Vegetation also plays an important role in retaining contaminated sediment on all surfaces.

  15. Leaky rivers: Implications of the loss of longitudinal fluvial disconnectivity in headwater streams

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen; Beckman, Natalie D.

    2014-01-01

    Naturally induced longitudinal disconnectivity in the form of channel-spanning logjams creates backwaters along headwater streams that reduce velocity and transport capacity, create at least temporary storage sites for finer sediment and organic matter, and enhance biological processing and uptake of nutrients. Land uses that reduce wood recruitment and instream storage result in reduced stream complexity and increased longitudinal connectivity in headwater rivers. We examine three scales of naturally occurring longitudinal disconnectivity in headwater streams of the Colorado Front Range and the implications for channel process and form of historical alterations in disconnectivity. Basin-scale disconnectivity at channel lengths of 102-103 m results from downstream alternations between steep, narrowly confined valley segments with single-thread channels, and lower gradient, wider, valley segments with multi-thread channels. This variation in valley geometry likely reflects differences in average spacing between joints in bedrock outcrops, which influences bedrock weathering and erosion. Greater volumes of wood stored in the wide valley segments correlate with more closely spaced channel-spanning logjams and greater storage of fine sediments and organic matter. Reach-scale disconnectivity at channel lengths of 101-102 m results from the presence of numerous, closely spaced channel-spanning logjams, which cumulatively store substantial amounts of fine sediment and organic matter. The backwater effects associated with an individual jam can result in the accumulation of up to ~ 11 m3 of fine sediment upstream from the jam, of which as much as 21% is organic matter. Unit-scale disconnectivity at channel lengths of 100-101 m results from the presence of an individual channel-spanning logjam, which locally alters bed gradient, substrate composition, bedform dimensions, and the transport of sediment and organic matter. The transport and storage of instream wood is a

  16. Runoff responses to forest thinning at plot and catchment scales in a headwater catchment draining Japanese cypress forest

    NASA Astrophysics Data System (ADS)

    Dung, Bui Xuan; Gomi, Takashi; Miyata, Shusuke; Sidle, Roy C.; Kosugi, Kenichiro; Onda, Yuichi

    2012-06-01

    SummaryWe examined the effect of forest thinning on runoff generation at plot and catchment scales in headwater basins draining a Japanese cypress (Chamaecyparis obtusa) forest. We removed 58.3% of the stems (corresponding to 43.2% of the basal area) in the treated headwater basin (catchment M5), and left the control catchment (M4) untreated. In both catchments, we monitored overland flow from hillslope plots and stream runoff from catchments at basin outlets over a 2-year pre-thinning period and a 2-year post-thinning period. Paired catchment analysis revealed that annual catchment runoff increased 240.7 mm after thinning. Delayed runoff increased significantly, while quick runoff followed similar patterns in the pre- and post-thinning periods. Flow duration in the ephemeral channel in catchment M5 increased from 56.9% in the pre-thinning period to 73.3% in the post-thinning period. Despite the changes in hydrological responses at the catchment scale, increases in overland flow were not significant. The increased availability of water in the soil matrix, caused by decreased interception loss and evapotranspiration, increased base flow after thinning. Based on the summarized data of previous studies together with this study, the effects of forest thinning on increases in runoff were less than partial harvesting in which the managed areas were concentrated within a watershed. We demonstrated that the effect of forest thinning was strongly scale dependent, an important finding for optimizing water and forest management in forested watersheds.

  17. Dam removal increases American eel abundance in distant headwater streams

    USGS Publications Warehouse

    Hitt, Nathaniel P.; Eyler, Sheila; Wofford, John E.B.

    2012-01-01

    American eel Anguilla rostrata abundances have undergone significant declines over the last 50 years, and migration barriers have been recognized as a contributing cause. We evaluated eel abundances in headwater streams of Shenandoah National Park, Virginia, to compare sites before and after the removal of a large downstream dam in 2004 (Embrey Dam, Rappahannock River). Eel abundances in headwater streams increased significantly after the removal of Embrey Dam. Observed eel abundances after dam removal exceeded predictions derived from autoregressive models parameterized with data prior to dam removal. Mann–Kendall analyses also revealed consistent increases in eel abundances from 2004 to 2010 but inconsistent temporal trends before dam removal. Increasing eel numbers could not be attributed to changes in local physical habitat (i.e., mean stream depth or substrate size) or regional population dynamics (i.e., abundances in Maryland streams or Virginia estuaries). Dam removal was associated with decreasing minimum eel lengths in headwater streams, suggesting that the dam previously impeded migration of many small-bodied individuals (<300 mm TL). We hypothesize that restoring connectivity to headwater streams could increase eel population growth rates by increasing female eel numbers and fecundity. This study demonstrated that dams may influence eel abundances in headwater streams up to 150 river kilometers distant, and that dam removal may provide benefits for eel management and conservation at the landscape scale.

  18. Dissolved organic carbon export and internal cycling in small, headwater lakes

    USGS Publications Warehouse

    Stets, Edward G.; Striegl, Robert G.; Aiken, George R.

    2010-01-01

    Carbon (C) cycling in freshwater lakes is intense but poorly integrated into our current understanding of overall C transport from the land to the oceans. We quantified dissolved organic carbon export (DOCX) and compared it with modeled gross DOC mineralization (DOCR) to determine whether hydrologic or within-lake processes dominated DOC cycling in a small headwaters watershed in Minnesota, USA. We also used DOC optical properties to gather information about DOC sources. We then compared our results to a data set of approximately 1500 lakes in the Eastern USA (Eastern Lake Survey, ELS, data set) to place our results in context of lakes more broadly. In the open-basin lakes in our watershed (n = 5), DOCX ranged from 60 to 183 g C m−2 lake area yr−1, whereas DOCR ranged from 15 to 21 g C m−2 lake area yr−1, emphasizing that lateral DOC fluxes dominated. DOCX calculated in our study watershed clustered near the 75th percentile of open-basin lakes in the ELS data set, suggesting that these results were not unusual. In contrast, DOCX in closed-basin lakes (n = 2) was approximately 5 g C m−2 lake area yr−1, whereas DOCR was 37 to 42 g C m−2 lake area yr−1, suggesting that internal C cycling dominated. In the ELS data set, median DOCX was 32 and 12 g C m−2 yr−1 in open-basin and closed-basin lakes, respectively. Although not as high as what was observed in our study watershed, DOCX is an important component of lake C flux more generally, particularly in open-basin lakes.

  19. Environmental controls, rates and sedimentary mass transfers of contemporary slope processes in the headwater areas of two mountain valleys in western Norway

    NASA Astrophysics Data System (ADS)

    Laute, Katja; Beylich, Achim A.

    2014-05-01

    The role of hillslopes, functioning as key elements for sediment production, storage and transfers, is particularly important within headwater systems in cold climate mountain landscapes which are considered to react sensitively to climate change and human impact. This study provides a first detailed and systematic quantification of denudational slope processes as well as a sediment budget for the headwater systems of two steep mountain valleys located in western Norway. The focus of this study is on (i) contemporary geomorphic process rates and sedimentary mass transfers within the headwater areas of the drainage basins Erdalen (79.5 km2) and Bødalen (60.1 km2), (ii) the absolute and relative importance of the identified relevant denudational slope processes, and (iii) the importance of sediment delivery from slope systems into headwater main stream channels within the sedimentary budgets of the headwater systems. Identified relevant contemporary processes in both drainage basins include rock and boulder falls, snow avalanches, slush flows, debris flows, slow mass movements/creep processes, wash- and chemical denudation and fluvial transport of solutes, suspended sediments and bedload. These denudational processes were analyzed based on an extensive geomorphic monitoring program conducted over a period of four years (2009-2012) combined with detailed geomorphological mapping and in-depth studies of the most important slope processes. A range of different monitoring and field techniques was applied. Results show that the intensity of contemporary denudational processes in Erdalen and Bødalen are rather low and appear to be in a comparable range of magnitude as in a number of other cold climate environments situated at higher latitudes of the northern hemisphere. The present-day spatio-temporal pattern of denudational slope processes occurring in the headwater systems is controlled by a complex combination of meteorological and morphometric factors. Comparing the

  20. Conservation implications of amphibian habitat relationships within channelized agricultural headwater streams in the midwestern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The widespread use of stream channelization and subsurface tile drainage for removing water from agricultural fields has led to the development of numerous channelized agricultural headwater streams within agricultural watersheds of the Midwestern United States. Channelized agricultural headwater s...

  1. Relationship Between Watershed Land Use and Denitrification Enzyme Activity in Headwater Streams

    EPA Science Inventory

    Headwater streams are the dominant land-water interface across much of the landscape. Denitrification is an important ecological service provided by headwater streams. Anthropogenic inputs of N to terrestrial ecosystems largely result from agricultural practices. Animal agricultu...

  2. Runoff of small rocky headwater catchments: Field observations and hydrological modeling

    NASA Astrophysics Data System (ADS)

    Gregoretti, C.; Degetto, M.; Bernard, M.; Crucil, G.; Pimazzoni, A.; De Vido, G.; Berti, M.; Simoni, A.; Lanzoni, S.

    2016-10-01

    In dolomitic headwater catchments, intense rainstorms of short duration produce runoff discharges that often trigger debris flows on the scree slopes at the base of rock cliffs. In order to measure these discharges, we placed a measuring facility at the outlet (elevation 1770 m a.s.l.) of a small, rocky headwater catchment (area ˜0.032 km2, average slope ˜320%) located in the Venetian Dolomites (North Eastern Italian Alps). The facility consists of an approximately rectangular basin, ending with a sharp-crested weir. Six runoff events were recorded in the period 2011-2014, providing a unique opportunity for characterizing the hydrological response of the catchment. The measured hydrographs display impulsive shapes, with an abrupt raise up to the peak, followed by a rapidly decreasing tail, until a nearly constant plateau is eventually reached. This behavior can be simulated by means of a distributed hydrological model if the excess rainfall is determined accurately. We show that using the Soil Conservation Service Curve-Number (SCS-CN) method and assuming a constant routing velocity invariably results in an underestimated peak flow and a delayed peak time. A satisfactory prediction of the impulsive hydrograph shape, including peak value and timing, is obtained only by combining the SCS-CN procedure with a simplified version of the Horton equation, and simulating runoff routing along the channel network through a matched diffusivity kinematic wave model. The robustness of the proposed methodology is tested through a comparison between simulated and observed timings of runoff or debris flow occurrence in two neighboring alpine basins.

  3. 78 FR 78717 - Reservoirs at Headwaters of the Mississippi River; Use and Administration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... known as the Mississippi River Headwaters Reservoir Operating Plan Evaluation (ROPE). The primary purpose of the ROPE was to evaluate alternative operating plans for the Headwaters reservoirs in an... Record of Decision approving the ROPE's recommended operating plan for the Headwaters reservoirs....

  4. Effects of evapotranspiration on baseflow in a tropical headwater catchment

    NASA Astrophysics Data System (ADS)

    Cadol, Daniel; Kampf, Stephanie; Wohl, Ellen

    2012-09-01

    SummaryDiel cycles in stream discharge during baseflow periods in a headwater stream in La Selva Biological Station, Costa Rica, a tropical wet forest site, appear to be associated with groundwater withdrawal by the forest for evapotranspiration (ET). Analysis of the cycles indicates a strong correlation of stage change with ET demand, similar to the variation found in riparian water table elevation by previous researchers. Links between daily forest ET demand cycles and stream discharge cycles have been reported in temperate humid and semi-arid regions, but the frequent flood hydrographs of the wet tropics tend to obscure this daily signal. This study modifies and combines two established empirical methods for analyzing the diel ET signal in streamflow which lead to estimates of riparian ET derived from groundwater (ETG) at hourly time scales and spatial extent of the riparian area. The model has a direct dependence on the estimate of specific yield, a difficult to constrain parameter, which we estimate from previously published soil analyses. For the six baseflow periods analyzed, the model estimates groundwater ET losses ranging from 1.8 to 3.9 mm/day within the riparian area. These estimates are 52-81% of the total ET estimated with the Penman-Monteith equation (ETPM). The signal of ETG in the stream lags ETPM by 1.5-3 h, with apparent peak decay and signal duration lengthening during propagation. Model results indicate that the area of the riparian zone that influences streamflow by means of ET withdrawal increases with stream stage and ranges from 2.5% to 6.6% of the total basin area. Variations in the rate of change of nightly stream stage recovery suggest possible variations in the relative importance of subsurface hydraulic properties. At high stages, the rate of stream stage recovery from ET losses decreases throughout the night, whereas at low stages the rate of stream stage recovery increases throughout the night. Future work with numerical models could

  5. The Role of Headwater Streams in Downstream Water Quality.

    PubMed

    Alexander, Richard B; Boyer, Elizabeth W; Smith, Richard A; Schwarz, Gregory E; Moore, Richard B

    2007-02-01

    Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water-quality model to investigate headwater influences on downstream receiving waters. Our evaluations demonstrate the intrinsic connections of headwaters to landscape processes and downstream waters through their influence on the supply, transport, and fate of water and solutes in watersheds. Hydrological processes in headwater catchments control the recharge of subsurface water stores, flow paths, and residence times of water throughout landscapes. The dynamic coupling of hydrological and biogeochemical processes in upland streams further controls the chemical form, timing, and longitudinal distances of solute transport to downstream waters. We apply the spatially explicit, mass-balance watershed model SPARROW to consider transport and transformations of water and nutrients throughout stream networks in the northeastern United States. We simulate fluxes of nitrogen, a primary nutrient that is a water-quality concern for acidification of streams and lakes and eutrophication of coastal waters, and refine the model structure to include literature observations of nitrogen removal in streams and lakes. We quantify nitrogen transport from headwaters to downstream navigable waters, where headwaters are defined within the model as first-order, perennial streams that include flow and nitrogen contributions from smaller, intermittent and ephemeral streams. We find that first-order headwaters contribute approximately 70% of the mean-annual water volume and 65% of the nitrogen flux in second-order streams. Their contributions to mean water volume and nitrogen flux decline only marginally to about 55% and

  6. The Role of Headwater Streams in Downstream Water Quality1

    PubMed Central

    Alexander, Richard B; Boyer, Elizabeth W; Smith, Richard A; Schwarz, Gregory E; Moore, Richard B

    2007-01-01

    Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water-quality model to investigate headwater influences on downstream receiving waters. Our evaluations demonstrate the intrinsic connections of headwaters to landscape processes and downstream waters through their influence on the supply, transport, and fate of water and solutes in watersheds. Hydrological processes in headwater catchments control the recharge of subsurface water stores, flow paths, and residence times of water throughout landscapes. The dynamic coupling of hydrological and biogeochemical processes in upland streams further controls the chemical form, timing, and longitudinal distances of solute transport to downstream waters. We apply the spatially explicit, mass-balance watershed model SPARROW to consider transport and transformations of water and nutrients throughout stream networks in the northeastern United States. We simulate fluxes of nitrogen, a primary nutrient that is a water-quality concern for acidification of streams and lakes and eutrophication of coastal waters, and refine the model structure to include literature observations of nitrogen removal in streams and lakes. We quantify nitrogen transport from headwaters to downstream navigable waters, where headwaters are defined within the model as first-order, perennial streams that include flow and nitrogen contributions from smaller, intermittent and ephemeral streams. We find that first-order headwaters contribute approximately 70% of the mean-annual water volume and 65% of the nitrogen flux in second-order streams. Their contributions to mean water volume and nitrogen flux decline only marginally to about 55% and

  7. The role of headwater streams in downstream water quality

    USGS Publications Warehouse

    Alexander, R.B.; Boyer, E.W.; Smith, R.A.; Schwarz, G.E.; Moore, R.B.

    2007-01-01

    Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water-quality model to investigate headwater influences on downstream receiving waters. Our evaluations demonstrate the intrinsic connections of headwaters to landscape processes and downstream waters through their influence on the supply, transport, and fate of water and solutes in watersheds. Hydrological processes in headwater catchments control the recharge of subsurface water stores, flow paths, and residence times of water throughout landscapes. The dynamic coupling of hydrological and biogeochemical processes in upland streams further controls the chemical form, timing, and longitudinal distances of solute transport to downstream waters. We apply the spatially explicit, mass-balance watershed model SPARROW to consider transport and transformations of water and nutrients throughout stream networks in the northeastern United States. We simulate fluxes of nitrogen, a primary nutrient that is a water-quality concern for acidification of streams and lakes and eutrophication of coastal waters, and refine the model structure to include literature observations of nitrogen removal in streams and lakes. We quantify nitrogen transport from headwaters to downstream navigable waters, where headwaters are defined within the model as first-order, perennial streams that include flow and nitrogen contributions from smaller, intermittent and ephemeral streams. We find that first-order headwaters contribute approximately 70% of the mean-annual water volume and 65% of the nitrogen flux in second-order streams. Their contributions to mean water volume and nitrogen flux decline only marginally to about 55% and

  8. Postglacial adjustment of steep, low-order drainage basins, Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Hoffmann, T.; Müller, T.; Johnson, E. A.; Martin, Y. E.

    2013-12-01

    is generally argued that Pleistocene glaciation results in increased sediment flux in mountain systems. An important, but not well constrained, aspect of Pleistocene glacial erosion is the geomorphic decoupling of cirque basins from main river systems. This study provides a quantitative link between glacier-induced basin morphology, postglacial erosion, and sediment delivery for mountain headwaters (with basin area <10 km2). We analyze the morphology of 57 headwater basins in the Canadian Rockies and establish postglacial sediment budgets for select basins. Notable differences in headwater morphology suggest different degrees of erosion by cirque glaciers, which we classify into headwater basins with either cirque or noncirque morphology. Despite steeper slope gradients in cirque basins, higher-mean postglacial erosion rates in basins with noncirque morphology (0.43-0.6 mm a-1) compared to those in cirques (0.19-0.39 mm a-1) suggest a more complex relationship between hillslope erosion and slope gradient in calcareous mountain environments than implied by the threshold hillslope concept. Higher values of channel profile concavity and lower channel gradients in cirques imply lower transport capacities and, thus, lower sediment delivery ratios (SDR). These results are supported by (i) postglacial SDR values for cirques and noncirque basins of <15% and >28%, respectively, and (ii) larger fan sizes at outlets of noncirque basins compared to cirques. Although small headwater basins represent the steepest part of mountain environments and erode significant postglacial sediment, the majority of sediment remains in storage under interglacial climatic conditions and does not affect large-scale mountain river systems.

  9. Surface fluxes and water balance of spatially varying vegetation within a small mountainous headwater catchment

    NASA Astrophysics Data System (ADS)

    Flerchinger, G. N.; Marks, D.; Reba, M. L.; Yu, Q.; Seyfried, M. S.

    2010-06-01

    Precipitation variability and complex topography often create a mosaic of vegetation communities in mountainous headwater catchments, creating a challenge for measuring and interpreting energy and mass fluxes. Understanding the role of these communities in modulating energy, water and carbon fluxes is critical to quantifying the variability in energy, carbon, and water balances across landscapes. The focus of this paper was: (1) to demonstrate the utility of eddy covariance (EC) systems in estimating the evapotranspiration component of the water balance of complex headwater mountain catchments; and (2) to compare and contrast the seasonal surface energy and carbon fluxes across a headwater catchment characterized by large variability in precipitation and vegetation cover. Eddy covariance systems were used to measure surface fluxes over sagebrush (Artemesia arbuscula and Artemesia tridentada vaseyana), aspen (Populus tremuloides) and the understory of grasses and forbs beneath the aspen canopy. Peak leaf area index of the sagebrush, aspen, and aspen understory was 0.77, 1.35, and 1.20, respectively. The sagebrush and aspen canopies were subject to similar meteorological forces, while the understory of the aspen was sheltered from the wind. Missing periods of measured data were common and made it necessary to extrapolate measured fluxes to the missing periods using a combination of measured and simulated data. Estimated cumulative evapotranspiratation from the sagebrush, aspen trees, and aspen understory were 384 mm, 314 mm and 185 mm. A water balance of the catchment indicated that of the 699 mm of areal average precipitation, 421 mm was lost to evapotranspiration, and 254 mm of streamflow was measured from the catchment; water balance closure for the catchment was within 22 mm. Fluxes of latent heat and carbon for all sites were minimal through the winter. Growing season fluxes of latent heat and carbon were consistently higher above the aspen canopy than from the

  10. Headwaters: The Next Stage in High School Integrated Programming

    ERIC Educational Resources Information Center

    Elrick, Mike

    2010-01-01

    In 2006, the grade 12 program "Headwaters" was initiated and offered the following four courses: (1) Environment and Resource Management; (2) Canadian Literature; (3) Outdoor Activities; and (4) Interdisciplinary Studies. The author has always described the program as simply "school." The teachers teach curriculum courses…

  11. BIOLOGICAL INTEGRITY IN MID-ATLANTIC COASTAL PLAINS HEADWATER STREAMS

    EPA Science Inventory

    The objective of this study was to assess the applicability of using landscape variables in conjunction with water quality and benthic data to efficiently estimate stream condition of select headwater streams in the Mid-Atlantic Coastal Plains. Eighty-two streams with riffle sit...

  12. An ecosystem services framework for multidisciplinary research in the Colorado River headwaters

    USGS Publications Warehouse

    Semmens, D.J.; Briggs, J.S.; Martin, D.A.

    2009-01-01

    A rapidly spreading Mountain Pine Beetle epidemic is killing lodgepole pine forest in the Rocky Mountains, causing landscape change on a massive scale. Approximately 1.5 million acres of lodgepoledominated forest is already dead or dying in Colorado, the infestation is still spreading rapidly, and it is expected that in excess of 90 percent of all lodgepole forest will ultimately be killed. Drought conditions combined with dramatically reduced foliar moisture content due to stress or mortality from Mountain Pine Beetle have combined to elevate the probability of large fires throughout the Colorado River headwaters. Large numbers of homes in the wildland-urban interface, an extensive water supply infrastructure, and a local economy driven largely by recreational tourism make the potential costs associated with such a fire very large. Any assessment of fire risk for strategic planning of pre-fire management actions must consider these and a host of other important socioeconomic benefits derived from the Rocky Mountain Lodgepole Pine Forest ecosystem. This paper presents a plan to focus U.S. Geological Survey (USGS) multidisciplinary fire/beetle-related research in the Colorado River headwaters within a framework that integrates a wide variety of discipline-specific research to assess and value the full range of ecosystem services provided by the Rocky Mountain Lodgepole Pine Forest ecosystem. Baseline, unburned conditions will be compared with a hypothetical, fully burned scenario to (a) identify where services would be most severely impacted, and (b) quantify potential economic losses. Collaboration with the U.S. Forest Service will further yield a distributed model of fire probability that can be used in combination with the ecosystem service valuation to develop comprehensive, distributed maps of fire risk in the Upper Colorado River Basin. These maps will be intended for use by stakeholders as a strategic planning tool for pre-fire management activities and can

  13. Imaging Hydrological Processes in Headwater Riparian Seeps with Time-Lapse Electrical Resistivity.

    PubMed

    Williams, Mark R; Buda, Anthony R; Singha, Kamini; Folmar, Gordon J; Elliott, Herschel A; Schmidt, John P

    2017-01-01

    Delineating hydrologic and pedogenic factors influencing groundwater flow in riparian zones is central in understanding pathways of water and nutrient transport. In this study, we combined two-dimensional time-lapse electrical resistivity imaging (ERI) (depth of investigation approximately 2 m) with hydrometric monitoring to examine hydrological processes in the riparian area of FD-36, a small (0.4 km(2) ) agricultural headwater basin in the Valley and Ridge region of east-central Pennsylvania. We selected two contrasting study sites, including a seep with groundwater discharge and an adjacent area lacking such seepage. Both sites were underlain by a fragipan at 0.6 m. We then monitored changes in electrical resistivity, shallow groundwater, and nitrate-N concentrations as a series of storms transitioned the landscape from dry to wet conditions. Time-lapse ERI revealed different resistivity patterns between seep and non-seep areas during the study period. Notably, the seep displayed strong resistivity reductions (∼60%) along a vertically aligned region of the soil profile, which coincided with strong upward hydraulic gradients recorded in a grid of nested piezometers (0.2- and 0.6-m depth). These patterns suggested a hydraulic connection between the seep and the nitrate-rich shallow groundwater system below the fragipan, which enabled groundwater and associated nitrate-N to discharge through the fragipan to the surface. In contrast, time-lapse ERI indicated no such connections in the non-seep area, with infiltrated rainwater presumably perched above the fragipan. Results highlight the value of pairing time-lapse ERI with hydrometric and water quality monitoring to illuminate possible groundwater and nutrient flow pathways to seeps in headwater riparian areas.

  14. Fish communities of the Buffalo River Basin and nearby basins of Arkansas and their relation to selected environmental factors, 2001-2002

    USGS Publications Warehouse

    Petersen, James C.

    2004-01-01

    The Buffalo River lies in north-central Arkansas and is a tributary of the White River. Most of the length of the Buffalo River lies within the boundaries of Buffalo National River, a unit of the National Park Service; the upper 24 river kilometers lie within the boundary of the Ozark National Forest. Much of the upper and extreme lower parts of the basin on the south side of the Buffalo River is within the Ozark National Forest. During the summers of 2001 and 2002, fish communities were sampled at 52 sites in the study area that included the Buffalo River Basin and selected smaller nearby basins within the White River Basin in north-central Arkansas. Water quality (including nutrient and bacteria concentrations) and several other environmental factors (such as stream size, land use, substrate size, and riparian shading) also were measured. A total of 56 species of fish were collected from sites within the Buffalo River Basin in 2001 and 2002. All 56 species also were collected from within the boundaries of Buffalo National River. Twenty-two species were collected from headwater sites on tributaries of the Buffalo River; 27 species were collected from sites within or immediately adjacent to the Ozark National Forest. The list of species collected from Buffalo National River is similar to the list of species reported by previous investigators. Species richness at sites on the mainstem of the Buffalo River generally increased in a downstream direction. The number of species collected (both years combined) increased from 17 at the most upstream site to 38 near the mouth of the Buffalo River. In 2001 and 2002, a total of 53 species of fish were collected from sites outside the Buffalo River Basin. Several fish community metrics varied among sites in different site categories (mainstem, large tributary, small tributary, headwater, and developed out-of-basin sites). Median relative abundances of stonerollers ranged from about 25 to 55 percent and were highest at

  15. A process-based hierarchical framework for monitoring glaciated alpine headwaters

    USGS Publications Warehouse

    Weekes, Anne A.; Torgersen, Christian E.; Montgomery, David R.; Woodward, Andrea; Bolton, Susan M.

    2012-01-01

    Recent studies have demonstrated the geomorphic complexity and wide range of hydrologic regimes found in alpine headwater channels that provide complex habitats for aquatic taxa. These geohydrologic elements are fundamental to better understand patterns in species assemblages and indicator taxa and are necessary to aquatic monitoring protocols that aim to track changes in physical conditions. Complex physical variables shape many biological and ecological traits, including life history strategies, but these mechanisms can only be understood if critical physical variables are adequately represented within the sampling framework. To better align sampling design protocols with current geohydrologic knowledge, we present a conceptual framework that incorporates regional-scale conditions, basin-scale longitudinal profiles, valley-scale glacial macroform structure, valley segment-scale (i.e., colluvial, alluvial, and bedrock), and reach-scale channel types. At the valley segment- and reach-scales, these hierarchical levels are associated with differences in streamflow and sediment regime, water source contribution and water temperature. Examples of linked physical-ecological hypotheses placed in a landscape context and a case study using the proposed framework are presented to demonstrate the usefulness of this approach for monitoring complex temporal and spatial patterns and processes in glaciated basins. This approach is meant to aid in comparisons between mountain regions on a global scale and to improve management of potentially endangered alpine species affected by climate change and other stressors.

  16. Geomorphic (de-) coupling of hillslope and channel systems within headwater catchments in two subarctic tributary valleys, Nordfjord, Western Norway

    NASA Astrophysics Data System (ADS)

    Laute, Katja; Beylich, Achim A.

    2010-05-01

    Hillslopes occupy large areas of the earth surface. Studying the characteristics, development and interaction of hillslopes as components of the geomorphic hillslope-channel coupling process-response system will improve the understanding of the complex response of mountain landscape formation. The rates of hillslope processes are exceptionally varied and affected by many influences of varying intensity. Hillslope-channel coupling and sediment storage within slopes are important factors that influence sediment delivery through catchments, especially in steep environments. Within sediment transfers from sources to sinks in drainage basins, hillslopes function as a key element concerning sediment storage, both for short term periods as between rainstorms as well as for longer periods in colluvial deposits. This PhD project is part of the NFR funded SedyMONT-Norway project within the ESF TOPO-EUROPE SedyMONT (Timescales of sediment dynamics, climate and topographic change in mountain landscapes) programme. The focus of this study is on geomorphic hillslope-channel coupling or de-coupling and sediment transport within four distinct headwater areas of the Erdalen and Bødalen catchments in the Nordfjord valley-fjord system (inner Nordfjord, Western Norway). Both catchments can be described as steep, U-shaped and glacier-fed, subarctic tributary valleys. Approximately 14% of the 49 km2 large headwater area of Erdalen is occupied by hillslope deposits; in Bødalen hillslope deposits occupy 12% of the 42 km2 large headwater area. The main aims of the study are to present preliminary findings on (i) the identification of possible sediment sources and delivery pathways within the headwater areas of the catchments, (ii) to analyze the development of hillslope-channel coupling / de-coupling from postglacial to contemporary timescales as well as (iii) to investigate the current degree of geomorphic hillslope-channel coupling within the different headwater catchments and (iv) to

  17. Effect of ecological restoration and climate change on ecosystems: a case study in the Three-Rivers Headwater Region, China.

    PubMed

    Jiang, Chong; Zhang, Linbo

    2016-06-01

    The Three-Rivers Headwater Region (TRHR) is the headwater of the Yangtze River Basin (YARB), Yellow River Basin (YRB), and Lancang River Basin (LRB); it is known as China's 'Water Tower' owing to its important supply of freshwater. In order to assess ecosystem changes in the TRHR during 2000-2012, we systematically and comprehensively evaluated a combination of model simulation results and actual observational data. The results showed the following: (1) Ecosystem pattern was relatively stable during 2000-2010, with a slight decrease in farmland and desert areas, and a slight increase in grassland and wetland/water-body areas. (2) A warmer and wetter climate, and ecological engineering, caused the vegetation cover and productivity to significantly improve. (3) Precipitation was the main controlling factor for streamflow. A significant increase in precipitation during 2000-2012 resulted in an obvious increase in annual and seasonal streamflow. Glacier melting also contributed to the streamflow increase. (4) The total amount of soil conservation increased slightly from 2000 to 2012. The increase in precipitation caused rainfall erosivity to increase, which enhanced the intensity of soil erosion. The decrease in wind speed decreased wind erosion and the frequency of sandstorms. (5) The overall habitat quality in the TRHR was stable between 2000 and 2010, and the spatial pattern exhibited obvious heterogeneity. In some counties that included nature reserves, habitat quality was slightly higher in 2010 than in 2000, which reflected the effectiveness of the ecological restoration. Overall, the aforementioned ecosystem changes are the combined results of ecological restoration and climate change, and they are likely a local and temporary improvement, rather than a comprehensive and fundamental change. Therefore, more investments and efforts are needed to preserve natural ecosystems.

  18. Hydrology and Geomorphology of Tallgrass Prairie Intermittent Headwater Streams

    NASA Astrophysics Data System (ADS)

    Daniels, M. D.; Grudzinski, B.

    2011-12-01

    The arid to semi-arid Great Plains region of the United States covers more than 1 million km2, yet virtually nothing is known about the geomorphology of its intermittent headwater streams. These streams and the perennial rivers they feed support a unique and increasingly endangered assemblage of endemic fish species. While human impacts in the region are not at first glace significant, the reality is that the Great Plains are an intensively managed landscape, with pervasive cattle grazing, channelization, and groundwater over-pumping affecting these systems. These stresses will only increase with potential climate and related land use changes. Few natural remnants of native grassland remain today, limiting opportunities to study the natural dynamics of these systems in contrast to the anthropogenically modified systems. This paper presents a review of the existing geomorphological and hydrological knowledge of Great Plains headwater streams and presents the initial analysis of an 18 year intermittent headwater stream record from the tallgrass Konza Prairie LTER, Kansas. Results suggest that fire frequency and grazing and the resultant riparian vegetation composition strongly influence stream flow dynamics as well as stream geomorphology.

  19. Hydrologic connectivity and the contribution of stream headwaters to ecological integrity at regional scales

    USGS Publications Warehouse

    Freeman, Mary C.; Pringle, C.M.; Jackson, C.R.

    2007-01-01

    Cumulatively, headwater streams contribute to maintaining hydrologic connectivity and ecosystem integrity at regional scales. Hydrologic connectivity is the water-mediated transport of matter, energy and organisms within or between elements of the hydrologic cycle. Headwater streams compose over two-thirds of total stream length in a typical river drainage and directly connect the upland and riparian landscape to the rest of the stream ecosystem. Altering headwater streams, e.g., by channelization, diversion through pipes, impoundment and burial, modifies fluxes between uplands and downstream river segments and eliminates distinctive habitats. The large-scale ecological effects of altering headwaters are amplified by land uses that alter runoff and nutrient loads to streams, and by widespread dam construction on larger rivers (which frequently leaves free-flowing upstream portions of river systems essential to sustaining aquatic biodiversity). We discuss three examples of large-scale consequences of cumulative headwater alteration. Downstream eutrophication and coastal hypoxia result, in part, from agricultural practices that alter headwaters and wetlands while increasing nutrient runoff. Extensive headwater alteration is also expected to lower secondary productivity of river systems by reducing stream-system length and trophic subsidies to downstream river segments, affecting aquatic communities and terrestrial wildlife that utilize aquatic resources. Reduced viability of freshwater biota may occur with cumulative headwater alteration, including for species that occupy a range of stream sizes but for which headwater streams diversify the network of interconnected populations or enhance survival for particular life stages. Developing a more predictive understanding of ecological patterns that may emerge on regional scales as a result of headwater alterations will require studies focused on components and pathways that connect headwaters to river, coastal and

  20. Simulation of Climate Change Impacts on Himalayan Headwater Watershed Snowmelt Hydrology: Discharge, Sediment Load, and Nutrient Shifts

    NASA Astrophysics Data System (ADS)

    Neupane, R. P.; White, J. D.

    2010-12-01

    Due to retreat of glaciers and rapid population growth in associated watersheds, the Himalayas are important due to their potential for constraining water availability for a significant portion of the world’s population. Uncertainty exists in the derivation of water from the Himalayan headwaters due to shifts in meltwater derived from glaciers to transient snowpack under future climate change. Because hydrologic changes from headwater sources will also impact downstream reservoirs, we used the Soil and Water Assessment Tool (SWAT 2005) to simulate hydrologic discharge, sediment yield, and nutrient loading from the Narayani River Basin Watershed. This watershed is located in central Nepal that covers 31,986 km2 area, has 50% of the elevation>3000m, and is a major headwater basin for the Ganges River. We calibrated the SWAT model for this basin with surprising accuracy where simulated monthly average supply rate of water from watershed was 1568 cms compared to the observed value of 1589 cms. In this calibration process, we found that the precipitation and temperature lapse rates and effective hydraulic conductivity in main channel alluvium were the most important factors influencing predicted discharge values. Analysis of input landcover data showed that 5% of the watershed area is covered by glaciers and contributes approximately 15% of the discharge rate, mostly during summer months. This is contrasted to snowmelt which contributes only 4% to discharge rate during early spring based on our simulations. Future climate scenarios predicted by general circulation models for 2050 which showed increased stream discharge of 4%, 5% and 2% compared to current low, medium and high emission scenarios respectively. Sediment yield also increased by 17%, 26% and 17% compared to current for each emission scenario. Nutrient concentrations, including nitrogen and phosphorus, showed decreases under low emission scenarios and increases under medium and high emission scenarios. Our

  1. Influence of hillslope-channel coupling on two mountain headwater streams, Swiss National Park, Switzerland

    NASA Astrophysics Data System (ADS)

    Schoch, Anna; Hoffmann, Thomas; Dikau, Richard

    2014-05-01

    Sediment fluxes in mountain headwater streams are strongly conditioned by sediment supply from hillslopes and thus hillslope-channel coupling, defined as linkages connecting slopes and channels through sediment transport processes. Sediment supply from hillslopes can have major influences on channel characteristics. The main goal of my research is to achieve a better understanding of these influences on mountain headwater streams in two study areas. This is conducted through the investigation of "channel-reach morphology" according to MONTGOMERY AND BUFFINGTON (1997), morphometric and sedimentological characteristics of the channels and analysis of the slope-channel coupling system. The study was conducted in two valleys in the Swiss National Park, i.e. Val dal Botsch (VdB) and Val Mueschauns (VMu). In both headwaters slopes and channel are coupled effectively due to the small spatial vicinity and frequent debris flow processes connecting the two system components. Both catchments were glaciated in the Pleistocene but show contrasting glacial imprints today. While VdB has a V-shaped morphometry that is dominated by unconsolidated sediments (mainly talus and moraine material), VMu is U-shaped in the upper valley segments and the surface is mainly covered with bedrock. Several methods for data collection and analyses were used: (1) Channel-reach morphology classification, (2) DEM-based analysis of long profiles, ksn-values, slope-area plots and measurement of cross sections in the field, (3) investigation of sedimentological characteristics with pebble counts as well as (4) mapping of recent linkages between slopes and channel and determination of connectivity (effectivity of coupling) using a heuristic approach. The results show that sediment input into both headwater streams is dominated by debris flows. The debris flow catchments, as parts of the slope system, have the highest connectivity to the channels. Channel changes are greatest where debris flows cause

  2. Beyond Colorado's Front Range - A new look at Laramide basin subsidence, sedimentation, and deformation in north-central Colorado

    USGS Publications Warehouse

    Cole, James C.; Trexler, James H.; Cashman, Patricia H.; Miller, Ian M.; Shroba, Ralph R.; Cosca, Michael A.; Workman, Jeremiah B.

    2010-01-01

    This field trip highlights recent research into the Laramide uplift, erosion, and sedimentation on the western side of the northern Colorado Front Range. The Laramide history of the North Park?Middle Park basin (designated the Colorado Headwaters Basin in this paper) is distinctly different from that of the Denver basin on the eastern flank of the range. The Denver basin stratigraphy records the transition from Late Cretaceous marine shale to recessional shoreline sandstones to continental, fluvial, marsh, and coal mires environments, followed by orogenic sediments that span the K-T boundary. Upper Cretaceous and Paleogene strata in the Denver basin consist of two mega-fan complexes that are separated by a 9 million-year interval of erosion/non-deposition between about 63 and 54 Ma. In contrast, the marine shale unit on the western flank of the Front Range was deeply eroded over most of the area of the Colorado Headwaters Basin (approximately one km removed) prior to any orogenic sediment accumulation. New 40Ar-39Ar ages indicate the oldest sediments on the western flank of the Front Range were as young as about 61 Ma. They comprise the Windy Gap Volcanic Member of the Middle Park Formation, which consists of coarse, immature volcanic conglomerates derived from nearby alkalic-mafic volcanic edifices that were forming at about 65?61 Ma. Clasts of Proterozoic granite, pegmatite, and gneiss (eroded from the uplifted core of the Front Range) seem to arrive in the Colorado Headwaters Basin at different times in different places, but they become dominant in arkosic sandstones and conglomerates about one km above the base of the Colorado Headwaters Basin section. Paleocurrent trends suggest the southern end of the Colorado Headwaters Basin was structurally closed because all fluvial deposits show a northward component of transport. Lacustrine depositional environments are indicated by various sedimentological features in several sections within the >3 km of sediment

  3. Links between riparian landcover, instream environment and fish assemblages in headwater streams of south-eastern Brazil

    USGS Publications Warehouse

    Cruz, Bruna B.; Miranda, Leandro E.; Cetra, Mauricio

    2013-01-01

    We hypothesised and tested a hierarchical organisation model where riparian landcover would influence bank composition and light availability, which in turn would influence instream environments and control fish assemblages. The study was conducted during the dry season in 11 headwater tributaries of the Sorocaba River in the upper Paraná River Basin, south-eastern Brazil. We focused on seven environmental factors each represented by one or multiple environmental variables and seven fish functional traits each represented by two or more classes. Multivariate direct gradient analyses suggested that riparian zone landcover can be considered a higher level causal factor in a network of relations that control instream characteristics and fish assemblages. Our results provide a framework for a hierarchical conceptual model that identifies singular and collective influences of variables from different scales on each other and ultimately on different aspects related to stream fish functional composition. This conceptual model is focused on the relationships between riparian landcover and instream variables as causal factors on the organisation of stream fish assemblages. Our results can also be viewed as a model for headwater stream management in that landcover can be manipulated to influence factors such as bank composition, substrates and water quality, whereas fish assemblage composition can be used as indicators to monitor the success of such efforts.

  4. Ecological linkages between headwaters and downstream ecosystems: Transport of organic matter, invertebrates, and wood down headwater channels

    USGS Publications Warehouse

    Wipfli, M.S.; Richardson, J.S.; Naiman, R.J.

    2007-01-01

    Headwater streams make up a large proportion of the total length and watershed area of fluvial networks, and are partially characterized by the large volume of organic matter (large wood, detritus, and dissolved organic matter) and invertebrate inputs from the riparian forest, relative to stream size. Much of those inputs are exported to downstream reaches through time where they potentially subsidize river communities. The relative rates, timing, and conversion processes that carry inputs from small streams to downstream reaches are reasonably well quantified. For example, larger particles are converted to smaller particles, which are more easily exported. Also, dissolved organic matter and surface biofilms are converted to larger particles which can be more easily intercepted by consumers. However, the quality of these materials as it affects biological activity downstream is not well known, nor is the extent to which timing permits biological use of those particles. These ecological unknowns need to be resolved. Further, land uses may disrupt and diminish material transport to downstream reaches by removing sources (e.g., forest harvest), by affecting transport and decomposition processes (e.g., flow regulation, irrigation, changes in biotic communities), and by altering mechanisms of storage within headwaters (e.g., channelization). We present conceptual models of energy and nutrient fluxes that outline small stream processes and pathways important to downstream communities, and we identify informational gaps that, if filled, could significantly advance the understanding of linkages between headwater streams and larger rivers. The models, based on empirical evidence and best professional judgment, suggest that navigable waters are significantly influenced by headwater streams through hydrological and ecological connectivities, and land use can dramatically influence these natural connectivities, impacting downstream riverine ecosystems. ?? 2007 American Water

  5. Ecoregion and land-use influence invertebrate and detritus transport from headwater streams

    USGS Publications Warehouse

    Binckley, Christopher A.; Wipfli, Mark S.; Medhurst, R. Bruce; Polivka, Karl; Hessburg, Paul F.; Salter, R. Brion; Kill, Joshua Y.

    2010-01-01

    4. Understanding the quantity and variation of headwater subsidies across climate and disturbance gradients is needed to appreciate the significance of ecological linkages between headwaters and associated downstream habitats. This will enable the accurate assessment of resource management impacts on stream ecosystems. Predicting the consequences of natural and anthropogenic disturbances on headwater stream transport rates will require knowledge of how both local and regional factors influence these potential subsidies. Our results suggest that resources transported from headwater streams reflect both the meso-scale land-use surrounding these areas and the constraints imposed by the ecoregion in which they are embedded.

  6. Erosion, sediment discharge, and channel morphology in the upper Chattahoochee River basin, Georgia, with a discussion of the contribution of suspended sediment to stream quality

    USGS Publications Warehouse

    Faye, Robert E.; Carey, W.P.; Stamer, J.K.; Kleckner, R.L.

    1980-01-01

    The 3,550 square miles of the Upper Chattahoochee River basin is an area of diverse physiographic and land-use characteristics. The headwater areas are mountainous with steep, relatively narrow channels. Land in the headwater areas is heavily forested, but small towns and farms are common in the valleys of large streams. Downstream, the basin is characterized by low hills and wider stream channels. Land in this part of the basin is also predominantly forested; however, large agricultural and urban areas are common. Urban land use is particularly intensive within the Atlanta Metropolitan Area.

  7. Earth Science Studies in Support of Public Policy Development and Land Stewardship - Headwaters Province, Idaho and Montana

    USGS Publications Warehouse

    U.S. Geological Survey Headwaters Province Project Team Edited by Lund, Karen

    2007-01-01

    The USGS Headwaters Province project in western Montana and northern and central Idaho was designed to provide geoscience data and interpretations to Federal Land Management Agencies and to respond to specific concerns of USDA Forest Service Regions 1 and 4. The project has emphasized development of digital geoscience data, GIS analyses, topical studies, and new geologic interpretations. Studies were designed to more completely map lithologic units and determine controls of deformation, magmatism, and mineralizing processes. Topical studies of geologic basement control on these processes include study of regional metallogenic patterns and their relation to the composition and architecture of underlying, unexposed basement; timing of igneous and hydrothermal systems, to identify regionally important metallogenic magmatism; and the geologic setting of Proterozoic strata, to better understand how their sedimentary basins developed and to define the origin of sediment-hosted mineral deposits. Interrelated products of the project are at complementary scales.

  8. Influence of catchment land cover on stoichiometry and stable isotope compositions of basal resources and macroinvertebrate consumers in headwater streams

    EPA Science Inventory

    Anthropogenic land use affects aquatic landscapes. For example, landscape-level conversion to urban or agricultural land can heavily influence nutrient cycles in headwater streams via increased nutrient loading and altered hydrologic patterns. Recent studies in headwater streams ...

  9. Relative influence of different habitat factors on creek chub population structure within channelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Creek chubs (Semotilus atromaculatus) are commonly found within channelized agricultural headwater streams within the Midwestern United States. Understanding the relationships of this headwater fish species with different habitat factors will provide information that can assist with developing resto...

  10. Utilization of ancient permafrost carbon in headwaters of Arctic fluvial networks

    PubMed Central

    Mann, Paul J.; Eglinton, Timothy I.; McIntyre, Cameron P.; Zimov, Nikita; Davydova, Anna; Vonk, Jorien E.; Holmes, Robert M.; Spencer, Robert G. M.

    2015-01-01

    Northern high-latitude rivers are major conduits of carbon from land to coastal seas and the Arctic Ocean. Arctic warming is promoting terrestrial permafrost thaw and shifting hydrologic flowpaths, leading to fluvial mobilization of ancient carbon stores. Here we describe 14C and 13C characteristics of dissolved organic carbon from fluvial networks across the Kolyma River Basin (Siberia), and isotopic changes during bioincubation experiments. Microbial communities utilized ancient carbon (11,300 to >50,000 14C years) in permafrost thaw waters and millennial-aged carbon (up to 10,000 14C years) across headwater streams. Microbial demand was supported by progressively younger (14C-enriched) carbon downstream through the network, with predominantly modern carbon pools subsidizing microorganisms in large rivers and main-stem waters. Permafrost acts as a significant and preferentially degradable source of bioavailable carbon in Arctic freshwaters, which is likely to increase as permafrost thaw intensifies causing positive climate feedbacks in response to on-going climate change. PMID:26206473

  11. Annual and seasonal differences in pesticide mixtures within channelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Only a limited amount of information on pesticide mixtures within agricultural headwater streams is available. A greater understanding of the characteristics of pesticide mixtures and their spatial and temporal trends within agricultural headwater streams is needed to evaluate the risks of pesticid...

  12. Headwater effects on downstream waters: Legal perspectives, science needs, and assessment approaches

    EPA Science Inventory

    Headwater streams make up at least 53% of total stream length in the US. Although these systems are of interest for their own sake, there has recently been significant focus on how headwater streams contribute to downstream waters. This has resulted in part from recent legal op...

  13. Seasonal nitrate uptake and denitrification potential in small headwater streams in the Willamette Valley, Oregon

    EPA Science Inventory

    Background/Question/Methods Headwater streams can serve as important sources and sinks for nitrogen (N) for downstream receiving waters. Prior research on N removal in small streams has largely focused on growing season conditions. Here we examine the influence of headwater...

  14. Where Did All the Streams Go? Effects of Urbanization on Hydrologic Permanence of Headwater Streams

    EPA Science Inventory

    Headwater streams represent a majority (up to 70%) of the stream length in the United States; however, these small streams are often piped or filled to accommodate residential, commercial, and industrial development. Legal protection of headwater streams under the Clean Water Ac...

  15. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Mississippi River; use and administration. 207.340 Section 207.340 Navigation and Navigable Waters CORPS OF... headwaters of the Mississippi River; use and administration. (a) Description. These reservoirs include... use and administration of the reservoirs at the headwaters of the Mississippi River under date...

  16. DEVELOPMENT OF BIOLOGICAL INDICATORS, METHODS AND ASSESSMENT TECHNIQUES FOR USE IN HEADWATER INTERMITTENT STREAMS

    EPA Science Inventory

    Despite representing the most abundant and widespread of our nation's surface waters, regions, states and tribes have received little guidance specific to headwater intermittent streams from the U.S. EPA. Headwater streams lie at the terrestrial-aquatic interface both spatially,...

  17. Emissions of carbon dioxide and methane from a headwater stream network of interior Alaska

    USGS Publications Warehouse

    Crawford, John T.; Striegl, Robert G.; Wickland, Kimberly P.; Dornblaser, Mark M.; Stanley, Emily H.

    2013-01-01

    Boreal ecosystems store significant quantities of organic carbon (C) that may be vulnerable to degradation as a result of a warming climate. Despite their limited coverage on the landscape, streams play a significant role in the processing, gaseous emission, and downstream export of C, and small streams are thought to be particularly important because of their close connection with the surrounding landscape. However, ecosystem carbon studies do not commonly incorporate the role of the aquatic conduit. We measured carbon dioxide (CO2) and methane (CH4) concentrations and emissions in a headwater stream network of interior Alaska underlain by permafrost to assess the potential role of stream gas emissions in the regional carbon balance. First-order streams exhibited the greatest variability in fluxes of CO2 and CH4,and the greatest mean pCO2. High-resolution time series of stream pCO2 and discharge at two locations on one first-order stream showed opposing pCO2 responses to storm events, indicating the importance of hydrologic flowpaths connecting CO2-rich soils with surface waters. Repeated longitudinal surveys on the stream showed consistent areas of elevated pCO2 and pCH4, indicative of discrete hydrologic flowpaths delivering soil water and groundwater having varying chemistry. Up-scaled basin estimates of stream gas emissions suggest that streams may contribute significantly to catchment-wide CH4 emissions. Overall, our results indicate that while stream-specific gas emission rates are disproportionately high relative to the terrestrial landscape, both stream surface area and catchment normalized emission rates were lower than those documented for the Yukon River Basin as a whole. This may be due to limitations of C sources and/or C transport to surface waters.

  18. Comprehensive multiyear carbon budget of a temperate headwater stream

    NASA Astrophysics Data System (ADS)

    Argerich, Alba; Haggerty, Roy; Johnson, Sherri L.; Wondzell, Steven M.; Dosch, Nicholas; Corson-Rikert, Hayley; Ashkenas, Linda R.; Pennington, Robert; Thomas, Christoph K.

    2016-05-01

    Headwater streams comprise nearly 90% of the total length of perennial channels in global catchments. They mineralize organic carbon entering from terrestrial systems, evade terrestrial carbon dioxide (CO2), and generate and remove carbon through in-stream primary production and respiration. Despite their importance, headwater streams are often neglected in global carbon budgets primarily because of a lack of available data. We measured these processes, in detail, over a 10 year period in a stream draining a 96 ha forested watershed in western Oregon, USA. This stream, which represents only 0.4% of the watershed area, exported 159 kg C ha-1 yr-1, similar to the global exports for large rivers. Stream export was dominated by downstream transport of dissolved inorganic carbon (63 kg C ha-1 yr-1) and by evasion of CO2 to the atmosphere (42 kg C ha-1 yr-1), leaving the remainder of 51 kg C ha-1 yr-1 for downstream transport of organic carbon (17 kg C ha-1 yr-1 and 34 kg C ha-1 yr-1 in dissolved and particulate form, respectively).

  19. Are Salamanders Useful Indicators of Hydrologic Permanence in Headwater Streams?

    NASA Astrophysics Data System (ADS)

    Johnson, B.; Fritz, K.

    2005-05-01

    Regulatory agencies need appropriate indicators of stream permanence to aid in jurisdictional determinations for headwater streams. We evaluated salamanders as permanence indicators because they are often abundant in fishless headwaters. Salamander and habitat data were collected in spring and summer 2003 from 59 sites located longitudinally along 17 forested streams in KY, IN, and OH. Larval Eurycea bislineata/cirrigera dominated all forests, and their abundances were highly correlated with drainage areas and channel dimensions. Appalachian streams were more diverse and had intermittent sites with more Desmognathus and Gyrinophilus spp. Of 22 sites where larvae were collected in spring, 9 sites subsequently dried in summer, suggesting salamanders either emigrated or died. We therefore only used taxa with multi-year larval stages as indicators of perennial water. Salamander larvae >1 yr old were collected from each locality in drainage areas <0.17 km2. However, these older larvae were often found in isolated pools that serve as refugia during dry periods. Findings suggest salamanders with multi-year larval periods can indicate perennial waters and that their use is more effective in Appalachia where abundance and diversity are high. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

  20. From headwaters to coast: Influence of human activities on water quality of the Potomac River Estuary

    USGS Publications Warehouse

    Bricker, Suzanne B.; Rice, Karen C.; Bricker, Owen P.

    2014-01-01

    The natural aging process of Chesapeake Bay and its tributary estuaries has been accelerated by human activities around the shoreline and within the watershed, increasing sediment and nutrient loads delivered to the bay. Riverine nutrients cause algal growth in the bay leading to reductions in light penetration with consequent declines in sea grass growth, smothering of bottom-dwelling organisms, and decreases in bottom-water dissolved oxygen as algal blooms decay. Historically, bay waters were filtered by oysters, but declines in oyster populations from overfishing and disease have led to higher concentrations of fine-sediment particles and phytoplankton in the water column. Assessments of water and biological resource quality in Chesapeake Bay and tributaries, such as the Potomac River, show a continual degraded state. In this paper, we pay tribute to Owen Bricker’s comprehensive, holistic scientific perspective using an approach that examines the connection between watershed and estuary. We evaluated nitrogen inputs from Potomac River headwaters, nutrient-related conditions within the estuary, and considered the use of shellfish aquaculture as an in-the-water nutrient management measure. Data from headwaters, nontidal, and estuarine portions of the Potomac River watershed and estuary were analyzed to examine the contribution from different parts of the watershed to total nitrogen loads to the estuary. An eutrophication model was applied to these data to evaluate eutrophication status and changes since the early 1990s and for comparison to regional and national conditions. A farm-scale aquaculture model was applied and results scaled to the estuary to determine the potential for shellfish (oyster) aquaculture to mediate eutrophication impacts. Results showed that (1) the contribution to nitrogen loads from headwater streams is small (about 2 %) of total inputs to the Potomac River Estuary; (2) eutrophic conditions in the Potomac River Estuary have improved in

  1. Multi-Model CIMP5 projected impacts of increased greenhouse gases on the Niger basin and implications for hydropower production

    NASA Astrophysics Data System (ADS)

    Oyerinde, Ganiyu; Wisser, Dominik

    2014-05-01

    Climate change could potentially have large impacts on water availability in West Africa and the predictions are accrued with high uncertainties in this region. Countries in the Niger River basin (West Africa) plan the investment of 200 million in the installation of an additional 400MW of hydropower in the nearest future, adding to the existing 685MW. With the impacts of climate change in the basin already occurring, there is a need for comprehending the influence of future hydro-climatic changes on water resources and hydro-power generation in the basin. This study uses a hydrological model to simulate river flow under present and future conditions and evaluates the impacts of potential changes on electricity production of the largest hydroelectric dam (Kainji) in the Niger Basin. The Kainji reservoir produces 25 per cent of the current energy needs of Nigeria and was subject to large fluctuations in energy production as a result of variable inflow and operational reasons. Inflow into the reservoir was simulated using hydroclimatic data from a set of 7 regional climate models (RCM) with two emission scenarios from the CORDEX-Africa regional downscaling experiment, driven with CMIP5 data. Based on observations of inflow, water level in the reservoir, and energy production we developed a simple hydroelectricity production model to simulate future energy production for the reservoir. Results suggest increases in river flow for the majority of RCM data as a result of increases in precipitation in the headwaters of the basin around 2050 and slightly decreasing trends for low emission scenarios by the end of the century. Despite this consistent increase, shifts in timing of river flow can challenge the reliable production of energy. This analysis could help assess the planning of hydropower schemes in the basin for a sustainable production of hydroelectricity in the future.

  2. Pattern and process in Northern Rocky Mountain headwaters: Ecological linkages in the headwaters of the Crown of the Continent

    SciTech Connect

    Hauer, F.R.; Stanford, J.A.; Lorang, M.S.

    2007-02-15

    The Crown of the Continent is one of the premiere ecosystems in North America containing Waterton-Glacier International Peace Park, the Bob Marshall-Great Bear-Scapegoat Wilderness Complex in Montana, various Provincial Parks in British Columbia and Alberta, several national and state forest lands in the USA, and Crown Lands in Canada. The region is also the headwater source for three of the continent's great rivers: Columbia, Missouri and Saskatchewan that flow to the Pacific, Atlantic and Arctic Oceans, respectively. While the region has many remarkably pristine headwater streams and receiving rivers, there are many pending threats to water quality and quantity. One of the most urgent threats comes from the coal and gas fields in the northern part of the Crown of the Continent, where coal deposits are proposed for mountain-top removal and open-pit mining operations. This will have significant effects on the waters of the region, its native plants and animals and quality of life of the people.

  3. Predicting alpine headwater stream intermittency: a case study in the northern Rocky Mountains

    USGS Publications Warehouse

    Sando, Thomas R.; Blasch, Kyle W.

    2015-01-01

    This investigation used climatic, geological, and environmental data coupled with observational stream intermittency data to predict alpine headwater stream intermittency. Prediction was made using a random forest classification model. Results showed that the most important variables in the prediction model were snowpack persistence, represented by average snow extent from March through July, mean annual mean monthly minimum temperature, and surface geology types. For stream catchments with intermittent headwater streams, snowpack, on average, persisted until early June, whereas for stream catchments with perennial headwater streams, snowpack, on average, persisted until early July. Additionally, on average, stream catchments with intermittent headwater streams were about 0.7 °C warmer than stream catchments with perennial headwater streams. Finally, headwater stream catchments primarily underlain by coarse, permeable sediment are significantly more likely to have intermittent headwater streams than those primarily underlain by impermeable bedrock. Comparison of the predicted streamflow classification with observed stream status indicated a four percent classification error for first-order streams and a 21 percent classification error for all stream orders in the study area.

  4. Large wood dynamics in central Appalachian hemlock headwater ravines

    NASA Astrophysics Data System (ADS)

    Costigan, K. H.; Soltesz, P.; Jaeger, K. L.

    2014-12-01

    Large wood (LW) is a critical component to forested mountain headwater streams contributing significantly to geomorphic and ecological processes. The character of LW is a function of valley recruitment processes that influence LW entering the channel and instream retention processes that influence LW transport through the channel reach. In the central Appalachian Mountains, US, LW dynamics in eastern hemlock-dominated ravines may change due to the invasive insect Hemlock Wooly Adelgid (HWA). However, quantitative LW studies are lacking for this region, which are necessary for effective management of projected HWA-associated change. We examined LW dynamics across central Appalachian headwater streams to identify 1) the current state of LW load, 2) the relative environmental factors that influence LW load, 3) potential signs of HWA impact on LW dynamics, and 4) functional grouping patterns of LW pieces in these systems. In a field study that included 24 sites in Ohio, West Virginia, and Virginia, mean wood density was 36 pieces/100m ± 21 and mean wood volume was 5.6 m3/100m ± 3.5. Most pieces were less than bankfull width suggesting high transportability, but large pieces (>10m) contributed significantly to wood volume, jam formation, and geomorphic function. Central Appalachian LW load was on the lower end of mountain headwater streams, but comparable to the northeastern US. A mixture of recruitment and retention processes influence wood dynamics, but channel retention processes better explain jam dynamics. Specifically, higher wood load was associated with lower forest basal area, smaller channel dimensions, and lower hydraulic driving forces, which is consistent with other studies. We did not detect a significant influence on wood load as a result of HWA infestation of ~20 years, which may reflect a lag period between tree mortality, toppling, and LW load. Pieces clustered in three functional groups of 1) larger, stable pieces that store sediment, stabilize the

  5. Elements of an environmental decision support system for seasonal wetland salt management in a river basin subjected to water quality regulation

    SciTech Connect

    Quinn, N.W.T.

    2009-06-01

    Seasonally managed wetlands in the Grasslands Basin on the west-side of California's San Joaquin Valley provide food and shelter for migratory wildfowl during winter months and sport for waterfowl hunters during the annual duck season. Surface water supply to these wetlands contain salt which, when drained to the San Joaquin River during the annual drawdown period, can negatively impact water quality and cause concern to downstream agricultural riparian water diverters. Recent environmental regulation, limiting discharges salinity to the San Joaquin River and primarily targeting agricultural non-point sources, now also targets return flows from seasonally managed wetlands. Real-time water quality management has been advocated as a means of continuously matching salt loads discharged from agricultural, wetland and municipal operations to the assimilative capacity of the San Joaquin River. Past attempts to build environmental monitoring and decision support systems (EDSS's) to implement this concept have enjoyed limited success for reasons that are discussed in this paper. These reasons are discussed in the context of more general challenges facing the successful implementation of a comprehensive environmental monitoring, modelling and decision support system for the San Joaquin River Basin.

  6. Controls on scaling relationships of dynamic headwater stream networks

    NASA Astrophysics Data System (ADS)

    Godsey, S.; Kirchner, J. W.; Whiting, J. A.

    2013-12-01

    Stream networks expand and contract within their channel network, particularly within their headwaters. Along their length, especially during drought periods, it is not unusual to encounter dry reaches of varying lengths. Controls on the length and location of those dry reaches include: large woody debris, upstream sediment loading, hydraulic properties of the subsurface/hyporheic zone, and the catchment hydroclimate and morphology. Here we examine patterns in the length of discontinuous reaches, their location, and the length of the overall drainage network. We find that drainage networks expand with discharge as a power-law relationship with a slope of ~0.25, contradicting recent theoretical suggestions in the literature that this scaling exponent should be close to 1.0. We discuss physical limitations on the range of potential scaling relationships, and link stream responses to groundwater and evapotranspiration sources and sinks.

  7. Shallow bedrock limits groundwater seepage-based headwater climate refugia

    USGS Publications Warehouse

    Briggs, Martin; Lane, John; Snyder, Craig D.; White, Eric A.; Johnson, Zachary; Nelms, David L.; Hitt, Nathaniel P.

    2017-01-01

    Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive to seasonal and long-term air temperature dynamics. Depth to bedrock can directly influence shallow aquifer flow and thermal sensitivity, but is typically ill-defined along the stream corridor in steep mountain catchments. We employ rapid, cost-effective passive seismic measurements to evaluate the variable thickness of the shallow colluvial and alluvial aquifer sediments along a headwater stream supporting cold water-dependent brook trout (Salvelinus fontinalis) in Shenandoah National Park, VA, USA. Using a mean depth to bedrock of 2.6 m, numerical models predicted strong sensitivity of shallow aquifer temperature to the downward propagation of surface heat. The annual temperature dynamics (annual signal amplitude attenuation and phase shift) of potential seepage sourced from the shallow modeled aquifer were compared to several years of paired observed stream and air temperature records. Annual stream water temperature patterns were found to lag local air temperature by ∼8–19 d along the stream corridor, indicating that thermal exchange between the stream and shallow groundwater is spatially variable. Locations with greater annual signal phase lag were also associated with locally increased amplitude attenuation, further suggestion of year-round buffering of channel water temperature by groundwater seepage. Numerical models of shallow groundwater temperature that incorporate regional expected climate warming trends indicate that the summer cooling capacity of this groundwater seepage will be reduced over time, and lower-elevation stream sections may no longer serve as larger

  8. Turbidity dynamics during spring storm events in an urban headwater river system: the Upper Tame, West Midlands, UK.

    PubMed

    Lawler, D M; Petts, G E; Foster, I D L; Harper, S

    2006-05-01

    Turbidity is an important water quality variable, through its relation to light suppression, BOD impact, sediment-associated contaminant transport, and suspended sediment effects on organisms and habitats. Yet few published field investigations of wet-weather turbidity dynamics, through several individual and sequenced rainstorms in extremely urbanised headwater basins, have emerged. This paper aims to address this gap through a turbidity analysis of multiple storm events in spring 2001 in an urban headwater basin (57 km2) of the River Tame, central England, the most urbanised basin for its size in the UK ( approximately 42%). Data were collected at 15-min frequency at automated monitoring stations for rainfall, streamflow and six water quality variables (turbidity, EC, temperature, DO, pH, ammonia). Disturbance experiments also allowed estimates of bed sediment storage to be obtained. Six important and unusual features of the storm event turbidity response were apparent: (1) sluggish early turbidity response, followed by a turbidity 'rush'; (2) quasi-coincident flow and turbidity peaks; (3) anti-clockwise hysteresis in the discharge-turbidity relationship on all but one event, resulting from Falling-LImb Turbidity Extensions (FLITEs); (4) increases in peak turbidity levels through storm sequences; (5) initial micro-pulses (IMP) in turbidity; and (6) secondary turbidity peaks (STP) or 'turbidity shoulders' (TS). These features provided very little evidence of a true 'first-flush' effect: instead, substantial suspended solids transport continued right through the flow recessions, and little storm-event sediment exhaustion was evident. A new, dimensionless, hysteresis index, HI(mid), is developed to quantify the magnitude and direction of hysteresis in a simple, clear, direct and intuitive manner. This allowed the degree of departure from the classic 'first-flush', clockwise hysteresis models to be assessed. Of the 15 turbidity events considered, 10 coincided with

  9. Geologic, biogeomorphic, and hydrologic controls on floodplain organic carbon retention in mountainous headwater streams of the Colorado Front Range, USA

    NASA Astrophysics Data System (ADS)

    Sutfin, N. A.; Wohl, E.

    2014-12-01

    Unaltered mountainous streams provide insight into natural processes and mechanisms of organic carbon (OC) retention in riparian ecosystems. Our prior work indicates that downed large wood and soil OC are the primary reservoirs for OC storage in mountainous headwaters streams of the Colorado Front Range. We surveyed downed large wood and floodplain soil along 24 study reaches in mountainous headwater streams in and around Rocky Mountain National Park, CO. Comparison of study reaches with various degrees of valley confinement in old growth (>200 yrs) and younger subalpine and montane forests reveals geologic and biogeomorphic controls for OC retention. Preliminary results indicate that unconfined valley segments store much more OC per area (783 Mg/ha) compared to partly confined and confined valley segments (153 Mg/ha). Unconfined valley segments store a significant amount of OC along single thread channels and facilitate potential for development of multithread channels. Multithread channels in old-growth forests, with trees large enough to create persistent channel-spanning logjams, store relatively little sediment and a disproportionately large amount of OC as large wood. Beaver dams also facilitate the development of multithread channels and high soil OC content in beaver meadows constitutes the largest OC pools among all channel types. Preliminary reach-average radiocarbon ages from charcoal in floodplain sediment of three study reaches with drainage areas <20 km2 (1438 ± 84 yBP), 20 - 100 km2 (539 ± 110 yBP), and >100 km2 (887 ± 84 yBP) indicate that floodplain sediment turnover time is much longer in small streams at higher, subalpine elevations. Snowmelt-dominated hydrographs in these high-elevation streams rarely exhibit bimodal characteristics typical of the hydrologic disturbance regime in lower elevation montane forests of the region, which are influenced by large convective thunderstorms and monsoons of the southwestern US. The downstream cumulative

  10. Water quality in the Tibetan Plateau: major ions and trace elements in the headwaters of four major Asian rivers.

    PubMed

    Huang, Xiang; Sillanpää, Mika; Gjessing, Egil T; Vogt, Rolf D

    2009-12-01

    The Tibetan Plateau covers an area of about one fourth of Europe, has an average elevation over 4000m above sea level, and is the water sources for about 40% of world's population. In order to foresee future changes in water quality, it is important to understand what pressures are governing the spatial variation in water chemistry. In this paper the chemistry including major ions and trace elements in the headwaters of four major Asian rivers (i.e. the Salween, Mekong, Yangtze River and Yarlung Tsangpo) in the Tibetan Plateau was studied. The results showed that the content of dissolved salts in these Tibetan rivers was relatively high compared to waters from other parts of the world. The chemical composition of the four rivers were rather similar, with Ca(2+) and HCO(3)(-) being the dominating ions. The exception was the Yangtze River on the Plateau, which was enriched in Na(+), Cl(-), SO(4)(2-) and Li due to silicate weathering followed by strong evaporation caused by a negative water balance, dissolution of evaporites in the catchment and some drainage from saline lakes. The concentrations of heavy metals (Cu, Co, Cr, Ni, Cd, Pb, and Hg) and As, NH(4)(+) were generally low in all the rivers. Anthropogenic impacts on the quality of the rivers were identified at a few locations in the Mekong River and Yarlung Tsangpo basins. Generally, the main spatial variation in chemical compositions of these under studied rivers was found to be governed mainly by difference in geological variation and regional climatic-environment. Climate change is, therefore, one of main determining factors on the water chemical characteristics of these headwaters of Asian major rivers in the Tibetan Plateau.

  11. Restoring the hydrologic response to pre-developed conditions in an urbanized headwater catchment: Reality or utopia?

    NASA Astrophysics Data System (ADS)

    Wright, O.; Istanbulluoglu, E.

    2012-12-01

    The conversion of forested areas to impervious surfaces, lawns and pastures alters the natural hydrology of an area by increasing the flashiness of stormwater generated runoff, resulting in increased streamflow peaks and volumes. Currently, most of the stormwater from developed areas in the Puget Sound region remains uncontrolled. The lack of adequate stormwater facilities along with increasing urbanization and population growth illustrates the importance of understanding urban watershed behavior and best management practices (BMPs) that improve changes in hydrology. In this study, we developed a lumped urban ecohydrology model that represents vegetation dynamics, connects pervious and impervious surfaces and implements various BMP scenarios. The model is implemented in an urban headwater subcatchment located in the Newaukum Creek Basin. We evaluate the hydrologic impact of controlling runoff at the source and disconnecting impervious surfaces from the storm drain using rain barrels and bioretention cells. BMP scenarios consider the basin's land use/land coverage, the response of different impervious surface types, the potential for BMP placement, the size and drainage area for BMPs, and the mitigation needs to meet in-stream flow goals.

  12. Factors influencing water transit times in snowmelt-dominated, headwater catchments of the western U.S.

    NASA Astrophysics Data System (ADS)

    Clow, D. W.; Mast, A.

    2015-12-01

    In catchments, water transit times (TTs) refer to the elapsed time between entry of water at the ground surface and exit of water at the catchment outlet. Transit times are an important characteristic of catchments in that they reflect the time available for interaction between water, soil, and biota within the system. Thus, they exert a strong influence on hydrologic resilience to drought and climate change, and on the sensitivity of aquatic ecosystems to atmospheric pollutants. Transit times may vary spatially due to variations in basin characteristics, such as slope, size, and amount and type of soil and vegetation; however, the relative influence of these factors on TTs is poorly known. In this study, we estimate mean transit times (MTTs) for 11 snowmelt-dominated, headwater catchments in the western U.S. using the convolution integral approach, which relies on differences in the magnitude of seasonal variability in δ18O in precipitation and stream water to estimate MTTs. Seasonal variability in δ18O was calculated based on analyses of precipitation and stream water samples collected at weekly to monthly intervals. Results indicate that MTTs ranged from 0.6 to 2.1 years, and were positively influenced by percent of the catchment covered by forest (r2 = 0.56; p = 0.008), and negatively influenced by barren terrain (e.g., bedrock; r2 = 0.48; p = 0.019). MTTs showed a weak negative relation to mean basin slope (r2 = 0.31; p = 0.076) and no relation to basin size or elevation. These results illustrate the importance of soil as a key factor influencing MTTs, with basin slope acting as a secondary influence. Heavily forested basins tend to have deep, well-developed soils with substantial water storage capacity; these soils help maintain baseflow during drought conditions, providing hydrologic resilience to the system, and they are an important location for geochemical and biological processes that neutralize acidity and assimilate atmospherically deposited nitrogen

  13. Macroinvertebrate and organic matter export from headwater tributaries of a Central Appalachian stream

    EPA Science Inventory

    Headwater streams export organisms and other materials to their receiving streams and macroinvertebrate drift can shape colonization dynamics in downstream reaches while providing food for downstream consumers. Spring-time macroinvertebrate drift and organic matter export was me...

  14. South Platte Watershed from the Headwaters to the Denver Metropolitan Area (Colorado) Systems Thinking

    EPA Pesticide Factsheets

    South Platte Watershed from the Headwaters to the Denver Metropolitan Area (Colorado) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating

  15. A synoptic survey of ecosystem services from headwater catchments in the United States (presentation)

    EPA Science Inventory

    Ecosystem production functions for water supply, climate regulation, and water purification were estimated for 568 headwater streams and their catchments. Water supply per unit catchment area was highest in the Northern Appalachian Mountains and lowest in the Northern Plains. C, ...

  16. A synoptic survey of ecosystem services from headwater catchments in the United States- webinar

    EPA Science Inventory

    Ecosystem production functions for water supply, climate regulation, and water purification were estimated for 568 headwater streams and their catchments. Water supply per unit catchment area was highest in the Northern Appalachian Mountains and lowest in the Northern Plains. C, ...

  17. Larval salamanders and channel geomorphology are indicators of hydrologic permanence in forested headwater streams

    EPA Science Inventory

    Regulatory agencies need rapid indicators of hydrologic permanence for jurisdictional determinations of headwater streams. Our study objective was to assess the utility of larval salamander presence and assemblage structure and habitat variables for determining stream permanence ...

  18. Use of spatially explicit physicochemical data to measure downstream impacts of headwater stream disturbance

    EPA Science Inventory

    Regulatory agencies need methods to quantify the influence of headwater streams on downstream water quality as a result of litigation surrounding jurisdictional criteria and the influence of mountaintop removal coal mining activities. We collected comprehensive, spatially-referen...

  19. Urbanization Affects the Extent and Hydrologic Permanence of Headwater Streams in a Midwestern US Metropolitan Area

    EPA Science Inventory

    Headwater streams dominate natural landscapes and provide essential functions for downstream waters. However, because of minimal legal protection, they often are piped or buried to accommodate urban growth. Urbanization also alters stream base flows. The combined impact of these ...

  20. Influence of instream habitat and water chemistry on amphibians within channelized agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The widespread use of stream channelization and subsurface tile drainage for draining agricultural fields has led to the development of numerous channelized agricultural headwater streams within agricultural watersheds of the Midwestern United States, Canada, and Europe. Channelized agricultural he...

  1. Characterization and classification of invertebrates as indicators of flow permanence in headwater streams

    EPA Science Inventory

    Headwater streams represent a large proportion of river networks and many have temporary flow. Litigation has questioned whether these streams are jurisdictional under the Clean Water Act. Our goal was to identify indicators of flow permanence by comparing invertebrate assemblage...

  2. Can bryophytes be used to characterize hydrologic permanence in forested headwater streams?

    EPA Science Inventory

    Recent court cases have questioned whether all headwater streams, particularly those that are not perennial, fall within the protective boundaries of the Clean Water Act. Rapid field-based indicators of hydrologic permanence are critically needed for jurisdictional determination...

  3. Importance of environmental factors on the richness and distribution of benthic macroinvertebrates in tropical headwater streams

    EPA Science Inventory

    It is essential to understand the interactions between local environmental factors (e.g., physical habitat and water quality) and aquatic assemblages to conserve biodiversity in tropical and subtropical headwater streams. Therefore, we evaluated the relative importance of multipl...

  4. 77 FR 2754 - Establishment of Everglades Headwaters National Wildlife Refuge and Conservation Area

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-19

    ... in central and south Florida, helping to protect and restore one of the great grassland and savanna... of and support for conservation of the important grassland and savanna landscape of the headwaters...

  5. Differences in instream wood characteristics between channelized and unchannelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Instream wood is an important resource for stream biota because it provides cover for fishes, substrate for macroinvertebrates, and increases habitat diversity. However, current management of instream wood within channelized agricultural headwater streams (drainage ditches) involves removing instrea...

  6. IMPACTS OF LAND USE ON HYDROLOGIC FLOW PERMANENCE IN HEADWATER STREAMS

    EPA Science Inventory

    Extensive urbanization in the watershed can alter the stream hydrology by increasing peak runoff frequency and reducing base flows, causing subsequent impairment of stream community structure. In addition, development effectively eliminates some headwater streams, being piped an...

  7. The importance of instream habitat modifications for restoring channelized agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Science based information on the influence of restoration practices on fishes within channelized agricultural headwater streams in the Midwestern United States is currently lacking. Understanding fish-habitat relationships and fish responses to specific restoration practices will provide informatio...

  8. Spawning characteristics of redband trout in a headwater stream in Montana

    USGS Publications Warehouse

    Muhlfeld, Clint C.

    2002-01-01

    I investigated the spawning characteristics of redband trout Oncorhynchus mykiss gairdneri (a rainbow trout subspecies) during the spring of 1998 in Basin Creek, a third-order headwater stream located in the Kootenai River drainage in northwestern Montana. I examined the timing of spawning as related to discharge and water temperature and analyzed microhabitat selection of 30 completed redds in a low-gradient (0.5–1.5%) reach. Redband trout spawned as flow declined after peak runoff and as mean daily water temperature exceeded 6.0C and maximum daily temperature exceeded 7.0C. Redband trout began spawning on 6 June (mean daily discharge = 2.1 m3/s), 10 d after the peak discharge (8.7 m3/s) occurred. The last redd was completed on 24 June, when discharge was 1.5 m3/s. The mean total redd length was 53 cm (SD = 14; range = 31–91 cm), and the mean total area was 51 cm2 (SD = 8; range= 46– 76 cm2). Eighty percent of the redds were located in pool tailouts, 13% in runs, and 7% in riffles. Spawning redband trout selected redd sites based on substrate size and water depth but not water velocity. Fish selected substrate sizes of 2–6 mm, water depths of 20–30 cm, and water velocities of 40–70 cm/s. My results suggest that redband trout in a low-gradient, third-order mountain stream found suitable spawning habitat in pool tail-outs that contained abundant gravels.

  9. Glacier contribution to streamflow in two headwaters of the Huasco River, Dry Andes of Chile

    NASA Astrophysics Data System (ADS)

    Gascoin, S.; Kinnard, C.; Ponce, R.; Lhermitte, S.; MacDonell, S.; Rabatel, A.

    2011-12-01

    Quantitative assessment of glacier contribution to present-day streamflow is a prerequisite to the anticipation of climate change impact on water resources in the Dry Andes. In this paper we focus on two glaciated headwater catchments of the Huasco Basin (Chile, 29° S). The combination of glacier monitoring data for five glaciers (Toro 1, Toro 2, Esperanza, Guanaco, Estrecho and Ortigas) with five automatic streamflow records at sites with glacier coverage of 0.4 to 11 % allows the estimation of the mean annual glacier contribution to discharge between 2003/2004 and 2007/2008 hydrological years. In addition, direct manual measurements of glacier runoff were conducted in summer at the snouts of four glaciers, which provide the instantaneous contribution of glacier meltwater to stream runoff during summer. The results show that the mean annual glacier contribution to streamflow ranges between 3.3 and 23 %, which is greater than the glaciated fraction of the catchments. We argue that glacier contribution is partly enhanced by the effect of snowdrift from the non-glacier area to the glacier surface. Glacier mass loss is evident over the study period, with a mean of -0.84 m w.e. yr-1 for the period 2003/2004-2007/2008, and also contributes to increase glacier runoff. An El Niño episode in 2002 resulted in high snow accumulation, modifying the hydrological regime and probably reducing the glacier contribution in favor of seasonal snowmelt during the subsequent 2002/2003 hydrological year. At the hourly timescale, summertime glacier contributions are highly variable in space and time, revealing large differences in effective melting rates between glaciers and glacierets (from 1 mm w.e. h-1 to 6 mm w.e. h-1).

  10. Biological assessment to support ecological recovery of a degraded headwater system.

    PubMed

    Longing, Scott D; Haggard, Brian E

    2010-09-01

    An assessment of the benthic macroinvertebrate community was conducted to characterize the ecological recovery of a channelized main stem and two small tributaries at the Watershed Research and Education Center (WREC, Arkansas, USA). Three other headwater streams in the same basin were also sampled as controls and for biological reference information. A principal components analysis produced stream groupings along an overall gradient of physical habitat integrity, with degraded reaches showing lower RBP habitat scores, reduced flow velocities, smaller substrate sizes, greater conductivity, and higher percentages of sand and silt substrate. The benthic macroinvertebrate assemblage at WREC was dominated by fast-reproducing dipteran larvae (midge and mosquito larvae) and physid snails, which comprised 71.3% of the total macroinvertebrate abundance over three sampling periods. Several macroinvertebrate assemblage metrics should provide effective targets for monitoring overall improvements in the invertebrate assemblage including recovery towards a more complex food web (e.g., total number of taxa, number of EPT taxa, percent 2 dominant taxa). However, current habitat conditions and the extent of existing degradation, system isolation and surrounding urban or agricultural land-uses might affect the level of positive change to the system. We therefore suggest a preliminary restoration strategy involving the addition of pool habitats in the system. At one pool we collected a total of 29 taxa (dominated by water beetle predators), which was 59% of total number of taxa collected at WREC. Maintaining water-retentive pools to collect flows and maintain water permanence focuses on enhancing known biology and habitat, thus reducing the effects of abiotic filters on macroinvertebrate assemblage recovery. Furthermore, biological assessment prior to restoration supports a strategy primarily focused on improving the existing macroinvertebrate community in the current context of the

  11. Linking Soil Moisture, Micro-climate, and Transpiration in a Headwater Catchment

    NASA Astrophysics Data System (ADS)

    Barnard, H. R.; Brooks, J.; Kayler, Z.; Sulzman, E. W.; Phillips, C. L.; McDonnell, J. J.; Bond, B. J.

    2007-12-01

    Evapotranspiration is a major determinant of streamflow in forested basins. However, the role topography plays in forest water relations is poorly understood. To date, many hydrological models use only a single value for transpiration across a catchment. Quantifying the variation in forest water use with regards to slope position is central to understanding controls on water quantity and quality in hydro-ecological models and is critical to predicting the hydrologic impacts of various forestry operations. We measured transpiration, soil moisture, and foliar pre-dawn water potential in 4 plots across a ridge to ridge transect throughout the summers of 2005 and 2006 in a headwater catchment in western Oregon. Additionally, we measured deuterium and 18O of xylem water and soil water to track changes in the depth of transpiration source water throughout the summers. From May through October 2006, daily average transpiration in upslope plots was approximately 40% greater than that of valley bottom plots (1.0 mm day-1 vs. 0.6 mm day-1, respectively). Minimum pre-dawn water potential values ranged from -0.8 to -1.3 MPA in late August with north-facing plots having the lowest values. Stable isotope data indicates that transpiration rates remained higher longer in the growing season in plots where trees were able to access water deeper in the soil profile. Preliminary data suggest that topographic gradients influencing soil depth, soil moisture retention, and micro-climate result in large variation in forest water use over very small distances.

  12. Forest management effects on snow, runoff and evapotranspiration in Sierra Nevada mixed-conifer headwater catchments

    NASA Astrophysics Data System (ADS)

    Ray, R. L.; Saksa, P. C.; Bales, R. C.; Conklin, M. H.

    2012-12-01

    We used intensive field measurements and data-intensive hydro-ecological modeling to investigate the impact of forest vegetation management on the sensitivity of snow accumulation, evapotranspiration and discharge at seven headwater catchments in the Sierra Nevada. Catchments are located in dense mixed-conifer forest, at elevations of 1500 - 2100 m, and receive a mix of rain and snow precipitation. Management scenarios for reducing forest density by uniform thinning and forest clearings were implemented in the Regional Hydro-ecological Simulation System (RHESSys). Results obtained using inherent model equations to separate total precipitation into snow and rain underestimated snow water content in some of the catchments, requiring manual input of snow and rain for accurate simulations. Modeling precipitation phase accurately was critical for the current forest condition, as the change in vegetation has differing effects on rain, snow and snowmelt. Results using RHESSys show that light, uniform thinning alone (<20% canopy) may not be enough to change water yield significantly, but this threshold of canopy reduction is lowered by creating gaps in the forest alone or in combination with uniform thinning, and has potential to measurably increase water yield beyond background variation. Clarifying these specific impacts of forest vegetation on snow processes and water yield is essential for simulating forest management in the Sierra Nevada and it shows the forest structure has significant influence on the catchment water balance. However, modifying forest canopy density and canopy cover to calculate average levels of snow water equivalent at a basin-scale may not be detailed enough to incorporate all the complex forest structure effects on snow processes in mountain watersheds.

  13. Influence of forest management on headwater stream amphibians at multiple spatial scales

    USGS Publications Warehouse

    Stoddard, Margo; Hayes, John P.; Erickson, Janet L.

    2004-01-01

    Background Amphibians are important components of headwater streams in forest ecosystems of the Pacific Northwest (PNW). They comprise the highest vertebrate biomass and density in these systems and are integral to trophic dynamics both as prey and as predators. The most commonly encountered amphibians in PNW headwater streams include the Pacific giant salamander (Dicamptodon tenebrosus), the tailed frog (Ascaphus truei), the southern torrent salamander (Rhyacotriton variegatus), and the Columbia torrent salamander (R. kezeri).

  14. Export, biodegradation, and disinfection byproduct formation of dissolved and particulate organic carbon in a forested headwater stream during extreme rainfall events

    NASA Astrophysics Data System (ADS)

    Jung, B.-J.; Lee, J.-K.; Kim, H.; Park, J.-H.

    2014-11-01

    Despite an increasing recognition of the importance of extreme rainfall events for organic carbon export to inland waters, little attention has been paid to the export and reactivity of particulate organic carbon (POC) and dissolved organic C (DOC) in mountainous headwater watersheds under monsoon climates. To investigate environmental implications of storm-enhanced export of POC and DOC in mountainous headwater streams, we examined the relationships between storm magnitude and C export from a forested watershed in the Haean Basin, South Korea, during 13 storm events over 4 years and compared potentials of DOC and POC for biodegradation and disinfection byproduct (DBP) formation during an extreme rainfall event with a total rainfall of 209 mm. Event mean concentrations and export of POC increased nonlinearly above thresholds of precipitation and discharge, far exceeding the relatively small increases of DOC. The export of POC during a few storm events with a total rainfall above 200 mm per event exceeded the annual organic C export during dry years. During the 209 mm storm event, concentrations of total trihalomethanes formed by POC-derived dissolved components changed synchronously with POC concentrations, exhibiting lower levels than those formed by DOC. During a 30-day incubation at 25 °C, DOC exported during peak flow exhibited rapid biodegradation of labile components within 7 days. In contrast, the concentrations of DOC leached from POC gradually increased following the initial decline. Gradual transformation of POC-derived dissolved materials resulted in greater increases in the intensity of fulvic- and humic-like fluorescent components compared to the DOC treatment. The results highlight the significance of extreme rainfall events as "hot moments" for POC export from mountainous watersheds and also suggest that storm pulses of POC can provide potential sources of reactive organic components that can rapidly biodegrade and form DBPs after being released

  15. Storm pulses of particulate and dissolved organic carbon in a forested headwater stream and their environmental implications - importance of extreme rainfall events

    NASA Astrophysics Data System (ADS)

    Jung, B.-J.; Lee, J.-K.; Kim, H.; Park, J.-H.

    2014-05-01

    Despite recent debates on erosion-enhanced sinks of CO2 and contrasting findings on the biodegradation of recalcitrant organic materials in large rivers, little attention has been paid to the export and transformations of particulate organic carbon (POC) and dissolved organic C (DOC) in mountainous headwater watersheds under monsoon climates. To comparatively evaluate the significance of heavy monsoon rainfalls for the magnitude and environmental implications of storm-enhanced export of POC and DOC, the relationships between storm magnitude and C export were examined in a mountainous, forested headwater stream in the Haean Basin, South Korea, during 50 storm events over the 4 year monitoring period. We also compared biodegradation and disinfection byproduct (DBP) formation potentials of the DOC and POC exported during an extreme rainfall event. Event mean concentrations and export of POC increased nonlinearly above thresholds of precipitation and discharge, significantly exceeding the increases of DOC. The export of POC during a few storm events with a total rainfall above 200 mm per event exceeded the annual organic C export during dry years. During the large storm event (209 mm), concentrations of total trihalomethanes formed by POC-derived dissolved components changed synchronously with POC concentrations, exhibiting lower levels than those formed by DOC. During a 30 day incubation at 25 °C, both DOC and POC exported during peak flow initially exhibited rapid biodegradation of labile components, whereas POC-derived materials increased continuously not only DOC concentrations, but also fulvic- and humic-like fluorescent components. These results highlight the significance of extreme rainfall events as "hot moments" for POC export and also suggest that storm pulses of POC can provide potential sources of labile DOC components that can rapidly biodegrade and form DBPs in headwater streams, contrasting with other studies assuming mountainous rivers as a passive

  16. Guiding soil conservation strategy in headwater mediterranean catchments

    NASA Astrophysics Data System (ADS)

    Ben Slimane, Abir; Raclot, Damien; Evrard, Olivier; Sanaa, Mustapha; Lefèvre, Irène; Le Bissonnais, Yves

    2016-04-01

    Reservoir siltation due to water erosion is an important environmental issue in Mediterranean countries where storage of clear surface water is crucial for their economic and agricultural development. In order to reduce water erosion, this study aimed to design a methodology for guiding the implementation of efficient conservation strategies by identifying the dominant sediment sources in Mediterranean context. To this end, a fingerprinting method was combined with long-term field monitoring of catchment sediment yield in five headwater catchments (0.1-10 km2) equipped with a small reservoir between 1990 and 1995. The five catchments were chosen to cover the large diversity of environmental conditions found along the Tunisian Ridge and in the Cape Bon region. The fingerprinting techniques based on measurements of cesium-137 and Total Organic Carbon within the catchments and in reservoir sediment deposits successfully identified the contribution of rill/interrill and gully/channel erosion to sediment yield at the outlet of five small headwater catchments during the last 15-20 years. Results showed the very large variability of erosion processes among the selected catchments, with rill/interrill erosion contributions to sediment accumulated in outlet reservoirs ranging from 20 to 80%. Overall, rill/interrill erosion was the dominant process controlling reservoir siltation in three catchments whereas gully/channel erosion dominated in the other two catchments. This demonstrates that the dominant erosion process in the Mediterranean regions highly depends on the local environmental context. The lowest rill/interrill erosion contribution (2.2 Mg ha-1 yr-1) in the five catchments remained significantly higher than the tolerable soil loss indicating the severe levels reached by soil erosion along the Tunisian Ridge and in the Cape Bon region. This study also showed that although the implementation of improved topsoil management measures greatly reduced rill

  17. Seasonal Sources of Carbon Exports in a Headwater Stream

    NASA Astrophysics Data System (ADS)

    Argerich, A.; Johnson, S. L.

    2013-12-01

    Climate change is intimately tied to changes in carbon (C) budgets. Understanding the compartments and processes involved in the global C cycle across a landscape is essential to predict future climate change scenarios. While most C budgets focus on terrestrial contributions, river systems contribute to the C cycle by the export of total organic carbon (TOC) and dissolved inorganic carbon (DIC) to the ocean and by exporting CO2 to the atmosphere. Although headwater streams constitute between 60 and 80 percent of fluvial systems their role in the C cycle has often been neglected due to the methodological constrains derived from their heterogeneous morphology. Here we present an analysis of the temporal variation of C export both downstream and evaded to the atmosphere for a headwater stream draining a forested watershed. We relate it to in-stream metabolic processes (respiration and primary production) and to different carbon pools. Specifically, we estimate downstream exports of C in the form of dissolved organic (DOC), dissolved inorganic (DIC), and particulate organic (POC); we estimate the C content in the fine benthic organic matter (FBOM), dead wood, algae, and macroinvertebrate pools; and finally, the amount of CO2 originated and fixed by stream respiration and primary production. Organic exports, both particulate and dissolved, represented 39.7% of the annual downstream export of C while dissolved inorganic C represented 60.3%. Higher exports were observed during periods of high flow (late fall and winter). Highest seasonality in downstream exports was observed for POC (89.5% coefficient of variation in mean monthly fluxes), followed by DOC and DIC (24.3% and 15.9% respectively). Dissolved CO2 had mostly an autochthonous origin during summer (i.e. from stream ecosystem respiration) and originated from allochthonous sources during the rain-dominated months in Oregon (late fall and winter). The stream was net heterotrophic and the amount of C cycled through

  18. A High Resolution, Integrated Approach to Modeling Climate Change Impacts to a Mountain Headwaters Catchment using ParFlow

    NASA Astrophysics Data System (ADS)

    Pribulick, C. E.; Maxwell, R. M.; Williams, K. H.; Carroll, R. W. H.

    2014-12-01

    Prediction of environmental response to global climate change is paramount for regions that rely upon snowpack for their dominant water supply. Temperature increases are anticipated to be greater at higher elevations perturbing hydrologic systems that provide water to millions of downstream users. In this study, the relationships between large-scale climatic change and the corresponding small-scale hydrologic processes of mountainous terrain are investigated in the East River headwaters catchment near Gothic, CO. This catchment is emblematic of many others within the upper Colorado River Basin and covers an area of 250 square kilometers, has a topographic relief of 1420 meters, an average elevation of 3266 meters and has varying stream characteristics. This site allows for the examination of the varying effect of climate-induced changes on the hydrologic response of three different characteristic components of the catchment: a steep high-energy mountain system, a medium-grade lower-energy system and a low-grade low-energy meandering floodplain. To capture the surface and subsurface heterogeneity of this headwaters system the basin has been modeled at a 10-meter resolution using ParFlow, a parallel, integrated hydrologic model. Driven by meteorological forcing, ParFlow is able to capture land surface processes and represents surface and subsurface interactions through saturated and variably saturated heterogeneous flow. Data from Digital Elevation Models (DEMs), land cover, permeability, geologic and soil maps, and on-site meteorological stations, were prepared, analyzed and input into ParFlow as layers with a grid size comprised of 1403 by 1685 cells to best represent the small-scale, high resolution model domain. Water table depth, soil moisture, soil temperature, snowpack, runoff and local energy budget values provide useful insight into the catchments response to the Intergovernmental Panel on Climate Change (IPCC) temperature projections. In the near term

  19. Influence of Inorganic Substrata Size, Leaf Litter and Woody Debris Removal on Benthic Invertebrates Resistance to Floods in Two Contrasting Headwater Streams

    NASA Astrophysics Data System (ADS)

    Bosco Imbert, J.; Gonzalez, Jose Manuel; Basaguren, Ana; Pozo, Jesus

    2005-02-01

    We studied the influence of inorganic substrata size, leaf litter and woody debris removal on the resistance of benthic invertebrates to floods in two contrasting forested headwater streams of the Agüera basin (northern Spain): Cuchillo stream (stream bed dominated by cobbles and pebbles) and Salderrey stream (stream bed dominated by bedrock and boulders). Generally, floods had a greater effect on benthic invertebrates resistance in the Salderrey stream, apparently due to the high presence of loose substrata overlaying bedrock and the higher scouring of sediment in this stream. Unlike Salderrey stream total number of individuals of Simuliidae, Echinogammarus tarragonensis and Protonemura spp. in riffles greatly increased at the reach scale in the Cuchillo stream after two floods, suggesting that Cuchillo was more retentive than Salderrey. A positive relationship between substrata size and invertebrate resistance to floods was found in the Cuchillo stream but not in the Salderrey stream. It appears that the flood disturbances in the Salderrey stream were too strong to find an increase in resistance as substrata size increased. Invertebrate resistance on leaf litter and resistance predictability were also higher in the Cuchillo stream; the former result suggests that retention of leaf packs was greater in the Cuchillo stream. The lack of a statistically significant effect of woody debris removal may imply that the composition and stability of inorganic substrata have more influence on invertebrate resistance to floods than woody debris at the reach scale in these headwater streams dominated by relatively stable substrata.

  20. Snow hydrology of a headwater Arctic basin. 1. Physical measurements and process studies

    SciTech Connect

    Kane, D.L.; Hinzman, L.D.; Benson, C.S.; Liston, G.E. )

    1991-06-01

    The hydrologic cycle of an Arctic watershed is dominated by such physical elements as snow, ice, permafrost, seasonally frozen soils, wide fluctuations in surface energy balance, and phase change of snow and ice to water. Hydrologic data collected over a 5-year period (1985-1989) from an Arctic watershed in northern Alaska are presented. Processes related to snow accumulation, redistribution, ablation, evaporation and subsequent snowmelt-generated runoff are discussed. The total water content of the snowpack at the end of winter had comprised between 28 and 40% of the annual precipitation. Redistribution of snow on the ground by the wind is a major factor in increasing the snowmelt runoff. Much of the redistributed snow accumulates in the valley bottom along the stream and also along depressions on the hillslopes. These depressions are small surface drainage channels that are referred to as water tracks. Partitioning of the snowmelt into runoff, evaporation and increased soil water storage in the active layer was carried out on the plot and watershed scale. Over a 5-year period, the volume of snowmelt runoff varied from 50 to 66% of the average watershed snowpack, while evaporation varied from 20 to 34% and soil moisture storage increased between 10 and 19%. Much greater variation in these hydrologic components occurred at the plot scale.

  1. Snow hydrology of a headwater Arctic basin. 2. Conceptual analysis and computer modeling

    SciTech Connect

    Hinzman, L.D.; Kane, D.L. )

    1991-06-01

    Lack of hydrologic data in the Arctic, particularly during snowmelt, severely limits modeling strategy. Spring snowmelt in Imnavait watershed is a very brief event, usually lasting about 10 days. Peak flow normally occurs within the top 10 cm of the highly organic soil mat or on the surface. Snow damming of snowmelt runoff is an important mechanism which must be considered in the modeling process of small watersheds. These unique characteristics of Arctic hydrology will affect the methodology and performance of a hydrologic model. The HBV model was used in an investigation of the hydrologic regime of an Arctic watershed during the spring snowmelt period. From the analysis of five spring melt events the authors found that HBV can adequately predict soil moisture, evaporation, snow ablation and accumulation, and runoff. It models the volumes of snowmelt runoff well, but more data are needed to improve the determination of snowmelt initiation. Use of HBV as a predictive tool is dependent upon the quality of the meteorologic forecast data.

  2. Creating a Population of 12-Digit Headwater Basins within the Albemarle-Pamlico Estuary System

    EPA Science Inventory

    Ecological research within the US Environmental Protection Agency's Office of Research and Development has recently changed its focus to quantifying and mapping ecosystem services provided to humans. Our local research group has been charged to develop a regional assessment of se...

  3. PCBS IN LAKE HARTWELL, SC, HEADWATERS OF THE SAVANNAH RIVER BASIN

    EPA Science Inventory

    Contamination due to polychlorinated biphenyls (PCBS) was discovered in the mid-1970s in the fish and sediments of Lake Hartwell, a U.S. Army Corps of Engineers reservoir on the border of South Carolina and Georgia that was formed from the Seneca and Tugaloo Rivers. Research by...

  4. Trace metals in upland headwater lakes in Ireland.

    PubMed

    Burton, Andrew; Aherne, Julian; Hassan, Nouri

    2013-10-01

    Trace elements (n = 23) in Irish headwater lakes (n = 126) were investigated to determine their ambient concentrations, fractionation (total, dissolved, and non-labile), and geochemical controls. Lakes were generally located in remote upland, acid-sensitive regions along the coastal margins of the country. Total trace metal concentrations were low, within the range of natural pristine surface waters; however, some lakes (~20 %) had inorganic labile aluminum and manganese at levels potentially harmful to aquatic organisms. Redundancy analysis indicated that geochemical weathering was the dominant controlling factor for total metals, compared with acidity for dissolved metals. In addition, many metals were positively correlated with dissolved organic carbon indicating their affinity (or complexation) with humic substances (e.g., aluminum, iron, mercury, lead). However, a number of trace metals (e.g., aluminum, mercury, zinc) were correlated with anthropogenic acidic deposition (i.e., non-marine sulfate), suggesting atmospheric sources or elevated leaching owing to acidic deposition. As transboundary air pollution continues to decline, significant changes in the cycling of trace metals is anticipated.

  5. Sources of hydroxyl radical in headwater streams from nitrogen-saturated forest.

    PubMed

    Chiwa, Masaaki; Higashi, Naoko; Otsuki, Kyoichi; Kodama, Hiroki; Miyajima, Tohru; Takeda, Kazuhiko; Sakugawa, Hiroshi

    2015-01-01

    Hydroxyl radical (HO) photoformation rate (RHO) was determined in headwater stream samples from nitrogen (N)-saturated forests, (1) to quantify the sources of HO in headwater streams and (2) to evaluate the nitrate NO3(-)-induced enhancement of HO formation in stream water caused by N saturation in forested watersheds. Stream water fulvic acid extracted from the forested watersheds was used to quantify the contribution of dissolved organic matter (DOM) to RHO. The results showed that almost all (97%; 81-109%) RHO sources in our headwater stream samples were quantitatively elucidated; the photolysis of NO3(-) (55%; 34-75%), nitrite [N(III)] (2%; 0.5-5.2%), and DOM-derived HO formation, from which photo-Fenton reactions (18%; 12-26%) and the direct photolysis of fluorescent dissolved organic matter (FDOM) (22%; 10-40%), was successfully separated. FDOM, which accounted for 53% (24-96%) of DOM in total organic carbon bases, was responsible for HO formation in our headwater streams. High NO3(-) leaching caused by N saturation in forested watersheds increased RHO in the headwaters, indicating that N-saturated forest could significantly change photoinduced and biogeochemical processes via enhanced HO formation in downstream water.

  6. Landscape influences on headwater streams on Fort Stewart, Georgia, USA

    SciTech Connect

    Jager, Yetta; Bevelhimer, Mark S; al., et.

    2011-01-01

    Military landscapes represent a mixture of undisturbed natural ecosystems, developed areas, and lands that support different types and intensities of military training. Research to understand water-quality influences of military landscapes usually involves intensive sampling in a few watersheds. In this study, we developed a survey design of accessible headwater watersheds intended to improve our ability to distinguish land water relationships in general, and training influences, in particular, on Fort Stewart, GA. We sampled and analyzed water from watershed outlets. We successfully developed correlative models for total suspended solids (TSS), total nitrogen (TN), organic carbon (OC), and organic nitrogen (ON), which dominated in this blackwater ecosystem. TSS tended to be greater in samples after rainfall and during the growing season, and models that included %Wetland suggested a build-and-flush relationship. We also detected a positive association between TSS and tank-training, which suggests a need to intercept sediment-laden runoff from training areas. Models for OC showed a negative association with %Grassland. TN and ON both showed negative associations with %Grassland, %Wetland, and %Forest. Unexpected positive associations were observed between OC and equipmenttraining activity and between ON and %Bare ground ? Roads. Future studies that combine our survey-based approach with more intensive monitoring of the timing and intensity of training would be needed to better understand the mechanisms for these empirical relationships involving military training. Looking beyond local effects on Fort Stewart streams, we explore questions about how exports of OC and nitrogen from coastal military installations ultimately influence estuaries downstream.

  7. Multi-objective Optimization of the Mississippi Headwaters Reservoir System

    NASA Astrophysics Data System (ADS)

    Faber, B. A.; Harou, J. J.

    2006-12-01

    The Hydrologic Engineering Center (HEC) of the U.S. Army Corps of Engineers is participating in a re- operation study of the Mississippi Headwaters reservoir system. The study, termed ROPE (Reservoir Operation Plan Evaluation), will develop a new operation policy for the reservoir system in a Shared Vision Planning effort. The current operating plan is 40 years old and does not account for the diverse objectives of the system altered by increased development and resource awareness. Functions of the six-reservoir system include flood damage reduction, recreation, fish and wildlife habitat considerations, tribal resources, water quality, water supply, erosion and sedimentation control, and hydropower production. Experience has shown that a modeling approach using both optimization, which makes decisions based on their value to objectives, and simulation, which makes decisions that follow operating instructions or rules, is an effective way to improve or develop new operating policies. HEC's role in this study was to develop a multi- objective optimization model of the system using HEC-PRM (Prescriptive Reservoir Model), a generalized computer program that performs multi-period deterministic network-flow optimization of reservoir systems. The optimization model's purpose is to enable stakeholders and decision makers to select appropriate tradeoffs between objectives, and have these tradeoffs reflected in proposed rules. Initial single-objective optimizations allow stakeholders to verify that the penalty functions developed by experts accurately represent their interests. Once penalty functions are confirmed, trade-off curves between pairs of system objectives are developed, and stakeholders and decision makers choose a desired balance between the two objectives. These chosen balance points are maintained in optimizations that consider all objectives. Finally, optimal system decisions are studied to infer operating patterns that embody the chosen tradeoffs. The

  8. Water balance of selected floodplain lake basins in the Middle Bug River valley

    NASA Astrophysics Data System (ADS)

    Dawidek, J.; Ferencz, B.

    2013-08-01

    This study is the first attempt in the literature on the subject of comparing water balance equations for floodplain lake basins depending on the type of connection the lake has to its parent river. Where confluent lakes (upstream connections) were concerned, it was only possible to apply a classic water balance equation. When dealing with contrafluent lakes (downstream connections) as well as lakes with a complex recharge type (contrafluent-confluent) modified equations were created. The hydrological type of a lake is decided by high water flow conditions and, consequently, the duration of potamophase (connection with a river) and limnophase (the isolation of the lake), which determine the values of particular components and the proportion of the vertical to horizontal water exchange rate. Confluent lakes are characterised by the highest proportion of horizontal components (the inflow and runoff of river water) to the vertical ones (precipitation and evaporation). The smallest differences occur with respect to a contrafluent lake. In the case of confluent lakes, the relationship between water balance components resulted from the consequent water flow through the basin, consistent with the slope of the river channel and valley. The supplying channels of contrafluent lakes had an obsequent character, which is why the flow rate was lower. Lakes with a complex, contrafluent-confluent recharge type showed intermediate features. After a period of slow contrafluent recharge, the inflow of water through a downstream crevasse from the area of the headwater of the river was activated; this caused a radical change of flow conditions into confluent ones. The conditions of water retention in lake basins were also varied. Apart from hydrological recharge, also the orographic features of the catchment areas of the lakes played an important role here, for example, the distance from the river channel, the altitude at which a given catchment was located within the floodplain and

  9. Processes and rates of sediment and wood accumulation in headwater streams of the Oregon Coast Range, USA

    USGS Publications Warehouse

    May, Christine L.; Gresswell, Robert E.

    2003-01-01

    Channels that have been scoured to bedrock by debris flows provide unique opportunities to calculate the rate of sediment and wood accumulation in low-order streams, to understand the temporal succession of channel morphology following disturbance, and to make inferences about processes associated with input and transport of sediment. Dendrochronology was used to estimate the time since the previous debris flow and the time since the last stand-replacement fire in unlogged basins in the central Coast Range of Oregon. Debris flow activity increased 42 per cent above the background rate in the decades immediately following the last wildfire. Changes in wood and sediment storage were quantified for 13 streams that ranged from 4 to 144 years since the previous debris flow. The volume of wood and sediment in the channel, and the length of channel with exposed bedrock, were strongly correlated with the time since the previous debris flow. Wood increased the storage capacity of the channel and trapped the majority of the sediment in these steep headwater streams. In the absence of wood, channels that have been scoured to bedrock by a debris flow may lack the capacity to store sediment and could persist in a bedrock state for an extended period of time. With an adequate supply of wood, low-order channels have the potential of storing large volumes of sediment in the interval between debris flows and can function as one of the dominant storage reservoirs for sediment in mountainous terrain.

  10. Bedrock Geologic Map of the Headwaters Region of the Cullasaja River, Macon and Jackson Counties, North Carolina

    USGS Publications Warehouse

    Burton, William C.

    2007-01-01

    The headwaters region of the Cullasaja River is underlain by metasedimentary and meta-igneous rocks of the Neoproterozoic Ashe Metamorphic Suite, including gneiss, schist, and amphibolite, that were intruded during Ordovician time by elongate bodies of trondhjemite, a felsic plutonic rock. Deformation, metamorphism, and intrusion occurred roughly simultaneously during the Taconic orogeny, about 470 million years ago, under upper-amphibolite-facies metamorphic conditions. Two generations of foliation and three major phases of folds are recognized. The second- and third-generation folds trend northeast and exert the most control on regional foliation trends. Since the orogeny, the region has undergone uplift, fracturing, and erosion. Resistance to erosion by the plutonic rock may be the primary reason for the relatively gentle relief of the high-elevation basin, compared to surrounding areas. Amphibolite is the most highly fractured lithology, followed by trondhjemite; the latter may have the best ground-water potential of the mapped lithologies by virtue of its high fracture density and high proportion of subhorizontal fractures.

  11. The Estimated Likelihood of Nutrients and Pesticides in Nontidal Headwater Streams of the Maryland Coastal Plain During Base Flow

    EPA Science Inventory

    Water quality in nontidal headwater (first-order) streams of the Coastal Plain during base flow in the late winter and spring is related to land use, hydrogeology, and other natural or human influences in contributing watersheds. A random survey of 174 headwater streams of the Mi...

  12. Physical and temporal isolation of mountain headwater streams in the western Mojave Desert, Southern California

    USGS Publications Warehouse

    Izbicki, J.A.

    2007-01-01

    Streams draining mountain headwater areas of the western Mojave Desert are commonly physically isolated from downstream hydrologic systems such as springs, playa lakes, wetlands, or larger streams and rivers by stream reaches that are dry much of the time. The physical isolation of surface flow in these streams may be broken for brief periods after rainfall or snowmelt when runoff is sufficient to allow flow along the entire stream reach. Despite the physical isolation of surface flow in these streams, they are an integral part of the hydrologic cycle. Water infiltrated from headwater streams moves through the unsaturated zone to recharge the underlying ground-water system and eventually discharges to support springs, streamflow, isolated wetlands, or native vegetation. Water movement through thick unsaturated zones may require several hundred years and subsequent movement through the underlying ground-water systems may require many thousands of years - contributing to the temporal isolation of mountain headwater streams. ?? 2007 American Water Resources Association.

  13. Modeling flash flood events in an ungaged semi-arid basin using a real-time distributed model: Fish Creek near Anza Borrego, California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fast responding headwater basins and canyons pose a significant threat to life and property throughout the semi-arid western United States. This paper presents the results from the application of the real-time distributed model KINematic runoff and EROsin model (KINEROS2) to the complex terrain of t...

  14. Climatic Variation And Runoff From Himalayan Mountain Basins

    NASA Astrophysics Data System (ADS)

    Bolton, L.; Collins, D. N.; Davenport, J.; Entwistle, N. S.

    2012-12-01

    Both precipitation and runoff usually increase with elevation in high mountain basins but Himalayan tributaries of both Indus and Ganges often rise in relatively dry interior areas, before flow downstream is modified on passing through areas receiving winter snowfall and summer monsoon snow and rain. Through time variations in tributary contributions to the major rivers, the upper Indus, Jhelum, Sutlej and Ganges therefore respond to differing climatic signals. Long term measurements of discharge upstream of large dams are available for the Jhelum and Sutlej since the 1920s, but show differing patterns of variation. Runoff in the Jhelum declined to the 1960s before recovering whereas flow in the Sutlej continued to decline. Highly glacierised areas south-east of Nanga Parbat receive considerable amounts of precipitation distributed throughout the year whereas other Jhelum headwaters and those of the Sutlej are summer monsoon dominated. Precipitation measurements exist for dry areas of the upper Indus basin since the early 1900s, but other measurements in the Kaghan valley and upstream of the Mangla dam only start in the 1960s. Correlation between year-to-year variations in precipitation across these headwater regions and between precipitation and runoff in headwater and main-stem basins suggest that runoff declines with summer snowfall on glaciers in areas of the Upper Indus where valleys at elevations below glaciers are dry, but runoff increases with summer precipitation south of the main Himalaya range in the Jhelum and Sutlej. Considerable differences arise therefore in water resources availability from year to year in the various basins downstream.

  15. Predicting fine-scale distributions of peripheral aquatic species in headwater streams

    USGS Publications Warehouse

    DeRolph, Christopher R.; Nelson, S.; Kwak, Thomas J.; Hain, Ernie F.

    2015-01-01

    Headwater species and peripheral populations that occupy habitat at the edge of a species range may hold an increased conservation value to managers due to their potential to maximize intraspecies diversity and species' adaptive capabilities in the context of rapid environmental change. The southern Appalachian Mountains are the southern extent of the geographic range of native Salvelinus fontinalis and naturalized Oncorhynchus mykiss and Salmo trutta in eastern North America. We predicted distributions of these peripheral, headwater wild trout populations at a fine scale to serve as a planning and management tool for resource managers to maximize resistance and resilience of these populations in the face of anthropogenic stressors. We developed correlative logistic regression models to predict occurrence of brook trout, rainbow trout, and brown trout for every interconfluence stream reach in the study area. A stream network was generated to capture a more consistent representation of headwater streams. Each of the final models had four significant metrics in common: stream order, fragmentation, precipitation, and land cover. Strahler stream order was found to be the most influential variable in two of the three final models and the second most influential variable in the other model. Greater than 70% presence accuracy was achieved for all three models. The underrepresentation of headwater streams in commonly used hydrography datasets is an important consideration that warrants close examination when forecasting headwater species distributions and range estimates. Additionally, it appears that a relative watershed position metric (e.g., stream order) is an important surrogate variable (even when elevation is included) for biotic interactions across the landscape in areas where headwater species distributions are influenced by topographical gradients.

  16. Predicting fine-scale distributions of peripheral aquatic species in headwater streams

    SciTech Connect

    DeRolph, Christopher R.; Nelson, Stacy A. C.; Kwak, Thomas J.; Hain, Ernie F.

    2014-12-09

    Headwater species and peripheral populations that occupy habitat at the edge of a species range may hold an increased conservation value to managers due to their potential to maximize intraspecies diversity and species' adaptive capabilities in the context of rapid environmental change. The southern Appalachian Mountains are the southern extent of the geographic range of native Salvelinus fontinalis and naturalized Oncorhynchus mykiss and Salmo trutta in eastern North America. In this paper, we predicted distributions of these peripheral, headwater wild trout populations at a fine scale to serve as a planning and management tool for resource managers to maximize resistance and resilience of these populations in the face of anthropogenic stressors. We developed correlative logistic regression models to predict occurrence of brook trout, rainbow trout, and brown trout for every interconfluence stream reach in the study area. A stream network was generated to capture a more consistent representation of headwater streams. Each of the final models had four significant metrics in common: stream order, fragmentation, precipitation, and land cover. Strahler stream order was found to be the most influential variable in two of the three final models and the second most influential variable in the other model. Greater than 70% presence accuracy was achieved for all three models. The underrepresentation of headwater streams in commonly used hydrography datasets is an important consideration that warrants close examination when forecasting headwater species distributions and range estimates. Finally and additionally, it appears that a relative watershed position metric (e.g., stream order) is an important surrogate variable (even when elevation is included) for biotic interactions across the landscape in areas where headwater species distributions are influenced by topographical gradients.

  17. Predicting fine-scale distributions of peripheral aquatic species in headwater streams

    DOE PAGES

    DeRolph, Christopher R.; Nelson, Stacy A. C.; Kwak, Thomas J.; ...

    2014-12-09

    Headwater species and peripheral populations that occupy habitat at the edge of a species range may hold an increased conservation value to managers due to their potential to maximize intraspecies diversity and species' adaptive capabilities in the context of rapid environmental change. The southern Appalachian Mountains are the southern extent of the geographic range of native Salvelinus fontinalis and naturalized Oncorhynchus mykiss and Salmo trutta in eastern North America. In this paper, we predicted distributions of these peripheral, headwater wild trout populations at a fine scale to serve as a planning and management tool for resource managers to maximize resistancemore » and resilience of these populations in the face of anthropogenic stressors. We developed correlative logistic regression models to predict occurrence of brook trout, rainbow trout, and brown trout for every interconfluence stream reach in the study area. A stream network was generated to capture a more consistent representation of headwater streams. Each of the final models had four significant metrics in common: stream order, fragmentation, precipitation, and land cover. Strahler stream order was found to be the most influential variable in two of the three final models and the second most influential variable in the other model. Greater than 70% presence accuracy was achieved for all three models. The underrepresentation of headwater streams in commonly used hydrography datasets is an important consideration that warrants close examination when forecasting headwater species distributions and range estimates. Finally and additionally, it appears that a relative watershed position metric (e.g., stream order) is an important surrogate variable (even when elevation is included) for biotic interactions across the landscape in areas where headwater species distributions are influenced by topographical gradients.« less

  18. Predicting fine-scale distributions of peripheral aquatic species in headwater streams

    PubMed Central

    DeRolph, Christopher R; Nelson, Stacy A C; Kwak, Thomas J; Hain, Ernie F

    2015-01-01

    Headwater species and peripheral populations that occupy habitat at the edge of a species range may hold an increased conservation value to managers due to their potential to maximize intraspecies diversity and species' adaptive capabilities in the context of rapid environmental change. The southern Appalachian Mountains are the southern extent of the geographic range of native Salvelinus fontinalis and naturalized Oncorhynchus mykiss and Salmo trutta in eastern North America. We predicted distributions of these peripheral, headwater wild trout populations at a fine scale to serve as a planning and management tool for resource managers to maximize resistance and resilience of these populations in the face of anthropogenic stressors. We developed correlative logistic regression models to predict occurrence of brook trout, rainbow trout, and brown trout for every interconfluence stream reach in the study area. A stream network was generated to capture a more consistent representation of headwater streams. Each of the final models had four significant metrics in common: stream order, fragmentation, precipitation, and land cover. Strahler stream order was found to be the most influential variable in two of the three final models and the second most influential variable in the other model. Greater than 70% presence accuracy was achieved for all three models. The underrepresentation of headwater streams in commonly used hydrography datasets is an important consideration that warrants close examination when forecasting headwater species distributions and range estimates. Additionally, it appears that a relative watershed position metric (e.g., stream order) is an important surrogate variable (even when elevation is included) for biotic interactions across the landscape in areas where headwater species distributions are influenced by topographical gradients. PMID:25628872

  19. Cichlid fishes in the Angolan headwaters region: molecular evidence of the ichthyofaunal contact between the Cuanza and Okavango-Zambezi systems.

    PubMed

    Musilová, Zuzana; Kalous, Lukáš; Petrtýl, Miloslav; Chaloupková, Petra

    2013-01-01

    The headwaters of five large African river basins flow through the Bié Plateau in Angola and still remain faunistically largely unexplored. We investigated fish fauna from the Cuanza and Okavango-Zambezi river systems from central Angola. We reconstructed molecular phylogenies of the most common cichlid species from the region, Tilapia sparrmanii and Serranochromis macrocephalus, using both mitochondrial and nuclear markers. We found evidence for ichthyofaunal contact and gene flow between the Cuanza and Okavango-Zambezi watersheds in the Bié Plateau in central Angola. Waterfalls and rapids also appeared to restrict genetic exchange among populations within the Cuanza basin. Further, we found that the Angolan Serranochromis cichlid fishes represent a monophyletic lineage with respect to other haplochromines, including the serranochromines from the Congo and Zambezi rivers. This study represents an important initial step in a biodiversity survey of this extremely poorly explored region, as well as giving further understanding to species distributions and gene flow both between and within river basins.

  20. Longitudinal Distribution of Wood along Headwater Streams in the Colorado Front Range

    NASA Astrophysics Data System (ADS)

    Wohl, E.; Jaeger, K. L.

    2007-12-01

    Wood loading, channel parameters, and valley parameters were surveyed in 50 contiguous stream segments each 25 m in length along 12 streams in the Colorado Front Range. Length and diameter of each piece of wood were measured, and the orientation of each piece was tallied as a ramp, sunken, bridge, or floater. These data were then used to evaluate basin- and local-scale controls on wood loading, as well as longitudinal patterns of wood distribution in forested headwater streams of the Colorado Front Range. We hypothesized that wood would be non-uniformly distributed as a result of the presence of wood jams and greater numbers of individual pieces in some segments of the stream, and that the degree of non-uniformity would vary among channels in correlation with variations in channel width, gradient, and drainage area as these parameters reflect relative capacity of a stream to transport wood introduced from the adjacent riparian zone and valley bottom. Analyses of the longitudinal uniformity of wood distribution are ongoing. Multiple regression models to evaluate controls on wood loading used either a stream-wide average or data from all 50 segments on each stream. Models that used an average for each of the 12 streams indicated that wood loading correlates most strongly with drainage area, average slope, channel width, and elevation. When all 600 stream segments were included in the multiple regression, the presence of a jam, diameter at breast height (DBH) of trees in the riparian zone, channel width, and stream gradient correlate most strongly with wood loading. Trends in sets of analyses indicate that wood loading is higher for smaller drainage areas, steeper stream gradients, narrower channels, higher elevations, the presence of a jam, and greater DBH values. Each of these correlations is physically reasonable in that smaller drainage areas and narrow channels likely have lower transport capacity, steeper streams and those with jams are hydraulically rougher and

  1. Carbon fluxes in an acid rain impacted boreal headwater catchment

    NASA Astrophysics Data System (ADS)

    Marx, Anne; Hintze, Simone; Jankovec, Jakub; Sanda, Martin; Dusek, Jaromir; Vogel, Tomas; van Geldern, Robert; Barth, Johannes A. C.

    2016-04-01

    Terrestrial carbon export via inland aquatic systems is a key process in the budget of the global carbon cycle. This includes loss of carbon to the atmosphere via gas evasion from rivers or reservoirs as well as carbon fixation in freshwater sediments. Headwater streams are the first endmembers of the transition of carbon between soils, groundwater and surface waters and the atmosphere. In order to quantify these processes the experimental catchment Uhlirska (1.78 km2) located in the northern Czech Republic was studied. Dissolved inorganic, dissolved organic and particulate organic carbon (DIC, DOC, POC) concentrations and isotopes were analyzed in ground-, soil -and stream waters between 2014 and 2015. In addition, carbon dioxide degassing was quantified via a stable isotope modelling approach. Results show a discharge-weighted total carbon export of 31.99 g C m-2 yr-1 of which CO2 degassing accounts 79 %. Carbon isotope ratios (δ13C) of DIC, DOC, and POC (in ‰ VPDB) ranged from -26.6 to -12.4 ‰ from -29.4 to -22.7 ‰ and from -30.6 to -26.6 ‰ respectively. The mean values for DIC are -21.8 ±3.8 ‰ -23.6 ±0.9 ‰ and -19.5 ±3.0 ‰ for soil, shallow ground and surface water compartments. For DOC, these compartments have mean values of -27.1 ±0.3 ‰ -27.0 ±0.8 ‰ and -27.4 ±0.7 ‰Ṁean POC value of shallow groundwaters and surface waters are -28.8 ±0.8 ‰ and -29.3 ±0.5 ‰ respectively. These isotope ranges indicate little turnover of organic material and predominant silicate weathering. The degassing of CO2 caused an enrichment of the δ13C-DIC values of up to 6.8 ‰ between a catchment gauge and the catchment outlet over a distance of 866 m. In addition, the Uhlirska catchment has only negligible natural sources of sulphate, yet SO42- accounts for 21 % of major stream water ions. This is most likely a remainder from acid rain impacts in the area.

  2. Hydrologic data for Paleozoic rocks in the upper Colorado River basin, Colorado, Utah, Wyoming, and Arizona

    USGS Publications Warehouse

    Geldon, Arthur L.

    1989-01-01

    This report contains data used to interpret the hydrology of Paleozoic rocks in the Upper Colorado River Basin under the U.S. Geological Survey 's Regional Aquifer-System Analysis program. The study area includes the drainages of the Green and Colorado Rivers from their headwaters to Lees Ferry, Arizona. Hydrologic data presented in this report include artesian yields from wells and springs, and values of porosity, intrinsic permeability, and hydraulic conductivity determined by laboratory analyses and aquifer tests. (USGS)

  3. Influence of instream habitat and water quality on aggressive behavior in crayfish of channelized headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many agricultural drainage ditches that border farm fields of the Midwestern United States are degraded headwater streams that possess communities of crayfish. We hypothesized that crayfish communities at sites with low instream habitat diversity and poor water quality would show greater evidence of...

  4. A synoptic survey of ecosystem services from headwater catchments in the United States

    EPA Science Inventory

    We combined data collected from 568 headwater streams as a part of the US Environmental Protection Agency’s National Rivers and Streams Assessment (NRSA) with catchment attributes related to the production of the ecosystem services of water supply, carbon, nitrogen, and phosphoru...

  5. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Mississippi River; use and administration. 207.340 Section 207.340 Navigation and Navigable Waters CORPS OF... headwaters of the Mississippi River; use and administration. (a) Description. These reservoirs include Winnibigoshish, Leech Lake, Pokegama, Sandy Lake, Pine River and Gull Lake. (b) Penalties. The River and...

  6. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Mississippi River; use and administration. 207.340 Section 207.340 Navigation and Navigable Waters CORPS OF... headwaters of the Mississippi River; use and administration. (a) Description. These reservoirs include Winnibigoshish, Leech Lake, Pokegama, Sandy Lake, Pine River and Gull Lake. (b) Penalties. The River and...

  7. 33 CFR 207.340 - Reservoirs at headwaters of the Mississippi River; use and administration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Mississippi River; use and administration. 207.340 Section 207.340 Navigation and Navigable Waters CORPS OF... headwaters of the Mississippi River; use and administration. (a) Description. These reservoirs include Winnibigoshish, Leech Lake, Pokegama, Sandy Lake, Pine River and Gull Lake. (b) Penalties. The River and...

  8. 78 FR 42030 - Reservoirs at Headwaters of the Mississippi River; Use and Administration

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-15

    ...--Mississippi River Headwater Reservoir System Operating Limits and CFR Versus ROPE Minimum Discharges Winni... deleting from the Code of Federal Regulations all references to minimum discharges and to operating limits... of the Corps of Engineers recently adopted an updated operating plan for the Mississippi...

  9. Linking nitrogen management, seep chemistry, and stream water quality in two agricultural headwater watersheds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian seepage zones in headwater agricultural watersheds represent important sources of nitrate-nitrogen (NO3-N) to surface waters, often connecting N-rich groundwater systems to streams. In this study, we examined how NO3-N concentrations in seep and stream water were affected by NO3-N processin...

  10. An Assessment of Cellulose Filters as a Standardized Material for Measuring Litter Breakdown in Headwater Streams

    EPA Science Inventory

    The decay rate of cellulose filters and associated chemical and biological characteristics were compared to those of white oak (Quercus alba) leaves to determine if cellulose filters could be a suitable standardized material for measuring deciduous leaf breakdown in headwater str...

  11. An assessment of cellulose filters as a standardized material for measuring litter breakdown in headwater streams

    EPA Science Inventory

    The decay rate of cellulose filters and associated chemical and biological characteristics were compared to those of white oak (Quercus alba) leaves to determine if cellulose filters could be a suitable standardized material for measuring deciduous leaf breakdown in headwater str...

  12. FIELD OPERATIONS MANUAL FOR ASSESSING THE HYDROLOGIC PERMANENCE AND ECOLOGICAL CONDITION OF HEADWATER STREAMS

    EPA Science Inventory

    The purpose of this manual is to document procedures that were developed and used by the Ecological Exposure Research Division, NERL, ORD, for the assessment of the physical and biological characteristics of headwater streams; and to provide a catalog of procedures to other group...

  13. High frequency variability of environmental drivers determining benthic community dynamics in headwater streams.

    PubMed

    Snell, M A; Barker, P A; Surridge, B W J; Large, A R G; Jonczyk, J; Benskin, C McW H; Reaney, S; Perks, M T; Owen, G J; Cleasby, W; Deasy, C; Burke, S; Haygarth, P M

    2014-07-01

    Headwater streams are an important feature of the landscape, with their diversity in structure and associated ecological function providing a potential natural buffer against downstream nutrient export. Phytobenthic communities, dominated in many headwaters by diatoms, must respond to physical and chemical parameters that can vary in magnitude within hours, whereas the ecological regeneration times are much longer. How diatom communities develop in the fluctuating, dynamic environments characteristic of headwaters is poorly understood. Deployment of near-continuous monitoring technology in sub-catchments of the River Eden, NW England, provides the opportunity for measurement of temporal variability in stream discharge and nutrient resource supply to benthic communities, as represented by monthly diatom samples collected over two years. Our data suggest that the diatom communities and the derived Trophic Diatom Index, best reflect stream discharge conditions over the preceding 18-21 days and Total Phosphorus concentrations over a wider antecedent window of 7-21 days. This is one of the first quantitative assessments of long-term diatom community development in response to continuously-measured stream nutrient concentration and discharge fluctuations. The data reveal the sensitivity of these headwater communities to mean conditions prior to sampling, with flow as the dominant variable. With sufficient understanding of the role of antecedent conditions, these methods can be used to inform interpretation of monitoring data, including those collected under the European Water Framework Directive and related mitigation efforts.

  14. Are bryophytes useful indicators of hydrologic permanence in forested headwater streams?

    EPA Science Inventory

    Court cases have recently questioned whether all headwater streams, particularly non-perennial streams, should be protected in the U.S. under the Clean Water Act. Rapid field-based indicators of hydrologic permanence are needed for jurisdictional determinations. The study objecti...

  15. Variability of water quality across headwater catchments with distinct soils and hydrologic systems in central Missouri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface water and groundwater contamination by herbicides and fertilizers continues to be a major water quality problem in central Missouri. The purpose of this study was to examine spatial variability of water quality among three different headwater catchments – Goodwater Creek Experimental Watersh...

  16. Estimating contributions of nitrate and herbicides from groundwater to headwater streams, northern Atlantic Coastal Plain, USA

    USGS Publications Warehouse

    Ator, Scott; Denver, Judith M.

    2012-01-01

    Groundwater transport often complicates understanding of surface-water contamination. We estimated the regional flux of nitrate and selected herbicides from groundwater to nontidal headwater streams of the Atlantic Coastal Plain (New Jersey through North Carolina) based on late-winter or spring base-flow samples from 174 streams. Sampled streams were selected randomly, and flux estimates are based on resulting population estimates rather than on empirical models, which have been used previously for similar estimates. Base-flow flux in the estimated 8,834 headwater streams of the study area are an estimated 21,200 kg/day of nitrate (as N) and 5.83, 0.565, and 20.7 kg/day of alachlor, atrazine, and metolachlor (and selected degradates), respectively. Base-flow flux of alachlor and metolachlor is <3% of the total base-flow flux of those compounds plus degradates. Base-flow flux of nitrate and herbicides as a percentage of applications is typically highest in well-drained areas and lowest in areas with abundant poor drainage and anoxic conditions. In Coastal Plain watersheds of Albemarle and Pamlico Sounds, <2% of applied nitrogen reaches headwater streams as base flow. On the Delmarva Peninsula part of the Chesapeake Bay watershed, however, more than 10% of such applications are transported through groundwater to streams, and base-flow nitrate flux represents 70% of total nitrogen flux in headwater streams.

  17. Hydrologic response of hillslope seeps and headwater streams of the Fort Worth Prairie

    NASA Astrophysics Data System (ADS)

    Slattery, Michael; Jones, Shannon

    2015-04-01

    There has been minimal research on the relationships among vegetation, topography, and hydrology of hillslope seeps and headwater streams in general, and in the Fort Worth Prairie ecoregion in particular. Unlike traditional descriptions of Midwestern tallgrass prairies, these riparian zones are often dominated by annuals. Due to the ephemeral or intermittent nature of headwater stream hydrology, the high variation of soil moisture restricts tallgrasses from dominating riparian zones. In this study we quantify the hydrologic regime of a Fort Worth Prairie hillslope hollow by analyzing the spatio-temporal response of soil moisture to precipitation and drying, its impact on runoff generation, and the vegetation-soil moisture relationship. We conducted the study between August 2012 to March 2013, under drought-like conditions that prevented streamflow. Results show that, despite extreme moisture stress, the hillslope seep completely saturates during wet periods and saturates along the hillslope base during dry conditions. Autumn vegetation most accurately aligns with moderate soil moisture conditions. This research describes Fort Worth Prairie headwater stream and seep habitats and provides a basis for how they function hydrologically to create a foundation for improved habitat management, protection, and restoration of riparian headwaters in North Central Texas.

  18. Influence of riparian seepage zones on nitrate variability in two agricultural headwater streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riparian seepage zones are one of the primary pathways of groundwater transport to headwater streams. While seeps have been recognized for their contributions to streamflow, there is little information on how seeps affect stream water quality. The objective of this study was to examine the influence...

  19. Spatial Variability of Dissolved Organic Carbon in Headwater Wetlands in Central Pennsylvania

    NASA Astrophysics Data System (ADS)

    Reichert-Eberhardt, A. J.; Wardrop, D.; Boyer, E. W.

    2011-12-01

    Dissolved organic carbon (DOC) is known to be of an important factor in many microbially mediated biochemical processes, such as denitrification, that occur in wetlands. The spatial variability of DOC within a wetland could impact the microbes that fuel these processes, which in turn can affect the ecosystem services provided by wetlands. However, the amount of spatial variability of DOC in wetlands is generally unknown. Furthermore, it is unknown how disturbance to wetlands can affect spatial variability of DOC. Previous research in central Pennsylvania headwater wetland soils has shown that wetlands with increased human disturbance had decreased heterogeneity in soil biochemistry. To address groundwater chemical variability 20 monitoring wells were installed in a random pattern in a 400 meter squared plot in a low-disturbance headwater wetland and a high-disturbance headwater wetland in central Pennsylvania. Water samples from these wells will be analyzed for DOC, dissolved inorganic carbon, nitrate, ammonia, and sulfate concentrations, as well as pH, conductivity, and temperature on a seasonal basis. It is hypothesized that there will be greater spatial variability of groundwater chemistry in the low disturbance wetland than the high disturbance wetland. This poster will present the initial data concerning DOC spatial variability in both the low and high impact headwater wetlands.

  20. 18 CFR 11.11 - Energy gains method of determining headwater benefits charges.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Energy gains method of determining headwater benefits charges. 11.11 Section 11.11 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT ANNUAL CHARGES UNDER PART I OF THE FEDERAL...

  1. Significance of headwater streams and perennial springs in ecological monitoring in Shenandoah National Park

    USGS Publications Warehouse

    Snyder, Craig D.; Webb, James R.; Young, John A.; Johnson, Zane B.

    2013-01-01

    Shenandoah National Park has been monitoring water chemistry and benthic macroinvertebrates in stream ecosystems since 1979. These monitoring efforts were designed to assess the status and trends in stream condition associated with atmospheric deposition (acid rain) and changes in forest health due to gypsy moth infestations. The primary objective of the present research was to determine whether the current long-term macroinvertebrate and water-quality monitoring program in Shenandoah National Park was failing to capture important information on the status and trends in stream condition by not sufficiently representing smaller, headwater streams. The current benthic-macroinvertebrate and water-chemistry sampling designs do not include routine collection of data from streams with contributing watershed areas smaller than 100 hectares, even though these small streams represent the overwhelming proportion of total stream length in the park. In this study, we sampled headwater sites, including headwater stream reaches (contributing watershed area approximately 100 hectares (ha) and perennial springs, in the park for aquatic macroinvertebrates and water chemistry and compared the results with current and historical data collected at long-term ecological monitoring (LTEM) sites on larger streams routinely sampled as part of ongoing monitoring efforts. The larger purpose of the study was to inform ongoing efforts by park managers to evaluate the effectiveness and efficiency of the current aquatic monitoring program in light of other potential stressors (for example, climate change) and limited resources. Our results revealed several important findings that could influence management decisions regarding long-term monitoring of park streams. First, we found that biological indicators of stream condition at headwater sites and perennial springs generally were more indicative of lower habitat quality and were more spatially variable than those observed at sites on routinely

  2. Arthropod prey for riparian associated birds in headwater forests of the Oregon Coast Range

    USGS Publications Warehouse

    Hagar, Joan C.; Li, Judith; Sobota, Janel; Jenkins, Stephanie

    2012-01-01

    Headwater riparian areas occupy a large proportion of the land base in Pacific Northwest forests, and thus are ecologically and economically important. Although a primary goal of management along small headwater streams is the protection of aquatic resources, streamside habitat also is important for many terrestrial wildlife species. However, mechanisms underlying the riparian associations of some terrestrial species have not been well studied, particularly for headwater drainages. We investigated the diets of and food availability for four bird species associated with riparian habitats in montane coastal forests of western Oregon, USA. We examined variation in the availability of arthropod prey as a function of distance from stream. Specifically, we tested the hypotheses that (1) emergent aquatic insects were a food source for insectivorous birds in headwater riparian areas, and (2) the abundances of aquatic and terrestrial arthropod prey did not differ between streamside and upland areas during the bird breeding season. We found that although adult aquatic insects were available for consumption throughout the study period, they represented a relatively small proportion of available prey abundance and biomass and were present in only 1% of the diet samples from only one of the four riparian-associated bird species. Nonetheless, arthropod prey, comprised primarily of insects of terrestrial origin, was more abundant in streamside than upland samples. We conclude that food resources for birds in headwater riparian areas are primarily associated with terrestrial vegetation, and that bird distributions along the gradient from streamside to upland may be related to variation in arthropod prey availability. Because distinct vegetation may distinguish riparian from upland habitats for riparian-associated birds and their terrestrial arthropod prey, we suggest that understory communities be considered when defining management zones for riparian habitat.

  3. Mean annual runoff in the upper Ohio River basin, 1941-70, and its historic variation

    USGS Publications Warehouse

    Beall, Robert M.

    1976-01-01

    A map of the Ohio River basin above the Muskingum River shows patterns of mean annual runoff for the climatologic and hydrologic reference period, 1941-70. The primary data base consisted of 98 long-term gaging-station records collected within this 27,300-square-mile headwater area of the Ohio River basin. Supplemental information was derived from 83 short-term records. Mean annual runoff is at a regional minimum of less than 12 inches in an area extending from the northern West Virginia panhandle to the headwaters of the Mahoning River in Ohio. Mean annual runoff of more than 32 inches occurs in parts of the upper Cheat River basin in West Virginia. The zone of high runoff trends northeastward along the western slopes of the Allegheny Mountains; magnitudes diminish to about 25 inches at the eastern basin boundary near Ebensburg, Pennsylvania. Runoff of this magnitude occurs also in a band across the upper Allegheny River basin in Pennsylvania. Ratios of mean annual discharge to the 30-year reference-period average were computed for each year of record for all long-term gaging stations. Annual discharges have ranged from about 30 percent to 200 percent of the 30-year mean. Graphed summaries of the annual ratios document the relative duration and magnitude of wet and dry periods during the past 65 years in the upper Ohio River basin. (Woodard-USGS)

  4. Hydrologic response to valley-scale structure in alpine headwaters

    USGS Publications Warehouse

    Weekes, Anne A.; Torgersen, Christian E.; Montgomery, David R.; Woodward, Andrea; Bolton, Susan M.

    2015-01-01

    To better evaluate potential differences in streamflow response among basins with extensive coarse depositional features and those without, we examined the relationships between streamflow discharge, stable isotopes, water temperature and the amplitude of the diurnal signal at five basin outlets. We also quantified the percentages of colluvial channel length measured along the stepped longitudinal profile. Colluvial channels, characterized by the presence of surficial, coarse-grained depositional features, presented sediment-rich, transport-limited morphologies that appeared to have a cumulative effect on the timing and volume of flow downstream. Measurements taken from colluvial channels flowing through depositional landforms showed median recession constants (Kr) of 0.9-0.95, δ18O values of ≥−14.5 and summer diurnal amplitudes ≤0.8 as compared with more typical surface water recession constant values of 0.7, δ18O ≤ −13.5 and diurnal amplitudes >2.0. Our results demonstrated strong associations between the percentage of colluvial channel length within a catchment and moderated streamflow regimes, water temperatures, diurnal signals and depleted δ18O related to groundwater influx.

  5. Climate Change and Its Impact on the Eco-Environment of the Three-Rivers Headwater Region on the Tibetan Plateau, China.

    PubMed

    Jiang, Chong; Zhang, Linbo

    2015-09-25

    This study analyzes the impact of climate change on the eco-environment of the Three-Rivers Headwater Region (TRHR), Tibetan Plateau, China. Temperature and precipitation experienced sharp increases in this region during the past 57 years. A dramatic increase in winter temperatures contributed to a rise in average annual temperatures. Moreover, annual runoff in the Lancang (LRB) and Yangtze (YARB) river basins showed an increasing trend, compared to a slight decrease in the Yellow River Basin (YRB). Runoff is predominantly influenced by rainfall, which is controlled by several monsoon systems. The water temperature in the YRB and YARB increased significantly from 1958 to 2007 (p < 0.001), driven by air temperature changes. Additionally, owing to warming and wetting trends in the TRHR, the net primary productivity (NPP) and normalized difference vegetation index (NDVI) showed significant increasing trends during the past half-century. Furthermore, although an increase in water erosion due to rainfall erosivity was observed, wind speeds declined significantly, causing a decline in wind erosion, as well as the frequency and duration of sandstorms. A clear regional warming trend caused an obvious increasing trend in glacier runoff, with a maximum value observed in the 2000s.

  6. Climate Change and Its Impact on the Eco-Environment of the Three-Rivers Headwater Region on the Tibetan Plateau, China

    PubMed Central

    Jiang, Chong; Zhang, Linbo

    2015-01-01

    This study analyzes the impact of climate change on the eco-environment of the Three-Rivers Headwater Region (TRHR), Tibetan Plateau, China. Temperature and precipitation experienced sharp increases in this region during the past 57 years. A dramatic increase in winter temperatures contributed to a rise in average annual temperatures. Moreover, annual runoff in the Lancang (LRB) and Yangtze (YARB) river basins showed an increasing trend, compared to a slight decrease in the Yellow River Basin (YRB). Runoff is predominantly influenced by rainfall, which is controlled by several monsoon systems. The water temperature in the YRB and YARB increased significantly from 1958 to 2007 (p < 0.001), driven by air temperature changes. Additionally, owing to warming and wetting trends in the TRHR, the net primary productivity (NPP) and normalized difference vegetation index (NDVI) showed significant increasing trends during the past half-century. Furthermore, although an increase in water erosion due to rainfall erosivity was observed, wind speeds declined significantly, causing a decline in wind erosion, as well as the frequency and duration of sandstorms. A clear regional warming trend caused an obvious increasing trend in glacier runoff, with a maximum value observed in the 2000s. PMID:26404333

  7. BIODIVERSITY MANAGEMENT APPROACHES FOR STREAM-RIPARIAN AREAS: PERSPECTIVES FOR PACIFIC NORTHWEST HEADWATER FORESTS, MICROCLIMATES, AND AMPHIBIANS

    EPA Science Inventory

    Stream-riparian areas represent a nexus of biodiversity, with disproportionate numbers of species tied to and interacting within this key habitat. New research in Pacific Northwest headwater forests, especially the characterization of microclimates and amphibian distributions, is...

  8. Selected elements and organic chemicals in bed sediment and fish tissue of the Tualatin River basin, Oregon, 1992-96

    USGS Publications Warehouse

    Bonn, Bernadine A.

    1999-01-01

    This report describes the results of a reconnaissance survey of elements and organic compounds found in bed sediment and fish tissue in streams of the Tualatin River Basin. The basin is in northwestern Oregon to the west of the Portland metropolitan area (fig. 1). The Tualatin River flows for about 80 miles, draining an area of about 712 square miles, before it enters the Willamette River. Land use in the basin changes from mostly forested in the headwaters, to mixed forest and agriculture, to predominately urban. The basin supports a growing population of more than 350,000 people, most of whom live in lower parts of the basin. Water quality in the Tualatin River and its tributaries is expected to be affected by the increasing urbanization of the basin.

  9. Reproductive effects of oestrogenic endocrine disrupting chemicals in Astyanax rivularis inhabiting headwaters of the Velhas River, Brazil.

    PubMed

    Weber, André Alberto; Moreira, Davidson Peruci; Melo, Rafael Magno Costa; Vieira, Augusto Bicalho Cruz; Prado, Paula Suzanna; da Silva, Mirra Angelina Neres; Bazzoli, Nilo; Rizzo, Elizete

    2017-03-21

    The Velhas River is the most polluted river in the state of Minas Gerais, south-eastern Brazil. Due to its historical and environmental relevance, the aim of this study was to evaluate the effects of oestrogenic endocrine disruptors on the reproduction of the lambari Astyanax rivularis, a small-sized species found in headwaters of the São Francisco River basin. Quarterly field samplings were carried out during a reproductive cycle in three streams of the upper Velhas River: S1 (reference site) and S2 and S3 (sites contaminated by untreated sewage). The main oestrogenic compounds were evaluated in water using HPLC/MS. Molecular, histological and reproductive biomarkers were assessed in liver and gonad. The results showed higher average concentrations of oestradiol (>200ng/l) in S2 and S3, oestrone (>250ng/l) in S2 as well as oestriol (>200ng/l), bisphenol A (>190ng/l), and nonylphenol (>600ng/l) in S3 compared to S1 (<70ng/l for all compounds). In S2 and S3, there was an increase in the proportion of females, higher ELISA levels of vitellogenin (Vtg) and proteins of the zona radiata (Zrp) in liver males. Insulin-like growth factor (IGF-I) levels were lower in S2 males, which also had a smaller body size, a smaller seminiferous tubule diameter, a higher proportion of spermatogonia, and lower proportion of spermatozoa in relation to S1. Histopathological analyses detected an increase in yolk deficient oocytes and over-ripening in the contaminated sites, and these alterations were associated to a reduction of hepatic Vtg levels and a delay in spawning, respectively. Intersex specimens with perinucleolar follicles in a multifocal distribution in the testis were detected in S2 and S3. These results indicate that chronic exposure to oestrogenic compounds induced endocrine disruption that may affect wild populations of A. rivularis in the Velhas River.

  10. Channel morphology and patterns of bedload transport in fluvial, formerly-glaciated, forested headwater streams of the Columbia Mountains, Canada

    NASA Astrophysics Data System (ADS)

    Green, Kim; Brardinoni, Francesco; Alila, Younes

    2013-04-01

    This study examines channel-reach morphology and bedload transport dynamics in relation to landscape structure and snowmelt hydrology in Cotton and Elk Creek, two headwater streams of the southern Columbia Mountains, Canada. Data collection is based on field surveys and GIS analysis in conjunction with a nested monitoring network of water discharge and bed load transfer. The nested monitoring network is designed to examine the effects of channel bed texture, and the influence of free-formed (i.e., boulder cascades, step pools, and riffle pools) and forced-alluvial morphologies (i.e., forced step pools) on bedload entrainment and transport. The landscape is characterized by subdued glaciated topography in which sediment is primarily supplied by bank failures and fluvial transfer dominates the channelized sediment cascade. The spatial distribution of channel types is mainly controlled by glacially imposed local slope together with availability of wood and glacigenic materials. Interestingly, downstream hydraulic geometry as well as downstream patterns of the coarse channel bed fraction and stream power are all insensitive to systematic changes of local slope along the typically stepped longitudinal profiles. An indication that the study alluvial systems are adjusted to the contemporary hydrologic and sedimentary regimes, and as such through post-LGM times have been able to compensate for the glacially-imposed boundary conditions. Stepwise multiple regression indicates that annual bedload yield is chiefly controlled by the number of peak events over threshold discharge. During such high flows, repeated destabilization of channel bed armouring and re-mobilization of sediment stored behind logjams can ensure sediment supply for bedload transport across the entire snowmelt season. In particular, channel morphology affects distinctively the variability of bed load response to hydrologic forcing. The observed spatial variability in annual bedload yield appears to correlate

  11. Oxygen isotopic composition of bulk carbonates in recent sediments from Lake Kuhai (NW China) and implications for hydroclimatic changes in headwater areas of the Yellow River on the northeastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Li, Xiangzhong; Zhou, Xin; Liu, Weiguo; Fan, Guoqing; Cheng, Peng; Xu, Liming

    2017-02-01

    The water resource issue is one of the most significant problems in the Yellow River basin, and has received much attention from the public and government because of the dramatically decreased Yellow River streamflow in the last several years. In this study, oxygen isotopic compositions of bulk carbonates from Lake Kuhai in the headwaters of the Yellow River were evaluated as an indirect proxy of past Yellow River streamflow in order to place the recent flow reduction in a long-term context. The results indicated that δ18O values of bulk carbonates from core KHC14-1 generally vary with changes in the Yellow River streamflows related to the precipitation/evaporation (temperature) ratio above the Tangnaihai hydrological station over the past 50 years. In general, the Yellow River streamflow in the headwaters area continued to decrease from the early 1980s to the late 1990s because of decreased precipitation and increased temperature. Then, the streamflow increased with enhancing precipitation over the last two decades. In addition, δ18O values of bulk carbonates in the Lake Kuhai core roughly correlate with the streamflows of the upper reaches of the Yellow River recorded by tree ring width over the past 800 years. The enriched δ18OBC values showed that the precipitation/evaporation (P/E) ratio or streamflow was very low and the climate might be very dry in the middle of the 1400s CE in the headwaters of the Yellow River over the past 800 years. Our results suggested that changes in the P/E ratio or streamflow of the upper reaches of the Yellow River were dominated by variations in Indian Summer Monsoon precipitation over a long time scale, consistent with other records from the northeastern Tibetan Plateau.

  12. Spatially intensive sampling by electrofishing for assessing longitudinal discontinuities in fish distribution in a headwater stream

    USGS Publications Warehouse

    Le Pichon, Céline; Tales, Évelyne; Belliard, Jérôme; Torgersen, Christian E.

    2017-01-01

    Spatially intensive sampling by electrofishing is proposed as a method for quantifying spatial variation in fish assemblages at multiple scales along extensive stream sections in headwater catchments. We used this method to sample fish species at 10-m2 points spaced every 20 m throughout 5 km of a headwater stream in France. The spatially intensive sampling design provided information at a spatial resolution and extent that enabled exploration of spatial heterogeneity in fish assemblage structure and aquatic habitat at multiple scales with empirical variograms and wavelet analysis. These analyses were effective for detecting scales of periodicity, trends, and discontinuities in the distribution of species in relation to tributary junctions and obstacles to fish movement. This approach to sampling riverine fishes may be useful in fisheries research and management for evaluating stream fish responses to natural and altered habitats and for identifying sites for potential restoration.

  13. Patterns and structures of land use change in the Three Rivers Headwaters Region of China.

    PubMed

    Yang, Jingbiao; Wang, Yi Chen; Guo, Luo; Xue, Dayuan

    2015-01-01

    Located in Qinghai Province of China, the Three Rivers Headwaters Region is the source region of the Yangtze, Yellow and Lantsang Rivers, and plays an important role in biodiversity conservation and regulating water supply. Despite many efforts on land use change in Qinghai, knowledge of the spatial variation of land use change is still lacking. This study examines the patterns of land use change across various watersheds, prefectures and the temple surroundings. Remote sensing images of 1987, 1997 and 2007 were analyzed to derive land use distributions; patterns and structures of the landscape were then quantified with landscape metrics. The results illustrated that the Yangtze River headwater region had more diverse and more evenly distributed landscape, while the Lantsang and the Yellow headwater regions showed a decline in landscape diversity. Comparison of the land use patterns of four prefectures revealed that Yushu Prefecture experienced an increase in landscape diversity from 1987 to 2007 while the land use patches in Guoluo Prefecture exhibited more aggregated patterns than other prefectures. Analysis of the spatial variations of land use change in the temple surroundings illustrated that 19.7% and 35.9% of the temples in Guoluo and Yushu Prefectures, respectively, encountered land use change for their immediate areas within 2 km. Comparison of the surroundings of temples and human settlements found that land use change was not evenly distributed, and that greater land use change had occurred for the surroundings of human settlements. Such findings provided insights into the spatial variation of land use change in the Three Rivers Headwaters Region.

  14. Forested headwaters mitigate pesticide effects on macroinvertebrate communities in streams: Mechanisms and quantification.

    PubMed

    Orlinskiy, Polina; Münze, Ronald; Beketov, Mikhail; Gunold, Roman; Paschke, Albrecht; Knillmann, Saskia; Liess, Matthias

    2015-08-15

    Pesticides impact invertebrate communities in freshwater ecosystems, leading to the loss of biodiversity and ecosystem functions. One approach to reduce such effects is to maintain uncontaminated stream reaches that can foster recovery of the impacted populations. We assessed the potential of uncontaminated forested headwaters to mitigate pesticide impact on the downstream macroinvertebrate communities in 37 streams, using the SPEARpesticides index. Pesticide contamination was measured with runoff-triggered techniques and Chemcatcher® passive samplers. The data originated from 3 field studies conducted between 1998 and 2011. The proportion of vulnerable species decreased significantly after pesticide exposure even at low toxicity levels (-4headwaters was not associated with reduced pesticide exposure 3 km downstream and did not reduce the loss of vulnerable taxa after exposure. Nevertheless, forested headwaters were associated with the absence of long-term pesticide effects on the macroinvertebrate community composition. We conclude that although pesticides can cause the loss of vulnerable aquatic invertebrates even at low toxicity levels, forested headwaters enhance the recovery of vulnerable species in agricultural landscapes.

  15. Spatial Variations in Carbon Storage along Headwater Fluvial Networks with Differing Valley Geometry

    NASA Astrophysics Data System (ADS)

    Wohl, E. E.; Dwire, K. A.; Polvi, L. E.; Sutfin, N. A.; Bazan, R. A.

    2011-12-01

    We distinguish multiple valley types along headwater fluvial networks in the Colorado Front Range based on valley geometry (downstream gradient and valley-bottom width relative to active channel width) and the presence of biotic drivers (beaver dams or channel-spanning logjams associated with old-growth forest) capable of creating a multi-thread channel pattern. Valley type influences storage of fine sediment, organic matter, and carbon. Deep, narrow valleys have limited storage potential, whereas wide, shallow valleys with multi-thread channels have substantial storage potential. Multi-thread channels only occur in the presence of a biotic driver. Given the importance of headwater streams in the global carbon cycle, it becomes important to understand the spatial distribution and magnitude of carbon storage along these streams, as well as the processes governing patterns of storage. We compare carbon stored in three reservoirs: riparian vegetation (live, dead, and litter), instream and floodplain large wood, and floodplain soils for 100-m-long valley segments in seven different valley types. The valley types are (i) laterally confined valleys in old-growth forest, (ii) partly confined valleys in old-growth forest, (iii) laterally unconfined valleys with multi-thread channels in old-growth forest, (iv) laterally unconfined valleys with single-thread channels in old-growth forest, (v) laterally confined valleys in younger forest, (vi) recently abandoned beaver-meadow complexes with multi-thread channels and willow thickets, and (vii) longer abandoned beaver-meadow complexes with single-thread channels and very limited woody vegetation. Preliminary results suggest that, although multi-thread channel segments driven by beavers or logjams cover less than 25 percent of the total length of headwater river networks in the study area, they account for more than three-quarters of the carbon stored along the river network. Historical loss of beavers and old-growth forest has

  16. Reach-scale geomorphic differences between headwater streams draining mountaintop mined and unmined catchments

    NASA Astrophysics Data System (ADS)

    Jaeger, Kristin L.

    2015-05-01

    Mountaintop surface mining (MTM) is a controversial coal extraction method commonly practiced in the central and southern Appalachian Mountains, USA, that drastically reengineers previously steep, forested landscapes and alters sediment and water delivery processes to and along headwater channels draining mined areas. Although sediment delivery and hydrologic response from MTM operations remain highly variable and poorly resolved, the inherent close coupling between hillslopes and headwater channels is expected to result in geomorphic differences in stream channels draining MTM landscapes relative to unmined landscapes. Dedicated geomorphic studies are severely lacking in comparison to extensive research on water quality impacts of MTM. This study reports moderate geomorphic differences between headwater (catchment area <~ 6 km2) stream channels draining MTM and unmined catchments in tributaries of the Mud River in southern West Virginia. Univariate and multivariate analyses indicate that MTM streams are characterized by deeper maximum channel depths, smaller width-to-depth ratios, increased bedrock exposure along the streambed, and increased frequency of very fine silt and sand deposition relative to channels draining unmined catchments. Geomorphic differences are most pronounced for streams draining the smallest catchment areas (< 3.5 km2). Collectively, geomorphic differences provide evidence for relatively rapid channel adjustment of accelerated bedrock incision attributed to potential increased hydraulic driving forces and altered sediment regimes in MTM channels, notably sustained delivery of very fine sediment and potentially reduced coarse sediment delivery. More rapid delivery and transfer of water in addition to excess delivery of very fine sediments to and through headwater channels will have consequences to flooding and water quality in the short term and landscape evolution processes over longer time scales. Given the extent of MTM operations in this

  17. Effect of riparian vegetation on diatom assemblages in headwater streams under different land uses.

    PubMed

    Hlúbiková, Daša; Novais, Maria Helena; Dohet, Alain; Hoffmann, Lucien; Ector, Luc

    2014-03-15

    Differences in the structure of diatom assemblages in headwaters with contrasting shading conditions and different land use in the buffer zone and upper catchment were studied in order to evaluate the influence of the lack of riparian vegetation on the biofilm. The objective was to ascertain whether a riparian buffer can mitigate the negative influence of human induced disturbance and pollution on diatom assemblages in headwaters. Four streams were selected in order to maximize the differences in the land cover and minimize other environmental gradients. Multivariate statistics, different comparative and permutation tests and correlations were applied to compare the diatom assemblages, the Specific Polluosensitivity Index (IPS) and the diatom ecological guilds (low profile, high profile and motile) among the sites studied and to evaluate their responses to disturbances. The analysis showed that low profile diatoms typically dominated in forested headwaters with limited resources, whilst assemblages at impacted sites showed a wider range of growth forms. In unimpacted streams, the diatom assemblages were influenced by temperature, pH, conductivity and calcium, as usually reported for oligotrophic streams with high natural disturbance due to fast current and shading. In both shaded and unshaded impacted streams, the importance of nutrients and land use disturbance, especially urbanization, prevailed. This trend was also reflected by the IPS index that showed consistently lower values at impacted sites, correlating most significantly with nutrients. The diatom species composition as well as diatom guilds at impacted sites were similar, regardless of the presence or absence of riparian vegetation, and were significantly influenced by seasonal changes. Our results indicate that diatoms react sensitively to alterations of the water environment in headwaters, induced by anthropogenic activities, and these impacts are not buffered by an intact riparian zone. Diatoms

  18. Mapping Water Resources, Allocation and Consumption in the Mills River Basin

    NASA Astrophysics Data System (ADS)

    Hodes, J.; Jeuland, M. A.; Barros, A. P.

    2014-12-01

    Mountain basins and the headwaters of river basins along the foothills of major mountain ranges are undergoing rapid environmental change due to urban development, land acquisition by investors, population increase, and climate change. Classical water infrastructure in these regions is primarily designed to meet human water demand associated with agriculture, tourism, and economic development. Often overlooked and ignored is the fundamental interdependence of human water demand, ecosystem water demand, water rights and allocation, and water supply. A truly sustainable system for water resources takes into account ecosystem demand along with human infrastructure and economic demand, as well as the feedbacks that exist between them. Allocation policies need to take into account basin resilience that is the amount of stress the system can handle under varying future scenarios. Changes in stress on the system can be anthropogenic in the form of population increase, land use change, economic development, or may be natural in the form of climate change and decrease in water supply due to changes in precipitation. Mapping the water rights, supply, and demands within the basin can help determine the resiliency and sustainability of the basin. Here, we present a coupled natural human system project based in the French Broad River Basin, in the Southern Appalachians. In the first phase of the project, we are developing and implementing a coupled hydro-economics modeling framework in the Mills River Basin (MRB), a tributary of the French Broad. The Mills River Basin was selected as the core basin for implementing a sustainable system of water allocation that is adaptive and reflects the interdependence of water dependent sectors. The headwaters of the Mills River are in the foothills of the Appalachians, and are currently under substantial land use land cover (LULC) change pressure for agricultural purposes. In this regard, the MRB is representative of similar headwater

  19. Similarities and Differences Between Headwater Streams in the Mountains and Piedmont of North Carolina

    NASA Astrophysics Data System (ADS)

    Eaton, L.

    2005-05-01

    Biological sampling has been underway in headwater streams in the North Carolina Piedmont for two years and in Mountain headwater streams for one. Streams in the mountains usually started at springs, whereas most piedmont streams are fed by surface water runoff. Watersheds above springs, both mountain and piedmont, were smaller (mean 4 acres) than surface water streams in both regions (mean 19 acres). While taxa richness at perennial mountain headwater sites was similar (mean 38 taxa/sample) to piedmont perennial sites (mean 35), macroinvertebrate abundance in the mountains (mean 540 organisms/sample) was nearly double the sample abundance in the piedmont (mean 295). In both ecoregions winter/spring peaks in taxa richness and abundance were observed. Intermittent segments in the mountains were rare, but occurred as wet weather springs, while in the piedmont, intermittent segments were stream channels above perennial reaches. In both types, taxa richness and abundance were very low when the channel was dry, but were only slightly below levels found in perennial segments when wet. There were few species confined to intermittent reaches. Most taxa collected in intermittent reaches were also found downstream in perennial reaches, however some groups (e.g. mayflies, caddisflies, odonates, megaloptera) were rarely found in intermittent segments.

  20. A Spatially Explicit Approach for Evaluating Relationships among Coastal Cutthroat, Habitat, and Disturbance in Headwater Streams

    NASA Astrophysics Data System (ADS)

    Gresswell, R. E.; Bateman, D. S.; Torgersen, C. E.; Guy, T. J.; Hendricks, S. R.; Wofford, J. E.

    2005-05-01

    Headwater stream systems are complex networks that form a physicochemical template governing the persistence of aquatic species such as coastal cutthroat trout. Individual portions of the network can function as conduits or receptacles for sediments, wood, and nutrients from terrestrial areas. Temporal and spatial changes in the delivery of these constituents can substantially alter the habitat template and its ability to support this native fish. Our study of 40 mid-sized watersheds (500 - 1,500 ha) in western Oregon is providing new insights into the factors affecting the distribution of coastal cutthroat trout within, and among, headwater stream networks. For example, data suggest that coastal cutthroat trout move throughout the accessible portions of headwater streams for reproductive, feeding, and refuge purposes. Fish congregate in these areas and form local populations that may exhibit unique phenotypic and genetic attributes. At times, coastal cutthroat trout move into larger downstream portions of the network where they may contribute to the persistence and genetic character of anadromous or local potamodromous assemblages. Variation in distribution patterns among watersheds reflects diverse environments and selective factors, such as geology, geomorphology, climate, and land-management history. Our research findings suggest that human activities that impede movement among suitable habitat patches can have lasting consequences for local assemblages of coastal cutthroat trout and may ultimately affect persistence.

  1. Large carbon dioxide fluxes from headwater boreal and sub-boreal streams.

    PubMed

    Venkiteswaran, Jason J; Schiff, Sherry L; Wallin, Marcus B

    2014-01-01

    Half of the world's forest is in boreal and sub-boreal ecozones, containing large carbon stores and fluxes. Carbon lost from headwater streams in these forests is underestimated. We apply a simple stable carbon isotope idea for quantifying the CO2 loss from these small streams; it is based only on in-stream samples and integrates over a significant distance upstream. We demonstrate that conventional methods of determining CO2 loss from streams necessarily underestimate the CO2 loss with results from two catchments. Dissolved carbon export from headwater catchments is similar to CO2 loss from stream surfaces. Most of the CO2 originating in high CO2 groundwaters has been lost before typical in-stream sampling occurs. In the Harp Lake catchment in Canada, headwater streams account for 10% of catchment net CO2 uptake. In the Krycklan catchment in Sweden, this more than doubles the CO2 loss from the catchment. Thus, even when corrected for aquatic CO2 loss measured by conventional methods, boreal and sub-boreal forest carbon budgets currently overestimate carbon sequestration on the landscape.

  2. Headwater streams and forest management: does ecoregional context influence logging effects on benthic communities?

    USGS Publications Warehouse

    Medhurst, R. Bruce; Wipfli, Mark S.; Binckley, Chris; Polivka, Karl; Hessburg, Paul F.; Salter, R. Brion

    2010-01-01

    Effects of forest management on stream communities have been widely documented, but the role that climate plays in the disturbance outcomes is not understood. In order to determine whether the effect of disturbance from forest management on headwater stream communities varies by climate, we evaluated benthic macroinvertebrate communities in 24 headwater streams that differed in forest management (logged-roaded vs. unlogged-unroaded, hereafter logged and unlogged) within two ecological sub-regions (wet versus dry) within the eastern Cascade Range, Washington, USA. In both ecoregions, total macroinvertebrate density was highest at logged sites (P = 0.001) with gathering-collectors and shredders dominating. Total taxonomic richness and diversity did not differ between ecoregions or forest management types. Shredder densities were positively correlated with total deciduous and Sitka alder (Alnus sinuata) riparian cover. Further, differences in shredder density between logged and unlogged sites were greater in the wet ecoregion (logging × ecoregion interaction; P = 0.006) suggesting that differences in post-logging forest succession between ecoregions were responsible for differences in shredder abundance. Headwater stream benthic community structure was influenced by logging and regional differences in climate. Future development of ecoregional classification models at the subbasin scale, and use of functional metrics in addition to structural metrics, may allow for more accurate assessments of anthropogenic disturbances in mountainous regions where mosaics of localized differences in climate are common.

  3. Soil water flow is a source of the plant pathogen Pseudomonas syringae in subalpine headwaters.

    PubMed

    Monteil, Caroline L; Lafolie, François; Laurent, Jimmy; Clement, Jean-Christophe; Simler, Roland; Travi, Yves; Morris, Cindy E

    2014-07-01

    The airborne plant pathogenic bacterium Pseudomonas syringae is ubiquitous in headwaters, snowpack and precipitation where its populations are genetically and phenotypically diverse. Here, we assessed its population dynamics during snowmelt in headwaters of the French Alps. We revealed a continuous and significant transport of P.syringae by these waters in which the population density is correlated with water chemistry. Via in situ observations and laboratory experiments, we validated that P.syringae is effectively transported with the snow melt and rain water infiltrating through the soil of subalpine grasslands, leading to the same range of concentrations as measured in headwaters (10(2) -10(5) CFU l(-1) ). A population structure analysis confirmed the relatedness between populations in percolated water and those above the ground (i.e. rain, leaf litter and snowpack). However, the transport study in porous media suggested that water percolation could have different efficiencies for different strains of P.syringae. Finally, leaching of soil cores incubated for up to 4 months at 8°C showed that indigenous populations of P.syringae were able to survive in subalpine soil under cold temperature. This study brings to light the underestimated role of hydrological processes involved in the long distance dissemination of P.syringae.

  4. The role of ground water in generating streamflow in headwater areas and in maintaining base flow

    USGS Publications Warehouse

    Winter, T.C.

    2007-01-01

    The volume and sustainability of streamflow from headwaters to downstream reaches commonly depend on contributions from ground water. Streams that begin in extensive aquifers generally have a stable point of origin and substantial discharge in their headwaters. In contrast, streams that begin as discharge from rocks or sediments having low permeability have a point of origin that moves up and down the channel seasonally, have small incipient discharge, and commonly go dry. Nearly all streams need to have some contribution from ground water in order to provide reliable habitat for aquatic organisms. Natural processes and human activities can have a substantial effect on the flow of streams between their headwaters and downstream reaches. Streams lose water to ground water when and where their head is higher than the contiguous water table. Although very common in arid regions, loss of stream water to ground water also is relatively common in humid regions. Evaporation, as well as transpiration from riparian vegetation, causing ground-water levels to decline also can cause loss of stream water. Human withdrawal of ground water commonly causes streamflow to decline, and in some regions has caused streams to cease flowing. ?? 2007 American Water Resources Association.

  5. Interaction of esker groundwater with headwater lakes and streams

    NASA Astrophysics Data System (ADS)

    Ala-aho, Pertti; Rossi, Pekka M.; Kløve, Bjørn

    2013-09-01

    Groundwater-surface water interactions were studied in a Finnish esker aquifer system where some lakes suffer from periodic water level decline and others from eutrophication. Natural tracers (Ca2+, SiO2 and PO43-) were used on the aquifer scale and seepage meter measurements and water level recordings on the single lake scale to better understand the complex interactions between groundwater, lakes and streams in the area. The natural tracers showed that lakes located in lower landscape positions and connected with streams were richer in tracer concentrations and that their water chemistry resembled that of the groundwater. On the other hand, closed basin lakes located at higher altitudes were nutrient-poor seepage lakes with some groundwater through flow. The data suggests that the subsurface acts as a phosphate source for the surface water bodies and the nutrient rich groundwater inseepage dictates the trophic status of the lakes in the area. The seepage meter measurements verified a strong interaction between groundwater and surface water and revealed spatial distribution of lake seepage and a temporal co-variation in lake seepage rates. A statistical analysis of seepage meter and water level observation time series were useful to show groundwater flow regimes controlling lake seepage. Using the natural tracer analysis and seepage meter measurements, we developed a novel conceptual model for the study site where the differences in lake trophic state and water table behavior were explained by assigning lakes to local and regional groundwater flow regimes. The obtained results provide new knowledge on using natural tracers in complex glacial aquifer systems and can be used in integrated groundwater-surface water management.

  6. Water-quality investigation, Upper Santa Clara River Basin, California

    USGS Publications Warehouse

    Bowers, James C.; Irwin, G.A.

    1978-01-01

    Water-quality data are summarized for the upper Santa Clara River basin, California from studies beginning August 1974 through June 1976 and during past monitoring programs. Data were collected for nitrogen, phosphorus, total organic carbon, trace elements, detergents, and pesticide compounds. Because of the limited number of samples, the data are only an estimate of conditions that existed in the basin. Sampling was designed so that samples from each site would represent seasonal variations in discharge. Most constituents were fairly low in concentration near the headwaters at Ravenna and higher below the urban and agricultural area near Saugus. Mean specific conductance in the river ranged from 745 micromhos per centimeter at 25 deg C below the headwaters near Lang to 2,640 micromhos at the Los Angeles-Ventura County line. Results also indicate that discharge was not the single factor controlling the concentration variance for most constituents. Regression analyses indicated a high correlation between specific conductance and most major inorganic chemical constituents, and between specific conductance and discharge. (Woodard-USGS)

  7. BASINS Publications

    EPA Pesticide Factsheets

    Although BASINS has been in use for the past 10 years, there has been limited modeling guidance on its applications for complex environmental problems, such as modeling impacts of hydro modification on water quantity and quality.

  8. Comparison of organic matter composition in agricultural versus forest affected headwaters with special emphasis on organic nitrogen.

    PubMed

    Heinz, Marlen; Graeber, Daniel; Zak, Dominik; Zwirnmann, Elke; Gelbrecht, Joerg; Pusch, Martin T

    2015-02-17

    Agricultural management practices promote organic matter (OM) turnover and thus alter both the processing of dissolved organic matter (DOM) in soils and presumably also the export of DOM to headwater streams, which intimately connect the terrestrial with the aquatic environment. Size-exclusion chromatography, in combination with absorbance and emission matrix fluorometry, was applied to assess how agricultural land use alters the amount and composition of DOM, as well as dissolved organic nitrogen (DON) forms in headwater streams, including temporal variations, in a temperate region of NE Germany. By comparing six agriculturally and six forest-impacted headwater streams, we demonstrated that agriculture promotes increased DOC and DON concentrations, entailing an even more pronounced effect on DON. The major part of DOC and DON in agricultural and forest reference streams is exported in the form of humic-like material with high molecular weight, which indicates terrestrial, i.e., allochthonous sources. As an obvious difference in agricultural streams, the contribution of DOC and particularly DON occurring in the form of nonhumic high-molecular-weight, presumably proteinous material is clearly elevated. Altogether, DOM in agricultural headwaters is mainly complex-soil-derived and aromatic material with a low C:N ratio, which is more microbial processed than its counterpart from forest reference catchments. Our results emphasize the importance of agricultural land use on DOM loss from soils and identify agricultural soils as important DOC and particularly DON sources to headwater streams.

  9. Terrace Formation in the Upper Headwater Region of the Mattole River Watershed Across the Mendocino Triple Junction, Northwest California

    NASA Astrophysics Data System (ADS)

    Robinson, M.; Flanagan, S., II; Hemphill-Haley, M. A.

    2015-12-01

    The Mattole River, in northwestern California, is located in a tectonically active and geologically complex area, the Mendocino triple junction (MTJ), where the North American, Pacific and Gorda plates meet. The Mattole River does not follow the classic river "concave-up" profile. Instead, the river headwaters have wide valleys of low gradient fill, cut and strath terraces with deeply incised active channels. In fact, the river has a "convex-up" profile with a low gradient headwater leading to a higher gradient midcourse. Terrace formation in the upper headwater region of the Mattole River records times of disequilibrium of channel profile and incision as the river responds to changes that are, in large part, due to the passage of the northwardly migrating, thermally buoyant MTJ. In order to investigate the distribution and relative ages of terraces, detailed surveys of terrace surfaces and bedrock strath positions were conducted along four headwater tributaries: Thompson Creek, Baker Creek, Lost River and Ancestor Creek. Additionally, across the terraces, hand borings were excavated to bedrock to provide a three dimensional image of terrace thickness. Terrace morphology and stratigraphy provide information on terrace forming mechanisms and timing. This study includes high-resolution geomorphic data regarding the relation of Mattole headwater terraces to the MTJ, as well as provides more temporal information about the fluvial system's response to the ongoing northward migration of the MTJ.

  10. Parana basin

    SciTech Connect

    Zalan, P.V.; Wolff, S.; Conceicao, J.C.J.; Vieira, I.S.; Astolfi, M.A.; Appi, V.T.; Zanotto, O.; Neto, E.V.S.; Cerqueira, J.R.

    1987-05-01

    The Parana basin is a large intracratonic basin in South America, developed entirely on continental crust and filled with sedimentary and volcanic rocks ranging in age from Silurian to Cretaceous. It occupies the southern portion of Brazil (1,100,000 km/sup 2/ or 425,000 mi/sup 2/) and the eastern half of Paraguay (100,000 km/sup 2/ or 39,000 mi/sup 2/); its extension into Argentina and Uruguay is known as the Chaco-Parana basin. Five major depositional sequences (Silurian, Devonian, Permo-Carboniferous, Triassic, Juro-Cretaceous) constitute the stratigraphic framework of the basin. The first four are predominantly siliciclastic in nature, and the fifth contains the most voluminous basaltic lava flows of the planet. Maximum thicknesses are in the order of 6000 m (19,646 ft). The sequences are separated by basin wide unconformities related in the Paleozoic to Andean orogenic events and in the Mesozoic to the continental breakup and sea floor spreading between South America and Africa. The structural framework of the Parana basin consists of a remarkable pattern of criss-crossing linear features (faults, fault zones, arches) clustered into three major groups (N45/sup 0/-65/sup 0/W, N50/sup 0/-70/sup 0/E, E-W). The northwest- and northeast-trending faults are long-lived tectonic elements inherited from the Precambrian basement whose recurrent activity throughout the Phanerozoic strongly influenced sedimentation, facies distribution, and development of structures in the basin. Thermomechanical analyses indicate three main phases of subsidence (Silurian-Devonian, late Carboniferous-Permian, Late Jurassic-Early Cretaceous) and low geothermal gradients until the beginning of the Late Jurassic Permian oil-prone source rocks attained maturation due to extra heat originated from Juro-Cretaceous igneous intrusions. The third phase of subsidence also coincided with strong tectonic reactivation and creation of a third structural trend (east-west).

  11. Potential Seasonal Terrestrial Water Storage Monitoring from GPS Vertical Displacements: A Case Study in the Lower Three-Rivers Headwater Region, China

    PubMed Central

    Zhang, Bao; Yao, Yibin; Fok, Hok Sum; Hu, Yufeng; Chen, Qiang

    2016-01-01

    This study uses the observed vertical displacements of Global Positioning System (GPS) time series obtained from the Crustal Movement Observation Network of China (CMONOC) with careful pre- and post-processing to estimate the seasonal crustal deformation in response to the hydrological loading in lower three-rivers headwater region of southwest China, followed by inferring the annual EWH changes through geodetic inversion methods. The Helmert Variance Component Estimation (HVCE) and the Minimum Mean Square Error (MMSE) criterion were successfully employed. The GPS inferred EWH changes agree well qualitatively with the Gravity Recovery and Climate Experiment (GRACE)-inferred and the Global Land Data Assimilation System (GLDAS)-inferred EWH changes, with a discrepancy of 3.2–3.9 cm and 4.8–5.2 cm, respectively. In the research areas, the EWH changes in the Lancang basin is larger than in the other regions, with a maximum of 21.8–24.7 cm and a minimum of 3.1–6.9 cm. PMID:27657064

  12. Potential Seasonal Terrestrial Water Storage Monitoring from GPS Vertical Displacements: A Case Study in the Lower Three-Rivers Headwater Region, China.

    PubMed

    Zhang, Bao; Yao, Yibin; Fok, Hok Sum; Hu, Yufeng; Chen, Qiang

    2016-09-19

    This study uses the observed vertical displacements of Global Positioning System (GPS) time series obtained from the Crustal Movement Observation Network of China (CMONOC) with careful pre- and post-processing to estimate the seasonal crustal deformation in response to the hydrological loading in lower three-rivers headwater region of southwest China, followed by inferring the annual EWH changes through geodetic inversion methods. The Helmert Variance Component Estimation (HVCE) and the Minimum Mean Square Error (MMSE) criterion were successfully employed. The GPS inferred EWH changes agree well qualitatively with the Gravity Recovery and Climate Experiment (GRACE)-inferred and the Global Land Data Assimilation System (GLDAS)-inferred EWH changes, with a discrepancy of 3.2-3.9 cm and 4.8-5.2 cm, respectively. In the research areas, the EWH changes in the Lancang basin is larger than in the other regions, with a maximum of 21.8-24.7 cm and a minimum of 3.1-6.9 cm.

  13. Sediment transport in headwaters of a volcanic catchment—Kamchatka Peninsula case study

    NASA Astrophysics Data System (ADS)

    Chalov, Sergey R.; Tsyplenkov, Anatolii S.; Pietron, Jan; Chalova, Aleksandra S.; Shkolnyi, Danila I.; Jarsjö, Jerker; Maerker, Michael

    2017-01-01

    Due to specific environmental conditions, headwater catchments located on volcanic slopes and valleys are characterized by distinctive hydrology and sediment transport patterns. However, lack of sufficient monitoring causes that the governing processes and patterns in these areas are rarely well understood. In this study, spatiotemporal water discharge and sediment transport from upstream sources was investigated in one of the numerous headwater catchments located in the lahar valleys of the Kamchatka Peninsula Sukhaya Elizovskaya River near Avachinskii and Koryakskii volcanoes. Three different subcatchments and corresponding channel types (wandering rivers within lahar valleys, mountain rivers within volcanic slopes and rivers within submountain terrains) were identified in the studied area. Our measurements from different periods of observations between years 2012-2014 showed that the studied catchment was characterized by extreme diurnal fluctuation of water discharges and sediment loads that were influenced by snowmelt patterns and high infiltration rates of the easily erodible lahar deposits. The highest recorded sediment loads were up to 9•104 mg/L which was related to an increase of two orders of magnitude within a one day of observations. Additionally, to get a quantitative estimate of the spatial distribution of the eroded material in the volcanic substrates we applied an empirical soil erosion and sediment yield model-modified universal soil loss equation (MUSLE). The modeling results showed that even if the applications of the universal erosion model to different non-agricultural areas (e.g., volcanic catchments) can lead to irrelevant results, the MUSLE model delivered might be acceptable for non-lahar areas of the studied volcanic catchment. Overall the results of our study increase our understanding of the hydrology and associated sediment transport for prediction of risk management within headwater volcanic catchments.

  14. The Impact of Enhanced Summer Thaw, Hillslope Disturbances, and Late Season Rainfall on Solute Fluxes from High Arctic Headwater Catchments

    NASA Astrophysics Data System (ADS)

    Lafreniere, M. J.; Lamoureux, S. F.

    2011-12-01

    This study examines variations in the composition and total seasonal fluxes of dissolved solutes in several small High Arctic headwater catchments at the Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, Nunavut (74°54'N, 109°35'W) over multiple snowmelt seasons (2007, 2008, 2009) with contrasting climate and permafrost active layer conditions. Climate warming in the High Arctic will affect a number processes that will alter the hydrological and biogeochemical exports from the landscape. Climate change is projected to alter precipitation regimes, resulting in increases in both winter and summer precipitation in the High Arctic, thereby altering hydrological regimes. Warming will result in thickening of the seasonal active layer, which will alter hydrological flow paths and water and solute sources. Additionally, active layer thickening and permafrost warming is also project to enhance the development of thermokarst features, including hillslope disturbances, such as active layer detachment slides and retrogressive thaw slumps. This research compares the flux of inorganic and organic solutes emanating from a group of catchments that were subject to a range hillslope disturbances, or active layer detachment slides (ALDs), at the end of summer 2007. One of the catchments, Goose, was not subject to any disturbance, while active layer slides covered between 6% and 46% of the catchment area in the disturbed catchments. It was hypothesised that solute fluxes would increase primarily with increasing extent and degree of disturbance. This however, was not observed. Rather, comparing five sites with varying degrees of disturbance in 2009 illustrates that on a specific area and specific volume of runoff basis, solute fluxes were unrelated to disturbance extent. Comparing two catchments that were monitored from 2007 (pre-disturbance) through to 2009 (2 yrs post disturbance), shows that both catchments were subject to solute flux increases, however the solute

  15. Evaluation of agricultural best-management practices in the Conestoga River headwaters, Pennsylvania; effects of nutrient management on water quality in the Little Conestoga Creek headwaters, 1983-89

    USGS Publications Warehouse

    Koerkle, E.H.; Fishel, D.K.; Brown, M.J.; Kostelnik, K.M.

    1996-01-01

    Water quality in the headwaters of the Little Conestoga Creek, Lancaster County, Pa., was investigated from April 1986 through September 1989 to determine possible effects of agricultural nutrient management on water quality. Nutrient management, an agricultural Best-Management Practice, was promoted in the 5.8-square-mile watershed by the U.S. Department of Agriculture Rural Clean Water Program. Nonpoint-source- agricultural contamination was evident in surface water and ground water in the watershed; the greatest contamination was in areas underlain by carbonate rock and with intensive row-crop and animal production. Initial implementation of nutrient management covered about 30 percent of applicable land and was concentrated in the Nutrient-Management Subbasin. By 1989, nutrient management covered about 45 percent of the entire Small Watershed, about 85 percent of the Nutrient- Management Subbasin, and less than 10 percent of the Nonnutrient-Management Subbasin. The number of farms implementing nutrient management increased from 14 in 1986 to 25 by 1989. Nutrient applications to cropland in the Nutrient- Management Subbasin decreased by an average of 35 percent after implementation. Comparison of base- flow surface-water quality from before and after implementation suggests that nutrient management was effective in slowing or reversing increases in concentrations of dissolved nitrate plus nitrite in the Nutrient-Management Subbasin. Although not statistically significant, the Mann-Whitney step-trend coefficient for the Nutrient-Management Subbasin was 0.8 milligram per liter, whereas trend coefficients for the Nonnutrient-Management Subbasin and the Small Watershed were 0.4 and 1.4 milligrams per liter, respectively, for the period of study. Analysis of covariance comparison of concurrent concentrations from the two sub- basins showed a significant decrease in concen- trations from the Nutrient-Management Subbasin compared to the Nonnutrient-Management Subbasin

  16. Elevated aluminium concentration in acidified headwater streams lowers aquatic hyphomycete diversity and impairs leaf-litter breakdown.

    PubMed

    Baudoin, J M; Guérold, F; Felten, V; Chauvet, E; Wagner, P; Rousselle, P

    2008-08-01

    Aquatic hyphomycetes play an essential role in the decomposition of allochthonous organic matter which is a fundamental process driving the functioning of forested headwater streams. We studied the effect of anthropogenic acidification on aquatic hyphomycetes associated with decaying leaves of Fagus sylvatica in six forested headwater streams (pH range, 4.3-7.1). Non-metric multidimensional scaling revealed marked differences in aquatic hyphomycete assemblages between acidified and reference streams. We found strong relationships between aquatic hyphomycete richness and mean Al concentration (r = -0.998, p < 0.0001) and mean pH (r = 0.962, p < 0.002), meaning that fungal diversity was severely depleted in acidified streams. By contrast, mean fungal biomass was not related to acidity. Leaf breakdown rate was drastically reduced under acidic conditions raising the issue of whether the functioning of headwater ecosystems could be impaired by a loss of aquatic hyphomycete species.

  17. Transit times from rainfall to baseflow in headwater catchments estimated using tritium: the Ovens River, Australia

    NASA Astrophysics Data System (ADS)

    Cartwright, I.; Morgenstern, U.

    2015-06-01

    Headwater streams contribute a significant proportion of the total flow to many river systems, especially during summer low-flow periods. However, despite their importance, the time taken for water to travel through headwater catchments and into the streams (the transit time) is poorly constrained. Here, 3H activities of stream water are used to define transit times of water contributing to streams from the upper reaches of the Ovens River in southeast Australia at varying flow conditions. 3H activities of the stream water varied from 1.63 to 2.45 TU, which are below the average 3H activity of modern local rainfall (~3 TU). The highest 3H activities were recorded following higher winter flows and the lowest 3H activities were recorded at summer low-flow conditions. Variations of major ion concentrations and 3H activities with streamflow imply that different stores of water from within the catchment (e.g. from the soil or regolith) are mobilised during rainfall events rather than there being simple dilution of an older groundwater component by event water. Mean transit times calculated using an exponential-piston flow model range between 5 and 31 years and are higher at summer low-flow conditions. Mean transit times calculated using other flow models (e.g. exponential flow or dispersion) are similar. There are broad correlations between 3H activities and the percentage of rainfall exported from each catchment and between 3H activities and Na and Cl concentrations that allow first-order estimates of mean transit times in adjacent catchments or at different times in these catchments to be made. Water from the upper Ovens River has similar mean transit times to the headwater streams implying there is no significant input of old water from the alluvial gravels. The observation that the water contributing to the headwater streams in the Ovens catchment has a mean transit time of years to decades implies that these streams are buffered against rainfall variations on

  18. Transit times from rainfall to baseflow in headwater catchments estimated using tritium: the Ovens River, Australia

    NASA Astrophysics Data System (ADS)

    Cartwright, I.; Morgenstern, U.

    2015-09-01

    Headwater streams contribute a significant proportion of the total flow to many river systems, especially during summer low-flow periods. However, despite their importance, the time taken for water to travel through headwater catchments and into the streams (the transit time) is poorly understood. Here, 3H activities of stream water are used to define transit times of water contributing to streams from the upper reaches of the Ovens River in south-east Australia at varying flow conditions. 3H activities of the stream water varied from 1.63 to 2.45 TU, which are below the average 3H activity of modern local rainfall (2.85 to 2.99 TU). The highest 3H activities were recorded following higher winter flows and the lowest 3H activities were recorded at summer low-flow conditions. Variations of major ion concentrations and 3H activities with streamflow imply that different stores of water from within the catchment (e.g. from the soil or regolith) are mobilised during rainfall events rather than there being simple dilution of an older groundwater component by event water. Mean transit times calculated using an exponential-piston flow model range from 4 to 30 years and are higher at summer low-flow conditions. Mean transit times calculated using other flow models (e.g. exponential flow or dispersion) are similar. There are broad correlations between 3H activities and the percentage of rainfall exported from each catchment and between 3H activities and Na and Cl concentrations that allow first-order estimates of mean transit times in adjacent catchments or at different times in these catchments to be made. Water from the upper Ovens River has similar mean transit times to the headwater streams implying there is no significant input of old water from the alluvial gravels. The observation that the water contributing to the headwater streams in the Ovens catchment has a mean transit time of years to decades implies that these streams are buffered against rainfall variations on

  19. Do the coarsest bed fractions and stream power record contemporary trends in steep headwater channels?

    NASA Astrophysics Data System (ADS)

    Galia, Tomáš; Škarpich, Václav

    2016-11-01

    Three stream channels that were devoid of evidence of past debris flows and one headwater channel that contained debris flow deposits in the flysch western Carpathians, Czech Republic were selected to test relationships between in-channel processes, bed sediments, and unit stream power calculated for bankfull and Q20 flows. Contemporary depositional or erosional trends in the examined headwaters were linked with bed sediments that were represented by the coarsest cobble and boulder fraction with a mean calculated from the five largest particles. The downstream trends of the unit stream power were derived for a bankfull discharge and a well-documented 20-year flood event. In addition, the flow competences during the discharges were calculated using indirect bedload transport measurements. Downstream fining of the cobble and boulder fraction was observed in all of the studied headwaters, and unique downstream variations of the unit stream power were calculated for the longitudinal profiles. The single-thread streams that were devoid of evidence of debris flow events exhibited direct relations between the coarsest sediment size and the unit stream power, especially as calculated for the 20-year flood event and for erosional/depositional trends of the channel. The downstream coarsening of the bed material that was accompanied by an increase in the unit stream power was usually observed in the case of deeply incised (> 0.5 m above the assumed bankfull depth) channel reaches. The calculated competence of the 20-year flow was up to twofold higher than that required to entrain the largest bed particle diameters in those channel reaches, and even the bankfull flow was potentially capable of transporting the coarsest bed particles in certain of the reaches. On the other hand, some depositional channel reaches evidently led to the disconnectivity of transport of the coarsest bed material even in the case of the 20-year flood event. The longitudinal profile of the channel that

  20. Integrated Hydro-geomorphological Monitoring System of the Upper Bussento river basin (Cilento and Vallo Diano Geopark, S-Italy)

    NASA Astrophysics Data System (ADS)

    Guida, D.; Cuomo, A.; Longobardi, A.; Villani, P.; Guida, M.; Guadagnuolo, D.; Cestari, A.; Siervo, V.; Benevento, G.; Sorvino, S.; Doto, R.; Verrone, M.; De Vita, A.; Aloia, A.; Positano, P.

    2012-04-01

    are organized into a relational geodatabase supporting tracer testings, space-time analysis and hydrological modeling. At the moment, three main station for hourly streamflow measurements are located at the terminal sections of the main basin and the two main sub-basin; secondary stations for weekly discharge measurements are located along the Upper Bussento river segment, upstream and downstream of each river reach or tributary catchments or karst spring inflow. Temporary stations are located in the representative sections of the catchments to detect stream flow losses into alluvial beds or experimental parcels in the bare karst and forested sandstone headwaters. Streamflow measurements are combined with geochemical survey and water sampling for Radon activity concentration measurements. Results of measurement campains in Radon space-time distribution within the basin are given in other contribution of same EGU session. Monitoring results confirm the hourly, daily, weekly and monthly hydrological data and validate outcomes of semi-distributed hydrological models based on previously time series, allowing both academic consultants and institutional subject to extend the Integrated Hydro-geomorphological Monitoring System to the surrounding drainage areas of the Cilento and Vallo di Diano Geopark. Keywords: River-aquifer interaction, Upper Bussento river basin, monitoring system, hydro-geomorphology, semi-distributed hydrological model. Table 1: Comparative, hierarchical Hydro-morpho-climate entities Hierarchy levelArea (Km2) Scale Orography Entity Climate Entity Morfological Entity Areal Drainage Entity Linear Drainage Entity VIII 106 1:15E6 Orogen Macroscale α Morphological Region Hydrological Region VII 105 1:10E6 Chain Sistem Macroscale β Morphological Province Hydrological Province VI 104 1:5E5 Chain Mesoscale α Morphological Sistem Basin River V 103 1:2,5E5Chain Segment Mesoscale β Morphological Sub-systemSub-Basin Torrent IV 100 1:1,0E5Orographic Group

  1. Susquehanna River Basin Hydrologic Observing System (SRBHOS)

    NASA Astrophysics Data System (ADS)

    Reed, P. M.; Duffy, C. J.; Dressler, K. A.

    2004-12-01

    In response to the NSF-CUAHSI initiative for a national network of Hydrologic Observatories, we propose to initiate the Susquehanna River Basin Hydrologic Observing System (SRBHOS), as the northeast node. The Susquehanna has a drainage area of 71, 410 km2. From the headwaters near Cooperstown, NY, the river is formed within the glaciated Appalachian Plateau physiographic province, crossing the Valley and Ridge, then the Piedmont, before finishing its' 444 mile journey in the Coastal Plain of the Chesapeake Bay. The Susquehanna is the major source of water and nutrients to the Chesapeake. It has a rich history in resource development (logging, mining, coal, agriculture, urban and heavy industry), with an unusual resilience to environmental degradation, which continues today. The shallow Susquehanna is one of the most flood-ravaged rivers in the US with a decadal regularity of major damage from hurricane floods and rain-on-snow events. As a result of this history, it has an enormous infrastructure for climate, surface water and groundwater monitoring already in place, including the nations only regional groundwater monitoring system for drought detection. Thirty-six research institutions have formed the SRBHOS partnership to collaborate on a basin-wide network design for a new scientific observing system. Researchers at the partner universities have conducted major NSF research projects within the basin, setting the stage and showing the need for a new terrestrial hydrologic observing system. The ultimate goal of SRBHOS is to close water, energy and solute budgets from the boundary layer to the water table, extending across plot, hillslope, watershed, and river basin scales. SRBHOS is organized around an existing network of testbeds (legacy watershed sites) run by the partner universities, and research institutions. The design of the observing system, when complete, will address fundamental science questions within major physiographic regions of the basin. A nested

  2. [Phosphorus Fractions and Release Risk in Surface Sediments of an Agricultural Headwater Stream System in Hefei Suburban, China].

    PubMed

    Pei, Ting-ting; Li, Ru-zhong; Gao, Su-di; Luo, Yue-ying

    2016-02-15

    A typical water system of agricultural headwater stream in Chaohu Lake basin was selected as the study area, and 17, 16, 14 and 13 surface sediments were collected from the four styles of stream, respectively, including ponds, branches, main channel and mainstream deep pools, in October 2014 (in autumn) and April 2015 (in spring). The forms and space-time variations of phosphorus in the sediments were analyzed. Clustering and variance analysis were conducted on the phosphorus forms data from the four styles of stream by means of multivariate statistical analyses. We quantified the phosphorus release risk (PSI) and identified the main impact factors of PSI via calculating the phosphorus sorption index (PSI) and the correlation analysis. The results showed that: (1) The contents of TP in the surface sediments ranged from 137.517 to 1709.229 mg x kg(-1) with an average value of 532. 245 mg x kg(-1), and the order of the average contents of phosphorus forms was IP (350.347 mg x kg(-1)) > OP (167.333 mg x kg(-1)) > Fe/Al-P ( 78. 869 mg x kg(-1)) > Ca-P (56.343 mg x kg(-1)) > Ex-P (6.609 mg x kg(-1)); (2) The contents of phosphorus forms had the same trend in all the four stream styles, which was deep pool > main channel > branch > pond; (3) In autumn, the deep pool and main channel were clustered into one class, while the pond and branch were clustered into the other class. In spring, branch, main channel and deep pool were clustered into the same class; (4) Variance analysis showed that the differences among the four stream styles were larger in autumn than in spring; (5) The PSI of the surface sediments ranged between 24.49 and 69.94 (mg x L(-1) x (100 g x micromol)(-1). The PSI in spring was lower than that in spring, indicating that phosphorus release risk of surface sediment was higher in spring than in autumn. (6) PSI had a significant negative correlation with Ex-P, IP and pH.

  3. Temporal and spatial dynamics of carbon and nitrogen in headwater snow-dominated catchments, Jemez Mountains, New Mexico

    NASA Astrophysics Data System (ADS)

    Dannemann, F. K.; Zapata, X.; McIntosh, J. C.; Perdrial, J. N.; Brooks, P. D.; Chorover, J.; Lohse, K. A.; Fricke, H. C.

    2011-12-01

    The concentration and availability of stream nutrients, particularly dissolved organic carbon (DOC) and nitrogen species, determine aquatic system productivity, and are important indicators of catchment hydrobiogeochemical processes. In semi-arid montane areas, such as the Valles Caldera National Preserve located within the Jemez River Basin, NM, an understanding of the relationship between discharge and nutrient concentrations is particularly important. Although the annual hydrograph is dominated (~40%) by spring snowmelt, similar to well studies sites in the northern Rockies, the JRB region receives a much larger percentage of precipitation associated with summer rainfall, and consequently may provide insight into how more northerly catchments will respond to changing climate. This study focuses on four headwater catchments: History Grove, La Jara, Upper Jaramillo and Upper Redondo, over two water years (2009 to 2011) to examine how nutrient concentrations vary as a function of hillslope aspect, catchment hydrologic responses, seasonality, and discharge. Stream water grab samples were collected on a monthly to weekly basis from 2009 to 2011 and analyzed for inorganic carbon (DIC), dissolved organic carbon (DOC) and nitrogen species (total dissolved nitrogen (DN), NO3, NO2, NH4). DOC and DN concentrations in stream waters from all 4 catchments are positively correlated, indicating a tight coupling of carbon and nitrogen. During dry periods (September to February) stream waters have high DIC (4.8-7.6 mg/L), and low DOC (1.6-2.7 mg/L) and DN (<0.3 mg/L) concentrations, indicating that stream water is dominated by groundwater inputs. In contrast, during spring snowmelt (March-May) stream waters have high DOC (2.9-6.2 mg/L) and DN (0.2-0.5mg/L) concentrations and low DIC (3.1-4.5mg/L) values; the majority of DN is comprised of organic-N. These results suggest flushing of shallow soil waters during snowmelt periods. High DIC (5.8-6.3mg/L), and low DOC (1.7-4.0mg/L) and

  4. The relationship between soil heterotrophic activity, soil dissolved organic carbon (DOC) leachate, and catchment-scale DOC export in headwater catchments

    USGS Publications Warehouse

    Brooks, P.D.; McKnight, Diane M.; Bencala, K.E.

    1999-01-01

    Dissolved organic carbon (DOC) from terrestrial sources forms the major component of the annual carbon budget in many headwater streams. In high-elevation catchments in the Rocky Mountains, DOC originates in the upper soil horizons and is flushed to the stream primarily during spring snowmelt. To identify controls on the size of the mobile soil DOC pool available to be transported during the annual melt event, we measured soil DOC production across a range of vegetation communities and soil types together with catchment DOC export in paired watersheds in Summit County, Colorado. Both surface water DOC concentrations and watershed DOC export were lower in areas where pyrite weathering resulted in lower soil pH. Similarly, the amount of DOC leached from organic soils was significantly smaller (p < 0.01) at sites having low soil p H. Scaling point source measurements of DOC production and leaching to the two basins and assuming only vegetated areas contribute to DOC production, we calculated that the amount of mobile DOC available to be leached to surface water during melt was 20.3 g C m-2 in the circumneutral basin and 17.8 g C m-2 in the catchment characterized by pyrite weathering. The significant (r2 = 0.91 and p < 0.05), linear relationship between overwinter CO2 flux and the amount of DOC leached from upper soil horizons during snowmelt suggests that the mechanism for the difference in production of mobile DOC was heterotrophic processing of soil carbon in snow-covered soil. Furthermore, this strong relationship between over-winter heterotrophic activity and the size of the mobile DOC pool present in a range of soil and vegetation types provides a likely mechanism for explaining the interannual variability of DOC export observed in high-elevation catchments.

  5. Influence of basin connectivity on sediment source, transport, and storage within the Mkabela Basin, South Africa

    NASA Astrophysics Data System (ADS)

    Miller, J. R.; Mackin, G.; Lechler, P.; Lord, M.; Lorentz, S.

    2013-02-01

    The management of sediment and other non-point source (NPS) pollution has proven difficult, and requires a sound understanding of particle movement through the drainage system. The primary objective of this investigation was to obtain an understanding of NPS sediment source(s), transport, and storage within the Mkabela Basin, a representative agricultural catchment within the KwaZulu-Natal Midlands of eastern South Africa, by combining geomorphic, hydrologic and geochemical fingerprinting analyses. The Mkabela Basin can be subdivided into three distinct subcatchments that differ in their ability to transport and store sediment along the axial valley. Headwater (upper catchment) areas are characterized by extensive wetlands that act as significant sediment sinks. Mid-catchment areas, characterized by higher relief and valley gradients, exhibit few wetlands, but rather are dominated by a combination of alluvial and bedrock channels that are conducive to sediment transport. The lower catchment exhibits a low-gradient alluvial channel that is boarded by extensive riparian wetlands that accumulate large quantities of sediment (and NPS pollutants). Fingerprinting studies suggest that silt- and clay-rich layers found within wetland and reservoir deposits of the upper and upper-mid subcatchments are derived from the erosion of fine-grained, valley bottom soils frequently utilized as vegetable fields. Coarser-grained deposits within these wetlands and reservoirs result from the erosion of sandier hillslope soils extensively utilized for sugar cane, during relatively high magnitude runoff events that are capable of transporting sand-sized sediment off the slopes. Thus, the source of sediment to the axial valley varies as a function of sediment size and runoff magnitude. Sediment export from upper to lower catchment areas was limited until the early 1990s, in part because the upper catchment wetlands were hydrologically disconnected from lower parts of the watershed during

  6. Assessing the ecological status of the Cisadane River’s headwaters using benthic macroinvertebrates

    NASA Astrophysics Data System (ADS)

    Krisanti, M.; Wardiatno, Y.; Anzani, Y. M.

    2017-01-01

    Benthic macroinvertebrates are commonly used in river health biomonitoring. In monitoring program biotic indices are now widely established in water quality monitoring around the world, including in the tropical countries. The aim of this study was to reveal the ecological status of Cisadane River’s headwaters in inside and outside of Mount Halimun-Salak National Park by using benthic macroinvertebrates. The research was conducted in the headwaters of Cisadane River located in Mount Halimun-Salak National Park. Macroinvertebrates were collected from four sites, i.e. inside the park (station 1, 2, 3, and 4) and from two sites outside the park (station 5 and 6). Collections were made twice a month, starting from April to June 2015 by means of Surber sampler (frame area 30x30 cm). A total of 65 genera from 38 families and 11 orders were found in the river. The results showed that based on diversity index, Lincoln Quality Index (LQI), Family Biotic Index (FBI), and Stream Invertebrate Grade Number Average Level 2 (SIGNAL 2), stations located within national park were ecologically better than those outside national park. Rivers with well-preserved riverside vegetation, as in the national park area have greater ecological status.

  7. Low prevalence of chytrid fungus (Batrachochytrium dendrobatidis) in amphibians of U.S. headwater streams

    USGS Publications Warehouse

    Hossack, Blake R.; Adams, Michael J.; Campbell Grant, Evan H.; Pearl, Chistopher A.; Bettaso, James B.; Barichivich, William J.; Lowe, Winsor H.; True, Kimberly; Ware, Joy L.; Corn, Paul Stephen

    2010-01-01

    Many declines of amphibian populations have been associated with chytridiomycosis, a disease caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd). Despite the relatively high prevalence of chytridiomycosis in stream amphibians globally, most surveys in North America have focused primarily on wetland-associated species, which are frequently infected. To better understand the distribution and prevalence of Bd in headwater amphibian communities, we sampled 452 tailed frogs (Ascaphus truei and Ascaphus montanus) and 304 stream salamanders (seven species in the Dicamptodontidae and Plethodontidae) for Bd in 38, first- to third-order streams in five montane areas across the United States. We tested for presence of Bd by using PCR on skin swabs from salamanders and metamorphosed tailed frogs or the oral disc of frog larvae. We detected Bd on only seven individuals (0.93%) in four streams. Based on our study and results from five other studies that have sampled headwater- or seep-associated amphibians in the United States, Bd has been detected on only 3% of 1,322 individuals from 21 species. These results differ strongly from surveys in Central America and Australia, where Bd is more prevalent on stream-breeding species, as well as results from wetland-associated anurans in the same regions of the United States that we sampled. Differences in the prevalence of Bd between stream- and wetland-associated amphibians in the United States may be related to species-specific variation in susceptibility to chytridiomycosis or habitat differences.

  8. Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: Implications for resilience

    USGS Publications Warehouse

    Gothe, Emma; Sandin, Leonard; Allen, Craig R.; Angeler, David G.

    2014-01-01

    The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.

  9. Characterization of hydrologic inputs and streamflow pathways in headwater catchments of Boulder Creek Watershed, Colorado

    NASA Astrophysics Data System (ADS)

    Cowie, R. M.; Williams, M. W.; Mills, T. J.

    2012-12-01

    Streamflow pathways were investigated using isotopic and geochemical tracers in two gauged headwater catchments located at different elevations within the forested area of Boulder Creek Watershed, Colorado. Using diagnostic tools of mixing models indicates that both catchments fit reasonable well to a 1-D (two endmember) model for streamflow generation. End member mixing analysis (EMMA) suggests that streamflow at the lower elevation Gordon Gulch catchment (mean elevation 2627 m) was a combination of shallow subsurface flow and groundwater with limited influence from direct runoff. Steamflow at the higher elevation Como Creek catchment (mean elevation 3230 m) was a combination of runoff from snowmelt and groundwater. During the study period the total annual precipitation and the amount of precipitation falling as snow increased with elevation from 456 mm (41% snow) at Gordon Gulch to 804 mm (71% snow) at Como Creek. The resulting increase in winter snow accumulation at Como Creek demonstrates differences in timing and magnitude of hydrologic inputs between the two catchments and provides a potential driver for the differences in streamflow pathways. These results highlight the importance of understanding variations in streamflow pathways in relation to climatic variations across headwater mountain catchments. The broader impacts of streamflow pathway variations on steam nutrients will also be addressed.

  10. Decoupling of carbon dioxide and dissolved organic carbon in boreal headwater streams

    NASA Astrophysics Data System (ADS)

    Winterdahl, Mattias; Wallin, Marcus B.; Karlsen, Reinert Huseby; Laudon, Hjalmar; Öquist, Mats; Lyon, Steve W.

    2016-10-01

    Streams and rivers emit large quantities of carbon dioxide (CO2) to the atmosphere. The sources of this CO2 are in-stream mineralization of organic carbon (OC) and CO2 input via groundwater inflow, but their relative importance is largely unknown. In this study, we quantified the role of in-stream OC mineralization as a source of CO2 in a number of nested boreal headwater streams. The results showed that mineralization of stream OC contributed 3% of CO2 supersaturation at time scales comparable to the estimated water travel times in the streams (<24 h). Mass balances showed that downstream losses of OC were ≤3% in low-order streams, whereas up to 16% of the OC was lost in the largest (fourth order) streams. In contrast, 85% of the CO2 was lost along the stream network (longest total stream length = 17 km). Under the assumption that in-stream OC mineralization was the main source of stream CO2, higher rates of OC mineralization (6% of OC) than those reported across the literature (≤0.7% of OC) would be required to sustain observed CO2 supersaturation. Further, model results indicated that groundwater inflows were sufficient to sustain observed stream CO2 concentrations. We hence conclude that in-stream OC mineralization was a minor source of CO2 in these boreal headwater systems and that the main source of stream CO2 was inflowing groundwater transporting CO2 originating from soil respiration.

  11. Appalachian Flood Hydrology in Headwater Watersheds: Hillslope Scale Studies at the Fernow Experimental Forest

    NASA Astrophysics Data System (ADS)

    Hicks, N. S.; Smith, J. A.

    2004-12-01

    Streamflow and rainfall are combined with observations from a network of 240 crest piezometers on two headwater watersheds (0.30 and 0.14 km2) at the Fernow Experimental Forest near Parsons, WV to examine the storm event response of forested, Appalachian watersheds. Weekly data from each piezometer, 5-minute data from over 20 piezometers, and continuous rainfall and streamflow measurements from 2003 and 2004 are used in these analyses. Watershed and piezometer response is examined in the context of antecedent conditions, rainfall accumulations, and rain rates. Piezometer nests (piezometers depths of 25, 50, and 100 cm) allow observations of the relative timing of saturation and piezometric head at different depths in the soil profile, allowing us to look for perched water tables and to distinguish saturation excess and infiltration excess runoff. Observations show pronounced heterogeneity even within the unchannelized swales of headwater watersheds. Piezometer observations yield insight into the dominate runoff production mechanisms for flood response and help to identify signatures in the watershed hydrographs due to different runoff production mechanisms. These hydrograph signatures will be used to help examine differences in watershed response for times when piezometers observations are not available, such as after historical logging of watersheds in the Fernow Experimental Forest.

  12. Productivity of ephemeral headwater riparian forests impacted by sedimentation in the southeastern United States coastal plain.

    PubMed

    Jolley, Rachel L; Lockaby, B Graeme; Cavalcanti, Guadalupe G

    2009-01-01

    Riparian forests serve an essential function in improving water quality through the filtering of sediments and nutrients from surface runoff. However, little is known about the impact of sediment deposition on productivity of riparian forests. Sediment inputs may act as a subsidy to forest productivity by providing additional nutrients for plant uptake or may act as a stress by creating anoxic soil conditions. This study determined how sediment deposition affected riparian forests along ephemeral headwater streams at Ft. Benning, Georgia, USA. Above- and belowground productivity, leaf-area index (LAI), and standing crop biomass for fine roots, shrubs, and trees were compared along a gradient of present sedimentation rates in 17 riparian forests. Annual litterfall production was determined from monthly collections using 0.25- m(2) traps; woody biomass was determined from annual diameter at breast height (DBH) measurements using species-specific allometric equations; fine root productivity was determined using sequential coring; LAI was measured by expanding specific leaf area by annual litterfall production; and shrub biomass was determined using species-specific biomass equations based on height and root collar diameter. Significant declines in litterfall, woody biomass production, fine root production, LAI, and shrub biomass were found with as little as 0.1 to 0.4 cm yr(-2) sedimentation. We conclude that the levels of sedimentation in this study do not subsidize growth in ephemeral headwater riparian forests but instead create a stress similar to that found under flooded conditions.

  13. Management of sediment and erosion processes in boreal headwaters affected by peatland drainage

    NASA Astrophysics Data System (ADS)

    Marttila, H.; Tammela, S.; Kløve, B.

    2009-04-01

    Peatland drainage for forestry, agriculture, peat harvesting and urban infrastructure has been altered landscape in Finland. Pristine peatlands and headwaters provide important hydrological and ecological functions that can be lost after drainage. The drainage has resulted in increase of forest resources but also negative environmental effects including changes in runoffs, erosion processes, siltation and eutrophication. The changes that can occur after drainage are, however, complex and must be better understood if the negative impacts of drainage are to be reduced or prevented. Especially erosion and transport processes of organic peat sediment are not well understood (Marttila and Kløve, 2008). Methods for controlling the sediment load include erosion and transport control practices in the catchment area (Marttila and Kløve, 2009; Tammela et al. 2009). The presentation/poster will present methods and preliminary results project from Northern Finland. The issues especially covered are sediment erosion and transport and methods to restore and reduce impacts of peatland drainage in boreal headwaters. Keywords: sediment transport, erosion, peatland drainage, organic and inorganic sediment, stream and catchment restoration, management, environment References: Marttila, H. and Kløve. B. 2008. Erosion and delivery of deposited peat sediment. Water Resources Research. 44 (6). Marttila, H. Kløve. B. 2009. Retention of sediment and nutrient loads with peak runoff control. Journal of Irrigation and Drainage Engineering (in press). Tammela, S. Marttila, H. and Kløve. B. 2009. Effect and design of an underminer structure on flow distribution and local bed topography (submitted).

  14. Hydrogeomorphic connectivity on roads crossing in rural headwaters and its effect on stream dynamics.

    PubMed

    Thomaz, Edivaldo L; Peretto, Gustavo T

    2016-04-15

    Unpaved roads are ubiquitous features that have been transforming the landscape through human history. Unpaved roads affect the water and sediment pathways through a catchment and impacts the aquatic ecosystem. In this study, we describe the effect of unpaved road on the hydrogeomorphic connectivity at the rural headwater scale. Measurement was based on the stream crossing approach, i.e., road superimposing the drainage system. We installed a Parshall flume coupled with single-stage suspended sediment sampler at each stream crossing. In addition, we displayed our monitoring scheme with an upscaling perspective from second-order to third-order stream. We concluded that the road-stream coupling dramatically changed the stream dynamic. The increase of discharge caused by roads at the headwater was 50% larger compared to unaffected streams. Additionally, suspended sediment concentration enhancement at stream crossings ranged from to 413% at second-order streams to 145% at third-order streams. The landform characteristics associated with the road network produced an important hydrogeomorphic disruption in the landscape. As a result, the sediment filter function of the riparian zone was reduced dramatically. Therefore, we recommend that projects for aquatic system restoration or conservation in rural landscape consider the role of the road network on stream dynamics.

  15. Are All Headwater Catchments the Same? Elevational Controls on Organic and Inorganic Nutrients in Headwater Catchments in the Boulder Creek Watershed, Colorado Front Range

    NASA Astrophysics Data System (ADS)

    Parman, J.; Williams, M. W.

    2009-12-01

    High-elevation ecosystems have become the focus of recent biogeochemical research due to their unique and complex processes, but also because these systems may serve as an early warning system for the potential effects of climate change. In the Colorado Front Range, it is expected that alpine areas will continue to experience greater annual precipitation, as well as an increase in atmospheric deposition of inorganic nitrogen (Williams and Tonnessen, 2000). Past studies have shown that these mountain systems tend to amplify such environmental changes in specific areas of the landscape. The Landscape Continuum Model (LCM, Seastedt et al., 2004) proposed a conceptual framework for how mountain ecosystems accumulate and redistribute exogenous material from the atmosphere and endogenous material derived from the mountain itself, emphasizing the importance of transport processes and redeposition of nutrients and water across highly varying and complex terrain. Here, we test the LCM by comparing and contrasting changes in organic and inorganic nutrients in stream waters of headwater catchments along an elevational gradient in the Colorado Front Range. We simultaneously collected water samples at four gauged headwater catchments: (1) Green Lakes Valley (3,500 m); (2) Como Creek (2,900 m); Gordon Gulch (2,400 m); and Betasso (1,830 m). All water samples were analyzed for DOC, DON, DOP, nitrate, and ammonium. Additionally, spectroscopic techniques were used to determine the quality of DOC. These measurements, along with supporting information on soil C:N ratios and climate data, allow us to determine how elevational position controls: (a) the redistribution of exogenous materials from the regional environment such as nitrate in wetfall; and (b) endogenous sources originating from montane areas such as DOC and DON, while controlling for catchment size, aspect, and underlying geology. Seastedt, T. R., W. D. Bowman, T. N. Caine, D. McKnight, A. Townsend & M. W. Williams (2004

  16. Documentation of input datasets for the soil-water balance groundwater recharge model of the Upper Colorado River Basin

    USGS Publications Warehouse

    Tillman, Fred D

    2015-01-01

    The Colorado River and its tributaries supply water to more than 35 million people in the United States and 3 million people in Mexico, irrigating more than 4.5 million acres of farmland, and generating about 12 billion kilowatt hours of hydroelectric power annually. The Upper Colorado River Basin, encompassing more than 110,000 square miles (mi2), contains the headwaters of the Colorado River (also known as the River) and is an important source of snowmelt runoff to the River. Groundwater discharge also is an important source of water in the River and its tributaries, with estimates ranging from 21 to 58 percent of streamflow in the upper basin. Planning for the sustainable management of the Colorado River in future climates requires an understanding of the Upper Colorado River Basin groundwater system. This report documents input datasets for a Soil-Water Balance groundwater recharge model that was developed for the Upper Colorado River Basin.

  17. Export of detritus and invertebrate from headwater streams: linking mountaintop removal and valley fill coal mining to downstream receiving waters

    EPA Science Inventory

    Mountaintop removal and valley fill (MTR/VF) coal mining has resulted in large scale alteration of the topography, reduced forest productivity, and burial of headwater streams in the U.S. Central Appalachians. Although MTR/VF coal mining has occurred for several decades and the ...

  18. Influence of Herbaceous Riparian Buffers on Fish and Amphibian Communities Within Channelized Headwater Streams in Central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbaceous riparian buffers are a widely used conservation practice in the United States for reducing nutrient, pesticide, and sediment loadings in agricultural streams. The importance of forested riparian zones for headwater streams has been documented, but the ecological impacts of herbaceous ripa...

  19. Peak Flow Responses and Recession Flow Characteristics After Thinning of Japanese Cypress Forest in a Headwater Catchment

    EPA Science Inventory

    We evaluated the effects of forest thinning on peak flow and recession characteristics of storm runoff in headwater catchments at Mie Prefecture, Japan. In catchment M5, 58.3% of stems were removed, whereas catchment M4 remained untreated as a control catchment. Storm precipitati...

  20. Distribution of Amphipods (Gammarus nipponensis Ueno) Among Mountain Headwater Streams with Different Legacies of Debris Flow Occurrence

    EPA Science Inventory

    To understand the impacts of debris flows on the distribution of an amphipod with limited dispersal ability in the context of stream networks, we surveyed the presence of Gammarus nipponensis in 87 headwater streams with different legacies of debris flow occurrence within an 8.5-...

  1. The burial of headwater streams in drainage pipes reduces in-stream nitrate retention: results from two US metropolitan areas

    EPA Science Inventory

    Nitrogen (N) retention in stream networks is an important ecosystem service that may be affected by the widespread burial of headwater streams in urban watersheds. Stream burial occurs when segments of a channel are encased in drainage pipe and buried beneath the land surface to...

  2. What do we know about past changes in the water cycle of Central Asian headwaters? A review

    NASA Astrophysics Data System (ADS)

    Unger-Shayesteh, Katy; Vorogushyn, Sergiy; Farinotti, Daniel; Gafurov, Abror; Duethmann, Doris; Mandychev, Alexander; Merz, Bruno

    2013-11-01

    We have reviewed about 100 studies on past changes in climate, snow cover, glaciers and runoff in Central Asian headwater catchments, which have been published in the past 20 years. We included studies published by Central Asian researchers in Russian language, which are usually not easily accessible to international researchers.

  3. Influence of adding small instream wood on fishes and hydrology within channelized agricultural headwater streams in central Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Large instream wood is well known for its importance in headwater streams because it promotes the development of pool habitat for fishes and provides them with cover from predators during the summer. However, little is known about the influence of small instream wood (diameter < 10 cm, length < 1 m...

  4. Mean annual runoff in the upper Ohio River basin, 1941-70, and its historical variation

    USGS Publications Warehouse

    Beall, Robert M.

    1978-01-01

    A map of the Ohio River basin above the Muskingum River shows patterns of mean annual runoff for the new climatologic and hydrologic reference period, 1941-70, and provides an up-to-date, consistent basis for consideration of this streamflow characteristic. The primary data base consisted of 98 long-term gaging-station records collected within this 27,300-square-mile (70,700-square-kilometer) headwater area of the Ohio River basin. Supplemental information was derived from 83 short-term records. Mean annual runoff is at a regional minimum of less than 12 inches (300 millimeters) in an area extending from the northern West Virginia panhandle to the headwaters of the Mahoning River in Ohio. Mean annual runoff of more than 32 inches {810 millimeters) occurs in parts of the upper Cheat River basin in West Virginia. The zone of high runoff trends northeastward along the western slopes of tile Allegheny Mountains; magnitudes diminish to about 25 inches (630 millimeters) at the eastern basin boundary near Ebensburg, Pa. Runoff of this magnitude occurs also in a band across tile upper Allegheny River basin in Pennsylvania. Ratios of mean annual discharge to the 30-year reference-period average were computed for each year of record for all long-term gaging stations. Annual discharges have ranged from about 30 percent to 200 percent of the 30-year mean. Graphed summaries of the annual ratios document the relative duration and magnitude of wet and dry periods during the past 65 years in the upper Ohio River basin.

  5. Understanding Changes in Water Availability in the Rio Grande/Rio Bravo del Norte Basin Under the Influence of Large-Scale Circulation Indices Using the Noah Land Surface Model

    NASA Technical Reports Server (NTRS)

    Khedun, C. Prakash; Mishra, Ashok K.; Bolten, John D.; Beaudoing, Hiroko K.; Kaiser, Ronald A.; Giardino, J. Richard; Singh, Vijay P.

    2012-01-01

    Water availability plays an important role in the socio-economic development of a region. It is however, subject to the influence of large-scale circulation indices, resulting in periodic excesses and deficits. An assessment of the degree of correlation between climate indices and water availability, and the quantification of changes with respect to major climate events is important for long-term water resources planning and management, especially in transboundary basins as it can help in conflict avoidance. In this study we first establish the correlation of the Pacific Decadal Oscillation (PDO) and El Nino-Southern Oscillation (ENSO) with gauged precipitation in the Rio Grande basin, and quantify the changes in water availability using runoff generated from the Noah land surface model. Both spatial and temporal variations are noted, with winter and spring being most influenced by conditions in the Pacific Ocean. Negative correlation is observed at the headwaters and positive correlation across the rest of the basin. The influence of individual ENSO events, classified using four different criteria, is also examined. El Ninos (La Ninas) generally cause an increase (decrease) in runoff, but the pattern is not consistent; percentage change in water availability varies across events. Further, positive PDO enhances the effect of El Nino and dampens that of La Nina, but during neutral/transitioning PDO, La Nina dominates meteorological conditions. Long El Ninos have more influence on water availability than short duration high intensity events. We also note that the percentage increase during El Ninos significantly offsets the drought-causing effect of La Ninas.

  6. Assessing mercury exposure and effects to American dippers in headwater streams near mining sites

    USGS Publications Warehouse

    Henny, Charles J.; Kaiser, James L.; Packard, Heidi A.; Grove, Robert A.; Taft, Mike R.

    2005-01-01

    To evaluate mercury (Hg) exposure and possible adverse effects of Hg on American dipper (Cinclus mexicanus) reproduction, we collected eggs and nestling feathers and the larval/nymph form of three Orders of aquatic macroinvertebrates (Ephemeroptera, Plecoptera and Trichoptera = EPT) important in their diet from three major headwater tributaries of the upper Willamette River, Oregon in 2002. The Coast Fork Willamette River is contaminated with Hg due to historical cinnabar (HgS) mining at the Black Butte Mine; the Row River is affected by past gold-mining operations located within the Bohemia Mining District, where Hg was used in the amalgamation process to recover gold; and the Middle Fork Willamette River is the reference area with no known mining. Methyl mercury (MeHg) concentrations (geometric mean) in composite EPT larvae (111.9 ng/g dry weight [dw] or 19.8 ng/g wet weight [ww]), dipper eggs (38.5 ng/g ww) and nestling feathers (1158 ng/g ww) collected from the Coast Fork Willamette were significantly higher than MeHg concentrations in EPT and dipper samples from other streams. Total mercury (THg) concentrations in surface sediments along the same Hg-impacted streams were investigated by others in 1999 (Row River tributaries) and 2002 (Coast Fork). The reported sediment THg concentrations paralleled our biological findings. Dipper breeding territories at higher elevations had fewer second clutches; however, dipper reproductive success along all streams (including the lower elevation and most Hg-contaminated Coast Fork), was judged excellent compared to other studies reviewed. Furthermore, MeHg concentrations in EPT samples from this study were well below dietary concentrations in other aquatic bird species, such as loons and ducks, reported to cause Hg-related reproductive problems. Our data suggest that either dipper feathers or EPT composites used to project MeHg concentrations in dipper feathers (with biomagnification factor of 10a??20??) may be used, but

  7. Diurnal variation of dominant nitrate retention processes in an agricultural headwater stream

    NASA Astrophysics Data System (ADS)

    Schuetz, Tobias; Ryabenko, Evgenia; Stumpp, Christine

    2015-04-01

    Nitrate and ammonium are introduced by agricultural practice into the environment and are transformed and retained on their pathway through aquatic environments. In particular, biological transformation processes (i.e. microbial denitrification or ammonium oxidation and assimilation) are responsible for the largest part of nitrate removal, which are also crucial processes in headwater streams. It is well known, that most of the biological processes are influenced by available (solar) energy fluxes, temperatures and dissolved oxygen concentrations, which vary with time and space. However, looking at biogeochemical hot spots in the landscapes` hydrological interface, the stream and river network (e.g. stream sections with a high biological activity), the temporal variability of biological processes can be an important control on total nitrate export. In this study, we therefore identified most important diurnal time periods for nitrate retention in a 75 m impervious section of an agricultural headwater stream using oxygen saturation dynamics and nitrate isotopes. We regularly measured discharge, hydro-geochemical and climate parameters, as well as nitrate and water isotopes in grab samples at three locations along the reach. On average, we observed a decrease of 10% in nitrate concentration from up- to downstream, which was only caused by biological processes and not by dilution. Nitrate isotope analysis indicated distinct trends along the reach and with time of the day. Both nitrate assimilation and nitrification caused significant changes in nitrate isotope distribution in the early day. To explain the distinct observed process dynamics from the morning to the afternoon, we simulated net primary production (NEP) and respiration using the river metabolism model RIVERMETC with observed oxygen concentrations and water temperatures. Comparing the results with the observed nitrate dynamics, the short time period when NEP occurs (~10:30 -12:30) seems to be crucial for

  8. Effects of bark beetle infestation on hydrology and land-energy feedbacks in mountain headwaters

    NASA Astrophysics Data System (ADS)

    Penn, C. A.; Maxwell, R. M.; Engdahl, N. B.; Clow, D. W.

    2013-12-01

    Infestation of mountain pine beetle (MPB) throughout the Rocky Mountain Region has caused substantial tree mortality in critical sub-alpine and montane zones. The potential changes in land-energy and water balances caused by MPB tree mortality are demonstrated through hillslope-scale integrated modeling and regional-scale atmospheric modeling using the ParFlow-CLM model for the headwaters of the Big Thompson watershed in Rocky Mountain National Park, Colo. ParFlow is a variably saturated, integrated groundwater and surface-water model that solves Richard's equation in 3D and routes overland flow with Manning's equation. Parflow is coupled with the Community Land Model (CLM) to incorporate land-surface processes and energy fluxes. The Big Thompson headwaters (358 km2) include sub-alpine and montane zones where forests are experiencing substantial tree mortality. The MPB infestation was documented in the watershed beginning in 1998 with many ecohydrological factors contributing to the rapid spread of infestation and tree mortality since 2007. In addition to vegetation information, data from multiple U.S. Geological Survey stream-gage and water-quality sites in the study area allow for comparisons between model output and observations. The ParFlow-CLM model of the Big Thompson headwaters uses a 0.01km2 grid-cell size with variable subsurface depth and is driven by distributed hourly meteorological forcing. Vegetation and associated land-cover changes related to MPB infestations are applied in the model through adjustments to parameters that reflect those found in forest ecology literature. Results at the hillslope-scale show significant changes in transpiration, snowfall, snowmelt, and the near-surface energy balance as a result of MPB tree mortality. Model simulations from MPB and non-MPB scenarios are being compared with observations of streamflow and analyzed for the magnitude of change in land-energy and water balances. This investigation supports regional water

  9. Assessing mercury exposure and effects to American dippers in headwater streams near mining sites.

    PubMed

    Henny, Charles J; Kaiser, James L; Packard, Heidi A; Grove, Robert A; Taft, Michael R

    2005-10-01

    To evaluate mercury (Hg) exposure and possible adverse effects of Hg on American dipper (Cinclus mexicanus) reproduction, we collected eggs and nestling feathers and the larval/nymph form of three Orders of aquatic macroinvertebrates (Ephemeroptera, Plecoptera and Trichoptera = EPT) important in their diet from three major headwater tributaries of the upper Willamette River, Oregon in 2002. The Coast Fork Willamette River is contaminated with Hg due to historical cinnabar (HgS) mining at the Black Butte Mine; the Row River is affected by past gold-mining operations located within the Bohemia Mining District, where Hg was used in the amalgamation process to recover gold; and the Middle Fork Willamette River is the reference area with no known mining. Methyl mercury (MeHg) concentrations (geometric mean) in composite EPT larvae (111.9 ng/g dry weight [dw] or 19.8 ng/g wet weight [ww]), dipper eggs (38.5 ng/g ww) and nestling feathers (1158 ng/g ww) collected from the Coast Fork Willamette were significantly higher than MeHg concentrations in EPT and dipper samples from other streams. Total mercury (THg) concentrations in surface sediments along the same Hg-impacted streams were investigated by others in 1999 (Row River tributaries) and 2002 (Coast Fork). The reported sediment THg concentrations paralleled our biological findings. Dipper breeding territories at higher elevations had fewer second clutches; however, dipper reproductive success along all streams (including the lower elevation and most Hg-contaminated Coast Fork), was judged excellent compared to other studies reviewed. Furthermore, MeHg concentrations in EPT samples from this study were well below dietary concentrations in other aquatic bird species, such as loons and ducks, reported to cause Hg-related reproductive problems. Our data suggest that either dipper feathers or EPT composites used to project MeHg concentrations in dipper feathers (with biomagnification factor of 10-20x) may be used, but with

  10. Empirical Relationships Between Watershed Attributes and Headwater Lake Chemistry in the Adirondack Region

    SciTech Connect

    Hunsaker, C.T.

    1987-01-01

    Surface water acidification may be caused or influenced by both natural watershed processes and anthropogenic actions. Empirical models and observational data can be useful for identifying watershed attributes or processes that require further research or that should be considered in the development of process models. This study focuses on the Adirondack region of New York and has two purposes: to (1) develop empirical models that can be used to assess the chemical status of lakes for which no chemistry data exist and (2) determine on a regional scale watershed attributes that account for variability in lake pH and acid-neutralizing capacity (ANC). Headwater lakes, rather than lakes linked to upstream lakes, were selected for initial analysis. The Adirondacks Watershed Data Base (AWDB), part of the Acid Deposition Data Network maintained at Oak Ridge National Laboratory (ORNL), integrates data on physiography, bedrock, soils, land cover, wetlands, disturbances, beaver activity, land use, and atmospheric deposition with the water chemistry and morphology for the watersheds of 463 headwater lakes. The AWD8 facilitates both geographic display and statistical analysis of the data. The report, An Adirondack Watershed Data Base: Attribute and Mapping Information for Regional Acidic Deposition Studies (ORNL/TM--10144), describes the AWDB. Both bivariate (correlations and Wilcoxon and Kruskal-Wallis tests) and multivariate analyses were performed. Fifty-seven watershed attributes were selected as input variables to multiple linear regression and discriminant analysis. For model development -200 lakes for which pH and ANC data exist were randomly subdivided into a specification and a verification data set. Several indices were used to select models for predicting lake pH (31 variables) and ANC (27 variables). Twenty-five variables are common to the pH and ANC models: four lake morphology, nine soil/geology, eight land cover, three disturbance, and one watershed aspect. An

  11. Grazer traits, competition, and carbon sources to a headwater-stream food web.

    PubMed

    McNeely, Camille; Finlay, Jacques C; Power, Mary E

    2007-02-01

    We investigated the effect of grazing by a dominant invertebrate grazer (the caddisfly Glossosoma penitum) on the energy sources used by other consumers in a headwater-stream food web. Stable isotope studies in small, forested streams in northern California have shown that G. penitum larvae derive most of their carbon from algae, despite low algal standing crops. We hypothesized that the caddisfly competes with other primary consumers (including mayflies) for algal food and increases their reliance on terrestrial detritus. Because Glossosoma are abundant and defended from predators by stone cases, their consumption of algal energy may reduce its transfer up the food chain. We removed Glossosoma (natural densities >1000 caddisflies/m2) from five approximately 4 m2) stream sections during the summer of 2000 and measured responses of algae, invertebrate primary consumers, and invertebrate predators. The treatment reduced Glossosoma biomass by 80-90%. We observed a doubling in chlorophyll a per area in sections with reduced Glossosoma abundance and aggregative increases in the biomass of undefended primary consumers. Heptageniid mayfly larvae consumed more algae (as measured by stable carbon isotope ratios and gut content analysis) in caddisfly removal plots at the end of the 60-day experiment, although not after one month. We did not see isotopic evidence of increased algal carbon in invertebrate predators, however. Patterns of caddisfly and mayfly diets in the surrounding watershed suggested that mayfly diets are variable and include algae and detrital carbon in variable proportions, but scraping caddisflies consume primarily algae. Caddisfly and mayfly diets are more similar in larger, more productive streams where the mayflies assimilate more algae. Isotopic analysis, in combination with measurements of macroinvertebrate abundance and biomass in unmanipulated plots, suggested that a substantial portion of the invertebrate community (>50% of biomass) was supported

  12. 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.

  13. Nutrients, Select Pesticides, and Suspended Sediment in the Karst Terrane of the Sinking Creek Basin, Kentucky, 2004-06

    USGS Publications Warehouse

    Crain, Angela S.

    2010-01-01

    This report presents the results of a study by the U.S. Geological Survey, in cooperation with the Kentucky Department of Agriculture, on nutrients, select pesticides, and suspended sediment in the karst terrane of the Sinking Creek Basin. Streamflow, nutrient, select pesticide, and suspended-sediment data were collected at seven sampling stations from 2004 through 2006. Concentrations of nitrite plus nitrate ranged from 0.21 to 4.9 milligrams per liter (mg/L) at the seven stations. The median concentration of nitrite plus nitrate for all stations sampled was 1.6 mg/L. Total phosphorus concentrations were greater than 0.1 mg/L, the U.S. Environmental Protection Agency's recommended maximum concentration, in 45 percent of the samples. Concentrations of orthophosphates ranged from less than 0.006 to 0.46 mg/L. Concentrations of nutrients generally were larger during spring and summer months, corresponding to periods of increased fertilizer application on agricultural lands. Concentrations of suspended sediment ranged from 1.0 to 1,490 mg/L at the seven stations. Of the 47 pesticides analyzed, 14 were detected above the adjusted method reporting level of 0.01 micrograms per liter (mug/L). Although these pesticides were detected in water-quality samples, they generally were found at less than part-per-billion concentrations. Atrazine was the only pesticide detected at concentrations greater than U.S. Environmental Protection Agency drinking water standard of 3 mug/L, and the maximum detected concentration was 24.6 mug/L. Loads and yields of nutrients, selected pesticides, and suspended sediment were estimated at two mainstream stations on Sinking Creek, a headwater station (Sinking Creek at Rosetta) and a station at the basin outlet (Sinking Creek near Lodiburg). Mean daily streamflow data were available for the estimation of loads and yields from a stream gage at the basin outlet station; however, only periodic instantaneous flow measurements were available for the

  14. Managing the three-rivers headwater region, china: from ecological engineering to social engineering.

    PubMed

    Fang, Yiping

    2013-09-01

    The three-rivers headwater region (THRHR) of Qinghai province, China plays a key role as source of fresh water and ecosystem services for central and eastern China. Global warming and human activities in the THRHR have threatened the ecosystem since the 1980s. Therefore, the Chinese government has included managing of the THRHR in the national strategy since 2003. The State Integrated Test and Demonstration Region of the THRHR highlights the connection with social engineering (focus on improving people's livelihood and well-being) in managing nature reserves. Based on this program, this perspective attempts a holistic analysis of the strategic role of the THRHR, requirements for change, indices of change, and approaches to change. Long-term success of managing nature reserves requires effective combination of ecological conservation, economic development, and social progress. Thus, the philosophy of social engineering should be employed as a strategy to manage the THRHR.

  15. Recovery of headwater stream flora following the 1989-1992 groundwater drought

    NASA Astrophysics Data System (ADS)

    Holmes, Nigel T. H.

    1999-02-01

    Over a three year period in spring, summer and autumn from 1993 to 1995 118 sites on 24 headwater reaches of groundwater streams were investigated. Half were also surveyed at least once the previous year. Example rivers were chosen from catchments where there are no abstractions, where there are small or large historical ones, and where reductions or variations in abstractions were likely to occur during the study period.Key objectives of the study were to identify the effects of atypical low flows and bed drying on aquatic and wetland plants following an exceptionally long period of poor groundwater recharge between 1989-92. The extended drought, followed by two years of very good groundwater recharge, provided a unique opportunity to determine the rate, and extent, of recovery. Such knowledge is crucial for conservation bodies, water regulators and water utilities to help them make judgements on the degree of impacts groundwater abstractions have/could have on river flows, and separating these from natural causes.The macrophyte survey data have been used to develop a classification system for headwater streams fed by groundwater. Thirteen different community types were recognised, these giving a clear insight into the flora expected in groundwater streams based primarily on flow periodicity and channel form. Determining the behaviour of individual species helps in environmental assessment of proposed new abstractions, and allows accurate predictions on which ones might decline, be lost or invade. It is equally valuable for predicting the benefits of alleviation strategies based on target flows.Lesser water-parsnip, brook water-crowfoot, blunt-fruited water-starwort and whorl-grass were identified as the most characteristic species of perennial reaches of headwater chalk streams. Pond water-crowfoot only dominates in reaches where flow fails for short periods in late autumn. Marsh foxtail is a classic indicator of winter wet/summer dry flow channels.The River Ver

  16. Effects of bedrock groundwater on landslide occurrences in a steep headwater catchment

    NASA Astrophysics Data System (ADS)

    Kosugi, K.; Fujimoto, M.; Sando, Y.; Mizuyama, T.; Kinoshita, A.

    2011-12-01

    Previous studies have shown that the formation of groundwater in the soil mantle greatly affects slope instability on steep landscapes. To predict landslides, mathematical models based on a geographic information system, which organize geographic data such as information on upslope contributing areas and the local slope gradient, have been developed and tested. Although such models can be used to calculate the topographically driven convergence of rainwater and groundwater table developments in the soil mantle, thus providing a spatially distributed prediction of landslide occurrences, the accuracy of these mathematical models is still limited, mainly because they ignore storm responses in underlying bedrock. Recent research has provided credible information on the importance of bedrock groundwater on surface hydrological processes in headwater catchments. To elucidate the effects of bedrock groundwater, the dynamics of bedrock groundwater should be measured directly. However, intensive monitoring of bedrock groundwater is rare in mountains with steep topography. Consequently, how bedrock groundwater controls landslides in a steep headwater catchment is in dispute. In this study, we conducted long-term hydrological observations using densely nested bedrock wells along with monitoring of discharge hydrograph and soil mantle groundwater in a steep headwater catchment underlain by granitic bedrock. Bedrock wells with depths of 7-78 m were drilled at 31 points within the 2.10-ha catchment. Results showed that a hollow of bedrock aquifer was located at a ridge in the surface topography, clearly indicating bedrock groundwater flow across topographic divides. Around a point where the bedrock groundwater exfiltrated, we found scars of landslides. Such landslides cannot be explained by mathematical hydrology models, which calculate the topographically driven convergence of rainwater in the soil mantle. Moreover, at a point along the main hollow of the watershed, we observed

  17. 'invisible' DOM in hourly-resolved headwater river records from Northern Amazonia

    NASA Astrophysics Data System (ADS)

    Pereira, R.; Bovolo, C.; Spencer, R. G.; Hernes, P. J.; Tipping, E.; Vieth-Hillebrand, A.; Chappell, N.; Lewis-Franklin, A.; Parkin, G.; Wagner, T.

    2012-12-01

    Global river networks annually process ~3 billion tonnes of organic carbon but only ~17% reaches the ocean. These estimates suggest rivers are not mere transportation pipes but biogeochemical reactors. Inland waters are therefore fundamental to the understanding of carbon and nutrient interactions between land and ocean. Within these global estimates, tropical rivers contribute ~two-thirds of the global dissolved organic matter flux to the ocean. Recent studies suggest that up to 50% of the CO2 outgassed from tropical rivers is derived from terrestrial organic matter and that the terrestrial-aquatic interface in river headwaters are hotspots of biochemical activity. However, to date, most tropical riverine studies focus on the main river stem or mouth and therefore the dynamics of tropical headwater organic matter cycling within the global carbon cycle are unknown. We present a geochemical and hydrological time-series (sub-hourly resolution) of river water DOC concentration, source and composition from a pristine lowland rainforest headwater of the Burro Burro River, a tributary of the Essequibo River, the 3rd largest river in S. America. We show that during and after a rainstorm event, DOC concentrations increase an order of magnitude (10 to 114mg/L) in less than 30 mins, far exceeding the entire seasonal DOC range measured in 2010 and 2011 (17-28mg/L). The source (δ13C-DOC) of DOC during the rainstorm event changes from microbial/aquatic (-21.9‰ to -25.7‰) at low/intermediate DOC concentration to C3 vegetation supply (-26.8‰ to -30.3‰) during peak DOC flushing. First radiocarbon data shows that riverine DOC is relatively young (106.8-110.9 %modern), however, tropical soils suggest a potential for organic matter to be preserved (360-1200 BP). The fundamental relationship between DOC and coloured dissolved organic matter (CDOM), measured as UV absorbance (SUVA254), holds only for low riverine DOC concentrations with proportionally high lignin contribution

  18. Longitudinal patterns in carbon and nutrient export from urban watersheds with contrasting headwater management

    NASA Astrophysics Data System (ADS)

    Smith, R. M.; Kaushal, S.; Pennino, M. J.

    2012-12-01

    Stormwater management in urban areas presents challenges and opportunities to enhance water quality while simultaneously protecting property and infrastructure. Through several generations, stormwater management practices have evolved from 'gray infrastructure' such as pipes and ditches designed to quickly transport water away from the landscape, to more 'green infrastructure' projects meant to allow for biological processing and retention of urban runoff. Implementation of these practices has replaced traditional stream burial with bioretention cells, wetlands, and ponds. We hypothesize that these contrasting green versus gray strategies for headwater management may have significant consequences for the delivery and processing of dissolved carbon, nitrogen, and phosphorous. To address this hypothesis, we compared two paired urbanized watersheds with different stormwater management by measuring the longitudinal export of DOC, DIC, TDN, PO4+, and major anions, and characterizing dissolved organic matter using Fluorescence Index (FI) and Spectral Slope. Both watersheds were located in the Baltimore Ecosystem Study Long Term Ecological Research (LTER) site. Dead Run is an urbanized catchment with prevalent stream burial and minimal stormwater management which was implemented after initial development. Red Run is a similarly sized watershed with more recent development and comprehensive stormwater management (wetlands, ponds, bioretention cells, sand filters) and 100m wide stream buffer areas. In each of these contrasting watersheds, we chose two headwater streams which drain SWM features and one stream that terminates at a storm drain. We measured longitudinal changes in export by conducting a synoptic survey of both watersheds in which flow and water chemistry were measured every 500m in the main stem and approximately every 250m in the selected tributaries. Within watersheds, we found differences in the C, N and P loads from SWM and non-SWM streams. In Red Run, DOC

  19. Temporal and spatial variations of precipitation in the Jinsha River basin during 1961-2010

    NASA Astrophysics Data System (ADS)

    Zeng, X.; Zhao, N.; Sun, H.; Ye, L.; Zhai, J.

    2015-05-01

    Knowing the variations of precipitation at the basin scale is very important to study the impacts of climate change on water resources and hydrological processes. To achieve the temporal and spatial variations of precipitation on long time scales and some extreme indicators in the Jinsha River basin, some typical precipitation indices were analysed based on daily precipitation data for 1961-2010 for the research area. The results showed that AP had a certain increasing tendency without passing the significance test, while AP in the lower reach of the basin decreased slightly. PFS had no obvious changes, while MP through a year (except rainfall in September and December) had a slight increasing tendency. In addition, AP and PFS showed obvious spatial differences, and the higher rainfall area was located in the lower basin especially in the Hengduan Mountain area. LRD and MRD increased slightly in the upper and middle regions, while they decreased slightly in the lower basin. HRD increased over most of the whole basin, but it had a decreasing tendency in the headwater region and around Dege station but did not pass the significance test. DD and CDD in one year showed similar spatial change patterns and had an obvious decreasing tendency in the upper and middle basin, while they had an obvious increasing tendency in the lower basin. CWD almost decreased over the whole basin, and decreased significantly in a small part of the lower basin. The temporal changes of the typical precipitation indices may confirm the possible increasing tendency for occurrence of drier climate and even drought events in the downstream of Jinsha River basin.

  20. Unraveling soil moisture responses to storms and relationships to runoff in a headwater catchment

    NASA Astrophysics Data System (ADS)

    Singh, N.

    2015-12-01

    Soil moisture exhibits complex spatiotemporal patterns, both laterally across landscapes and vertically within soil profiles. These patterns of soil moisture can have strong influences on runoff generation, especially in catchments having large capacities for soil water storage and transmission. The body of literature on runoff generation is expansive, yet we still have a great deal to learn about how the spatial and temporal heterogeneity of soil moisture influences catchment-scale hydrologic responses to storm events. With this in mind, we investigated soil moisture responses to storm events across several landscape positions in a steep, forested headwater catchment. We measured volumetric water content (VWC) continuously for two years at 45 points representing different combinations of landscape position and soil depth within a 13 ha catchment at Coweeta Hydrologic Laboratory in the Southern Appalachian Mountains. We also monitored shallow groundwater levels at six locations within the catchment along with runoff at the catchment outlet. To investigate soil moisture response during events, we assessed absolute change in magnitude of VWC (Δs) and lag time (Δt) between peak VWC and peak precipitation for 39 events during the two-year study period. Our results showed that storm depth and antecedent moisture explained some of the spatiotemporal patterns of Δs; however, the explanatory power varied with the hillslope and season. Furthermore, we did not detect topographic control of Δs or Δt at most of the locations monitored. By evaluating the sequence of Δt, groundwater response, and runoff response for each storm, we characterized the hydrologic behavior of the study hillslopes for the 39 storm events.The characterization of hydrologic behavior reveals interrelationships between soil moisture and shallow groundwater, and their combined influence on runoff at the catchment outlet. This work provides new insights on links between the spatiotemporal variability

  1. Microbial responses to changes in flow status in temporary headwater streams: a cross-system comparison

    PubMed Central

    Febria, Catherine M.; Hosen, Jacob D.; Crump, Byron C.; Palmer, Margaret A.; Williams, D. Dudley

    2015-01-01

    Microbial communities are responsible for the bulk of biogeochemical processing in temporary headwater streams, yet there is still relatively little known about how community structure and function respond to periodic drying. Moreover, the ability to sample temporary habitats can be a logistical challenge due to the limited capability to measure and predict the timing, intensity and frequency of wet-dry events. Unsurprisingly, published datasets on microbial community structure and function are limited in scope and temporal resolution and vary widely in the molecular methods applied. We compared environmental and microbial community datasets for permanent and temporary tributaries of two different North American headwater stream systems: Speed River (Ontario, Canada) and Parkers Creek (Maryland, USA). We explored whether taxonomic diversity and community composition were altered as a result of flow permanence and compared community composition amongst streams using different 16S microbial community methods (i.e., T-RFLP and Illumina MiSeq). Contrary to our hypotheses, and irrespective of method, community composition did not respond strongly to drying. In both systems, community composition was related to site rather than drying condition. Additional network analysis on the Parkers Creek dataset indicated a shift in the central microbial relationships between temporary and permanent streams. In the permanent stream at Parkers Creek, associations of methanotrophic taxa were most dominant, whereas associations with taxa from the order Nitrospirales were more dominant in the temporary stream, particularly during dry conditions. We compared these results with existing published studies from around the world and found a wide range in community responses to drying. We conclude by proposing three hypotheses that may address contradictory results and, when tested across systems, may expand understanding of the responses of microbial communities in temporary streams to

  2. Headwater sediment dynamics in a debris flow catchment constrained by high-resolution topographic surveys

    NASA Astrophysics Data System (ADS)

    Loye, Alexandre; Jaboyedoff, Michel; Theule, Joshua Isaac; Liébault, Frédéric

    2016-06-01

    Debris flows have been recognized to be linked to the amounts of material temporarily stored in torrent channels. Hence, sediment supply and storage changes from low-order channels of the Manival catchment, a small tributary valley with an active torrent system located exclusively in sedimentary rocks of the Chartreuse Massif (French Alps), were surveyed periodically for 16 months using terrestrial laser scanning (TLS) to study the coupling between sediment dynamics and torrent responses in terms of debris flow events, which occurred twice during the monitoring period. Sediment transfer in the main torrent was monitored with cross-section surveys. Sediment budgets were generated seasonally using sequential TLS data differencing and morphological extrapolations. Debris production depends strongly on rockfall occurring during the winter-early spring season, following a power law distribution for volumes of rockfall events above 0.1 m3, while hillslope sediment reworking dominates debris recharge in spring and autumn, which shows effective hillslope-channel coupling. The occurrence of both debris flow events that occurred during the monitoring was linked to recharge from previous debris pulses coming from the hillside and from bedload transfer. Headwater debris sources display an ambiguous behaviour in sediment transfer: low geomorphic activity occurred in the production zone, despite rainstorms inducing debris flows in the torrent; still, a general reactivation of sediment transport in headwater channels was observed in autumn without new debris supply, suggesting that the stored debris was not exhausted. The seasonal cycle of sediment yield seems to depend not only on debris supply and runoff (flow capacity) but also on geomorphic conditions that destabilize remnant debris stocks. This study shows that monitoring the changes within a torrent's in-channel storage and its debris supply can improve knowledge on recharge thresholds leading to debris flow.

  3. Investigating thickness and physical properties of forest soil along headwater hillslopes by hole drilling method

    NASA Astrophysics Data System (ADS)

    Han, Xiaole; Liu, Jintao

    2015-04-01

    Mountain torrents along headwater hillslopes usually occur during heavy rainfall and bring damage to people's lives and properties. Thus, the mechanism for flood generation process in mountain areas must be well studied. Soil acts as an important factor controlling this process. However, systematic studies the spatial distribution of soil properties, including soil thickness, bulky density, texture and infiltration rate along headwater hillslopes are rarely obtained. Therefore, the objective of this study is to explore the variation trend of these soil properties in a 3-D perspective. To do this, a total of 39 probe measurements were made by using a 70-mm-diameter gasoline vibrating drill in a small catchment (0.42 hectare). Measurements were made by push the gasoline drill into the soil until the bedrock was encounted. Then, the drill was pushed out from the soil and the undisturbed soil was obtained. The main results of the experiment show that: (a) soil thickness decreased significantly from the valley to the ridge (e.g., the maximum soil thickness in the valley and ridge are 164cm and 81 cm, respectively). (b)Vertically, taking borehole #1 as an example (148cm deep), the saturated hydraulic conductivity decreased significantly from 1.5 mm/min (0cm deep) to 0.01 mm/min (140cm deep). Spatially, the saturated hydraulic conductivity at same depth increased with the elevation increasing. (c) Particle size analysis indicated that the soil clay content increased with increasing sampling depth. To conclude, our study reveals the spatial distribution of soil properties which can help us to explore flowpaths and store in three-dimensional at hillslope scale and develop a parsimonious 3-D physics-based model to simulate hillslope hydrological response.

  4. The Age of Terrestrial Carbon Export and Rainfall Intensity in a Temperate River Headwater System

    NASA Astrophysics Data System (ADS)

    Tittel, J.; Büttner, O.; Freier, K.; Heiser, A.; Sudbrack, R.; Ollesch, G.

    2013-12-01

    Riverine dissolved organic carbon (DOC) supports the production of estuaries and coastal ecosystems, constituting one of the most actively recycled pools of the global carbon cycle. A substantial proportion of DOC entering oceans is highly aged, but its origins remain unclear. Significant fluxes of old DOC have never been observed in temperate headwaters where terrestrial imports take place. Here, we studied the radiocarbon age of DOC in three streams draining forested headwater catchments of the river Mulde (Ore Mountains, Germany). We found modern DOC at moderately dry and moderately wet conditions as well as at high discharges during snowmelt. Old groundwater carbon contributed to stream DOC during the summer drought, although the yield was negligible. However, in a four-week summer precipitation event DOC aged at between 160 and 270 years was delivered into the watershed. In one stream, the DOC was modern but depleted in radiocarbon compared to other hydrological conditions. The yield was substantial and corresponded to 20 to 52% of the annual DOC yields in wet and dry years, respectively. Time-integrating samples of a downstream reservoir also revealed modern DOC ages under moderate conditions and old DOC from the rainfall event. Earlier studies suggested that increasing precipitation escalates the contribution of modern DOC from topsoil layers to surface runoff. Our results demonstrate a step change occurring if rainfall intensities increase and become extreme; then the consequences lead to the mobilization of old carbon in exceptionally high concentrations. The runoff/precipitation ratios of rainfall events indicated that during extreme events upland areas of the catchments were hydrologically connected to the stream and upland DOC was activated. Furthermore, the analysis of long-term data suggested that the DOC export in extreme precipitation events added to the annual yield and was not compensated for by lower exports in remaining periods. We conclude that

  5. Glacial geology of the Shingobee River headwaters area, north-central Minnesota

    USGS Publications Warehouse

    Melchior, Robert C.

    2014-01-01

    During middle and late Wisconsin time in the Shingobee River headwaters area, the Laurentide Wadena lobe, Hewitt and Itasca phases, produced terminal and ground moraine along with a variety of associated glacial features. The stratigraphic record is accessible and provides details of depositional mode as well as principal glacial events during the advance and retreat of middle and late Wisconsin ice tongues. Geomorphic features such as tunnel valleys, stream terraces, and postglacial stream cuts formed by erosional events persist to the present day. Middle Wisconsin Hewitt phase deposits are the oldest and include drumlins, ground moraine, boulder pavements, and outwash. Together, these deposits suggest a wet-based, periodically surging glacier in a subpolar thermal state. Regional permafrost and deposition from retreating ice are inferred between the end of the Hewitt phase and the advance of late Wisconsin Itasca phase ice. Itasca phase glaciation occurred as a contemporaneous pair of adjacent ice tongues whose contrasting moraine styles suggest independent flow modes. The western (Shingobee) portion of the Itasca moraine contains composite ridges, permafrost phenomena, hill-hole pairs, and debris flows. By contrast, eastern (Onigum) moraine deposits generally lack glaciotectonic features and consist almost exclusively of mud and debris flows. Near the end of the Itasca phase, large-scale hill-hole pairs developed in the Shingobee division, and debris flows from the Onigum division blocked the preexisting Shingobee tunnel valley to form glacial lake Willobee. Postglacial streams formed deep valleys as glacial lake Willobee catastrophically drained. Dates based on temperature trends in Greenland ice cores are proposed for prominent glacial events in the Shingobee area. This report proposes that Hewitt phase glaciation occurred between 27.2 and 23.6 kiloannum and Itasca phase glaciation between 22.8 and 14.7 kiloannum. Des Moines lobe (Younger Dryas) glaciation

  6. Predicting spatial distribution of postfire debris flows and potential consequences for native trout in headwater streams

    USGS Publications Warehouse

    Sedell, Edwin R; Gresswell, Bob; McMahon, Thomas E.

    2015-01-01

    Habitat fragmentation and degradation and invasion of nonnative species have restricted the distribution of native trout. Many trout populations are limited to headwater streams where negative effects of predicted climate change, including reduced stream flow and increased risk of catastrophic fires, may further jeopardize their persistence. Headwater streams in steep terrain are especially susceptible to disturbance associated with postfire debris flows, which have led to local extirpation of trout populations in some systems. We conducted a reach-scale spatial analysis of debris-flow risk among 11 high-elevation watersheds of the Colorado Rocky Mountains occupied by isolated populations of Colorado River Cutthroat Trout (Oncorhynchus clarkii pleuriticus). Stream reaches at high risk of disturbance by postfire debris flow were identified with the aid of a qualitative model based on 4 primary initiating and transport factors (hillslope gradient, flow accumulation pathways, channel gradient, and valley confinement). This model was coupled with a spatially continuous survey of trout distributions in these stream networks to assess the predicted extent of trout population disturbances related to debris flows. In the study systems, debris-flow potential was highest in the lower and middle reaches of most watersheds. Colorado River Cutthroat Trout occurred in areas of high postfire debris-flow risk, but they were never restricted to those areas. Postfire debris flows could extirpate trout from local reaches in these watersheds, but trout populations occupy refugia that should allow recolonization of interconnected, downstream reaches. Specific results of our study may not be universally applicable, but our risk assessment approach can be applied to assess postfire debris-flow risk for stream reaches in other watersheds.

  7. Agriculture has changed the amount and composition of dissolved organic matter in Central European headwater streams.

    PubMed

    Graeber, Daniel; Gelbrecht, Jörg; Pusch, Martin T; Anlanger, Christine; von Schiller, Daniel

    2012-11-01

    Dissolved organic matter (DOM) is an important part of the global carbon cycle and significantly influences aquatic ecosystem functions. Recent studies suggest that its amount and composition in freshwaters may be altered by agricultural land use, whereby the influence of preceding in-stream production and processing is not clear. To assess the land use effect on DOM amount and composition for the export from terrestrial to freshwater systems at the land-water interface, we sampled headwater streams draining agricultural and near-pristine catchments (forested and wetland) in the North German plains. To account for spatial and seasonal variation, we conducted a screening of DOM amount (53 sites) and composition (42 sites), and conducted bi-weekly samplings to investigate seasonal variation at eight sites over one year. Concentrations of dissolved organic carbon (DOC) were significantly higher for agricultural and wetland catchments than for forested catchments. Moreover, DOC loads exhibited higher seasonal variation for agricultural and wetland catchments than for forested catchments, which was due to higher variation in discharge. Parallel Factor Analysis revealed that the composition of DOM in agricultural catchments was significantly different from the other studied catchment types, and was characterized by low redox state and high structural complexity. Moreover, a gradient from protein- to humic-like fluorescence significantly separated forested from agricultural and wetland catchments. The contribution of humic-like DOM was strongly and positively related to DOC concentration, suggesting a mechanistic coupling of both. The effects of land use on patterns of DOC concentration and DOM composition were consistent across seasons, implying that land use strongly regulates DOM export. Overall, this study clearly shows the seasonally independent importance of agricultural land use for the amount and composition of DOM fluxes from the terrestrial zone to surface

  8. A hydrologic connectivity index for jurisdictional analysis of headwater streams in a montane watershed.

    PubMed

    Caruso, Brian S

    2015-10-01

    A hydrologic connectivity index (HCI) was developed to aid the US Clean Water Act Section 404 jurisdictional evaluation of headwater streams in montane watersheds, using the Cement Creek Watershed in the San Juan Mountains, Colorado as a case study. Jurisdictional determinations are required for many intermittent and ephemeral streams, where significant nexus with downstream traditional navigable waters (TNWs) must be evaluated. Three biophysical metrics (a streamflow metric, distance from the stream to the TNW, and slope between the stream and the TNW) for 239 streams in the watershed were used to develop three indices. These were then combined to develop the HCI, which is a compound, additive index. There was a large range of HCI values for ephemeral streams, which all require a significant nexus evaluation to determine jurisdiction. Statistical analysis of HCI values across stream duration and order classes showed that mean values differed significantly among classes. The flow index component constituted the greatest proportion of the HCI for perennial streams, was sensitive to the flow metrics used, and was greatest for high flows. Although ephemeral streams are only connected to the TNW less than 3 months of the year, the cumulative average annual flow contribution of ephemeral first-order streams can be 5% of the total to the TNW, and their flow contribution is larger during high flows. Some ephemeral streams with high HCI values are farthest from the TNW but contribute the greatest flow out of all ephemeral reaches, and may have significant nexus with the river. The study shows that the HCI can be useful for initial evaluation of connectivity, significant nexus, and jurisdiction of headwaters at the watershed scale.

  9. San Mateo Creek Basin

    EPA Pesticide Factsheets

    The San Mateo Creek Basin comprises approximately 321 square miles within the Rio San Jose drainage basin in McKinley and Cibola counties, New Mexico. This basin is located within the Grants Mining District (GMD).

  10. Development and Application of a Simple Hydrogeomorphic Model for Headwater Catchments

    EPA Science Inventory

    We developed a catchment model based on a hydrogeomorphic concept that simulates discharge from channel-riparian complexes, zero-order basins (ZOB, basins ZB and FA), and hillslopes. Multitank models simulate ZOB and hillslope hydrological response, while kinematic wave models pr...

  11. Evaluation of the Life History of Native Salmonids in the Malheur River Basin; Cooperative Bull Trout/Redband Trout Research Project, 1999-2000 Annual Report.

    SciTech Connect

    Schwabe, Lawrence; Tiley, Mark; Perkins, Raymond R.

    2000-11-01

    The purpose of this study is to document the seasonal distribution of adult/sub-adult bull trout (Salvelinus confluentus) in the Malheur River basin. Due to the decline of bull trout in the Columbia Basin, the United States Fish and Wildlife Service listed bull trout as a threatened species in June 1998. Past land management activities; construction of dams; and fish eradication projects in the North Fork and Middle Fork Malheur River by poisoning have worked in concert to cumulatively impact native species in the Malheur Basin (Bowers et. al. 1993). Survival of the remaining bull trout populations is severely threatened (Buchanan 1997). 1999 Research Objects are: (1) Document the migratory patterns of adult/sub-adult bull trout in the North Fork Malheur River; (2) Determine the seasonal bull trout use of Beulah Reservoir and bull trout entrainment; and (3) Timing and location of bull trout spawning in the North Fork Malheur River basin. The study area includes the Malheur basin from the mouth of the Malheur River located near Ontario, Oregon to the headwaters of the North Fork Malheur River (Map 1). All fish collected and most of the telemetry effort was done on the North Fork Malheur River subbasin (Map 2). Fish collection was conducted on the North Fork Malheur River at the tailwaters of Beulah Reservoir (RK 29), Beulah Reservoir (RK 29-RK 33), and in the North Fork Malheur River at Crane Crossing (RK 69) to the headwaters of the North Fork Malheur. Radio telemetry was done from the mouth of the Malheur River in Ontario, Oregon to the headwaters of the North Fork Malheur. This report will reflect all migration data collected from 3/1/99 to 12/31/99.

  12. Effects of Reservoirs on Nutrient Concentrations and Ratios along the Longitudinal Gradient of Danube River Basin

    NASA Astrophysics Data System (ADS)

    Salcedo Borda, J. S.; Gettel, G. M.; Irvine, K.

    2015-12-01

    Reservoirs reduce water flow and increase the retention time which can provide conditions to increase primary production, sedimentation and nutrient retention. As a consequence, nutrient ratios and fluxes of nitrogen (N), phosphorus (P), and silica (Si) may be altered which in turn affects the identity of limiting nutrients and the dynamics of primary production in downstream ecosystems. Residence time as well as the position of reservoirs along the longitudinal gradient (headwaters vs. mouth) may affect these processes. The Danube River Basin is one example where reservoirs have likely altered nutrient stoichiometry along the longitudinal gradient. It has a dam every 17 Km in the upper 1000 km of the river along with a very large dam complex (Iron Gates Dam) 117- Km from the mouth. There has been there has been an observed decline in Si flux, which may have led to changes in phytoplankton community structure in the Black Sea, but for which the causes for this decline are not yet clear. The purpose of this study is to examine the effects of reservoirs from headwaters to the mouth on nutrient stoichiometry in the Danube Basin. Data on dissolved Si, N, and P concentrations from 1996 to 2012 were analyzed from 40 monitoring stations from the TransNational Monitoring Network (TNMN), which are located in the main stem of the Danube. Time series analysis is used to compare nutrient concentrations and ratios both through seasons and through the 15 year time-period. The monitoring stations are located above and below reservoirs in order to analyze the effect of reservoirs on nutrient ratios and fluxes. Preliminary results show that relationship of dissolved inorganic N (DIN): soluble reactive P (SRP) range from 207 to 76, while DIN:Si ratio ranges from 1.89 to 0.2 from the headwaters to the mouth.

  13. Constraints upon the Response of Fish and Crayfish to Environmental Flow Releases in a Regulated Headwater Stream Network

    PubMed Central

    Chester, Edwin T.; Matthews, Ty G.; Howson, Travis J.; Johnston, Kerrylyn; Mackie, Jonathon K.; Strachan, Scott R.; Robson, Belinda J.

    2014-01-01

    In dry climate zones, headwater streams are often regulated for water extraction causing intermittency in perennial streams and prolonged drying in intermittent streams. Regulation thereby reduces aquatic habitat downstream of weirs that also form barriers to migration by stream fauna. Environmental flow releases may restore streamflow in rivers, but are rarely applied to headwaters. We sampled fish and crayfish in four regulated headwater streams before and after the release of summer-autumn environmental flows, and in four nearby unregulated streams, to determine whether their abundances increased in response to flow releases. Historical data of fish and crayfish occurrence spanning a 30 year period was compared with contemporary data (electrofishing surveys, Victoria Range, Australia; summer 2008 to summer 2010) to assess the longer–term effects of regulation and drought. Although fish were recorded in regulated streams before 1996, they were not recorded in the present study upstream or downstream of weirs despite recent flow releases. Crayfish (Geocharax sp. nov. 1) remained in the regulated streams throughout the study, but did not become more abundant in response to flow releases. In contrast, native fish (Gadopsis marmoratus, Galaxias oliros, Galaxias maculatus) and crayfish remained present in unregulated streams, despite prolonged drought conditions during 2006–2010, and the assemblages of each of these streams remained essentially unchanged over the 30 year period. Flow release volumes may have been too small or have operated for an insufficient time to allow fish to recolonise regulated streams. Barriers to dispersal may also be preventing recolonisation. Indefinite continuation of annual flow releases, that prevent the unnatural cessation of flow caused by weirs, may eventually facilitate upstream movement of fish and crayfish in regulated channels; but other human–made dispersal barriers downstream need to be identified and ameliorated, to allow

  14. Constraints upon the response of fish and crayfish to environmental flow releases in a regulated headwater stream network.

    PubMed

    Chester, Edwin T; Matthews, Ty G; Howson, Travis J; Johnston, Kerrylyn; Mackie, Jonathon K; Strachan, Scott R; Robson, Belinda J

    2014-01-01

    In dry climate zones, headwater streams are often regulated for water extraction causing intermittency in perennial streams and prolonged drying in intermittent streams. Regulation thereby reduces aquatic habitat downstream of weirs that also form barriers to migration by stream fauna. Environmental flow releases may restore streamflow in rivers, but are rarely applied to headwaters. We sampled fish and crayfish in four regulated headwater streams before and after the release of summer-autumn environmental flows, and in four nearby unregulated streams, to determine whether their abundances increased in response to flow releases. Historical data of fish and crayfish occurrence spanning a 30 year period was compared with contemporary data (electrofishing surveys, Victoria Range, Australia; summer 2008 to summer 2010) to assess the longer-term effects of regulation and drought. Although fish were recorded in regulated streams before 1996, they were not recorded in the present study upstream or downstream of weirs despite recent flow releases. Crayfish (Geocharax sp. nov. 1) remained in the regulated streams throughout the study, but did not become more abundant in response to flow releases. In contrast, native fish (Gadopsis marmoratus, Galaxias oliros, Galaxias maculatus) and crayfish remained present in unregulated streams, despite prolonged drought conditions during 2006-2010, and the assemblages of each of these streams remained essentially unchanged over the 30 year period. Flow release volumes may have been too small or have operated for an insufficient time to allow fish to recolonise regulated streams. Barriers to dispersal may also be preventing recolonisation. Indefinite continuation of annual flow releases, that prevent the unnatural cessation of flow caused by weirs, may eventually facilitate upstream movement of fish and crayfish in regulated channels; but other human-made dispersal barriers downstream need to be identified and ameliorated, to allow

  15. Mean transit times in contrasting headwater catchments from southeast Australia determined using Tritium

    NASA Astrophysics Data System (ADS)

    Cartwright, Ian; Morgenstern, Uwe; Irvine, Dylan

    2016-04-01

    Headwater streams contribute a significant proportion of the total discharge of many river systems. However, despite their importance, the time taken for rainfall to pass through the catchment into the streams (the transit time) in headwater catchments is largely unknown as are the catchment characteristics (such as drainage density, topography, landuse, or geology) that determine variations in transit times. Because the peak in Tritium activities in rainfall produced by atmospheric nuclear tests in the1950's and 1960's (the "bomb-pulse") was several orders of magnitude lower in the southern hemisphere than in the northern hemisphere, Tritium activities of remnant bomb pulse water in the southern hemisphere have decayed below those of modern rainfall. This allows mean transit times to be estimated from single Tritium measurements. Here we use Tritium to estimate transit times of water contributing to perennial streams in the adjacent upper catchments of the Yarra and Latrobe Rivers (southeast Australia). Samples were collected at varying flow from six headwater tributary sites in the Latrobe catchment, which is largely forested and four tributaries in the Yarra catchment which has been extensively cleared for dryland agriculture. The lowest Tritium activities were recorded during summer baseflow conditions and are between 1.25 and 1.75 TU, these are significantly below the Tritium activity of local rainfall (~2.8 TU). Mean transit times calculated using an exponential-piston flow lumped parameter model are 21 to 47 years. Tritium activities during the recession periods following winter high flows are higher (1.54 to 2.1 TU), which may reflect either the dilution of a baseflow component with recent surface runoff or mobilisation of different stores of water with different residence times (e.g., from the soils or the regolith) from within the catchment. The variation of major ion concentrations with discharge suggests it is more likely that that different stores of

  16. Benthic invertebrate assemblages and their relation to physical and chemical characteristics of streams in the Eastern Iowa Basins, 1996-98

    USGS Publications Warehouse

    Brigham, Allison R.; Sadorf, Eric M.

    2001-01-01

    Stream size, a reflection of basin area, was a principal influence in categorizing the benthic invertebrate assemblages, with sites that have the largest basin areas forming a separate group. Although it is difficult to distinguish among the contributions of large basin area, increased concentrations of nutrients and pesticides, and decreasing instream habitat diversity, the resulting invertebrate assemblage described was distinct. The remaining sites were headwater or tributary streams that reflected conditions more common to smaller streams, such as higher gradients and the potential for more diverse or extensive riparian habitat, but were distinguished by landform. Following basin area in importance, landform contributed to the differences observed among the benthic invertebrate communities at the remaining sites.

  17. Understanding drivers of the export of dissolved organic carbon from headwater catchments in Germany using Generalised Additive Models

    NASA Astrophysics Data System (ADS)

    Selle, Benny; Tittel, Jörg; Musolff, Andreas

    2015-04-01

    In the literature, several causes of recently increasing concentrations of dissolved organic carbon (DOC) in headwaters across eastern North America and northern and central Europe have been debated. One likely driver of the widespread increase of DOC concentrations since the early to mid 1990s are decreasing depositions of acid rain resulting in an increased solubility of organic carbon compounds including humic acids. Here, we tested the hypothesis if the reduced availability of both nitrate and sulfate stimulated the reduction of ferric iron soil minerals and the mobilisation of DOC. Decreasing depositions often resulted in a reduced availability of both nitrate and sulphate, which are preferred electron acceptors in microbial decomposition processes. As iron minerals act as efficient sorbents of organic compounds in soils its reduction may have caused a release of humic substances and hence an increasing export of DOC from headwater catchments. To test this hypothesis, time series of DOC, dissolved iron, sulfate and nitrate from several German headwater catchments were examined using Generalised Additive Models. Using this modelling technique, discharge corrected time series of concentrations were represented as a sum of a seasonal and a non-linear trend component. Both, the computed trends and seasonalities supported the redox hypothesis.

  18. Effects of insect and decapod exclusion and leaf litter species identity on breakdown rates in a tropical headwater stream.

    PubMed

    Rincón, José; Covich, Alan

    2014-04-01

    High species richness of tropical riparian trees influences the diversity of organic detritus entering streams, creating temporal variability in litter quantity and quality. We examined the influence of species of riparian plants and macroinvertebrate exclusion on leaf-litter breakdown in a headwater stream in the Luquillo Mountains of Puerto Rico. Leaf litter of Dacryodes excelsa (Burseraceae), Guarea guidonia (Meliaceae), Cecropia scheberiana (Moraceae), Manilkara bidentata (Sapotaceae), and Prestoea acuminata (Palmae) were incubated in litter bags in a pool of Quebrada Prieta. Fine mesh bags were used to exclude macroinvertebrates during leaf breakdown, and coarse mesh bags allowed access to decapod crustaceans (juvenile shrimps and crabs) and aquatic insects (mainly mayflies, chironomids, and caddisflies). D. excelsa and G. guidonia (in coarse- and fine-mesh bags) had significantly higher breakdown rates than C. scheberiana, M. bidentata, and P. acuminata. Breakdown rates were significantly faster in coarse-mesh bag treatments for all leaf types, thus indicating a positive contribution of macroinvertebrates in leaf litter breakdown in this headwater stream. After 42 days of incubation, densities of total invertebrates, mayflies and caddisflies, were higher in bags with D. excelsa and G. guidonia, and lower in P. acuminata, C. scheberiana y M. bidentata. Decay rates were positively correlated to insect densities. Our study highlights the importance of leaf identity and macroinvertebrate exclusion on the process of leaf litter breakdown in tropical headwater streams.

  19. Prediction of glacier melt and runoff for a high-altitude headwater catchment in Bolivian Andes

    NASA Astrophysics Data System (ADS)

    Liu, T.; Kinouchi, T.; Mendoza, J.; Asaoka, Y.

    2013-12-01

    In Andes, retreat of tropical glaciers is rapid, thus water resources currently available from glacierized catchments would be changed in its volume and temporal variations due to climate change and glacier shrinkage. Water resources in La Paz and El Alto, Bolivia, strongly depend on the runoff from glacierized headwater catchments in the Cordillera Real, Andes, which is a combined contribution from glacier and snow melts in glacierized areas and surface and subsurface runoff due to snowmelt and rainfall in non-glacierized areas. To predict long-term availability of water resources from glacierized catchments in the Cordillera Real, we developed a semi-distributed conceptual glacio-hydrological model applicable for the partially glacierized catchments in high mountains by considering different phases of precipitation, various runoff components from glacierized and non-glacierized areas, the retarding effect by lakes and wetlands, and the change of glacierized areas based on the area-volume relationship. The model was successfully applied to the Huayna West headwater catchment located in the Cordillera Real, Bolivian Andes, for the period of June 2011 to May 2013, after calibrating by observed meteorological and hydrological conditions. Our results indicate that the glacier melt is enhanced during two transition periods, i.e. from the dry to wet season (October to early December) and the wet to dry season (March to May), while the surface runoff from snowmelt and subsurface runoff are more dominant between the two periods from December to February. It was found that the simulated runoff was highly sensible to spatial and temporal variation of air temperature, and smoothed by the subsurface flow and retarding processes in lakes and wetlands. We predicted the change of glacierized area and runoff until 2050 under different climate scenarios, which indicates that the glacier continues to shrink by 2050 resulting in the areal reduction ranging from 65% to 73% and

  20. Seasonal variation of glacial melt proportion in the headwaters of the Ganges River: Preliminary results

    NASA Astrophysics Data System (ADS)

    Sen, Indra; Hemingway, Jordon; Sengupta, Deep; Sinha, Rajiv; Peucker-Ehrenbrink, Bernhard; Chakraborty, Anirban

    2015-04-01

    The effect of global warming on Hindu Kush- Himalayan (HKH) glaciers is of global concern as they are the source of many large rivers in the Indian subcontinent such as the Indus, Ganges, and Brahmaputra. Questions and concerns have been raised about the melting of the Himalayan glaciers, and how this will impact downstream water supplies, hydropower generation, irrigation, and food security issues. Of all the HKH glaciers, the Gangotri glacier located in the Uttarkashi district of the Garhwal Himalaya, India has received special attention as it is receding at an alarming rate of 30 m/year. The Gangotri glacier feeds the Ganges River, which drains nearly 1 million square kilometers of land surface in India and Bangladesh, and provides water security to half a billion people. Based on remote sensing data it has been estimated that the overall area of Gangotri glacier has shrunk by 6% between 1952 and 2006, and that the glacial terminus has receded by more than 850 m over the past 25 years. However, ground observation data aimed at studying the changing influence of the Gangotri glacier on the discharge of the Ganges River are still limited. Here we report preliminary observations of physical (temperature and conductivity) and chemical (major ion and trace element concentrations, pH, and dissolved oxygen) parameters of water samples near glaciated Ganges headwaters for the pre-monsoon (May), monsoon (August), and post monsoon (November) periods corresponding to 2014. We have characterized the seasonal δ18O and δ2H variability of the Ganges headwaters. The pre-monsoonal δ18O varied between -15.1o and -9.3o whereas the monsoonal δ18O varied between -14.9o and -5.7o. The pre-monsoon δ2H varied between -105.4o and -61.5o, whereas the monsoonal δ2H varied between -103.8o and -47.2o. Our isotope-mixing model predicts significant seasonal (pre-monsoon, monsoon and post-monsoon) variability of glacial melt contributions to the total discharge. Water chemistry data also

  1. Impacts of Surrounding Land Cover on Headwater Wetland Edaphic Habitat Types and Their Associated Microbial Communities

    NASA Astrophysics Data System (ADS)

    Moon, J. B.; Wardrop, D. H.; Smithwick, E. A.

    2010-12-01

    Although small in size, headwater wetland complexes provide a disproportionate share of microbially mediated ecosystem services to the surrounding landscape and hydroscape. Two services that are of current interest to scientists and managers, given their role in regulating climate and water quality, are the retention and transformation of carbon and nitrogen pools. Although it is the wetland complex’s geographic position between the landscape and hydroscape that creates these hotspots of ecosystem function, continuous shifts in the surrounding scapes can also affect the complex’s transformational capacity through changes to its natural hydrologic disturbance regime and subsequent material fluxes. We have begun to investigate the influence of surrounding land cover and associated differences in hydrology on wetland edaphic habitats and their associated microbial communities. These studies are taking place in wetland complexes located in the headwaters of the Chesapeake Bay Watershed, within the Ridge and Valley Region of central Pennsylvania. Within this region, surrounding land cover ranges from intact forested buffers to a matrix of land cover types (e.g., mixed forest, grassland, and impermeable surfaces). Over a preliminary six-month collection period we found higher frequency and intensity of hydrologic fluctuations in wetlands surrounded by a matrix of land cover types, compared to highly stable saturated conditions of wetland complexes with intact forested buffers. Differences were also found in both the abundances of edaphic habitats as well as in the types of habitats present within these surrounding land cover groups. Wetlands with intact forested buffers had (1) fresh organic residue soils with high overall microbial biomasses and relatively high abundances of microeukaryotic groups, (2) reduced muck soils with relatively large proportions of branched fatty acid microbial groups, and (3) carbon and nutrient depleted sandy mineral soils with relatively

  2. Active Stream Length Dynamics in Headwater Catchments Spanning Physiographic Provinces in the Appalachian Highlands

    NASA Astrophysics Data System (ADS)

    Jensen, C.; McGuire, K. J.

    2015-12-01

    One of the most basic descriptions of streams is the presence of channelized flow. However, this seemingly simple query goes unanswered for the majority of headwater networks, as stream length expands and contracts with the wetness of catchments seasonally, interannually, and in response to storm events. Although streams are known to grow and shrink, a lack of information on longitudinal dynamics across different geographic regions precludes effective management. Understanding the temporal variation in temporary network length over a broad range of settings is critical for policy decisions that impact aquatic ecosystem health. This project characterizes changes in active stream length for forested headwater catchments spanning four physiographic provinces of the Appalachian Highlands: the New England at Hubbard Brook Experimental Forest, New Hampshire; Valley and Ridge at Poverty Creek and the North Fork of Big Stony Creek in Jefferson National Forest, Virginia; Blue Ridge at Coweeta Hydrologic Laboratory, North Carolina; and Appalachian Plateau at Fernow Experimental Forest, West Virginia. Multivariate statistical analysis confirms these provinces exhibit characteristic topographies reflecting differences in climate, geology, and environmental history and, thus, merit separate consideration. The active streams of three watersheds (<45 ha) in each study area were mapped six times to capture a variety of moderate flow conditions that can be expected most of the time (i.e., exceedance probabilities between 25 to 75%). The geomorphic channel and channel heads were additionally mapped to determine how active stream length variability relates to the development of the geomorphic network. We found that drainage density can vary up to four-fold with discharge. Stream contraction primarily proceeds by increasing disconnection and disintegration into pools, while the number of flow origins remains constant except at high and low extremes of discharge. This work demonstrates

  3. Tracing bed load sediment using PIT tags in a steep headwater channel.

    NASA Astrophysics Data System (ADS)

    Kubo, Y.; Hiraoka, M.; Gomi, T.; Nidaira, K.; Uchiyama, Y.

    2015-12-01

    Bed load transport in steep headwater channels is complex because of the particle size distribution, topography, channel roughness, and sediment supply from adjacent hillslope. We monitored movement bed load sediment using PIT tags in a steep headwater channel segments. Study area is located in 7.0ha Oobora-sawa observatory from 50km west of Tokyo metropolitan. Annual precipitation is 3000mm and mean temperature is 10°. Annual bed load sediment yields in the study catchment was from 6.5 to 7.6 t/ha/yr. Mean channel gradient is 24° with 0.5m low flow width. The channel is consisted by 0.2 to 1.6m interval of step-pool sequences. Based on pebble count method, D10, D50 and D90 of channel substrate were 8, 28 and 206mm respectively. We deployed 134 bed load tracers with five classes of diameter ranges (Class1:17.7, Class2:24.8, Class3:35.8, Class4:54.1 and Class5:83.8mm). Selected tracers represented from D20 to D77 of channel bed substrates. PIT tags (diameter 2mm, length 9mm and weight 0.1g) were placed into the particles by drilling and refilled with non-corrosive epoxy. We investigated the movement of bed load tracers every major storm event since February 2015. Channel morphology was measured using photographic survey and topographic model was developed using software of Surface from motion (PhotoScan). Mean bed load movement in the 5 storm event with 438 mm total and 33 mm maximum intensity was 168 mm. Then 51 mm of bed load movement occurred in 43 mm total and 16 mm intensity of rainfall. Recurrence interval of the two storm event was 1 and 4 year respectively. Receivable rates of bed load tracers was 70 and 74 % in the two events. Mobilized bed load (7 to 18%) deposited at cascade, pool and riffle, and among step clusters. Mobilized bed load tracers is rather random and we do not find any patterns for particle size for the movement and distance. Our field monitoring showed that bed load tracers were not mobilized for storm events with 10.5mm/h intensity of

  4. Rainfall infiltration process in mountain headwater region using electrical resistivity tomography

    NASA Astrophysics Data System (ADS)

    Ono, M.; Yamamiya, K.; Shimada, J.

    2008-12-01

    Many researchers have studied about the hydrological process, especially rainfall-runoff process, in the headwater region using multi hydrometric methods. Since the possibility has been recognized that bedrock groundwater has important role to play in the rainfall-runoff process, it is important to comprehend the rainfall infiltration process within fluctuations of bedrock groundwater. However, we would need many hydrological instruments to understand this process precisely. So we have applied electrical resistivity tomography (ERT) method to understand rainfall infiltration process in the area that is estimated the contribution of bedrock groundwater for rainfall-runoff processes. Resistivity changes with the saturation rate of the pore fluid in the subsurface material. So it is possible to estimate spatial and temporal distribution of subsurface water by using ERT. In this study, we will estimate rainfall infiltration process in mountain headwater region using resistivity method. The study area is the Mamushi-dani watershed in Shiranui, Kumamoto, Japan. We described the bedrock groundwater storage systems using resistivity method in this watershed previously. Resistivity has been observed at 2 measurement lines in slope areas of this watershed. Both measurement lines have 47m in length, 1m electrode spacing and 48 electrodes. We used the multi-electrode system, NEXT-400(Kowa Co. Ltd., Japan) for measuring apparent resistivity and the application software, E-tomo (Diaconsultant Co. Ltd., Japan) for inversion of apparent resistivity data. The observed resistivity data were compared with water head observed at borehole and specific discharge observed at foot of the watershed. Inverted resistivity profiles and observed hydrological data showed the interface between saturated and unsaturated zone. During rainfall occurs, resistivity in surface area gets lower than that before the rainfall and resistivity in some part of unsaturated area shows increasing tendency. Both

  5. Plio-Pleistocene drainage development in an inverted sedimentary basin: Vera basin, Betic Cordillera, SE Spain

    NASA Astrophysics Data System (ADS)

    Stokes, Martin

    2008-08-01

    The Vera basin is one of a series of interconnected Neogene-Quaternary sedimentary basins located within the Internal Zone of the Betic Cordillera (southeast Spain). Since the Pliocene the Vera basin has been subjected to low uplift rates (11-21 m Ma - 1 ) and inverted via compressive tectonics that are related to the ongoing oblique collision between the African and Iberian plates. Within this paper the sedimentary and geomorphic response to basin inversion is explored. Sedimentary processes and environments are established for key stratigraphic units of the Pliocene/Plio-Pleistocene basin fill and Pleistocene dissectional landscape. These data are subsequently utilised to reconstruct an evolving basin palaeogeography. Fault and uplift data are employed to discuss the role of tectonically driven basin inversion for controlling the resultant palaeogeographic changes and associated patterns of drainage development. During the Early-Mid Pliocene the Vera basin was characterised by shallow marine shelf conditions (Cuevas Formation). A major palaeogeographic reorganisation occurred during the Mid-Late Pliocene. Strike-slip movement along the eastern basin margin, coupled with uplift and basin emergence created a protected, partially enclosed marine embayment that was conducive for Gilbert-type fan-delta sedimentation from fluvial inputs along the northern and eastern basin margins (Espíritu Santo Formation). The Vera basin then became fully continental and internally drained through the development of a consequent drainage network that formed following the withdrawal of marine conditions during the Late Pliocene to Early Pleistocene. Alluvial fans developed along the northern and western basin margins, grading to a bajada and terminating in a playa lake in central basin areas (Salmerón Formation). During the Early-Mid Pleistocene a switch from basin infilling to dissection took place, recorded by alluvial fan incision, a switch to braided river sedimentation and

  6. Climatic Variation and River Flows in Himalayan Basins Upstream of Large Dams

    NASA Astrophysics Data System (ADS)

    Eaton, D.; Collins, D. N.

    2014-12-01

    High specific discharges from Himalayan headwater basins feed major reservoirs generating hydropower and supplying water to irrigation schemes across the Punjab plains of north-west India and Pakistan. Flow arises from seasonal winter snow cover, summer monsoon precipitation and melting glacier ice in varying proportions and differing absolute quantities along west -east axes of the Karakoram and western Himalaya. Discharge records for stations above Tarbela (Indus), Mangla (Jhelum), Marala (Chenab) and Bhakra (Sutlej) dams have been examined for periods between 1920 and 2009, together with precipitation and air temperature data for stations with long records (within the period 1893 to 2013) at elevations between 234 and 3015 m a.s.l. Ice-cover age in the basins above the dams was between 1 and 12 %. Flows in the Sutlej, Chenab and Jhelum reached maxima in the 1950s before declining to the 1970s. Flow in the Chenab and Jhelum increased to 1950s levels in the 1990s, before falling steeply into the 2000s mimicking variations in winter and monsoon precipitation. Discharge in the Indus at Tarbela increased from the 1970s, reaching a maximum in the late 1980s/early 1990s, before declining back to 1970s levels in the 2000s, flow being influenced not only by precipitation fluctuations but also by changes in air temperature affecting glacier melt in headwater basins. Runoff at Bhakra was augmented by flow from the Beas-Sutlej link canal after 1977, but natural flow in the Sutlej above Luhri reduced considerably from the 1990s influenced by declining flows in the relatively dry but large Tibetan portion of the basin area. Large year-to-year fluctuations of reservoir inflows are nonetheless based on significant sustained underlying discharge levels at all four reservoirs.

  7. Interaction of surface water and groundwater in the Nile River basin: isotopic and piezometric evidence

    NASA Astrophysics Data System (ADS)

    Kebede, Seifu; Abdalla, Osman; Sefelnasr, Ahmed; Tindimugaya, Callist; Mustafa, Osman

    2016-12-01

    Past discussions around water-resources management and development in the River Nile basin disregard groundwater resources from the equation. There is an increasing interest around factoring the groundwater resources as an integral part of the Nile Basin water resources. This is hampered by knowledge gap regarding the groundwater resources dynamics (recharge, storage, flow, quality, surface-water/groundwater interaction) at basin scale. This report provides a comprehensive analysis of the state of surface-water/groundwater interaction from the headwater to the Nile Delta region. Piezometric and isotopic (δ18O, δ2H) evidence reveal that the Nile changes from a gaining stream in the headwater regions to mostly a loosing stream in the arid lowlands of Sudan and Egypt. Specific zones of Nile water leakage to the adjacent aquifers is mapped using the two sources of evidence. Up to 50% of the surface-water flow in the equatorial region of the Nile comes from groundwater as base flow. The evidence also shows that the natural direction and rate of surface-water/groundwater interaction is largely perturbed by human activities (diversion, dam construction) particularly downstream of the Aswan High Dam in Egypt. The decrease in discharge of the Nile River along its course is attributed to leakage to the aquifers as well as to evaporative water loss from the river channel. The surface-water/groundwater interaction occurring along the Nile River and its sensitivity to infrastructure development calls for management strategies that account groundwater as an integral part of the Nile Basin resources.

  8. Stable isotope analyses of web-spinning spider assemblages along a headwater stream in Puerto Rico.

    PubMed

    Kelly, Sean P; Cuevas, Elvira; Ramírez, Alonso

    2015-01-01

    Web-spinning spiders that inhabit stream channels are considered specialists of aquatic ecosystems and are major consumers of emerging aquatic insects, while other spider taxa are more commonly found in riparian forests and as a result may consume more terrestrial insects. To determine if there was a difference in spider taxa abundance between riverine web-spinning spider assemblages within the stream channel and the assemblages 10 m into the riparian forest, we compared abundances for all web-spinning spiders along a headwater stream in El Yunque National Forest in northeast Puerto Rico. By using a nonmetric dimensional scaling (NMDS) abundance analysis we were able to see a clear separation of the two spider assemblages. The second objective of the study was to determine if aquatic insects contributed more to the diet of the spider assemblages closest to the stream channel and therefore stable isotope analyses of δ (15)N and δ (13)C for web-spinning spiders along with their possible prey were utilized. The results of the Bayesian mixing model (SIAR) however showed little difference in the diets of riverine (0 m), riparian (10 m) and upland (25 m) spiders. We found that aquatic insects made up ∼50% of the diet for web-spinning spiders collected at 0 m, 10 m, and 25 m from the stream. This study highlights the importance of aquatic insects as a food source for web-spinning spiders despite the taxonomic differences in assemblages at different distances from the stream.

  9. Storage controls on the generation of double peak hydrographs in a forested headwater catchment

    NASA Astrophysics Data System (ADS)

    Martínez-Carreras, Núria; Hissler, Christophe; Gourdol, Laurent; Klaus, Julian; Juilleret, Jérôme; Iffly, Jean François; Pfister, Laurent

    2016-12-01

    Double peak hydrographs are widespread phenomena but poorly understood mechanistically. In many cases, saturation-excess overland flow in the near-stream areas is assumed to control the initial peak, while the delayed peak is explained by subsurface flow in the soil or sediment cover or groundwater flow on fractured bedrock. Here we explore the mechanisms that control the generation of double peak hydrographs in a forested headwater catchment. We made use of the extensive high-resolution hydrometric time series collected in the catchment to estimate catchment storage and causal linkages. We found that double peak hydrographs occurred only after a certain amount of catchment storage was exceeded. The amount of this storage threshold was consistent over a 3-year period. The non-linear relationship between storage and discharge led to hysteretic relationships between both variables, and these hysteretic relationships were different for the different hydrograph types (single or double peak hydrographs). Discharge peaked before catchment storage during single peak hydrographs suggesting that single peaks were mainly generated by water quickly reaching the stream during precipitation pulses. It was catchment storage that peaked first during double peak hydrographs and consequently generated the delayed peak in the hydrograph. Our results also showed that double peak hydrographs were controlled in different proportions by contrasting landscape units (defined along a hillslope sequence). Hillslopes were connected to the stream at low discharge values, whereas the plateau dominated discharge generation when storage reached a certain threshold value.

  10. Diversity of Salmonella in biofilms and water in a headwater ecosystem.

    PubMed

    Sha, Qiong; Forstner, Michael R J; Hahn, Dittmar

    2013-03-01

    The diversity of Salmonella was analysed in biofilm and water samples from the spring and slough arms of Spring Lake, the headwaters of the San Marcos River, Texas, during the drought of 2011, with only one potential run-off event at the beginning of the study. Salmonellae were detected in semiselective enrichment cultures by end-point PCR during the entire sampling period of (11 sampling events during 2 months). From the spring arm site, 73% of the biofilms and 41% of the water samples were positive for salmonellae, while only 9% of the biofilms and 23% of the water samples were positive from the slough arm site. Salmonellae could be isolated from all positive samples, with higher diversity in biofilms compared with water samples and more strains obtained from the spring arm than from the slough arm. Differences between sites were generally caused by less frequently detected isolates, while the majority of isolates that were present in both biofilms and water from both sites was represented by three strains only. Quantification attempts by quantitative PCR directly in samples without prior enrichment did not result in a reliable detection of salmonellae, suggesting that numbers in all samples were below the detection limit.

  11. Macroinvertebrate Response to Drought in Undisturbed Headwater Streams of Southwest Georgia.

    NASA Astrophysics Data System (ADS)

    Winn, R. T.; Griswold, M. W.; Golladay, S. W.; Crisman, T. L.

    2005-05-01

    Macroinvertebrates were sampled in four headwater streams for two years (2001-2003) to establish baseline conditions for a study evaluating forestry best management practices. The Palmer Drought Severity Index indicated that the study site experienced a prolonged moderate to severe drought prior to study initiation, with year one of the study characterized as a moderate drought, while year two encompassed drought and initial rainfall recovery. Benthic macroinvertebrates were collected in streams during year one (December 2001/February 2002) and year two (December 2002/February 2003) using a multi-habitat sampling procedure. Individuals were identified to the lowest practical taxonomic level (mostly genus), and metrics including abundance, total number of taxa, and Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa were calculated. Repeated measures ANOVA identified differences in macroinvertebrate assemblages due to sampling period, with lower values for December 2001 relative to February 2003. Abundance and EPT taxa showed an increasing relationship with average daily flow in successive samples of the study. Initiation of drought conditions prior to the study adversely affected species composition (low numbers of EPT taxa and long lived taxa) and trophic structure (co-dominance of shredders, collectors, and predators).

  12. Stable isotope analyses of web-spinning spider assemblages along a headwater stream in Puerto Rico

    PubMed Central

    Cuevas, Elvira; Ramírez, Alonso

    2015-01-01

    Web-spinning spiders that inhabit stream channels are considered specialists of aquatic ecosystems and are major consumers of emerging aquatic insects, while other spider taxa are more commonly found in riparian forests and as a result may consume more terrestrial insects. To determine if there was a difference in spider taxa abundance between riverine web-spinning spider assemblages within the stream channel and the assemblages 10 m into the riparian forest, we compared abundances for all web-spinning spiders along a headwater stream in El Yunque National Forest in northeast Puerto Rico. By using a nonmetric dimensional scaling (NMDS) abundance analysis we were able to see a clear separation of the two spider assemblages. The second objective of the study was to determine if aquatic insects contributed more to the diet of the spider assemblages closest to the stream channel and therefore stable isotope analyses of δ15N and δ13C for web-spinning spiders along with their possible prey were utilized. The results of the Bayesian mixing model (SIAR) however showed little difference in the diets of riverine (0 m), riparian (10 m) and upland (25 m) spiders. We found that aquatic insects made up ∼50% of the diet for web-spinning spiders collected at 0 m, 10 m, and 25 m from the stream. This study highlights the importance of aquatic insects as a food source for web-spinning spiders despite the taxonomic differences in assemblages at different distances from the stream. PMID:26500830

  13. Dissolved organic matter quality and bioavailability changes across an urbanization gradient in headwater streams.

    PubMed

    Hosen, Jacob D; McDonough, Owen T; Febria, Catherine M; Palmer, Margaret A

    2014-07-15

    Landscape urbanization broadly alters watersheds and stream ecosystems, yet the impact of nonpoint source urban inputs on the quantity, quality, and ultimate fate of dissolved organic matter (DOM) is poorly understood. We assessed DOM quality and microbial bioavailability in eight first-order Coastal Plain headwater streams along a gradient of urbanization (i.e., percent watershed impervious cover); none of the streams had point source discharges. DOM quality was measured using fluorescence excitation-emission matrices (EEMs) coupled with parallel factor analysis (PARAFAC). Bioavailability was assessed using biodegradable dissolved organic carbon (BDOC) incubations. Results showed that watershed impervious cover was significantly related to stream DOM composition: increasing impervious cover was associated with decreased amounts of natural humic-like DOM and enriched amounts of anthropogenic fulvic acid-like and protein-like DOM. Microbial bioavailability of DOM was greater in urbanized streams during spring and summer, and was related to decreasing proportions of humic-like DOM and increasing proportions of protein-like DOM. Increased bioavailability was associated with elevated extracellular enzyme activity of the initial microbial community supplied to samples during BDOC incubations. These findings indicate that changes in stream DOM quality due to watershed urbanization may impact stream ecosystem metabolism and ultimately the fate of organic carbon transported through fluvial systems.

  14. Evaluating the effects of land use on headwater wetland amphibian assemblages in coastal Alabama

    USGS Publications Warehouse

    Alix, Diane M.; Anderson, Christopher J.; Grand, James B.; Guyer, Craig

    2014-01-01

    Anthropogenic land use is known to impact aquatic ecosystems in several ways, including increased frequency and intensity of floods, stream channel incision, sedimentation, and loss of microtopography. Amphibians are susceptible to changes in wetland and surrounding habitats. This study evaluated amphibian assemblages of fifteen headwater slope wetlands in coastal Alabama across a gradient of land uses. Amphibians were surveyed on a seasonal basis and land use was delineated within wetland watersheds and within a 200-m buffer surrounding each wetland. Amphibian presence/absence and land use data were used to develop species occupancy models. Both urban and agricultural land use were shown to influence amphibian occurrence. Species richness ranged from five to ten species across sites; however, five species only occurred in wetlands surrounded by forested lands. Many species were detected more frequently on these wetlands compared to wetlands surrounded by urban or mixed land uses. Occupancy models showed Acris gryllus was negatively associated with the amount of agriculture within a buffer around the wetland. Hyla squirella, Lithobates clamitans, and L. sphenocephalus were positively associated with agricultural land within a watershed. Anaxyrus terrestris and the non-native Eleutherodactylus planirostris were positively associated with the amount of impervious surface area within the wetland buffer.

  15. Morphology of step-pools in a wilderness headwater stream: The importance of standardizing geomorphic measurements

    NASA Astrophysics Data System (ADS)

    Nickolotsky, Aaron; Pavlowsky, Robert T.

    2007-01-01

    The morphology of step-pools and cascades reflect the geological and climatic factors affecting channels in mountain watersheds. This study uses longitudinal and cross-section surveys to describe a headwater stream in the Boston Mountains of the Ozarks Plateau region in Arkansas and develop morphological relationships for comparisons with other regions. In the Bowers Hollow Creek watershed (3.5 km 2), located within the boundaries of the Upper Buffalo Wilderness Area, step height and wavelength relationships are generally similar to those reported from other regions. Step-pool reaches were widely distributed in a discontinuous manner throughout the watershed. Average values of the sampled reaches are: reach slopes, 0.105 m/m; width, 6.10 m; crest particle sizes, 440 mm; step heights, 0.87 m; and step wavelengths, 6.62 m. The mean step steepness for the watershed was 0.13, whereas the mean length of a reach step to height ratio was 9:1. A comparison of morphological definitions found that the values of step height and steepness can vary by > 30% according to how step parameters are defined. Step height is particularly sensitive; thus, comparison of step height-based relationships from published data requires great care.

  16. Influence of eastern hemlock (Tsuga canadensis) forests on aquatic invertebrate assemblages in headwater streams

    USGS Publications Warehouse

    Snyder, C.D.; Young, J.A.; Lemarie, D.P.; Smith, D.R.

    2002-01-01

    We conducted a comparative study in the Delaware Water Gap National Recreation Area to determine the potential long-term impacts of hemlock forest decline on stream benthic macroinvertebrate assemblages. Hemlock forests throughout eastern North America have been declining because of the hemlock woolly adelgid, an exotic insect pest. We found aquatic invertebrate community structure to be strongly correlated with forest composition. Streams draining hemlock forests supported significantly more total taxa than streams draining mixed hardwood forests, and over 8% of the taxa were strongly associated with hemlock. In addition, invertebrate taxa were more evenly distributed (i.e., higher Simpson's evenness values) in hemlock-drained streams. In contrast, the number of rare species and total densities were significantly lower in streams draining hemlock, suggesting that diversity differences observed between forest types were not related to stochastic factors associated with sampling and that streams draining mixed hardwood forests may be more productive. Analysis of stream habitat data indicated that streams draining hemlock forests had more stable thermal and hydrologic regimes. Our findings suggest that hemlock decline may result in long-term changes in headwater ecosystems leading to reductions in both within-stream (i.e., alpha) and park-wide (i.e., gamma) benthic community diversity.

  17. Nutrient availability for phytoplankton production along a headwater-to-mainstream reservoir gradient

    SciTech Connect

    Elser, J.J.; Kimmel, B.L.

    1984-12-01

    The occurrence of phytoplankton nutrient deficiency in a headwater-to-mainstream series of three reservoirs was examined using analyses of dissolved nutrients, nutrient enrichment experiments and an alkaline phosphatase bioassay. Size-fractionation of APA showed it to be primarily (75%) associated with 1.0-..mu..m particles, and enzyme suppression experiments demonstrated that, while APA was suppressed by phosphorus enrichment, a residual amount was insensitive to elevated PO/sub 4/-P. Nutrient analyses and nutrient enrichment experiments indicated potential phosphorus limitation of phytoplankton growth in the series, but comparisons of nutrient analyses, enrichment experiments, and APA patterns emphasized the importance of multiple limiting factors in situ. Specific APA increased moving downlake within individual reservoirs in a manner consistent with the river-lake hybrid analogy. A pattern of decreasing phosphorus deficiency moving downstream in the series agreed with predictions based on possible effects of hypolimnetic releases on downstream nutrient availability, but other factors may have contributed to this pattern. 90 references, 16 figures, 8 tables.

  18. Riparian communities associated with Pacific Northwest headwater streams: assemblages, processes, and uniqueness

    USGS Publications Warehouse

    Richardson, J.S.; Naiman, R.J.; Swanson, F.J.; Hibbs, D.E.

    2005-01-01

    Riparian areas of large streams provide important habitat to many species and control many instream processes a?? but is the same true for the margins of small streams? This review considers riparian areas alongside small streams in forested, mountainous areas of the Pacific Northwest and asks if there are fundamental ecological differences from larger streams and from other regions and if there are consequences for management from any differences. In the moist forests along many small streams of the Pacific Northwest, the contrast between the streamside and upslope forest is not as strong as that found in drier regions. Small streams typically lack floodplains, and the riparian area is often constrained by the hillslope. Nevertheless, riparian-associated organisms, some unique to headwater areas, are found along small streams. Disturbance of hillslopes and stream channels and microclimatic effects of streams on the riparian area provide great heterogeneity in processes and diversity of habitats. The tight coupling of the terrestrial riparian area with the aquatic system results from the closed canopy and high edge-to-area ratio for small streams. Riparian areas of the temperate, conifer dominated forests of the Pacific Northwest provide a unique environment. Forest management guidelines for small streams vary widely, and there has been little evaluation of the local or downstream consequences of forest practices along small streams.

  19. Before and after integrated catchment management in a headwater catchment: changes in water quality.

    PubMed

    Hughes, Andrew O; Quinn, John M

    2014-12-01

    Few studies have comprehensively measured the effect on water quality of catchment rehabilitation measures in comparison with baseline conditions. Here we have analyzed water clarity and nutrient concentrations and loads for a 13-year period in a headwater catchment within the western Waikato region, New Zealand. For the first 6 years, the entire catchment was used for hill-country cattle and sheep grazing. An integrated catchment management plan was implemented whereby cattle were excluded from riparian areas, the most degraded land was planted in Pinus radiata, channel banks were planted with poplar trees and the beef cattle enterprise was modified. The removal of cattle from riparian areas without additional riparian planting had a positive and rapid effect on stream water clarity. In contrast, the water clarity decreased in those sub-catchments where livestock was excluded but riparian areas were planted with trees and shrubs. We attribute the decrease in water clarity to a reduction in groundcover vegetation that armors stream banks against preparatory erosion processes. Increases in concentrations of forms of P and N were recorded. These increases were attributed to: (i) the reduction of instream nutrient uptake by macrophytes and periphyton due to increased riparian shading; (ii) uncontrolled growth of a nitrogen fixing weed (gorse) in some parts of the catchment, and (iii) the reduction in the nutrient attenuation capacity of seepage wetlands due to the decrease in their areal coverage in response to afforestation. Our findings highlight the complex nature of the water quality response to catchment rehabilitation measures.

  20. Before and After Integrated Catchment Management in a Headwater Catchment: Changes in Water Quality

    NASA Astrophysics Data System (ADS)

    Hughes, Andrew O.; Quinn, John M.

    2014-12-01

    Few studies have comprehensively measured the effect on water quality of catchment rehabilitation measures in comparison with baseline conditions. Here we have analyzed water clarity and nutrient concentrations and loads for a 13-year period in a headwater catchment within the western Waikato region, New Zealand. For the first 6 years, the entire catchment was used for hill-country cattle and sheep grazing. An integrated catchment management plan was implemented whereby cattle were excluded from riparian areas, the most degraded land was planted in Pinus radiata, channel banks were planted with poplar trees and the beef cattle enterprise was modified. The removal of cattle from riparian areas without additional riparian planting had a positive and rapid effect on stream water clarity. In contrast, the water clarity decreased in those sub-catchments where livestock was excluded but riparian areas were planted with trees and shrubs. We attribute the decrease in water clarity to a reduction in groundcover vegetation that armors stream banks against preparatory erosion processes. Increases in concentrations of forms of P and N were recorded. These increases were attributed to: (i) the reduction of instream nutrient uptake by macrophytes and periphyton due to increased riparian shading; (ii) uncontrolled growth of a nitrogen fixing weed (gorse) in some parts of the catchment, and (iii) the reduction in the nutrient attenuation capacity of seepage wetlands due to the decrease in their areal coverage in response to afforestation. Our findings highlight the complex nature of the water quality response to catchment rehabilitation measures.

  1. A field and modeling study of nonlinear storage-discharge dynamics for an Alpine headwater catchment

    NASA Astrophysics Data System (ADS)

    Camporese, Matteo; Penna, Daniele; Borga, Marco; Paniconi, Claudio

    2014-02-01

    A process-based coupled model of surface-subsurface flow is applied to the simulation of nonlinear hydrological dynamics for an experimental mountain headwater catchment in northeastern Italy. The comparison between measured and simulated responses, both distributed (water table and soil moisture) and integrated (streamflow at the outlet), shows that the model satisfactorily reproduces various nonlinear processes, in particular threshold behavior and hysteresis in the catchment storage-discharge relationship. We typically observe a clockwise loop in this relationship, i.e., streamflow response is faster than groundwater and soil moisture response, due to larger time scales for subsurface processes and to soil moisture persistence and redistribution. The model is based on a standard Richards equation representation of integrated saturated-unsaturated-runoff dynamics and needs no ad hoc parameterization (e.g., for macropores, pipe flow, or retention curve hysteresis) to capture observed hysteretic relationships between storage and discharge. Additional numerical experiments are carried out to investigate how heterogeneity (bedrock permeability and the distinction between riparian and hillslope areas) and aquifer thickness and topography affect this nonlinear dynamics. The results show that catchment topography and soil depth exert the main control on the hysteresis and threshold patterns. This is evident from a spatial analysis of streamflow and water table response times to storm events, where the threshold points correspond to changes in terrain slope. These findings are confirmed by a further set of analyses carried out on an idealized v-shaped catchment.

  2. Fate and transport of polycyclic aromatic hydrocarbons in upland irish headwater lake catchments.

    PubMed

    Scott, Heidi E M; Aherne, Julian; Metcalfe, Chris D

    2012-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are a concern due to their carcinogenicity and propensity for transboundary atmospheric transport. Ireland is located on the western periphery of Europe and assumed to receive clean Atlantic air. As such, it has been used as an atmospheric reference for comparison to other regions. Nonetheless, few studies have evaluated concentrations of PAHs within the Irish environment. In the current study, PAHs were measured at five upland (500-800 masl) headwater lake catchments in coastal regions around Ireland, remote from industrial point source emissions. Semipermeable membrane devices were deployed in lakes for a 6-month period in July 2009, and topsoils were sampled from each catchment during October 2010. The concentrations of PAHs were low at most study sites with respect to other temperate regions. Homologue groups partitioned between lake and soil compartments based on their molecular weight were: "lighter" substances, such as Phenanthrene and Fluorene, were found in higher proportions in lakes, whereas "heavier" compounds, such as Chrysene and Benz[a]anthracene, were more prominent in soils. Concentrations of PAHs were highest at the east coast sites, potentially due to contributions from historical transboundary and regional combustion sources.

  3. Logging in western Oregon: responses of headwater habitats and stream amphibians

    USGS Publications Warehouse

    Corn, Paul Stephen; Bury, R. Bruce

    1989-01-01

    We compared occurrence and abundance of four species of aquatic amphibians in 23 streams flowing through uncut forests to 20 streams flowing through forests logged between 14 and 40 years prior to the study. Species richness was highest in streams in uncut forests. Eleven streams in uncut forests contained all four species, and only two of these streams had fewer than three species present. Eleven streams in logged stands had one or no species present, and only one contained all four species. Density and biomass of all four species were significantly greater (2–7 X) in streams in uncut forests. Physical comparisons between types of streams were similar, except that streams in logged stands had generally smaller substrata, resulting from increased sedimentation. Densities of Pacific giant salamanders (Dicamptodon ensatus) and Olympic salamanders (Rhyacotriton olymoicus) were positively correlated with stream gradient in logged stands, but not in uncut forests, suggesting that the disruptive effects of increased sedimentation are greatest in low-gradient streams. Tailed frogs (Ascaphus truei) and Dunn's salamanders (Plethodon dunni) occurred more often in streams in logged stands when uncut timber was present upstream, but neither density nor biomass of any species were related to either presence of uncut timber upstream or years since logging. Logging upstream from uncut forests also had no effect on the presence, density or biomass of any species. Tailed frogs and Olympic salamanders may be extirpated from headwaters traversing clearcuts; these streams should be afforded some protection in plans for managed forests.

  4. Fate and Transport of Polycyclic Aromatic Hydrocarbons in Upland Irish Headwater Lake Catchments

    PubMed Central

    Scott, Heidi E. M.; Aherne, Julian; Metcalfe, Chris D.

    2012-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are a concern due to their carcinogenicity and propensity for transboundary atmospheric transport. Ireland is located on the western periphery of Europe and assumed to receive clean Atlantic air. As such, it has been used as an atmospheric reference for comparison to other regions. Nonetheless, few studies have evaluated concentrations of PAHs within the Irish environment. In the current study, PAHs were measured at five upland (500–800 masl) headwater lake catchments in coastal regions around Ireland, remote from industrial point source emissions. Semipermeable membrane devices were deployed in lakes for a 6-month period in July 2009, and topsoils were sampled from each catchment during October 2010. The concentrations of PAHs were low at most study sites with respect to other temperate regions. Homologue groups partitioned between lake and soil compartments based on their molecular weight were: “lighter” substances, such as Phenanthrene and Fluorene, were found in higher proportions in lakes, whereas “heavier” compounds, such as Chrysene and Benz[a]anthracene, were more prominent in soils. Concentrations of PAHs were highest at the east coast sites, potentially due to contributions from historical transboundary and regional combustion sources. PMID:23346024

  5. Spatial and Temporal influence of Redondo Peak headwaters in the East Fork Jemez River using Principal Component Analysis approach, Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Sanchez, Rodrigo; Meixner, Thomas

    2015-04-01

    The Valles Caldera is a volcanic collapse feature located in the Jemez Mountains in northern New Mexico, southwestern United States. This region is characterized by a bimodal precipitation pattern, i.e. spring snowmelt and summer monsoon rains. Two main streams flow through the Valles Caldera: San Antonio and East Fork Jemez. The junction of these two rivers form the Jemez River which is an important contributor to the Rio Grande that supplies water to cities located in southwestern U.S. Redondo Peak is located in the center of the Valles Caldera that has several springs that drain around all sides of the peak with different hydrologic responses. The main catchments (headwaters) identified in Redondo Peak are: La Jara, Upper Jaramillo, History Grove and Upper Redondo. The main questions that are going to be answered in this research are: Do these head waters affect the chemistry in East Fork Jemez river? and if so, how does this influence vary in space and time? A Principal Component Analysis (PCA) was performed using analyzed water samples for water isotopes and major anions and cations. These samples were collected from the flumes located at each catchment in Redondo Peak, and at different locations along the East Fork Jemez. Samples from the most consistent analytes from 2011 to 2013 were used in this present work. A first PCA was performed to assess how different the La Jara catchment is from Upper Redondo, Upper Jaramillo and History Grove based on the geochemistry of each basin. Prior the analysis the data needs to be normalized in order to avoid biasing towards extreme values. Since La Jara is the reference site for this analysis, its mean and standard deviation were used to normalized the data set of the other catchments. In order to simplify this analysis the two first principal components for each catchment were used to do the projections regardless how much of the variability can be explained. However future analyses are going to be performed with those

  6. BASINS Technical Notes

    EPA Pesticide Factsheets

    EPA has developed several technical notes that provide in depth information on a specific function in BASINS. Technical notes can be used to answer questions users may have, or to provide additional information on the application of features in BASINS.

  7. BASINS Tutorials and Training

    EPA Pesticide Factsheets

    A series of lectures and exercises on how to use BASINS for water quality modeling and watershed assessment. The lectures follow sequentially. Companion exercises are provided for users to practice different BASINS water quality modeling techniques.

  8. Riparian zone flowpath dynamics during snowmelt in a small headwater catchment

    USGS Publications Warehouse

    McGlynn, B.L.; McDonnell, Jeffery J.; Shanley, J.B.; Kendall, C.

    1999-01-01

    The hydrology of the near-stream riparian zone in upland humid catchments is poorly understood. We examined the spatial and temporal aspects of riparian flowpaths during snowmelt in a headwater catchment within the Sleepers River catchment in northern Vermont. A transect of 15 piezometers was sampled for Ca, Si, DOC, other major cations, and ??18O. Daily piezometric head values reflected variations in the stream hydrograph induced by melt and rainfall. The riparian zone exhibited strong upward discharge gradients. An impeding layer was identified between the till and surficial organic soil. Water solute concentrations increased toward the stream throughout the melt. Ca concentrations increased with depth and DOC concentrations decreased with depth. The concentrations of Ca in all piezometers were lower during active snowmelt than during post-melt low flow. Ca data suggest snowmelt infiltration to depth; however, only upslope piezometers exhibited snowmelt infiltration and consequent low ??18O values, while ??18O values varied less than 0.5% in the deep riparian piezometers throughout the study period. Ca and ??18O values in upslope piezometers during low streamflow were comparable to Ca and ??18O in riparian piezometers during high streamflow. The upland water Ca and ??18O may explain the deep riparian Ca dilution and consistent ??18O composition. The temporal pattern in Ca and ??18O indicate that upland water moves to the stream via a lateral displacement mechanism that is enhanced by the presence of distinct soil/textural layers. Snowmelt thus initiates the flux of pre-melt, low Ca upland water to depth in the riparian zone, but itself does not appear at depth in the riparian zone during spring melt. This is despite the coincident response of upland groundwater and stream discharge.The hydrology of the near-stream riparian zone in upland humid catchments is poorly understood. We examined the spatial and temporal aspects of riparian flowpaths during snowmelt in a

  9. The Imbalance between Nature and Management: Jurisdictional Evaluation of Headwaters in a Mountain Watershed (Invited)

    NASA Astrophysics Data System (ADS)

    Caruso, B. S.

    2013-12-01

    In mountain ecoregions of the semi-arid western U.S., there is an imbalance between science and policy for jurisdictional determinations of aquatic resource as ';waters of the US' that can be protected under Clean Water Act Section 404 (permitting discharge of dredged and fill materials into wetlands and other waters). This leads to continued degradation of surface waters due to the imbalance of key biophysical and societal/regulatory components; the imbalance of water across these drier landscapes, and the imbalance between the critical ecological services provided by these headwater areas and the increasing impacts from urbanization and energy development in previously undeveloped areas. This study analysed headwater streams in a mountain watershed in southwestern Colorado and developed a classification scheme and hydrological connectivity index to demonstrate jurisdictional evaluation at a watershed scale. The National Hydrography Dataset and USGS program StreamStats were used with field observations to classify flow duration and stream order used for Level 1 and 2 classification. Kruskall Wallis tests and discriminant analysis were used to evaluate differences among Level 1 and 2 classes. Hierarchical cluster analysis was used to develop Level 3 classes based on stream length, distance to the nearest downstream traditional navigable water (TNW), and the ratio of mean annual flow from the source stream to the TNW. Three primary metrics were used for HCI development: Avg Q/AQ, or the average streamflow metric as a proportion of the metric for the TNW, distance from the stream to the TNW, and slope to the TNW. Additional metrics were also analyzed including stream length, elevation, channel slope and type, and riparian zone types. Perennial waters constitute over a third of all streams (the highest order of which is 4th order), 64% of all reaches are intermittent or ephemeral, and almost half are ephemeral 1st order (E1). The perennial and intermittent streams are

  10. Spatial patterns of soil nitrification and nitrate export from forested headwaters in the northeastern United States

    NASA Astrophysics Data System (ADS)

    Ross, Donald S.; Shanley, James B.; Campbell, John L.; Lawrence, Gregory B.; Bailey, Scott W.; Likens, Gene E.; Wemple, Beverley C.; Fredriksen, Guinevere; Jamison, Austin E.

    2012-03-01

    Nitrogen export from small forested watersheds is known to be affected by N deposition but with high regional variability. We studied 10 headwater catchments in the northeastern United States across a gradient of N deposition (5.4 - 9.4 kg ha-1 yr-1) to determine if soil nitrification rates could explain differences in stream water NO3- export. Average annual export of two years (October 2002 through September 2004) varied from 0.1 kg NO3--N ha-1 yr-1 at Cone Pond watershed in New Hampshire to 5.1 kg ha-1 yr-1 at Buck Creek South in the western Adirondack Mountains of New York. Potential net nitrification rates and relative nitrification (fraction of inorganic N as NO3-) were measured in Oa or A soil horizons at 21-130 sampling points throughout each watershed. Stream NO3- export was positively related to nitrification rates (r2 = 0.34, p = 0.04) and the relative nitrification (r2 = 0.37, p = 0.04). These relationships were much improved by restricting consideration to the 6 watersheds with a higher number of rate measurements (59-130) taken in transects parallel to the streams (r2 of 0.84 and 0.70 for the nitrification rate and relative nitrification, respectively). Potential nitrification rates were also a better predictor of NO3- export when data were limited to either the 6 sampling points closest to the watershed outlet (r2 = 0.75) or sampling points <250 m from the watershed outlet (r2 = 0.68). The basal area of conifer species at the sampling plots was negatively related to NO3-export. These spatial relationships found here suggest a strong influence of near-stream and near-watershed-outlet soils on measured stream NO3- export.

  11. Stream Ammonium Uptake Across Scales in Headwater Catchments of a Tropical Rainforest, Luquillo Mountains, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Brereton, R. L.; McDowell, W. H.; Wymore, A.

    2015-12-01

    Many tropical forest streams export high amounts of nitrogen relative to streams draining undisturbed watersheds of other biomes. With their low DOC concentrations and high rates of respiration, headwater streams in the Luquillo Mountains have been previously characterized as energy-limited, suggesting that NH4+ uptake is dominated not by N demand but by energy demand. In the Rio Icacos watershed, high concentrations of NH4+ (>1 mg N/L) are found in groundwater adjacent to the streams, making high inputs of NH4+ to the stream channel via groundwater seepage likely. Stream nutrient spiraling metrics can be used to quantify uptake and retention rates of specific nutrients, and can be measured by solute additions. Tracer Additions for Spiraling Curve Characterization (TASCC) is a recently developed method (Covino et al. 2010) for quantifying nutrient uptake with a single slug addition of nutrient and conservative tracer. Here we present NH4+ uptake metrics from TASCC additions in three Luquillo streams of different sizes, ranging from 2nd to 4th order: the Rio Icacos, a larger, 3rd order tributary and a smaller 2nd order tributary. Background NH4+ concentrations vary by up to an order of magnitude, with highest concentrations (27 μg N/L) found in the smaller tributary. Background DOC concentrations are uniformly low and show no difference between the three streams (500-600 μg C/L). The smaller tributary has the shortest uptake length (155 m) and highest uptake velocity (2.9 mm/min) of the three streams. Unexpectedly, the Rio Icacos has a higher uptake velocity (1.7 mm/min) than the larger tributary (1.0 mm/min), despite having an uptake length more than double (1400 m) that of the larger tributary (596 m). Overall, NH4+ uptake is substantial in all three streams and varies with background concentrations, not stream size.

  12. Chemical regulation of alpine headwater streams during a storm event (Bogong High Plains, Victoria, Australia)

    NASA Astrophysics Data System (ADS)

    Karis, Terry; Silvester, Ewen; Rees, Gavin

    2016-11-01

    The headwater streams originating in the Australian Alps are the highest water yielding landscape in South-Eastern Australia and are projected to be impacted by climate change through longer dry periods and more episodic rainfall. In this work we studied the major ion and DOC responses of three alpine peatlands (and the broader catchment containing these systems) to a high intensity (summer) storm event. Despite the high volume of rainfall, major ions in stream waters remained strongly chemostatic throughout the event. This was particularly the case for Ca2+ and Mg2+, as well as the alkalinity by association, and suggests that chemical regulation of these particular cations occurs through rapid equilibration processes. DOC concentrations increased during the storm pulse, leading to a shift in alkalinity partitioning from bicarbonate to organic anions and a decrease in pH, mediated by the CO2 saturation levels in the stream water. Our results suggest that alkalinity generation (Ca2+ and Mg2+ acquisition) and partitioning (DOC export) are decoupled processes that may respond differently to repeat storm events depending on the capacity of these systems to provide these constituents. Under extreme case scenarios depletion of DOC (at constant alkalinity) would lead to a smaller pH dip during a storm pulse, while depletion of alkalinity would lead to a larger pH dip, with buffering controlled by free acid. We have not identified the mechanism for the chemostasis of Ca2+ and Mg2+ (and therefore alkalinity) in this work, but this will be critical to understanding the capacity of these peatlands to respond to repeat and more intense storm events.

  13. Instream Wood Loads and Channel Complexity in Headwater Streams Under Alternative Stable States

    NASA Astrophysics Data System (ADS)

    Livers, B.; Wohl, E.

    2014-12-01

    Channel morphology and irregularities in stream boundaries can create zones of flow separation, where lower velocities trap fine sediment and organic matter and increase opportunities for nutrient processing and biological uptake. This effect is most pronounced with channel-spanning structures such as logjams. Humans have changed the spatial and temporal characteristics of wood distribution in streams, with lasting effects on instream wood recruitment, wood loads, logjam distribution, and hydraulic roughness. Previous studies in the Colorado Front Range show that contemporary headwater streams flowing through old-growth, unmanaged forests have more wood than streams flowing through younger-growth, managed forests, but do not evaluate the effects of wood on channel complexity. 'Managed' versus 'unmanaged' refers to whether forests were or are currently exposed to human alteration. Although some alteration has long since ceased, reduced wood loads in managed streams persist. Our primary objective was to quantify differences in logjams, wood volumes, stream complexity, and organic carbon storage on streams with different management and disturbance histories in order to examine legacy effects across a gradient of stream management. Data were collected during the summers of 2013 and 2014 in the Southern Rocky Mountains. The 25 stream reaches studied are 2nd to 3rd order, subalpine streams that are categorized into: old-growth unmanaged forests; younger, naturally disturbed unmanaged forests; and younger managed forests. We assessed instream and floodplain wood loads and logjams and evaluated the role that large wood plays in local channel complexity, pool volume, and storage of organic carbon. Preliminary results show that greatest wood and carbon storage in sediments, as well as channel complexity, occurs in streams in old-growth, unmanaged forests and the least wood and carbon storage and channel complexity occurs in younger-growth, managed forests.

  14. Upland disturbance affects headwater stream nutrients and suspended sediments during baseflow and stormflow

    USGS Publications Warehouse

    Houser, J.N.; Mulholland, P.J.; Maloney, K.O.

    2006-01-01

    Because catchment characteristics determine sediment and nutrient inputs to streams, upland disturbance can affect stream chemistry. Catchments at the Fort Benning Military Installation (near Columbus, Georgia) experience a range of upland disturbance intensities due to spatial variability in the intensity of military training. We used this disturbance gradient to investigate the effects of upland soil and vegetation disturbance on stream chemistry. During baseflow, mean total suspended sediment (TSS) concentration and mean inorganic suspended sediment (ISS) concentration increased with catchment disturbance intensity (TSS: R2 = 0.7, p = 0.005, range = 4.0-10.1 mg L-1; ISS: R2 = 0.71, p = 0.004, range = 2.04-7.3 mg L-1); dissolved organic carbon (DOC) concentration (R2 = 0.79, p = 0.001, range = 1.5-4.1 mg L-1) and soluble reactive phosphorus (SRP) concentration (R2 = 0.75, p = 0.008, range = 1.9-6.2 ??g L-1) decreased with increasing disturbance intensity; and ammonia (NH 4+), nitrate (NO3-), and dissolved inorganic nitrogen (DIN) concentrations were unrelated to disturbance intensity. The increase in TSS and ISS during storms was positively correlated with disturbance (R2 = 0.78 and 0.78, p = 0.01 and 0.01, respectively); mean maximum change in SRP during storms increased with disturbance (r = 0.7, p = 0.04); and mean maximum change in NO3- during storms was marginally correlated with disturbance (r = 0.58, p = 0.06). Soil characteristics were significant predictors of baseflow DOC, SRP, and Ca 2+, but were not correlated with suspended sediment fractions, any nitrogen species, or pH. Despite the largely intact riparian zones of these headwater streams, upland soil and vegetation disturbances had clear effects on stream chemistry during baseflow and stormflow conditions. ?? ASA, CSSA, SSSA.

  15. Downstream Warming and Headwater Acidity May Diminish Coldwater Habitat in Southern Appalachian Mountain Streams

    PubMed Central

    Jackson, W. A; Sams, C.

    2015-01-01

    Stream-dwelling species in the U.S. southern Appalachian Mountains region are particularly vulnerable to climate change and acidification. The objectives of this study were to quantify the spatial extent of contemporary suitable habitat for acid- and thermally sensitive aquatic species and to forecast future habitat loss resulting from expected temperature increases on national forest lands in the southern Appalachian Mountain region. The goal of this study was to help watershed managers identify and assess stream reaches that are potentially vulnerable to warming, acidification, or both. To our knowledge, these results represent the first regional assessment of aquatic habitat suitability with respect to the combined effects of stream water temperature and acid-base status in the United States. Statistical models were developed to predict July mean daily maximum water temperatures and air-water temperature relations to determine potential changes in future stream water temperatures. The length of stream considered suitable habitat for acid- and thermally sensitive species, based on temperature and acid neutralizing capacity thresholds of 20°C and 50 μeq/L, was variable throughout the national forests considered. Stream length displaying temperature above 20°C was generally more than five times greater than the length predicted to have acid neutralizing capacity below 50 μeq/L. It was uncommon for these two stressors to occur within the same stream segment. Results suggested that species’ distributional shifts to colder, higher elevation habitats under a warming climate can be constrained by acidification of headwater streams. The approach used in this study can be applied to evaluate climate change impacts to stream water resources in other regions. PMID:26247361

  16. Blanket peatland restoration leads to reduced storm runoff from headwater systems

    NASA Astrophysics Data System (ADS)

    Shuttleworth, Emma; Allott, Tim; Evans, Martin; Pilkington, Mike

    2016-04-01

    This paper presents data on the impact of largescale peatland restoration on catchment runoff from peatlands in northern England. The blanket peatlands of the Pennine hills are important sources of water supply and form the headwaters of major river systems. These peatlands are severely eroded with extensive gullying and bare peat resulting from the impacts of industrial pollution, overgrazing, wildfire and climatic change over the last millennium. In the last decade there has been a major programme of peatland restoration through re-vegetation and blocking of drainage lines in these systems. The Making Space for Water project has collected hydrological data from five micro-catchments(two restoration treatments, a bare peat control, a vegetated control and a previously restored site) over a four year period. This has allowed for both Before-After-Control-Intervention and Space for Time analysis of the impact of restoration on downstream runoff. Catchments became wetter following re-vegetation, water tables rose by 35 mm and overland flow production increased by 18%. Storm-flow lag times in restored catchments increased by up to 267 %, while peak storm discharge decreased by up to 37%. There were no statistically significant changes in percentage runoff, indicating limited changes to within-storm catchment storage. Natural flood management solutions are typically focussed around one of two main mechanisms, either enhanced storage of water in catchments or measures which slow transmission of water to channels and within channels. Upland peatlands are often mischaracterised as sponges and assumed to mitigate downstream runoff through additional storage. The results of this study suggest that whilst restoration of upland peatlands can lead to significant reductions in peak discharge, and has potential to contribute to natural flood risk management, the mechanism is an increase in catchment roughness and an associated decrease in flow velocities.

  17. Spatial patterns of soil nitrification and nitrate export from forested headwaters in the northeastern United States

    USGS Publications Warehouse

    Ross, D.S.; Shanley, J.B.; Campbell, J.L.; Lawrence, G.B.; Bailey, S.W.; Likens, G.E.; Wemple, B.C.; Fredriksen, G.; Jamison, A.E.

    2012-01-01

    Nitrogen export from small forested watersheds is known to be affected by N deposition but with high regional variability. We studied 10 headwater catchments in the northeastern United States across a gradient of N deposition (5.4 - 9.4 kg ha -1 yr -1) to determine if soil nitrification rates could explain differences in stream water NO 3 - export. Average annual export of two years (October 2002 through September 2004) varied from 0.1 kg NO 3 --N ha -1 yr -1 at Cone Pond watershed in New Hampshire to 5.1 kg ha -1 yr -1 at Buck Creek South in the western Adirondack Mountains of New York. Potential net nitrification rates and relative nitrification (fraction of inorganic N as NO 3 -) were measured in Oa or A soil horizons at 21-130 sampling points throughout each watershed. Stream NO 3 - export was positively related to nitrification rates (r 2 = 0.34, p = 0.04) and the relative nitrification (r 2 = 0.37, p = 0.04). These relationships were much improved by restricting consideration to the 6 watersheds with a higher number of rate measurements (59-130) taken in transects parallel to the streams (r 2 of 0.84 and 0.70 for the nitrification rate and relative nitrification, respectively). Potential nitrification rates were also a better predictor of NO 3 - export when data were limited to either the 6 sampling points closest to the watershed outlet (r 2 = 0.75) or sampling points <250 m from the watershed outlet (r 2 = 0.68). The basal area of conifer species at the sampling plots was negatively related to NO 3 - export. These spatial relationships found here suggest a strong influence of near-stream and near-watershed-outlet soils on measured stream NO 3 - export. Copyright 2012 by the American Geophysical Union.

  18. Hydrologic Connectivity in Headwater Catchments Underlain by Continuous Permafrost: Hydrological, Thermal and Biogeochemical Patterns

    NASA Astrophysics Data System (ADS)

    Godsey, S.; Rushlow, C. R.; Harms, T.

    2014-12-01

    Hydrologic connectivity within headwater fluvial networks depends largely on subsurface patterns of moisture. Dynamic subsurface properties that control those patterns can vary widely and are poorly constrained in many systems. However, subsurface conditions change seasonally in a predictable way in catchments underlain by permafrost due to increasing thaw throughout the summer season, and those changes can be systematically measured. Zero-order linear flow features known as water tracks are found in upland permafrost hillslopes and occupy up to 35% of the landscape. Water tracks often connect to downstream fluvial systems via subsurface pathways, but those connections are poorly understood. We present data from six water tracks underlain by permafrost in northern Alaska. We improve our understanding of water tracks and their connections to downstream fluvial systems in two ways. First, we compare the fraction of snow and rain comprising flows in water tracks and the downstream systems to which they connect, and we discuss the resulting constraints on biogeochemical fluxes in these systems. Second, we examine the subsurface controls on water track connectivity patterns by characterizing the water tracks' thermal signatures. We demonstrate that a shallow unfrozen layer permits subsurface flow to continue below a surface frozen layer for up to 6 months after air temperatures drop below freezing, enhancing fall and winter water track downstream connectivity. Because winter air temperatures are projected to increase and become more variable, we examine the role of freeze-thaw events on hydrologic connectivity: some water tracks are less responsive to rapid air temperature changes than surrounding hillslopes. At these sites, soils inside the water tracks remain frozen and impermeable for ~10 more days each year and cycle through fewer freeze-thaw cycles than the same soils outside water tracks. Some shallow soils outside some water tracks freeze and thaw up to 3-fold

  19. Upland disturbance affects headwater stream nutrients and suspended sediments during baseflow and stormflow

    SciTech Connect

    Houser, Jeffrey N

    2006-01-01

    Because catchment characteristics determine sediment and nutrient inputs to streams, upland disturbance can affect stream chemistry. Catchments at the Fort Benning Military Installation (near Columbus, Georgia) experience a range of upland disturbance intensities due to spatial variability in the intensity of military training. We used this disturbance gradient to investigate the effects of upland soil and vegetation disturbance on stream chemistry. During baseflow, mean total suspended sediment (TSS) concentration and mean inorganic suspended sediment (ISS) concentration increased with catchment disturbance intensity (TSS: R 2 = 0.7, p = 0.005, range = 4.0-10.1 mg L-1; ISS: R 2 = 0.71, p = 0.004, range = 2.04-7.3 mg L-1); dissolved organic carbon (DOC) concentration (R 2 = 0.79, p = 0.001, range = 1.5-4.1 mg L-1) and soluble reactive phosphorus (SRP) concentration (R 2 = 0.75, p = 0.008, range = 1.9-6.2 {micro}g L-1) decreased with increasing disturbance intensity; and ammonia (NH4 +), nitrate (NO3 -), and dissolved inorganic nitrogen (DIN) concentrations were unrelated to disturbance intensity. The increase in TSS and ISS during storms was positively correlated with disturbance (R 2 = 0.78 and 0.78, p = 0.01 and 0.01, respectively); mean maximum change in SRP during storms increased with disturbance (r = 0.7, p = 0.04); and mean maximum change in NO3 - during storms was marginally correlated with disturbance (r = 0.58, p = 0.06). Soil characteristics were significant predictors of baseflow DOC, SRP, and Ca2+, but were not correlated with suspended sediment fractions, any nitrogen species, or pH. Despite the largely intact riparian zones of these headwater streams, upland soil and vegetation disturbances had clear effects on stream chemistry during baseflow and stormflow conditions.

  20. Increasing fish taxonomic and functional richness affects ecosystem properties of small headwater prairie streams

    SciTech Connect

    Martin, Erika C.; Gido, Keith B.; Bello, Nora; Dodds, Walter K.; Veach, Allison

    2016-04-06

    Stream fish can regulate their environment through direct and indirect pathways, and the relative influence of communities with different taxonomic and functional richness on ecosystem properties likely depends on habitat structure. Given this complexity, it is not surprising that observational studies of how stream fish communities influence ecosystems have shown mixed results. In this study, we evaluated the effect of an observed gradient of taxonomic (zero, one, two or three species) and functional (zero, one or two groups) richness of fishes on several key ecosystem properties in experimental stream mesocosms. Our study simulated small (less than two metres wide) headwater prairie streams with a succession of three pool-riffle structures (upstream, middle and downstream) per mesocosm. Additionally, ecosystem responses included chlorophyll a from floating algal mats and benthic algae, benthic organic matter, macroinvertebrates (all as mass per unit area), algal filament length and stream metabolism (photosynthesis and respiration rate). Ecosystem responses were analysed individually using general linear mixed models. Significant treatment (taxonomic and functional richness) by habitat (pools and riffles) interactions were found for all but one ecosystem response variable. After accounting for location (upstream, middle and downstream) effects, the presence of one or two grazers resulted in shorter mean algal filament lengths in pools compared to no-fish controls. These observations suggest grazers can maintain short algal filaments in pools, which may inhibit long filaments from reaching the surface. Accordingly, floating algal mats decreased in mid- and downstream locations in grazer treatment relative to no-fish controls. At the scale of the entire reach, gross primary productivity and respiration were greater in treatments with two grazer species compared to mixed grazer/insectivore or control treatments. Lastly, the distribution of stream resources across

  1. DOC Dynamics in Small Headwater Streams: the Role of Hydrology, Climate, and Land Management

    NASA Astrophysics Data System (ADS)

    Lajtha, K.; Lee, B. S.; Jones, J. A.

    2015-12-01

    Dissolved organic carbon (DOC) is a critical component of the carbon (C) cycle of both terrestrial and aquatic systems. For small headwater allochthonous streams, terrestrial C delivery fuels the metabolism of receiving waters and significantly influences biotic diversity and function. While nutrient fluxes in streams have long been used as indicators of terrestrial ecosystem processes, less attention has been given to terrestrial controls on DOC export. We used the long-term stream chemistry records from the H.J. Andrews Forest LTER to examine forest management, climatic, and hydrologic controls on both seasonal and annual DOC fluxes. Within a watershed, annual DOC flux was highly related to annual discharge (Q), although considerable variability in higher discharge years suggested a role for indices of storminess, especially early in the water year. Among watersheds, younger, previously harvested watersheds generally had significantly lower DOC fluxes for a given Q than old-growth watersheds, even 4+ decades after harvest. The exception to this pattern was a harvested watershed that had significant downed wood retained on site, and had densities of coarse woody debris (CWD) close to that of the old-growth watersheds even though live tree biomass was similar to the other harvested watersheds. Other climatic factors did not appear to have significant roles in predicting either seasonal or annual fluxes of DOC. This is in sharp contrast to fluxes of nitrate at our site, which appears to be related most significantly to the presence of alder within the watershed. Taken together, our data suggest a persistent and cascading role for CWD in old-growth forest ecosystems.

  2. Biotic drivers of anastomosing channel pattern in headwater streams of the Colorado Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Wohl, E. E.

    2010-12-01

    Most of the headwater rivers in the Colorado Rocky Mountains, USA occur as single channels in steep, narrow valleys. Where variations in bedrock erodibility create segments of wider, lower gradient valleys, however, anastomosing channels can occur if one of two biotic drivers is present. Where a disturbance such as a forest fire or windstorm allows pioneer woody species to colonize valley bottoms, beavers can establish colonies. Beavers build dams that enhance overbank flooding and raise the local water table, limiting the return of conifers and promoting aspen-willow (Populus-Salix) forests that provide food for the beavers. Beavers facilitate the formation of multiple channels by digging small canal-like features across the floodplain and by damming the main channel and promoting channel avulsion. In old-growth conifer forests, channel-spanning logjams can enhance overbank flows that facilitate the development of multiple (sub)parallel channels that extend for 50-300 m downstream. Enhanced overbank flows and multiple channels increase the retention of instream wood, creating a self-enhancing feedback of more jams. At least two thresholds must be crossed for anastomosing driven by logjams to develop; a valley morphology threshold and a wood load threshold. Anastomosing channels are present where stream gradient < 4% and the ratio of (channel width/valley-bottom width) < 0.2; only single channels flow through old-growth forests in valley segments that are steeper and narrower. The average wood piece diameter in old-growth anastomosing channel segments > 20 cm, whereas average piece diameter in forests that have not been disturbed in a century is 10-20 cm; channels in these younger forests do not exhibit anastomosing planforms. Wood load in old-growth anastomosing channels averages 200 m3/ha; old-growth and younger forest single channels average < 100 m3/ha.

  3. Hydrochemical analysis of stream water in a tropical, mountainous headwater catchment in northern Thailand

    NASA Astrophysics Data System (ADS)

    Hugenschmidt, C.; Ingwersen, J.; Sangchan, W.; Sukvanachaikul, Y.; Uhlenbrook, S.; Streck, T.

    2010-03-01

    Land use in the vulnerable mountainous parts of the Mae Sa watershed, northern Thailand, has been changed from subsistence agriculture to market-driven production within the past decades. This change is reflected in an increased application of agrochemicals on agricultural areas to secure yields and control pests. Our study site is a steep and fast-responding headwater catchment (77 km2), which transfers agrochemicals that might get lost from soils to waters quickly to the lowlands posing the risk of environmental contamination. This work describes the study, which has been carried out in a subcatchment (7 km2) of the Mae Sa watershed to identify runoff generation processes and contributing flow paths to encircle potential flow paths of pesticides leaching from soil to surface water. We observed three events during the rainy seasons in 2007 and 2008, which were analysed on major ions and EC at high temporal resolution. Based on the samples a two-component hydrograph separation was carried out for three events. For two out of the three events a three-component hydrograph separation was performed to identify the contributions of baseflow, interflow and surface runoff. Baseflow remained the dominant flow fraction, but interflow outshined surface runoff in its amount. Interflow could be observed at the hillslope seeping from the soil in 2007, but not in 2008. We suggest, that interflow highly depends on a constant input of rainfall and requires a certain minimum amount of rainfall per season to be triggered and sustained. Former studies found that pesticides mainly get lost by interflow in this area. Hence, we can point out that pesticide leaching risk is particularly high after a certain amount of rainfall. Critical conditions are therefore mainly present, when the soil layers are close to saturation but not, when these layers are generated or degenerated.

  4. Variability in isotopic composition of base flow in two headwater streams of the southern Appalachians

    NASA Astrophysics Data System (ADS)

    Singh, Nitin K.; Emanuel, Ryan E.; McGlynn, Brian L.

    2016-06-01

    We investigated the influence of hillslope scale topographic characteristics and the relative position of hillslopes along streams (i.e., internal catchment structure) on the isotopic composition of base flow in first-order, forested headwater streams at Coweeta Hydrologic Laboratory. The study focused on two adjacent forested catchments with different topographic characteristics. We used stable isotopes (18O and 2H) of water together with stream gauging and geospatial analysis to evaluate relationships between internal catchment structure and the spatiotemporal variability of base flow δ18O. Base flow δ18O was variable in space and time along streams, and the temporal variability of base flow δ18O declined with increasing drainage area. Base flow became enriched in 18O moving along streams from channel heads to catchment outlets but the frequency of enrichment varied between catchments. The spatiotemporal variability in base flow δ18O was high adjacent to large hillslopes with short flow paths, and it was positively correlated with the relative arrangement of hillslopes within the catchment. These results point to influence of unique arrangement of hillslopes on the patterns of downstream enrichment. Spatial variability in base flow δ18O within the streams was relatively low during dry and wet conditions, but it was higher during the transition period between dry and wet conditions. These results suggest that the strength of topographic control on the isotopic composition of base flow can vary with catchment wetness. This study highlights that topographic control on base flow generation and isotopic composition is important even at fine spatial scales.

  5. Downstream Warming and Headwater Acidity May Diminish Coldwater Habitat in Southern Appalachian Mountain Streams.

    PubMed

    McDonnell, T C; Sloat, M R; Sullivan, T J; Dolloff, C A; Hessburg, P F; Povak, N A; Jackson, W A; Sams, C

    2015-01-01

    Stream-dwelling species in the U.S. southern Appalachian Mountains region are particularly vulnerable to climate change and acidification. The objectives of this study were to quantify the spatial extent of contemporary suitable habitat for acid- and thermally sensitive aquatic species and to forecast future habitat loss resulting from expected temperature increases on national forest lands in the southern Appalachian Mountain region. The goal of this study was to help watershed managers identify and assess stream reaches that are potentially vulnerable to warming, acidification, or both. To our knowledge, these results represent the first regional assessment of aquatic habitat suitability with respect to the combined effects of stream water temperature and acid-base status in the United States. Statistical models were developed to predict July mean daily maximum water temperatures and air-water temperature relations to determine potential changes in future stream water temperatures. The length of stream considered suitable habitat for acid- and thermally sensitive species, based on temperature and acid neutralizing capacity thresholds of 20°C and 50 μeq/L, was variable throughout the national forests considered. Stream length displaying temperature above 20°C was generally more than five times greater than the length predicted to have acid neutralizing capacity below 50 μeq/L. It was uncommon for these two stressors to occur within the same stream segment. Results suggested that species' distributional shifts to colder, higher elevation habitats under a warming climate can be constrained by acidification of headwater streams. The approach used in this study can be applied to evaluate climate change impacts to stream water resources in other regions.

  6. Carbon dynamics in the hyporheic zone of a headwater mountain stream in the Cascade Mountains, Oregon

    NASA Astrophysics Data System (ADS)

    Corson-Rikert, Hayley A.; Wondzell, Steven M.; Haggerty, Roy; Santelmann, Mary V.

    2016-10-01

    We investigated carbon dynamics in the hyporheic zone of a steep, forested, headwater catchment western Oregon, USA. Water samples were collected monthly from the stream and a well network during base flow periods. We examined the potential for mixing of different source waters to explain concentrations of DOC and DIC. We did not find convincing evidence that either inputs of deep groundwater or lateral inputs of shallow soil water influenced carbon dynamics. Rather, carbon dynamics appeared to be controlled by local processes in the hyporheic zone and overlying riparian soils. DOC concentrations were low in stream water (0.04-0.09 mM), and decreased with nominal travel time through the hyporheic zone (0.02-0.04 mM lost over 100 h). Conversely, stream water DIC concentrations were much greater than DOC (0.35-0.7 mM) and increased with nominal travel time through the hyporheic zone (0.2-0.4 mM gained over 100 h). DOC in stream water could only account for 10% of the observed increase in DIC. In situ metabolic processing of buried particulate organic matter as well as advection of CO2 from the vadose zone likely accounted for the remaining 90% of the increase in DIC. Overall, the hyporheic zone was a source of DIC to the stream. We suggest that, in mountain stream networks, hyporheic exchange facilitates the transformation of particulate organic carbon buried in floodplains and transports the DIC that is produced back to the stream where it can be evaded to the atmosphere.

  7. Using long-term data sets to understand transit times in contrasting headwater catchments

    NASA Astrophysics Data System (ADS)

    Hrachowitz, M.; Soulsby, C.; Tetzlaff, D.; Dawson, J. J. C.; Dunn, S. M.; Malcolm, I. A.

    2009-04-01

    SummaryLong-term tracer data collected over an 8 year period were analyzed to explore the transit times of two small (˜1 km 2), contrasting headwater catchments in the uplands of Scotland. At Loch Ard, the catchment was characterized by low permeability gleyed soils overlying metamorphic geology. At Sourhope, more freely draining podzolic soils were dominant, which mantled fractured and faulted volcanic rocks. Hydrometric data and chemically-based hydrograph separations indicated that Loch Ard was a flashy catchment dominated by runoff processes in the upper soil horizons. In contrast, around 77% of annual flow at Sourhope was sustained by well-buffered groundwater sources. Weekly Cl - time series in precipitation and stream flow revealed similar variability in inputs at both sites, but much greater damping in outputs at Sourhope. Despite this, both catchments filtered white noise frequencies in precipitation inputs into 1/ f outputs. These input-output relationships were modeled with a range of transit time distributions (TTD). At the responsive Loch Ard catchment, mean transit times (MTT) for the study period were estimated at 135-202 days. Models based on a gamma distribution or two parallel linear reservoirs were best able to capture the short- and long-term fluctuations in stream water in response to input variations. At Sourhope, the highly damped tracer signal in stream waters was poorly captured by all the TTDs used. Resulting MTT estimates of 1830-1970 days are based on weak model fits and poorly identifiable parameter sets, indicating that natural tracers such as Cl - are inadequate for catchments where MTTs are greater than a few years. At both sites, estimates of MTT using moving windows over the 8 year data sets revealed sensitivity to precipitation amounts and the length of monitoring period. It is concluded that time series of around 4 years are required to adequately constrain MTT estimates.

  8. Hydrogeologic comparison of an acidic-lake basin with a neutral-lake basin in the West-Central Adirondack Mountains, New York

    USGS Publications Warehouse

    Peters, N.E.; Murdoch, Peter S.

    1985-01-01

    Two small headwater lake basins that receive similar amounts of acidic atmospheric deposition have significantly different lake outflow pH values; pH at Panther Lake (neutral) ranges from about 4.7 to 7; that at Woods Lake (acidic) ranges from about 4.3 to 5. A hydrologic analysis, which included monthly water budgets, hydrograph analysis, examination of flow duration and runoff recession curves, calculation of ground-water storage, and an analysis of lateral flow capacity of the soil, indicates that differences in lakewater pH can be attributed to differences in the ground-water contribution to the lakes. A larger percentage of the water discharged from the neutral lake is derived from ground water than that from the acidic lake. Ground water has a higher pH resulting from a sufficiently long residence time for neutralizing chemical reactions to occur with the till. The difference in ground-water contribution is attributed to a more extensive distribution of thick till (<3m) in the neutral-lake basin than in the acidic-lake basin; average thickness of till in the neutral-lake basin is 24m whereas that in the other is 2.3m. During the snowmelt period, as much as three months of accumulated precipitation may be released within two weeks causing the lateral flow capacity of the deeper mineral soil to be exceeded in the neutral-lake basin. This excess water moves over and through the shallow acidic soil horizons and causes the lakewater pH to decrease during snowmelt.Two small headwater lake basins that receive similar amounts of acidic atmospheric deposition have significantly different lake outflow pH values; pH at Panther Lake (neutral) ranges from about 4. 7 to 7; that at Woods Lake (acidic) ranges from about 4. 3 to 5. A hydrologic analysis, which included monthly water budgets, hydrograph analysis, examination of flow duration and runoff recession curves, calculation of ground-water storage, and an analysis of lateral flow capacity of the soil, indicates that

  9. Fine-scale population structure and riverscape genetics of brook trout (Salvelinus fontinalis) distributed continuously along headwater channel networks

    USGS Publications Warehouse

    Kanno, Yoichiro; Vokoun, Jason C.; Letcher, Benjamin H.

    2011-01-01

    Linear and heterogeneous habitat makes headwater stream networks an ideal ecosystem in which to test the influence of environmental factors on spatial genetic patterns of obligatory aquatic species. We investigated fine-scale population structure and influence of stream habitat on individual-level genetic differentiation in brook trout (Salvelinus fontinalis) by genotyping eight microsatellite loci in 740 individuals in two headwater channel networks (7.7 and 4.4 km) in Connecticut, USA. A weak but statistically significant isolation-by-distance pattern was common in both sites. In the field, many tagged individuals were recaptured in the same 50-m reaches within a single field season (summer to fall). One study site was characterized with a hierarchical population structure, where seasonal barriers (natural falls of 1.5–2.5 m in height during summer base-flow condition) greatly reduced gene flow and perceptible spatial patterns emerged because of the presence of tributaries, each with a group of genetically distinguishable individuals. Genetic differentiation increased when pairs of individuals were separated by high stream gradient (steep channel slope) or warm stream temperature in this site, although the evidence of their influence was equivocal. In a second site, evidence for genetic clusters was weak at best, but genetic differentiation between individuals was positively correlated with number of tributary confluences. We concluded that the population-level movement of brook trout was limited in the study headwater stream networks, resulting in the fine-scale population structure (genetic clusters and clines) even at distances of a few kilometres, and gene flow was mitigated by ‘riverscape’ variables, particularly by physical barriers, waterway distance (i.e. isolation-by-distance) and the presence of tributaries.

  10. Carbon cycling and exports over diel and flood-recovery timescales in a subtropical rainforest headwater stream.

    PubMed

    Looman, Arún; Santos, Isaac R; Tait, Douglas R; Webb, Jackie R; Sullivan, Caroline A; Maher, Damien T

    2016-04-15

    Catchment headwaters comprise the majority of all stream length globally, however, carbon (C) dynamics in these systems remains poorly understood. We combined continuous measurements of pCO2 and radon ((222)Rn, a natural groundwater tracer) with discrete sampling for particulate organic, dissolved organic and inorganic carbon (POC, DOC, and DIC) to assess the short-term carbon dynamics of a pristine subtropical headwater stream in Australia, over contrasting hydrologic regimes of drought, flash-flooding and recovery. Observations over 23days revealed a shift from carbon losses dominated by CO2 outgassing under conditions of low flow (66.4±0.4% of carbon export) to downstream exports of carbon during the flood (87.8±9.7% of carbon export). DOC was the dominant form of downstream exports throughout the study (DOC:DIC:POC=0.82:0.05:0.13). The broadest diel variability among variables occurred during the drought phase, with diel variability up to 662μatmd(-1) (or 27μM[CO2*]d(-1)), 17μMd(-1) and 268Bqm(-3)d(-1) for pCO2, dissolved oxygen and (222)Rn, respectively. Diel dynamics indicated multiple interrelated drivers of stream water chemistry including groundwater seepage and in-stream metabolism. The catchment exported terrestrial carbon throughout the field campaign, with a mean net stream flux of 4.7±7.8mmolCm(-2)(catchment area)d(-1) which is equivalent to 1.4±2.3% of the estimated local terrestrial net primary production. Our observations highlight the importance of accounting for hydrological extremes when assessing the carbon budgets and ecosystem metabolism of headwater streams, and provide a first estimate of aquatic carbon exports from a pristine Australian subtropical rainforest.

  11. Radioactive Cs-137 discharge from Headwater Forested Catchment in Fukushima after Fukushima Dai-ichi Nuclear Power Plant Accident

    NASA Astrophysics Data System (ADS)

    Iwagami, S.; Onda, Y.; Tsujimura, M.; Sakakibara, K.; Konuma, R.

    2015-12-01

    Radiocesium migration from headwater forested catchment is important perception as output from the forest which is also input to the subsequent various land use and downstream rivers after Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. In this study, Cs-137 concentration of dissolved water, suspended sediment and coarse organic matter such as leaf and branch were monitored. Discharge amount of stream water, suspended sediment and coarse organic matter were measured to investigate the discharge amount of radiocesium and composition of radiocesium discharge form through the headwater stream. Observation were conducted at stream site in four headwater catchments in Yamakiya district, located ~35 km north west of FDNPP from June 2011 (suspended sediment and coarse organic matter: August 2012) to December 2014.The Cs-137 concentration of dissolved water was around 1Bq/l at June 2011. Then declined to 0.1 Bq/l at December 2011. And in December 2014, it declined to 0.01 Bq/l order. Declining trend of Cs-137 concentration in dissolved water was expressed in double exponential model. Also temporary increase was observed in dissolved Cs-137 during the rainfall event. The Cs-137 concentration of suspended sediment and coarse organic matter were 170-49000 Bq/kg and 350-14000 Bq/kg respectably. The Cs-137 concentration of suspended sediment showed good correlation with average deposition density of catchment. The effect of decontamination works appeared in declining of Cs-137 concentration in suspended sediment. Contribution rate of Cs-137 discharge by suspended sediment was 96-99% during a year. Total annual Cs-137 discharge from the catchment were 0.02-0.3% of the deposition.

  12. Factors affecting distribution of wood, detritus, and sediment in headwater streams draining managed young-growth red alder - Conifer forests in southeast Alaska

    USGS Publications Warehouse

    Gomi, T.; Johnson, A.C.; Deal, R.L.; Hennon, P.E.; Orlikowska, E.H.; Wipfli, M.S.

    2006-01-01

    Factors (riparian stand condition, management regimes, and channel properties) affecting distributions of wood, detritus (leaves and branches), and sediment were examined in headwater streams draining young-growth red alder (Alnus rubra Bong.) - conifer riparian forests (40 years old) remained in channels and provided sites for sediment and organic matter storage. Despite various alder-conifer mixtures and past harvesting effects, the abundance of large wood, fine wood, and detritus accumulations significantly decreased with increasing channel bank-full width (0.5-3.5 m) along relatively short channel distances (up to 700 m). Changes in wood, detritus, and sediment accumulations together with changes in riparian stand characteristics create spatial and temporal variability of in-channel conditions in headwater systems. A component of alder within young-growth riparian forests may benefit both wood production and biological recovery in disturbed headwater stream channels. ?? 2006 NRC.

  13. Discriminating anthropogenic climate change from natural climate oscillation signals in dissolved organic matter export from headwater catchments.

    NASA Astrophysics Data System (ADS)

    Creed, I. F.; Girma, S.; Quick, C.

    2012-12-01

    Headwater catchments are potential sentinels for climate change because their hydrology and biogeochemistry respond to changing environmental conditions at scales appropriate to changes in both weather and climate. Scientific investigations focusing on changes in climate-driven environmental change would benefit by understanding changes in the export pattern of dissolved organic matter, "DOM signatures", from headwater catchments. However, climatic change has complex influences on headwater catchment dynamics, and to determine the effects of climate change, we must be able to discriminate between anthropogenic climate warming (non-stationary linear trends) and natural climate oscillation (stationary oscillating cycles) signals within catchment DOM yields from catchments. We present an analytical framework based on wavelet theory for analyzing non-stationary and stationary signals in yearly time series of DOM yields. This analytical framework was used to test the following hypotheses: That yearly DOM yields in headwater catchments contain both non-stationary and stationary climate signals; That non-stationary signals are greater than stationary ones; And that the effects of these signals are greater in catchments with lower rates of change in water loading and lower water storage capacity (i.e., are more directly linked to atmospheric conditions). We applied this framework on the yearly time series of DOM yield from catchments in the Turkey Lakes Watershed in Ontario, Canada and show that DOM signals appear "decoupled". In all catchments, dissolved organic carbon (DOC) showed no non-stationary (declining trends) despite showing declining yearly water yields, but catchments with relatively lower water loading (lower elevation on windward side of mountain) showed stronger and larger DOC export than those with higher water loading (high elevation on same side of mountain). In contrast, catchments showed both significant declining trends and oscillating cycles in yearly

  14. Summary of Hydrologic Data for the Tuscarawas River Basin, Ohio, with an Annotated Bibliography

    USGS Publications Warehouse

    Haefner, Ralph J.; Simonson, Laura A.

    2010-01-01

    . Although hydraulic connection between the sandstone bedrock and the sands and gravels in valleys is likely, it has not been assessed in the Tuscarawas River Basin. In 2001, the major land uses in the basin were approximately 40 percent forested, 39 percent agricultural, and 17 percent urban/residential. Between 1992 and 2001, forested land use decreased by 2 percent with correspondingly small increases in agricultural and urban land uses, but from 1980 to 2005, the 13-county area that encompasses the basin experienced a 7.1-percent increase in population. Higher population density and percentages of urban land use were typical of the northern, headwaters parts of the basin in and around the cities of Akron, Canton, and New Philadelphia; the southern area was rural. The basin receives approximately 38 inches of precipitation per year that exits the basin through evapotranspiration, streamflow, and groundwater withdrawals. Recharge to groundwater is estimated to range from 6 to 10 inches per year across the basin. In 2000, approximately 89 percent of the 116 million gallons per day of water used in the basin came from groundwater sources, whereas 11 percent came from surface-water sources. To examine directions of groundwater flow in the basin, a new dataset of water-level contours was developed by the Ohio Department of Natural Resources. The contours were compiled on a map that shows that groundwater flows from the uplands towards the valleys and that the water-level surface mimics surface topography; however, there are areas where data were too sparse to adequately map the water-level surface. Additionally, little is known about deep groundwater that may be flowing into the basin from outside the basin and groundwater interactions with surface-water bodies. Many previous reports as well as new data collected as part of this study show that water quality in the streams and aquifers in the Tuscarawas River Basin has been degraded by urban, suburban, and rural

  15. Evaluation of gridded snow water equivalent and satellite snow cover products for mountain basins in a hydrologic model

    NASA Astrophysics Data System (ADS)

    Dressler, K. A.; Leavesley, G. H.; Bales, R. C.; Fassnacht, S. R.

    2006-03-01

    The USGS precipitation-runoff modelling system (PRMS) hydrologic model was used to evaluate experimental, gridded, 1 km2 snow-covered area (SCA) and snow water equivalent (SWE) products for two headwater basins within the Rio Grande (i.e. upper Rio Grande River basin) and Salt River (i.e. Black River basin) drainages in the southwestern USA. The SCA product was the fraction of each 1 km2 pixel covered by snow and was derived from NOAA advanced very high-resolution radiometer imagery. The SWE product was developed by multiplying the SCA product by SWE estimates interpolated from National Resources Conservation Service snow telemetry point measurements for a 6 year period (1995-2000). Measured SCA and SWE estimates were consistently lower than values estimated from temperature and precipitation within PRMS. The greatest differences occurred in the relatively complex terrain of the Rio Grande basin, as opposed to the relatively homogeneous terrain of the Black River basin, where differences were small. Differences between modelled and measured snow were different for the accumulation period versus the ablation period and had an elevational trend. Assimilating the measured snowfields into a version of PRMS calibrated to achieve water balance without assimilation led to reduced performance in estimating streamflow for the Rio Grande and increased performance in estimating streamflow for the Black River basin. Correcting the measured SCA and SWE for canopy effects improved simulations by adding snow mostly in the mid-to-high elevations, where satellite estimates of SCA are lower than model estimates.

  16. The impact of land-cover change on flood peaks in peatland basins

    NASA Astrophysics Data System (ADS)

    Gao, Jihui; Holden, Joseph; Kirkby, Mike

    2016-05-01

    In headwater peatlands, saturation-excess overland flow is a dominant source of river discharge. Human modifications to headwater peatlands result in vegetation cover change but there is a lack of understanding about how the spatial distribution of such change impacts flood peaks. A fully distributed version of TOPMODEL with an overland flow velocity module was used to simulate flood response for three upland peat basins. Bare peat strips adjacent to channels resulted in a higher and faster flow peak; for a 20 mm h-1 rainfall event, with bare riparian zones covering 10% of the basin area, peaks were increased, compared to the current hydrograph, by 12.8%, 1.8%, and 19.6% in the three basins. High density Sphagnum ground cover over the same riparian zones reduced flow peaks (e.g., by 10.1%, 1.8%, and 13.4% for the 20 mm h-1 event) compared to the current hydrograph. With similar total areas of land-cover change, the size of randomly located patches of changed cover had no effect on peak flow for patch sizes up to 40,000 m2. However, cover changes on gentle slope areas generally resulted in a larger change in peak flow when compared with the same changes on steeper slopes. Considering all results for the same proportion of catchment area that undergoes change, land-cover change along narrow riparian buffer strips had the highest impact on river flow. Thus, the protection and revegetation of damaged riparian areas in upland peat catchments may be highly beneficial for flood management.

  17. Soil moisture mapping in torrential headwater catchments using a local interpolation method (Draix-Bléone field observatory, South Alps, France)

    NASA Astrophysics Data System (ADS)

    Mallet, Florian; Marc, Vincent; Douvinet, Johnny; Rossello, Philippe; Le Bouteiller, Caroline; Malet, Jean-Philippe

    2016-04-01

    Soil moisture is a key parameter that controls runoff processes at the watershed scale. It is characterized by a high area and time variability, controlled by site properties such as soil texture, topography, vegetation cover and climate. Several recent studies showed that changes in water storage was a key variable to understand the distribution of water residence time and the shape of flood's hydrograph (McDonnell and Beven, 2014; Davies and Beven, 2015). Knowledge of high frequency soil moisture variation across scales is a prerequisite for better understanding the areal distribution of runoff generation. The present study has been carried out in the torrential Draix-Bléone's experimental catchments, where water storage processes are expected to occur mainly on the first meter of soil. The 0,86 km2 Laval marly torrential watershed has a peculiar hydrological behavior during flood events with specific discharge among the highest in the world. To better understand the Laval internal behavior and to identify explanatory parameters of runoff generation, additional field equipment has been setup in sub-basins with various land use and morphological characteristics. From fall 2015 onwards this new instrumentation helped to supplement the routine measurements (rainfall rate, streamflow) and to develop a network of high frequency soil water content sensors (moisture probes, mini lysimeter). Data collected since early May and complementary measurement campaigns (itinerant soil moisture measurements, geophysical measurements) make it now possible to propose a soil water content mapping procedure. We use the LISDQS spatial extrapolation model based on a local interpolation method (Joly et. al, 2008). The interpolation is carried out from different geographical variables which are derived from a high resolution DEM (1m LIDAR) and a land cover image. Unlike conventional interpolation procedure, this method takes into account local forcing parameters such as slope, aspect

  18. Sediment and nutrient delivery from thermokarst features in the foothills of the North Slope, Alaska: Potential impacts on headwater stream ecosystems

    USGS Publications Warehouse

    Bowden, W.B.; Gooseff, M.N.; Balser, A.; Green, A.; Peterson, B.J.; Bradford, J.

    2008-01-01

    Permafrost is a defining characteristic of the Arctic environment. However, climate warming is thawing permafrost in many areas leading to failures in soil structure called thermokarst. An extensive survey of a 600 km2 area in and around the Toolik Lake Natural Research Area (TLNRA) revealed at least 34 thermokarst features, two thirds of which were new since ???1980 when a high resolution aerial survey of the area was done. Most of these thermokarst features were associated with headwater streams or lakes. We have measured significantly increased sediment and nutrient loading from thermokarst features to streams in two well-studied locations near the TLNRA. One small thermokarst gully that formed in 2003 on the Toolik River in a 0.9 km2 subcatchment delivered more sediment to the river than is normally delivered in 18 years from 132 km2 in the adjacent upper Kuparuk River basin (a long-term monitoring reference site). Ammonium, nitrate, and phosphate concentrations downstream from a thermokarst feature on Imnavait Creek increased significantly compared to upstream reference concentrations and the increased concentrations persisted over the period of sampling (1999-2005). The downstream concentrations were similar to those we have used in a long-term experimental manipulation of the Kuparuk River and that have significantly altered the structure and function of that river. A subsampling of other thermokarst features from the extensive regional survey showed that concentrations of ammonium, nitrate, and phosphate were always higher downstream of the thermokarst features. Our previous research has shown that even minor increases in nutrient loading stimulate primary and secondary production. However, increased sediment loading could interfere with benthic communities and change the responses to increased nutrient delivery. Although the terrestrial area impacted by thermokarsts is limited, the aquatic habitat altered by these failures can be extensive. If warming in

  19. The influence of high magnitude/ low frequency flood events on the spawning habitat of Atlantic salmon in the headwaters of a Scottish stream.

    NASA Astrophysics Data System (ADS)

    Moir, H.; Gibbins, C.; Soulsby, C.; Webb, J.

    2002-12-01

    In upland salmonid spawning streams, a large proportion of sediment supply is generated in steep headwater reaches during low frequency, high magnitude flood events. These events are integral in dictating channel morphology in these streams. Previous work on a number of Scottish upland streams has suggested that material introduced to the channel during these events is the dominant source of salmonid spawning-calibre sediment and, being important in dictating channel morphology through-out the system, key in controlling the distribution of fish habitats. In headwater reaches, salmonid spawning habitat tends to be limited by the quantity and distribution of suitable sediments, the hydraulics of such locations tending to transport gravel-sized material downstream. Data collected on the Allt a' Ghlinne Bhig (an upland tributary of the River Tay, Scotland) has shown that headwater accumulations of gravel as a result of episodic sediment input during large flood events can provide important spawning habitat, although such features are intrinsically unstable. Uptake of these habitats may be disproportionately important to juvenile production. The stream morphology and discharge associated with over 400 incidents of Atlantic salmon spawning were recorded over three consecutive seasons (2000, 2001 and 2002). Two high magnitude flood events in September 2001 and July 2002 resulted in major sediment input to the headwaters, heavily modifying the character of the channel and producing many substantial accumulations of gravel. In the season prior to these events (2000), no spawning was observed in these locations. During the subsequent surveys (2001 and 2002), a significant number of spawning incidents were observed in the headwaters, potentially providing stock to uptake habitat in these important headwater areas. Although stream discharge during the spawning period is known to affect access to headwater reaches, flows between the three study periods were not significantly

  20. Rhinolekos capetinga: a new cascudinho species (Loricariidae, Otothyrinae) from the rio Tocantins basin and comments on its ancestral dispersal route

    PubMed Central

    Roxo, Fábio F.; Ochoa, Luz E.; Silva, Gabriel S. C.; Oliveira, Claudio

    2015-01-01

    Abstract The present study deals with the description of a new species of Rhinolekos. It can be distinguished from its congeners by having 31 vertebrae, the anterior portion of the compound supraneural-first dorsal-fin proximal radial contacting the neural spine of the 9th vertebra, the absence of transverse dark bands in the pectoral, pelvic and anal-fin rays, 24–28 plates in the dorsal series, the lack of odontodes on the ventral tip of the snout, the absence of accessory teeth, a greater prenasal length, a smaller head length, and by a greater snout length. Rhinolekos capetinga is restricted to the headwaters of the rio Tocantins and it is the first species of this genus in the Amazon basin. Additionally, we present a brief discussion of a biogeographic scenario that may explain the dispersal of the new species from the rio Paranaíba to the rio Tocantins basin. We suggest that the ancestral lineage of Rhinolekos capetinga reached the rio Tocantins from portions of the rio Paranaíba at the end of the Miocene, about 6.3 Mya (4.1–13.9 Mya 95% HPD), probably as a result of headwater capture processes among adjacent drainages. PMID:25685034

  1. Hisonotus acuen, a new and phenotypically variable cascudinho (Siluriformes, Loricariidae, Hypoptopomatinae) from the upper rio Xingu basin, Brazil

    PubMed Central

    Silva, Gabriel S. C.; Roxo, Fábio F.; Oliveira, Claudio

    2014-01-01

    Abstract A new species of Hisonotus is described from the headwaters of the rio Xingu. The new species is distinguished from its congeners by having a functional V-shaped spinelet, odontodes not forming longitudinal aligned rows on the head and trunk, lower counts of the lateral and median series of abdominal figs, presence of a single rostral fig at the tip of the snout, absence of the unpaired figlets at typical adipose fin position, yellowish-tipped teeth, absence of conspicuous dark saddles and stripe on the body and higher number of teeth on the premaxillary and dentary. The new species, Hisonotus acuen, is restricted to headwaters of the rio Xingu basin, and is the first species of the genus Hisonotus described from the rio Xingu basin. Hisonotus acuen is highly variable in aspects of external body proportions, including body depth, snout length, and abdomen length. This variation is partly distributed within and among populations, and is not strongly correlated with body size. PCA of 83 adult specimens from six allopatric populations indicates the presence of continuous variation. Therefore, the available morphological data suggest that the individuals inhabiting the six localities of rio Xingu represent different populations of a single species. Low intraspecific variation in mitochondrial Cytochrome oxidase subunit I (COI) provides corroborative evidence. PMID:25349492

  2. Integration of the Gila River drainage system through the Basin and Range province of southern Arizona and southwestern New Mexico (USA)

    NASA Astrophysics Data System (ADS)

    Dickinson, William R.

    2015-05-01

    The Gila River and its tributaries in southern Arizona and adjoining states incorporate several dozen individual extensional basins of the central Basin and Range province into a single integrated drainage network. Forty basins in the Gila domain contain more than 1000 m (maximum ~ 3500 m) of post-12 Ma basin fill. Subsurface evaporites in many basins document internal drainages terminating in isolated playa lakes during early phases of basin history. The nature of intrabasinal and interbasinal divides and of eroded or sedimented stream passages through mountain ranges intervening between the basins reveal the geomorphic mechanisms that achieved drainage integration over late Miocene to early Pleistocene time. Drainage integration accompanied by headward erosion eastward toward Gila headwaters was a response to Miocene opening of the Gulf of California, into which the Gila River debouched directly before the Pliocene (< 5 Ma) lower course of the Colorado River was established. Residual basins of internal drainage where headward erosion has not yet penetrated into basin fill are most common in the easternmost Gila domain but also persist locally farther west. Most basin fill was dissected during drainage integration within the upstream Gila domain but continued accumulation of undissected basin fill by sediment aggradation is dominant in the downstream Gila domain. Basin dissection was initiated by Pliocene time in the central Gila domain but was delayed until Pleistocene time farther east. In the westernmost Gila domain, interaction with erosional and depositional episodes along the Colorado River influenced the development of Quaternary landscapes along the tributary Gila River. The sedimentary history of the Gila drainage network illustrates the means by which trunk rivers can establish courses across corrugated topography produced by the extensional rupture of continental blocks.

  3. Diagnosis of Hydrological Resiliency and Functional Change in a Canadian Rockies Mountain Basin

    NASA Astrophysics Data System (ADS)

    Harder, P.; Pomeroy, J. W.; Siemens, E.; Fang, X.

    2015-12-01

    A well-instrumented headwater basin in the Canadian Rockies, Marmot Creek Research Basin, has experienced substantial warming at a range of elevations with evidence of hydrological functional change, but there has been no change observed in the streamflow regime over the last 50 years. Despite observations of increased air temperature of up to 4 oC in winter, concentration of precipitation into multiple day events in the spring, decreased peak snow accumulation at lower elevations by 50%, and decreased (increased) low (high) elevation groundwater storage; there are no trends in streamflow timing, peak or seasonal volumes since records began in 1962. This suggests a remarkable resilience in runoff generation to changing temperature and precipitation regime in a cold regions basin. To diagnose possible reasons for this resilience the Cold Regions Hydrological Model (CRHM) simulated the basin hydrological processes and response over two periods that had excellent driving meteorology; 1969-1987 and 2006-2013. CRHM calculates all of the relevant hydrological processes including blowing snow redistribution, intercepted snow and rain loss, sublimation, snowmelt, evapotranspiration, infiltration into frozen and unfrozen soils, overland flow, interflow in organic soils, sub-surface runoff in mineral soils, soil water redistribution and groundwater flow. Model results show that compared to the first period, increases in annual, basin-averaged fluxes occurred in the latter period for rainfall (37%), snowfall (20%), snowmelt (30%), evapotranspiration (23%), and sublimation (42%), but no significant trend in runoff developed between the two periods. Snowmelt, sublimation and runoff increases were primarily at high elevations and sometimes reversed at lower elevations, whilst evapotranspiration and rainfall increases were at all elevations. This suggests that there are compensatory, altitude dependent increases in evaporative losses from sublimation and evapotranspiration that

  4. Levels of radioactivity in fish from streams near F-Area and H-Area seepage basins

    SciTech Connect

    Murphy, C.E. Jr.; Loehle, C.

    1991-05-01

    This report summarizes results of recent analyses of radioactivity in fish from SRS streams near the F-Area and H-Area seepage basins. Fish were collected from headwater areas of Four Mile Creek and Pen Branch, from just below the H-Area seepage basin, and from three sites downstream in Four Mile Creek. These fish were analyzed for gross alpha and gross beta radioactivity using standard EPA methods. Levels of gross alpha and nonvolatile beta radioactivity in fish were found to be comparable to levels previously reported for these sites. Gross alpha activity was not found to be influenced by Separations Area discharges. Nonvolatile beta activity was higher in the nonvolatile beta activity was attributable to Cs-137 and K-40. The dosimetric consequences of consuming fish from this area were found to be well below DOE guidelines.

  5. Structure and sediment budget of Yinggehai-Song Hong basin, South China Sea: Implications for Cenozoic tectonics and river basin reorganization in Southeast Asia

    NASA Astrophysics Data System (ADS)

    Lei, Chao; Ren, Jianye; Sternai, Pietro; Fox, Matthew; Willett, Sean; Xie, Xinong; Clift, Peter D.; Liao, Jihua; Wang, Zhengfeng

    2015-08-01

    The temporal link between offshore stratigraphy and onshore topography is of key importance for understanding the long-term surface evolution of continental margins. Here we present a grid of regional, high-quality reflection seismic and well data to characterize the basin structure. We identify fast subsidence of the basin basement and a lack of brittle faulting of the offshore Red River fault in the Yinggehai-Song Hong basin since 5.5 Ma, despite dextral strike-slip movement on the onshore Red River fault. We calculate the upper-crustal, whole-crustal, and whole-lithospheric stretching factors for the Yinggehai-Song Hong basin, which show that the overall extension observed in the upper crust is substantially less than that observed for the whole crust or whole lithosphere. We suggest that fast basement subsidence after 5.5 Ma may arise from crustal to lithospheric stretching by the regional dynamic lower crustal/mantle flow originated by collision between India-Eurasia and Indian oceanic subduction below the Eurasian margin. In addition, we present a basin wide sediment budget in the Yinggehai-Song Hong basin to reconstruct the sedimentary flux from the Red River drainage constrained by high-resolution age and seismic stratigraphic data. The sediment accumulation rates show a sharp increase at 5.5 Ma, which suggests enhanced onshore erosion rates despite a slowing of tectonic processes. This high sediment supply filled the accommodation space produced by the fast subsidence since 5.5 Ma. Our data further highlight two prominent sharp decreases of the sediment accumulation at 23.3 Ma and 12.5 Ma, which could reflect a loss of drainage area following headwater capture from the Paleo-Red River. However, the low accumulation rate at 12.5 Ma also correlates with drier and therefore less erosive climatic conditions.

  6. Mobilization of optically invisible dissolved organic matter in response to rainstorm events in a tropical forest headwater river

    NASA Astrophysics Data System (ADS)

    Pereira, Ryan; Isabella Bovolo, C.; Spencer, Robert G. M.; Hernes, Peter J.; Tipping, Edward; Vieth-Hillebrand, Andrea; Pedentchouk, Nikolai; Chappell, Nick A.; Parkin, Geoff; Wagner, Thomas

    2014-02-01

    This study emphasizes the importance of rainstorm events in mobilizing carbon at the soil-stream interface from tropical rainforests. Half-hourly geochemical/isotopic records over a 13.5 h period from a 20 km2 tropical rainforest headwater in Guyana show an order of magnitude increase in dissolved organic carbon (DOC) concentration in less than 30 mins (10.6-114 mg/L). The composition of DOC varies significantly and includes optically invisible dissolved organic matter (iDOM) that accounts for a large proportion (4-89%) of the total DOC, quantified using size exclusion chromatography (SEC). SEC suggests that iDOM is comprised of low molecular weight organic moieties, which are likely sourced from fresh leaf litter and/or topsoil, as shown in soils from the surrounding environment. Although poorly constrained at present, the presence of iDOM further downstream during the wet season suggests that this organic matter fraction may represent an unquantified source of riverine CO2 outgassing in tropical headwaters, requiring further consideration.

  7. Distribution of Brook Trout and Their Food Sources in Meadow vs. Wooded Areas of Sierra Nevada Headwater Streams

    NASA Astrophysics Data System (ADS)

    Basile, N. J.; Blumenshine, S.

    2005-05-01

    Stocked eastern brook trout are now well established in historically fishless, small headwater streams in the Sierra Nevada. Although non-native, brook trout have maintained healthy populations since stocking ended 60-80 years ago. Our primary research question was whether brook trout distribution and feeding ecology is influenced by variation in headwater stream habitats and food sources. Stream habitat characteristics and trout demographic data were collected during June and August 2004 from four forested and three meadow sites among five tributaries to Bull Creek in the Sierra Nevada. Both mean fish mass and total fish biomass were greater in forested versus meadow reaches. Macroinvertebrate drift rate did not differ between meadow versus wooded reaches, but were greater in June than August. However, despite higher fish biomass, trout in forests apparently selected prey from drift, whereas trout diets in meadows reflected availability in drift. The results of this research will ultimately be used in a larger, collaborative, whole-ecosystem study conducted by the USDA-Forest Service addressing how current forest management practices affect stream ecosystems.

  8. Understanding drivers of the export of dissolved organic carbon from a German headwater catchment using Generalised Additive Models

    NASA Astrophysics Data System (ADS)

    Selle, Benny; Musolff, Andreas; Tittel, Jörg

    2016-04-01

    In the literature, several causes of recently increasing concentrations of dissolved organic carbon (DOC) in headwaters across eastern North America and northern and central Europe have been debated. One likely driver of the widespread increase of DOC concentrations since the early 1990s are decreasing depositions of acid rain resulting in an increased solubility of organic carbon compounds including humic acids. Here, we tested the hypothesis if the reduced availability of nitrate stimulated the microbial reduction of ferric iron soil minerals and the mobilisation of DOC. Forested catchments are relatively unaffected by agricultural and urban nitrate inputs. In these catchments, decreasing depositions often resulted in a reduced availability of nitrate, which are preferred electron acceptors in microbial decomposition processes. As ferric iron minerals act as efficient sorbents of organic compounds in soils its reduction may cause a release of humic substances and hence an export of DOC. To test this hypothesis, time series of DOC, dissolved iron and nitrate from a forested headwater catchment in Germany were examined using Generalised Additive Models. We found that rising DOC concentrations most likely resulted from a reductive dissolution of iron(III) minerals in soils and the associated mobilisation of adsorbed organic carbon. Phosphate, which can trigger undesired algal growth and is also known to be adsorbed by particulate iron(III), was released as well.

  9. When the entire landscape is riparian: the challenges to understanding and modeling ecosystem dynamics in lowland headwaters

    NASA Astrophysics Data System (ADS)

    Bernhardt, E. S.; Poole, G.; Ardon, M.; Helton, A. M.; Morse, J. L.; Payn, R.; Burgin, A. J.

    2011-12-01

    In the low relief landscapes of the southeastern coastal plain, headwater ecosystems have ill defined channels and lack visible valleys. The links between rivers and their floodplains in such landscapes are so spatially extensive that many headwaters in this region are classified as stream swamps or riverine wetlands. Frequently flooded soils are highly organic and drain slowly so that the water table often rises above the ground surface. Hydrologic flowpaths through the riparian zone are thus quite different from upland systems and are often dominated by lateral surface water connections, while the vertical movement of the water table is a critical control over biogeochemical function within all landscape patches. Linking the variation in vertical hydrologic connectivity to biogeochemical function at the patch scale and setting patch dynamics into a landscape level hydrologic context are ultimately necessary steps towards building a mechanistic, ecosystem-level understanding of these extensive coastal habitats. In this talk I will discuss our progress in developing conceptual and empirical models of riverine wetland biogeochemistry based upon four years of intensive observational and experimental research in a large (440ha) restored coastal plain wetland in the North Carolina coastal plain.

  10. Channel and perennial flow initiation in headwater streams: management implications of variability in source-area size.

    PubMed

    Jaeger, Kristin L; Montgomery, David R; Bolton, Susan M

    2007-11-01

    Despite increasing attention to management of headwater streams as sources of water, sediment, and wood to downstream rivers, the extent of headwater channels and perennial flow remain poorly known and inaccurately depicted on topographic maps and in digital hydrographic data. This study reports field mapping of channel head and perennial flow initiation locations in forested landscapes underlain by sandstone and basalt lithologies in Washington State, USA. Contributing source areas were delineated for each feature using a digital elevation model (DEM) as well as a Global Positioning System device in the field. Systematic source area-slope relationships described in other landscapes were not evident for channel heads in either lithology. In addition, substantial variability in DEM-derived source area sizes relative to field-delineated source areas indicates that in this area, identification of an area-slope relationship, should one even exist, would be difficult. However, channel heads and stream heads, here defined as the start of perennial flow, appear to be co-located within both of the lithologies, which together with lateral expansion and contraction of surface water around channel heads on a seasonal cycle in the basalt lithology, suggest a controlling influence of bedrock springs for that location. While management strategies for determining locations of channel heads and perennial flow initiation in comparable areas could assign standard source area sizes based on limited field data collection within that landscape, field-mapped source areas that support perennial flow are much smaller than recognized by current Washington State regulations.

  11. Functional hydrologic signatures to detect first order runoff formation mechanisms on the headwater scale

    NASA Astrophysics Data System (ADS)

    Seibert, Simon P.; Zehe, Erwin; Loritz, Ralf

    2015-04-01

    The question of 'how a catchment is functioning with respect to the partitioning of precipitation (P) into discharge (Q) and evaporation (ET)' is the key issue of most quantitative hydrological assessments. Answering it can be very difficult since the response of a system is a complex and non-linear interaction of its state, structure and forcing. Moreover, the answer has a temporal dimension. On the annual or long term time scale the Budyko curve provides a simple and meaningful concept to quantify the relative contributions of Q and ET. However, on shorter time scales we are facing severe difficulties since we need to close the balances of mass- and energy. This requires assumptions, since the gradients and resistances which ultimately drive and sustain Q and ET are often unknown and/or not observable with present measurement technologies. This applies in particular for the temporal scale of individual rainfall-runoff events. A necessary first step in this context is to provide methods which help to make meaningful assumptions regarding the driving gradients and resistances which in turn, determine the partitioning of P into Q and ET. This applies in particular for quantitative hydrological assessments, comparative studies or the evaluation of large data sets where on-site knowledge and field properties are not available. To move a step forward we propose the usage of 'functional signatures'. In our contribution we introduce a set of diagnostic signatures to discriminate runoff formation mechanisms on the headwater scale. Our signatures evaluate and compare the impact of both, different measures for the state of a catchment and properties of the forcing, to the response of a system. To describe the latter we make use of event-runoff coefficients which have been extracted from time series analysis using an automated procedure. Together our signatures provide a simple framework to test for and to distinguish between storage and intensity limited runoff formation

  12. Solute and sediment export from Amazon forest and soybean headwater streams.

    PubMed

    Riskin, Shelby H; Neill, Christopher; Jankowski, KathiJo; Krusche, Alex V; McHorney, Richard; Elsenbeer, Helmut; Macedo, Marcia N; Nunes, Darlisson; Porder, Stephen

    2017-01-01

    Intensive cropland agriculture commonly increases streamwater solute concentrations and export from small watersheds. In recent decades, the lowland tropics have become the world's largest and most important region of cropland expansion. Although the effects of intensive cropland agriculture on streamwater chemistry and watershed export have been widely studied in temperate regions, their effects in tropical regions are poorly understood. We sampled seven headwater streams draining watersheds in forest (n = 3) or soybeans (n = 4) to examine the effects of soybean cropping on stream solute concentrations and watershed export in a region of rapid soybean expansion in the Brazilian state of Mato Grosso. We measured stream flows and concentrations of NO3(-) , PO4(3-) , SO4(2-) , Cl(-) , NH4(+) , Ca(2+) , Mg(2+) , Na(+) , K(+) , Al(3+) , Fe(3+) , and dissolved organic carbon (DOC) biweekly to monthly to determine solute export. We also measured stormflows and stormflow solute concentrations in a subset of watersheds (two forest, two soybean) during two/three storms, and solutes and δ(18) O in groundwater, rainwater, and throughfall to characterize watershed flowpaths. Concentrations of all solutes except K(+) varied seasonally in streamwater, but only Fe(3+) concentrations differed between land uses. The highest streamwater and rainwater solute concentrations occurred during the peak season of wildfires in Mato Grosso, suggesting that regional changes in atmospheric composition and deposition influence seasonal stream solute concentrations. Despite no concentration differences between forest and soybean land uses, annual export of NH4(+) , PO4(3-) , Ca(2+) , Fe(3+) , Na(+) , SO4(2-) , DOC, and TSS were significantly higher from soybean than forest watersheds (5.6-fold mean increase). This increase largely reflected a 4.3-fold increase in water export from soybean watersheds. Despite this increase, total solute export per unit watershed area (i.e., yield) remained

  13. Characteristics and controls of variability in soil moisture and groundwater in a headwater catchment

    NASA Astrophysics Data System (ADS)

    McMillan, H. K.; Srinivasan, M. S.

    2015-04-01

    Hydrological processes, including runoff generation, depend on the distribution of water in a catchment, which varies in space and time. This paper presents experimental results from a headwater research catchment in New Zealand, where we made distributed measurements of streamflow, soil moisture and groundwater levels, sampling across a range of aspects, hillslope positions, distances from stream and depths. Our aim was to assess the controls, types and implications of spatial and temporal variability in soil moisture and groundwater tables. We found that temporal variability in soil moisture and water table is strongly controlled by the seasonal cycle in potential evapotranspiration, for both the mean and extremes of their distributions. Groundwater is a larger water storage component than soil moisture, and this general difference increases even more with increasing catchment wetness. The spatial standard deviation of both soil moisture and groundwater is larger in winter than in summer. It peaks during rainfall events due to partial saturation of the catchment, and also rises in spring as different locations dry out at different rates. The most important controls on spatial variability in storage are aspect and distance from the stream. South-facing and near-stream locations have higher water tables and showed soil moisture responses for more events. Typical hydrological models do not explicitly account for aspect, but our results suggest that it is an important factor in hillslope runoff generation. Co-measurement of soil moisture and water table level allowed us to identify relationships between the two. Locations where water tables peaked closer to the surface had consistently wetter soils and higher water tables. These wetter sites were the same across seasons. However, patterns of strong soil moisture responses to summer storms did not correspond to the wetter sites. Total catchment spatial variability is composed of multiple variability sources, and the

  14. Estimation of pesticide and transformation product export pathways in a headwater catchment

    NASA Astrophysics Data System (ADS)

    Gassmann, Matthias; Olsson, Oliver; Stamm, Christian; Weiler, Markus; Lange, Jens; Kümmerer, Klaus

    2014-05-01

    Following their application, pesticide residues are exported towards rivers along several hydrological pathways in agricultural areas. The importance of each pathway is influenced by the substances' physico-chemical characteristics, mainly sorption and degradation. Incomplete mineralization results in the formation of transformation products (TPs) which have generally different environmental fate characteristics than their parent compounds (PCs). Therefore, the export pathways of pesticides and their transformation products towards rivers may also be different. In order to investigate this hypothesis, we extended a distributed process-based hydrological model (ZIN-AgriTra) by the environmental fate of pesticides and their TPs. The process-based nature of the model allowed for an analysis of PC and TP export pathways including overland flow, lateral preferential flow in soils and soil water flow to tile drains. The model was applied to a Swiss headwater catchment using three pesticides and their TPs as test substances. It was successfully calibrated to three sampling stations in the catchment. At the end of the simulated three-months period, most of the applied pesticides were either fully mineralized or incompletely transformed. Less than 2% of each pesticide was exported to the river as PC or TP. Although all three pesticides could be classified as slightly mobile they remained in the top soil layer during the whole period, whereas the more mobile TPs were additionally leached through the soil towards tile drains. Accordingly, PCs were exported largely by surface runoff, while a larger share of TPs was exported via tile drains. Additionally, the delayed formation and degradation of TPs led to an export under different hydrological conditions resulting in an increased subsurface export of TPs towards the end of the simulation period. A consequence of the different export pathways of PCs and TPs could be shown by an assessment of critical source areas (CSA) in the

  15. A stream sediment geochemical survey of the Ganga River headwaters in the Garhwal Himalaya

    USGS Publications Warehouse

    Mukherjee, P.K.; Purohit, K.K.; Saini, N.K.; Khanna, P.P.; Rathi, M.S.; Grosz, A.E.

    2007-01-01

    This study models geochemical and adjunct geologic data to define provinces that are favorable for radioactive-mineral exploration. A multi-element bed-sediment geochemical survey of streams was carried out in the headwaters region of the Ganga River in northern India. Overall median values for uranium and thorium (3.6 and 13.8 ppm; maxima of 4.8 and 19.0 ppm and minima of 3.1 and 12.3 ppm respectively) exceed average upper crustal abundances (2.8 and 10.7 ppm) for these radioactive elements. Anomalously high values reach up to 8.3 and 30.1 ppm in thrust zone rocks, and 11.4 and 22.5 ppm in porphyroids. At their maxima, these abundances are nearly four- and three-fold (respectively) enriched in comparison to average crustal abundances for these rock types. Deformed, metamorphosed and sheared rocks are characteristic of the main central thrust zone (MCTZ). These intensively mylonitized rocks override and juxtapose porphyritic (PH) and proterozoic metasedimentary rock sequences (PMS) to the south. Granitoid rocks, the major protoliths for mylonites, as well as metamorphosed rocks in the MCT zone are naturally enriched in radioelements; high values associated with sheared and mylonitized zones are coincident with reports of radioelement mineralization and with anomalous radon concentrations in soils. The radioelement abundance as well as REE abundance shows a northward enrichment trend consistent with increasing grade of metamorphism indicating deformation-induced remobilization of these elements. U and Th illustrate good correlation with REEs but not with Zr. This implies that zircon is not a principal carrier of U and Th within the granitoid-dominant thrust zone and that other radioelement-rich secondary minerals are present in considerable amounts. Thus, the relatively flat, less fractionated, HREE trend is also not entirely controlled by zircon. The spatial correlation of geologic boundary zones (faults, sheared zones) with geochemical and with geophysical (Rn

  16. Wood retention and transport in tropical, headwater streams, La Selva Biological Station, Costa Rica

    NASA Astrophysics Data System (ADS)

    Cadol, Daniel; Wohl, Ellen

    2010-11-01

    Wood in tropical streams has the potential to be more mobile than wood in otherwise similar temperate streams because of the warm and humid conditions that promote decay and the more frequent and flashier floods of the tropics. To test this hypothesis, we monitored all large wood pieces for 2.3 years in 10 50-m-long reaches of old-growth headwater streams in La Selva Biological Station, Costa Rica. Annual wood retention rates for pieces ranged from 0.55 to 0.91 among the sites, and retention rates by volume ranged from 0.67 to 0.99. Assuming steady state wood load, which is reasonable for La Selva, these rates are equivalent to mean residence times of 2.2-10.6 years for pieces, and 3.0-83.2 years for a volume of wood. Calculating mean residence time from the weighted average of retention rates gives an average residence time of 4.9 years for a piece of wood and 6.9 years for a volume of wood. These values are less than those reported for old-growth temperate forests, supporting our hypothesis. Mobility of individual pieces was best predicted by piece length relative to stream width ( lr, higher lr led to lower mobility), channel gradient ( s, higher s led to higher mobility), and piece integration into the channel (unattached pieces were 2.6 times more mobile than attached, ramp, or bridge pieces). Temporal variation in retention rates was well explained by variation in peak flow. All four of these factors have also been observed to influence mobility in the temperate zone. The higher mobility of wood in our study site relative to the temperate rainforest of the Pacific Northwest may be explained by the flashy and frequent floods, the high decay rate, or the branching morphology of the native trees; but differentiating the role of these factors, particularly flow and decay, will be complicated by their covariation across climates.

  17. The impacts of thermokarst on sediment, organic matter, and macroinvertebrate community dynamics in arctic headwater streams

    NASA Astrophysics Data System (ADS)

    Flinn, M.; Kampman, J.; Larouche, J. R.; Bowden, W. B.

    2010-12-01

    Recent research has documented changes in arctic climate that influence permafrost degradation and the incidence of thermokarst formation. In 2009 and 2010, we examined several thermokarst failures on headwater streams near Toolik Lake, AK, and the Kelly River area of the Noatak National Preserve, AK, USA. We quantified significant differences between reference (upstream) and impacted stream reaches affected by these thermokarst features. Sediment deposition at Toolik in 2009, measured with sediment traps, showed no differences in the organic fractions; however, the inorganic fraction was ~2x higher (P<0.05) in the impacted reaches. In 2010, when discharge was lower and less flashy, the pattern reversed and only organic fractions varied between the impacted and reference reach. The patterns of benthic organic matter and fine sediment (stovepipe core) generally showed a 2-fold increase in the impacted reaches indicating that impacts may have a legacy over several years. Significant increases of ammonium (P<0.05) and benthic chlorophyll-a (P<0.01, rock scrubs) were significantly higher in the impacted reaches and increased sharply downstream of the thermokarst, especially in late summer (2009). Benthic macroinvertebrates showed a variable response in abundance and biomass in the impacted reaches. Collector-gatherers (Diptera, Chironomidae) abundance and biomass doubled in the impacted reaches by late summer, mostly due to Dicrotopus, Psudokiefferiella, and Rheotanytarsus. Nemoura (Plecoptera, Nemouridae), a shredding stonefly, abundance and biomass were over 5x higher in the impacted reaches (P<0.01). The increase in the collector-gatherer group was offset by a significant decrease in grazers. Baetis (Ephemeroptera, Baetidae) and Orthocladius (Diptera, Chironomidae) showed a 3-fold decrease in the impacted reaches (P<0.05). Results from several years of research indicate that thermokarst failures result in impacts that respond on different temporal scales. High

  18. Nitrate loading and CH4 and N2O Flux from headwater streams

    NASA Astrophysics Data System (ADS)

    Schade, J. D.; Bailio, J.; McDowell, W. H.

    2015-12-01

    Freshwater ecosystems transport and process significant amounts of terrestrial carbon and can be considerable sources of CO2, CH4, and N2O. A great deal of uncertainty, however, remains in both global estimates and our understanding of drivers of freshwater greenhouse gas emissions. Furthermore, small headwater streams have received insufficient attention to date and may contribute disproportionately to global GHG flux. Our objective was to quantify GHG flux and assess the impact of changes in DOC and NO3 concentrations in surface and subsurface water on flux rates in three streams in the Lamprey River watershed in New Hampshire, USA, that contrast in surface water DOC:NO3. We measured DOC, NO3 and dissolved gas concentrations in surface waters of each stream monthly from May 2011 to April 2012. Empirical measurements of reaeration coefficients were used to convert dissolved gas concentrations to fluxes. We found higher GHG concentrations and fluxes in the two streams with high DOC concentrations, particularly gases produced by anaerobic metabolism (CH4, N2O from methanogenesis and denitrification, respectively). The stream with high DOC and high NO3 showed high N2O and low CH4 flux, while the high DOC, low NO3 stream showed high CH4 and low N2O flux. Our results are consistent with a model in which C inputs drive total GHG production, while NO3 input regulates the relative importance of CH4 and N2O by suppressing methanogenesis and stimulating denitrification. The magnitude of GHG fluxes suggests that streams in this region are likely to be small sources of CO2, but potentially important sources of CH4 and N2O. Since CH4 and N2O are many times more powerful than CO2 at trapping heat in the atmosphere, freshwater emissions of these gases have the potential to offset a significant proportion of the climate benefits of the terrestrial carbon sink, a possibility that has not been sufficiently incorporated into climate models.

  19. Nitrate loading and CH4 and N2O Flux from headwater streams

    NASA Astrophysics Data System (ADS)

    Sousa, C. H. R. D.; Hilker, T.; Hall, F. G.; Moura, Y. M.; McAdam, E.

    2014-12-01

    Freshwater ecosystems transport and process significant amounts of terrestrial carbon and can be considerable sources of CO2, CH4, and N2O. A great deal of uncertainty, however, remains in both global estimates and our understanding of drivers of freshwater greenhouse gas emissions. Furthermore, small headwater streams have received insufficient attention to date and may contribute disproportionately to global GHG flux. Our objective was to quantify GHG flux and assess the impact of changes in DOC and NO3 concentrations in surface and subsurface water on flux rates in three streams in the Lamprey River watershed in New Hampshire, USA, that contrast in surface water DOC:NO3. We measured DOC, NO3 and dissolved gas concentrations in surface waters of each stream monthly from May 2011 to April 2012. Empirical measurements of reaeration coefficients were used to convert dissolved gas concentrations to fluxes. We found higher GHG concentrations and fluxes in the two streams with high DOC concentrations, particularly gases produced by anaerobic metabolism (CH4, N2O from methanogenesis and denitrification, respectively). The stream with high DOC and high NO3 showed high N2O and low CH4 flux, while the high DOC, low NO3 stream showed high CH4 and low N2O flux. Our results are consistent with a model in which C inputs drive total GHG production, while NO3 input regulates the relative importance of CH4 and N2O by suppressing methanogenesis and stimulating denitrification. The magnitude of GHG fluxes suggests that streams in this region are likely to be small sources of CO2, but potentially important sources of CH4 and N2O. Since CH4 and N2O are many times more powerful than CO2 at trapping heat in the atmosphere, freshwater emissions of these gases have the potential to offset a significant proportion of the climate benefits of the terrestrial carbon sink, a possibility that has not been sufficiently incorporated into climate models.

  20. Riparian and in-stream controls on nutrient concentrations and fluxes in a headwater forested stream

    NASA Astrophysics Data System (ADS)

    Bernal, S.; Lupon, A.; Ribot, M.; Sabater, F.; Martí, E.

    2015-03-01

    Headwater streams are recipients of water sources draining through terrestrial ecosystems. At the same time, stream biota can transform and retain nutrients dissolved in stream water. Yet studies considering simultaneously these two sources of variation in stream nutrient chemistry are rare. To fill this gap of knowledge, we analyzed stream water and riparian groundwater concentrations and fluxes as well as in-stream net uptake rates for nitrate (NO3-), ammonium (NH4+), and soluble reactive phosphorus (SRP) along a 3.7 km reach on an annual basis. Chloride concentrations (used as conservative tracer) indicated a strong hydrological connection at the riparian-stream interface. However, stream and riparian groundwater nutrient concentrations showed a moderate to null correlation, suggesting high in-stream biogeochemical processing. In-stream net nutrient uptake (Fsw) was highly variable across contiguous segments and over time, but its temporal variation was not related to the vegetative period of the riparian forest. For NH4+, the occurrence of Fsw > 0 μg N m-1 s-1 (gross uptake > release) was high along the reach, while for NO3-, the occurrence of Fsw < 0 μg N m-1 s-1 (gross uptake < release) increased along the reach. Within segments and dates, Fsw, whether negative or positive, accounted for a median of 6, 18, and 20% of the inputs of NO3-, NH4+, and SRP, respectively. Whole-reach mass balance calculations indicated that in-stream net uptake reduced stream NH4+ flux up to 90%, while the stream acted mostly as a source of NO3- and SRP. During the dormant period, concentrations decreased along the reach for NO3-, but increased for NH4+ and SRP. During the vegetative period, NH4+ decreased, SRP increased, and NO3- showed a U-shaped pattern along the reach. These longitudinal trends resulted from the combination of hydrological mixing with terrestrial inputs and in-stream nutrient processing. Therefore, the assessment of these two sources of variation in stream

  1. Examining the effects of forest thinning on runoff responses at different catchments scales in forested headwaters

    NASA Astrophysics Data System (ADS)

    Dung, B. X.; Gomi, T.; Onda, Y.; Kato, H.; Hiraoka, M.

    2012-12-01

    We conducted field observation in nested headwater catchments draining Japanese cypress (Chamaecyparis obtusa) and cedar (Cryptomeria japonica) forests at Tochigi prefectures for examining the effects of forest thinning on runoff generation at different catchment scales. 50% of the stems was removed with line thinning in catchment K2 (treatment catchment), while catchment K3 remained untreated as a control. We also monitored nested catchments within K2-1 (17.1 ha) as K2-2 (10.2 ha), K2-3 (3.7 ha) and K2-4 (5.1 ha), and within K3-1 (8.9 ha) as K3-2 (3.0 ha). Runoff from the catchments was monitored during the pre-thinning (from April, 2010 to May 2011), and the post-thinning periods (from June 2011 to July 2012). Paired-catchment and hydrograph separation analysis were used to evaluate the effects of forest thinning on runoff generation at different catchment scales. We developed the pre-thinning calibration equation for predicting post-thinning responses. Paired-catchment analysis revealed that annual catchment runoff increased 648 mm in K2-1, 414 mm in K2-2, 517 mm in K2-3 and 487 mm in K2-4 after the thinning. Both quick and delayed runoff components only increased significantly in the larger catchments of K2-1 and K2-2, while only delayed runoff components of smaller catchments (K2-3 and K2-4) increased significantly during the post-thinning period. Increases of quick runoff in large catchments could be associated with quick runoff response to soil surface compaction by line thinning and skid trail installation. Increases of delayed runoff in small catchment may be associated with increase in net precipitation and decrease in evapotranspiration. Our finding showed that changes in internal hydrological flow pathways and associated changes in runoff components due to forest harvesting differ depending on the catchment sizes.

  2. Long-term amelioration of acidity accelerates decomposition in headwater streams.

    PubMed

    Jenkins, Gareth B; Woodward, Guy; Hildrew, Alan G

    2013-04-01

    The secondary production of culturally acidified streams is low, with a few species of generalist detritivores dominating invertebrate assemblages, while decomposition processes are impaired. In a series of lowland headwater streams in southern England, we measured the rate of cellulolytic decomposition and compared it with values measured three decades ago, when anthropogenic acidification was at its peak. We hypothesized that, if acidity has indeed ameliorated, the rate of decomposition will have accelerated, thus potentially supporting greater secondary production and the longer food chains that have been observed in some well-studied recovering freshwater systems. We used cellulose Shirley test cloth as a standardized bioassay to measure the rate of cellulolytic decomposition, via loss in tensile strength, for 31 streams in the Ashdown Forest over 7 days in summer 2011 and 49 days in winter 2012. We compared this with data from an otherwise identical study conducted in 1978 and 1979. In a secondary study, we determined whether decomposition followed a linear or logarithmic decay and, as Shirley cloth is no longer available, we tested an alternative in the form of readily available calico. Overall mean pH had increased markedly over the 32 years between the studies (from 6.0 to 6.7). In both the previous and contemporary studies, the relationship between decomposition and pH was strongest in winter, when pH reaches a seasonal minimum. As in the late 1970s, there was no relationship in 2011/2012 between pH and decay rate in summer. As postulated, decomposition in winter was significantly faster in 2011/2012 than in 1978/1979, with an average increase in decay rate of 18.1%. Recovery from acidification, due to decreased acidifying emissions and deposition, has led to an increase in the rate of cellulolytic decomposition. This response in a critical ecosystem process offers a potential explanation of one aspect of the limited biological recovery that has been

  3. Post-Wildfire Impacts on Snow Accumulation and Melt: Hydrologic Implications for Headwater Catchments

    NASA Astrophysics Data System (ADS)

    Gleason, K. E.; Nolin, A. W.; Roth, T. R.

    2012-12-01

    disappeared several weeks earlier than in the unburned forest, mainly due to the substantial decrease in snow albedo. We discuss the hydrologic implications for headwater catchments in the West.

  4. The hydrological response of a rocky head water basin to convective rainfalls

    NASA Astrophysics Data System (ADS)

    Gregoretti, Carlo; Bernard, Martino; Degetto, Massimo; Matteo, Berti; Alessandro, Simoni; Stefano, Lanzoni

    2015-04-01

    A sharp-crested weir is installed at the outlet (altitude 1770 m a.s.l) of a rocky channel incised on the walls of Dimai Peak in the area of Fiames (Cortina d'Ampezzo, Dolomites-North Eastern Italian Alps) at the purpose of measuring runoff discharges. The area of the headwater basin is just 0.032 km2 but sub-vertical cliffs are capable to generate notable discharge during severe rainstorms. Due to the severe environment only five runoff events were measured (two times the facility was destroyed by rock falls and avalanches; other times failure of sensors stopped the measurements). Hydrological response is characterized by peaked hydrographs with very high rising limb. A kinematic distributed hydrological model was used to simulate the response of the basin to the convective rainfalls with the help of two rain gauges placed upstream the basin head and downstream the outlet respectively. The hydrological model uses an hortonian simplified law for determining excess rainfall and satisfactorily simulates the measured hydrographs. Such measurements are important for the understanding the hydrological response of a rocky basin to a convective rainfall. Their modeling are important as well when focused on predicting both flash floods in mountain torrents and the triggering conditions and magnitude of runoff generated debris flows.

  5. Li-Zn-Pb multi isotopic characterization of the Loire River Basin, France

    NASA Astrophysics Data System (ADS)

    Millot, R.; Desaulty, A.; Widory, D.; Bourrain, X.

    2013-12-01

    The Loire River in France is approximately 1010 km long and drains an area of 117 800 km2. Upstream, the Loire River flows following a south to north direction from the Massif Central down to the city of Orléans, 650 km from its source. The Loire River is one of the main European riverine inputs to the Atlantic Ocean. Over time, its basin has been exposed to numerous sources of anthropogenic metal pollutions, such as metal mining, industry, agriculture and domestic inputs. The Loire River basin is thus an excellent study site to develop new isotope systematics for tracking anthropogenic sources of metal pollutions (Zn and Pb) and also to investigate Li isotope tracing that can provide key information on the nature of weathering processes at the Loire River Basin scale. Preliminary data show that Li-Zn-Pb concentrations and isotopic compositions span a wide range in river waters of the Loire River main stream and the main tributaries. There is a clear contrast between the headwaters upstream and rivers located downstream in the lowlands. In addition, one of the major tributaries within the Massif Central (the Allier River) is clearly influenced by inputs resulting from mineralizations and thermomineral waters. The results showed that, on their own, each of these isotope systematics reveals important information about the geogenic or anthropogenic origin Li-Zn-Pb. Considered together, they are however providing a more integrated understanding of the overall budgets of these elements at the scale of the Loire River Basin.

  6. Water quality monitoring: the basis for watershed management in the Oldman River Basin, Canada.

    PubMed

    Koning, C W; Saffran, K A; Little, J L; Fent, L

    2006-01-01

    The Oldman River flows 440 km from its headwaters in south-western Alberta, through mountains, foothills and plains into the South Saskatchewan River. Peak flows occur in May and June. Three major reservoirs, together with more than a dozen other structures, supply water to nine irrigation districts and other water users in the Oldman basin. Human activity in the basin includes forestry, recreation, oil and gas development, and agriculture, including a large number of confined livestock feeding operations. Based on the perception of basin residents that water quality was declining and of human health concern, the Oldman River Basin Water Quality Initiative was formed in 1997 to address the concerns. There was limited factual information, and at the time there was a desire for finger pointing. Results (1998-2002) show that mainstem water quality remains good whereas tributary water quality is more of a challenge. Key variables of concern are nutrients, bacteria and pesticides. Point source discharges are better understood and better regulated, whereas non-point source runoff requires more attention. Recent data on Cryptosporidium and Giardia species are providing benefit for focusing watershed management activities. The water quality data collected is providing a foundation to implement community-supported urban and rural better management practices to improve water quality.

  7. Pareiorhina hyptiorhachis, a new catfish species from Rio Paraíba do Sul basin, southeastern Brazil (Siluriformes, Loricariidae)

    PubMed Central

    Silva, Gabriel de Souza da Costa e; Roxo, Fábio Fernandes; Oliveira, Claudio

    2013-01-01

    Abstract Pareiorhina hyptiorhachis is described from Ribeirão Fernandes and Rio Pomba, Rio Paraíba do Sul basin, Brazil. The new species is distinguished from its congeners (Pareiorhina brachyrhyncha, Pareiorhina carrancas, Pareiorhina cepta, and Pareiorhina rudolphi) by the presence of a conspicuous ridge on the trunk posterior to the dorsal fin (postdorsal ridge), simple teeth, a completely naked abdomen, a round dorsal profile of the head, greater suborbital depth and greater head width. We discuss the distributional pattern of the new species and its congeners and hypothesize that headwater capture is responsible for the distribution of Pareiorhina species across different watersheds in southeastern of Brazil. PMID:23878510

  8. Climate change impacts in the Euphrates-Tigris Basin based on different model and scenario simulations

    NASA Astrophysics Data System (ADS)

    Bozkurt, Deniz; Sen, Omer Lutfi

    2013-02-01

    SummaryHydro-climatic effects of future climate change in the Euphrates-Tigris Basin are investigated using dynamically downscaled outputs of different GCM (ECHAM5, CCSM3 and HadCM3) - emissions scenario (A1FI, A2 and B1) simulations. The suite of simulations (total five) enables an analysis taking into account the A2 emission scenario simulations of three different GCMs and another analysis based on the three different emissions scenario (A1FI, A2 and B1) simulations of one GCM (CCSM3). All scenario simulations indicate winter surface temperature increases in the entire basin, however, the increase is larger in the highlands. The greatest increase in the annual temperature by the end of century belongs to the CCSM3 A1FI simulation with an increment of 6.1 °C in the highlands. There is a broad agreement amongst the simulations in terms of the winter precipitation decrease in the highlands and northern parts and increase in the southern parts of the basin. A remarkable impact of warming could be seen on the snow water equivalent in the highlands where each simulation points out statistically significant decreases ranging from 55% (lower emissions) to 87% (higher emissions). Statistically significant declines (25-55%) are found for the annual surface runoff of the main headwaters area. Moreover, significant temporal shifts to earlier days (between 18 and 39 days depending on the scenario) are projected to occur in the surface runoff timing in the headwaters region. Projected annual surface runoff changes in all simulations suggest that the territories of Turkey and Syria within the basin are most vulnerable to climate change as they will experience significant decreases in the annual surface runoff. Eventually, however, the downstream countries, especially Iraq, may suffer more as they rely primarily on the water released by the upstream countries. The substantial changes in the hydro-climate of the basin, therefore, are likely to increase the challenges associated

  9. Biomass of coastal cutthroat trout in unlogged and previously clearcut basins in the central Coast Range of Oregon

    USGS Publications Warehouse

    Connolly, P.J.; Hall, J.D.

    1999-01-01

    Populations of coastal cutthroat trout Oncorhynchus clarki clarki were sampled in 16 Oregon headwater streams during 1991–1993. These streams were above upstream migration barriers and distributed among basins that had been logged 20–30 and 40–60 years ago and basins that had not been logged but had burned 125–150 years ago. The objective of our study was to characterize the populations and habitats of age-1 or older cutthroat trout within these three forest management types. Streams within unlogged basins had relatively low levels and a small range of trout biomass (g/m2). Streams in basins logged 40–60 years ago supported low levels but an intermediate range of trout biomass. Streams in basins logged 20–30 years ago supported the widest range of biomass, including the lowest and highest biomasses among all streams sampled. The variable that best explained the variation of trout biomass among all 16 streams was the amount of large woody debris (LWD). All streams were heavily shaded during at least part of the year by mostly closed tree canopies. Deciduous trees were more prominent in canopies over streams in logged basins, while conifers were more prominent in the stream canopies of unlogged basins. Our results suggest that trout production in basins extensively clear-cut 20–60 years ago may generally decrease or remain low over the next 50 or more years because of decreasing loads of remnant LWD, persistent low recruitment potential for new LWD, and persistent heavy shading by conifers. These logged basins are not likely to show an increase in trout biomass over the next 50 years unless reset by favorable natural disturbances or by habitat restoration efforts.

  10. Biomass of coastal cutthroat trout in unlogged and previously clear-cut basins in the central Coast Range of Oregon

    USGS Publications Warehouse

    Connolly, P.J.; Hall, J.D.

    1999-01-01

    Populations of coastal cutthroat trout Oncorhynchus clarki clarki were sampled in 16 Oregon headwater streams during 1991-1993. These streams were above upstream migration barriers and distributed among basins that had been logged 20-30 and 40-60 years ago and basins that had not been logged but had burned 125-150 years ago. The objective of our study was to characterize the populations and habitats of age-1 or older cutthroat trout within these three forest management types. Streams within unlogged basins had relatively low levels and a small range of trout biomass (g/m2). Streams in basins logged 40-60 years ago supported low levels but an intermediate range of trout biomass. Streams in basins logged 20-30 years ago supported the widest range of biomass, including the lowest and highest biomasses among all streams sampled. The variable thai best explained the variation of trout biomass among all 16 streams was the amount of large woody debris (LWD). All streams were heavily shaded during at least part of the year by mostly closed tree canopies. Deciduous trees were more prominent in canopies over streams in logged basins, while conifers were more prominent in the stream canopies of unlogged basins. Our results suggest that trout production in basins extensively clear-cut 20-60 years ago may generally decrease or remain low over the next 50 or more years because of decreasing loads of remnant LWD, persistent low recruitment potential for new LWD, and persistent heavy shading by conifers. These logged basins are not likely to show an increase in trout biomass over the next 50 years unless reset by favorable natural disturbances or by habitat restoration efforts.

  11. Hydrological behaviour of sub-Mediterranean alpine headwater streams in a badlands environment

    NASA Astrophysics Data System (ADS)

    Cras, A.; Marc, V.; Travi, Y.

    2007-06-01

    SummaryInvestigations of flash floods generation processes are very few compared with studies in humid areas. The rapidity and intensity of these processes make difficult any data acquisition on the field. The present study aims to improve our knowledge on these environments by using the facilities of the Draix ERBs (Southern French Alps) where well-documented black marls show a typical badlands morphology with V-shaped gullies. Time-varying components of total flow and flow sources have been investigated from a long-term isotopic and hydrochemical survey of rainwaters, overland waters, soil waters and streamwaters. We present in greater detail two flood events which occurred in three adjacent basins and had contrasting antecedent soil moisture conditions. Isotopic data were used to apply time-based hydrograph separations. Due to the very short transfer time of waters, convolution of the rainfall isotopic signal with a two-parameter transfer function (dispersive transfer function) proved the best way to assess the event isotopic concentration. End Members Mixing Analysis (EMMA) has been carried out using non reactive chemical species to get source areas of runoff. New water participation by direct surface transfer was the main mechanism at the peak discharge. This contribution was found to dominate irrespective of whether the antecedent soil moisture was dry or wet. Nevertheless, up to 20% of subsurface water has been observed at peak discharge for dry pre-event conditions. During the flow recession phases, this subsurface water contribution was greater for wet antecedent conditions. In dry initial conditions, subsurface water was mostly new water, whereas in wet conditions pre-event water could contribute to the flow. A deep groundwater reservoir may take part in the pre-event component in the larger basin but in the smaller basins pre-event water was mostly made of short residence time water (from previous rainfall events) originating from sporadic, highly

  12. Impact of land use changes on water quality in headwaters of the Three Gorges Reservoir.

    PubMed

    Yang, Huicai; Wang, Guoqiang; Wang, Lijing; Zheng, Binghui

    2016-06-01

    The assessment of spatial and temporal variation of water quality influenced by land use is necessary to manage the environment sustainably in basin scales. Understanding the correlations between land use and different formats of nonpoint source nutrients pollutants is a priority in order to assess pollutants loading and predicting the impact on surface water quality. Forest, upland, paddy field, and pasture are the dominant land use in the study area, and their land use pattern status has direct connection with nonpoint source (NPS) pollutant loading. In this study, two land use scenarios (1995 and 2010) were used to evaluate the impact of land use changes on NPS pollutants loading in basins upstream of Three Gorges Reservoir (TGR), using a calibrated and validated version of the soil and water assessment tool (SWAT) model. The Pengxi River is one of the largest tributaries of the Yangtze River upstream of the TGR, and the study area included the basins of the Dong and Puli Rivers, two major tributaries of the Pengxi River. The results indicated that the calibrated SWAT model could successfully reproduce the loading of NPS pollutants in the basins of the Dong and Puli Rivers. During the 16-year study period, the land use changed markedly with obvious increase of water body and construction. Average distance was used to measure relative distribution patterns of land use types to basin outlets. Forest was mainly distributed in upstream areas whereas other land use types, in particular, water bodies and construction areas were mainly distributed in downstream areas. The precipitation showed a non-significant influence on NPS pollutants loading; to the contrary, interaction between precipitation and land use were significant sources of variation. The different types of land use change were sensitive to NPS pollutants as well as land use pattern. The influence of background value of soil nutrient on NPS pollutants loading was evaluated in upland and paddy field. It was

  13. Impact of Mountaintop Mining/Valley Fill on the Stable Carbon Isotopic Composition and Concentration of Dissolved Organic Carbon and Dissolved Inorganic Carbon in Headwater Streams

    EPA Science Inventory

    Headwater streams are the dominant land-water interface across much of the landscape and provide many important ecological services. Cycling and transport of various carbon fractions, which serve as important food sources for downstream aquatic ecosystems, are among the important...

  14. PREDICTING THE OCCURRENCE OF NUTRIENTS AND PESTICIDES DURING BASE FLOW IN NONTIDAL HEADWATER STREAMS OF THE MID-ATLANTIC COASTAL PLAIN

    EPA Science Inventory

    Water quality in nontidal headwater (first-order) streams of the Mid-Atlantic Coastal Plain (MACP) during base flow in the late winter and spring is related to land use, hydrogeology, and other natural or human influences in contributing watersheds.

  15. A validation study of a rapid field-based rating system for discriminating among flow permanence classes of headwater streams in South Carolina

    EPA Science Inventory

    Rapid field-based protocols for classifying flow permanence of headwater streams are needed to inform timely regulatory decisions. Such an existing method was developed for and has been used in North Carolina since 1997. The method uses ordinal scoring of 26 geomorphology, hydr...

  16. Effects of exposure to agricultural drainage ditch water on survivorship, distribution, and abundnance of riffle beetles (Coleoptera: Elmidae) in headwater streams of the Cedar Creek watershed, Indiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riffle Beetles (Coleoptera: Elmidae) require very good water quality, mature streams with riffle habitat, and high dissolved oxygen content. As such, they prove to be good indicators of ecological health in agricultural headwater streams. We conducted static renewal aquatic bioassays using water fro...

  17. Influence of Land Use on the Stable Carbon Isotopic Composition and Concentration of Dissolved Organic Carbon and Dissolved Inorganic Carbon in Georgia Piedmont Headwater Streams

    EPA Science Inventory

    Headwater streams are the dominant land-water interface across much of the landscape and provide many important ecological services. Cycling and transport of various carbon fractions, which serve as important food sources for downstream aquatic ecosystems, are among the important...

  18. Using a Temperature Model and GIS Analysis of Landscape Features to Assess Headwater Resilience to Climate Change in the Driftless Area of Wisconsin

    NASA Astrophysics Data System (ADS)

    Schuster, Z.; Potter, K. W.

    2015-12-01

    Cold groundwater discharges in the headwaters of streams in the Driftless Area of Wisconsin help support cold-water fisheries that are valued by anglers throughout the Midwestern U.S. With climate change expected to increase temperatures and threaten the cold-water habitat of species such as brook and brown trout, the Wisconsin Department of Natural Resources is focusing resources on restoration as means of adapting to climate change. One of the challenges they face is a lack of site-specific temperature data in the headwaters streams that they are targeting for restoration activities. Previous work has shown that there is a strong relationship between air and stream temperature. In this study, we calculated weekly mean air-stream temperature relationships for Driftless region headwaters streams and used air temperature projections from a set of statistically-downscaled GCM models to model thermal metrics relevant to fish species suitability described by Lyons et al. (2009) for historical (1961-2000) and future (2046-2065) conditions. We then combined the stream temperature projections with a GIS analysis of physiographic and geologic features to attempt to develop a way of predicting ungaged headwaters streams in the region that are likely to be resilient to temperature increases due to climate change.

  19. Effects of Land Use on Stable Carbon Isotopic Composition and Concentration of Dissolved Organic Carbon (DOC) and Dissolved Inorganic Carbon (DIC) in Southeastern US Piedmont Headwater Streams

    EPA Science Inventory

    Stable carbon isotopic composition (delta 13C) and concentrations of DOC and DIC were measured in stream water samples collected monthly in 15 headwater streams from an area with extensive poultry and cattle production and a rapidly growing human population. Linear regression te...

  20. Climate change and forest disturbance effect on runoff response in montane basin. Case study - Vydra basin, Sumava Mountains

    NASA Astrophysics Data System (ADS)

    Langhammer, Jakub; Su, Ye; Kaiglová, Jana

    2014-05-01

    Climate change, along with the changes in land use, is one of the key factors driving the changes in hydrological regimes and runoff response in basins. In montane regions, the long-term, as well as abrupt changes may result in significant shifts in runoff regime, especially in relation to extreme runoff events. This study aims to discuss the effect of two key driving forces - climate change and extensive forest disturbance in montane mid-latitude environment. The study area of the Vydra basin is located in the headwater regions of the Sumava Mountains at the border between the Czech Republic and Germany, Central Europe. The study area has undergone an Increase in yearly temperature and extensive forest disturbance resulting from windstorms, consequent bark beetle outbreak and clear-cutting for forest management simultaneously. Various data sources were used for the analyses in this study. The global climate model CM2 was used for reanalysis of historical time series of temperatures since 1871. Selected climate change scenarios of the same model were used for identifying the prospective changes in trends and seasonality of climate parameters. Statistical techniques based on measured data from both spatial and temporal resolutions in the study area were used to detect the co-relationship between hydrologic and meteorological variables for testing the homogeneity of data and identifying the points of change. Furthermore, the daily discharge and precipitation monitored by CHMI at the outlet of the basin were used to analyze various aspects of runoff change. There was an assessed rainfall-runoff relation, runoff variability, changes in seasonal runoff distribution and changes in frequency and seasonality of peak flows. The identified extent and timing of changes are notable and they can be attributed to the cumulative effects of two key driving forces: climate change and forest disturbance, both affecting runoff in the study area. The impact of the two drivers on

  1. Interpreting the suspended sediment dynamics in a mesoscale river basin of Central Mexico using a nested watershed approach

    NASA Astrophysics Data System (ADS)

    Duvert, C.; Némery, J.; Gratiot, N.; Prat, C.; Collet, L.; Esteves, M.

    2009-12-01

    The Cointzio river basin is located within the Mexican Transvolcanic Belt, in the Michoacán state. Land-use changes undergone over last decades lead to significant erosion processes, though affecting limited areas of the basin. Apart from generating a minor depletion of arable land by incising small headwater areas, this important sediment delivery contributed to siltation in the reservoir of Cointzio, situated right downstream of the basin. During 2009 rainy season, a detailed monitoring of water and sediment fluxes was undertaken in three headwater catchments located within the Cointzio basin (Huertitas, Potrerillos and La Cortina, respectively 2.5, 9.3 and 12.0 km2), as well as at the outlet of the main river basin (station of Santiago Undameo, 627 km2). Preliminary tests realized in 2008 underlined the necessity of carrying out a high-frequency monitoring strategy to assess the sediment dynamics in the basins of this region. In each site, water discharge time-series were obtained from continuous water-level measurements (5-min time-step), and stage-discharge rating curves. At the river basin outlet, Suspended Sediment Concentration (SSC) was estimated every 10 minutes through turbidity measurements calibrated with data from automatic sampling. In the three sub-catchments, SSC time-series were calculated using stage-triggered automatic water samplers. The three upland areas monitored in our study present distinct landforms, morphology and soil types. La Cortina is underlain by andisols, rich in organic matter and with an excellent microstructure under wet conditions. Huertitas and Potrerillos both present a severely gullied landscape, bare and highly susceptible to water erosion in degraded areas. As a result, suspended sediment yields in 2009 were expectedly much higher in these two sub-catchments (≈320 t.km-2 in Huertitas and ≈270 t.km-2 in Potrerillos) than in La Cortina (≈40 t.km-2). The total suspended sediment export was approximately of 30 t.km-2

  2. Surface-water hydrology and runoff simulations for three basins in Pierce County, Washington

    USGS Publications Warehouse

    Mastin, M.C.

    1996-01-01

    Creek Basin model and the Clear-Clarks Basin model-by incorporating the generalizations of the conceptual model into the construction of two HSPF numerical models. Initially, the process-related parameters for runoff from glacial-till hillslopes were calibrated with numerical models for three catchment sites and one headwater basin where streamflows were continuously measured and little or no influence from ground water, channel storage, or channel losses affected runoff. At one of the catchments soil moisture was monitored and compared with simulated soil moisture. The values for these parameters were used in the basin models. Basin models were calibrated to the first year of observed streamflow data by adjusting other parameters in the numerical model that simulated channel losses, simulated channel storage in a few of the reaches in the headwaters and in the floodplain of the main stem of Clover Creek, and simulated volume and outflow of the ground-water reservoir representing the regional ground-water aquifers. The models were run for a second year without any adjustments, and simulated results were compared with observed results as a measure of validation of the models. The investigation showed the importance of defining the ground-water flow boundaries and demonstrated a simple method of simulating the influence of the regional ground-water aquifer on streamflows. In the Clover Creek Basin model, ground-water flow boundaries were used to define subbasins containing mostly glacial outwash soils and not containing any surface drainage channels. In the Clear-Clarks Basin model, ground-water flow boundaries outlined a recharge area outside the surface-water boundaries of the basin that was incorporated into the model in order to provide sufficient water to balance simulated ground-water outflows to the creeks. A simulated ground-water reservoir used to represent regional ground-water flow processes successfully provided the proper water balance of inflows and outfl

  3. Nutrient, Habitat, and Basin-Characteristics Data and Relations with Fish and Invertebrate Communities in Indiana Streams, 1998-2000

    USGS Publications Warehouse

    Frey, Jeffrey W.; Caskey, Brian J.

    2007-01-01

    An analysis of existing nutrient, habitat, basin-characteristics, and biological-community (fish and invertebrate) data assessed significant relations between nutrients and biological data. Data from 1998 through 2000 for 58 sites in the Upper Wabash River Basin, Lower Wabash River Basin, and tributaries to the Great Lakes and Ohio River Basins were analyzed. Correspondence analysis was used to assess significant relations among nutrients, habitat, basin-characteristics, and biological-community data. Canonical correspondence analysis was used to identify which environmental parameters most influenced the biological communities. When all 58 sites were assessed, six biological-community attributes, metric scores, or site scores were statistically sigificant but weak. When a subset of data was analyzed for eight headwater streams in one ecoregion to minimize the naturally occurring variability associated with the 58 sites, the strength of the relations increased and 24 attributes, metric scores, or site scores were significantly related. Fish-community composition in the 58 sites was most influenced by habitat and land use but not by nutrients. The invertebrate-community composition in the 58 sites was most influenced by habitat, land use, soils, and one nutrient (total Kjeldahl nitrogen [TKN]).

  4. Simulation of daily streamflow for nine river basins in eastern Iowa using the Precipitation-Runoff Modeling System

    USGS Publications Warehouse

    Haj, Adel E.; Christiansen, Daniel E.; Hutchinson, Kasey J.

    2015-10-14

    The accuracy of Precipitation-Runoff Modeling System model streamflow estimates of nine river basins in eastern Iowa as compared to measured values at U.S. Geological Survey streamflow-gaging stations varied. The Precipitation-Runoff Modeling System models of nine river basins in eastern Iowa were satisfactory at estimating daily streamflow at 57 of the 79 calibration sites and 13 of the 14 validation sites based on statistical results. Unsatisfactory performance can be contributed to several factors: (1) low flow, no flow, and flashy flow conditions in headwater subbasins having a small drainage area; (2) poor representation of the groundwater and storage components of flow within a basin; (3) lack of accounting for basin withdrawals and water use; and (4) the availability and accuracy of meteorological input data. The Precipitation- Runoff Modeling System models of nine river basins in eastern Iowa will provide water-resource managers with a consistent and documented method for estimating streamflow at ungaged sites and aid in environmental studies, hydraulic design, water management, and water-quality projects.

  5. Response of sap flow to environmental factors in the headwater catchment of Miyun Reservoir in subhumid North China

    NASA Astrophysics Data System (ADS)

    Tie, Qiang; Hu, Hongchang; Tian, Fuqiang; Liu, Yaping; Xu, Ran

    2015-04-01

    Since the headwater catchment of Miyun Reservoir is the main drinking water conservation area of Beijing, its water cycle is of importance for the regional water resource. Transpiration is an important component of water cycle, which can be estimated by sap flow. In this study, the dynamics of sap flow and its response to environmental factors and relationship with leaf area index (LAI) were analyzed. The field study was conducted in the Xitaizi Experimental Catchment, located in the headwater catchment of Miyun Reservoir in subhumid North China. The Aspen (Populus davidiana) and Epinette (Larix gmelinii) are the two dominant tree species. Sap flow in 15 Aspen (Populus davidiana) trees was monitored using thermal dissipation probes (TDP) during the growing season of 2013 and 2014, and sap flow in another 3 Epinette (Larix gmelinii) trees was also monitored during September and October in 2014 for comparative analysis. Physiological and biometric parameters of the selected trees and the environmental factors, including meteorological variables, soil moisture content and groundwater table depth were measured. Vapor pressure deficit (VPD), variable of transpiration (VT) and reference crop evapotranspiration (ET0) were calculated using the measured environmental factors. The LAI, which is used to characterize phenophase, was calculated using the Moderate Resolution Imaging Spectroradiometer (MODIS) LAI product (MCD15A3). Correlation analysis for daily sap flow and air temperature, relative humidity, precipitation, wind speed, solar radiation, VPD, VT and ET0 under different soil moisture and groundwater table depth conditions was performed. Diurnal course and hysteresis of sap flow were analyzed as a function of air temperature, solar radiation, VPD and VT on the typical sunny, cloudy and rainy days under different soil moisture conditions. Correlation analysis between daily sap flow and LAI showed that LAI and phenophase significantly influence sap flow and restrict

  6. Faunal assemblages and multi-scale habitat patterns in headwater tributaries of the South Fork Trinity River - an unregulated river embedded within a multiple-use landscape

    USGS Publications Warehouse

    Welsh, H.H.; Hodgson, G.R.; Duda, J.J.; Emlen, J.M.

    2010-01-01

    Headwaters can represent 80% of stream kilometers in a watershed, and they also have unique physical and biological properties that have only recently been recognized for their importance in sustaining healthy functioning stream networks and their ecological services. We sampled 60 headwater tributaries in the South Fork Trinity River, a 2,430 km2, mostly forested, multiple-use watershed in northwestern California. Our objectives were: (1) to differentiate unique headwater types using 69 abiotic and vegetation variables measured at three spatial scales, and then to reduce these to informative subsets; (2) determine if distinct biota occupied the different tributary types; (3) determine the environmental attributes associated with the presence and abundance of these biotic assemblages; and (4) using niche modeling, determine key attribute thresholds to illustrate how these biota could be employed as metrics of system integrity and ecological services. Several taxa were sufficiently abundant and widespread to use as bio-indicators: the presence and abundance of steelhead trout (Oncorhynchus mykiss), herpetofauna (reptile and amphibian) species richness, and signal crayfish (Pacifastacus leniusculus) represented different trophic positions, value as commercial resources (steelhead), sensitivity to environmental stress (amphibians), and indicators of biodiversity (herpetofauna species richness). Herpetofauna species richness did not differ, but abundances of steelhead trout, signal crayfish, and amphibian richness all differed significantly among tributary types. Niche models indicated that distribution and abundance patterns in both riparian and aquatic environments were associated with physical and structural attributes at multiple spatial scales, both within and around reaches. The bio-indicators responded to unique sets of attributes, reflecting the high environmental heterogeneity in headwater tributaries across this large watershed. These niche attributes

  7. Origin of cratonic basins

    NASA Astrophysics Data System (ADS)

    Dev. Klein, George; Hsui, Albert T.

    1987-12-01

    Tectonic subsidence curves show that the Illinois, Michigan, and Williston basins formed by initial fault-controlled mechanical subsidence during rifting and by subsequent thermal subsidence. Thermal subsidence began around 525 Ma in the Illinois Basin, 520 460 Ma in the Michigan Basin, and 530 500 Ma in the Williston Basin. In the Illinois Basin, a second subsidence episode (middle Mississippian through Early Permian) was caused by flexural foreland subsidence in response to the Alleghanian-Hercynian orogeny. Resurgent Permian rifting in the Illinois Basin is inferred because of intrusion of well-dated Permian alnoites; such intrusive rocks are normally associated with rifting processes. The process of formation of these cratonic basins remains controversial. Past workers have suggested mantle phase changes at the base of the crust, mechanical subsidence in response to isostatically uncompensated excess mass following igneous intrusions, intrusion of mantle plumes into the crust, or regional thermal metamorphic events as causes of basin initiation. Cratonic basins of North America, Europe, Africa, and South America share common ages of formation (around 550 to 500 Ma), histories of sediment accumulation, temporal volume changes of sediment fills, and common dates of interregional unconformities. Their common date of formation suggests initiation of cratonic basins in response to breakup of a late Precambrian super-continent. This supercontinent acted as a heat lens that caused partial melting of the lower crust and upper mantle followed by emplacement of anorogenic granites during extensional tectonics in response to supercontinent breakup. Intrusion of anorogenic granites and other partially melted intrusive rocks weakened continental lithosphere, thus providing a zone of localized regional stretching and permitting formation of cratonic basins almost simultaneously over sites of intrusion of these anorogenic granites and other partially melted intrusive rocks.

  8. Hydrological modelling of an artificial headwater catchment using the model system WaSiM-ETH

    NASA Astrophysics Data System (ADS)

    Hölzel, H.; Diekkrüger, B.

    2009-04-01

    The hydrological headwater catchment Chicken Creek (6.5 ha) was constructed in a lignite open-cast mine by Cottbus (Germany) to study initial processes of ecosystem development. The catchment has been intensively monitored for more than three years. Thereby, it is well suited to test and develop hydrological models. The construction of a clay layer in the basement simplifies the balancing of the water cycle since lateral inflows and vertical outflows can be neglected. For modelling purposes all basic input data were given, but neither discharge nor soil moisture measurements were provided. Hence, no high model quality can be feigned by fitting simulated results on observed output data. To compare the ability of different models and modellers to describe the hydrological behaviour of that catchment, a model competition was declared, on which several international scientists take part, all specialised in hydrological modelling. The contest is conducted in different levels, whereupon the knowledge of modellers concerning the investigated catchment will be increased stepwise. All modellers use the same database and results will be evaluated by an independent observer group. Thereby, the comparability between different model applications is guaranteed. We applied the process-based distributed Water balance Simulation Model (WaSiM-ETH) by Schulla & Jasper (2007) to simulate the first three years since the catchment construction was finished (Sep. 2005 - Aug. 2008). For the first modelling exercise important initial conditions (e.g. soil moisture) were unknown. Due to the lack of field experiences, effects of a constructed lake were disregarded. Therefore, the results of the first level were far away from being perfect, e.g. discharge was simulated from the beginning which was not observed because in reality soil water and lake storages were filled up first. The biggest differences occurred between simulated and observed surface runoff. In reality, surface runoff is the

  9. Spatial and temporal water quality dynamics during baseflow in an agricultural headwater catchment

    NASA Astrophysics Data System (ADS)

    Schuetz, Tobias; Weiler, Markus; Saroos, Manuel

    2013-04-01

    Understanding the interaction of time variant source areas and biogeochemical in-stream processes and the determination of resulting spatial and temporal signatures of stream water composition will improve the prediction and management of water quality at the catchment scale. During baseflow periods runoff source areas can change over time depending e.g. on storage depletion rates, actual wetness, groundwater level or local evapotranspiration rates. Due to the resulting space/time variant water fluxes, these effects are also expressed in the physico-chemical composition of surface waters. Unfortunately the resulting signature is often overlain by biogeochemical in-stream processes, which make it difficult to identify physico-chemical signatures of specific runoff source areas. We studied these interactions in a 1.7 km² agricultural headwater catchment. A dense artificial drainage network and a predominantly impervious streambed allowed for detecting distinct locations of groundwater inflow and determining ongoing biogeochemical in-stream processes. The analysis of sub-catchment storage depletion and resulting time variant quantitative and qualitative impacts on stream water composition was based on observations made during 11 catchment wide synoptic sampling campaigns during the summer baseflow period. We measured stream discharges with salt dilution gauging as well as water temperatures (T) and electrical conductivity (EC) upstream, downstream and inside all active drain pipes. During two campaigns we took additional water samples for major ion analysis at all sampling points. Discharges, T and EC stream-network data sets were used to spatially determine groundwater contributions using mixing equations for 2 and 3 components, respectively. Thereby we derived local baseflow recessions in relation to the catchment wide stream discharge. Using a water balance approach we determined active runoff source areas for each drain pipe and identified the dominant land use

  10. Origin of particulate organic matter exported during storm events in a forested headwater catchment.

    NASA Astrophysics Data System (ADS)

    Jeanneau, Laurent; Rowland, Richard D.; Inamdar, Shreeram P.

    2016-04-01

    and river banks decreases while the influence of Forest O horizon increases. For suspended sediments, the evolution during storm events were opposite in the 12ha and the 79ha catchments. In the 12ha catchment, during the rising limb of the hydrograph, POM seems to be inherited from stream bed sediments and river banks, while from the rising limb to the peak flow, the influence of litter and/or wetland increases. This influence decreases during the falling limb. The opposite trend was observed in the 79ha catchment, with an increasing contribution of stream bed sediments to the OM exported during a storm event. What is the information to take away? First POM transferred in headwater catchments has multiple sources. Secondly, the combination of those sources is different along the size continuum of particles. Then, down a continuum of catchment drainage locations, the combination of sources changes both along the size continuum and during storm events. This information is critical for identifying the various drivers and mechanisms behind POM transport and for understanding the impacts of POM on aquatic metabolism and downstream water quality.

  11. Examining the effects of forest thinning on hydrological processes at different catchment scales in forested headwater

    NASA Astrophysics Data System (ADS)

    Dung, Bui Xuan; Gomi, Takashi; Onda, Yuichi; Kato, Hiroaki; Hiraoka, Marino

    2013-04-01

    We conducted field observation in nested headwater catchments draining Japanese cypress (Chamaecyparis obtusa) and cedar (Cryptomeria japonica) forests at Tochigi prefecture for examining the effects of forest thinning on hydrological processes at different catchment scales. 50% of the stems was removed with line thinning in catchment K2 (treatment catchment), while catchment K3 remained untreated as a control. We monitored nested catchment within K2-1 (17.1 ha) as K2-2 (10.2 ha), K2-3 (3.7 ha) and K2-4 (5.1 ha), and within K3-1 (8.9 ha) as K3-2 (3.0 ha). Runoff from the catchments was monitored during the pre-thinning (from April, 2010 to May 2011), and the post-thinning periods (from June 2011 to December 2012). Paired-catchment and hydrograph separation analysis were used to evaluate the effects of forest thinning on hydrological processes at different catchment scales. We developed the pre-thinning calibration equation for predicting post-thinning behaviors. Paired catchment analysis revealed that annual catchment runoff increased 648 mm in K2-1, 414 mm in K2-2, 528 mm in K2-3, and 566 mm in K2-4 during the post-thinning period. Greater increase of flow in largest catchment (K2-1) was be due to the contribution of increased delayed flow from infiltrated water, reappearing as surface flow (i.e., quick flow) in the lower parts of the catchment, caused by harvested activities (logging, road, skid trail). Because both quick and delayed flows increased significantly in the larger catchments of K2-1 and K2-2, while only delayed flow of smaller catchments (K2-3 and K2-4) increased significantly during the post-thinning period. Delayed flow also increased greater in K2-3 and K2-4, smaller in K2-2 but greatest in K2-1. Moreover, the increasing contributions to runoff from deeper groundwater sources that are recharged in upslope subcatchments caused increase amount of flow. This was explained when increase of annual base flow (i.e., bedrock flow) of zero-order catchments

  12. Dissolved Carbon Flux and Mass Balance From a Wetland-Dominated Karstic Headwater Catchment

    NASA Astrophysics Data System (ADS)

    Duval, T. P.; Waddington, J. M.; Branfireun, B. A.

    2009-05-01

    The stream-borne dissolved carbon efflux of peatland-draining catchments is dominated by organic carbon, whereas inorganic carbon dominates the flux from calcareous bedrock catchments. The export of dissolved carbon from calcareous bedrock catchments with significant wetland coverage has not previously been determined. This study documents the spatiotemporal variability of dissolved carbon (inorganic + organic) along a headwater stream in southern Ontario, Canada, as it drains three distinct wetland types: a calcareous fen, a riparian cedar swamp, and a cattail marsh. Upon emergence from the groundwater seeps, the spring water contained 28 times more CO2 than in equilibrium with the atmosphere. This supersaturation decreased to just 5 times equilbrium as the stream leaves the catchment through the marsh, representing a decrease in CO2 concentration of 11 mg L-1, lost to the atmosphere as exsolution. The groundwater seeps contained an average of 1.25±0.75 mg L-1 of dissolved organic carbon (DOC) from May to November 2007, one of the driest years on record in the region. At the catchment outlet through the marsh, DOC concentrations were slightly higher and more variable during the same period at 2.27±1.29 mg L-1, as a fall flushing event resulted in concentrations > 7 mg L-1. This DOC concentration is small compared to the 58.72±3.9 mg L-1 of dissolved inorganic carbon (DIC, as bicarbonate ion) contained within the water leaving the catchment. At 0.21 and 0.17 g m-2 d-1 from May-July and August-November 2007, respectively, the DIC dominated the carbon flux out of the watershed, compared with 0.007 and 0.008 g m- 2 d-1 DOC and 0.015 and 0.009 g m-2 d-1 CO2 exsolution during the same period. Results of the 2007 season will be contrasted to the 2008 season, one of the wettest on record. The watershed is underlain by Silurian dolomite that exhibits karst fractures, resulting in a complex subsurface hydrogeology that influences carbon transport and mass balances

  13. Hydro-climatic control of stream dissolved organic carbon in headwater catchment

    NASA Astrophysics Data System (ADS)

    Humbert, Guillaume; Jaffrezic, Anne; Fovet, Ophélie; Gruau, Gérard; Durand, Patrick

    2014-05-01

    Dissolved organic matter (DOM) is a key form of the organic matter linking together the water and the carbon cycles and interconnecting the biosphere (terrestrial and marine) and the soil. At the landscape scale, land use and hydrology are the main factors controlling the amount of DOM transferred from soils to the stream. In an intensively cultivated catchment, a recent work using isotopic composition of DOM as a marker has identified two different sources of DOM. The uppermost soil horizons of the riparian wetland appear as a quasi-infinite source while the topsoil of the hillslope forms a limited one mobilized by water-table rise and exported to the stream across the upland-riparian wetland-stream continuum. In addition to the exportation of DOM via water fluxes, climatic factors like temperature and precipitation regulate the DOM production by influencing microbial activity and soil organic matter degradation. The small headwater catchment (5 km²) of Kervidy-Naizin located in Brittany is part of the Environment Research Observatory (ORE) AgrHys. Weather and the hydro-chemistry of the stream, and the groundwater levels are daily recorded since 1993, 2000 and 2001 respectively. Over 13 contrasted hydrological years, the annual flow weighted mean concentration of dissolved organic carbon (DOC) is 5.6 mg.L-1 (sd = 0.7) for annual precipitation varying from 488mm to 1327mm and annual mean temperatures of 11°C (sd = 0.6). Based on this considerable dataset and this annual variability, we tried to understand how the hydro-climatic conditions determinate the stream DOC concentrations along the year. From the fluctuations of water table depth, each hydrologic year has been divided into three main period: i) progressive rewetting of the riparian wetland soils, ii) rising and holding high of the water table in the hillslope, iii) drawdown of the water-table, with less and less topsoil connected to the stream. Within each period base flow and storm flow data were first

  14. Evaluation of agricultural best-management practices in the Conestoga River headwaters, Pennsylvania; description and water quality of the Little Conestoga Creek headwaters prior to the implementation of nutrient management

    USGS Publications Warehouse

    Fishel, D.K.; Brown, M.J.; Kostelnik, K.M.; Howse, M.A.

    1992-01-01

    The headwaters of the Conestoga River are being studied to determine the effects of agricultural Best-Management Practices on surface-water and ground-water quality. As part of this study, a 5.82-square-mile area of the Little Conestoga Creek headwaters (Small Watershed) was monitored during 1984-86, prior to implementation of Best-Management Practices. This report describes the land use and hydrology of this study area and characterizes its surface-water and ground-water quality during the pre-Best-Management Practice phase. During base-flow conditions, median concentrations of dissolved nitrite plus nitrate nitrogen as nitrogen increased from 2.7 to 8.1 milligrams per liter as the stream flowed through the intensively-farmed carbonate valley. Median total phosphorus increased from 0.05 to 0.20 milligram per liter. Concentrations of dissolved nitrate nitrogen as nitrogen measured in ground water in carbonate rocks in the valley were as great as 25 milligrams per liter and consistently exceeded 10 milligrams per liter. Statistical analysis showed that it will require substantial reductions in concentrations and discharges of nitrogen and phosphorus in base flow to obtain statistically measurable improvements in water quality. If concentrations and discharges of total nitrogen in base flow at the five sites are reduced by 15 to 33 percent, and by 63 to 70 percent, respectively, then the Wilcoxon Mann-Whitney rank-sum test will be able to detect an improvement in water quality 95 percent of the time. Likewise, if concentrations of total phosphorus are reduced by 36 to 54 percent, or discharges of total phosphorus are reduced by 52 to 69 percent at the five sites, then an improvement in water quality will be able to be detected 95 percent of the time.

  15. Impacts of a Rapidly Declining Mountain Snowpack on Streamflow Timing in Canada's Fraser River Basin.

    PubMed

    Kang, Do Hyuk; Gao, Huilin; Shi, Xiaogang; Islam, Siraj Ul; Déry, Stephen J

    2016-01-27

    With its headwaters in the water towers of the western Cordillera of North America, the Fraser River is one of the continent's mightiest rivers by annual flows, supplies vital freshwater resources to populous downstream locations, and sustains the world's largest stocks of sockeye salmon along with four other salmon species. Here we show the Variable Infiltration Capacity (VIC) model's ability to reproduce accurately observed trends in daily streamflow for the Fraser River's main stem and six of its major tributaries over 1949-2006 when air temperatures rose by 1.4 °C while annual precipitation amounts remained stable. Rapidly declining mountain snowpacks and earlier melt onsets result in a 10-day advance of the Fraser River's spring freshet with subsequent reductions in summer flows when up-river salmon migrations occur. Identification of the sub-basins driving the Fraser River's most significant changes provides a measure of seasonal predictability of future floods or droughts in a changing climate.

  16. Hydrologic studies of small watersheds, Honey Creek basin, Collin and Grayson Counties, Texas, 1953-1959

    USGS Publications Warehouse

    Gilbert, Clarence R.; Commons, G.G.; Koberg, G.E.; Kennon, F.W.

    1964-01-01

    The effect on the flood regimen at a downstream point because of floodwaterretarding structures in the headwaters will vary with the amount and intensity of the precipitation and with antecedent conditions. The beneficial effects of the structures on Honey Creek during the floods of April and May 1957 is illustrative. During the period April 19 to May 31, 1957, the total volume of inflow to the floodwater-retarding structures was equivalent to 4.3 times the combined capacities of the pools from an average basin rainfall of 30.31 inches. The retarding effects of the structures limited the flooding on Honey Creek at the gage to minor flooding on only five occasions during that period.

  17. Projected hydrologic changes in monsoon-dominated Himalaya Mountain basins with changing climate and deforestation

    NASA Astrophysics Data System (ADS)

    Neupane, Ram P.; White, Joseph D.; Alexander, Sara E.

    2015-06-01

    In mountain headwaters, climate and land use changes affect short and long term site water budgets with resultant impacts on landslide risk, hydropower generation, and sustainable agriculture. To project hydrologic change associated with climate and land use changes in the Himalaya Mountains, we used the Soil and Water Assessment Tool (SWAT) calibrated for the Tamor and Seti River basins located at eastern and western margins of Nepal. Future climate change was modeled using averaged temperature and precipitation for 2080 derived from Special Report on Emission Scenarios (SRES) (B1, A1B and A2) of 16 global circulation models (GCMs). Land use change was modeled spatially and included expansion of (1) agricultural land, (2) grassland, and (3) human settlement area that were produced by considering existing land use with projected changes associated with viability of elevation and slope characteristics of the basins capable of supporting different land use type. From these simulations, higher annual stream discharge was found for all GCM-derived scenarios compared to a baseline simulation with maximum increases of 13 and 8% in SRES-A2 and SRES-A1B for the Tamor and Seti basins, respectively. On seasonal basis, we assessed higher precipitation during monsoon season in all scenarios that corresponded with higher stream discharge of 72 and 68% for Tamor and Seti basins, respectively. This effect appears to be geographically important with higher influence in the eastern Tamor basin potentially due to longer and stronger monsoonal period of that region. However, we projected minimal changes in stream discharge for the land use scenarios potentially due to higher water transmission to groundwater reservoirs associated with fractures of the Himalaya Mountains rather than changes in surface runoff. However, when combined the effects of climate and land use changes, discharge was moderately increased indicating counteracting mechanisms of hydrologic yield in these mountains

  18. Long-term effects on nitrogen and benthic fauna of extreme weather events: Examples from two Swedish headwater streams.

    PubMed

    Löfgren, Stefan; Grandin, Ulf; Stendera, Sonja

    2014-01-01

    Climate change is expected to cause an increased frequency of extreme events such as heavy floods and major storms. Such stochastic events have an immediate impact on surface water quality, but the long-term effects are largely unknown. In this study, we assess long-term monitoring data from two Swedish headwater catchments affected by extreme weather events. At one site, where nitrogen effects in soil water, groundwater, and stream water were studied after storm-felling and subsequent forest dieback from bark beetle attack, long-term (> 5 years) but relatively modest (generally <1 mg L⁻¹) increases in ammonium (NH(4)-N) and nitrate (NO(3)-N) concentrations were observed in the various aqueous media. At the other site, where effects on benthic fauna were studied in a stream impacted by extreme geophysical disturbances caused by rainstorm-induced flashflood, only short-term (1 year) effects were revealed both regarding diversity and composition of species.

  19. Ontogenetic and diel variation in stream habitat use by brook trout (Salvelinus fontinalis) in a headwater stream

    USGS Publications Warehouse

    Johnson, J.H.; Ross, R.M.; Dropkin, D.S.; Redell, L.A.

    2011-01-01

    Although considerable information exists on habitat use by stream salmonids, only a small portion has quantitatively examined diurnal and nocturnal habitat variation. We examined diel variation in habitat use by age-0 and age-1+ brook trout (Salvelinus fontinalis) during summer and autumn in a headwater stream in northern Pennsylvania. Habitat variables measured included cover, depth, substrate, and velocity. The most pronounced diel variation occurred in the use of cover during both seasons. Both age-0 brook trout and age-1+ trout were associated with less cover at night. Age-0 brook trout occupied swifter water during the day than at night during both seasons, but the difference was not significant. Increased cover, depth, and substrate size governed the habitat of age-1+ brook trout. Our findings support the need for a better understanding of diel differences in habitat use of stream salmonids when considering habitat enhancement and protection.

  20. Assessment of climate change and increased atmospheric CO2 impacts on water quality in an intensive agricultural headwater catchment

    NASA Astrophysics Data System (ADS)

    Salmon-Monviola, Jordy; Moreau, Pierre; Benhamou, Cyril; Durand, Patrick; Merot, Philippe; Oehler, François; Gascuel-Odoux, Chantal

    2013-04-01

    Climate change and increasing atmospheric CO2 concentration can lead to disturbances in the global hydrological and nitrogen (N) cycling, and losses in catchment systems. Potential impacts on water and N cycling have been studied in large catchments with a variety of land uses but less attention has focused on agricultural headwater catchments. Despite their relatively small dimensions, headwater catchments of 1-10 km² play a dominant role in N transformations in the landscape, and streams in such catchments may have major impacts on downstream water quantity and quality. This issue is particular important for agricultural catchment which have to reach the WFD targets, where land use changes has to be analysed in combination with climate change. The effects of climate change and rising concentrations of atmospheric CO2 have been studied on (1) changes in hydrological and N balance components on a yearly basis and (2) the seasonal dynamics of water and N fluxes. The spatially distributed agro-hydrological model TNT2 (Topography-based nitrogen Transfers and Transformations) driven by ARPEGE (Action de Recherche Petite Echelle Grande Echelle) climate-model outputs from A1B scenario have been applied on the Kervidy-Naizin headwater catchment (western France), a long term hydrological observatory. Consideration of atmospheric CO2 concentration was implemented at two levels in TNT2: i) to account for the CO2 effect on stomatal conductance TNT2; ii) to consider effect of CO2 on biomass growth. Climate data from ARPEGE model, corrected with the quantile-quantile bias correction method, over 30-year simulation periods were used as TNT2 input (Salmon-Monviola et al., in review). With increased CO2, the main trends in water balance were a significant decrease in annual actual evapotranspiration, a moderate decrease in annual discharge and wetland extent, and a decrease in spring and summer of groundwater recharge and soil water content. Not considering the effects of

  1. K Basin safety analysis

    SciTech Connect

    Porten, D.R.; Crowe, R.D.

    1994-12-16

    The purpose of this accident safety analysis is to document in detail, analyses whose results were reported in summary form in the K Basins Safety Analysis Report WHC-SD-SNF-SAR-001. The safety analysis addressed the potential for release of radioactive and non-radioactive hazardous material located in the K Basins and their supporting facilities. The safety analysis covers the hazards associated with normal K Basin fuel storage and handling operations, fuel encapsulation, sludge encapsulation, and canister clean-up and disposal. After a review of the Criticality Safety Evaluation of the K Basin activities, the following postulated events were evaluated: Crane failure and casks dropped into loadout pit; Design basis earthquake; Hypothetical loss of basin water accident analysis; Combustion of uranium fuel following dryout; Crane failure and cask dropped onto floor of transfer area; Spent ion exchange shipment for burial; Hydrogen deflagration in ion exchange modules and filters; Release of Chlorine; Power availability and reliability; and Ashfall.

  2. Hyporheic transport in headwater mountain streams is time-invariant in locations where geologic controls dominate hydrologic forcin

    NASA Astrophysics Data System (ADS)

    Ward, A. S.; Schmadel, N.; Wondzell, S. M.; Harman, C. J.; Gooseff, M. N.; Singha, K.

    2015-12-01

    Transport along riparian and hyporheic flowpaths is generally believed to integrate the responses of streams and aquifers to dynamic hydrological forcing. Although it is generally expected transport along these flow paths is time-variable, such dynamic responses have seldom been demonstrated. Further, we do not understand how hydrological forcing interacts with local geologic setting (i.e., valley and streambed morphology) We conducted a series of four stream solute tracer injections in each of two watersheds with contrasting valley morphology in the H.J. Andrews Experimental Forest, monitoring tracer concentrations in the stream and in a network of shallow wells in each watershed. Time series analyses were used to deconvolve transport along subsurface flowpaths from transport in the stream channel. We found time-invariant hyporheic transport in the narrow, bedrock-constrained valley and near large roughness elements (e.g., steps, logs) in the wider valley bottom despite order of magnitude changes in discharge, suggesting geologic controls dominate hyporheic transport in these locations. In contrast, we observed increases in mean arrival time and temporal variance with decreasing discharge at the riparian-hillslope transition, suggesting hydrological dynamics control transport in these locations. We pose several mechanisms by which dynamic hydrology and geologic setting interact that may explain the observed behavior. We interpret time-invariant transport as an indication that discharge in the surface stream is a poor predictor of exchange along the stream-hyporheic-riparian-hillslope continuum in headwater valleys. As such, models able to account for the transition from geologically-dominated processes in the near-stream subsurface to hydrologically-dominated processes near the hillslope are required to predict transport and fate in valley bottoms of headwater mountain streams.

  3. Composition of riparian litter input regulates organic matter decomposition: Implications for headwater stream functioning in a managed forest landscape.

    PubMed

    Lidman, Johan; Jonsson, Micael; Burrows, Ryan M; Bundschuh, Mirco; Sponseller, Ryan A

    2017-02-01

    Although the importance of stream condition for leaf litter decomposition has been extensively studied, little is known about how processing rates change in response to altered riparian vegetation community composition. We investigated patterns of plant litter input and decomposition across 20 boreal headwater streams that varied in proportions of riparian deciduous and coniferous trees. We measured a suite of in-stream physical and chemical characteristics, as well as the amount and type of litter inputs from riparian vegetation, and related these to decomposition rates of native (alder, birch, and spruce) and introduced (lodgepole pine) litter species incubated in coarse- and fine-mesh bags. Total litter inputs ranged more than fivefold among sites and increased with the proportion of deciduous vegetation in the riparian zone. In line with differences in initial litter quality, mean decomposition rate was highest for alder, followed by birch, spruce, and lodgepole pine (12, 55, and 68% lower rates, respectively). Further, these rates were greater in coarse-mesh bags that allow colonization by macroinvertebrates. Variance in decomposition rate among sites for different species was best explained by different sets of environmental conditions, but litter-input composition (i.e., quality) was overall highly important. On average, native litter decomposed faster in sites with higher-quality litter input and (with the exception of spruce) higher concentrations of dissolved nutrients and open canopies. By contrast, lodgepole pine decomposed more rapidly in sites receiving lower-quality litter inputs. Birch litter decomposition rate in coarse-mesh bags was best predicted by the same environmental variables as in fine-mesh bags, with additional positive influences of macroinvertebrate species richness. Hence, to facilitate energy turnover in boreal headwaters, forest management with focus on conifer production should aim at increasing the presence of native deciduous

  4. Headwater Nutrient Concentration Patterns in Response to Storm Events Across Land Use Types using In Situ Sensors

    NASA Astrophysics Data System (ADS)

    Price, A.; Wollheim, W. M.; Mulukutla, G. K.; Carey, R. O.; McDowell, W. H.

    2012-12-01

    Understanding the aquatic biogeochemical impacts of land use change and climate variability will require improved understanding of nutrient variability over temporal scales ranging from storms to seasons. New in situ sensor technology offers the prospect of efficient nutrient measurements over multiple time scales. We quantified nutrient flux patterns in response to storm events across seasons using in situ nutrient sensors deployed in headwater streams draining three land use types (forest, suburban, and agriculture) within the Lamprey River watershed, New Hampshire, between April-December 2012. We utilized two sensor suites, each consisting of a Satlantic Submersible Ultraviolet Nitrate Analyzer (NO3-N), Turner Designs C6 Multi-Sensor Platform (CDOM, Turbidity, Chl), Hydrolab MS5 (Dissolved Oxygen, pH), WET Labs Cycle P (PO4-P), and Hobo Water Level & Conductivity meters. Preliminary spring/summer comparisons at the suburban site suggest increased baseflow nitrate concentrations and decreased diurnal nitrate variability (~0.05 vs. 0.035 mg/L daily fluctuation) following leaf emergence in spring. Nitrate concentrations were diluted during storms. Hysteresis was evident, suggesting groundwater nitrate sources attributable to septic systems were diluted by surface runoff during spring storms. The agricultural stream showed similar but more extreme patterns of increasing baseflow nitrate during the summer (~2.4 to 4.1 mg/L) and dilution during storms. The compilation of a high-frequency dataset for headwater streams across seasons and land-use types will provide valuable insight into complex land use/water quality relationships in urbanizing watersheds.

  5. DIN retention-transport through four hydrologically connected zones in a headwater catchment of the Upper Mississippi River

    USGS Publications Warehouse

    Triska, F.J.; Duff, J.H.; Sheibley, R.W.; Jackman, A.P.; Avanzino, R.J.

    2007-01-01

    Dissolved inorganic nitrogen (DIN) retention-transport through a headwater catchment was synthesized from studies encompassing four distinct hydrologic zones of the Shingobee River Headwaters near the origin of the Mississippi River. The hydrologic zones included: (1) hillslope ground water (ridge to bankside riparian); (2) alluvial riparian ground water; (3) ground water discharged through subchannel sediments (hyporheic zone); and (4) channel surface water. During subsurface hillslope transport through Zone 1, DIN, primarily nitrate, decreased from ???3 mg-N/l to <0.1 mg-N/l. Ambient seasonal nitrate:chloride ratios in hillslope flow paths indicated both dilution and biotic processing caused nitrate loss. Biologically available organic carbon controlled biotic nitrate retention during hillslope transport. In the alluvial riparian zone (Zone 2) biologically available organic carbon controlled nitrate depletion although processing of both ambient and amended nitrate was faster during the summer than winter. In the hyporheic zone (Zone 3) and stream surface water (Zone 4) DIN retention was primarily controlled by temperature. Perfusion core studies using hyporheic sediment indicated sufficient organic carbon in bed sediments to retain ground water DIN via coupled nitrification-denitrification. Numerical simulations of seasonal hyporheic sediment nitrification-denitrification rates from perfusion cores adequately predicted surface water ammonium but not nitrate when compared to 5 years of monthly field data (1989-93). Mass balance studies in stream surface water indicated proportionally higher summer than winter N retention. Watershed DIN retention was effective during summer under the current land use of intermittently grazed pasture. However, more intensive land use such as row crop agriculture would decrease nitrate retention efficiency and increase loads to surface water. Understanding DIN retention capacity throughout the system, including special channel

  6. Water chemistry in 179 randomly selected Swedish headwater streams related to forest production, clear-felling and climate.

    PubMed

    Löfgren, Stefan; Fröberg, Mats; Yu, Jun; Nisell, Jakob; Ranneby, Bo

    2014-12-01

    From a policy perspective, it is important to understand forestry effects on surface waters from a landscape perspective. The EU Water Framework Directive demands remedial actions if not achieving good ecological status. In Sweden, 44 % of the surface water bodies have moderate ecological status or worse. Many of these drain catchments with a mosaic of managed forests. It is important for the forestry sector and water authorities to be able to identify where, in the forested landscape, special precautions are necessary. The aim of this study was to quantify the relations between forestry parameters and headwater stream concentrations of nutrients, organic matter and acid-base chemistry. The results are put into the context of regional climate, sulphur and nitrogen deposition, as well as marine influences. Water chemistry was measured in 179 randomly selected headwater streams from two regions in southwest and central Sweden, corresponding to 10 % of the Swedish land area. Forest status was determined from satellite images and Swedish National Forest Inventory data using the probabilistic classifier method, which was used to model stream water chemistry with Bayesian model averaging. The results indicate that concentrations of e.g. nitrogen, phosphorus and organic matter are related to factors associated with forest production but that it is not forestry per se that causes the excess losses. Instead, factors simultaneously affecting forest production and stream water chemistry, such as climate, extensive soil pools and nitrogen deposition, are the most likely candidates The relationships with clear-felled and wetland areas are likely to be direct effects.

  7. A method to estimate the impact of clear-cutting on nutrient concentrations in boreal headwater streams.

    PubMed

    Palviainen, Marjo; Finér, Leena; Laurén, Ari; Mattsson, Tuija; Högbom, Lars

    2015-10-01

    Large-scale forestry operations, like clear-cutting, may impair surface water quality if not done with environmental considerations in mind. Catchment and country level estimates of nutrient loads from forestry are generally based on specific export values, i.e., changes in annual exports due to the implemented forestry operations expressed in kg ha(-1). We introduce here a specific concentration approach as a method to estimate the impact of clear-cutting on nutrient concentrations and export in headwater streams. This new method is potentially a more dynamic and flexible tool to estimate nutrient loads caused by forestry, because variation in annual runoff can be taken into account in load assessments. We combined water quality data from eight boreal headwater catchment pairs located in Finland and Sweden, where the effect of clear-cutting on stream water quality has been studied experimentally. Statistically significant specific concentration values could be produced for total nitrogen, nitrate, ammonium, and phosphate. The significant increases in the concentrations of these nutrients occurred between 2 and 6 years after clear-cutting. Significant specific concentration values could not be produced for total phosphorus and total organic carbon with the whole dataset, although in some single studies significant increases in their concentrations after clear-cutting were observed. The presented method enables taking into account variation in runoff, temporal dynamics of effects, and the proportional size of the treated area in load calculations. The number of existing studies considering large site-specific variation in responses to clear-cutting is small, and therefore further empirical studies are needed to improve predictive capabilities of the specific concentration values.

  8. Bibliography of selected water-resources information for the Arkansas River basin in Colorado through 1985

    USGS Publications Warehouse

    Kuzmiak, John M.; Strickland, Hyla H.

    1994-01-01

    The Arkansas River basin composes most of southeastern Colorado, and the numerous population centers and vast areas of agricultural development are located primarily in the semiarid part of the basin east of the Continental Divide. Because effective management and development of water resources in this semiarid area are essential to the viability of the basin, many hydrologic data- collection programs and investigations have been done. This report contains a bibliography of selected water-resources information about the basin, including regularly published information and special investigations, from Federal, State, and other organizations. To aid the reader, the infor- mation is indexed by author, subject, county, and hydrologic unit (drainage basin).

  9. Relations of Principal Components Analysis Site Scores to Algal-Biomass, Habitat, Basin-Characteristics, Nutrient, and Biological-Community Data in the Whitewater River and East Fork White River Basins, Indiana, 2002

    USGS Publications Warehouse

    Caskey, Brian J.; Frey, Jeffrey W.; Lowe, B. Scott

    2007-01-01

    Data were gathered from May through September 2002 at 76 randomly selected sites in the Whitewater River and East Fork White River Basins, Indiana, for algal biomass, habitat, nutrients, and biological communities (fish and invertebrates). Basin characteristics (land use and drainage area) and biolog-ical-community attributes and metric scores were determined for the basin of each sampling site. Yearly Principal Compo-nents Analysis site scores were calculated for algal biomass (periphyton and seston). The yearly Principal Components Analysis site scores for the first axis (PC1) were related using Spearman's rho to the seasonal algal-biomass, basin-charac-teristics, habitat, seasonal nutrient, and biological-community attribute and metric score data. The periphyton PC1 site score was not significantly related to the nine habitat or 12 nutrient variables examined. One land-use variable, drainage area, was negatively related to the periphyton PC1. Of the 43 fish-community attributes and metrics examined, the periphyton PC1 was negatively related to one attribute (large-river percent) and one metric score (car-nivore percent metric score). It was positively related to three fish-community attributes (headwater percent, pioneer percent, and simple lithophil percent). The periphyton PC1 was not statistically related to any of the 21 invertebrate-community attributes or metric scores examined. Of the 12 nutrient variables examined two were nega-tively related to the seston PC1 site score in two seasons: total Kjeldahl nitrogen (July and September), and TP (May and September). There were no statistically significant relations between the seston PC1 and the five basin-characteristics or nine habitat variables examined. Of the 43 fish-community attributes and metrics examined, the seston PC1 was positively related to one attribute (headwater percent) and negatively related to one metric score (large-river percent metric score) . Of the 21 invertebrate-community attributes

  10. Reserves in western basins

    SciTech Connect

    Caldwell, R.H.; Cotton, B.W.

    1995-04-01

    The objective of this project is to investigate the reserves potential of tight gas reservoirs in three Rocky Mountain basins: the Greater Green River (GGRB), Uinta and Piceance basins. The basins contain vast gas resources that have been estimated in the thousands of Tcf hosted in low permeability clastic reservoirs. This study documents the productive characteristics of these tight reservoirs, requantifies gas in place resources, and characterizes the reserves potential of each basin. The purpose of this work is to promote understanding of the resource and to encourage its exploitation by private industry. At this point in time, the GGRB work has been completed and a final report published. Work is well underway in the Uinta and Piceance basins which are being handled concurrently, with reports on these basins being scheduled for the middle of this year. Since the GGRB portion of the project has been completed, this presentation win focus upon that basin. A key conclusion of this study was the subdivision of the resource, based upon economic and technological considerations, into groupings that have distinct properties with regard to potential for future producibility, economics and risk profile.

  11. South American sedimentary basins

    SciTech Connect

    Urien, C.M.

    1984-04-01

    More than 64 sedimentary basins have been identified on the South American continent. According to their regional structural character and tectonic setting, they are classified in 4 super groups. About 20 interior or intracratonic basins occur on South American cratons (Guayanas, Brazilian, and Patagonian). In most cases, their sedimentary fill is Paleozoic or early Mesozoic. Rift or transverse grabens resulting from incipient sea floor spreading extend towards the continental margin. Seventeen basins are located along the Atlantic stable margin, and consist primarily of half grabens with downfaulted seaward blocks. These rifts (or pull-apart basins) were separated as results of the migration of the African and American continental blocks. Therefore the sedimentation is chiefly Cretaceous and Tertiary. On the western edge of South American cratons, almost 20 basins of downwarped blocks extend from Orinoco down to the Malvinas plateau in a relatively uninterrupted chain of retroarc basins, bordered by the Andean orogen. They lie on a flexured Precambrian and Paleozoic basement, and are highly deformed in the west (Subandean belt) due to the action of compressional forces caused by the tectonic influence of the Mesozoic Andean batholith. Westward, the Pacific margin is bordered by 27 foreland and forearc basins, which alternate from north to south on an unstable or quasistable margin, fringed by a trench and slope complex where the ocean crust is subducted beneath the continental plate.

  12. Sensitivity of stream basins in Shenandoah National Park to acid deposition

    USGS Publications Warehouse

    Lynch, D.D.; Dise, N.B.

    1985-01-01

    Six synoptic surveys of 56 streams that drain the Shenandoah National Park, Virginia, were conducted in cooperation with the University of Virginia to evaluate sensitivity of dilute headwater streams to acid deposition and to determine the degree of acidification of drainage basins. Flow-weighted alkalinity concentration of most streams is below 200 microequivalents per liter, which is considered the threshold of sensitivity. Streams draining resistant siliceous bedrocks have an extreme sensitivity (alkalinity below 20 microequivalents/L); those draining granite and granodiorite have a high degree of sensitivity (20 to 100 microequivalents/L); and streams draining metamorphosed volcanics have moderate to marginal sensitivity (100 to 200 microequivalents/L). A comparison of current stream water chemistry to that predicted by a model based on carbonic acid weathering reactions suggests that all basins in the Park shows signs of acidification by atmospheric deposition. Acidification is defined as a neutralization of stream water alkalinity and/or an increase in the base cation weathering rate. Acidification averages 50 microequivalents/L, which is fairly evenly distributed in the Park. However, the effects of acidification are most strongly felt in extremely sensitive basins, such as those underlain by the Antietam Formation, which have stream water pH values averaging 4.99 and a mineral acidity of 7 microequivalents/L. (USGS)

  13. Flood of June 4, 2002, in the Indian Creek Basin, Linn County, Iowa

    USGS Publications Warehouse

    Eash, David A.

    2004-01-01

    Severe flooding occurred on June 4, 2002, in the Indian Creek Basin in Linn County, Iowa, following thunderstorm activity over east-central Iowa. The rain gage at Cedar Rapids, Iowa, recorded a 24-hour rainfall of 4.76 inches at 6:00 p.m. on June 4th. Radar indications estimated as much as 6 inches of rain fell in the headwaters of the Indian Creek Basin. Peak discharges on Indian Creek of 12,500 cubic feet per second at County Home Road north of Marion, Iowa, and 24,300 cubic feet per second at East Post Road in southeast Cedar Rapids, were determined for the flood. The recurrence interval for these peak discharges both exceed the theoretical 500-year flood as computed using flood-estimation equations developed by the U.S. Geological Survey. Information about the basin and flood history, the 2002 thunderstorms and associated flooding, and a profile of high-water marks are presented for selected reaches along Indian and Dry Creeks.

  14. Hydrograph sensitivity to estimates of map impervious cover: a WinHSPF BASINS case study

    NASA Astrophysics Data System (ADS)

    Endreny, Theodore A.; Somerlot, Christopher; Hassett, James M.

    2003-04-01

    The BASINS geographic information system hydrologic toolkit was designed to compute total maximum daily loads, which are often derived by combining water quantity estimates with pollutant concentration estimates. In this paper the BASINS toolkit PLOAD and WinHSPF sub-models are briefly described, and then a 0·45 km2 headwater watershed in the New York Croton River area is used for a case study illustrating a full WinHSPF implementation. The goal of the Croton study was to determine the sensitivity of WinHSPF hydrographs to changes in land cover map inputs. This scenario occurs when scaling the WinHSPF model from the smaller 0·45 km2 watershed to the larger 1000 km2 management basin of the entire Croton area. Methods used to test model sensitivity include first calibrating the WinHSPF hydrograph using research-monitored precipitation and discharge data together with high spatial resolution and accuracy land cover data of impervious and pervious areas, and then swapping three separate land cover files, known as GIRAS, MRLC, and DOQQ data, into the calibrated model. Research results indicated that the WinHSPF land cover swapping had peak flow sensitivity in December 2001 hydrographs between 35% underestimation and 20% overestimation, and that errors in land-cover-derived runoff ratios for storm totals and peak flows tracked with the land cover data estimates of impervious area.

  15. The Subject of Policy

    ERIC Educational Resources Information Center

    Bansel, Peter

    2015-01-01

    I work selectively with poststructuralist theories in order to give an account of the subject of policy as a constitutive relationship between social policy and the embodied human subject. Drawing on theories of subjectivity, narrative and governmentality, I articulate possibilities for analysing narrated accounts of experience as a mode of…

  16. Gendered Subjectivities of Spacetimematter

    ERIC Educational Resources Information Center

    Juelskjaer, Malou

    2013-01-01

    This paper investigates enactments of human subjectivities with a focus on how subjectivities may be studied if spatiality and temporality are taken up as constituting forces in the production of subjectivities. By reading poststructuralist feminist theorising, agential realism and empirical material diffractively through each other I re-situate…

  17. Population Structure in the Roundtail Chub (Gila robusta Complex) of the Gila River Basin as Determined by Microsatellites: Evolutionary and Conservation Implications

    PubMed Central

    Dowling, Thomas E.; Anderson, Corey D.; Marsh, Paul C.; Rosenberg, Michael S.

    2015-01-01

    Ten microsatellite loci were characterized for 34 locations from roundtail chub (Gila robusta complex) to better resolve patterns of genetic variation among local populations in the lower Colorado River basin. This group has had a complex taxonomic history and previous molecular analyses failed to identify species diagnostic molecular markers. Our results supported previous molecular studies based on allozymes and DNA sequences, which found that most genetic variance was explained by differences among local populations. Samples from most localities were so divergent species-level diagnostic markers were not found. Some geographic samples were discordant with current taxonomy due to admixture or misidentification; therefore, additional morphological studies are necessary. Differences in spatial genetic structure were consistent with differences in connectivity of stream habitats, with the typically mainstem species, G. robusta, exhibiting greater genetic connectedness within the Gila River drainage. No species exhibited strong isolation by distance over the entire stream network, but the two species typically found in headwaters, G. nigra and G. intermedia, exhibited greater than expected genetic similarity between geographically proximate populations, and usually clustered with individuals from the same geographic location and/or sub-basin. These results highlight the significance of microevolutionary processes and importance of maintaining local populations to maximize evolutionary potential for this complex. Augmentation stocking as a conservation management strategy should only occur under extreme circumstances, and potential source populations should be geographically proximate stocks of the same species, especially for the headwater forms. PMID:26473600

  18. Population Structure in the Roundtail Chub (Gila robusta Complex) of the Gila River Basin as Determined by Microsatellites: Evolutionary and Conservation Implications.

    PubMed

    Dowling, Thomas E; Anderson, Corey D; Marsh, Paul C; Rosenberg, Michael S

    2015-01-01

    Ten microsatellite loci were characterized for 34 locations from roundtail chub (Gila robusta complex) to better resolve patterns of genetic variation among local populations in the lower Colorado River basin. This group has had a complex taxonomic history and previous molecular analyses failed to identify species diagnostic molecular markers. Our results supported previous molecular studies based on allozymes and DNA sequences, which found that most genetic variance was explained by differences among local populations. Samples from most localities were so divergent species-level diagnostic markers were not found. Some geographic samples were discordant with current taxonomy due to admixture or misidentification; therefore, additional morphological studies are necessary. Differences in spatial genetic structure were consistent with differences in connectivity of stream habitats, with the typically mainstem species, G. robusta, exhibiting greater genetic connectedness within the Gila River drainage. No species exhibited strong isolation by distance over the entire stream network, but the two species typically found in headwaters, G. nigra and G. intermedia, exhibited greater than expected genetic similarity between geographically proximate populations, and usually clustered with individuals from the same geographic location and/or sub-basin. These results highlight the significance of microevolutionary processes and importance of maintaining local populations to maximize evolutionary potential for this complex. Augmentation stocking as a conservation management strategy should only occur under extreme circumstances, and potential source populations should be geographically proximate stocks of the same species, especially for the headwater forms.