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Sample records for affect soil erosion

  1. Wind erosion as affected by soil temporal variation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The wind erosion prediction system (WEPS) requires information about numerous spatial and temporal variables and complex interactions that affect erosion, particulate matter (PM 10 and 2.5) generation, and nutrient loss. Abrasion of clods and crusts, aggregate slaking, and dispersion during wind and...

  2. Using Gypsum to Affect Soil Erosion Processes and Water Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A driving force in soil erosion is the low electrolyte content of rain water. Various electrolyte sources have proven useful in serving as electrolyte sources such as phosphogypsum, lime and various salts, however, each has other potential problems. We performed a number of studies on low cost gypsu...

  3. How irrigation affects soil erosion estimates of RUSLE2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RUSLE2 is a robust and computationally efficient conservation planning tool that estimates soil, climate, and land management effects on sheet and rill erosion and sediment delivery from hillslopes, and also estimates the size distribution and clay enrichment of sediment delivered to the channel sys...

  4. Hydrologic and Erosion Models To Assess Land Use and Management Practices Affecting Soil Erosion

    SciTech Connect

    Wigmosta, Mark S.; Lane, Leonard J.; Tagestad, Jerry D.; Coleman, Andre M.

    2009-01-01

    We developed a new, coupled, hydrologic-erosion modeling and a targeted field data-collection program to quantify soil erosion rates and sediment yield in arid regions. While the methodology has a wide range of actual and potential applications, we use military training activities as an example. The methodology is applied at the Yakima Training Center (YTC) in south-central Washington, USA where most erosion and transport occurs during extreme events of short duration, often associated with rapid rain-induced snowmelt on frozen soil. The distributed hydrologic and soil erosion modeling system is used to simulate continuous water balance and soil thermal state throughout all seasons of the year. We estimated surface runoff and sediment yield for relatively undisturbed areas as well as from roads, firebreaks, and vehicle tracks associated with training activities at the site. Field data were collected on over 100 hillslope profile transects across the YTC to parameterize, test, and evaluate the linked modeling system. We successfully validated the modeling system against measured sediment yield from twelve sedimentation ponds within the YTC. The simulation results are superior to those from two currently used models, which help to illustrate applicability of the new erosion prediction technology.

  5. Spatial and temporal variability of soil hydraulic properties of topsoil affected by soil erosion

    NASA Astrophysics Data System (ADS)

    Nikodem, Antonin; Kodesova, Radka; Jaksik, Ondrej; Jirku, Veronika; Klement, Ales; Fer, Miroslav

    2014-05-01

    This study is focused on the comparison of soil hydraulic properties of topsoil that is affected by erosion processes. In order to include variable morphological and soil properties along the slope three sites - Brumovice, Vidim and Sedlčany were selected. Two transects (A, B) and five sampling sites along each one were chosen. Soil samples were taken in Brumovice after the tillage and sowing of winter wheat in October 2010 and after the wheat harvest in August 2011. At locality Vidim and Sedlčany samples were collected in May and August 2012. Soil hydraulic properties were studied in the laboratory on the undisturbed 100-cm3 soil samples placed in Tempe cells using the multi-step outflow test. Soil water retention data points were obtained by calculating water balance in the soil sample at each pressure head step of the experiment. The single-porosity model in HYDRUS-1D was applied to analyze the multi-step outflow and to obtain the parameters of soil hydraulic properties using the numerical inversion. The saturated hydraulic conductivities (Ks) and unsaturated hydraulic conductivities (Kw) for the pressure head of -2 cm of topsoil were also measured after the harvest using Guelph permeameter and Minidisk tensiometer, respectively. In general soil water retention curves measured before and after vegetation period apparently differed, which indicated soil material consolidation and soil-porous system rearrangement. Soil water retention curves obtained on the soil samples and hydraulic conductivities measured in the field reflected the position at the elevation transect and the effect of erosion/accumulation processes on soil structure and consequently on the soil hydraulic properties. The highest Ks values in Brumovice were obtained at the steepest parts of the elevation transects, that have been the most eroded. The Ks values at the bottom parts decreased due to the sedimentation of eroded soil particles. The change of the Kw values along transects didn't show

  6. Drainage and leaching dynamics in a cropped hummocky soil landscape with erosion-affected pedogenesis

    NASA Astrophysics Data System (ADS)

    Gerke, Horst H.; Rieckh, Helene; Sommer, Michael

    2016-04-01

    Hummocky soil landscapes are characterized by 3D spatial patterns of soil types that result from erosion-affected pedogenesis. Due to tillage and water erosion, truncated profiles have been formed at steep and mid slopes and colluvial soils at hollows. Pedogenetic variations in soil horizons at the different hillslope positions suggested feedback effects between erosion affected soil properties, the water balances, and the crop growth and leaching rates. Water balance simulations compared uniform with hillslope position-specific crop and root growths for soils at plateau, flat mid slope, steep slope, and hollow using the Hydrus-1D program. The boundary condition data were monitored at the CarboZALF-D experimental field site, which was cropped with perennial lucerne (Medicago sativa L.) in 2013 and 2014. Crop and root growth was assumed proportional to observed leaf area index (LAI). Fluxes of dissolved organic and inorganic carbon (DOC, DIC) were obtained from simulated water fluxes and measured DOC and DIC concentrations. For the colluvic soil, the predominately upward flow led to a net input in DIC and DOC. For the truncated soils at steep slopes, a reduced crop growth caused an relative increase in drainage, suggesting an accelerated leaching, which in the long term could accelerate the soil development and more soil variations along eroding hillslopes in arable soil landscapes.

  7. Soil hydraulic properties of topsoil along two elevation transects affected by soil erosion

    NASA Astrophysics Data System (ADS)

    Nikodem, Antonin; Kodesova, Radka; Jaksik, Ondrej; Jirku, Veronika; Fer, Miroslav; Klement, Ales; Zigova, Anna

    2013-04-01

    This study is focused on the comparison of soil hydraulic properties of topsoil that is affected by erosion processes. Studied area is characterized by a relatively flat upper part, a tributary valley in the middle and a colluvial fan at the bottom. Haplic Chernozem reminded at the flat upper part of the area. Regosols were formed at steep parts of the valley. Colluvial Chernozem and Colluvial soils were formed at the bottom parts of the valley and at the bottom part of the studied field. Two transects and five sampling sites along each one were selected. The soil-water retention curves measured on the undisturbed 100-cm3 soil samples taken after the tillage and sowing of winter wheat (October 2010) were highly variable and no differences between sampling sites within the each transect were detected. Variability of soil-water retention curves obtained on soil samples taken after the wheat harvest (August 2011) considerably deceased. The parts of the retention curves, which characterized the soil matrix, were very similar. The main differences between the soil-water retention curves were found in parts, which corresponded to larger capillary pores. The fractions of the large capillary pores (and also saturated soil water-contents) were larger after the harvest (soil structure reestablishment) than that after the tillage and sawing (soil structure disturbance). Greater amount of capillary pores was observed in soils with better developed soil structure documented on the micromorphological images. The saturated hydraulic conductivities (Ks) and unsaturated hydraulic conductivities (K) for the pressure head of -2 cm of topsoil were also measured after the wheat harvest using Guelph permeameter and Minidisk tensiometer, respectively. The highest Ks values were obtained at the steepest parts of the elevation transects, that have been the most eroded. The Ks values at the bottom parts decreased due to the sedimentation processes of eroded soil particles. The change of the

  8. Monitoring of soil water storage along elevation transech on morphological diverse study-sites affected by soil erosion

    NASA Astrophysics Data System (ADS)

    Jaksik, Ondrej; Kodesova, Radka; Nikodem, Antonin; Fer, Miroslav; Klement, Ales; Kratina, Josef

    2015-04-01

    Soil water availability is one of the key factors determining plant growth. Spatial distribution of soil water content is influenced by many factors. For the field-scale, one of the most important factors is terrain and its shape. The goal of our study was to characterize soil water storage within the soil profile with respect to terrain attributes. Two morphologically diverse study sites were chosen, in order to monitor soil water storage during vegetation season. The first site Brumovice in located in the Southern Moravian Region. The original soil unit was Haplic Chernozem developed on loess, which was gradually degraded by soil erosion. In the steepest parts, due to substantial loss of soil material, soil is transformed to Regosol. As a result of consequently sedimentation of previously eroded material in toe slopes and terrain depressions colluvial soils are formed. The second site Vidim is placed in the Central Bohemia. Dominant soil unit in wider area is Haplic Luvisol on loess loam. Similar process of progressive soil transformation was identified. On each study site, two elevation transects were delimited, where each consists of 5 monitoring spots. Access tubes were installed in order to measure soil moisture in six different depths (10, 20, 30 40, 60 a 100 cm) using Profile Probe PR2. The monitoring was conducted during vegetation season: April - July 2012 in Brumovice and May - July 2013 in Vidim. The average soil water contents were calculated for following three layers: topsoil A (0-20 cm), subsoil B (20-40cm), and substrate (40-100cm). The soil water storage within the soil profile was also expressed. Sensors TMS3 were also used for continual soil water content monitoring in the depth of 0-15 cm. In addition undisturbed soil samples were taken from topsoil to measure soil hydraulic properties using the multistep outflow experiment. Data were used to assess retention ability of erosion affected soils. The soil water storage and particularly average

  9. Soil properties governing soil erosion affected by cropping systems in the U.S. Pacific Northwest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the low-precipitation zone (<300 mm annual precipitation) of the inland US Pacific Northwest, no-tillage spring cereal rotations are being examined as alternatives to the traditional winter wheat - summer fallow rotation to control wind erosion. There is limited information, however, regarding t...

  10. Soil Erosion by Water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion by water, the wearing away of the earth's surface by the forces of water and gravity, consists of rock or soil particle dislodgement, entrainment, transport, and deposition. This sequence of events occurs over a wide range of temporal and spatial scales, from raindrop splash moving par...

  11. Factors affecting soil cohesion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erodibility is a measure of a soil’s resistance against erosive forces and is affected by both intrinsic (or inherent) soil property and the extrinsic condition at the time erodibility measurement is made. Since soil erodibility is usually calculated from results obtained from erosion experimen...

  12. Land factors affecting soil erosion during snow melting: a case study from Lebanon

    NASA Astrophysics Data System (ADS)

    Darwich, Talal

    2014-05-01

    Soil erosion is one of the major problems facing the mountainous agricultural lands in Lebanon. In order to assess the land factors acting on soil erosion; a study was conducted in the upper watershed of Ibrahim River in the spring months of April, May and June. Water and bed load sediments from six locations alimented by six sub-basins were sampled. Four sub-basins (1, 2, 3 and 6) were dominated by agricultural lands while lands in sub-basins 4 and 7 were occupied by grassland and bare soils. The highest quantities of suspended sediments were found in waters originating from watersheds dominated by agricultural lands, such as Location 2 (713.72 mg L-1 in April 2012). Low clay content and the combination of land occupation (orchards = 71%) and slope (20.7 degrees) caused this ecosystem disturbance. Locations 1, 2, 3 and 6 were alimented by runoff water due to the melting of the snow. For this, the concentrations of sediments decreased by 4 fold between April and May in sub-basin 1 and by 11-14 fold in sub-basins 2, 3 and 6. Globally, some 1669.4 tons of sediments were delivered in the upper river during April. Bed load sediments were separated into 4 classes according to their size. The size of the particles found in the bed load reflected to a large extent the type of soils surrounding the watershed. The range of sand in the regions surrounding locations 6 and 7 was 64% and 82%, while the average in the bed load was 80.9% and 78.25% respectively. The silt content in locations 2, 3 and 5 was well reflected in the concentrations of silt in the bed load. In bed load samples, the exchangeable potassium ranged from 70-250 mg kg-1 in sub-basins dominated by agricultural lands against 20-50 mg kg-1 in sub-basins dominated by grassland and bare rocks. Further quantitative studies need to be conducted especially during the first rains to fully estimate the water load sediments after a prolonged dry season, characterizing the east Mediterranean. Action must be taken for

  13. Soil organic matter composition along a slope in an erosion-affected arable landscape in North East Germany

    NASA Astrophysics Data System (ADS)

    Ellerbrock, Ruth, H.; Gerke, Horst, H.; Deumlich, Detlef

    2016-04-01

    In hummocky landscapes, soil erosion is forming truncated profiles at steep slope positions and colluvial soils in topographic depressions thereby affecting soil organic carbon (SOC) storage. However, the knowledge on the spatial distribution and composition of differently stable organic matter (OM) fractions in arable landscapes is still limited. Here, amount and composition of OM from top- and subsoil horizons at eroded, colluvic, and non -eroded slope positions were compared. The horizons were from a Luvisol at plateau (LV), an eroded Luvisol (eLV) at mid slope (6%slope gradient), a calcaric Regosol (caRG) at steep slope (13%), and a colluvic Regosol (coRG) at hollow position. Water soluble (OM-W) and pyrophosphate soluble (OM-PY) fractions were extracted sequentially. Soil samples, OM fractions, and extraction residues were analyzed with transmission Fourier transform infrared (FTIR) spectroscopy. The soluble fractions were 3% of SOC for OM-W and 15% of SOC for OM-PY. For topsoil samples, extract ion rates were independent of slope position. The highest intensities of both, C-H (alkyl groups) and C=O (carboxyl groups) absorption band, were found in FTIR spectra of OM-PY from top and subsoil horizons at the steep slope position (caRG). The C-H/C=O ratio in OM-PY decreased with increasing contents of oxalate soluble Fe and Al oxides from steep slope (0.25 for caRG-Ap) towards plateau, and hollow position (0.09 for coRG-Ap) except for the Bt -horizons. This relation is reflecting that the down slope-deposited Ap material, which is higher in poorly crystalline Fe an d Al oxides, consists of relatively stable OM. This OM is enriched in C=O groups that are known for their interaction with soil minerals. These OM-mineral interactions may help explaining C storage in arable soil landscapes.

  14. Soil Erosion and Agricultural Sustainability

    NASA Astrophysics Data System (ADS)

    Montgomery, D. R.

    2009-04-01

    Data drawn from a global compilation of studies support the long articulated contention that erosion rates from conventionally plowed agricultural fields greatly exceed rates of soil production, erosion under native vegetation, and long-term geological erosion. Whereas data compiled from around the world show that soil erosion under conventional agriculture exceeds both rates of soil production and geological erosion rates by up to several orders of magnitude, similar global distributions of soil production and geological erosion rates suggest an approximate balance. Net soil erosion rates in conventionally plowed fields on the order of 1 mm/yr can erode typical hillslope soil profiles over centuries to millennia, time-scales comparable to the longevity of major civilizations. Well-documented episodes of soil loss associated with agricultural activities date back to the introduction of erosive agricultural methods in regions around the world, and stratigraphic records of accelerated anthropogenic soil erosion have been recovered from lake, fluvial, and colluvial stratigraphy, as well as truncation of soil stratigraphy (such as truncated A horizons). A broad convergence in the results from studies based on various approaches employed to study ancient soil loss and rates of downstream sedimentation implies that widespread soil loss has accompanied human agricultural intensification in examples drawn from around the world. While a broad range of factors, including climate variability and society-specific social and economic contexts — such as wars or colonial relationships — all naturally influence the longevity of human societies, the ongoing loss of topsoil inferred from studies of soil erosion rates in conventional agricultural systems has obvious long-term implications for agricultural sustainability. Consequently, modern agriculture — and therefore global society — faces a fundamental question over the upcoming centuries. Can an agricultural system

  15. Soil erosion and the global carbon budget.

    PubMed

    Lal, R

    2003-07-01

    Soil erosion is the most widespread form of soil degradation. Land area globally affected by erosion is 1094 million ha (Mha) by water erosion, of which 751 Mha is severely affected, and 549 Mha by wind erosion, of which 296 Mha is severely affected. Whereas the effects of erosion on productivity and non-point source pollution are widely recognized, those on the C dynamics and attendant emission of greenhouse gases (GHGs) are not. Despite its global significance, erosion-induced carbon (C) emission into the atmosphere remains misunderstood and an unquantified component of the global carbon budget. Soil erosion is a four-stage process involving detachment, breakdown, transport/redistribution and deposition of sediments. The soil organic carbon (SOC) pool is influenced during all four stages. Being a selective process, erosion preferentially removes the light organic fraction of a low density of <1.8 Mg/m(3). A combination of mineralization and C export by erosion causes a severe depletion of the SOC pool on eroded compared with uneroded or slightly eroded soils. In addition, the SOC redistributed over the landscape or deposited in depressional sites may be prone to mineralization because of breakdown of aggregates leading to exposure of hitherto encapsulated C to microbial processes among other reasons. Depending on the delivery ratio or the fraction of the sediment delivered to the river system, gross erosion by water may be 75 billion Mg, of which 15-20 billion Mg are transported by the rivers into the aquatic ecosystems and eventually into the ocean. The amount of total C displaced by erosion on the earth, assuming a delivery ratio of 10% and SOC content of 2-3%, may be 4.0-6.0 Pg/year. With 20% emission due to mineralization of the displaced C, erosion-induced emission may be 0.8-1.2 Pg C/year on the earth. Thus, soil erosion has a strong impact on the global C cycle and this component must be considered while assessing the global C budget. Adoption of

  16. The biogeochemical footprint of agricultural soil erosion

    NASA Astrophysics Data System (ADS)

    Govers, Gerard; Van Oost, Kristof; Wang, Zhengang

    2015-04-01

    Global biogeochemical cycles are a key component of the functioning of the Earth System: these cycles are all, to a varying extent, disturbed by human activities which not only has dramatic consequences for the global climate but also for the acidity of the world's oceans. It is only relatively recently that the role of lateral fluxes related to surface water movement and soil erosion and deposition (and the way those fluxes are modified by human action) is explicitly considered by the scientific community. In this paper we present an overview of our present-day understanding of the role of agricultural soil erosion in the global cycles of carbon, nitrogen, phosphorous and silica. We discuss the major processes through which erosion affects these global cycles and pay particular attention to the knowledge gaps that prevent us from accurately assessing the impact of soil erosion on global biogeochemical cycling at different temporal scales. Furthering our understanding (and better constraining our estimates) will require progress both in terms of model development and process understanding. Research needs can be most clearly identified with respect to soil organic carbon: (i) at present, large-scale soil erosion (and deposition) models are poorly constrained so that the amount of carbon mobilised by erosion (and its fate) cannot be accurately estimated and (ii) the fate of soil organic carbon buried by deposition or delivered to river network is poorly understood. Uncertainties for N, P and Si are larger than those for C as we have less information on the amount of these elements stored in agricultural soils and/or do not fully understand how these elements cycle through the soil/plant system. Agricultural soil erosion does not affect soil functioning through its effect on biogeochemical cycling. Erosion directly affects soil hydrological functioning and is likely to affect weathering processes and soil production. Addressing all these issues requires the

  17. Soil erosion in Iran: Issues and solutions

    NASA Astrophysics Data System (ADS)

    Hamidreza Sadeghi, Seyed; Cerdà, Artemi

    2015-04-01

    Iran currently faces many soil erosion-related problems (see citations below). These issues are resulted from some inherent characteristic and anthropogenic triggering forces. Nowadays, the latter plays more important rule to accelerate the erosion with further emphasis on soil erosion-prone arid and semi arid regions of the country. This contribution attempts to identify and describe the existing main reasons behind accelerated soil erosion in Iran. Appropriate solutions viz. structural and non-structural approaches will be then advised to combat or minimise the problems. Iran can be used as a pilot research site to understand the soil erosion processes in semiarid, arid and mountainous terrain and our research will review the scientific literature and will give an insight of the soil erosion rates in the main factors of the soil erosion in Iran. Key words: Anthropogenic Erosion, Land Degradation; Sediment Management; Sediment Problems Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and PREVENTING AND REMEDIATING DEGRADATION OF SOILS IN EUROPE THROUGH LAND CARE (RECARE)FP7-ENV-2013- supported this research. References Aghili Nategh, N., Hemmat, A., & Sadeghi, M. (2014). Assessing confined and semi-confined compression curves of highly calcareous remolded soil amended with farmyard manure. Journal of Terramechanics, 53, 75-82. Arekhi, S., Bolourani, A. D., Shabani, A., Fathizad, H., Ahamdy-Asbchin, S. 2012. Mapping Soil Erosion and Sediment Yield Susceptibility using RUSLE, Remote Sensing and GIS (Case study: Cham Gardalan Watershed, Iran). Advances in Environmental Biology, 6(1), 109-124. Arekhi, S., Shabani, A., Rostamizad, G. 2012. Application of the modified universal soil loss equation (MUSLE) in prediction of sediment yield (Case study: Kengir Watershed, Iran). Arabian Journal of Geosciences, 5(6), 1259-1267.Sadeghi, S. H., Moosavi, V., Karami, A., Behnia, N. 2012. Soil erosion assessment and prioritization of affecting factors at plot

  18. Soil Erosion. LC Science Tracer Bullet.

    ERIC Educational Resources Information Center

    Buydos, John F., Comp.

    Soil erosion is the detachment and movement of topsoil or soil material from the upper part of the soil profile. It may occur in the form of rill, gully, sheet, or wind erosion. Agents of erosion may be water, wind, glacial ice, agricultural implements, machinery, and animals. Soil conservation measures require a thorough understanding of the…

  19. Does soil burn severity affect the post-fire runoff and interrill erosion response? A review based on meta-analysis of field rainfall simulation data

    NASA Astrophysics Data System (ADS)

    Vieira, D. C. S.; Fernández, C.; Vega, J. A.; Keizer, J. J.

    2015-04-01

    Soil burn severity has been widely used to describe the impacts of fire on soils and is increasingly being recognised as a decisive factor controlling post-fire erosion rates. However, there is no unique definition of the term and the relationship between soil burn severity and post-fire hydrological and erosion response has not yet been fully established. The objective of this work was to review the existing literature on the role of soil burn severity on post-fire runoff and erosion ratios. To this end, a meta-analysis was carried out of the runoff and inter-rill erosion data from field rainfall simulation experiments (RSE's) that compared burnt and unburnt conditions. In this study, 109 individual observations were analysed that covered a wide geographical range, various types of land cover (forest, shrubland, and grassland) and two types of fire types (wildfire and prescribed fire). The effect size of the post-fire runoff and erosion response was determined for four key factors: (i) soil burn severity; (ii) time-since-fire; (iii) rainfall intensity; and (iv) bare soil cover. Statistical meta-analysis showed that fire occurrence had a significant effect on the hydrological and erosive response. However, this effect was only significantly higher with increasing soil burn severity for inter-rill erosion, and not for runoff. This study furthermore highlighted the incoherencies between existing burn severity classifications, and proposed an unambiguous classification.

  20. Soil erosion-runoff relationships: insights from laboratory studies

    NASA Astrophysics Data System (ADS)

    Mamedov, Amrakh; Warrington, David; Levy, Guy

    2016-04-01

    Understanding the processes and mechanisms affecting runoff generation and subsequent soil erosion in semi-arid regions is essential for the development of improved soil and water conservation management practices. Using a drip type laboratory rain simulator, we studied runoff and soil erosion, and the relationships between them, in 60 semi-arid region soils varying in their intrinsic properties (e.g., texture, organic matter) under differing extrinsic conditions (e.g., rain properties, and conditions prevailing in the field soil). Both runoff and soil erosion were significantly affected by the intrinsic soil and rain properties, and soil conditions within agricultural fields or watersheds. The relationship between soil erosion and runoff was stronger when the rain kinetic energy was higher rather than lower, and could be expressed either as a linear or exponential function. Linear functions applied to certain limited cases associated with conditions that enhanced soil structure stability, (e.g., slow wetting, amending with soil stabilizers, minimum tillage in clay soils, and short duration exposure to rain). Exponential functions applied to most of the cases under conditions that tended to harm soil stability (e.g., fast wetting of soils, a wide range of antecedent soil water contents and rain kinetic energies, conventional tillage, following biosolid applications, irrigation with water of poor quality, consecutive rain simulations). The established relationships between runoff and soil erosion contributed to a better understanding of the mechanisms governing overland flow and soil loss, and could assist in (i) further development of soil erosion models and research techniques, and (ii) the design of more suitable management practices for soil and water conservation.

  1. Three Gorges Reservoir Area: soil erosion under natural condition vs. soil erosion under current land use

    NASA Astrophysics Data System (ADS)

    Schönbrodt, Sarah; Behrens, Thorsten; Scholten, Thomas

    2010-05-01

    Apparently, the current most prominent human-induced example for large scale environmental impact is the Three Gorges Dam in China. The flooding alongside the Yangtze River, and its tributaries results in a vast loss of settlement and farmland area with productive, fertile valley soils. Due to the associated high land use dynamic on uphill-sites, the soil resources are underlying high land use pressure. Within our study, the soil erosion under natural conditions is compared to the soil erosion under current land use after the impoundment. Both were modeled using the empirical Universal Soil Loss Equation (USLE) which is able to predict long-term annual soil loss with limited data. The database consists of digital terrain data (45 m resolution DEM, erosive slope length based on Monte-Carlo-Aggregation according to Behrens et al. (2008)), field investigations of recent erosion forms, and literature studies. The natural disposition to soil erosion was calculated considering the USLE factors R, S, and K. The soil erosion under current land use was calculated taking into account all USLE factors. The study area is the catchment of the Xiangxi River in the Three Gorges Reservoir area. Within the Xiangxi Catchment (3,200 km²) the highly dynamic backwater area (580 km²), and two micro-scale study sites (Xiangjiaba with 2.8 km², and Quyuan with 88 km²) are considered more detailed as they are directly affected by the river impoundment. Central features of the Xiangxi Catchment are the subtropical monsoon climate, an extremely steep sloping relief (mean slope angle 39°, SD 22.8°) artificially fractured by farmland terraces, and a high soil erodibility (mean K factor 0.37, SD 0.13). On the catchment scale the natural disposition to soil erosion makes up to mean 518.0 t ha-1 a-1. The maximum potential soil loss of 1,730.1 t ha-1 a-1 under natural conditions is reached in the Quyuan site (mean 635.8 t ha-1 a-1) within the backwater area (mean 582.9 t ha-1 a-1). In the

  2. Evaluation of soil factors controlling gully erosion

    NASA Astrophysics Data System (ADS)

    Ollobarren, Paul; Giménez, Rafael; Ángel Campo, Miguel; Casalí, Javier

    2015-04-01

    Current models for prediction of (ephemeral) gully erosion rely mainly on topographic factors while soil conditions are almost neglected. However, soil erodibility is essential for analyzing and properly modeling gully erosion. But, despite the wealth of studies to characterize soil vulnerability to gully erosion, a universal approach is still lacking. Moreover, a useful and feasible soil characterization for gully erosion prediction at large scale should be based on simple, quick, repeatable and relatively inexpensive tests to perform. In this work an experimental approach to quantify soil contribution on gully erosion is proposed. From simple methodologies and techniques found in the literature for assessing physical-chemical properties of the soil, a large pool of variables -that presumably underpin gully erosion- were defined. These methodologies includes the use of vane shear apparatus, penetrometers and a mini-rain simulator as well as some current (modified) laboratory tests for assessing soil crustability and erodibility. Thirteen ephemeral gullies developed under different soil condition in agricultural fields of Navarre (Spain) were selected for experiments. Then, the aforementioned variables were calculated for each of the gullies through field and lab experiments. Furthermore, the most relevant variables were detected by means of multivariate analysis and their contribution to gully erosion was finally quantified by using multiple regression analysis. In addition, gully erosion rates of typical agricultural fields are given.

  3. Redistribution of soil biota by rainfall erosion

    NASA Astrophysics Data System (ADS)

    Baxter, Craig; Rowan, John; McKenzie, Blair; Neilson, Roy

    2013-04-01

    Soil is central to the provision of multiple ecosystem services that sustain life through a myriad of chemical, physical and biological processes. One of the greatest threats to soil is erosion, a natural process accelerated by human activities. Elevated erosion rates are common in agro-ecosystems causing both direct physical impacts (e.g. soil loss), and indirect biogeochemical consequences, which ultimately leads to impaired ecosystem functioning. The consequences of erosion on soil biota have hitherto been ignored, yet biota have fundamental roles in the provision of soil ecosystem services. To our knowledge few studies have addressed the gap between erosion and impacts on soil biota. Here we use soil nematodes as a model organism for assessing erosion impacts on soil (micro) fauna in temperate agro-ecosystems. Soil nematodes are ubiquitous, abundant, are represented at all levels in soil food webs and can be categorised into a range of trophic or functional groups. To quantify transport of nematodes and gain a better understanding of erosive mechanisms responsible, we measured their export from small erosion plots (0.0625m2) under a fixed-intensity design rainstorm (6mm min-1 duration: 3 min) over six slope angles (4° - 24°) and three soil texture classes (sandy silt, silty sand, silt). Runoff and eroded sediment were collected for each plot (four replicate runs), and a suite of biological and physico-chemical parameters measured. Results confirmed that, similar to soil particles, nematodes were exported at rates influenced by slope angle and soil texture. These experiments, linked with field and catchment-scale equivalents, are designed to elucidate the links between soil erosion and provision of ecosystem services and to inform biodiversity-sensitive soil and water conservation practices.

  4. Quantification Of Erosion Rates Of Agriculturally Used Soils By Artificial

    NASA Astrophysics Data System (ADS)

    Jha, Abhinand

    2010-05-01

    0.0.1 1. Introduction to soil erosion measurement by radionuclides Soil erosion by water, wind and tillage affects both agriculture and the natural environment. Studying this phenomenon would be one of the advancements in science. Soil erosion occurs worldwide and since the last two decades it has been a main topic of discussion all over the world. The use of environmental radionuclides such as 90Sr, 137Cs to study medium term soil erosion (40 yrs) started in the early 1990's. Using these new techniques better knowledge about erosion can be gained and this knowledge can be implemented for erosion risk management. The erosion and sedimentation study by using man-made and natural radioisotopes is a key technique, which has developed over the past 30 years. Fallout 137Cs and Cosmogenic 7Be are radionuclides that have been used to provide independent measurements of soil-erosion and sediment-deposition rates and patterns [1] [2] [3] [4]. Erosion measurements using radionuclides 137Cs, 7Be Caesium-137 from atmospheric nuclear-weapons tests in the 1950s and 1960s (Fig.1) is a unique tracer of erosion and sedimentation, since there are no natural sources of 137Cs. Unique events such as the Chernobyl accident in April 1986 caused regional dispersal of 137Cs that affects the total global deposition budget. This yearly pattern of fallout can be used to develop a chronology of deposition horizons in lakes, reservoirs, and floodplains. 137Cs can be easily measured by gamma spectroscopy. Using 137Cs is a fast and cheap method to study erosion-deposition processes compared to the traditional methods like silt bags. PIC Figure 1: Global 137Cs fallout (Modified from SAAS Bulletin 353, Part E, DDR, 1986) When 137Cs, 7Be reach the soil surface by wet and dry deposition, they are quickly and strongly adsorbed by ion exchange and are essentially non exchangeable in most environments. Each radionuclide is distributed differently in the soil because of differences in half-lives (30 yrs

  5. Study on soil erosion in Hudan River basin based on TM imagery

    NASA Astrophysics Data System (ADS)

    Chao, Zhenhua; Yang, Yongshun; Gao, Xiaohong

    2014-11-01

    Huangyuan county is located in the eastern part of Qinghai province and is the transition zone of Loess Plateau and Qinghai-Tibet Plateau. While the ecological environment in Huangyuan county is fragile and is mainly characterized as serous soil erosion, frequent natural disasters. It is very important to study the soil erosion. Hudan river basin was selected to study the soil erosion in Huangyuan county. The soil erosion information was extracted from Landsat 5 TM data in 1987, 2000 and 2010. To classify and grade soil erosion was according to the classification standard, Classification Standard for Soil Erosion, issued by the Ministry of Water Resources of the People's Republic of China. The types of soil erosion in the basin were classified as water erosion, freeze-thaw erosion and engineering erosion based on TM imagery, field survey and historical data. Water erosion was the most important part and accounted for more than 90% of the whole area. Weak water erosion increased significantly during the period, mainly distributing in the north of the basin. Slight-degree water erosion increased from 1987 to 2000, while there was a steep reduce during the period from 2000 to 2010. Freeze-thaw erosion distributed mainly in northern areas with high altitude. What Engineering erosion affected were narrow valley areas suitable for human settlements and agricultural production.

  6. Rangeland runoff and soil erosion database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The estimated annual costs of damage caused by soil erosion and excessive sediment in surface waters within the U.S. is approximately $6 billion to $16 billion annually. Historically, information on the types, patterns, causes, spatial location, severity, and extent of land degradation through soil ...

  7. Erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Erosion is the detachment of soil particles and transportation to another location. Wind erosion occurs when wind speed exceeds a critical threshold level, and loose soil particles or soil particles removed by abrasion then move in one of three ways: creep, saltation, and suspension. Erosion by wate...

  8. Models For Soil Erosion In Europe

    NASA Astrophysics Data System (ADS)

    Kirkby, M. J.; Irvine, B.; Gobin, A.; Govers, G.

    2003-04-01

    A model to estimate Soil Erosion risk is being extended, within the PESERA project, for the full range of environments in Europe. The model provides estimates, at 1 km resolution, of the expected mean erosion rates. Data for land use, topographic, soil and climate are used to estimate ground cover, surface crusting, runoff and sediment transport and so forecast the water and sediment delivered to stream channels. The estimates are consistent with finer scale erosion models for flow strips, evaluated at the slope base; and are integrated across the frequency distribution of storm magnitudes. The model is based on a partition of daily precipitation into interception, Hortonian and saturation overland flow, subsurface flow and evapo-transpiration. Hortonian overland flow, which is mainly responsible for soil erosion, is generated with respect to local soil and sub-surface moisture characteristics. Some allowance is also made for snow accumulation and melting. Preliminary model results are available, and forecasts are now being calibrated against runoff plot and small catchment data. 'The model produces a quantitative forecast of soil erosion and vegetation growth, and has the capacity to respond rationally to a range of possible climate or land use scenarios.

  9. Soil erosion survey using remote sensing images

    NASA Astrophysics Data System (ADS)

    Jakab, Gergely; Kertész, Ádám; Madarász, Balázs; Pálinkás, Melinda; Tóth, Adrienn

    2016-04-01

    Soil erosion is one of the most effective soil degradation processes reducing crop production on arable fields significantly. It also leads to serious environmental hazards such as eutrophication, mud and flesh floods. Beyond the processes there is an urgent need to survey and descript the current degree of erosion of arable lands in order to provide adequate land use techniques and mitigate the harmful effects. Surveying soil erosion is a very time consuming process since soil loss and deposition take place next to each other resulting a rather diverse erosion pattern even within a plot. Remote sensing is a possible way to determine the degree of soil erosion without special efforts taken in the field. The application of images can provide high resolution erosion maps of almost any type of arable fields. The method is based on the identification of the origin of the surface soil layer, i.e. whether it represents an originally deeper laying horizon (e.g. B horizon), or the parent material. A case study was carried out on a Cambisol formed on loess parent material. The soil and the parent rock have various reflectance spectra in the visible range, so this strip was used for the investigations. For map creation "training sites" were used in ArcMap environment. The obtained results suggest that the method is highly effective and useful, however, other properties like moisture content and plant cover can limit automated application. In this case new training sites are needed. The study was supported by the National Research, Development and Innovation Office (NKFIH),), project Nr. 108755 and the support is gratefully acknowledged here. G. Jakab was supported by the János Bolyai Fellowship.

  10. Soil erodibility: A comparison between the Jet Erosion Test and the Hole Erosion Test

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The erosion behavior of clay soils is important for many applications within water resources (i.e. earthen spillway erosion, river channel erosion, bank stability, and dam, and levee failures). The objective of this study was to compare soil erodibility results of two different erosion testing devi...

  11. Soil property effects on wind erosion of organic soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (>20%) in half or more of the upper 80 cm. Forty four states have a total of 21 million ha of histosols in the United States. These soils, when intensively cropped, are subject to wind erosion r...

  12. Soil Property Effects on Wind Erosion of Organic Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (>20%) in half or more of the upper 80 cm. Forty four states have a total of 21 million ha of histosols in the United States. These soils, when intensively cropped, are subject to wind erosion r...

  13. Modelling Soil Erosion in the Densu River Basin Using RUSLE and GIS Tools.

    PubMed

    Ashiagbori, G; Forkuo, E K; Laari, P; Aabeyir, R

    2014-07-01

    Soil erosion involves detachment and transport of soil particles from top soil layers, degrading soil quality and reducing the productivity of affected lands. Soil eroded from the upland catchment causes depletion of fertile agricultural land and the resulting sediment deposited at the river networks creates river morphological change and reservoir sedimentation problems. However, land managers and policy makers are more interested in the spatial distribution of soil erosion risk than in absolute values of soil erosion loss. The aim of this paper is to model the spatial distribution of soil erosion in Densu River Basin of Ghana using RUSLE and GIS tools and to use the model to explore the relationship between erosion susceptibility, slope and land use/land cover (LULC) in the Basin. The rainfall map, digital elevation model, soil type map, and land cover map, were input data in the soil erosion model developed. This model was then categorized into four different erosion risk classes. The developed soil erosion map was then overlaid with the slope and LULC maps of the study area to explore their effects on erosion susceptibility of the soil in the Densu River Basin. The Model, predicted 88% of the basin as low erosion risk and 6% as moderate erosion risk, 3% as high erosion risk and 3% as severe risk. The high and severe erosion areas were distributed mainly within the areas of high slope gradient and also sections of the moderate forest LULC class. Also, the areas within the moderate forest LULC class found to have high erosion risk, had an intersecting high erodibility soil group. PMID:26563073

  14. Quantifying accelerated soil erosion through ecological site-based assessments of wind and water erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This work explores how organising soil erosion assessments using established groupings of similar soils (ecological sites) can inform systems for managing accelerated soil erosion. We evaluated aeolian sediment transport and fluvial erosion rates for five ecological sites in southern New Mexico, USA...

  15. Experiments for understanding soil erosion processes

    NASA Astrophysics Data System (ADS)

    Seeger, Manuel

    2015-04-01

    Soil erosion processes are usually quantified by observation and measurement of their related forms. Rill, and gullies, moulds or sediment sinks are often used to estimate the soil loss. These forms are generally related directly to different types of processes, thus are also used to identify the dominant processes on a certain type of land-use. Nevertheless, the direct observation of erosion processes is constrained by their temporal and spatial erratic occurrence. As a consequence, the process understanding is generally deduced by analogies. Another possibility is to reproduce processes in experiments in both, the lab and in the field. Laboratory experiments are implemented when we want to have full control over all parameters we think are relevant for the process in our focus. So are very useful for identification of parameters influencing processes and their intensities, but also as physical models of the processes and process interactions in our focus. Therefore, we can use them to verify our concepts, and to define relevant parameters. Field experiments generally only simulate with controlled driving forces, this is the rain or the runoff, but dealing with the uncertainty of our study object, the soil. This enables two things: 1) similar as with lab experiments, we are able to identify processes and process interactions and so, to get a deeper understanding of soil erosion; 2) experiments are suitable for providing data about singular processes in the field and thus, to provide data suitable for model parametrisation and calibration. These may be quantitative data about erodibility or soil resistance, sediment detachment or transport. The Physical Geography Group at Trier University has a long lasting experience in the application of experiments in soil erosion research in the field, and has become lead in the further development conception and of devices and procedures to investigate splash detachment and initial transport of soil particles by wind and water

  16. Soil aggregation, erodibility, and erosion rates in mountain soils (NW Alps, Italy)

    NASA Astrophysics Data System (ADS)

    Stanchi, S.; Falsone, G.; Bonifacio, E.

    2015-04-01

    Erosion is a relevant soil degradation factor in mountain agrosilvopastoral ecosystems that can be enhanced by the abandonment of agricultural land and pastures left to natural evolution. The on-site and off-site consequences of soil erosion at the catchment and landscape scale are particularly relevant and may affect settlements at the interface with mountain ecosystems. RUSLE (Revised Universal Soil Loss Equation) estimates of soil erosion consider, among others, the soil erodibility factor (K), which depends on properties involved in structure and aggregation. A relationship between soil erodibility and aggregation should therefore be expected. However, erosion may limit the development of soil structure; hence aggregates should not only be related to erodibility but also partially mirror soil erosion rates. The aim of the research was to evaluate the agreement between aggregate stability and erosion-related variables and to discuss the possible reasons for discrepancies in the two kinds of land use considered (forest and pasture). Topsoil horizons were sampled in a mountain catchment under two vegetation covers (pasture vs. forest) and analyzed for total organic carbon, total extractable carbon, pH, and texture. Soil erodibility was computed, RUSLE erosion rate was estimated, and aggregate stability was determined by wet sieving. Aggregation and RUSLE-related parameters for the two vegetation covers were investigated through statistical tests such as ANOVA, correlation, and regression. Soil erodibility was in agreement with the aggregate stability parameters; i.e., the most erodible soils in terms of K values also displayed weaker aggregation. Despite this general observation, when estimating K from aggregate losses the ANOVA conducted on the regression residuals showed land-use-dependent trends (negative average residuals for forest soils, positive for pastures). Therefore, soil aggregation seemed to mirror the actual topsoil conditions better than soil

  17. A legacy of past soil erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This brief (775 word) article, written for a non-technical audience, describes how soil erosion during the early decades of agriculture in Iowa contributed sediment that accumulated in local stream and river valleys. A Grant Wood painting titled 'Young Corn' is used to illustrate how early cropping ...

  18. Predicting soil erosion for alternative land uses.

    PubMed

    Wang, Erda; Xin, Chang; Williams, Jimmy R; Xu, Cheng

    2006-01-01

    The APEX (Agricultural Policy-Environmental eXtender) model developed in the United States was calibrated for northwestern China's conditions. The model was then used to investigate soil erosion effects associated with alternative land uses at the ZFG (Zi-Fang-Gully) watershed in northwestern China. The results indicated that the APEX model could be calibrated reasonably well (+/-15% errors) to fit those areas with >50% slope within the watershed. Factors being considered during calibration include runoff, RUSLE (Revised Universal Soil Loss Equation) slope length and steepness factor, channel capacity flow rate, floodplain saturated hydraulic conductivity, and RUSLE C factor coefficient. No changes were made in the APEX computer code. Predictions suggest that reforestation is the best practice among the eight alternative land uses (the status quo, all grass, all grain, all grazing, all forest, half tree and half grass, 70% tree and 30% grain, and construction of a reservoir) for control of water runoff and soil erosion. Construction of a reservoir is the most effective strategy for controlling sediment yield although it does nothing to control upland erosion. For every 1 Mg of crop yield, 11 Mg of soil were lost during the 30-yr simulation period, suggesting that expanding land use for food production should not be encouraged on the ZFG watershed. Grass species are less effective than trees in controlling runoff and erosion on steep slopes because trees generally have deeper and more stable root systems. PMID:16455846

  19. Soil erosion dynamics through multiple rainfall events

    NASA Astrophysics Data System (ADS)

    Jomaa, S.; Barry, D. A.; Brovelli, A.; Heng, B. P.; Parlange, J.

    2012-12-01

    The dynamics of soil erosion during repeated rainfall events was studied, in particular focusing on the effect of initial soil characteristics and surface shielding by rock fragments. A sequence of four 2-h erosive events (named H7- E1, E2, and E3, respectively) separated by 22 h of air drying was performed using a 6-m long laboratory rainfall simulator and erosion flume. A loamy soil was used in all experiments. The surface was hand cultivated before the first event. Rainfall intensities of 28, 74, 74 and 28 mm h-1 were considered. The erosion flume was divided into two identical 1-m wide sections, one of which was covered with rock fragments. Results showed that steady-state behavior is mainly controlled by the rainfall intensity. Soil initial conditions, in particular whether steady state was reached during the previous event, control the sediment yields during the initial transient phase of the erosive event. If quasi-steady behavior was reached for a particular sediment size class, that class's effluent concentration peaked rapidly in the next rainfall event, then declined gradually to its steady-state value. In contrast, if the sediment concentrations were still varying at the end of a rainfall event, the subsequent event produced effluent concentrations that increased gradually to steady state. The surface rock fragments reduced the time needed to achieve the steady state, compared to bare soil conditions. The Hairsine and Rose erosion model was adopted to analyze the measured sediment delivery. A satisfactory comparison was observed for the two experiments in which the soil was only slightly modified by raindrop impact (H7-E3 and H7-E4). On the contrary, the model could not predict accurately the erosion yields of the first two rainfall events (H7-E1 and H7-E2), during which the soil surface was heavily compacted and a surface seal developed. Furthermore, the model could not reproduce in detail the sediment concentrations of the individual size classes

  20. Boreal forest soil erosion and soil-atmosphere carbon exchange

    NASA Astrophysics Data System (ADS)

    Billings, S. A.; Harden, J. W.; O'Donnell, J.; Sierra, C. A.

    2013-12-01

    Erosion may become an increasingly important agent of change in boreal systems with climate warming, due to enhanced ice wedge degradation and increases in the frequency and intensity of stand-replacing fires. Ice wedge degradation can induce ground surface subsidence and lateral movement of mineral soil downslope, and fire can result in the loss of O horizons and live roots, with associated increases in wind- and water-promoted erosion until vegetation re-establishment. It is well-established that soil erosion can induce significant atmospheric carbon (C) source and sink terms, with the strength of these terms dependent on the fate of eroded soil organic carbon (SOC) and the extent to which SOC oxidation and production characteristics change with erosion. In spite of the large SOC stocks in the boreal system and the high probability that boreal soil profiles will experience enhanced erosion in the coming decades, no one has estimated the influence of boreal erosion on the atmospheric C budget, a phenomenon that can serve as a positive or negative feedback to climate. We employed an interactive erosion model that permits the user to define 1) profile characteristics, 2) the erosion rate, and 3) the extent to which each soil layer at an eroding site retains its pre-erosion SOC oxidation and production rates (nox and nprod=0, respectively) vs. adopts the oxidation and production rates of previous, non-eroded soil layers (nox and nprod=1, respectively). We parameterized the model using soil profile characteristics observed at a recently burned site in interior Alaska (Hess Creek), defining SOC content and turnover times. We computed the degree to which post-burn erosion of mineral soil generates an atmospheric C sink or source while varying erosion rates and assigning multiple values of nox and nprod between 0 and 1, providing insight into the influence of erosion rate, SOC oxidation, and SOC production on C dynamics in this and similar profiles. Varying nox and nprod

  1. Historic Assessment of Agricultural Impacts on Soil and Soil Organic Carbon Erosion in an Ohio Watershed

    SciTech Connect

    Hao, Yueli; Lal, Rattan; Izaurralde, R Cesar C. ); Ritchie, Jerry; Owens, Lloyd; Hothem, Daniel

    2002-02-01

    Agricultural management affects soil and soil organic carbon (SOC) erosion. The effect was assessed for a watershed (o.79 ha, 10% slope steepness, 132 m slope length) at the North Appalachian Experimental Watershed research station near Coshocton, Ohio, from 1951 to 1998

  2. Environmental stochasticity controls soil erosion variability

    PubMed Central

    Kim, Jongho; Ivanov, Valeriy Y.; Fatichi, Simone

    2016-01-01

    Understanding soil erosion by water is essential for a range of research areas but the predictive skill of prognostic models has been repeatedly questioned because of scale limitations of empirical data and the high variability of soil loss across space and time scales. Improved understanding of the underlying processes and their interactions are needed to infer scaling properties of soil loss and better inform predictive methods. This study uses data from multiple environments to highlight temporal-scale dependency of soil loss: erosion variability decreases at larger scales but the reduction rate varies with environment. The reduction of variability of the geomorphic response is attributed to a ‘compensation effect’: temporal alternation of events that exhibit either source-limited or transport-limited regimes. The rate of reduction is related to environment stochasticity and a novel index is derived to reflect the level of variability of intra- and inter-event hydrometeorologic conditions. A higher stochasticity index implies a larger reduction of soil loss variability (enhanced predictability at the aggregated temporal scales) with respect to the mean hydrologic forcing, offering a promising indicator for estimating the degree of uncertainty of erosion assessments. PMID:26925542

  3. Environmental stochasticity controls soil erosion variability.

    PubMed

    Kim, Jongho; Ivanov, Valeriy Y; Fatichi, Simone

    2016-01-01

    Understanding soil erosion by water is essential for a range of research areas but the predictive skill of prognostic models has been repeatedly questioned because of scale limitations of empirical data and the high variability of soil loss across space and time scales. Improved understanding of the underlying processes and their interactions are needed to infer scaling properties of soil loss and better inform predictive methods. This study uses data from multiple environments to highlight temporal-scale dependency of soil loss: erosion variability decreases at larger scales but the reduction rate varies with environment. The reduction of variability of the geomorphic response is attributed to a 'compensation effect': temporal alternation of events that exhibit either source-limited or transport-limited regimes. The rate of reduction is related to environment stochasticity and a novel index is derived to reflect the level of variability of intra- and inter-event hydrometeorologic conditions. A higher stochasticity index implies a larger reduction of soil loss variability (enhanced predictability at the aggregated temporal scales) with respect to the mean hydrologic forcing, offering a promising indicator for estimating the degree of uncertainty of erosion assessments. PMID:26925542

  4. Environmental stochasticity controls soil erosion variability

    NASA Astrophysics Data System (ADS)

    Kim, Jongho; Ivanov, Valeriy Y.; Fatichi, Simone

    2016-03-01

    Understanding soil erosion by water is essential for a range of research areas but the predictive skill of prognostic models has been repeatedly questioned because of scale limitations of empirical data and the high variability of soil loss across space and time scales. Improved understanding of the underlying processes and their interactions are needed to infer scaling properties of soil loss and better inform predictive methods. This study uses data from multiple environments to highlight temporal-scale dependency of soil loss: erosion variability decreases at larger scales but the reduction rate varies with environment. The reduction of variability of the geomorphic response is attributed to a ‘compensation effect’: temporal alternation of events that exhibit either source-limited or transport-limited regimes. The rate of reduction is related to environment stochasticity and a novel index is derived to reflect the level of variability of intra- and inter-event hydrometeorologic conditions. A higher stochasticity index implies a larger reduction of soil loss variability (enhanced predictability at the aggregated temporal scales) with respect to the mean hydrologic forcing, offering a promising indicator for estimating the degree of uncertainty of erosion assessments.

  5. Potential for monitoring soil erosion features and soil erosion modeling components from remotely sensed data

    NASA Technical Reports Server (NTRS)

    Langran, K. J.

    1983-01-01

    Accurate estimates of soil erosion and its effects on soil productivity are essential in agricultural decision making and planning from the field scale to the national level. Erosion models have been primarily developed for designing erosion control systems, predicting sediment yield for reservoir design, predicting sediment transport, and simulating water quality. New models proposed are more comprehensive in that the necessary components (hydrology, erosion-sedimentation, nutrient cycling, tillage, etc.) are linked in a model appropriate for studying the erosion-productivity problem. Recent developments in remote sensing systems, such as Landsat Thematic Mapper, Shuttle Imaging Radar (SIR-B), etc., can contribute significantly to the future development and operational use of these models.

  6. Effects of gully erosion and gully filling on soil depth and crop production in the black soil region, northeast China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gully erosion has affected the crop yield in the black soil region of China and become a potential threat to Chan’s food security. This paper aimed to quantify the effects of gully erosion on soil depth and soybean yield. An ephemeral gully (74 m) and a classic gully (52 m) connected at the gully’s ...

  7. Terrace effects on soil erosion processes in a watershed of the loess plateau

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Terraces in crop fields are one of the most important soil and water conservation measures that affect runoff and erosion processes in a watershed. In this paper, terrace effects on soil erosion and sediment transport in the upstream and middle sections of the Weihe River basin in the Loess Plateau ...

  8. SOIL AND NUTRIENT EROSION RISK IN ORGANIC AND CONVENTIONAL CROPPING SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic farming, which is growing in popularity, has been proposed as a sustainable alternative to conventional farming practices. However, it is not known how organic farming systems affect soil erosion risk and sediment-bound nutrient transport. Our objectives were to compare soil erosion risk and...

  9. Soil Erosion as a stochastic process

    NASA Astrophysics Data System (ADS)

    Casper, Markus C.

    2015-04-01

    The main tools to provide estimations concerning risk and amount of erosion are different types of soil erosion models: on the one hand, there are empirically based model concepts on the other hand there are more physically based or process based models. However, both types of models have substantial weak points. All empirical model concepts are only capable of providing rough estimates over larger temporal and spatial scales, they do not account for many driving factors that are in the scope of scenario related analysis. In addition, the physically based models contain important empirical parts and hence, the demand for universality and transferability is not given. As a common feature, we find, that all models rely on parameters and input variables, which are to certain, extend spatially and temporally averaged. A central question is whether the apparent heterogeneity of soil properties or the random nature of driving forces needs to be better considered in our modelling concepts. Traditionally, researchers have attempted to remove spatial and temporal variability through homogenization. However, homogenization has been achieved through physical manipulation of the system, or by statistical averaging procedures. The price for obtaining this homogenized (average) model concepts of soils and soil related processes has often been a failure to recognize the profound importance of heterogeneity in many of the properties and processes that we study. Especially soil infiltrability and the resistance (also called "critical shear stress" or "critical stream power") are the most important empirical factors of physically based erosion models. The erosion resistance is theoretically a substrate specific parameter, but in reality, the threshold where soil erosion begins is determined experimentally. The soil infiltrability is often calculated with empirical relationships (e.g. based on grain size distribution). Consequently, to better fit reality, this value needs to be

  10. Soil erosion and surface runoff model SMODERP

    NASA Astrophysics Data System (ADS)

    Kavka, P.; Vrana, K.; Dostal, T.

    2012-04-01

    This contribution presents a software tool for calculation and prediction of soil erosion and surface runoff from agricultural lands. There is no universal tool to properly describe the origin and the processes related to the surface runoff and sediment transport in different scales. For a design of any technical erosion control measures, that are used to interrupt the surface runoff, it is necessary to identify basic outflow characteristics (discharge, flow volume). Numerical model SMODERP was developed for determination of these characteristics. The model is being developed at the Department of Irrigation, Drainage and Landscape Engineering , Civil Engineering Faculty, CTU in Prague. SMODERP is physically based one-dimensional episodic model that includes the processes of infiltration, surface retention, surface roughness and vegetation impact on runoff. The model has been substantially upgraded and tested in last few years. Especially runoff parameters, time and spatial discretisation were recalibrated and validated. Runoff parameters were recalibrated on the set of forty measurements performed on the laboratory rainfall simulator on five soil types. The parameters were designed for five soil types categories according to content of particles with size up to 0.01 mm (Novak soil classification). The precipitation episodes can be chosen from the attached catalogue or can be designed by a user. We also present how the input data can be obtained based on available resources (soil maps and data, land use, terrain models, field research, etc.) and how can be used in the assessment erosion risk and in designing of erosion control measures. The model is meant to be used not only for the research purposes, but mainly for the engineering practice. We present the new version of the model that includes a new user friendly graphical interface. The research has been supported by the research grants SGS SGS11/148/OHK1/3T/11 "Experimental Research on Rainfall-runoff and Erosion

  11. Quantification Of Erosion Rates Of Agriculturally Used Soils By Artificial

    NASA Astrophysics Data System (ADS)

    Jha, Abhinand

    2010-05-01

    0.0.1 1. Introduction to soil erosion measurement by radionuclides Soil erosion by water, wind and tillage affects both agriculture and the natural environment. Studying this phenomenon would be one of the advancements in science. Soil erosion occurs worldwide and since the last two decades it has been a main topic of discussion all over the world. The use of environmental radionuclides such as 90Sr, 137Cs to study medium term soil erosion (40 yrs) started in the early 1990's. Using these new techniques better knowledge about erosion can be gained and this knowledge can be implemented for erosion risk management. The erosion and sedimentation study by using man-made and natural radioisotopes is a key technique, which has developed over the past 30 years. Fallout 137Cs and Cosmogenic 7Be are radionuclides that have been used to provide independent measurements of soil-erosion and sediment-deposition rates and patterns [1] [2] [3] [4]. Erosion measurements using radionuclides 137Cs, 7Be Caesium-137 from atmospheric nuclear-weapons tests in the 1950s and 1960s (Fig.1) is a unique tracer of erosion and sedimentation, since there are no natural sources of 137Cs. Unique events such as the Chernobyl accident in April 1986 caused regional dispersal of 137Cs that affects the total global deposition budget. This yearly pattern of fallout can be used to develop a chronology of deposition horizons in lakes, reservoirs, and floodplains. 137Cs can be easily measured by gamma spectroscopy. Using 137Cs is a fast and cheap method to study erosion-deposition processes compared to the traditional methods like silt bags. PIC Figure 1: Global 137Cs fallout (Modified from SAAS Bulletin 353, Part E, DDR, 1986) When 137Cs, 7Be reach the soil surface by wet and dry deposition, they are quickly and strongly adsorbed by ion exchange and are essentially non exchangeable in most environments. Each radionuclide is distributed differently in the soil because of differences in half-lives (30 yrs

  12. Pattern geomorphologic analysis for soil erosion study

    NASA Astrophysics Data System (ADS)

    Selmaoui, Nazha; Rouet, Isabelle; Mahot, Mélanie

    2009-01-01

    The geologist try to understand relationship between soil erosion observed and natural landscape structure. Erosion can effectively appears in the vicinity of linear or planar structures of soil (lines, faults or materials change). Once eroded areas are mapped, an inventory of relief linear shapes is done. The crossing geomorphological analysis with other environmental parameters allows to predict the becoming eroded areas. Lineaments detection is usually made by photointerpretation. DEM (Digital Elevation Model) visual analysis is another alternative but not sufficient, so it uses the derived models from DEM called hillshade images. The DEM is lighted up by a virtual source with a direction and height incidence. A good study require a complete lightings visual interpretation which is very slow and subjective. This paper propose an automatic process that help geologist to detect and analyse the geomorphological structures present in the landscape by using image analysis methods. This study focus on lines and catchments basins structures. First a new watershed and catchments basins segmentation method is developed it defines an attractive structure between pixels (based on path of steepest slope). After these lines are automatically extracted by Hough transform and their preferential direction is analysed by a technique called directions rose. Some results are given on DEM and Hillshade images for a particular areas of the main New Caledonia island where soil erosion is a serious problem mainly due to tropical weather (violent rains) and human activities (mining, bush fire) on the weathered rocks (laterites) in mountain.

  13. Acoustic measurements of soil pipeflow and internal erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Internal erosion of soil pipes can lead to embankment failures, landslides, and gully erosion therefore non-intrusive methods are needed to detect and monitor soil pipeflow and the resulting internal erosion. This paper presents a laboratory study using both active and passive acoustic techniques to...

  14. Acoustic measurements of soil-pipeflow and internal erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Internal erosion of soil pipes can lead to embankment failures, landslides, and gully erosion. Therefore, non-intrusive methods are needed to detect and monitor soil pipeflow and the resulting internal erosion. This paper presents a laboratory study using both active and passive acoustic techniques ...

  15. Erosion of soil organic carbon: implications for carbon sequestration

    USGS Publications Warehouse

    Van Oost, Kristof; Van Hemelryck, Hendrik; Harden, Jennifer W.

    2009-01-01

    Agricultural activities have substantially increased rates of soil erosion and deposition, and these processes have a significant impact on carbon (C) mineralization and burial. Here, we present a synthesis of erosion effects on carbon dynamics and discuss the implications of soil erosion for carbon sequestration strategies. We demonstrate that for a range of data-based parameters from the literature, soil erosion results in increased C storage onto land, an effect that is heterogeneous on the landscape and is variable on various timescales. We argue that the magnitude of the erosion term and soil carbon residence time, both strongly influenced by soil management, largely control the strength of the erosion-induced sink. In order to evaluate fully the effects of soil management strategies that promote carbon sequestration, a full carbon account must be made that considers the impact of erosion-enhanced disequilibrium between carbon inputs and decomposition, including effects on net primary productivity and decomposition rates.

  16. Measurement of soil water erosion in Africa: the potential support provided by nuclear techniques

    NASA Astrophysics Data System (ADS)

    Mabit, Lionel

    2010-05-01

    Conservation of soil and water resources has become a major agronomic and environmental concern. Degradation phenomena, such as erosion, desertification and salinization affect 65% of soils worldwide. Soil degradation is currently affecting 1.9 billion hectares and is increasing at a rate of 5 to 7 million hectares each year. Almost 50% of 133 million ha degraded soils by overexploitation are located in Africa. The degradation of arable lands affects especially arid areas with poor vegetation cover and tropical areas with high intensity rainfall. Water erosion is by far the most common type of land degradation in Africa. Accelerated erosion decreases soil productivity, increases sedimentation and is related to environmental pollution problems in agro-ecosystems. To control soil erosion there is a need to assess the impact of major land use and the effectiveness of specific soil conservation technologies using various approaches. Effective erosion control starts with the knowledge of soil erosion rates and mechanisms. In Africa, various research projects on water erosion have been implemented involving different conventional techniques such as remote sensing, morphometric investigation, sediment transport models and sediment loading measurements, runoff plots and rainfall erosivity measurements. However, only limited quantitative data on erosion and sedimentation magnitude under African agroenvironmental condition are available. Traditional monitoring and modeling techniques for soil water erosion require many parameters and years of measurements of (inter-annual and mid-term) climatic variability and cropping practices. Conventional erosion and sedimentation methods are limited to provide mid-term trends in soil erosion, however fallout radionuclides (FRN) - e.g. 137-Cs, 210-Pb and 7-Be - have proven to be very powerful tools to trace soil erosion and sedimentation within the landscape from plot to basin scale. FRN techniques allow the estimation of short and

  17. Evaluation of radiocaesium wash-off by soil erosion from various land uses using USLE plots.

    PubMed

    Yoshimura, Kazuya; Onda, Yuichi; Kato, Hiroaki

    2015-01-01

    Radiocaesium wash-off associated with soil erosion in different land use was monitored using USLE plots in Kawamata, Fukushima Prefecture, Japan after the Fukushima Dai-ichi Nuclear Power Plant accident. Parameters and factors relating to soil erosion and (137)Cs concentration in the eroded soil were evaluated based on the field monitoring and presented. The erosion of fine soil, which is defined as the fraction of soil overflowed along with discharged water from a sediment-trap tank, constituted a large proportion of the discharged radiocaesium. This indicated that the quantitative monitoring of fine soil erosion is greatly important for the accurate evaluation of radiocaesium wash-off. An exponential relationship was found between vegetation cover and the amount of eroded soil. Moreover, the radiocaesium concentrations in the discharged soil were greatly affected by the land use. These results indicate that radiocaesium wash-off related to vegetation cover and land use is crucially important in modelling radiocaesium migration. PMID:25113169

  18. Preliminary assessment of soil erosion impact during forest restoration process

    NASA Astrophysics Data System (ADS)

    Lai, Yen-Jen; Chang, Cheng-Sheng; Tsao, Tsung-Ming; Wey, Tsong-Huei; Chiang, Po-Neng; Wang, Ya-Nan

    2014-05-01

    Taiwan has a fragile geology and steep terrain. The 921 earthquake, Typhoon Toraji, Typhoon Morakot, and the exploitation and use of the woodland by local residents have severely damaged the landscape and posed more severe challenges to the montane ecosystem. A land conservation project has been implemented by the Experimental Forest of National Taiwan University which reclaimed approximately 1,500 hectares of leased woodland from 2008 to 2010, primarily used to grow bamboo, tea trees, betel nut, fruit, and vegetable and about 1,298 hectares have been reforested. The process of forest restoration involves clear cutting, soil preparation and a six-year weeding and tending period which may affect the amount of soil erosion dramatically. This study tried to assess the impact of forest restoration from the perspective of soil erosion through leased-land recovery periods and would like to benefit the practical implementation of reforestation in the future. A new plantation reforested in the early 2013 and a nearby 29-year-old mature forest were chosen as experimental and comparison sites. A self-designed weir was set up in a small watershed of each site for the runoff and sediment yield observation. According to the observed results from May to August 2013, a raining season in Taiwan, the runoff and erosion would not as high as we expected, because the in-situ soil texture of both sites is sandy loam to sandy with high percentage of coarse fragment which increased the infiltration. There were around 200 kg to 250 kg of wet sand/soil yielded in mature forest during the hit of Typhoon Soulik while the rest of the time only suspended material be yielded at both sites. To further investigate the influence of the six-year weeding and tending period, long term observations are needed for a more completed assessment of soil erosion impact.

  19. Tree species and functional traits but not species richness affect interrill erosion processes in young subtropical forests

    NASA Astrophysics Data System (ADS)

    Seitz, S.; Goebes, P.; Song, Z.; Bruelheide, H.; Härdtle, W.; Kühn, P.; Li, Y.; Scholten, T.

    2016-01-01

    Soil erosion is seriously threatening ecosystem functioning in many parts of the world. In this context, it is assumed that tree species richness and functional diversity of tree communities can play a critical role in improving ecosystem services such as erosion control. An experiment with 170 micro-scale run-off plots was conducted to investigate the influence of tree species and tree species richness as well as functional traits on interrill erosion in a young forest ecosystem. An interrill erosion rate of 47.5 Mg ha-1 a-1 was calculated. This study provided evidence that different tree species affect interrill erosion differently, while tree species richness did not affect interrill erosion in young forest stands. Thus, different tree morphologies have to be considered, when assessing soil erosion under forest. High crown cover and leaf area index reduced interrill erosion in initial forest ecosystems, whereas rising tree height increased it. Even if a leaf litter cover was not present, the remaining soil surface cover by stones and biological soil crusts was the most important driver for soil erosion control. Furthermore, soil organic matter had a decreasing influence on interrill erosion. Long-term monitoring of soil erosion under closing tree canopies is necessary, and a wide range of functional tree traits should be considered in future research.

  20. How does slope form affect erosion in CATFLOW-SED?

    NASA Astrophysics Data System (ADS)

    Gabelmann, Petra; Wienhöfer, Jan; Zehe, Erwin

    2016-04-01

    Erosion is a severe environmental problem in agro-ecosystems with highly erodible loess soils. It is controlled by various factors, e.g. rainfall intensity, initial wetness conditions, soil type, land use and tillage practice. Furthermore slope form and gradient have been shown to influence erosion amounts to a large extent. Within the last fifty years, various erosion models have been developed to describe the erosion process, estimate erosion amounts and identify erosion-prone areas. These models differ in terms of complexity, the processes which are considered, and the data required for model calibration and they can be categorised into empirical or statistical, conceptual, and physically-based models. CATFLOW-SED is a process-based hydrology and erosion model that can operate on catchment and hillslope scales. Soil water dynamics are described by the Richards equation including effective approaches for preferential flow. Evapotranspiration is simulated using an approach based on the Penman-Monteith equation. The model simulates overland flow using the diffusion wave equation. Soil detachment is related to the attacking forces of rainfall and overland flow, and the erosion resistance of soil. Sediment transport capacity and sediment deposition are related to overland flow velocity using the equation of Engelund and Hansen and the sinking velocity of grain sizes respectively. We performed a study to analyse the erosion process on different virtual hillslopes, with varying slope gradient and slope form, using the CATFLOW-SED model. We explored the role of landform on erosion and sedimentation, particularly we look for forms that either maximise or minimise erosion. Results indicate the importance to performing the process implementation within physically meaningful limits and choose appropriate model parameters respectively.

  1. An empirical approach to estimate soil erosion risk in Spain.

    PubMed

    Martín-Fernández, Luis; Martínez-Núñez, Margarita

    2011-08-01

    Soil erosion is one of the most important factors in land degradation and influences desertification worldwide. In 2001, the Spanish Ministry of the Environment launched the 'National Inventory of Soil Erosion (INES) 2002-2012' to study the process of soil erosion in Spain. The aim of the current article is to assess the usefulness of this National Inventory as an instrument of control, measurement and monitoring of soil erosion in Spain. The methodology and main features of this National Inventory are described in detail. The results achieved as of the end of May 2010 are presented, together with an explanation of the utility of the Inventory as a tool for planning forest hydrologic restoration, soil protection, erosion control, and protection against desertification. Finally, the authors make a comparative analysis of similar initiatives for assessing soil erosion in other countries at the national and European levels. PMID:21621247

  2. Challenges in soil erosion research and prediction model development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantification of soil erosion has been traditionally considered as a surface hydrologic process with equations for soil detachment and sediment transport derived from the mechanics and hydraulics of the rainfall and surface flow. Under the current erosion modeling framework, the soil has a constant...

  3. Improving Soil Erosion Predictions with 21st Century Data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a result of 1930’s Dust Bowl, the U.S. initiated soil erosion and land conservation programs. The Universal Soil Loss (USLE) was one result of this effort and has remained one of the most widely used equations for soil erosion prediction world-wide. This empirical relationship has been incorpor...

  4. Model isothermal internal erosion of soil

    NASA Astrophysics Data System (ADS)

    Papin, A. A.; Sibin, A. N.

    2016-06-01

    The process of internal erosion in a three-phase saturated soil is studied. The problem is described by the equations of mass conservation, Darcy's law and the equation of capillary pressure. The original system of equations is reduced to a system of two equations for porosity and water saturation. In general, the equation of water saturation is degenerate. The degenerate problem in a one-dimensional domain and one special case of the problem in a two-dimensional domain are solved numerically using a finite-difference method. Existence and uniqueness of a classical solution of a nondegenerate problem is proved.

  5. LAPSUS: soil erosion - landscape evolution model

    NASA Astrophysics Data System (ADS)

    van Gorp, Wouter; Temme, Arnaud; Schoorl, Jeroen

    2015-04-01

    LAPSUS is a soil erosion - landscape evolution model which is capable of simulating landscape evolution of a gridded DEM by using multiple water, mass movement and human driven processes on multiple temporal and spatial scales. It is able to deal with a variety of human landscape interventions such as landuse management and tillage and it can model their interactions with natural processes. The complex spatially explicit feedbacks the model simulates demonstrate the importance of spatial interaction of human activity and erosion deposition patterns. In addition LAPSUS can model shallow landsliding, slope collapse, creep, solifluction, biological and frost weathering, fluvial behaviour. Furthermore, an algorithm to deal with natural depressions has been added and event-based modelling with an improved infiltration description and dust deposition has been pursued. LAPSUS has been used for case studies in many parts of the world and is continuously developing and expanding. it is now available for third-party and educational use. It has a comprehensive user interface and it is accompanied by a manual and exercises. The LAPSUS model is highly suitable to quantify and understand catchment-scale erosion processes. More information and a download link is available on www.lapsusmodel.nl.

  6. Towards a national-scale understanding of soil erosion in the UK: Building a national soil erosion database

    NASA Astrophysics Data System (ADS)

    Benaud, Pia; Carvalho, Jason; Truckell, Ian; Rickson, Jane; Anderson, Karen; Quine, Timothy; Brazier, Richard

    2015-04-01

    The United Kingdom has a rich dataset of soil erosion observations, which have been collected using a wide range of methodologies, across various spatial and temporal scales. Yet, whilst observations of soil erosion have been carried out along-side agricultural development and intensification, understanding whether or not the UK has a soil erosion problem remains a question to be answered. Furthermore, although good reviews of existing soil erosion rates exist, there isn't a single resource that brings all of this work together. The following work seeks remedy this situation through collating all available, UK-based, soil erosion datasets into a spatially explicit database, describing soil erosion at the national scale. Soil erosion occurs through a complex series of processes, consequently, capturing the full extent of soil erosion requires utilising a suite of techniques across varying spatial and temporal scales, and a wide range of soil types and land management practices. However, preliminary analysis of the geodatabase has highlighted the ad hoc and biased nature of previous soil erosion studies. Exploring the spatial distribution of the datasets has identified a general trend towards conducting erosion studies at locations known to erode. Furthermore, many of the studies use a single research method and are thus unable to capture all erosion processes or pathways. For example, whilst volumetric surveys can quantify soil loss via large rills and gullies, such methods cannot quantify the less-visible, diffuse erosion processes due to sheetwash, wind or tillage (for example). Collating and visualising all UK-based soil erosion datasets has been a useful exercise, however, it has highlighted many shortfalls within existing soil erosion research. The database, therefore, cannot be used to make an unbiased assessment of UK erosion rates. As such, there is a strong argument for a replicable and robust national soil erosion monitoring program to be carried out along

  7. Sustainable agriculture, soil management and erosion from prehistoric times to 2100

    NASA Astrophysics Data System (ADS)

    Vanwalleghem, Tom; Gómez, Jose Alfonso; Infante Amate, Juan; González Molina, Manuel; Fernández, David Soto; Guzmán, Gema; Vanderlinden, Karl; Laguna, Ana; Giráldez, Juan Vicente

    2015-04-01

    The rational use of soil requires the selection of management practices to take profit of the beneficial functions of plant growth, water and nutrient storage, and pollutants removal by filtering and decomposition without altering its properties. However, the first evidence of important and widespread erosion peaks can generally be found with the arrival of the first farmers all over the world. In areas with a long land-use history such as the Mediterranean, clear signs indicating the advanced degradation status of the landscape, such as heavily truncated soils, are visible throughout. Soil conservation practices are then aimed at reducing erosion to geological rates, in equilibrium with long-term soil formation rates, while maximizing agricultural production. The adoption of such practices in most areas of the world are as old as the earliest soil erosion episodes themselves. This work firstly reviews historical evidence linking soil management and soil erosion intensity, with examples from N Europe and the Mediterranean. In particular, work by the authors in olive orchards will be presented that shows how significant variations in soil erosion rates between could be linked to the historical soil management. The potential of historical documents for calibrating a soil erosion model is shown as the model, in this case RUSLE-based and combining tillage and water erosion, adequately represents the measured erosion rate dynamics. Secondly, results from present-day, long-term farm experiments in the EU are reviewed to evaluate the effect of different soil management practices on physical soil properties, such as bulk density, penetration resistance, aggregate stability, runoff coefficient or sediment yield. Finally, we reflect upon model and field data that indicate how future global climate change is expected to affect soil management and erosion and how the examples used above hold clues about sustainable historical management practices that can be used successfully

  8. Updating Soil Surface Conditions During Wind Erosion Events Using the Wind Erosion Prediction System (WEPS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During significant wind erosion events the soil surface is continually modified, however, erosion models rarely account for these changes. The objectives of this work are to provide an overview of the WEPS soil surface update methodology and demonstrate that by periodic surface updating during even...

  9. Updating soil surface conditions during wind erosion events using the Wind Erosion Prediction System (WEPS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During significant wind erosion events the soil surface is continually modified. However, erosion models rarely account for these changes. The objective of this work is to demonstrate that physically-based field-scale models can improve their accuracy by periodically updating soil surface conditio...

  10. Updating soil surface conditions during wind erosion events using the Wind Erosion Prediction System (WEPS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During significant wind erosion events the soil surface is continually modified, however, erosion models rarely account for these changes. The objectives of this work are to provide an overview of the WEPS soil surface update methodology and demonstrate that by periodic surface updating during even...

  11. How operating and environmental conditions affect erosion

    SciTech Connect

    McLaury, B.S.; Shirazi, S.A.; Shadley, J.R.; Rybicki, E.F.

    1999-11-01

    Sand in producing wells (both oil and gas) can result in severe erosion even resulting in failure. This work investigates the effect of a variety of parameters such as diameter, flow velocity, particle size, and fluid properties on the severity of erosion for an elbow. The elbow is selected since it redirects the flow and experiences erosion from the impact of sand particles that do no follow the streamlines of the flow and impinge the pipe wall. A model previously developed for single-phase flow is presented and extended in this work for use with multiphase flow. Results for the maximum penetration rate in an elbow are examined for many parameters in both single-phase and multiphase flow. By assuming an allowable penetration rate, the erosion prediction model can also be used to determine the threshold velocity that would result in this penetration rate. The threshold erosional velocity curves are also generated for the multiphase flow cases.

  12. Advances in soil erosion research: processes, measurement, and modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion by the environmental agents of water and wind is a continuing global menace that threatens the agricultural base that sustains our civilization. Members of ASABE have been at the forefront of research to understand erosion processes, measure erosion and related processes, and model very...

  13. Relationship between the erosion properties of soils and other parameters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil parameters are essential for erosion process prediction and ultimately improved model development, especially as they relate to dam and levee failure. Soil parameters including soil texture and structure, soil classification, soil compaction, moisture content, and degree of saturation can play...

  14. Soil erodibility for water erosion: A perspective and Chinese experiences

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Zheng, Fenli; Römkens, Mathias J. M.; Darboux, Frédéric

    2013-04-01

    Knowledge of soil erodibility is an essential requirement for erosion prediction, conservation planning, and the assessment of sediment related environmental effects of watershed agricultural practices. This paper reviews the status of soil erodibility evaluations and determinations based on 80 years of upland area erosion research mainly in China and the USA. The review synthesizes the general research progress made by discussing the basic concepts of erodibility and its evaluation, determination, and prediction as well as knowledge of its spatio-temporal variations. The authors found that soil erodibility is often inappropriately or inaccurately applied in describing soil loss caused by different soil erosion component processes and mechanisms. Soil erodibility indicators were related to intrinsic soil properties and exogenic erosional forces, measurements, and calculations. The present review describes major needs including: (1) improved definition of erodibility, (2) modified erodibility determinations in erosion models, especially for specific geographical locations and in the context of different erosion sub-processes, (3) advanced methodologies for quantifying erodibilities of different soil erosion sub-processes, and (4) a better understanding of the mechanism that causes temporal variations in soil erodibility. The review also provides a more rational basis for future research on soil erodibility and supports predictive modeling of soil erosion processes and the development of improved conservation practices.

  15. The role of soil surface water regimes and raindrop impact on hillslope soil erosion and nutrient losses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil surface water regimes on hill-slopes may appreciably affect soil erosion and nutrient losses. Different water regimes are often prevalent on different parts of the slope and therefore may affect these losses differently. A laboratory rainfall simulator study was conducted to determine the effec...

  16. Topographic variability and the influence of soil erosion on the carbon cycle

    NASA Astrophysics Data System (ADS)

    Dialynas, Yannis G.; Bastola, Satish; Bras, Rafael L.; Billings, Sharon A.; Markewitz, Daniel; Richter, Daniel deB.

    2016-05-01

    Soil erosion, particularly that caused by agriculture, is closely linked to the global carbon (C) cycle. There is a wide range of contrasting global estimates of how erosion alters soil-atmosphere C exchange. This can be partly attributed to limited understanding of how geomorphology, topography, and management practices affect erosion and oxidation of soil organic C (SOC). This work presents a physically based approach that stresses the heterogeneity at fine spatial scales of SOC erosion, SOC burial, and associated soil-atmosphere C fluxes. The Holcombe's Branch watershed, part of the Calhoun Critical Zone Observatory in South Carolina, USA, is the case study used. The site has experienced some of the most serious agricultural soil erosion in North America. We use SOC content measurements from contrasting soil profiles and estimates of SOC oxidation rates at multiple soil depths. The methodology was implemented in the tRIBS-ECO (Triangulated Irregular Network-based Real-time Integrated Basin Simulator-Erosion and Carbon Oxidation), a spatially and depth-explicit model of SOC dynamics built within an existing coupled physically based hydro-geomorphic model. According to observations from multiple soil profiles, about 32% of the original SOC content has been eroded in the study area. The results indicate that C erosion and its replacement exhibit significant topographic variation at relatively small scales (tens of meters). The episodic representation of SOC erosion reproduces the history of SOC erosion better than models that use an assumption of constant erosion in space and time. The net atmospheric C exchange at the study site is estimated to range from a maximum source of 14.5 g m-2 yr-1 to a maximum sink of -18.2 g m-2 yr-1. The small-scale complexity of C erosion and burial driven by topography exerts a strong control on the landscape's capacity to serve as a C source or a sink.

  17. Shrublands and Soil Erosion. An State-of-the-Art

    NASA Astrophysics Data System (ADS)

    García Estríngana, Pablo; Dunkerley, David; Cerdà, Artemi

    2014-05-01

    distribution controls the exposure of soils to rainfall drops affecting soil erosion (Cerdà, 1997a; Cammeraat et al., 2010; Kakembo et al., 2012). The lost of vegetation can trigger Desertification (Izzo et al., 2013) because soil erosion is highly dependent on the effective rainfall striking soil particles (Cerdà and Lasanta, 2005; Haile and Fetene; 2012; Miao et al., 2012, Prokop and Poręba, 2012). Shrubs are the most characteristic vegetation type in semiarid and arid ecosystems all over the world (Tomaselli, 1981; Kummerrow, 1989), typical of intermediate stages of most vegetation succession series, being the first in terms of dominant vegetation coverage, occupying 24% of drylands, followed by crop vegetation with 20% (Reynolds et al., 2007). Moreover, shrub vegetation covers the soil permanently, being able to adapt to very unfavourable conditions like droughts, frosts, non-fertile soils,… improving the soil quality due to their capacity to activate organic matter cycles supplying greater amounts of litter (Alegre et al., 2004). Shrubs have complex root systems, inducing changes in soil properties and increasing soil macroporosity (indirect effects) that increase infiltration reducing runoff and the soil loss (Garcia-Estringana et al., 2010). Shrubs improve the infiltration capacity of soils (Cerdà, 1997), even in the most difficult conditions (Marques et al., 2005), the water retention capacity (Ruiz Sinoga et al., 2010) and the runoff and sediment redistribution. Shrub vegetation has been seen as a key vegetation cover in semiarid lands to control the soil and water losses (Francis and Thornes, 1990; Barea et al., 1996; Romero Díaz, 2003; Cerdà and Doerr, 2007). But the majority of revegetation programmes in arid and semiarid regions still ignores the great potential of this type of vegetation. Romero Díaz et al. (2010) indicated that 99% of revegetation programmes carried out by public authorities in Spain used fast growing tree vegetation (Pinus sp. and

  18. Soil erosion increases soil microbial activity at the depositional position of eroding slopes

    NASA Astrophysics Data System (ADS)

    Meng, Xu; Cardenas, Laura M.; Donovan, Neil; Zhang, Junling; Murray, Phil; Zhang, Fusuo; Dungait, Jennifer A. J.

    2016-04-01

    Soil erosion is the most widespread form of soil degradation. Estimation of the impact of agricultural soil erosion on global carbon cycle is a topic of scientific debate, with opposing yet similar magnitude estimates of erosion as a net source or sink of atmospheric carbon. The transport and deposition of eroded agricultural soils affects not only the carbon cycle but other nutrient cycles as well. It has been estimated that erosion-induced lateral fluxes of nitrogen (N) and phosphorus (P) could be similar in magnitude to those from fertilizer application and crop removal (Quinton et al., 2010). In particular, the dynamics of soil N in eroding slopes need to be considered because the management of soil N has profound influences on the functioning of soil microorganisms, which are generally considered as the main biotic driver of soil C efflux. Carbon dioxide (CO2) emissions tend to increase in deposition positions of eroded slopes, diminishing the sink potential of eroded soils C (. As the global warming potential of nitrous oxide (N2O) is 310 times relative to that of CO2, the sink potential of agricultural erosion could easily be negated with a small increase in N2O emissions. Therefore, an investigation of the potential emissions of greenhouse gases, and especially N2O from soils affected by agricultural erosion, are required. In the present study, a field experiment was established with contrasting cultivation techniques of a C4 crop (Zea mays; δ13C = -12.2‰) to introduce 13C-enriched SOC to a soil previously cropped with C3 plants (δ13C = -29.3‰). Soils sampled from the top, middle, bottom and foot slope positions along a distinct erosion pathway were analyzed using 13C-phospholipid fatty acid (PLFA) analysis and incubated to investigate the responses of microorganisms and associated potential emissions of greenhouse gases (GHG). The total C and N contents were greatest in soils at the top slope position, whereas soil mineral N (NO3--N and NH4+-N

  19. Learning Style Responses to an Online Soil Erosion Lesson

    ERIC Educational Resources Information Center

    Mamo, Martha; Kettler, Timothy; Hussman, Dann

    2005-01-01

    Our objective was to evaluate responses from students with different learning styles to the use of computer technology as a supplemental tool in teaching soil erosion concepts. The online lesson utilized photographs, illustrations, animations, and an interactive model that allowed students to manipulate factors influencing soil erosion. Students…

  20. Simulation of unsteady flow and soil erosion in irrigation furrows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion in irrigation furrows significantly impacts the efficiency of irrigation,infiltration and fertilization. This study developed a one-dimensional numerical model to simulate unsteady flow and the resultant soil erosion and sediment transport in irrigation furrows. The model solves a revis...

  1. Simulation of unsteady flow and soil erosion in irrigation furrows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion in irrigation furrows significantly impacts the efficiency of irrigation, infiltration and fertilization. This study developed a numerical model to simulate unsteady flow and the resultant soil erosion and sediment transport in irrigation furrows. The model solves a revised version of t...

  2. Rates and spatial variations of soil erosion in Europe: A study based on erosion plot data

    NASA Astrophysics Data System (ADS)

    Cerdan, O.; Govers, G.; Le Bissonnais, Y.; Van Oost, K.; Poesen, J.; Saby, N.; Gobin, A.; Vacca, A.; Quinton, J.; Auerswald, K.; Klik, A.; Kwaad, F. J. P. M.; Raclot, D.; Ionita, I.; Rejman, J.; Rousseva, S.; Muxart, T.; Roxo, M. J.; Dostal, T.

    2010-10-01

    An extensive database of short to medium-term erosion rates as measured on erosion plots in Europe under natural rainfall was compiled from the literature. Statistical analysis confirmed the dominant influence of land use and cover on soil erosion rates. Sheet and rill erosion rates are highest on bare soil; vineyards show the second highest soil losses, followed by other arable lands (spring crops, orchards and winter crops). A land with a permanent vegetation cover (shrubs, grassland and forest) is characterised by soil losses which are generally more than an order of magnitude lower than those on arable land. Disturbance of permanent vegetation by fire leads to momentarily higher erosion rates but rates are still lower than those measured on arable land. We also noticed important regional differences in erosion rates. Erosion rates are generally much lower in the Mediterranean as compared to other areas in Europe; this is mainly attributed to the high soil stoniness in the Mediterranean. Measured erosion rates on arable and bare land were related to topography (slope steepness and length) and soil texture, while this was not the case for plots with a permanent land cover. We attribute this to a fundamental difference in runoff generation and sediment transfer according to land cover types. On the basis of these results we calculated mean sheet and rill erosion rates for the European area covered by the CORINE database: estimated rill and interrill erosion rates are ca. 1.2 t ha - 1 year - 1 for the whole CORINE area and ca. 3.6 t ha - 1 year - 1 for arable land. These estimates are much lower than some earlier estimates which were based on the erroneous extrapolation of small datasets. High erosion rates occur in areas dominated by vineyards, the hilly loess areas in West and Central Europe and the agricultural areas located in the piedmont areas of the major European mountain ranges.

  3. Ancient Agricultural Terraces and the Soil Erosion Paradox

    NASA Astrophysics Data System (ADS)

    Brown, Tony

    2015-04-01

    Geoarchaeology lies at the heart of debates about societal stability and change. Geomorphological research has been used as a foundation for simplistic models of resource depletion based almost entirely on the comparison of soil erosion rates with long-term so- called 'geological' rates. However, the neo-catastrophic collapse of complex agricultural societies is rare, and where it is convincing demonstrated it is even more rarely monocausal. Indeed many societies appear to have continued agricultural exploitation of climatically marginal lands for far longer than soil depletion estimates would forecast. One reason may be that this soil depletion approach has grossly simplified soil creation through weathering, and neglected how past agriculture also affected the soil creation rate (especially on some lithologies) and how soil was conserved (terraces) and utilised even after transport. However, we now have we know have some potentially valuable new tools, including mineral magnetics and cosmogenic nuclides, which can be used to estimate changing soil weathering rates. This approach will be discussed with examples from both the temperate and Mediterranean climatic zones and in relation to causative models of change in complex agricultural societies.

  4. Assessment of soil erosion susceptibility using empirical modeling

    NASA Astrophysics Data System (ADS)

    Guo, Jianping; Niu, Tao; Rahimy, Pooyan; Wang, Fu; Zhao, Haiying; Zhang, Jiahua

    2013-02-01

    Soil erosion is one of the most serious land degradation problems all over the world, causing irreversible land quality reduction. In this paper, we modify the Revised Universal Soil Loss Equation (RUSLE) model by replacing the factors of slope length and gradient with Sediment Transport Index (STI). The Digital Elevation Model, terrain parameters, Normalized Difference Vegetation Index (NDVI), and rainfall data are used as inputs to the model. Along with the application of remote sensing techniques and ground survey measurements, erosion susceptibility maps are produced. The revised models are then used to obtain the optimal estimate of soil erosion susceptibility at Alianello of southern Italy, which is prone to soil erosion. The soil loss estimated from the modified RUSLE model shows a large spatial variance, ranging from 10 to as much as 7000 ton ha-1 yr-1. The high erosion susceptible area constitutes about 46.8% of the total erosion area, and when classified by land cover type, 33% is "mixed bare with shrubs and grass", followed by 5.29% of "mixture of shrubs and trees", with "shrubs" having the lowest percentage of 0.06%. In terms of slope types, very steep slope accounts for a total of 40.90% and belongs to high susceptibility, whereas flat slope accounts for only 0.12%, indicating that flat topography has little effect on the erosion hazard. As far as the geomorphologic types are concerned, the type of "moderate steep-steep slopes with moderate to severe erosion" is most favorable to high soil erosion, which comprises about 9.34%. Finally, we validate the soil erosion map from the adapted RUSLE model against the visual interpretation map, and find a similarity degree of 71.9%, reflecting the efficiency of the adapted RUSLE model in mapping the soil erosion in this study area.

  5. Factors affecting the erosion resistance of weld overlays

    SciTech Connect

    Levin, B.F.; Dupont, J.N.; Marder, A.R.

    1996-12-31

    Research was conducted to study factors affecting the solid particle erosion resistance of weld overlay coatings. Eleven weld overlay alloys were deposited on 1018 steel substrates using the plasma arc welding process and erosion tested at 400 C. Erosion resistance was evaluated by determining the steady state erosion rate. Ultimet, Inconel-625, and 316L SS coatings showed the best erosion resistance at 30 and 90{degree} impact angles. Microhardness tests were performed on the eroded samples below the erosion surface to determine the size of the plastically deformed zone and it was found that one group of coatings deformed plastically as a result of the particle impact while the others did not. No correlations were found between average microhardness at 400 C and volumetric erosion rates for plastically deformed weld overlays. For this group of overlays erosion resistance was correlated to the area under the curve of microhardness versus distance from the eroded surface. The physical significance of this parameter is discussed. For coatings that did not deform plastically, an increase in average microhardness at 400 C led to an increase in their volumetric erosion rates. The possible erosion mechanisms for these coating groups are discussed.

  6. Tree species identity and functional traits but not species richness affect interrill erosion processes in young subtropical forests

    NASA Astrophysics Data System (ADS)

    Seitz, S.; Goebes, P.; Song, Z.; Bruelheide, H.; Härdtle, W.; Kühn, P.; Li, Y.; Scholten, T.

    2015-06-01

    Soil erosion is seriously threatening ecosystem functioning in many parts of the world. In this context, it is assumed that tree species richness and functional diversity of tree communities can play a critical role in improving ecosystem services such as erosion control. An experiment with 170 micro-scale runoff plots was conducted to investigate the influence of tree species richness and identity as well as tree functional traits on interrill erosion in a young forest ecosystem. An interrill erosion rate of 47.5 t ha-1 a-1 was calculated. This study provided evidence that different tree species affect interrill erosion, but higher tree species richness did not mitigate soil losses in young forest stands. Thus, different tree morphologies have to be considered, when assessing erosion under forest. High crown cover and leaf area index reduced soil losses in initial forest ecosystems, whereas rising tree height increased them. Even if a leaf litter cover was not present, remaining soil surface cover by stones and biological soil crusts was the most important driver for soil erosion control. Furthermore, soil organic matter had a decreasing influence on soil loss. Long-term monitoring of soil erosion under closing tree canopies is necessary and a wide range of functional tree traits should be taken into consideration in future research.

  7. From plot to regional scales: Effect of land use and soil type on soil erosion in the southern Amazon

    NASA Astrophysics Data System (ADS)

    Schindewolf, Marcus; Schultze, Nico; Amorim, Ricardo S. S.; Schmidt, Jürgen

    2015-04-01

    The corridor along the Brazilian Highway 163 in the Southern Amazon is affected by radical changes in land use patterns. In order to enable a model based assessment of erosion risks on different land use and soil types a transportable disc type rainfall simulator is applied to identify the most important infiltration and erosion parameters of the EROSION 3D model. Since particle detachment highly depends on experimental plot length, a combined runoff supply is used for the virtually extension of the plot length to more than 20 m. Simulations were conducted on the most common regional land use, soil management and soil types for dry and wet runs. The experiments are characterized by high final infiltration rates (0.3 - 2.5 mm*min^-1), low sediment concentrations (0.2-6.5 g*L^-1) and accordingly low soil loss rates (0.002-50 Kg*m^-2), strongly related to land use, applied management and soil type. Ploughed pastures and clear cuts reveal highest soil losses whereas croplands are less affected. Due to higher aggregate stabilities Ferrasols are less endangered than Acrisols. Derived model parameters are plausible, comparable to existing data bases and reproduce the effects of land use and soil management on soil loss. Thus it is possible to apply the EROSION 3D soil loss model in Southern Amazonia for erosion risk assessment and scenario simulation under changing climate and land use conditions.

  8. Erosivity, surface runoff, and soil erosion estimation using GIS-coupled runoff-erosion model in the Mamuaba catchment, Brazil.

    PubMed

    Marques da Silva, Richarde; Guimarães Santos, Celso Augusto; Carneiro de Lima Silva, Valeriano; Pereira e Silva, Leonardo

    2013-11-01

    This study evaluates erosivity, surface runoff generation, and soil erosion rates for Mamuaba catchment, sub-catchment of Gramame River basin (Brazil) by using the ArcView Soil and Water Assessment Tool (AvSWAT) model. Calibration and validation of the model was performed on monthly basis, and it could simulate surface runoff and soil erosion to a good level of accuracy. Daily rainfall data between 1969 and 1989 from six rain gauges were used, and the monthly rainfall erosivity of each station was computed for all the studied years. In order to evaluate the calibration and validation of the model, monthly runoff data between January 1978 and April 1982 from one runoff gauge were used as well. The estimated soil loss rates were also realistic when compared to what can be observed in the field and to results from previous studies around of catchment. The long-term average soil loss was estimated at 9.4 t ha(-1) year(-1); most of the area of the catchment (60%) was predicted to suffer from a low- to moderate-erosion risk (<6 t ha(-1) year(-1)) and, in 20% of the catchment, the soil erosion was estimated to exceed > 12 t ha(-1) year(-1). Expectedly, estimated soil loss was significantly correlated with measured rainfall and simulated surface runoff. Based on the estimated soil loss rates, the catchment was divided into four priority categories (low, moderate, high and very high) for conservation intervention. The study demonstrates that the AvSWAT model provides a useful tool for soil erosion assessment from catchments and facilitates the planning for a sustainable land management in northeastern Brazil. PMID:23652539

  9. Soil erosion, policy and management in China coastal zone

    NASA Astrophysics Data System (ADS)

    Lu, Qingshui; Gao, Zhiqiang; Chen, Qiao; Ning, Jicai; Shi, Runhe; Gao, Wei

    2013-09-01

    The coastal zone is very important in the world. China coastal zone was granted the first priority of developing economy in the late 1980s. Since then, high population density and rapid economic development hace caused intensive changes of LUCC in this zone. Those changes have lead to land degradation. Besides, China governments launched series of projects and policy to improve such problems. Those will inevitably cause to diverse spatial dynamics of land degradtion. However, the state of land degradation in certain time is still unknown. Soil erosion is an important indicator of land degradation.Therefore, we use RS images,RUSLE model to anlyze the spatial pattern of soil erosion for 2000. By spatial analysis, we found that soil erosion in China coastal zone is not serious. Widespread soil erosion is only occurred on coastal zones in Shandong, Hainan and werstern Guangdong Province. Although rainfall eosivity factor(R) is higher in southern coastal zone, erosion tends to occur on the slopes with lower LS values in northern coastal zone than southern coastal zone. Goevernments have enforced some policy to reduce the extent of soil erosion by conversion of farmland to woodland and barren mountains to woodland. But the difference between southern and northern coastal zone is still not realized. To improve soil eorosion in those areas, we should let governments put more funds to increase vegetation cover in north. Such study will provide helpful suggestions for governments to prevent soil erosion in coastal zone.

  10. Can we manipulate root system architecture to control soil erosion?

    NASA Astrophysics Data System (ADS)

    Ola, A.; Dodd, I. C.; Quinton, J. N.

    2015-09-01

    Soil erosion is a major threat to soil functioning. The use of vegetation to control erosion has long been a topic for research. Much of this research has focused on the above-ground properties of plants, demonstrating the important role that canopy structure and cover plays in the reduction of water erosion processes. Less attention has been paid to plant roots. Plant roots are a crucial yet under-researched factor for reducing water erosion through their ability to alter soil properties, such as aggregate stability, hydraulic function and shear strength. However, there have been few attempts to specifically manipulate plant root system properties to reduce soil erosion. Therefore, this review aims to explore the effects that plant roots have on soil erosion and hydrological processes, and how plant root architecture might be manipulated to enhance its erosion control properties. We demonstrate the importance of root system architecture for the control of soil erosion. We also show that some plant species respond to nutrient-enriched patches by increasing lateral root proliferation. The erosional response to root proliferation will depend upon its location: at the soil surface dense mats of roots may reduce soil erodibility but block soil pores thereby limiting infiltration, enhancing runoff. Additionally, in nutrient-deprived regions, root hair development may be stimulated and larger amounts of root exudates released, thereby improving aggregate stability and decreasing erodibility. Utilizing nutrient placement at specific depths may represent a potentially new, easily implemented, management strategy on nutrient-poor agricultural land or constructed slopes to control erosion, and further research in this area is needed.

  11. Effects of ephemeral gully erosion on soil degradation in a cultivated area in Sicily

    NASA Astrophysics Data System (ADS)

    La Spada, Carmelo; Capra, Antonina; Gelsomino, Antonio; Ollobarren del Barrio, Paul

    2015-04-01

    Water erosion is the main cause of soil degradation on cultivated lands under Mediterranean climate. In this conditions, gully erosion is a major contributor to loss of soil productivity due to the big amounts of soil removed from the most productive top-layer. However, only few studies on the effects of gully erosion and artificial controlling measures on soil degradation are available. The study analyzes the effects of the ephemeral gully erosion and infilling by tillage operations on several physical-chemical soil properties influencing the soil productivity. The study area is located in the center of Sicily, in an agricultural context characterized by ephemeral gully erosion. Five fields with different crops and soil characteristics affected by this type of erosion were selected. Currently, local farmers adopt the artificial measure to gully filling activities to control gully erosion and continue the same agricultural management practice. Therefore, the studied ephemeral gullies show a cyclic behavior. They appear during the rainy season, are erased from July to October by soil infill from areas adjacent to the channel using ordinary tillage equipment, and, in most years, they reappear in the same position during the following rainy season. For each situation, 20 samples were taken, located on 5 transects in the direction perpendicular to the ephemeral gully, in specific positions: 2 outside the erosive channel (one in the valley-deposit area and one upstream of the basin in the undisturbed area), and 3 along the same. For each transect, the samples were collected in 4 different positions: one inside the ephemeral gully, the other 3 in external points spaced to represent the areas affected by the annual process of erosion and infilling of the gully. For each sample, a set of the main chemical and physical soil characteristics which influence the soil fertility were determined: particle size, pH, electrical conductivity, total content of carbonates, nitrates

  12. Trees, more than shrubs, protect against soil erosion

    NASA Astrophysics Data System (ADS)

    Wendel, JoAnna

    2014-05-01

    Soil erosion and saltation—the transport of ground particles by wind—are significant producers of dust and can damage crops or lead to nutrient-poor soil in semiarid regions. These regions are particularly vulnerable to climate warming and increased human activity, which can exacerbate erosion and induce dust bowl-like conditions. Previous research and observations have shown that vegetation such as shrubs and trees can reduce soil erosion, but existing models do not account for variations in wind direction or strength.

  13. Modeling the reduction in soil loss due to soil armouring caused by rainfall erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface soil properties can change as a result of soil disturbances, erosion, or deposition. One process that can significantly change surface soil properties is soil armouring, which is the selective removal of finer particles by rill or interrill erosion, leaving an armoured layer of coarser parti...

  14. Identification of areas vulnerable to soil erosion risk in India using GIS methods

    NASA Astrophysics Data System (ADS)

    Biswas, H.; Raizada, A.; Mandal, D.; Kumar, S.; Srinivas, S.; Mishra, P. K.

    2015-11-01

    This paper attempts to provide information for policymakers and soil conservation planners in the form of district-wise soil erosion risk (SER) maps prepared for the state of Telangana, India. The SER values for each district were computed by extracting the information on grid-wise soil erosion and soil loss tolerance limit values existing on the country-scale in a GIS environment. The objectives of the study were to (i) identify the areas of the state with a high erosion risk, and (ii) identify areas with an urgent need of conservation measures. The results reveal that around 69 % of the state has a negligible risk of soil erosion above the tolerance limits, and does not call for immediate soil conservation measures. The remaining area (2.17 M ha) requires conservation planning. Four districts, viz. Adilabad, Warangal, Khammam, and Karimnagar are the most risk-prone with more than one-quarter of their total geographical areas showing net positive SER values. In order to obtain a clearer picture and categorize the districts based on their extent of vulnerability, weighted erosion risk values were computed. Adilabad, Warangal, and Khammam were identified as the worst-affected districts in terms of soil erosion, and therefore are in need of immediate attention of natural resource conservation.

  15. Identification of vulnerable areas to soil erosion risk in India using GIS methods

    NASA Astrophysics Data System (ADS)

    Biswas, H.; Raizada, A.; Mandal, D.; Kumar, S.; Srinivas, S.; Mishra, P. K.

    2015-06-01

    This paper attempts to provide information for policy makers and soil conservation planners in the form of district-wise soil erosion risk (SER) maps prepared for the state of Telengana, India. The SER values for each district were computed by extracting the information on grid-wise soil erosion and soil loss tolerance limit values existing on the country-scale in a GIS environment. The objectives of the study were to (i) identify the areas of the state with high erosion risk, and (ii) identify areas with urgent needs of conservation measures. The results reveal that around 69% of the state has negligible risk of soil erosion above the tolerance limits, and does not call for immediate soil conservation measures. The remaining area (2.17M ha) requires conservation planning. Four districts, viz. Adilabad, Warangal, Khammam and Karimnagar are the most risk prone with more than one-fourth of their total geographical areas showing net positive SER values. In order to obtain a clearer picture and categorize the districts based on their extent of vulnerability, the Weighted Erosion Risk values were computed. Adilabad, Warangal and Khammam were identified as the worst-affected districts in terms of soil erosion and therefore need immediate attention for natural resource conservation.

  16. Climate change impact on soil erosion in the Mandakini River Basin, North India

    NASA Astrophysics Data System (ADS)

    Khare, Deepak; Mondal, Arun; Kundu, Sananda; Mishra, Prabhash Kumar

    2016-05-01

    Correct estimation of soil loss at catchment level helps the land and water resources planners to identify priority areas for soil conservation measures. Soil erosion is one of the major hazards affected by the climate change, particularly the increasing intensity of rainfall resulted in increasing erosion, apart from other factors like landuse change. Changes in climate have an adverse effect with increasing rainfall. It has caused increasing concern for modeling the future rainfall and projecting future soil erosion. In the present study, future rainfall has been generated with the downscaling of GCM (Global Circulation Model) data of Mandakini river basin, a hilly catchment in the state of Uttarakhand, India, to obtain future impact on soil erosion within the basin. The USLE is an erosion prediction model designed to predict the long-term average annual soil loss from specific field slopes in specified landuse and management systems (i.e., crops, rangeland, and recreational areas) using remote sensing and GIS technologies. Future soil erosion has shown increasing trend due to increasing rainfall which has been generated from the statistical-based downscaling method.

  17. Modelling the historical changes in physical soil properties caused by wind erosion process

    NASA Astrophysics Data System (ADS)

    Lackóová, Lenka

    2016-04-01

    Soil physical properties could be significantly affected by land degradation processes. Spatial variation modelling of physical soil properties in time is important in areas where wind erosion occurs regularly. The objectives of this study were to determine the changes of spatial variability of sand, silt and clay % contents in selected area in Slovakia over 45 years using topsoil physical properties at European scale (using LUCAS topsoil) and historical Complex Soil Survey Data. The Complex Soil Survey was made in the period 1960-1970 for the whole of the Slovak Republic, using a unified methodology to build an important soil properties database including physical topsoil properties. Spatial model distribution using regression kriging algorithm created by Soil Science and Conservation Research Institute was used for comparison with LUCAS topsoil particle size distribution datasets and their derived products of clay, sand and silt % content. The results of this study will show the effects of wind erosion in long time scale. Continual total mass removal during wind erosion can produce dramatic changes in the texture of the soil surface. Fine particles are removed, which tend to concentrate sand as erosion continues. Wind erosion physically removes the most fertile portion of the soil which may lead to lower productivity or destroying the characteristics of topsoil beneficial to plant growth. Historical changes of physical soil properties are discussed in this study.

  18. Modelling soil erosion at European scale: towards harmonization and reproducibility

    NASA Astrophysics Data System (ADS)

    Bosco, C.; de Rigo, D.; Dewitte, O.; Poesen, J.; Panagos, P.

    2015-02-01

    Soil erosion by water is one of the most widespread forms of soil degradation. The loss of soil as a result of erosion can lead to decline in organic matter and nutrient contents, breakdown of soil structure and reduction of the water-holding capacity. Measuring soil loss across the whole landscape is impractical and thus research is needed to improve methods of estimating soil erosion with computational modelling, upon which integrated assessment and mitigation strategies may be based. Despite the efforts, the prediction value of existing models is still limited, especially at regional and continental scale, because a systematic knowledge of local climatological and soil parameters is often unavailable. A new approach for modelling soil erosion at regional scale is here proposed. It is based on the joint use of low-data-demanding models and innovative techniques for better estimating model inputs. The proposed modelling architecture has at its basis the semantic array programming paradigm and a strong effort towards computational reproducibility. An extended version of the Revised Universal Soil Loss Equation (RUSLE) has been implemented merging different empirical rainfall-erosivity equations within a climatic ensemble model and adding a new factor for a better consideration of soil stoniness within the model. Pan-European soil erosion rates by water have been estimated through the use of publicly available data sets and locally reliable empirical relationships. The accuracy of the results is corroborated by a visual plausibility check (63% of a random sample of grid cells are accurate, 83% at least moderately accurate, bootstrap p ≤ 0.05). A comparison with country-level statistics of pre-existing European soil erosion maps is also provided.

  19. Soil erosion assessment and control in Northeast Wollega, Ethiopia

    NASA Astrophysics Data System (ADS)

    Adugna, A.; Abegaz, A.; Cerdà, A.

    2015-12-01

    Soil erosion is the main driver of land degradation in Ethiopia, and in the whole region of East Africa. This study was conducted at the Northeast Wollega in West Ethiopia to estimate the soil losses by means of the Revised Universal Soil Loss Equation (RUSLE). The purpose of this paper is to identify erosion spot areas and target locations for appropriate development of soil and water conservation measures. Fieldwork and household survey were conducted to identify major determinants of soil erosion control. Six principal factors were used to calculate soil loss per year, such as rainfallerosivity, soil erodiblity, slope length, slope steepness, crop management and erosion-control practices. The soil losses have shown spatio-temporal variations that range from 4.5 Mg ha-1 yr-1 in forest to 65.9 Mg ha-1 yr-1 in cropland. Results from the analysis of stepwise multiple linear regression show that sustainable soil erosion control are determined byknowledge of farmers about soil conservation, land tenure security and off-farm income at community level. Thus, policy aim at keeping land productivity will need to focus on terracing, inter-cropping and improved agro-forestry practices.

  20. Soil Erosion: Advanced Crop and Soil Science. A Course of Study.

    ERIC Educational Resources Information Center

    Miller, Larry E.

    The course of study represents the last of six modules in advanced crop and soil science and introduces the agriculture student to the topic of soil erosion. Upon completion of the two day lesson, the student will be able to: (1) define conservation, (2) understand how erosion takes place, and (3) list ways of controlling wind and water erosion.…

  1. Soil erosion by snow gliding - a first quantification attempt in a subalpine area in Switzerland

    NASA Astrophysics Data System (ADS)

    Meusburger, K.; Leitinger, G.; Mabit, L.; Mueller, M. H.; Walter, A.; Alewell, C.

    2014-09-01

    Snow processes might be one important driver of soil erosion in Alpine grasslands and thus the unknown variable when erosion modelling is attempted. The aim of this study is to assess the importance of snow gliding as a soil erosion agent for four different land use/land cover types in a subalpine area in Switzerland. We used three different approaches to estimate soil erosion rates: sediment yield measurements in snow glide depositions, the fallout radionuclide 137Cs and modelling with the Revised Universal Soil Loss Equation (RUSLE). RUSLE permits the evaluation of soil loss by water erosion, the 137Cs method integrates soil loss due to all erosion agents involved, and the measurement of snow glide deposition sediment yield can be directly related to snow-glide-induced erosion. Further, cumulative snow glide distance was measured for the sites in the winter of 2009/2010 and modelled for the surrounding area and long-term average winter precipitation (1959-2010) with the spatial snow glide model (SSGM). Measured snow glide distance confirmed the presence of snow gliding and ranged from 2 to 189 cm, with lower values on the north-facing slopes. We observed a reduction of snow glide distance with increasing surface roughness of the vegetation, which is an important information with respect to conservation planning and expected and ongoing land use changes in the Alps. Snow glide erosion estimated from the snow glide depositions was highly variable with values ranging from 0.03 to 22.9 t ha-1 yr-1 in the winter of 2012/2013. For sites affected by snow glide deposition, a mean erosion rate of 8.4 t ha-1 yr-1 was found. The difference in long-term erosion rates determined with RUSLE and 137Cs confirms the constant influence of snow-glide-induced erosion, since a large difference (lower proportion of water erosion compared to total net erosion) was observed for sites with high snow glide rates and vice versa. Moreover, the difference between RUSLE and 137Cs erosion

  2. Can control of soil erosion mitigate water pollution by sediments?

    PubMed

    Rickson, R J

    2014-01-15

    The detrimental impact of sediment and associated pollutants on water quality is widely acknowledged, with many watercourses in the UK failing to meet the standard of 'good ecological status'. Catchment sediment budgets show that hill slope erosion processes can be significant sources of waterborne sediment, with rates of erosion likely to increase given predicted future weather patterns. However, linking on-site erosion rates with off-site impacts is complicated because of the limited data on soil erosion rates in the UK and the dynamic nature of the source-pathway-receptor continuum over space and time. Even so, soil erosion control measures are designed to reduce sediment production (source) and mobilisation/transport (pathway) on hill slopes, with consequent mitigation of pollution incidents in watercourses (receptors). The purpose of this paper is to review the scientific evidence of the effectiveness of erosion control measures used in the UK to reduce sediment loads of hill slope origin in watercourses. Although over 73 soil erosion mitigation measures have been identified from the literature, empirical data on erosion control effectiveness are limited. Baseline comparisons for the 18 measures where data do exist reveal erosion control effectiveness is highly variable over time and between study locations. Given the limitations of the evidence base in terms of geographical coverage and duration of monitoring, performance of the different measures cannot be extrapolated to other areas. This uncertainty in effectiveness has implications for implementing erosion/sediment risk reduction policies, where quantified targets are stipulated, as is the case in the EU Freshwater Fish and draft Soil Framework Directives. Also, demonstrating technical effectiveness of erosion control measures alone will not encourage uptake by land managers: quantifying the costs and benefits of adopting erosion mitigation is equally important, but these are uncertain and difficult to

  3. Assessing soil quality indicator under different land use and soil erosion using multivariate statistical techniques.

    PubMed

    Nosrati, Kazem

    2013-04-01

    Soil degradation associated with soil erosion and land use is a critical problem in Iran and there is little or insufficient scientific information in assessing soil quality indicator. In this study, factor analysis (FA) and discriminant analysis (DA) were used to identify the most sensitive indicators of soil quality for evaluating land use and soil erosion within the Hiv catchment in Iran and subsequently compare soil quality assessment using expert opinion based on soil surface factors (SSF) form of Bureau of Land Management (BLM) method. Therefore, 19 soil physical, chemical, and biochemical properties were measured from 56 different sampling sites covering three land use/soil erosion categories (rangeland/surface erosion, orchard/surface erosion, and rangeland/stream bank erosion). FA identified four factors that explained for 82 % of the variation in soil properties. Three factors showed significant differences among the three land use/soil erosion categories. The results indicated that based upon backward-mode DA, dehydrogenase, silt, and manganese allowed more than 80 % of the samples to be correctly assigned to their land use and erosional status. Canonical scores of discriminant functions were significantly correlated to the six soil surface indices derived of BLM method. Stepwise linear regression revealed that soil surface indices: soil movement, surface litter, pedestalling, and sum of SSF were also positively related to the dehydrogenase and silt. This suggests that dehydrogenase and silt are most sensitive to land use and soil erosion. PMID:22791019

  4. Wildfires effect on water erosion response of different mediterranean forest soils

    NASA Astrophysics Data System (ADS)

    Andreu, V.; Forteza, J.; Rubio, J. L.

    2009-04-01

    Some of the morphological characteristics of the Mediterranean landscapes are partly due to the incidence of forest fires. Different intensities and different environmental conditions give place to different forms of water erosion responses and ways of ecosystems recovery. In this work, the effect of fire on the response to erosion processes of different type of soils under different environmental conditions has been studied. Immediately after a wildfire that affected 9478 ha of the Sierra Calderona (Valencia, SPAIN), six monitoring stations to study the evolution of water erosion processes were placed. The stations cover different fire intensities and environmental situations. Topographical, pedological and vegetation characteristics of each station were studied. The effect of erosive rain events on runoff and sediment production, during a five years period was evaluated. Erosive patterns in the studied zones were similar, but with slight variations depending on the rainfall distribution on the whole area and the different topographical conditions. The data show that, in general, for all the stations the most important soil losses were produced in the first four months after the fire, and then these losses decrease progressively with time. Although the data show high heterogeneity, it has been observed that together with the intrinsic characteristics of fire and rain events, soil profile properties can also be determinant factors in the incidence of water erosion and in the recovery of the vegetation cover under similar environmental conditions. Keywords: Wildfires, Mediterranean soils, water erosion, soil loss, runoff generation, rain aggressiveness.

  5. Soil carbon and nitrogen erosion in forested catchments: implications for erosion-induced terrestrial carbon sequestration

    NASA Astrophysics Data System (ADS)

    Stacy, E.; Hart, S. C.; Hunsaker, C. T.; Johnson, D. W.; Berhe, A. A.

    2015-02-01

    Soil erosion plays important roles in organic matter (OM) storage and persistence in dynamic landscapes. The biogeochemical implication of soil erosion has been a focus of a growing number of studies over the last two decades. However, most of the available studies are conducted in agricultural systems or grasslands, and hence very little information is available on rate and nature of soil organic matter (SOM) eroded from forested upland ecosystems. In the southern parts of the Sierra Nevada Mountains in California, we determined the rate of carbon (C) and nitrogen (N) eroded from two sets of catchments under different climatic conditions to determine how the amount and distribution of precipitation affects lateral distribution of topsoil and associated SOM. We quantified sediment and SOM exported annually (for water years 2005-2011) from four low-order, snow-dominated catchments, and four low-order catchments that receive a mix of rain, and snow and compared it to soil at three different landform positions from the source slopes to determine if there is selective transport of some soil OM components. We found that the amount of sediment exported varied from 0.4 to 177 kg N ha-1, while export of particulate C was between 0.025 and 4.2 kg C ha-1, compared to export of particulate N that was between 0.001 and 0.04 kg ha-1. Sediment yield and composition showed high interannual variation, with higher C and N concentrations in sediment collected in drier years. In our study catchments, erosion laterally mobilized OM-rich topsoil and litter material, some of which readily enters streams owing to the topography in these catchments that includes steep slopes adjacent to stream channels. Annual lateral sediment mass, C, and N fluxes were positively and strongly correlated with stream flows. Our results suggest that variability in climate, represented by stream discharge, is a primary factor controlling the magnitude of C and N eroded from upland temperature forest

  6. Polyacrylamide molecular weight effects on soil infiltration and erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seal formation at the surface of smectitic soils during rainstorms reduces soil infiltration rate (IR) and causes runoff and erosion. Surface application of dry anionic polyacrylamide (PAM) with high molecular weight (MW) has been found to be effective in stabilizing soil aggregates, and decreasing ...

  7. Shrublands and Soil Erosion. An State-of-the-Art

    NASA Astrophysics Data System (ADS)

    García Estríngana, Pablo; Dunkerley, David; Cerdà, Artemi

    2014-05-01

    distribution controls the exposure of soils to rainfall drops affecting soil erosion (Cerdà, 1997a; Cammeraat et al., 2010; Kakembo et al., 2012). The lost of vegetation can trigger Desertification (Izzo et al., 2013) because soil erosion is highly dependent on the effective rainfall striking soil particles (Cerdà and Lasanta, 2005; Haile and Fetene; 2012; Miao et al., 2012, Prokop and Poręba, 2012). Shrubs are the most characteristic vegetation type in semiarid and arid ecosystems all over the world (Tomaselli, 1981; Kummerrow, 1989), typical of intermediate stages of most vegetation succession series, being the first in terms of dominant vegetation coverage, occupying 24% of drylands, followed by crop vegetation with 20% (Reynolds et al., 2007). Moreover, shrub vegetation covers the soil permanently, being able to adapt to very unfavourable conditions like droughts, frosts, non-fertile soils,… improving the soil quality due to their capacity to activate organic matter cycles supplying greater amounts of litter (Alegre et al., 2004). Shrubs have complex root systems, inducing changes in soil properties and increasing soil macroporosity (indirect effects) that increase infiltration reducing runoff and the soil loss (Garcia-Estringana et al., 2010). Shrubs improve the infiltration capacity of soils (Cerdà, 1997), even in the most difficult conditions (Marques et al., 2005), the water retention capacity (Ruiz Sinoga et al., 2010) and the runoff and sediment redistribution. Shrub vegetation has been seen as a key vegetation cover in semiarid lands to control the soil and water losses (Francis and Thornes, 1990; Barea et al., 1996; Romero Díaz, 2003; Cerdà and Doerr, 2007). But the majority of revegetation programmes in arid and semiarid regions still ignores the great potential of this type of vegetation. Romero Díaz et al. (2010) indicated that 99% of revegetation programmes carried out by public authorities in Spain used fast growing tree vegetation (Pinus sp. and

  8. Modelling soil erosion at European scale: towards harmonization and reproducibility

    NASA Astrophysics Data System (ADS)

    Bosco, C.; de Rigo, D.; Dewitte, O.; Poesen, J.; Panagos, P.

    2014-04-01

    Soil erosion by water is one of the most widespread forms of soil degradation. The loss of soil as a result of erosion can lead to decline in organic matter and nutrient contents, breakdown of soil structure and reduction of the water holding capacity. Measuring soil loss across the whole landscape is impractical and thus research is needed to improve methods of estimating soil erosion with computational modelling, upon which integrated assessment and mitigation strategies may be based. Despite the efforts, the prediction value of existing models is still limited, especially at regional and continental scale. A new approach for modelling soil erosion at large spatial scale is here proposed. It is based on the joint use of low data demanding models and innovative techniques for better estimating model inputs. The proposed modelling architecture has at its basis the semantic array programming paradigm and a strong effort towards computational reproducibility. An extended version of the Revised Universal Soil Loss Equation (RUSLE) has been implemented merging different empirical rainfall-erosivity equations within a climatic ensemble model and adding a new factor for a better consideration of soil stoniness within the model. Pan-European soil erosion rates by water have been estimated through the use of publicly available datasets and locally reliable empirical relationships. The accuracy of the results is corroborated by a visual plausibility check (63% of a random sample of grid cells are accurate, 83% at least moderately accurate, bootstrap p ≤ 0.05). A comparison with country level statistics of pre-existing European maps of soil erosion by water is also provided.

  9. Soil erosion in the Alps (spatial analysis of causes and risk assessment)

    NASA Astrophysics Data System (ADS)

    Meusburger, Katrin; Alewell, Christine

    2010-05-01

    Increasing numbers of tourists, changes in farming/cultivation techniques and global warming are expected to intensity soil erosion in the Alps. Therefore, the knowledge of the relations between triggering factors (e.g. hydrology and snow cover, stability of vegetation cover, landuse intensity etc.) and soil erosion in mountain regions will be of crucial importance in the near future. The aim of this project is the identification of causes of soil erosion in alpine environments as well as the mapping of risk areas rather than an exact quantification of sediment rates. The methods to determine erosion risk are developed within a subcatchment (30 km2) of the Furkareuss (Urseren valley, 1400-2500 m a.s.l.) in the Swiss Alps and are to be validated by upscaling to the whole catchment (80 km2). Soil erosion is linked to runoff processes. In contrast to flat regions,subsurface flow has to be considered in addition to overland flow. The latter may initiate soil slips. The valley slopes of the investigated area are affected by both water surface erosion and soil slips. Preliminary soil surveys and erosion mapping were conducted. To delineate risk zones, the various soil types found were grouped into soilscapes according to parameters with relevance for soil stability. It could be shown that soil slips occurred predominantly in the zone of hydromorphic soils, which also verified the linkage between subsurface flow and soil slips. However, a comparison between hillslopes most affected by erosion and undisturbed slopesindicated that they also differed in geology, vegetation and landuse. The weight of these triggering factors will be evaluated by spatial statistical analysis. To assess whether erosion actually increased during the last decades or whether we observe a natural equilibrium-process of degradation and regeneration, sequences of aerial photographs for seven different years starting in 1959 and recent field mapping were analysed and compared. Special attention is

  10. Effect of soil properties on the determination of riverbank erosion probability

    NASA Astrophysics Data System (ADS)

    Karatzas, George; Varouchakis, Emmanouil

    2016-04-01

    Riverbank erosion is a natural geomorphological process that affects the fluvial environment. The most important issue concerning riverbank erosion is the identification of the vulnerable locations. An alternative to the common hydrodynamic models to predict vulnerable locations is to quantify the probability of erosion occurrence. This can be achieved by identifying the underlying relations between riverbank erosion and the riverbank soil properties. Thus, riverbank erosion can be determined by a statistical methodology using independent variables that are considered to affect the erosion process. The impact of such variables may vary spatially, therefore, a non-stationary regression model is preferred instead of a stationary equivalent. Locally Weighted Logistic Regression (LWLR) is applied to predict the probability of presence or absence of erosion at the riverbanks of a river section. The erosion occurrence probability can be calculated in conjunction with the model deviance regarding the independent variables tested. The developed statistical model is applied to the Koiliaris River Basin on the island of Crete, Greece. The proposed statistical model is a useful tool that quantifies the erosion probability along the riverbanks and can be used to assist managing erosion and flooding events.

  11. Soil erosion-vegetation interactions in Mediterranean-dry reclaimed mining slopes

    NASA Astrophysics Data System (ADS)

    Moreno de las Heras, Mariano; Merino-Martín, Luis; Espigares, Tíscar; Nicolau, José M.

    2014-05-01

    Mining reclamation in Mediterranean-dry environments represents a complex task. Reclaimed mining slopes are particularly vulnerable to the effects of accelerated soil erosion processes, especially when these processes lead to the formation of rill networks. On the other hand, encouraging early vegetation establishment is perceived as indispensable to reduce the risk of degradation in these man-made ecosystems. This study shows a synthesis of soil erosion-vegetation research conducted in reclaimed mining slopes at El Moral field site (Teruel coalfield, central-east Spain). Our results highlight the role of rill erosion processes in the development of reclaimed ecosystems. Runoff routing is conditioned by the development of rill networks, maximizing the loss of water resources at the slope scale by surface runoff and altering the spatial distribution of soil moisture. As a result, the availability of water resources for plant growth is drastically reduced, affecting vegetation development. Conversely, vegetation exerts a strong effect on soil erosion: erosion rates rapidly decrease with vegetation cover and no significant rill erosion is usually observed after a particular cover threshold is reached. These interactive two-way vegetation-soil erosion relationships are further studied using a novel modeling approach that focuses on stability analysis of water-limited reclaimed slopes. Our framework reproduces two main groups of trends along the temporal evolution of reclaimed slopes: successful trends, characterized by widespread vegetation development and the effective control of rill erosion processes; and gullying trends, characterized by the progressive loss of vegetation and a sharp logistic increase in erosion rates. This stability-analysis also facilitates the determination of threshold values for both vegetation cover and rill erosion that drive the long-term reclamation results, assisting the identification of critical situations that require specific human

  12. 7 CFR 610.12 - Equations for predicting soil loss due to water erosion.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ASSISTANCE Soil Erosion Prediction Equations § 610.12 Equations for predicting soil loss due to water erosion. (a) The equation for predicting soil loss due to erosion for both the USLE and the RUSLE is A = R × K... information about RUSLE see the U.S. Department of Agriculture Handbook 703, “Predicting Soil Erosion by...

  13. 7 CFR 610.12 - Equations for predicting soil loss due to water erosion.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ASSISTANCE Soil Erosion Prediction Equations § 610.12 Equations for predicting soil loss due to water erosion. (a) The equation for predicting soil loss due to erosion for both the USLE and the RUSLE is A = R × K... information about RUSLE see the U.S. Department of Agriculture Handbook 703, “Predicting Soil Erosion by...

  14. Soil erosion in a man-made landscape: the Mediterranean

    NASA Astrophysics Data System (ADS)

    Cerdà, A.; Ruiz Sinoga, J. D.; Cammeraat, L. H.

    2012-04-01

    Mediterranean-type ecosystems are characterised by a seasonally contrasted distribution of precipitation, by the coincidence of the driest and hottest season in summer, by an often-mountainous terrain, and by a long history of intense human occupation, especially around the Mediterranean Sea. The history of the Mediterranean lands is the history of human impacts on the soil system, and soil erosion is the most intense and widespread impact on this land where high intensity and uneven rainfall is found. A review of the soil erosion rates measured in the Mediterranean basin will be shown. The measurements done by means of erosion pins, topographical measurements, rainfall simulators, Gerlach collectors in open or close plots, watershed/basin measurements, reservoirs siltation and historical data will be shown. A review of the soil erosion models applied in the Mediterranean will be shown. The tentative approach done until October 2011 show that the soil erosion rates on Mediterranean type ecosystems are not as high as was supposed by the pioneers in the 70's. And this is probably due to the fact that the soils are very shallow and sediments are not available after millennia of high erosion rates. This is related to the large amount of rock fragments are covering the soil, and the rock outcrops that are found in the upper slope trams and the summits. Soil erosion in the Mediterranean is seasonal due to the rainfall concentration in winter, and highly variable within years as the high intensity rainfall events control the sediment production. Natural vegetation is adapted to the Mediterranean environmental conditions, and they are efficient to control the soil losses. An example are the forest fire that increase the soil losses but this is a temporal change as after 2-4 years the soil erosion rates are similar to the pre-fire period. Agriculture lands are the source of sediments although the highest erosion rates are found in badland areas that cover a small part of

  15. Monitoring soil erosion processes: The erosion plots at the Geocampus, University of Trier

    NASA Astrophysics Data System (ADS)

    Lassu, Tamas; Rodrigo Comino, Jesús; Seeger, Manuel; Ries, Johannes B.

    2015-04-01

    Long term monitoring on erosion plots is one of the most reliable methods to quantify the actual soil erosion rates. Although the direct extrapolation of the measured data to regional scale is problematic, due to the high spatial and temporal variability of the soil erosion processes, they provide indispensable experimental data for soil erosion model conception, calibration and validation. At the University Trier in 2013 four test plots were put into practice on colluvial loess loam soil with dimension 3 x 10 m and similar properties. They are representative for the regional conditions. The plots are located 265 m above sea level and they have a general inclination of 12-13°. In 2012 on two plots subsoiling was applied in order to reduce the compaction caused by the heavy machinery used during the construction of the plots. The two other plots were not disturbed and no melioration measures were applied. In the first year of the experiment after the preparation of the parcels, they were left for a spontaneous revegetation. Total runoff and sediment removal data was collected weekly, additionally a meteorological station provides continuously data about climate conditions. The data evaluation of the first year 2013/14 revealed big difference between the single plots. Total runoff was measured between 0 and 4.76 l m-2 (m=0.8 l m-2), total eroded sediment between 0 and 3.86 g m-2 (m=0.21 g m-2) weekly. The higher rates were recorded on the plots without subsoiling. After the first year, total eroded soil was calculated. The results were between 0.03 and 0.17 t ha-1a-1. With the help of the erosion plots at the University of Trier, the impact of the different soil use management concepts and cultivation techniques on runoff and erosion dynamics can be evaluated, additionally reliable data for modeling soil erosion can be generated as well.

  16. Mechanics of aeolian processes: Soil erosion and dust production

    NASA Technical Reports Server (NTRS)

    Mehrabadi, M. M.

    1989-01-01

    Aeolian (wind) processes occur as a result of atmosphere/land-surface system interactions. A thorough understanding of these processes and their physical/mechanical characterization on a global scale is essential to monitoring global change and, hence, is imperative to the fundamental goal of the Earth observing system (Eos) program. Soil erosion and dust production by wind are of consequence mainly in arid and semi arid regions which cover 36 percent of the Earth's land surface. Some recent models of dust production due to wind erosion of agricultural soils and the mechanics of wind erosion in deserts are reviewed and the difficulties of modeling the aeolian transport are discussed.

  17. Soil Erosion Protection Potential of Young Paulownia Plantation

    NASA Astrophysics Data System (ADS)

    Stepchich, Avgusta; Djodjov, Christo

    2014-05-01

    Soil erosion is removal of soil and rock particles by water, wind, ice and gravity. It is widely recognized as a global soil threat. Soils impacted by different forms of erosion cover large areas around the world. While landscape, soil and climate conditions trigger soil erosion processes, the vegetation cover reduces the soil erosion risk. About 60 % of the area of agricultural land in Bulgaria is under erosion risk, which necessitates implementation of series of measures for soil erosion control. The aim of this study is to determine the erosion protection potential and the loss of soil nutrients of young Paulownia plantation. Field experiments have been set up under unirrigated conditions at the experimental field for soil erosion studies of the N. Poushkarov Institute of Soil Science, Agrotechnology and Plant Protection near Suhodol. The local soils are Chromic Luvisols, moderately eroded. The altitude is 750 m and the slope gradient is 80. The experiment consists of four field plots for soil erosion studies, three of which planted with Paulownia Bellissima and a reference one with bare soil. The plants have been planted at a distance of 2 m between adjacent rows and 1 m between each two plants within the row. The size of each field plot is 32 m2 (4 m width and 8 m length). The plots are equipped with containers for collecting the surface runoff caused by erosive rainfall events. Biometrics, including the root-striking of the plants, their growth in height, foliage cover (projection) and stem diameter, was studied from May 13th to October 21st. The data reported cover the results from the studies during the first vegetation period after planting in the Spring of 2013. During the year four erosive rainfalls were observed with a total amount of 79.2 mm, resulting to a total amount of soil loss of 772 kg/ha from a planted plot and 551 kg/ha from bear soil. The total surface runoff is 156.7 m3/ha from planted plot and 153.1 m3/ha from bare soil. The total losses of

  18. Reduction of livelihood risk for river bank erosion affected villagers

    NASA Astrophysics Data System (ADS)

    Majumder, S. Sen; Fox, D. M.; Chakrabari, S.; Bhandari, G.

    2014-12-01

    Bank erosion process of the Ganga River created a serious livelihood risk for the villagers situated on left bank of the river in Malda district of the State of West Bengal, India since last four decades. Due to the erosion of agriculture land by the river, most of the villagers having agriculture as their only means of livelihood became jobless suddenly. Presently they are living in a miserable condition. One of the main objectives of this paper is to find out an alternative means of livelihood for the victims to improve their miserable socio-economic condition. It has been found from field survey that some erosion affected villagers have started to live and practice agriculture temporarily on the riverine islands (large and stable since thirteen years) as these islands have very fertile soil. If the re-emerged land plots can again be demarcated on the newly formed islands and distributed among the landless people to practice agriculture over there, then it will be a useful alternative livelihood strategy for the victims. The demarcation of re-emerged plots can be achieved by georeferencing the cadastral maps and then overlaying the plots on the present river course. In the present study area geo-referencing process of the cadastral maps became a serious issue as the study area has been very dynamic in terms of land cover and land use. Most of the villages were lost into the river course. Thus the common permanent features, required for geo-referencing, shown in the cadastral maps (surveyed during 1954-1962) were not found in the present satellite images. The second important objective of the present study is to develop a proper methodology for geo-referencing the cadastral maps of this area. The Spatial Adjustment Transformation and Automatic Digitization tools of Arc GIS were used to prepare geo-referenced plot maps. In Projective Transformation method the geometrically corrected block maps having village boundaries were used as source file. Then the

  19. Atrazine incorporation and soil erosion: balancing competing water quality concerns for claypan soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the U.S. Corn Belt, claypan soils are vulnerable to both erosion and transport of unincorporated herbicides. Thus, there is a need to identify tillage practices that can achieve a balance between herbicide transport and soil erosion for these soils. The objectives of this research were to compare...

  20. Characterisation of soil microtopography effects on runoff and soil erosion rates under simulated rainfall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil surface roughness is commonly identified as one of the dominant factors governing runoff and interrill erosion. Yet, because of difficulties in acquiring the data, most studies pay little attention to soil surface roughness. This is particularly true for soil erosion models which commonly don't...

  1. Ecological site-based assessments of wind and water erosion: Informing accelerated soil erosion management in rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper explores how soil erosion assessments structured across ecological sites can inform systems for managing accelerated soil erosion in rangelands. We evaluated wind and water erosion rates for five ecological sites in southern New Mexico, USA, using monitoring data and rangeland-specific wi...

  2. Effects of stubble and mulching on soil erosion by wind in semi-arid China.

    PubMed

    Cong, Peifei; Yin, Guanghua; Gu, Jian

    2016-01-01

    Soil erosion is a growing challenge for agricultural production in Northern China. To explore the effect of variation in stubble height and mulching biomass on soil erosion caused by wind, we conducted a field experiment using a quadratic rotation combination design. Results showed that the quantity of straw mulch was the dominant factor affecting soil erosion, and stubble height was of secondary importance. The soil water content in stubble and straw mulching treatments was higher than in a control treatment at 0-20 cm soil, and the tendency in the amount of soil water content was opposite to the amount of wind erosion (r = -0.882, n = 10, p < 0.01). The change in soil water content observed in the stubble and mulch treatments at the 15-20 cm depth was higher than the change from 0-5 cm to 5-10 cm. Combined, the influence of a stubble height of 34 cm and mulch quantity of 4260 kg·ha(-1) lowered the amount of erosion to 0.42 t·ha(-1), and increased the corn yield to 11900 kg·ha(-1). We determined that those were the most appropriate levels of stubble height and straw mulch for crop fields in the semi-arid regions of Northern China. PMID:27426048

  3. Effects of stubble and mulching on soil erosion by wind in semi-arid China

    NASA Astrophysics Data System (ADS)

    Cong, Peifei; Yin, Guanghua; Gu, Jian

    2016-07-01

    Soil erosion is a growing challenge for agricultural production in Northern China. To explore the effect of variation in stubble height and mulching biomass on soil erosion caused by wind, we conducted a field experiment using a quadratic rotation combination design. Results showed that the quantity of straw mulch was the dominant factor affecting soil erosion, and stubble height was of secondary importance. The soil water content in stubble and straw mulching treatments was higher than in a control treatment at 0–20 cm soil, and the tendency in the amount of soil water content was opposite to the amount of wind erosion (r = ‑0.882, n = 10, p < 0.01). The change in soil water content observed in the stubble and mulch treatments at the 15–20 cm depth was higher than the change from 0–5 cm to 5–10 cm. Combined, the influence of a stubble height of 34 cm and mulch quantity of 4260 kg·ha‑1 lowered the amount of erosion to 0.42 t·ha‑1, and increased the corn yield to 11900 kg·ha‑1. We determined that those were the most appropriate levels of stubble height and straw mulch for crop fields in the semi-arid regions of Northern China.

  4. Spatial expression of potential wind erosion threats to arable soils in the Czech Republic

    NASA Astrophysics Data System (ADS)

    Spáčilová, Bronislava; Středa, Tomáš; Thonnová, Pavlína

    2014-09-01

    Wind erosion risk strongly depends on soil surface conditions. Aridity or dryness of the climate in the Czech Republic is a typical property for Southern Moravia and Central Bohemia. The study aims to map and assess qualitatively the areas vulnerable to wind erosion using available data and intelligible methodology. The evaluation is based on the number of days when at least once a day dry condition of bare soil surface was recorded. Daily data of soil surface state from 70 climatological stations to 500 m altitude from 1981 to 2010 are used. First, soil conditions from 1st March to 30th April and from 1st September to 31st October were evaluated. Evaluation of erosion risk in May is presented separately in the second phase, because only thermophilous crops (late-sowing crops) can be affected in that time. The results show that mainly in the South and Southeast Moravia, there are areas where up to 60 days with dry soil surface in the spring and autumn occurred. Occurrence of such conditions may represent potential risk of wind erosion for arable soils and therefore potential risk for sown crops and loss of fertile soil surface which is irreplaceable for agricultural activities. The results are applicable for preparation of a concept of wind erosion control measures in the threatened regions.

  5. Effects of stubble and mulching on soil erosion by wind in semi-arid China

    PubMed Central

    Cong, Peifei; Yin, Guanghua; Gu, Jian

    2016-01-01

    Soil erosion is a growing challenge for agricultural production in Northern China. To explore the effect of variation in stubble height and mulching biomass on soil erosion caused by wind, we conducted a field experiment using a quadratic rotation combination design. Results showed that the quantity of straw mulch was the dominant factor affecting soil erosion, and stubble height was of secondary importance. The soil water content in stubble and straw mulching treatments was higher than in a control treatment at 0–20 cm soil, and the tendency in the amount of soil water content was opposite to the amount of wind erosion (r = −0.882, n = 10, p < 0.01). The change in soil water content observed in the stubble and mulch treatments at the 15–20 cm depth was higher than the change from 0–5 cm to 5–10 cm. Combined, the influence of a stubble height of 34 cm and mulch quantity of 4260 kg·ha−1 lowered the amount of erosion to 0.42 t·ha−1, and increased the corn yield to 11900 kg·ha−1. We determined that those were the most appropriate levels of stubble height and straw mulch for crop fields in the semi-arid regions of Northern China. PMID:27426048

  6. Mapping regional soil water erosion risk in the Brittany-Loire basin for water management agency

    NASA Astrophysics Data System (ADS)

    Degan, Francesca; Cerdan, Olivier; Salvador-Blanes, Sébastien; Gautier, Jean-Noël

    2014-05-01

    Soil water erosion is one of the main degradation processes that affect soils through the removal of soil particles from the surface. The impacts for environment and agricultural areas are diverse, such as water pollution, crop yield depression, organic matter loss and reduction in water storage capacity. There is therefore a strong need to produce maps at the regional scale to help environmental policy makers and soil and water management bodies to mitigate the effect of water and soil pollution. Our approach aims to model and map soil erosion risk at regional scale (155 000 km²) and high spatial resolution (50 m) in the Brittany - Loire basin. The factors responsible for soil erosion are different according to the spatial and time scales considered. The regional scale entails challenges about homogeneous data sets availability, spatial resolution of results, various erosion processes and agricultural practices. We chose to improve the MESALES model (Le Bissonnais et al., 2002) to map soil erosion risk, because it was developed specifically for water erosion in agricultural fields in temperate areas. The MESALES model consists in a decision tree which gives for each combination of factors the corresponding class of soil erosion risk. Four factors that determine soil erosion risk are considered: soils, land cover, climate and topography. The first main improvement of the model consists in using newly available datasets that are more accurate than the initial ones. The datasets used cover all the study area homogeneously. Soil dataset has a 1/1 000 000 scale and attributes such as texture, soil type, rock fragment and parent material are used. The climate dataset has a spatial resolution of 8 km and a temporal resolution of mm/day for 12 years. Elevation dataset has a spatial resolution of 50 m. Three different land cover datasets are used where the finest spatial resolution is 50 m over three years. Using these datasets, four erosion factors are characterized and

  7. Infiltration and soil erosion modelling on Lausatian post mine sites

    NASA Astrophysics Data System (ADS)

    Kunth, Franziska; Schmidt, Jürgen

    2013-04-01

    Land management of reclaimed lignite mine sites requires long-term and safe structuring of recultivation areas. Erosion by water leads to explicit soil losses, especially on heavily endangered water repellent and non-vegetated soil surfaces. Beyond that, weathering of pyrite-containing lignite burden dumps causes sulfuric acid-formation, and hence the acidification of groundwater, seepage water and surface waters. Pyrite containing sediment is detached by precipitation and transported into worked-out open cuts by draining runoff. In addition to ground water influence, erosion processes are therefore involved in acidification of surface waters. A model-based approach for the conservation of man-made slopes of post mining sites is the objective of this ongoing study. The study shall be completed by modeling of the effectiveness of different mine site recultivation scenarios. Erosion risks on man-made slopes in recultivation areas should be determined by applying the physical, raster- and event based computer model EROSION 2D/3D (Schmidt, 1991, 1992; v. Werner, 1995). The widely used erosion model is able to predict runoff as well as detachment, transport and deposition of sediments. Lignite burden dumps contain hydrophobic substances that cover soil particles. Consequently, these soils show strong water repellency, which influences the processes of infiltration and soil erosion on non-vegetated, coal containing dump soils. The influence of water repellency had to be implemented into EROSION 2D/3D. Required input data for soil erosion modelling (e.g. physical soil parameters, infiltration rates, calibration factors, etc.) were gained by soil sampling and rainfall experiments on non-vegetated as well as recultivated reclaimed mine sites in the Lusatia lignite mining region (southeast of Berlin, Germany). The measured infiltration rates on the non-vegetated water repellent sites were extremely low. Therefore, a newly developed water repellency-factor was applied to

  8. Effectiveness of soil conservation strategies on erosion in Morocco

    NASA Astrophysics Data System (ADS)

    Benmansour, Moncef; Mabit, Lionel; Moussadek, Rachid; Yassin, Mohamed; Nouira, Asmae; Zouagui, Anis; Mrabet, Rachid; Iaaich, Hamza; Hajib, Said

    2016-04-01

    - In Morocco, reducing soil erosion and land degradation is a national priority for improving soil quality and protecting downstream water quality and quantity. The combined use of Cs-137 and Be-7 techniques permit to estimate long and short term erosion and deposition magnitudes under different agro-environment and climatic conditions and then to evaluate the effectiveness of soil conservation practices. Case studies using Cs-137 and Be-7 were carried out in three Moroccan agricultural sites: Marchouch, Harchane and Oued Mellah located in Rabat, Tétouan and Chaouia-Ouardigha regions, respectively. In these sites, fallout Cs-137 measurements allowed a retrospective assessment of long term (50-60 years) soil redistribution rates while fallout Be-7 (half-life of 53 days) was used to document short term soil erosion associated with rainfall events for different tillage systems and land uses. Long term soil erosion rates of the three regions evaluated by the Cs-137 method, ranged from 8 to 58 t/ha/yr. Mostly located in the upslope part of the fields, the eroding zones represented more than 70% of the total area. For the experimental sites in Rabat and Tétouan, the results obtained using Be-7 indicated that soil loss has been reduced significantly under no-till as compared to conventional tillage. Indeed, soil erosion rates were lowered by 50% for the Marchouch site and by 40% for the Harchane site. Concerning the Oued Mellah watershed, the results highlighted that high density Atriplex plantations have reduced soil loss by approximately 60 to 80%, while for the site under fruit plantations and cereals, soil erosion has been decreased by 58%.

  9. RWEQ - Wind erosion predictions for variable soil roughness conditions

    NASA Astrophysics Data System (ADS)

    de Oro, Laura A.; Colazo, Juan C.; Buschiazzo, Daniel E.

    2016-03-01

    The soil surface roughness is a main factor in all wind erosion prediction models, including the Revised Wind Erosion Equation (RWEQ). The objective of this study was to test the erodibility of two typical soils of the semiarid Argentinean Pampas under three different tillage conditions (compared to a flat surface) at three wind velocities using a wind tunnel and to evaluate the performance of the RWEQ model. Results showed that all rough surfaces were less eroded by wind than a flat surface (FS) in both soils and all wind velocities. An exception was LB (lister-bedder) in the Haplustoll that showed similar erosion than FS. Wind erosion increased rapidly above 16.5 m s-1 wind velocity in all tillage conditions. The relative wind erosion (RE) calculated with the RWEQ (K‧ factor) fitted well with measured RE, except for K‧ < 0.1 (rougher surface) where the measured RE were much higher than the predicted. More than 70% of RE variability was explained by the oriented roughness (Kr) in both soils. The aforementioned indicates that Kr can be used instead of K‧ (a value that contains both, Kr and the random roughness - Crr factors) to predict wind erosion with RWEQ in the studied soils. Absolute wind erosion amounts predicted with RWEQ fitted well with measured data only for DT, mainly at low wind velocity. For the other tillage tools, the model did not apply well as it underestimated the erosion for the rougher soil surface condition (LB) and overestimated it for the less rough surface (DH).

  10. Effects of soil management techniques on soil water erosion in apricot orchards.

    PubMed

    Keesstra, Saskia; Pereira, Paulo; Novara, Agata; Brevik, Eric C; Azorin-Molina, Cesar; Parras-Alcántara, Luis; Jordán, Antonio; Cerdà, Artemi

    2016-05-01

    Soil erosion is extreme in Mediterranean orchards due to management impact, high rainfall intensities, steep slopes and erodible parent material. Vall d'Albaida is a traditional fruit production area which, due to the Mediterranean climate and marly soils, produces sweet fruits. However, these highly productive soils are left bare under the prevailing land management and marly soils are vulnerable to soil water erosion when left bare. In this paper we study the impact of different agricultural land management strategies on soil properties (bulk density, soil organic matter, soil moisture), soil water erosion and runoff, by means of simulated rainfall experiments and soil analyses. Three representative land managements (tillage/herbicide/covered with vegetation) were selected, where 20 paired plots (60 plots) were established to determine soil losses and runoff. The simulated rainfall was carried out at 55mmh(-1) in the summer of 2013 (<8% soil moisture) for one hour on 0.25m(2) circular plots. The results showed that vegetation cover, soil moisture and organic matter were significantly higher in covered plots than in tilled and herbicide treated plots. However, runoff coefficient, total runoff, sediment yield and soil erosion were significantly higher in herbicide treated plots compared to the others. Runoff sediment concentration was significantly higher in tilled plots. The lowest values were identified in covered plots. Overall, tillage, but especially herbicide treatment, decreased vegetation cover, soil moisture, soil organic matter, and increased bulk density, runoff coefficient, total runoff, sediment yield and soil erosion. Soil erosion was extremely high in herbicide plots with 0.91Mgha(-1)h(-1) of soil lost; in the tilled fields erosion rates were lower with 0.51Mgha(-1)h(-1). Covered soil showed an erosion rate of 0.02Mgha(-1)h(-1). These results showed that agricultural management influenced water and sediment dynamics and that tillage and herbicide

  11. Soil Erosion Study through Simulation: An Educational Tool.

    ERIC Educational Resources Information Center

    Huber, Thomas P.; Falkenmayer, Karen

    1987-01-01

    Discusses the need for education about soil erosion and advocates the use of the Universal Soil Loss Equation (USLE) to show the impacts of human and natural action on the land. Describes the use of a computer simulated version of the USLE in several environmental and farming situations. (TW)

  12. Soil erosion on upland areas by rainfall and overland flow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion in agricultural watersheds is a systemic problem that has plagued mankind ever since the practice of agriculture began some 9,000 years ago. It is a worldwide problem, the severity of which varies from location to location depending on weather, soil type, topography, cropping practices,...

  13. Plume Mitigation: Soil Erosion and Lunar Prospecting Sensor Project

    NASA Technical Reports Server (NTRS)

    Metzger, Philip T.

    2014-01-01

    Demonstrate feasibility of the simplest, lowest-mass method of measuring density of a cloud of lunar soil ejected by rocket exhaust, using new math techniques with a small baseline laser/camera system. Focus is on exploring the erosion process that occurs when the exhaust plume of a lunar rocket impacts the regolith. Also, predicting the behavior of the lunar soil that would be blasted from a lunar landing/launch site shall assist in better design and protection of any future lunar settlement from scouring of structures and equipment. NASA is gathering experimental data to improve soil erosion models and understand how lunar particles enter the plume flow.

  14. Erosion: Wind

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion refers to the detachment, transport and deposition of sediment by wind. It is a dynamic, physical process where loose, dry, bare soils are transported by strong winds. Wind erosion is a soil degrading process that affects over 500 million ha of land worldwide and creates between 500 an...

  15. Effect of Rainfall-moving Direction on Slope Runoff and Soil Erosion

    NASA Astrophysics Data System (ADS)

    Wang, F.; Ran, Q.

    2014-12-01

    Although topographic characteristics is one of the factors controlling hillslope erosion, the current understanding of the impacts of rainfall-moving direction is far from thorough. In this study, a series of laboratory experiments were conducted to evaluate the effect of rainfall-moving direction and rainfall intensity on runoff generation and soil erosion.3D laser scanner were also used to monitor the slope surface changing. Runoff and sediment samples were taken at 1-min intervals. The results showed that there is one peak sediment concentration in upstream-moving rainfall events but two in downstream-moving rainfall events. Surface sealing greatly affected the sediment grading at the beginning of runoff, which results in less soil erosion. Because of the fully developed crust, the discharge peak occurred after the erosion peak in upstream-moving rainfall events, while two peaks occurred at the same time in downstream conditions. The erosion of downstream moving rainfall events were higher than upstream moving rainfall events under same condition. This study give a better understanding of hillslope erosion and crust development, which will improve the technology of water and soil conservation and numerical erosion simulation

  16. 7 CFR 610.13 - Equations for predicting soil loss due to wind erosion.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Equations for predicting soil loss due to wind erosion... Erosion Prediction Equations § 610.13 Equations for predicting soil loss due to wind erosion. (a) The equation for predicting soil loss due to wind in the Wind Erosion Equation (WEQ) is E = f(IKCLV)....

  17. 7 CFR 610.13 - Equations for predicting soil loss due to wind erosion.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Equations for predicting soil loss due to wind erosion... Erosion Prediction Equations § 610.13 Equations for predicting soil loss due to wind erosion. (a) The equation for predicting soil loss due to wind in the Wind Erosion Equation (WEQ) is E = f(IKCLV)....

  18. Soil erosion from two small construction sites, Dane County, Wisconsin

    USGS Publications Warehouse

    Owens, David W.; Jopke, Peter; Hall, David W.; Balousek, Jeremy; Roa, Aicardo

    2000-01-01

    Soil erosion from construction sites has long been identified as a significant source of sediment and other suspended solids in runoff in many parts of the United States (Hagman and others, 1980; Yorke and Herb, 1976: Becker and others, 1974). In some states, such as Wisconsin, sediment has been identified as the number one pollutant (by volume) of surface waters (Wisconsin Depart- ment of Natural Resources, 1994). Because numerous water-quality problems in streams are associated with excessive sedimentation, Federal and state regulations requiring erosion-control measures at construction sites larger than 5 acres have been developed and implemented from the 1970's to the present. During the 1990's, excessive erosion and sediment production associated with small residential and commercial sites of less than 5 acres has been increasingly recognized for its effects on streams not only erosion from individual sites but also erosion from discontinuous groups of sites within a stream basin.

  19. Soil dynamics and accelerated erosion: a sensitivity analysis of the LPJ Dynamic vegetation model

    NASA Astrophysics Data System (ADS)

    Bouchoms, Samuel; Van Oost, Kristof; Vanacker, Veerle; Kaplan, Jed O.; Vanwalleghem, Tom

    2013-04-01

    It is widely accepted that humans have become a major geomorphic force by disturbing natural vegetation patterns. Land conversion for agriculture purposes removes the protection of soils by the natural vegetation and leads to increased soil erosion by one to two orders of magnitude, breaking the balance that exists between the loss of soils and its production. Accelerated erosion and deposition have a strong influence on evolution and heterogeneity of basic soil characteristics (soil thickness, hydrology, horizon development,…) as well as on organic matter storage and cycling. Yet, since they are operating at a long time scale, those processes are not represented in state-of-art Dynamic Global Vegetation Models, which is a clear lack when exploring vegetation dynamics over past centuries. The main objectives of this paper are (i) to test the sensitivity of a Dynamic Global Vegetation Model, in terms of NPP and organic matter turnover, variations in state variables in response to accelerated erosion and (ii) to assess the performance of the model under the impact of erosion for a case-study in Central Spain. We evaluated the Lund-Postdam-Jena Dynamic Vegetation Model (LPJ DVGM) (Sitch et al, 2003) which simulates vegetation growth and carbon pools at the surface and in the soil based on climatic, pedologic and topographic variables. We assessed its reactions to changes in key soil properties that are affected by erosion such as texture and soil depth. We present the results of where we manipulated soil texture and bulk density while keeping the environmental drivers of climate, slope and altitude constant. For parameters exhibiting a strong control on NPP or SOM, a factorial analysis was conducted to test for interaction effects. The simulations show an important dependence on the clay content, especially for the slow cycling carbon pools and the biomass production, though the underground litter seems to be mostly influenced by the silt content. The fast cycling C

  20. Remontant erosion in desert soils of Tamaulipas, México.

    NASA Astrophysics Data System (ADS)

    Rivera-Ortiz, P.; Andrade-Limas, E.; De la Garza-Requena, F.; Castro-Meza, B.

    2012-04-01

    REMONTANT EROSION IN DESERT SOILS OF TAMAULIPAS MÉXICO Rivera-Ortiz, P.1; Andrade-Limas, E.1; De la Garza-Requena, F.1 and Castro-Meza, B.1 1Facultad de Ingeniería y Ciencias, Universidad Autónoma de Tamaulipas, México The degradation of soil reduces the capacity of soils to produce food and sustain life. Erosion is one of the main types of soil degradation. Hydric erosion of remontant type can occur in soils located close to the channel of a river through the expansion of a gully that begins as a fluvial incision over the ravine of one side of the river. The incision takes place at the point of greatest flow of runoff from areas adjacent to empty into the river. The depth of the incision causes the growth of the gully by collapse to move their heads back, upstream. The soil loss by remontant erosion on land use in agriculture and livestock was estimated in order to understand the evolution of gullies formed by this type of erosion. Through measurements on satellite images and GPS (Global Positioning System) two gullies, developed on alluvial soils which drain into the river Chihue, were studied. The investigation was conducted during 2003 to 2010 period in the municipality of Jaumave, Tamaulipas, in northeastern Mexico. Soil loss in gullies developed by remontant erosion was large and it was caused by soil collapse and drag of soil on the headers. The estimated loss of soil by remontant erosion was 3500 t in the deeper gully during 2010 and nearly 1200 t per year in the period 2003-2009. New sections of gully of about 20 m length, with more than 3 m deep and up to 13 m wide, were formed each year. This degradation has significantly reduced the productive surface of soil that for many years has been used to the cultivation of maize (Zea mays) and beans (Phaseolus vulgaris) as well as pasture production.

  1. Modeling of technical soil-erosion control measures and its impact on soil erosion off-site effects within urban areas

    NASA Astrophysics Data System (ADS)

    Dostal, Tomas; Devaty, Jan

    2013-04-01

    soil-erosion control measures induced strong change in overall amount of eroded/deposited material as well as spatial erosion/deposition patterns within the settlement areas. Validation of modeled scenarios and effects on measured data was not possible as no real runoff event was recorded in the target area so the conclusions were made by comparing the different modeled scenarios. Advantages and disadvantages of used approach to simulate technical soil-erosion conservation measures are evaluated and discussed as well as the impact of use of high-resolution elevation data on the intensity and spatial distribution of soil erosion and deposition. Model approved ability to show detailed distribution of damages over target urban area, which is very sensitive for off-site effects of surface runoff, soil erosion and sediment transport and also high sensitivity to input data, especially to DEM, which affects surface runoff pattern and therefore intensity of harmful effects. Acknowledgement: This paper has been supported by projects: Ministry of the interior of the CR VG 20122015092, and project NAZV QI91C008 TPEO.

  2. Soil erosion on vineyards: impacts on vine performances

    NASA Astrophysics Data System (ADS)

    Degan, Francesca; Salvador-Banes, Sébastien; Cerdan, Olivier; Goulet, Etienne; Le Duc, Lionel

    2014-05-01

    Many agricultural practices increase soil degradation processes. The measurement of the effects of such practices helps for the management of constraints and ensures the stability of agricultural production. In viticulture, soil is one of the components that define the specificity and quality of wine. Chemical and physical soil properties indeed exert a strong influence on vine performances. However, the precise influences of soil properties, such as rock fragments, clay or lime contents, soil depth or mineral content are subjected to debate. Actually, vine performances derive also from climate and vintage, viticulture and winemaking techniques and plant genetic. Nerveless, soil erosion can significantly change the root growing zone properties and therefore the vine responses. In fact viticulture is the agricultural production that is the most prone to erosion, with an average rate of 12 t.ha -1.yr-1 in the European context (Cerdan et al., 2010). The soil's capacities to support crop growth, without resulting in soil degradation, need to be brought under control, to improve environmental sustainability and minimize in-site and off-site impacts. The aim of this study is to better quantify the effect of soil erosion in vineyards on soil parameters (such as available water content) that exert a key role in the specificity of viticultural terroirs. Two study areas are considered in Corsica and in the Loire Valley. Our approach is divided into three steps. Firstly, the identification and the mapping of soil properties that have an impact over vine performances, using digital soil mapping techniques and pedotransfer functions. The soil characteristics are identified by field survey at two spatial resolutions: the field and landscape. In the same study areas, the erosion dynamics is assessed. Various techniques are employed such as: 137Cs activities, spatial distribution of copper and stock unearthing. In order to comprehend erosion dynamics and evolutions, the third step

  3. Runoff generation and soil erosion processes after clear-cuttings

    NASA Astrophysics Data System (ADS)

    Iroume, A.; Mohr, C. H.; Bronstert, A.; Huber, A.

    2012-12-01

    Timber harvesting by large scale clear-cut is known to impose environmental impact including severe disturbance of the soil-hydraulic properties which in turn intensify surface runoff and soil erosion in both frequency and magnitude. However, it remains unanswered if such clear-cut harvest areas act rather as sources or sinks for runoff and soil erosion and whether such behaviour is steady or dynamically alternating. For this purpose, 92 small scale rainfall simulations of different intensities were carried out under pine plantation conditions and on two clear-cut harvest areas of different age in the Chilean Coastal Range. Non-parametrical Random Forest statistical models were set up to quantify the impact of environmental variables on the hydrological and erosion response. The plot-scale responses were linked to observations at the catchment outlets. Against all expectations, infiltration rates slightly increased after logging while runoff initiated fastest and generated highest infiltration excess rates under plantation forest floor regardless of the applied rainfall intensity. Exceeding a threshold rainfall intensity of 20 mm/h, the clear-cut areas started to act as a source for both runoff and erosion after connectivity established while they remained a sink under lower applied rainfall intensities. Post-logging soil erosion increased by two orders of magnitude compared with unlogged conditions highlighting the importance of reforestation immediately after the timber harvest. The results suggest that surface runoff connectivity by overcoming microtopography restrictions, preferential flow along recent and former root systems and water repellence control runoff generation and soil erosion processes in such environments. Fast hydrological response to rainfall, sediment-discharge-hystereses and enhanced post-logging groundwater recharge at catchment scale support our interpretation. The persistent impact of timber harvest by clear-cut practice implies that inter

  4. Soil erosion and land degradation in the Highlands of Jordan

    NASA Astrophysics Data System (ADS)

    Khresat, Saeb

    2013-04-01

    The Highlands of Jordan has a Mediterranean type of climate characterized by hot dry summers and cold wet winters. Unsustainable land use practices, recurrent droughts and climate change are the main causes of land degradation in the Highlands area of Jordan. Unsustainable land use practices include improper plowing, inappropriate rotations, inadequate or inexistent management of plant residues, overgrazing of natural vegetation, forest cutting, land fragmentation and over-pumping of groundwater. In addition, Jordan's rapid population growth (2.8% per year) is exerting considerable pressure upon its limited arable land through uncontrolled and random urbanization activities. Water erosion is the most widespread Land degradation type in the country. It greatly increases on slopes where the vegetation cover is (seasonally) reduced. It is further aggravated by a loss of soil structure and reduced infiltration rates. Wind erosion occurs most frequently in the arid and semi-arid portions of the southern Highlands, especially in areas with sandy or loamy soils. Rangeland degradation is the second most widespread land degradation type that is driven by overgrazing. The impact of overgrazing on the vegetation is evident from the excessive uprooting of the green matter (grass and bushes), leading to reduced seeding, reduced regeneration, and the consequent loss of plant cover which make the soil more susceptible to water and wind erosion. It is estimated that about 41 percent of Jordan's total land area is characterized as degraded of which 22 percent of the total land mass is classified as moderately degraded and agricultural productivity is greatly reduced. Observed aspects of land degradation include the recession of forest areas, high rate of erosion by water (formation of rills and gullies), expansion of urbanized area, reduction in soil organic matter and soil structure deterioration. Implementation of soil erosion control measures such as contour cultivation

  5. Soil erosion by water - model concepts and application

    NASA Astrophysics Data System (ADS)

    Schmidt, Juergen

    2010-05-01

    Soil erosion is not a continuous process but the result of isolated surface runoff events, whose erosional effects are determined by numerous temporally and spatially varying variables. Thus the monitoring of soil loss by direct observation is extremely limited with respect to space and time. Usually observation plots cover an area of less than 100 m2 and the observation period is less than 10 years. In order to estimate soil losses by water erosion for others than empirically observable conditions, mathematical models are needed, which are able to describe the interaction of the different physical mechanisms involved either statistically or on the basis of physical algorithms. Such models are absolutely essential for risk prognoses on catchment and regional scale. Besides the aspect of soil conservation the delivery of sediments and sediment bound pollutants into surface water bodies are of increasing relevance in this context. Based on an exemplary selection of existing water erosion models this contribution aims to give an overview over different mathematical approaches used for the description of particle detachment, transport and deposition of soil particles. According to the chronology in the development of soil erosion models empirical algorithms will be presented first based on the USLE approach. However, since purely empirical models like USLE are limited to the estimation of annual soil loss further attempts in soil erosion modelling are focussed on event based estimations considering the fact that soil erosion is not a continuous process but the result of isolated runoff events. One of the first models of this type was CREAMS using physically based algorithms in combination with empirical ones in order to describe the basic erosion processes. Today there are diverse soil erosion models available following in principle the CREAMS concept but using different algorithms in detail. Concerning particle detachment, transport and deposition alternative

  6. Tracing soil erosion impacts on soil organisms using 137Cs and soil nematodes

    NASA Astrophysics Data System (ADS)

    Baxter, Craig; Rowan, John S.; McKenzie, Blair M.; Neilson, Roy

    2014-05-01

    The application of environmental radionuclides in soil tracing and erosion studies is now well established in geomorphology. Sediment and erosion-tracing studies are undertaken for a range of purposes in the earth sciences but until now few studies have used the technique to answer biological questions. An experiment was undertaken to measure patterns of soil loss and gain over 50 years, effectively calculating a field-scale sediment budget, to investigate soil erosion relationships between physical and biological soil components. Soil nematodes were identified as a model organism, a ubiquitous and abundant group sensitive to disturbance and thus useful indicator taxa of biological and physico-chemical changes. A field site was selected at the James Hutton Institute's experimental Balruddery Farm in NE Scotland. 10 metre-resolution topographical data was collected with differential GPS. Based on these data, a regular 30 m-resolution sampling grid was constructed in ArcGIS, and a field-sampling campaign undertaken. 104 soil cores (~50 cm-deep) were collected with a percussion corer. Radio-caesium (137Cs) activity concentrations were measured using high-purity germainum gamma-ray spectroscopy, and 137Cs areal activities derived from these values. Organic matter content by loss on ignition and grain-size distribution by laser granulometry were also measured. Additional samples were collected to characterise the soil nematode community, both for abundance and functional (trophic) composition using a combination of low-powered microscopy and molecular identification techniques (dTRFLP). Results were analysed with ArcGIS software using the Spatial Analyst package. Results show that spatial relationships between physical, chemical and biological parameters were complex and interrelated. Previous field management was found to influence these relationships. The results of this experiment highlight the role that soil erosion processes play in medium-term restructuring of the

  7. Using 137 Cs measurements to investigate the influence of erosion and soil redistribution on soil properties.

    PubMed

    Du, P; Walling, D E

    2011-05-01

    Information on the interaction between soil erosion and soil properties is an important requirement for sustainable management of the soil resource. The relationship between soil properties and the soil redistribution rate, reflecting both erosion and deposition, is an important indicator of this interaction. This relationship is difficult to investigate using traditional approaches to documenting soil redistribution rates involving erosion plots and predictive models. However, the use of the fallout radionuclide (137)Cs to document medium-term soil redistribution rates offers a means of overcoming many of the limitations associated with traditional approaches. The study reported sought to demonstrate the potential for using (137)Cs measurements to assess the influence of soil erosion and redistribution on soil properties (particle size composition, total C, macronutrients N, P, K and Mg, micronutrients Mn, Mo, Fe, Cu and Zn and other elements, including Ti and As). (137)Cs measurements undertaken on 52 soil cores collected within a 7 ha cultivated field located near Colebrooke in Devon, UK were used to establish the magnitude and spatial pattern of medium-term soil redistribution rates within the field. The soil redistribution rates documented for the individual sampling points within the field ranged from an erosion rate of -12.9 t ha(-1) yr(-1) to a deposition rate of 19.2 t ha(-1) yr(-1). Composite samples of surface soil (0-5 cm) were collected immediately adjacent to each coring point and these samples were analysed for a range of soil properties. Individual soil properties associated with these samples showed significant variability, with CV values generally lying in the range 10-30%. The relationships between the surface soil properties and the soil redistribution rate were analysed. This analysis demonstrated statistically significant relationships between some soil properties (total phosphorus, % clay, Ti and As) and the soil redistribution rate, but for

  8. 7 CFR 610.12 - Equations for predicting soil loss due to water erosion.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Equations for predicting soil loss due to water... ASSISTANCE Soil Erosion Prediction Equations § 610.12 Equations for predicting soil loss due to water erosion. (a) The equation for predicting soil loss due to erosion for both the USLE and the RUSLE is A = R ×...

  9. 7 CFR 610.12 - Equations for predicting soil loss due to water erosion.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Equations for predicting soil loss due to water... ASSISTANCE Soil Erosion Prediction Equations § 610.12 Equations for predicting soil loss due to water erosion. (a) The equation for predicting soil loss due to erosion for both the USLE and the RUSLE is A = R ×...

  10. 7 CFR 610.12 - Equations for predicting soil loss due to water erosion.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Equations for predicting soil loss due to water... ASSISTANCE Soil Erosion Prediction Equations § 610.12 Equations for predicting soil loss due to water erosion. (a) The equation for predicting soil loss due to erosion for both the USLE and the RUSLE is A = R ×...

  11. Assessment of Soil Erosion in a Cultivated Landscape Using Repeated Measurements of 137Cs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion is a major environmental concern with the potential to severely impact soil and water quality. Assessments of soil erosion are normally carried out using model predictions. Cesium-137 can be used to provide estimates of soil erosion at a landscape scale, and it remains the best tool to ...

  12. Modelling soil erosion in a clayey, subsurface-drained agricultural field with a three-dimensional FLUSH model

    NASA Astrophysics Data System (ADS)

    Warsta, Lassi; Taskinen, Antti; Koivusalo, Harri; Paasonen-Kivekäs, Maija; Karvonen, Tuomo

    2013-08-01

    Soil erosion is an important environmental issue in agricultural areas of northern Europe where clayey soils are prevalent. Clayey soils are routinely subsurface drained to accelerate drainage which creates an additional discharge route for suspended sediment. Previously, assessment of the sediment load from clayey fields has been difficult, because process-based models were only able to simulate sediment loads via surface runoff. A new distributed, process-based erosion model was developed and incorporated into the FLUSH modelling system to fulfil this void. The model facilitates simulation of spatially distributed soil erosion on the field surface and sediment loads via surface runoff and subsurface drainflow. Soil erosion on the field surface is simulated with the two-dimensional sediment continuity equation coupled with hydraulic and rain drop splash erosion, sediment settling, and transport capacity processes. Subsurface sediment transport in macropores is described with the three-dimensional advection-dispersion equation. The model was applied to a clayey, subdrained field section (∼3.6 ha) in southern Finland. The results demonstrated the capability of the model to simulate soil erosion and sediment transport in terms of the match between the measured (2669 kg ha-1) and modelled (2196 kg ha-1) sediment loads via surface runoff and the measured (2937 kg ha-1) and modelled (2245 kg ha-1) loads via drainflow during the validation period of 7 months. The model sensitivity analysis pointed out the importance of the flow model parameters in simulation of soil erosion through their control on the division of total runoff into surface runoff and drainflow components. The key parameters in the erosion model were those that affected hydraulic and splash erosion rates. The model application in the experimental field suggested that both hydraulic and splash erosion were the factors behind the sediment losses during the growing season and early autumn, whereas high

  13. A GIS-based Framework for Examining the Effects of Water-Driven Erosion on Soil Biogeochemical Cycling

    NASA Astrophysics Data System (ADS)

    Abban, B. K.; Papanicolaou, T.; Wacha, K.; Wilson, C. G.

    2014-12-01

    Soil erosion has long been identified as one of the key mechanisms affecting biogeochemical processes in the soil, through the transport and delivery of carbon and nutrients adsorbed to soil particles in the soil active layer. However, most biogeochemical models treat soil erosion contributions simplistically and lack the capacity to accurately account for the mechanisms that control soil erosion and deposition on the landscape. This stems from the fact that the majority of the biogeochemical models have traditionally been employed on landscapes where lateral and downslope fluxes due to soil erosion have been less significant compared to other vertical fluxes and processes occurring at a fixed location on the landscape. In intensely managed landscapes, however, this may not be the case since land management practices such as tillage and exposed land cover can lead to copious amounts of erosion on the landscape. Therefore, to better understand the role of soil erosion on soil biogeochemical cycling in IMLs, we present a framework for simulating the spatiotemporal effects of soil erosion and deposition on soil biogeochemical cycling. We focus specifically on tillage- and runoff-induced erosion since these are prevalent in IMLs. The framework employs a geospatial approach that loosely couples a GIS-based upland water erosion model, GeoWEPP, with a soil biogeochemistry model, Century, to predict downslope and lateral fluxes of soil erosion and the resultant impacts on soil biogeochemical cycling. The use of a geospatial approach allows us to better capture the effects of topography, soil type, land use/land cover, and climate on soil erosion fluxes as well as soil biogeochemical cycling. The spatiotemporal resolution of the framework makes it particularly beneficial for identifying hotspots in fields and hot moments at scales ranging from daily to annual time scales. We employ the framework to study the monthly redistribution of soil organic carbon over the course of a

  14. Can conservation agriculture reduce the impact of soil erosion in northern Tunisia ?

    NASA Astrophysics Data System (ADS)

    Bahri, Haithem; Annabi, Mohamed; Chibani, Roukaya; Cheick M'Hamed, Hatem; Hermessi, Taoufik

    2016-04-01

    Mediterranean countries are prone to soil erosion, therefore Tunisia, with Mediterranean climate, is threatened by water erosion phenomena. In fact, 3 million ha of land is threatened by erosion, and 50% is seriously affected. Soils under conservation agriculture (CA) have high water infiltration capacities reducing significantly surface runoff and thus soil erosion. This improves the quality of surface water, reduces pollution from soil erosion, and enhances groundwater resources. CA is characterized by three interlinked principles, namely continuous minimum mechanical soil disturbance, permanent organic soil cover and diversification of crop species grown in sequence or associations. Soil aggregate stability was used as an indicator of soil susceptibility to water erosion. Since 1999, In Tunisia CA has been introduced in rainfed cereal areas in order to move towards more sustainable agricultural systems. CA areas increased from 52 ha in 1999 to 15000 ha in 2015. The objective of this paper is to study the effect of CA on soil erosion in northern Tunisia. Soil samples were collected at 10 cm of depth from 6 farmers' fields in northern Tunisia. Conventional tillage (CT), CA during less than 5 years (CA<5 years) and CA during more than 5 years (CA>5 years) have been practiced in each farmers field experiment of wheat crop. Soil aggregate stability was evaluated according to the method described by Le Bissonnais (1996), results were expressed as a mean weight diameter (MWD); higher values of MWD indicate higher aggregate stability. Total organic carbon (TOC) was determined using the wet oxidation method of Walkley-Black. A significant increase in SOC content was observed in CA>5years (1.64 %) compared to CT (0.97 %). This result highlights the importance of CA to improve soil fertility. For aggregate stability, a net increase was observed in CA compared to CT. After 5 years of CA the MWD was increased by 16% (MWD=1.8 mm for CT and MWD=2.1 mm for CA<5years). No

  15. Soil erosion in river basins of Georgia

    NASA Astrophysics Data System (ADS)

    Gogichaishvili, G. P.

    2016-06-01

    The area of cultivated lands in western and eastern Georgia comprises 28-40 and 29-33% of the total catchment areas, respectively. Eroded arable soils in Georgia occupy 205700 ha, i.e. 30.5% of the total plowland area, including 110500 ha (16.4%) of slightly eroded soils, 74400 ha (11%) of moderately eroded soils, and 20800 ha (3.1%) of strongly eroded soils. The maximum denudation rate in catchments of western Georgia reaches 1.0 mm/yr. The minimum denudation (0.01 mm/yr.) is typical of river catchments in southern Georgia. The mean annual soil loss from plowed fields in western Georgia reaches 17.4 t/ha and exceeds the soil loss tolerance by nearly four times. In eastern Georgia, it is equal to 10.46 t/ha and exceeds the soil loss tolerance by 2.5 times. In southern Georgia, the mean annual soil loss from plowed fields is as low as 3.08 t per ha, i.e., much lower than the soil loss tolerance.

  16. Carbon redistribution during interrill erosion in subtropical forests: Effects of leaf litter diversity and soil fauna

    NASA Astrophysics Data System (ADS)

    Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Scholten, Thomas

    2016-04-01

    Soil erosion is crucial for degradation of carbon (C) from their pools in the soil. If C of the eroded sediment and runoff are not only related to soil pools but also resulting additively from decomposition of litter cover, the system gets more complex. The role of these amounts for C cycling in a forest environment is not yet known properly and thus, the aim of this study was to investigate the role of leaf litter diversity, litter cover and soil fauna on C redistribution during interrill erosion. We established 96 runoff plots that were deployed with seven domestic leaf litter species resulting in none species (bare ground), 1-species, 2-species and 4-species mixtures. Every second runoff plot was equipped with a fauna extinction feature to investigate the role of soil meso- and macrofauna. Erosion processes were initiated using a rainfall simulator at two time steps (summer 2012 and autumn 2012) to investigate the role of leaf litter decomposition on C redistribution. C fluxes during 20 min rainfall simulation were 99.13 ± 94.98 g/m². C fluxes and C contents both were affected by soil fauna. C fluxes were higher with presence of soil fauna due to loosening and slackening of the soil surface rather than due to faster decomposition of leaves. In contrast, C contents were higher in the absence of soil fauna possibly resulting from a missing dilution effect in the top soil layer. Leaf litter diversity did not affect C fluxes, but indirectly affected C contents as it increased the soil fauna effect with higher leaf litter diversity due to superior food supply. Initial C contents in the soil mainly determined those of the eroded sediment. For future research, it will be essential to introduce a long-term decomposition experiment to get further insights into the processes of C redistribution.

  17. Experimental research of soil erosion using laboratory rainfall simulator

    NASA Astrophysics Data System (ADS)

    Laburda, Tomáš; Schwarzová, Pavla; Krása, Josef

    2015-04-01

    Soil erosion has been an important part of research at the Department of Irrigation, Drainage and Landscape Engineering, Czech Technical University in Prague since the 50s of the 20th century. Bigger emphasis was put later on practical methods resulting in acquisition of laboratory rainfall simulator in 1999. This article compares data from simulations done at the laboratory rainfall simulator which is used for experimental measurement of rainfall-runoff processes on soil samples (typical soil type groups) from agriculture land in the Czech Republic. Total 10 soil sets have been tested within 255 simulations (247 rainfall-runoff hours in total) from 2002 to 2014. These soil sets cover wide range of soil types from silty clay loam to sandy loam soils or from impervious to pervious soils. Setting values of rainfall intensity (40 to 60 mm/hr), inclination (longitudinal slope from 4° to 8°) and initial condition of surface runoff (crusted or loosened) present primary parameters of every experiment. On the basis of different combinations of setting, 2 representative evaluation states of the minimum (min LC) and maximum (max LC) load conditions were established. The most important data obtained at the Simulator are soil moisture content, progression of surface runoff, soil loss and infiltration. Results clearly show dependence of initial moisture content on physical properties, when impervious soils with high fraction of clay reach over 30 % wt., pervious soils with high fraction of sand achieve initial average moisture content only about 20 % wt. Results of steady-state values of surface runoff and soil loss for minimum and maximum load conditions and its ratio show that highest increase of values due to higher load conditions reach silt loamy soil (Horomerice), silt clay loamy soil (Klapy) and loamy soil (Vsetaty), while the lowest increase reach silt loamy soil (Trebsin I) and sandy loamy soil (Trebesice I). General trend in all cases is obviously to increase both

  18. Dust and nutrient enrichment by wind erosion from Danish soils in dependence of tillage direction

    NASA Astrophysics Data System (ADS)

    Mohammadian Behbahani, Ali; Fister, Wolfgang; Heckrath, Goswin; Kuhn, Nikolaus J.

    2016-04-01

    Wind erosion is a selective process, which promotes erosion of fine particles. Therefore, it can be assumed that increasing erosion rates are generally associated with increasing loss of dust sized particles and nutrients. However, this selective process is strongly affected by the orientation and respective trapping efficiency of tillage ridges and furrows. Since tillage ridges are often the only protection measure available on poorly aggregated soils in absence of a protective vegetation cover, it is very important to know which orientation respective to the dominant wind direction provides best protection. This knowledge could be very helpful for planning erosion protection measures on fields with high wind erosion susceptibility. The main objective of this study, therefore, was to determine the effect of tillage direction on dust and nutrient mobilization by wind, using wind tunnel simulations. In order to assess the relationship between the enrichment ratio of specific particle sizes and the amount of eroded nutrients, three soils with loamy sand texture, but varying amounts of sand-sized particles, were selected. In addition, a soil with slightly less sand, but much higher organic matter content was chosen. The soils were tested with three different soil surface scenarios - flat surface, parallel tillage, perpendicular tillage. The parallel tillage operation experienced the greatest erosion rates, independent of soil type. Particles with D50 between 100-155 μm showed the greatest risk of erosion. However, due to a greater loss of dust sized particles from perpendicularly tilled surfaces, this wind-surface arrangement showed a significant increase in nutrient enrichment ratio compared to parallel tillage and flat surfaces. The main reason for this phenomenon is most probably the trapping of larger particles in the perpendicular furrows. This indicates that the highest rate of soil protection does not necessarily coincide with lowest soil nutrient losses and

  19. Understanding soil erosion impacts in temperate agroecosystems: bridging the gap between geomorphology and soil ecology

    NASA Astrophysics Data System (ADS)

    Baxter, C.; Rowan, J. S.; McKenzie, B. M.; Neilson, R.

    2013-04-01

    Soil is a key asset of natural capital, providing a myriad of goods and ecosystem services that sustain life through regulating, supporting and provisioning roles, delivered by chemical, physical and biological processes. One of the greatest threats to soil is accelerated erosion, which raises a natural process to unsustainable levels, and has downstream consequences (e.g. economic, environmental and social). Global intensification of agroecosystems is a major cause of soil erosion which, in light of predicted population growth and increased demand for food security, will continue or increase. Elevated erosion and transport is common in agroecosystems and presents a multi-disciplinary problem with direct physical impacts (e.g. soil loss), other less tangible impacts (e.g. loss of ecosystem productivity), and indirect downstream effects that necessitate an integrated approach to effectively address the problem. Climate is also likely to increase susceptibility of soil to erosion. Beyond physical response, the consequences of erosion on soil biota have hitherto been ignored, yet biota play a fundamental role in ecosystem service provision. To our knowledge few studies have addressed the gap between erosion and consequent impacts on soil biota. Transport and redistribution of soil biota by erosion is poorly understood, as is the concomitant impact on biodiversity and ability of soil to deliver the necessary range of ecosystem services to maintain function. To investigate impacts of erosion on soil biota a two-fold research approach is suggested. Physical processes involved in redistribution should be characterised and rates of transport and redistribution quantified. Similarly, cumulative and long-term impacts of biota erosion should be considered. Understanding these fundamental aspects will provide a basis upon which mitigation strategies can be considered.

  20. Ecological site-based assessments of wind and water erosion: informing accelerated soil erosion management in rangelands

    USGS Publications Warehouse

    Webb, Nicholas P.; Herrick, Jeffrey E.; Duniway, Michael C.

    2014-01-01

    Accelerated soil erosion occurs when anthropogenic processes modify soil, vegetation or climatic conditions causing erosion rates at a location to exceed their natural variability. Identifying where and when accelerated erosion occurs is a critical first step toward its effective management. Here we explore how erosion assessments structured in the context of ecological sites (a land classification based on soils, landscape setting and ecological potential) and their vegetation states (plant assemblages that may change due to management) can inform systems for reducing accelerated soil erosion in rangelands. We evaluated aeolian horizontal sediment flux and fluvial sediment erosion rates for five ecological sites in southern New Mexico, USA, using monitoring data and rangeland-specific wind and water erosion models. Across the ecological sites, plots in shrub-encroached and shrub-dominated vegetation states were consistently susceptible to aeolian sediment flux and fluvial sediment erosion. Both processes were found to be highly variable for grassland and grass-succulent states across the ecological sites at the plot scale (0.25 Ha). We identify vegetation thresholds that define cover levels below which rapid (exponential) increases in aeolian sediment flux and fluvial sediment erosion occur across the ecological sites and vegetation states. Aeolian sediment flux and fluvial erosion in the study area can be effectively controlled when bare ground cover is 100 cm in length is less than ~35%. Land use and management activities that alter cover levels such that they cross thresholds, and/or drive vegetation state changes, may increase the susceptibility of areas to erosion. Land use impacts that are constrained within the range of natural variability should not result in accelerated soil erosion. Evaluating land condition against the erosion thresholds identified here will enable identification of areas susceptible to accelerated soil erosion and the development of

  1. Remote sensing as a tool for estimating soil erosion potential

    NASA Technical Reports Server (NTRS)

    Morris-Jones, D. R.; Morgan, K. M.; Kiefer, R. W.

    1979-01-01

    The Universal Soil Loss Equation is a frequently used methodology for estimating soil erosion potential. The Universal Soil Loss Equation requires a variety of types of geographic information (e.g. topographic slope, soil erodibility, land use, crop type, and soil conservation practice) in order to function. This information is traditionally gathered from topographic maps, soil surveys, field surveys, and interviews with farmers. Remote sensing data sources and interpretation techniques provide an alternative method for collecting information regarding land use, crop type, and soil conservation practice. Airphoto interpretation techniques and medium altitude, multi-date color and color infrared positive transparencies (70mm) were utilized in this study to determine their effectiveness for gathering the desired land use/land cover data. Successful results were obtained within the test site, a 6136 hectare watershed in Dane County, Wisconsin.

  2. A simplified close range photogrammetric technique for soil erosion assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface reconstruction using digital photogrammetry offers a great advantage for soil erosion research. The technology can be cumbersome for field application as it relies on the accurate measurement of control points often using a survey grade instruments. Also, even though digital photogrammetry h...

  3. A simplified close range photogrammetric technique for soil erosion assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface reconstruction using digital photogrammetry offers a great advantage for soil erosion research. The technology can be cumbersome for field application as it relies on the accurate measurement of control points often using a survey grade instrument. Also, even though digital photogrammetry ha...

  4. A simplified close range photogrammetry method for soil erosion assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the increased affordability of consumer grade cameras and the development of powerful image processing software, digital photogrammetry offers a competitive advantage as a tool for soil erosion estimation compared to other technologies. One bottleneck of digital photogrammetry is its dependency...

  5. Soil erosion and carbon budget in Mediterranean vineyards

    NASA Astrophysics Data System (ADS)

    Novara, Agata; Santoro, Antonino; Gristina, Luciano

    2016-04-01

    Vineyards of Mediterranean regions are characterized by low organic matter level and high sediment and nutrient erosion rates, which are the main causes of soil degradation and low sustainability of vine production. Alternative soil management - cover crops, green manure of prune residues, buffer strip- has widely applied as soil management practices to reduce soil degradation processes. However, the effectiveness of innovative soil management should be evaluated in relation to climatic and soil conditions. Many studies have been carried out in Sicilian vineyards in order to improve the sustainability with particular attention to: reduction of erosion, increase of soil organic matter, managing of nitrogen content and prune residue input. Besides the ecosystem service and its related economic aspects of the different soil management has been evaluated to analyze the wine growers and researchers demands. The aim of this work is to describe the state of art of scientific results on different soil management in Sicilian vineyards in the last 15 years, highlighting criticisms and lack of knowledge.

  6. Participatory assessment of soil erosion severity and performance of mitigation measured using stakeholders' workshops in Koga catchment, Ethiopia

    NASA Astrophysics Data System (ADS)

    Lakew, Walle; Baartman, Jantiene; Ritsema, Coen

    2016-04-01

    There has been little effort to systematically document the experiences and perceptions of farmers on soil erosion and soil and water conservation (SWC) even though a wealth of SWC knowledge and information exists, and there is a great demand to access it. Sustainable Land Management (SLM) has largely evolved through local traditional practices than being adopted on basis of scientific evidence. This research aimed to document the experiences of farmers on soil erosion and conservation, and to increase awareness and participation of the local community in SWC. Participatory stakeholders' workshops were undertaken at local level focused on experiences and perceptions of farmers. The workshops included group discussion and field monitoring of sheet erosion indicators, profiles of rills and gullies and impacts of SWC strategies. Systematic descriptions of the status of soil erosion, soil fertility and yield were used to assess the performances of SWC strategies. Results show that farmers were aware of the harmful effects of ongoing soil erosion and impacts of mitigation strategies on their farms. Sheet erosion was found to be the most damaging form of erosion while rill damage was critical on cereal cultivated farms on steep slopes. Farmers perceived that the desired impacts of SWC practices were attained in general: runoff and soil loss rates decreased, while soil fertility and production increased. The performance of SWC measures were found to be highly affected by the design quality and management strategies on the farm. Comparatively graded stone-faced soil bunds revealed maximum desired impacts and were liked by farmers whereas all level bunds caused water logging and traditional ditches begun incising and affected production of cereals. Bund maintenance practices were low and also distracted the stability of bunds. This calls for further improvement of design of SWC technologies and their maintenance. Further research should integrate the local knowledge for

  7. The global significance of omitting soil erosion from soil organic carbon cycling schemes

    NASA Astrophysics Data System (ADS)

    Chappell, Adrian; Baldock, Jeffrey; Sanderman, Jonathan

    2016-02-01

    Soil organic carbon (SOC) cycling schemes used in land surface models (LSMs) typically account only for the effects of net primary production and heterotrophic respiration. To demonstrate the significance of omitting soil redistribution in SOC accounting, sequestration and emissions, we modified the SOC cycling scheme RothC (ref. ) to include soil erosion. Net SOC fluxes with and without soil erosion for Australian long-term trial sites were established and estimates made across Australia and other global regions based on a validated relation with catchment-scale soil erosion. Assuming that soil erosion is omitted from previous estimates of net C flux, we found that SOC erosion is incorrectly attributed to respiration. On this basis, the Australian National Greenhouse Gas inventory overestimated the net C flux from cropland by up to 40% and the potential (100 year) C sink is overestimated by up to 17%. We estimated global terrestrial SOC erosion to be 0.3-1.0 Pg C yr-1 indicating an uncertainty of -18 to -27% globally and +35 to -82% regionally relative to the long-term (2000-2010) terrestrial C flux of several LSMs. Including soil erosion in LSMs should reduce uncertainty in SOC flux estimates with implications for CO2 emissions, mitigation and adaptation strategies and interpretations of trends and variability in global ecosystems.

  8. The Effect on Soil Erosion of Different Tillage Applications

    NASA Astrophysics Data System (ADS)

    Gür, Kazım

    2016-04-01

    The Effects on Soil Erosion of Different Tillage Applications Kazım Gür1, Kazim Çarman2 and Wim M.Cornelis3 1Bahri Daǧdaş International Agricultural Research Instıtute, 42020 Konya, Turkey 2Faculty of Agriculture, Department of Agricultural Machinery, University of Selçuk, 42031 Konya, Turkey 3Department of Soil Management, Faculty of Bioscience Engineering, Ghent University, 653 Coupure Links, 9000 Gent, Belgium Traditional soil cultivation systems, with excessive and inappropriate soil tillage, will generally lead to soil degradation and loss of soil by wind erosion. Continuous reduced tillage and no-till maintaining soil cover with plant residues called Conservation Agriculture that is considered as effective in reducing erosion. There exist a wide variety of practices using different tools that comply with reduced tillage principles. However, few studies have compared the effect of several of such tools in reducing wind erosion and related soil and surface properties. We therefore measured sediment transport rates over bare soil surfaces (but with under stubbles of wheat, Triticum aestivum L.) subjected to three tillage practices using two pulling type machines and one type of power takeoff movable machines and generated with a portable field wind tunnel. At 10 ms-1, sediment transport rates varied from 107 to 573 gm-1h-1, and from 176 to 768 gm-1h-1 at 13 ms-1. The lowest transport rates were observed for N(no-tillage) and the highest for Rr(L-type rototiller). After tillage, surface roughness, mean weighted diameter, wind erodible fraction, mechanical stability and soil water content were measured as well and varied from 5.0 to 15.9%, 6.9 to 13.8 mm, 14.3 to 29.7%, 79.5 to 93.4% and 8.6 to 15.1%, respectively, with again N is being the most successful practice. In terms of conservation soil tillage technique, it can be said that the applications compared with each other; direct sowing machine is more appropriate and cause to the less erosion.

  9. Cover crops effectiveness for soil erosion control in Sicilian vineyard

    NASA Astrophysics Data System (ADS)

    Gristina, L.; Novara, A.; Saladino, S.; Santoro, A.

    2009-04-01

    In vineyards, which are very common in Mediterranean area, cover crops are becoming increasingly used to reduce soil erosion. Cover crops reduce runoff by increasing infiltration and increasing roughness and then reducing the ovelandflow velocity. The aim of the present study was to quantify soil and water losses under different soil managements systems on vineyards. The study site was a Sauvignon blanc winegrape vineyard located in Southwestern Sicily. Vineyards were managed both traditionally (conventional tillage) and alternative management using cover crops: 1) Vicia faba ; 2) Vicia faba and Vicia sativa; 3) Trifolium subterraneum, Lolium perenne, Festuca rubra; 4)Trifolium subterraneum, Festuca rubra and Festuca ovina, 5) Triticum durum, 6) Triticum durum and Vicia sativa. To monitor water and sediment yield, a Gerlach trough was installed at each treatment on the vineyard inter-row, with the row vineyard used as a border (topographical border). Runoff was measured after each rainfall event (raingauge 0.2 mm accuracy) from November 2005 to April 2007. And sediments were measured after desiccation. The results show that runoff and erosion were reduced considerably under the treatments with Trifolium subterraneum, Lolium perenne, Festuca rubra and Trifolium subterraneum, Festuca rubra and Festuca ovina (treatments 3 and 4). The soil losses were reduced by 73% under treatment 4 compared to the tillage plot. Conventional tillage and alternative management using Vicia faba cover crop (treatment 1) result the most ineffective treatment to soil erosion. These results show that the use of a cover crop can be a simple soil and water conservation practice in Sicilian vineyards. Key words: soil erosion, cover crops, vineyard, Mediterranean area.

  10. Assessing the impact of soil management on soil erosion in vineyards in La Rioja (Spain): La Sierra de Los Agudos

    NASA Astrophysics Data System (ADS)

    Galilea Salvador, Ianire; Lana-Renault, Noemí; Ruiz Flaño, Purificación; Ángel Llorente Adán, Jose; Bellido, Nuria Pascual

    2015-04-01

    La Rioja is a predominantly agricultural region located in the northwestern corner of the Ebro Basin in Spain. In this region, vineyards are a crop of historical and economical importance and large extension that traditionally has been relegated to marginal lands, mainly glacis, high fluvial terraces and slopes linking different levels of terraces and glacis. It is well known that vineyards are among the land uses affected by largest soil erosion losses. Surprisingly, many farmers still apply non-conservative practices that contribute to an increase of soil erosion. In spite of the environmental and economic consequences, very little research on this topic has been undertaken in the region. In this study, we assessed the impact of vineyards and soil management practices on soil erosion in La Sierra de Los Agudos, a heavily eroded area located on quaternary silt loam and clay glacis, where vineyards represent 30% of the agricultural land. For this purpose we used an adapted version of the RUSLE model: R was estimated using data from two nearby weather stations following the methodology of Arnoldus and Fournier for a lapse time of five years; K was assessed from 28 soil samples analyzed by the National Institute of Soil Erosion, and the edaphic map of La Rioja which includes 32 taxa; C was calculated from catastral data, the Information System of Land Occupation, and by a detailed study of each subfactor; LS was obtained from a 10 meters/pixel scale DTM from which the slope length and the percentage of inclination of the slopes was calculated; and P was established by observing different tillage practices in each of the plots. Low erosion values (<0,001-2 Mg ha-¹year-¹) were estimated for the 43 % of the area, while the 37% was affected by moderate (2-12 Mg ha-¹year-¹) and high erosion values (>12 Mg ha-¹year-¹) which exceed the soil loss tolerance (T value) established by Renard (1996). In this study we showed that the current support practices accelerate soil

  11. The effects of mulching on soil erosion by water. A review based on published data

    NASA Astrophysics Data System (ADS)

    Prosdocimi, Massimo; Jordán, Antonio; Tarolli, Paolo; Cerdà, Artemi

    2016-04-01

    Among the soil conservation practices that have been recently implemented, mulching has been successfully applied in different contexts (Jordán et al., 2011), such as agricultural lands (García-Orenes et al. 2009; Prosdocimi et al., 2016), fire-affected areas (Prats et al., 2014; Robichaud et al., 2013) and anthropic sites (Hayes et al., 2005), to reduce water and soil losses rates. In these contexts, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas of the world (Cerdà et al., 2009; Cerdan et al., 2010; Sadeghi et al., 2015). Although soil erosion by water consists of physical processes that vary significantly in severity and frequency according to when and where they occur, they are also strongly influenced by anthropic factors such as unsustainable farming practices and land-use changes on large scales (Cerdà, 1994; Montgomery, 2007). Although the beneficial effects of mulching are known, their quantification needs further research, especially in those areas where soil erosion by water represents a severe threat. In literature, there are still some uncertainties about how to maximize the effectiveness of mulching in the reduction of soil and water loss rates. First, the type of choice of the vegetative residues is fundamental and drives the application rate, cost, and consequently, its effectiveness. Second, it is important to assess application rates suitable for site-specific soil and environment conditions. The percentage of area covered by mulch is another important aspect to take into account, because it has proven to influence the reduction of soil loss. And third, the role played by mulching at catchment scale, where it plays a key role as barrier for breaking sediment and runoff connectivity. Given the seriousness of soil erosion by water and the uncertainties that still concern the correct use of mulching, this work aims to evaluate the effects of mulching on soil erosion rates and water losses in agricultural

  12. Topographic changes detection through Structure-from-Motion in agricultural lands affected by erosion processes

    NASA Astrophysics Data System (ADS)

    Prosdocimi, Massimo; Pradetto Sordo, Nicoletta; Burguet, Maria; Di Prima, Simone; Terol Esparza, Enric; Tarolli, Paolo; Cerdà, Artemi

    2016-04-01

    Throughout the world, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas (Cerdà et al., 2009; Cerdan et al., 2010; García-Ruiz, 2010). Although soil erosion by water consists of physical processes that vary significantly in severity and frequency according to when and where they occur, they are also strongly influenced by anthropic factors such as land-use changes on large scales and unsustainable farming practices (Boardman et al., 1990; Cerdà 1994; Montgomery, 2007). Tillage operations, combined with weather conditions, are recognized to primarily influence soil erosion rates. If, on one hand, tillage operations cause uniform changes based on the tool used, on the other, weather conditions, such as rainfalls, produce more random changes, less easily traceable (Snapir et al., 2014). Within this context, remote-sensing technologies can facilitate the detection and quantification of these topographic changes. In particular, a real opportunity and challenge is offered by the low-cost and flexible photogrammetric technique, called 'Structure-from-Motion' (SfM), combined with the use of smartphones (Micheletti et al., 2014; Prosdocimi et al., 2015). This represents a significant advance compared with more expensive technologies and applications (e.g. Terrestrial Laser Scanner - TLS) (Tarolli, 2014). This work wants to test the Structure from Motion to obtain high-resolution topography for the detection of topographic changes in agricultural lands affected by erosion processes. Two case studies were selected: i) a tilled plot characterized by bare soil and affected by rill erosion located in the hilly countryside of Marche region (central Italy), and ii) a Mediterranean vineyard located within the province of Valencia (south eastern Spain) where rainfall simulation experiments were carried out. Extensive photosets were obtained by using one standalone reflex digital camera and one smartphone built-in digital camera. Digital

  13. 7 CFR 610.13 - Equations for predicting soil loss due to wind erosion.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Equations for predicting soil loss due to wind erosion... RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE CONSERVATION OPERATIONS TECHNICAL ASSISTANCE Soil Erosion Prediction Equations § 610.13 Equations for predicting soil loss due to wind erosion. (a)...

  14. 7 CFR 610.13 - Equations for predicting soil loss due to wind erosion.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Equations for predicting soil loss due to wind erosion... RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE CONSERVATION OPERATIONS TECHNICAL ASSISTANCE Soil Erosion Prediction Equations § 610.13 Equations for predicting soil loss due to wind erosion. (a)...

  15. 7 CFR 610.13 - Equations for predicting soil loss due to wind erosion.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Equations for predicting soil loss due to wind erosion... RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE CONSERVATION OPERATIONS TECHNICAL ASSISTANCE Soil Erosion Prediction Equations § 610.13 Equations for predicting soil loss due to wind erosion. (a)...

  16. Erosion Modelling In A Mediterranean Subcatchment Under Climate Change Scenarios Using Pan-European Soil Erosion Risk Assessment (PESERA)

    NASA Astrophysics Data System (ADS)

    Cilek, A.; Berberoglu, S.; Kirkby, M.; Irvine, B.; Donmez, C.; Erdogan, M. A.

    2015-04-01

    The Mediterranean region is particularly prone to erosion. This is because it is subject to long dry periods followed by heavy bursts of erosive rainfall, falling on steep slopes with fragile soils, resulting in considerable amounts of erosion. In parts of the Mediterranean region, erosion has reached a stage of irreversibility and in some places erosion has practically ceased because there is no more soil left. With a very slow rate of soil formation, any soil loss of more than 1 t ha-1 yr-1 can be considered as irreversible within a time span of 50-100 years. The objectives of this study were i) to estimate the temporal and spatial distribution of soil erosion under climate change scenarios in study area ii) to assess the hydrological runoff processes. In this study, climate data, land use, topographic and physiographic properties were assembled for Egribuk Subcatchment at Seyhan River Basin in Turkey and used in a process-based Geographical Information System (GIS) to determine the hydrological sediment potential and quantify reservoir sedimentation. The estimated amount of sediment transported downstream is potentially large based on hydrological runoff processes using the Pan-European Soil Erosion Risk Assessment (PESERA) model. The detailed model inputs included 128 variables derived mainly from, soil, climate, land use/cover, topography data sets. The outcomes of this research were spatial and temporal distribution of erosion amount in t ha-1 yr-1 or month-1.

  17. The Future of Soil Erosion Modelling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The movement of sediment and associated pollutants over the landscape and into water bodies is of increasing concern with respect to pollution control, prevention of muddy floods and environmental protection. In addition, the loss of soil on site has implications for declining agricultural productiv...

  18. Weather types, precipitation and soil erosion in the Iberian Peninsula

    NASA Astrophysics Data System (ADS)

    Nadal Romero, Estela; Cortesi, Nicola; Lucia, Ana; Pacheco, Edinson; Taguas, Encarnación; Francisco Martínez-Murillo, Juan; Romero Díaz, Asunción; Gómez, José Alfonso; Úbeda, Xavi; Damián Ruiz-Sinoga, José; Lasanta, Teodoro; González-Hidalgo, Carlos

    2014-05-01

    For a long time, precipitation has been recognized as one of the main factors driving soil erosion and sediment yield. In climatology, one of the most common approaches in analyzing precipitation is the circulation of weather types (WTs), which categorize the continuum of atmospheric circulation into a small number of classes or types. In the Iberian Peninsula (IP), previous researches have demonstrated the usefulness of the WT approach in determining the behavior of rainfall, and its spatial and temporal distribution. These studies have shown that specific weather types are the main driven factors of precipitation distribution accordingly different areas, and shown that precipitations depends on more WTs to the west than to the east of the IP. In this study, we present an analysis of weather types and sediment yield data from different study areas in the Iberian Peninsula. To do that we have collected and joint different research groups spread along the national Spanish land, and combine different databases with the WT classification calculated using the NMC/NCAR 40-Year Reanalysis Project. We discuss two main hypotheses: (i) there exist some links between weather types and soil erosion in the Iberian Peninsula, and then (ii) spatial patterns of sediment yield and erosion would be emerged in the Iberian Peninsula accordingly the spatial distribution of the relationship between WTs and sedimentary processes. This pioneer research, with different areas across the Iberian Peninsula will be a valuable tool in understanding the relationships between weather types, precipitation and soil erosion dynamics.

  19. Weathering, Soil Production, and Erosion Across Climatic and Tectonic Gradients

    NASA Astrophysics Data System (ADS)

    Norton, K. P.; Larsen, I. J.

    2014-12-01

    Weathering is one of the fundamental processes that sustain life on our planet. Physical weathering breaks down rock for soil production and chemical weathering is thought to operate as the ultimate long-term negative feedback on atmospheric CO2 concentrations. There remains, however, uncertainty as to the relationship between chemical and physical weathering at very fast rates. If chemical weathering becomes kinetically limited at rapid erosion rates, as has been shown in a number of locations around the globe, then the fastest erosion rates will be associated with reduced chemical weathering. This has led to a debate as to whether tectonically active mountain ranges or rolling plains are the main source of CO2 drawdown through silicate weathering. At the heart of this debate is the dearth of chemical weathering data at fast erosion rates. New cosmogenic nuclide-derived denudation rates from the West Coast of the New Zealand Southern Alps are among the fastest in the world and are linearly correlated with chemical weathering rates. The associated soil production rates reach an order of magnitude faster than previous estimates and far exceed the suggested maximum soil production rate. This suggests that very fast weathering and soil production is possible in such active landscapes and extreme climates. We investigate the controls on these rapid rates with a climate-driven soil production model. At the most basic level, soil production requires chemical weathering of primary minerals to secondary minerals. We apply soil production models with both exponential and hump-shaped dependencies on soil thickness. Mean annual temperature and precipitation are incorporated in the form of a modified Arrhenius equation that controls the maximum soil production rate. When applied to the Southern Alps, the model predicts very rapid soil production that matches the magnitude of the cosmogenic nuclide-derived rates. High annual precipitation in the Southern Alps supports rapid

  20. Topographic changes detection through Structure-from-Motion in agricultural lands affected by erosion processes

    NASA Astrophysics Data System (ADS)

    Prosdocimi, Massimo; Pradetto Sordo, Nicoletta; Burguet, Maria; Di Prima, Simone; Terol Esparza, Enric; Tarolli, Paolo; Cerdà, Artemi

    2016-04-01

    Throughout the world, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas (Cerdà et al., 2009; Cerdan et al., 2010; García-Ruiz, 2010). Although soil erosion by water consists of physical processes that vary significantly in severity and frequency according to when and where they occur, they are also strongly influenced by anthropic factors such as land-use changes on large scales and unsustainable farming practices (Boardman et al., 1990; Cerdà 1994; Montgomery, 2007). Tillage operations, combined with weather conditions, are recognized to primarily influence soil erosion rates. If, on one hand, tillage operations cause uniform changes based on the tool used, on the other, weather conditions, such as rainfalls, produce more random changes, less easily traceable (Snapir et al., 2014). Within this context, remote-sensing technologies can facilitate the detection and quantification of these topographic changes. In particular, a real opportunity and challenge is offered by the low-cost and flexible photogrammetric technique, called 'Structure-from-Motion' (SfM), combined with the use of smartphones (Micheletti et al., 2014; Prosdocimi et al., 2015). This represents a significant advance compared with more expensive technologies and applications (e.g. Terrestrial Laser Scanner - TLS) (Tarolli, 2014). This work wants to test the Structure from Motion to obtain high-resolution topography for the detection of topographic changes in agricultural lands affected by erosion processes. Two case studies were selected: i) a tilled plot characterized by bare soil and affected by rill erosion located in the hilly countryside of Marche region (central Italy), and ii) a Mediterranean vineyard located within the province of Valencia (south eastern Spain) where rainfall simulation experiments were carried out. Extensive photosets were obtained by using one standalone reflex digital camera and one smartphone built-in digital camera. Digital

  1. Terraced agriculture protects soil from erosion: Case studies in Madagascar

    NASA Astrophysics Data System (ADS)

    Rabesiranana, Naivo; Rasolonirina, Martin; Fanantenansoa Solonjara, Asivelo; Nomenjanahary Ravoson, Heritiana; Mabit, Lionel

    2016-04-01

    - Soil degradation is a major concern in Madagascar but quantitative information is not widely available. Due to its impact on the sustainability of agricultural production, there is a clear need to acquire data on the extent and magnitude of soil erosion/sedimentation under various agricultural practices in order to promote effective conservation strategies. Caesium-137 and 210Pbex fallout radionuclides (FRNs) possess particular characteristics that make them effective soil tracers for erosion studies. After fallout, 137Cs and 210Pbex are rapidly adsorbed onto fine soil particles. But to date, combined use of these FRNs has never been used to document soil erosion in Madagascar. The study area is located 40 km east of Antananarivo, in Madagascar highlands. Two adjacent cultivated fields have been selected (i.e. a sloped field and a terraced field) as well as an undisturbed reference site in the vicinity of these agricultural fields. Soil samples were collected along downslope transects using motorized corer. The 137Cs and 210Pb gamma analysis were performed at the Institut National des Sciences et Techniques Nucléaires (INSTN-Madagascar) using a high resolution and low background N-type HPGe detector. Results showed that at the terraced field, 137Cs and 210Pbex inventories reached 145 Bq/m2 to 280 Bq/m2 and 2141 Bq/m2 to 4253 Bq/m2, respectively. At the sloped field, the 137Cs and 210Pbex inventories values ranged from 110 Bq/m2 to 280 Bq/m2 and from 2026 Bq/m2 to 4110 Bq/m2, respectively. The net soil erosion determined for the sloped field were 9.6 t/ha/y and 7.2 t/ha/y for 137Cs and 210Pbex methods, respectively. In contrast, at the terraced field, the net soil erosion rates reached only 3.4 t/ha/y and 3.8 t/ha/y, respectively. The preliminary results of this research highlighted that terraced agricultural practice provides an efficient solution to protect soil resources of the Malagasy highlands.

  2. Impact of land consolidation and field borders on soil erosion and storage within agricultural landscapes

    NASA Astrophysics Data System (ADS)

    Chartin, Caroline; Salvador-Blanes, Sébastien; Olivier, Evrard; Van Oost, Kristof; Hinschberger, Florent; Macaire, Jean-Jacques

    2014-05-01

    Soil erosion plays an important role in sediment and carbon storage within, and exports from, catchments. In cultivated landscapes, field borders can improve the temporary storage of eroded soil particles and associated carbon, by impeding lateral soil fluxes. These local soil accumulations can lead to the development of linear landforms (such as headlands and lynchets) which will keep evolving after field border removal. A recent study performed in a representative cultivated hillslope of the SW Parisian Basin showed that 39% of the area corresponds to landforms resulting from soil accumulation induced by former and present field borders. This study demonstrated that field borders influence greatly the landscape morphology, but also the spatial distribution of soil thickness, and locally the A-horizon thickness, which are essential parameters for the prediction of SOC stocks. This study aims at characterizing and quantifying the effect of field borders and their removal on medium term topsoil erosion and deposition rates in a cultivated hillslope of the SW Parisian Basin, consolidated in 1967. Here, we used the Cs-137 technique to assess recent patterns of soil redistribution. We measured the Cs-137 inventories of 68 soil cores sampled along transects covering the area and, more specifically, linear landforms identified along present and past field borders (i.e., lynchet and undulation landforms, respectively). Then, we used a spatially-distributed Cs-137 conversion model that simulates and discriminates soil redistribution induced by water and tillage erosion processes over the last fifty years. Finally, observations and model outputs were confronted. Our results show that tillage erosion dominate the soil redistribution in the study area for the 1954-2009 period and generated about 95% (i.e., 4.50 Mg.ha-1.yr-1) of the total gross erosion. Soil redistribution was largely affected by the presence of current and former field borders, where hotspots areas of

  3. Weathering and soil erosion at watershed scale in St. John, US Virgin Islands.

    NASA Astrophysics Data System (ADS)

    Gudiño, Napoleón; Kretzschmar, Thomas; Gray, Sarah

    2015-04-01

    Human activities may increase soil erosion and the delivery of land-based sediment into coastal waters from steep sub-tropical islands. These changes may also affect water-rock interaction, which alters the geochemistry of storm-water and the clay mineralogy of eroded sediments. The purpose of this analysis is to compare storm-water, sediment geochemistry and modeled erosion rates between developed and undeveloped watersheds on Saint John, United States Virgin Islands (USVI). The saturation index was calculated by "The Geochemist's Workbench", supported by X-Ray diffraction on clay minerals. The Revised and Modified Universal Soil Loss Equations were used to estimate both annual mean (2010) and storm-event (Hurricane Otto) based erosion rates. Relative concentration of illite was higher in Coral Bay. Calculated RUSLE/MUSLE-based erosion rates were higher for the developed compared to the undeveloped watersheds. Results of this investigation suggest that rural/urban development of watersheds may increase the weathering, soil erosion and coastal sedimentation causing a negative effect on the marine ecosystem in St. John USVI.

  4. Effect of selected soil conditioners on soil properties, erosion, runoff, and rye growth in nonfertile acid soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Construction operations result in highly disturbed soil, vulnerable to erosion and excess runoff and sediment loads. Limited information exists about effects of erosion mitigation practices on soil and runoff properties in low fertility acidic sites. The current study evaluates the use of polyacry...

  5. Influence of soil management on water erosion and hydrological responses in semiarid agrosystems

    NASA Astrophysics Data System (ADS)

    De Alba, Saturnino; Alcazar, María; Ivón Cermeño, F.

    2014-05-01

    In Europe, in the Mediterranean area, water erosion is very severe, moderately to seriously affecting 50% to 70% of the agricultural land. However, it is remarkable the lack of field data of water erosion rates for agricultural areas of semiarid Mediterranean climate. Moreover, this lack of field data is even more severe regarding the hydrological and erosive responses of soils managed with organic farming compared to those with conventional managements or others under conservation agriculture. This paper describes an experimental field station (La Higueruela Station) for the continuous monitoring of water erosion that was set up in 1992 in Central Spain (Toledo, Castilla-La Mancha). In the study area, the annual precipitation is around 450 mm with a very irregular inter-annual and seasonal distribution, which includes a strong drought in summer. The geology is characterised by non-consolidated Miocene materials, mostly arcosics. The area presents a low relief and gentle slopes, generally less than 15%. At the experimental field, the soil is a Typic Haploxeralf (USDA, 1990). The land-uses are rainfed crops mainly herbaceous crops, vineyard and olive trees. The hydrological response and soil losses by water erosion under natural rainfall conditions are monitored in a total of 28 experimental plots of the USLE type. The plots have a total area of 33.7 m2, (22.5 m long downslope and 3 m wide) and presented a slope gradient of 9%. Detailed descriptions of the experimental field facilities and the automatic station for monitoring runoff and sediment productions, as well as of the meteorological station, are presented. The land uses and treatments applied on the experimental plots are for different soil management systems for cereals crops (barley): 1) Organic farming, 2) Minimum tillage of moderate tillage intensity, 3) No-tillage, and 4) Conventional tillage; five alternatives of fallow: 1) Traditional fallow (white fallow) with conventional tillage, 2) Traditional

  6. Assessing the contribution of nonhydraulic forces to the destruction of bonds between soil particles during water erosion

    NASA Astrophysics Data System (ADS)

    Larionov, G. A.; Bushueva, O. G.; Dobrovol'skaya, N. G.; Kiryukhina, Z. P.; Litvin, L. F.; Krasnov, S. F.

    2016-05-01

    It has been experimentally shown with monoaggregate model samples of chernozemic soil as an example that the weakening of cohesion between soil particles is due to the molecular interaction of soil particles with water as a dipole substance rather than to the hydraulic forces of the flow. Therefore, soil erosion should be considered as a two-stage process. First, the bonds between particles are weakened due to the interaction of soil particles with water; then, the particles that lost bonds with neighboring ones are entrapped by the flow. Thus, the erosion rate of a consolidated soil is determined by the destruction of bonds between particles during their interaction with water, rather than the flow velocity, although this factor also affects the erosion rate.

  7. Using connectivity to assess soil erosion in the landscape; applications of a new paradigm in soil erosion modelling

    NASA Astrophysics Data System (ADS)

    Borselli, Lorenzo; Vigiak, Olga; Ortiz Rodriguez, Azalea Judith

    2013-04-01

    Hydrologic and sedimentological connectivity concepts recently appeared as novel paradigms (Bracken and Croke , 2007) and tools to assess soil erosion at various scales. The landscape flow connectivity index IC (Borselli et al. 2007, 2008) is based on the ratio of hydrological distance to streams with the potential upstream runoff occurrence, hence allows mapping surface runoff connectivity and erosion across the landscape. After its first introduction, several studies applied the IC algorithm in very different geographic regions and territorial scale: 150 km2 watershed in Tuscany (Italy; Borselli et al. 2007, 2008); 20 small catchments (5 to 350 ha) in Murcia (Spain; Sougnez et al. 2011); 400 km2 watershed in Basilicata (South Italy; Borselli et al. 2011); 3300 km2 watershed in Victoria (Australia; Vigiak et al. 2012); 6 and 8 km2watersheds in the Italian Alps (Cavalli et al., in press); 74 ha catchment in Spanish Pre-Pyrenees (López-Vicente et al. 2013). Meanwhile, the IC index has been adapted for application to different erosion processes, i.e. hillslope erosion (Vigiak et al. 2012; López-Vicente et al. 2013), sediment remobilization by shallow landslides (Borselli et al. 2011), and debris flow (Cavalli et al. in press). Validation of IC index applications in spatially distributed erosion models has been conducted with field observations at hillslope scale, calibration against sediment yield estimates at several monitoring stations. These scientific results highlight the promising potential application of IC concept for erosion modelling. In this session, the IC model with all its proposed variants will be described. Future work perspectives, including potential developments of IC approach as an alternative method to classical soil erosion modelling, will be discussed. Acknowledgement: This study has been funded by CONACYT (Mexico); Proyecto CB-2012-01/184060

  8. Examining soil erosion and nutrient accumulation in forested and agriculture lands of the low mountainous area of Northern Vietnam

    NASA Astrophysics Data System (ADS)

    Pham, A. T.; Gomi, T.; Takahisa, F.; Phung, K. V.

    2011-12-01

    We examined soil erosion and nutrient accumulations in the Xuanmai area located in the low mountainous region of Northern Vietnam, based on field investigations and remote sensing approaches. The study area had been degraded by land-use change from forest to agriculture in the last 20 years. In contrast, around the study area, the Vietnam government promoted reforestation projects. Such changes in land-use conditions, which may or may not be associated with vegetation ground cover conditions, potentially alter soil erosion and nutrient accumulation. We selected 10 dominant land-use types including forested land (e.g., Pinus massoniana and Acacia mangium plantation) agriculture land (e.g., Cassava), and bare land. We established three 1 x 1 m plots in each land-use type in September 2010. Vegetation biomass, litter cover, soil erosion (height of soil pedestal), and soil physical (soil bulk density and particle size distribution) and chemical properties (Total soil carbon, nitrate, and phosphorus) were measured. Height of soil pedestal can be a record of soil erosion by rain splash during rainy periods from April to August (prior to our field study). We also conducted remote sensing analysis using Landsat TM images obtained in 1993, 2000, and 2007 for identifying temporal patterns of land-use types. We found that the intensity of soil erosion depended primary on current vegetation ground cover condition with no regard of land-use. Hence, nutrient accumulation varied among vegetation ground cover and soil erosion. Remote sensing analysis suggested that shrub and bare lands had been altered from forested land more recently. Our finding suggested that variability of soil nutrient conditions can be associated with long-term soil erosion and production processes. Findings of our study are that: (1) current vegetation and litter ground cover affected the amount of surface soil erosion, and (2) legacy of land-use can be more critical for soil nutrient accumulation. Both

  9. Modeling carbon dynamics in vegetation and soil under the impact of soil erosion and deposition

    USGS Publications Warehouse

    Liu, S.; Bliss, N.; Sundquist, E.; Huntington, T.G.

    2003-01-01

    Soil erosion and deposition may play important roles in balancing the global atmospheric carbon budget through their impacts on the net exchange of carbon between terrestrial ecosystem and the atmosphere. Few models and studies have been designed to assess these impacts. In this study, we developed a general ecosystem model, Erosion-Deposition-Carbon-Model (EDCM), to dynamically simulate the influences of rainfall-induced soil erosion and deposition on soil organic carbon (SOC) dynamics in soil profiles. EDCM was applied to several landscape positions in the Nelson Farm watershed in Mississippi, including ridge top (without erosion or deposition), eroding hillslopes, and depositional sites that had been converted from native forests to croplands in 1870. Erosion reduced the SOC storage at the eroding sites and deposition increased the SOC storage at the depositional areas compared with the site without erosion or deposition. Results indicated that soils were consistently carbon sources to the atmosphere at all landscape positions from 1870 to 1950, with lowest source strength at the eroding sites (13 to 24 gC m-2 yr-1), intermediate at the ridge top (34 gC m-2 yr-1), and highest at the depositional sites (42 to 49 gC m-2 yr-1). During this period, erosion reduced carbon emissions via dynamically replacing surface soil with subsurface soil that had lower SOC contents (quantity change) and higher passive SOC fractions (quality change). Soils at all landscape positions became carbon sinks from 1950 to 1997 due to changes in management practices (e.g., intensification of fertilization and crop genetic improvement). The sink strengths were highest at the eroding sites (42 to 44 gC m-2 yr-1 , intermediate at the ridge top (35 gC m-2 yr-1), and lowest at the depositional sites (26 to 29 gC m-2 yr-1). During this period, erosion enhanced carbon uptake at the eroding sites by continuously taking away a fraction of SOC that can be replenished with enhanced plant residue

  10. Control of Eolian soil erosion from waste site surface barriers

    SciTech Connect

    Ligotke, M.W.

    1994-11-01

    Physical models were tested in a wind tunnel to determine optimum surface-ravel admixtures for protecting silt-loam soil from erosion by, wind and saltating, sand stresses. The tests were performed to support the development of a natural-material surface barrier for and waste sites. Plans call for a 2-m deep silt-loam soil reservoir to retain infiltrating water from rainfall and snowmelt. The objective of the study was to develop a gravel admixture that would produce an erosion-resistant surface layer during, periods of extended dry climatic stress. Thus, tests were performed using simulated surfaces representing dry, unvegetated conditions present just after construction, after a wildfire, or during an extended drought. Surfaces were prepared using silt-loam soil mixed with various grades of sand and Travel. Wind-induced surface shear stresses were controlled over the test surfaces, as were saltating, sand mass flow rates and intensities. Tests were performed at wind speeds that approximated and exceeded local 100-year peak gust intensities. Surface armors produced by pea gravel admixtures were shown to provide the best protection from wind and saltating sand stresses. Compared with unprotected silt-loam surfaces, armored surfaces reduced erosion rates by more than 96%. Based in part on wind tunnel results, a pea gravel admixture of 15% will be added to the top 1 in of soil in a prototype barrier under construction in 1994. Field tests are planned at the prototype site to provide data for comparison with wind tunnel results.

  11. Irrigation: Erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation is essential for global food production. However, irrigation erosion can limit the ability of irrigation systems to reliably produce food and fiber in the future. The factors affecting soil erosion from irrigation are the same as rainfall—water detaches and transports sediment. However, t...

  12. Soil erosion modelling nowadays: insights of a young scientist

    NASA Astrophysics Data System (ADS)

    López-Vicente, Manuel; Kirkby, Mike

    2013-04-01

    Soil erosion models allow mapping and quantifying rates of runoff depth and soil redistribution in a wide variety of environments for different land uses and climatic scenarios. Runoff generation, soil detachment, sediment delivery and river dynamic are non-linear processes that depend on many factors, and thus the development of accurate and broad models has being always a difficult task. Taking in mind this complexity, predicting models have evolved from the first empirical equations (1930's) to the current ambitious and GIS-based models. The first attempts were developed for small areas like the studies of Mockus (1949) and Andrews (1954) that constituted the basis of the runoff Curve Number (SCS-CN). The research of Wischmeier and Smith (1958 and 1978) in plots about the relationship between rainfall energy, soil erodibility and soil loss as well as the development of the Universal Soil Loss Equation became the RUSLE model (Renard et al., 1991) that has been one of the most applied models of rill and interrill erosion. A recent version of RUSLE is the WATEM/SEDEM (Van Rompaey et al., 2001) model that predicts spatially distributed rates of soil loss and deposition at catchment scale and also estimates tillage erosion. Other models simulated not only processes of surface runoff and soil erosion but processes of nutrients, pollutants and sediment delivery, such as CREAMS (Kinsel, 1980) and AGNPS (Young et al., 1987). The assistance of GIS techniques in the 1990's was a milestone that let scientists create advanced models such as the dynamic LISEM (De Roo et al., 1995) and the hydrological STREAM (Cerdan et al., 2002) models. In some cases the current models can be downloaded as executable files: the empirical RUSLE2 (Foster et al., 2000), the process-based WEPP (Adams et al., 2012) and DR2 (López-Vicente and Navas, 2012), the complex river basin SWAT (Arnold et al., 1998) and TETIS (Francés et al., 2007) and the reduced-complexity SedNet (Prosser et al., 2001

  13. Runoff generation and soil erosion processes after clear cutting

    NASA Astrophysics Data System (ADS)

    Mohr, Christian H.; Coppus, Ruben; Iroumé, AndréS.; Huber, Anton; Bronstert, Axel

    2013-06-01

    Timber harvesting by clear cutting is known to impose environmental impacts, including severe disturbance of the soil hydraulic properties which intensify the frequency and magnitude of surface runoff and soil erosion. However, it remains unanswered if harvest areas act as sources or sinks for runoff and soil erosion and whether such behavior operates in a steady state or evolves through time. For this purpose, 92 small-scale rainfall simulations of different intensities were carried out under pine plantation conditions and on two clear-cut harvest areas of different age. Nonparametrical Random Forest statistical models were set up to quantify the impact of environmental variables on the hydrological and erosion response. Regardless of the applied rainfall intensity, runoff always initiated first and yielded most under plantation cover. Counter to expectations, infiltration rates increased after logging activities. Once a threshold rainfall intensity of 20 mm/h was exceeded, the younger harvest area started to act as a source for both runoff and erosion after connectivity was established, whereas it remained a sink under lower applied rainfall intensities. The results suggest that the impact of microtopography on surface runoff connectivity and water-repellent properties of the topsoil act as first-order controls for the hydrological and erosion processes in such environments. Fast rainfall-runoff response, sediment-discharge-hystereses, and enhanced postlogging groundwater recharge at catchment scale support our interpretation. At the end, we show the need to account for nonstationary hydrological and erosional behavior of harvest areas, a fact previously unappreciated in predictive models.

  14. Soil organic carbon redistribution by water erosion--the role of CO2 emissions for the carbon budget.

    PubMed

    Wang, Xiang; Cammeraat, Erik L H; Romeijn, Paul; Kalbitz, Karsten

    2014-01-01

    A better process understanding of how water erosion influences the redistribution of soil organic carbon (SOC) is sorely needed to unravel the role of soil erosion for the carbon (C) budget from local to global scales. The main objective of this study was to determine SOC redistribution and the complete C budget of a loess soil affected by water erosion. We measured fluxes of SOC, dissolved organic C (DOC) and CO2 in a pseudo-replicated rainfall-simulation experiment. We characterized different C fractions in soils and redistributed sediments using density fractionation and determined C enrichment ratios (CER) in the transported sediments. Erosion, transport and subsequent deposition resulted in significantly higher CER of the sediments exported ranging between 1.3 and 4.0. In the exported sediments, C contents (mg per g soil) of particulate organic C (POC, C not bound to soil minerals) and mineral-associated organic C (MOC) were both significantly higher than those of non-eroded soils indicating that water erosion resulted in losses of C-enriched material both in forms of POC and MOC. The averaged SOC fluxes as particles (4.7 g C m(-2) yr(-1)) were 18 times larger than DOC fluxes. Cumulative emission of soil CO2 slightly decreased at the erosion zone while increased by 56% and 27% at the transport and depositional zone, respectively, in comparison to non-eroded soil. Overall, CO2 emission is the predominant form of C loss contributing to about 90.5% of total erosion-induced C losses in our 4-month experiment, which were equal to 18 g C m(-2). Nevertheless, only 1.5% of the total redistributed C was mineralized to CO2 indicating a large stabilization after deposition. Our study also underlines the importance of C losses by particles and as DOC for understanding the effects of water erosion on the C balance at the interface of terrestrial and aquatic ecosystems. PMID:24802350

  15. Soil Organic Carbon Redistribution by Water Erosion – The Role of CO2 Emissions for the Carbon Budget

    PubMed Central

    Wang, Xiang; Cammeraat, Erik L. H.; Romeijn, Paul; Kalbitz, Karsten

    2014-01-01

    A better process understanding of how water erosion influences the redistribution of soil organic carbon (SOC) is sorely needed to unravel the role of soil erosion for the carbon (C) budget from local to global scales. The main objective of this study was to determine SOC redistribution and the complete C budget of a loess soil affected by water erosion. We measured fluxes of SOC, dissolved organic C (DOC) and CO2 in a pseudo-replicated rainfall-simulation experiment. We characterized different C fractions in soils and redistributed sediments using density fractionation and determined C enrichment ratios (CER) in the transported sediments. Erosion, transport and subsequent deposition resulted in significantly higher CER of the sediments exported ranging between 1.3 and 4.0. In the exported sediments, C contents (mg per g soil) of particulate organic C (POC, C not bound to soil minerals) and mineral-associated organic C (MOC) were both significantly higher than those of non-eroded soils indicating that water erosion resulted in losses of C-enriched material both in forms of POC and MOC. The averaged SOC fluxes as particles (4.7 g C m−2 yr−1) were 18 times larger than DOC fluxes. Cumulative emission of soil CO2 slightly decreased at the erosion zone while increased by 56% and 27% at the transport and depositional zone, respectively, in comparison to non-eroded soil. Overall, CO2 emission is the predominant form of C loss contributing to about 90.5% of total erosion-induced C losses in our 4-month experiment, which were equal to 18 g C m−2. Nevertheless, only 1.5% of the total redistributed C was mineralized to CO2 indicating a large stabilization after deposition. Our study also underlines the importance of C losses by particles and as DOC for understanding the effects of water erosion on the C balance at the interface of terrestrial and aquatic ecosystems. PMID:24802350

  16. Remote sensing techniques for the detection of soil erosion and the identification of soil conservation practices

    NASA Technical Reports Server (NTRS)

    Pelletier, R. E.; Griffin, R. H.

    1985-01-01

    The following paper is a summary of a number of techniques initiated under the AgRISTARS (Agriculture and Resources Inventory Surveys Through Aerospace Remote Sensing) project for the detection of soil degradation caused by water erosion and the identification of soil conservation practices for resource inventories. Discussed are methods to utilize a geographic information system to determine potential soil erosion through a USLE (Universal Soil Loss Equation) model; application of the Kauth-Thomas Transform to detect present erosional status; and the identification of conservation practices through visual interpretation and a variety of enhancement procedures applied to digital remotely sensed data.

  17. The effect of wind erosion on toxic element content of soils based on wind tunnel trials

    NASA Astrophysics Data System (ADS)

    Tatárvári, Károly; Négyesi, Gábor

    2016-04-01

    Wind erosion causes enormous problems in many parts of the world. It damages the fertile layer of soils, and eventually wind erosion can transport materials, pathogens and these may cause medical problems in the respiratory system. Numerous international and Hungarian surveys have proved, that wind erosion not only affects loose textured soils. During droughts wind erosion may cause great damage in bound soils of clay in case these are over-cultivated and dusty. As an effect of climate change the duration and frequency of drought periods shall grow. In our investigation samples were taken from the upper 10 cms of soils of 5 various types of mechanical compounds (according to physical characteristics sand, clay, clay loam, loam, sandy loam) in Györ-Moson-Sopron County Hungary. According to the map of Hungary of the areas potentially affected by wind erosion the sand physical soil type is strongly endangered by wind erosion, other areas are moderatly endangered. According to most recent international classification areas belonging to the sand physical soil type are categorized as "endangered by wind erosion", and others belong to the category "not endangered by wind erosion", but these data were not based on local trials. When selecting the sampling areas it was taken to account that opencast sand and gravel mines are in operation in the area. Because of these recently significant wind erosion related phenomena were observed. The area is the most windy in the country. The mechanical composition, CaCO3 content, pH value (H2O,Kcl), humus content of the samples were defined. The wind erosion experiments were conducted in the wind tunnel of the University of Debrecen. The threshold velocities of the soils were measured, and the quantity of the soil transported by the wind was analyzed at four wind velocity value ranges. The transported material intercepted at different wind velocities at the height of 0-10 cm and 10-35 cm. The As, Ba, Cd, Co, Cr, Cu, Ni, Pb, and Zn

  18. Soil surface roughness: comparing old and new measuring methods and application in a soil erosion model

    NASA Astrophysics Data System (ADS)

    Thomsen, L. M.; Baartman, J. E. M.; Barneveld, R. J.; Starkloff, T.; Stolte, J.

    2015-04-01

    Quantification of soil roughness, i.e. the irregularities of the soil surface due to soil texture, aggregates, rock fragments and land management, is important as it affects surface storage, infiltration, overland flow, and ultimately sediment detachment and erosion. Roughness has been measured in the field using both contact methods (such as roller chain and pinboard) and sensor methods (such as stereophotogrammetry and terrestrial laser scanning (TLS)). A novel depth-sensing technique, originating in the gaming industry, has recently become available for earth sciences: the Xtion Pro method. Roughness data obtained using various methods are assumed to be similar; this assumption is tested in this study by comparing five different methods to measure roughness in the field on 1 m2 agricultural plots with different management (ploughing, harrowing, forest and direct seeding on stubble) in southern Norway. Subsequently, the values were used as input for the LISEM soil erosion model to test their effect on the simulated hydrograph at catchment scale. Results show that statistically significant differences between the methods were obtained only for the fields with direct seeding on stubble; for the other land management types the methods were in agreement. The spatial resolution of the contact methods was much lower than for the sensor methods (10 000 versus at least 57 000 points per square metre). In terms of costs and ease of use in the field, the Xtion Pro method is promising. Results from the LISEM model indicate that especially the roller chain overestimated the random roughness (RR) values and the model subsequently calculated less surface runoff than measured. In conclusion, the choice of measurement method for roughness data matters and depends on the required accuracy, resolution, mobility in the field and available budget. It is recommended to use only one method within one study.

  19. Soil surface roughness: comparing old and new measuring methods and application in a soil erosion model

    NASA Astrophysics Data System (ADS)

    Thomsen, L. M.; Baartman, J. E. M.; Barneveld, R. J.; Starkloff, T.; Stolte, J.

    2014-11-01

    Quantification of soil roughness, i.e. the irregularities of the soil surface due to soil texture, aggregates, rock fragments and land management, is important as it affects surface storage, infiltration, overland flow and ultimately sediment detachment and erosion. Roughness has been measured in the field using both contact methods, such as roller chain and pinboard, and sensor methods, such as stereophotogrammetry and terrestrial laser scanning (TLS). A novel depth sensing technique, originating in the gaming industry, has recently become available for earth sciences; the Xtion Pro method. Roughness data obtained using various methods are assumed to be similar; this assumption is tested in this study by comparing five different methods to measure roughness in the field on 1 m2 agricultural plots with different management (ploughing, harrowing, forest and direct seeding on stubble) in southern Norway. Subsequently, the values were used as input for the LISEM soil erosion model to test their effect on the simulated hydrograph on catchment scale. Results show that statistically significant differences between the methods were obtained only for the fields with direct drilling on stubble; for the other land management types the methods were in agreement. The spatial resolution of the contact methods was much lower than for the sensor methods (10 000 versus at least 57 000 points per m2 respectively). In terms of costs and ease of handling in the field, the Xtion Pro method is promising. Results from the LISEM model indicate that especially the roller chain underestimated the RR values and the model thereby calculated less surface runoff than measured. In conclusion: the choice of measurement method for roughness data matters and depends on the required accuracy, resolution, mobility in the field and available budget. It is recommended to use only one method within one study.

  20. A method for modeling the effects of climate and land use changes on erosion and sustainability of soil in a Mediterranean watershed (Languedoc, France).

    PubMed

    Paroissien, Jean-Baptiste; Darboux, Frédéric; Couturier, Alain; Devillers, Benoît; Mouillot, Florent; Raclot, Damien; Le Bissonnais, Yves

    2015-03-01

    Global climate and land use changes could strongly affect soil erosion and the capability of soils to sustain agriculture and in turn impact regional or global food security. The objective of our study was to develop a method to assess soil sustainability to erosion under changes in land use and climate. The method was applied in a typical mixed Mediterranean landscape in a wine-growing watershed (75 km(2)) within the Languedoc region (La Peyne, France) for two periods: a first period with the current climate and land use and a second period with the climate and land use scenarios at the end of the twenty-first century. The Intergovernmental Panel on Climate Change A1B future rainfall scenarios from the Météo France General circulation model was coupled with four contrasting land use change scenarios that were designed using a spatially-explicit land use change model. Mean annual erosion rate was estimated with an expert-based soil erosion model. Soil life expectancy was assessed using soil depth. Soil erosion rate and soil life expectancy were combined into a sustainability index. The median simulated soil erosion rate for the current period was 3.5 t/ha/year and the soil life expectancy was 273 years, showing a low sustainability of soils. For the future period with the same land use distribution, the median simulated soil erosion rate was 4.2 t/ha/year and the soil life expectancy was 249 years. The results show that soil erosion rate and soil life expectancy are more sensitive to changes in land use than to changes in precipitation. Among the scenarios tested, institution of a mandatory grass cover in vineyards seems to be an efficient means of significantly improving soil sustainability, both in terms of decreased soil erosion rates and increased soil life expectancies. PMID:25460424

  1. The contribution of mulches to control high soil erosion rates in vineyards in Eastern Spain

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Jordán, Antonio; Zavala, Lorena; José Marqués, María; Novara, Agata

    2014-05-01

    Soil erosion take place in degraded ecosystem where the lack of vegetation, drought, erodible parent material and deforestation take place (Borelli et al., 2013; Haregeweyn et al., 2013; Zhao et al., 2013). Agriculture management developed new landscapes (Ore and Bruins, 2012) and use to trigger non-sustainable soil erosion rates (Zema et al., 2012). High erosion rates were measured in agriculture land (Cerdà et al., 2009), but it is also possible to develop managements that will control the soil and water losses, such as organic amendments (Marqués et al., 2005), plant cover (Marqués et al., 2007) and geotextiles (Giménez Morera et al., 2010). The most successful management to restore the structural stability and the biological activity of the agriculture soil has been the organic mulches (García Orenes et al; 2009; 2010; 2012). The straw mulch is also very successful on bare fire affected soil (Robichaud et al., 2013a; 2013b), which also contributes to a more stable soil moisture content (García-Moreno et al., 2013). The objective of this research is to determine the impact of two mulches: wheat straw and chipped branches, on the soil erosion rates in a rainfed vineyard in Eastern Spain. The research site is located in the Les Alcusses Valley within the Moixent municipality. The Mean annual temperature is 13 ºC, and the mean annual rainfall 455 mm. Soil are sandy loam, and are developed at the foot-slope of a Cretaceous limestone range, the Serra Grossa range. The soils use to be ploughed and the features of soil erosion are found after each thunderstorm. Rills are removed by ploughing. Thirty rainfall simulation experiments were carried out in summer 2011 during the summer drought period. The simulated rainfall lasted during 1 hour at a 45 mmh-1 intensity on 1 m2 plots (Cerdà and Doerr, 2010; Cerdà and Jurgensen 2011). Ten experiments were carried out on the control plots (ploughed), 10 on straw mulch covered plots, and 10 on chipped branches covered

  2. Bare soil erosion modelling with rainfall simulations: experiments on crop and recently burned areas

    NASA Astrophysics Data System (ADS)

    Catani, F.; Menci, S.; Moretti, S.; Keizer, J.

    2006-12-01

    The use of numerical models is of fundamental importance in the comprehension and prediction of soil erosion. At the very basis of the calibration process of the numerical models are the direct measurements of the governing parameters, carried out during field or laboratory tests. To measure and model soil erosion rainfall simulations can be used, that allow the reproduction of project rainfall having chosen characteristics of intensity and duration. The main parameters that rainfall simulators can measure are hydraulic conductivity, parameters of soil erodibility, rate and features of splash erosion, discharge coefficient and sediment yield. Other important parameters can be estimated during the rainfall simulations through the use of photogrammetric instruments able to memorize high definition stereographic models of the soil plot under analysis at different time steps. In this research rainfall simulator experiments (rse) were conducted to measure and quantify runoff and erosion processes on selected bare soil plots. The selected plots are located in some vineyards, olive groves and crops in central Italy and in some recently burned areas in north-central Portugal, affected by a wildfire during early July 2005 and, at the time, largely covered by commercial eucalypt plantations. On the Italian crops the choice of the rainfall intensities and durations were performed on the basis of the previous knowledge of the selected test areas. The procedure was based on an initial phase of soil wetting and a following phase of 3 erosion cycles. The first should reproduce the effects of a normal rainfall with a return time of 2 years (23 mm/h). The second should represent a serious episode with a return time of 10 years (34 mm/h). The third has the objective to reproduce and understand the effects of an intense precipitation event, with a return time of 50 years (41 mm/h). During vineyards experiments some photogrammetric surveys were carried out as well. In the Portugal

  3. Analysis of shallow landslides and soil erosion induced by rainfall over large areas

    NASA Astrophysics Data System (ADS)

    Cuomo, Sabatino; Della Sala, Maria

    2014-05-01

    Due to heavy rainstorms, steep hillslopes may be affected by either shallow landslides or soil superficial erosion (Acharya et al., 2011), which originate different flow-like mass movements in adjacent or overlapping source areas (Cascini et al., 2013). Triggering analysis (Cascini et al., 2011) is a relevant issue for hazard assessment that is, in turn, the first step of risk analysis procedures (Fell et al., 2008). Nevertheless, the available approaches separately consider shallow landslides and soil erosion. Specifically, quantitative models for landslides triggering analysis allow simulating the physical processes leading to failure such as pore water pressure increase and soil shear mobilization and provide estimates of the amount of material potentially involved; however, success of quantitative methods must be carefully evaluated in complex geological setting as recently outlined (Sorbino et al., 2010) and further applications to real case histories are straightforward. On the other hand, a wide range of models exist for soil erosion analysis, which differ in terms of complexity, processes considered and data required for the model calibration and practical applications; in particular, quantitative models can estimate the source areas and the amount of eroded soil through empirical relationships or mathematical equations describing the main physical processes governing soil erosion (Merritt et al., 2003). In this work a spatially distributed analysis is proposed for testing the potentialities of two available models to respectively investigate the spatial occurrence of first-time shallow landslides and superficial soil erosion repeatedly occurring in a large test area of the Southern Italy. Both analyses take into account the seasonal variation of soil suction, rainfall characteristics and soil cover use (Cuomo and Della Sala, 2013). The achieved results show that the source areas of shallow landslides strongly depend on rainfall intensity and duration and

  4. Variable rainfall intensity during soil erosion experiments at the laboratory rainfall simulator

    NASA Astrophysics Data System (ADS)

    Laburda, Tomas; Schwarzova, Pavla; Krasa, Josef

    2016-04-01

    Experimental research of soil erosion at the laboratory rainfall simulator at the CTU in Prague continued with 11th soil set Trebesice III in 2014/2015. Standard simulations with constant rainfall intensity were complemented by additional simulations with variable rainfall intensity with two different patterns. The main objective was to determine the feasibility of these experiments and the effect on erosion characteristics compared to those with constant rainfall intensity. This measurement consist of 60 minute simulations (change in intensity in 20. and 40. minute of simulation) with increasing rainfall intensity with pattern of 20-40-60 mm/hr ("inc") and decreasing intensity with pattern of 60-40-20 mm/hr ("dec") which have been compared with experiments with constant rainfall intensity of 40 mm/hr ("c40"). All experiments thus reaching the same total precipitation during entire simulation. This comparison was done on soil sample with dimensions of 4x0,9x0,15 meters and slope adjusted at 4° and 8°. Final evaluation consists of comparison of development and cumulative values of surface runoff and soil loss. In case of steady soil conditions (in this case, the experiments on the slope 4°) results show there is no significant difference in surface runoff in term of cumulative values and development (in the middle period of simulations with rainfall intensity of 40 mm/hr, i.e. 20-40. minute of every experiment) between "c40", "inc" and "dec". On the other hand, results of soil loss from the same experiments differ according to rainfall intensity pattern in both development and cumulative values. While "inc" experiment has slightly lower (up to 10 %) soil loss than "c40", development of soil loss (in the middle period of simulations with 40 mm/hr) of "dec" experiment is almost two times lower compare to "c40". Experiments with longitudinal soil surface of 8° differ in soil moisture that affects results more than variable rainfall intensity pattern. Experimental

  5. Analysis of Actual Soil Degradation by Erosion Using Satellite Imagery and Terrain Attributes in the Czech Republic

    NASA Astrophysics Data System (ADS)

    Zizala, Daniel

    2015-04-01

    Soil water and wind erosion (possibly tillage erosion) is the most significant soil degradation factor in the Czech Republic. Moreover, this phenomenon also affects seriously quality of water sources., About 50 % of arable land are endangered by water erosion and about 10 % of arable land are endangered wind erosion in the Czech Republic. These processes have been accelerated by human activity. Specific condition of agriculture land in the Czech Republic including highland relief and particularly size of land parcel and intensification of agriculture does not enable to reduce flow of runoff water. Insufficient protection against accelerated erosion processes is related to lack of landscape and hydrographic elements and large area of agricultural plots. Currently, this issue is solved at plot scale by field investigation or at regional scale using numerical and empirical erosion models. Nevertheless, these models enable only to predict the potential of soil erosion. Large scale assessment of actual degradation level of soils is based on expert knowledge. However, there are still many uncertainties in this issue. Therefore characterization of actual degradation level of soil is required especially for assessment of long-term impact of soil erosion on soil fertility. Soil degradation by erosion can be effectively monitored or quantified by modern tools of remote sensing with variable level of detail accessible. Aims of our study is to analyse the applicability of remote sensing for monitoring of actual soil degradation by erosion. Satellite and aerial image data (multispectral and hyperspectral), terrain attributes and data from field investigation are the main source for this analyses. The first step was the delimitation of bare soils using supervised classification of the set of Landsat scenes from 2000 - 2014. The most suitable period of time for obtaining spectral image data with the lowest vegetation cover of soil was determined. The results were verified by

  6. Combined effect of soil erosion and climate change induces abrupt changes in soil and vegetation properties in semiarid Mediterranean shrublands.

    NASA Astrophysics Data System (ADS)

    Bochet, Esther; García-Fayos, Patricio

    2013-04-01

    Semiarid Mediterranean ecosystems are experiencing major alterations as a result of the complex interactions between climatic fluctuations and disturbances caused by human activities. Future scenarios of global change forecast a rapid degradation of these ecosystems, with a reduction of their functionality, as a result of changes in relevant vegetation and soil properties. Some theoretical models indicate that these ecosystems respond non-linearly to regular variations in the external conditions, with an abrupt shift when conditions approach a certain critical level or threshold. Considering these predictions, there is an urgent need to know the effects that these alterations might have on semi-arid ecosystems and their components. In this study, we aim at analyzing the consequences of climate change and increasing soil erosion on soil and vegetation properties and the functional dynamics of semiarid Mediterranean shrublands. We predict that the combined effect of both drivers will be additive or synergistic, increasing the negative effects of each one. We compared vegetation and soil properties of flat areas (low erosion) and steep hillslopes (high erosion) in two climatic areas (484 mm and 10.3°C, and 368mm and 11.9°C, respectively) that reproduce the predicted climate change in temperature and precipitation for the next 40 years. Species richness, vegetal cover, plant life-form composition were determined in 20 m2 plots and soil was sampled in the same plots to determine bulk density, aggregate stability, fertility and water holding capacity. All soil and vegetation properties were negatively affected by soil erosion and climate change. However, contrary to our hypothesis, the joined effect of both drivers on all soil and vegetation properties was antagonistic, except for the vegetal cover that showed an additive response to their interaction. Our results evidence that soil erosion affects more negatively the soil and vegetation properties in the cooler and

  7. Application of remote sensing to estimating soil erosion potential

    NASA Technical Reports Server (NTRS)

    Morris-Jones, D. R.; Kiefer, R. W.

    1980-01-01

    A variety of remote sensing data sources and interpretation techniques has been tested in a 6136 hectare watershed with agricultural, forest and urban land cover to determine the relative utility of alternative aerial photographic data sources for gathering the desired land use/land cover data. The principal photographic data sources are high altitude 9 x 9 inch color infrared photos at 1:120,000 and 1:60,000 and multi-date medium altitude color and color infrared photos at 1:60,000. Principal data for estimating soil erosion potential include precipitation, soil, slope, crop, crop practice, and land use/land cover data derived from topographic maps, soil maps, and remote sensing. A computer-based geographic information system organized on a one-hectare grid cell basis is used to store and quantify the information collected using different data sources and interpretation techniques. Research results are compared with traditional Universal Soil Loss Equation field survey methods.

  8. Quantification soil production and erosion using isotopic techniques

    NASA Astrophysics Data System (ADS)

    Dosseto, Anthony; Suresh, P. O.

    2010-05-01

    Soil is a critical resource, especially in the context of a rapidly growing world's population. Thus, it is crucial to be able to quantify how soil resources evolve with time and how fast they become depleted. Over the past few years, the application of cosmogenic isotopes has permitted to constrain rates of soil denudation. By assuming constant soil thickness, it is also possible to use these denudation rates to infer soil production rates (Heimsath et al. 1997). However, in this case, it is not possible to discuss any imbalance between erosion and production, which is the core question when interested in soil resource sustainability. Recently, the measurement of uranium-series isotopes in soils has been used to quantify the residence time of soil material in the weathering profile and to infer soil production rates (Dequincey et al. 2002; Dosseto et al. 2008). Thus, the combination of U-series and cosmogenic isotopes can be used to discuss how soil resources evolve with time, whether they are depleting, increasing or in steady-state. Recent work has been undertaken in temperate southeastern Australia where a several meters thick saprolite is developed over a graniodioritc bedrock and underlains a meter or less of soil (Dosseto et al., 2008) and in tropical Puerto Rico, also in a granitic catchment. Results show that in an environment where human activity is minimal, soil and saprolite are renewed as fast as they are destroyed through denudation. Further work is investigating these processes at other sites in southeastern Australia (Frogs Hollow; Heimsath et al. 2001) and Puerto Rico (Rio Mameyes catchment; andesitic bedrock). Results will be presented and a review of the quantification of the rates of soil evolution using isotopic techniques will be given. Dequincey, O., F. Chabaux, et al. (2002). Chemical mobilizations in laterites: Evidence from trace elements and 238U-234U-230Th disequilibria. Geochim. Cosmochim. Acta 66(7): 1197-1210. Dosseto, A., S. P

  9. Soil carbon and nitrogen erosion in forested catchments: implications for erosion-induced terrestrial carbon sequestration

    NASA Astrophysics Data System (ADS)

    Stacy, E. M.; Hart, S. C.; Hunsaker, C. T.; Johnson, D. W.; Berhe, A. A.

    2015-08-01

    Lateral movement of organic matter (OM) due to erosion is now considered an important flux term in terrestrial carbon (C) and nitrogen (N) budgets, yet most published studies on the role of erosion focus on agricultural or grassland ecosystems. To date, little information is available on the rate and nature of OM eroded from forest ecosystems. We present annual sediment composition and yield, for water years 2005-2011, from eight catchments in the southern part of the Sierra Nevada, California. Sediment was compared to soil at three different landform positions from the source slopes to determine if there is selective transport of organic matter or different mineral particle size classes. Sediment export varied from 0.4 to 177 kg ha-1, while export of C in sediment was between 0.025 and 4.2 kg C ha-1 and export of N in sediment was between 0.001 and 0.04 kg N ha-1. Sediment yield and composition showed high interannual variation. In our study catchments, erosion laterally mobilized OM-rich litter material and topsoil, some of which enters streams owing to the catchment topography where steep slopes border stream channels. Annual lateral sediment export was positively and strongly correlated with stream discharge, while C and N concentrations were both negatively correlated with stream discharge; hence, C : N ratios were not strongly correlated to sediment yield. Our results suggest that stream discharge, more than sediment source, is a primary factor controlling the magnitude of C and N export from upland forest catchments. The OM-rich nature of eroded sediment raises important questions about the fate of the eroded OM. If a large fraction of the soil organic matter (SOM) eroded from forest ecosystems is lost during transport or after deposition, the contribution of forest ecosystems to the erosion-induced C sink is likely to be small (compared to croplands and grasslands).

  10. Development of a Common Water and Wind Erosion Model for Soil Conservation Planning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land management can greatly impact soil erosion caused by the forces of water and/or wind. Erosion prediction in the United States has followed two separate development paths. Early tools developed were the Universal Soil Loss Equation and the Wind Erosion Equation, and this separation continued thr...

  11. Impact of wind erosion on soils in arid and semi-arid landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion is a significant aeolian process that produces many effects on the soils and landscapes in dryland systems, comprising almost forty percent of the Earth’s land surface. Wind erosion often occurs when coarse-textured soils are bare, loose, dry and subjected to erosive winds. Although w...

  12. Development of a common water and wind erosion model for soil conservation planning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land management can greatly impact soil erosion caused by the forces of water and/or wind. Erosion prediction in the United States has followed two separate development paths. Early tools developed were the Universal Soil Loss Equation and the Wind Erosion Equation, and this separation continued thr...

  13. Erosion effects on water and DOC/DIC fluxes in soils from a hummocky ground moraine landscape

    NASA Astrophysics Data System (ADS)

    Herbrich, Marcus; Gerke, Horst H.; Sommer, Michael

    2015-04-01

    In the arable hummocky ground moraine soil landscape, an erosion-induced spatial differentiation of soil types can be observed. Unknown is how the water flow and solute transport is affected by soil-crop interactions depending on properties of differently-developed soil horizons. The objective was to analyze these interactions and by comparing lysimeter-based measured water and solute balances for Luvisol soil monoliths extracted from differently-eroded slope locations. For a 3-years measurement period, differences in cumulative seepage water drainage of more than 76 % were observed between most and least eroded Luvisol. Although the soil types were identical, these data indicated characteristic erosion-induced spatial differentiation in the water balance of the landscape. Because the concentrations of dissolved organic carbon (DOC) and of dissolved inorganic carbon (DIC) were relatively similar for all lysimeters at the bottom (1.4 m soil depth), the DOC/DIC leaching was dominated by differences in water fluxes in this observation period (04/2011-04/2014). Results suggest that water and solute balances are depending on the degree of erosion-induced soil profile modifications. Hence for the landscape scale analysis of the landscape water and solute balances, not only the distributed soil types but also erosion-induced modifications with a single soil type should be considered.

  14. The effects of mulching on soil erosion by water. A review based on published data

    NASA Astrophysics Data System (ADS)

    Prosdocimi, Massimo; Jordán, Antonio; Tarolli, Paolo; Cerdà, Artemi

    2016-04-01

    Among the soil conservation practices that have been recently implemented, mulching has been successfully applied in different contexts (Jordán et al., 2011), such as agricultural lands (García-Orenes et al. 2009; Prosdocimi et al., 2016), fire-affected areas (Prats et al., 2014; Robichaud et al., 2013) and anthropic sites (Hayes et al., 2005), to reduce water and soil losses rates. In these contexts, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas of the world (Cerdà et al., 2009; Cerdan et al., 2010; Sadeghi et al., 2015). Although soil erosion by water consists of physical processes that vary significantly in severity and frequency according to when and where they occur, they are also strongly influenced by anthropic factors such as unsustainable farming practices and land-use changes on large scales (Cerdà, 1994; Montgomery, 2007). Although the beneficial effects of mulching are known, their quantification needs further research, especially in those areas where soil erosion by water represents a severe threat. In literature, there are still some uncertainties about how to maximize the effectiveness of mulching in the reduction of soil and water loss rates. First, the type of choice of the vegetative residues is fundamental and drives the application rate, cost, and consequently, its effectiveness. Second, it is important to assess application rates suitable for site-specific soil and environment conditions. The percentage of area covered by mulch is another important aspect to take into account, because it has proven to influence the reduction of soil loss. And third, the role played by mulching at catchment scale, where it plays a key role as barrier for breaking sediment and runoff connectivity. Given the seriousness of soil erosion by water and the uncertainties that still concern the correct use of mulching, this work aims to evaluate the effects of mulching on soil erosion rates and water losses in agricultural

  15. Physically-based quantitative analysis of soil erosion induced by heavy rainfall on steep slopes

    NASA Astrophysics Data System (ADS)

    Della Sala, Maria; Cuomo, Sabatino; Novità, Antonio

    2014-05-01

    Heavy rainstorms cause either shallow landslides or soil superficial erosion in steep hillslopes covered by coarse unsaturated soils (Cascini et al., 2013), even over large areas (Cuomo and Della Sala, 2013a). The triggering stage of both phenomena is related to ground infiltration, runoff and overland flow (Cuomo and Della Sala, 2013), which are key processes to be investigated. In addition, the mobilization of solid particles deserves a proper physical-based modeling whether a quantitative estimation of solid particles discharge at the outlet of mountain basin is required. In this work, the approaches for soil superficial erosion analysis are firstly reviewed; then, a relevant case study of two medium-sized mountain basins, affected by flow-like phenomena with huge consequences (Cascini et al., 2009) is presented, which motivates a parametric numerical analysis with a physically-based model carried out for a wide class of soil properties and rainfall scenarios (Cuomo et al., 2013b). The achieved results outline that the peak discharge of water and solid particles driven by overland flow depends on rainfall intensity while volumetric solid concentration within the washout is related to the morphometric features of the whole mountain basin. Furthermore, soil suction is outlined as a key factor for the spatial-temporal evolution of infiltration and runoff in the basin, also affecting the discharge of water and solid particles at the outlet of the basin. Based on these insights, selected cases are analyzed aimed to provide a wide class of possible slope erosion scenarios. It is shown that, provided the same amount of cumulated rainfall, the sequence of high and low intensity rainfall events strongly affects the time-discharge at the outlet of the basin without significant variations of the maximum volumetric solid concentration. References Cascini, L., Cuomo, S., Ferlisi, S., Sorbino, G. (2009). Detection of mechanisms for destructive landslides in Campania region

  16. Modelling the effect of agricultural management practices on soil organic carbon stocks: does soil erosion matter?

    NASA Astrophysics Data System (ADS)

    Nadeu, Elisabet; Van Wesemael, Bas; Van Oost, Kristof

    2014-05-01

    Over the last decades, an increasing number of studies have been conducted to assess the effect of soil management practices on soil organic carbon (SOC) stocks. At regional scales, biogeochemical models such as CENTURY or Roth-C have been commonly applied. These models simulate SOC dynamics at the profile level (point basis) over long temporal scales but do not consider the continuous lateral transfer of sediment that takes place along geomorphic toposequences. As a consequence, the impact of soil redistribution on carbon fluxes is very seldom taken into account when evaluating changes in SOC stocks due to agricultural management practices on the short and long-term. To address this gap, we assessed the role of soil erosion by water and tillage on SOC stocks under different agricultural management practices in the Walloon region of Belgium. The SPEROS-C model was run for a 100-year period combining three typical crop rotations (using winter wheat, winter barley, sugar beet and maize) with three tillage scenarios (conventional tillage, reduced tillage and reduced tillage in combination with additional crop residues). The results showed that including soil erosion by water in the simulations led to a general decrease in SOC stocks relative to a baseline scenario (where no erosion took place). The SOC lost from these arable soils was mainly exported to adjacent sites and to the river system by lateral fluxes, with magnitudes differing between crop rotations and in all cases lower under conservation tillage practices than under conventional tillage. Although tillage erosion plays an important role in carbon redistribution within fields, lateral fluxes induced by water erosion led to a higher spatial and in-depth heterogeneity of SOC stocks with potential effects on the soil water holding capacity and crop yields. This indicates that studies assessing the effect of agricultural management practices on SOC stocks and other soil properties over the landscape should

  17. Historical Influence of Soil and Water Management on Carbon Erosion and Burial in the United States

    NASA Astrophysics Data System (ADS)

    Sundquist, E. T.; Visser Ackerman, K.; Stallard, R. F.; Bliss, N. B.

    2012-04-01

    begin with estimates of the carbon content of soils at erosional and depositional sites. Rates of soil carbon production, erosion, degradation, transport, and burial are constrained by both sediment and carbon mass balances coupled to representations of landscape soil-carbon dynamics. We calculate rates of carbon burial in aquatic environments from estimates of composition and deposition rates of autochthonous and allochthonous sediment. We find that cumulative amounts of carbon affected by historical erosion and deposition are comparable to amounts of cumulative soil carbon depletion estimated in previous studies that have not considered erosion and deposition. Our historical sediment budget scenarios imply a large historical transient of eroded and redeposited terrestrial sediments. An improved understanding of non-steady-state carbon dynamics in these sediments and in their incipient soils is needed to estimate the net effect of erosion and deposition on the historical and present-day exchange of carbon between the land and the atmosphere. The transient sediment pulse and accompanying biogeochemical and ecological responses have broad implications for management of water and ecosystems.

  18. Effect of soil erosion on the long-term stability of FUSRAP near-surface waste-burial sites

    SciTech Connect

    Knight, M.J.

    1983-04-01

    Decontamination of FUSRAP sites could result in the generation of large volumes (in excess of 400,000 m/sup 3/) of low-activity radioactive wastes (primarily contaminated soil and building materials) requiring subsequent disposal. It is likely that near-surface burial will be seriously considered as an option for disposal of these materials. A number of factors - including soil erosion - could adversely affect the long-term stability of a near-surface waste-burial site. The majority of FUSRAP sites are located in the humid eastern United States, where the principal cause of erosion is the action of water. This report examines the effect of soil erosion by water on burial-site stability based on analysis of four hypothetical near-surface burial sites. The Universal Soil Loss Equation was employed to estimate average annual soil loss from burial sites and the 1000-year effects of soil loss on the soil barrier (burial trench cap) placed over low-activity wastes. Results suggest that the land use of the burial site and the slope gradient of the burial trench cap significantly affect the rate of soil erosion. The development of measures limiting the potential land use of a burial site (e.g., mixing large rocks into the burial trench cap) may be required to preserve the integrity of a burial trench for long periods of time.

  19. 75 FR 75961 - Notice of Implementation of the Wind Erosion Prediction System for Soil Erodibility System...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-07

    ... Soil Erodibility System Calculations for the Natural Resources Conservation Service AGENCY: Natural...) for soil erodibility system calculations scheduled for implementation for public review and comment... computer model that predicts soil erosion via simulation of the fundamental processes controlling...

  20. Influence of development stage and disturbance of physical and biological soil crusts on soil water erosion

    NASA Astrophysics Data System (ADS)

    Chamizo, S.; Cantón, Y.; Lázaro, R.; Solé-Benet, A.; Calvo-Cases, A.; Miralles, I.; Domingo, F.

    2009-04-01

    Most soils exposed to rainfall are prone to sealing and crusting processes causing physical soil crusts (PSCs). When climate and soil stability conditions are suitable, PSCs can be consolidated by a complex community consisting of cyanobacteria, bacteria, green algae, microfungi, lichens and bryophytes, which are collectively known as biological soil crust (BSC). The influence of soil crusts on erosion processes is complex: crusts may reduce detachment, increasing soil stability and protecting soil against raindrop impact, although that protection will depend on the type of soil crust and the stage of development; they can also build up runoff, suggesting that downstream erosion may actually be increased or favoured water harvesting to vegetated areas. On the other hand, BSCs have been demonstrated to be very vulnerable to disturbance which in turn can lead to accelerate soil erosion and other forms of land degradation. Incorporation of the response of different type of soil crusts and the effects of their disturbance is highly likely to improve the prediction of runoff and water erosion models in arid and semi-arid catchments. The objective of this work is to analyse the erosional response of PSCs and BSCs in different stages of their development and subject to distinct disturbances when extreme rainfalls intensities are applied at plot scale in semiarid environments. Small plots on the most representative crust types, corresponding to different stages of crust development, in two semiarid ecosystems in SE Spain, El Cautivo (in the Tabernas Desert) and Amoladeras (in the Natural Park Cabo de Gata-Níjar), were selected and three disturbance treatments were applied on each crust type: a) no disturbance (control), b) trampling, stepping 100 times over the crust and c) scraping. Two consecutive rainfall simulation experiments (50 mm/h rainfall intensity) were carried out on each plot: the first on dry soil and the second, 30 minutes later, on wet soil conditions

  1. Influence of soil erosion on CO2 exchange within the CarboZALF manipulation experiment

    NASA Astrophysics Data System (ADS)

    Hoffmann, Mathias; Augustin, Jürgen; Sommer, Michael

    2014-05-01

    Agriculture in the hummocky ground moraine landscape of NE-Germany is characterized by an increase in energy crop cultivation, like maize or sorghum. Both enhance lateral C fluxes by erosion and induce feedbacks on C dynamics of agroecosystems as a result of the time limited land cover and the vigorous crop growth. However, the actual impact of these phenomena on the CO2-sink/-source function of agricultural landscapes, is still not clear. Therefore we established the interdisciplinary project 'CarboZALF' in 2009. In our field experiment CarboZALF-D we are monitoring CO2 fluxes for soil-plant systems, which cover all landscape relevant soil states in respect to erosion and deposition, like Albic Cutanic Luvisol, Calcic Cutanic Luvisol, Calcaric Regosol and Endogleyic Colluvic Regosol. Furthermore, we induced erosion / deposition in a manipulation experiment. Automated chamber systems (2.5 m, basal area 1 m2, transparent) are placed at the manipulated sites as well as at one site neither influenced by erosion, nor by deposition. CO2 flux modelling of high temporal resolution includes ecosystem respiration (Reco), gross primary productivity (GPP) and net ecosystem exchange (NEE) based on parallel and continuous measurements of the CO2 exchange, soil and air temperatures as well as photosynthetic active radiation (PAR). Modelling includes gap filling which is needed in case of chamber malfunctions and abrupt disturbances by farming practice. In our presentation we would like to show results of the CO2 exchange measurements for one year. Differences are most pronounced between the non-eroded and the colluvial soil: The Endogleyic Colluvic Regosol showed higher flux rates for Reco and NEE compared to the Albic Cutanic Luvisol. The eroded soil (Calcic Cutanic Luvisol) demonstrated CO2fluxes intermediate between the non-affected and depositional site. Site-specific consequences for the soil C stocks will be also discussed in the presentation.

  2. Estimation of soil loss by water erosion in the Chinese Loess Plateau using Universal Soil Loss Equation and GRACE

    NASA Astrophysics Data System (ADS)

    Schnitzer, S.; Seitz, F.; Eicker, A.; Güntner, A.; Wattenbach, M.; Menzel, A.

    2013-06-01

    For the estimation of soil loss by erosion in the strongly affected Chinese Loess Plateau we applied the Universal Soil Loss Equation (USLE) using a number of input data sets (monthly precipitation, soil types, digital elevation model, land cover and soil conservation measures). Calculations were performed in ArcGIS and SAGA. The large-scale soil erosion in the Loess Plateau results in a strong non-hydrological mass change. In order to investigate whether the resulting mass change from USLE may be validated by the gravity field satellite mission GRACE (Gravity Recovery and Climate Experiment), we processed different GRACE level-2 products (ITG, GFZ and CSR). The mass variations estimated in the GRACE trend were relatively close to the observed sediment yield data of the Yellow River. However, the soil losses resulting from two USLE parameterizations were comparatively high since USLE does not consider the sediment delivery ratio. Most eroded soil stays in the study area and only a fraction is exported by the Yellow River. Thus, the resultant mass loss appears to be too small to be resolved by GRACE.

  3. Soil erosion after forest fires in the Valencia region

    NASA Astrophysics Data System (ADS)

    González-Pelayo, Óscar; Keizer, Jan Jacob; Cerdà, Artemi

    2014-05-01

    Soil erosion after forest fire is triggered by the lack of vegetation cover and the degradation of the physical, biological and chemical properties (Martí et al., 2012; Fernández et al., 2012; Guénon, 2013). Valencia region belongs to the west Mediterranean basin ("Csa", Köppen climate classification), with drought summer periods that enhance forest fire risk. The characteristics of the climate, lithology and land use history makes this region more vulnerable to soil erosion. In this area, fire recurrence is being increased since late 50s (Pausas, 2004) and post-fire erosion studies became more popular from 80's until nowadays (Cerdá and Mataix-Solera, 2009). Research in Valencia region has contributed significantly to a better understanding of the effect of spatial and temporal scale on runoff and sediment yield measurements. The main achievements concerns: a) direct measurement of erosion rates under a wide range of methodologies (natural vs simulated rainfall, open vs closed plots); from micro- to meso-plot and catchment scale in single (Rubio et al., 1994; Cerdà et al., 1995; Cerdà 1998a; 1998b; Llovet et al., 1998; Cerdà, 2001; Calvo-Cases et al., 2003; Andreu et al., 2001; Mayor et al., 2007; Cerdà and Doerr, 2008) and multiples fires (Campo et al., 2006; González-Pelayo et al., 2010a). Changes in soil properties (Sanroque et al., 1985; Rubio et al., 1997; Boix-Fayós, 1997; Gimeno-Garcia et al., 2000; Guerrero et al., 2001; Mataix-Solera et al., 2004; González-Pelayo et al., 2006; Arcenegui et al., 2008; Campo et al., 2008; Bodí et al., 2012), in post-fire vegetation patterns (Gimeno-García et al., 2007) and, studies on mitigation strategies (Bautista et al., 1996; Abad et al., 2000). b) Progress to understanding post-fire erosion mechanism and sediment movement (Boix-Fayós et al., 2005) by definition of thresholds for sediment losses; fire severity, slope angle, bedrock, rain characteristics, vegetation pattern and ecosystem resilience (Mayor

  4. Reduction Potato s hydric soil erosion using space technology

    NASA Astrophysics Data System (ADS)

    Guyot, E.; Rios, V.; Zelaya, D.; Rios, E.; Lepen, F.; Padilla, P.; Soria, F.

    The potato's crop has an econ omic importance in Tucuman's agricultural PBI (Gross Product Income) because its rank is fourth(4°). Production's potato area is a breakable agro system; its geographic location is in Pedemonte's agro-ecological region so is essential to handle hydric erosion. Therefore, the aim of this work is improve crop's potato irrigation management through satellite information merge with farm's practices. The space technology consented to obtain Digital Model Soil using both unique differential and dual frequency GPS signals and total station. The irrigation practices were carried out due to irrigation management (FAO) and satellite imagine software (ENVI). Preliminary results of this experience allowed to follow the crop's growing through multitemporal study; reprogramming farm's irrigation practices intended for manage reduction hydric erosion and heighten economically its productivity for the next period

  5. Extreme soil erosion events: an opportunity for promoting awareness for soil conservation

    NASA Astrophysics Data System (ADS)

    Eshel, G.; Egozi, R.

    2012-04-01

    As the world population continues to grow, the need for food production increases, which result in larger areas under intensive agriculture activity. It is also known that intensive agriculture activity tends to accelerate soil erosion rates. The coupling of these two processes put under risk the fertile soils and the ability to maintain sustainable food production. However, the subject is still ignored by the general public and politicians, contrary to global warming and water scarcity issues. The main reason may relate to the difficulty in providing numbers for slow long term soil erosion process. This is due to measurements complexity to quantify small changes in volume, especially, when the soils are deep and frequently cultivated. On the other hand, extreme soil erosion events provide us a unique opportunity to measure soil loss rates and quantities under real conditions in which soil erosion processes are intensified. Although those events provide good imagery of the problem, it is not trivial to extract quantitative valuable information. We, the scientists from different disciplines, must join forces in order to develop tools to overcome the problem. If we able to generate more significant scientific knowledge on the phenomena, we may able to raise the general public and politicians awareness for the need to change the way we manage our land and extensively shift toward conservation practices.

  6. Patch burning: implications on water erosion and soil properties.

    PubMed

    Ozaslan Parlak, Altingul; Parlak, Mehmet; Blanco-Canqui, Humberto; Schacht, Walter H; Guretzky, John A; Mamo, Martha

    2015-05-01

    Patch burning can be a potential management tool to create grassland heterogeneity and enhance forage productivity and plant biodiversity, but its impacts on soil and environment have not been widely documented. In summer 2013, we studied the effect of time after patch burning (4 mo after burning [recently burned patches], 16 mo after burning [older burned patches], and unburned patches [control]) on vegetative cover, water erosion, and soil properties on a patch-burn experiment established in 2011 on a Yutan silty clay loam near Mead, NE. The recently burned patches had 29 ± 8.0% (mean ± SD) more bare ground, 21 ± 1.4% less canopy cover, and 40 ± 11% less litter cover than older burned and unburned patches. Bare ground and canopy cover did not differ between the older burned and unburned patches, indicating that vegetation recovered. Runoff depth from the older burned and recently burned patches was 2.8 times (19.6 ± 4.1 vs. 7.1 ± 3.0 mm [mean ± SD]) greater than the unburned patches. The recently burned patches had 4.5 times greater sediment loss (293 ± 89 vs. 65 ± 56 g m) and 3.8 times greater sediment-associated organic C loss (9.2 ± 2.0 vs. 2.4 ± 1.9 g m) than the older burned and unburned patches. The recently burned patches had increased daytime soil temperature but no differences in soil compaction and structural properties, dissolved nutrients, soil C, and total N concentration relative to older burned and unburned patches. Overall, recently burned patches can have reduced canopy and litter cover and increased water erosion, but soil properties may not differ from older burn or unburned patches under the conditions of this study. PMID:26024270

  7. Using 137Cs technique to quantify soil erosion and deposition rates in an agricultural catchment in the black soil region, Northeast China

    NASA Astrophysics Data System (ADS)

    Fang, Haiyan; Sun, Liying; Qi, Deli; Cai, Qiangguo

    2012-10-01

    Soil erosion significantly affects the productive black soil region in Northeast China. Quantification of the soil erosion is necessary for designing efficient degradation control strategies. 137Cs measurements undertaken on 61 sampling points collected within a 28.5 ha agricultural catchment in the black soil region of Northeast China were used to establish the magnitude and spatial pattern of soil redistribution rates as well as sediment budget within the catchment. Estimated soil redistribution rates using the Mass Balance Model 2 (MBM2) ranged from - 56.8 to 171.4 t ha- 1 yr- 1 for the sampling points that were verified by means of both runoff plot data and pedological investigation. Erosion generally occurred behind the shelterbelts, especially in the ephemeral gully susceptible areas, while deposition mainly occurred along the shelterbelts and at the catchment outlet. In the study catchment, 69% of the eroded sediments came from the slopes and 31% the ephemeral gullies. Sediments deposited along the shelterbelts at a rate of ca. 78 t yr- 1 and ca. 33 t yr- 1 at the catchment outlet. The gross soil loss rate for the catchment was - 4.4 t ha- 1 yr- 1 with a sediment delivery ratio of 53%. The mean rate of - 14.5 t ha- 1 yr- 1 in the erosion areas was much higher than the tolerable value, suggesting that effective soil conservation measures are urgently required to reduce the severe black soil loss for sustainable management of the soil resource.

  8. Using Unmanned Aerial Vehicle (UAV) for spatio-temporal monitoring of soil erosion and roughness in Chania, Crete, Greece

    NASA Astrophysics Data System (ADS)

    Alexakis, Dimitrios; Seiradakis, Kostas; Tsanis, Ioannis

    2016-04-01

    This article presents a remote sensing approach for spatio-temporal monitoring of both soil erosion and roughness using an Unmanned Aerial Vehicle (UAV). Soil erosion by water is commonly known as one of the main reasons for land degradation. Gully erosion causes considerable soil loss and soil degradation. Furthermore, quantification of soil roughness (irregularities of the soil surface due to soil texture) is important and affects surface storage and infiltration. Soil roughness is one of the most susceptible to variation in time and space characteristics and depends on different parameters such as cultivation practices and soil aggregation. A UAV equipped with a digital camera was employed to monitor soil in terms of erosion and roughness in two different study areas in Chania, Crete, Greece. The UAV followed predicted flight paths computed by the relevant flight planning software. The photogrammetric image processing enabled the development of sophisticated Digital Terrain Models (DTMs) and ortho-image mosaics with very high resolution on a sub-decimeter level. The DTMs were developed using photogrammetric processing of more than 500 images acquired with the UAV from different heights above the ground level. As the geomorphic formations can be observed from above using UAVs, shadowing effects do not generally occur and the generated point clouds have very homogeneous and high point densities. The DTMs generated from UAV were compared in terms of vertical absolute accuracies with a Global Navigation Satellite System (GNSS) survey. The developed data products were used for quantifying gully erosion and soil roughness in 3D as well as for the analysis of the surrounding areas. The significant elevation changes from multi-temporal UAV elevation data were used for estimating diachronically soil loss and sediment delivery without installing sediment traps. Concerning roughness, statistical indicators of surface elevation point measurements were estimated and various

  9. East African Soil Erosion Recorded in a 300 Year old Coral Colony From Kenya

    NASA Astrophysics Data System (ADS)

    Dunbar, R. B.; Fleitmann, D.; McCulloch, M.; Mudelsee, M.; Vuille, M.; McClanahan, T.; Cole, J.; Eggins, S.

    2006-12-01

    Soil erosion threatens the food security of 2.6 billion people worldwide. The situation is particularly dire in East and Sub-Saharan Africa where per capita food production has declined over the past 45 years. Erosion and the resultant loss of fertile soil is a key socio-economic and ecological problem in Kenya, affecting all sectors of its economy and damaging marine and terrestrial ecosystems. The temporal pattern of soil erosion is almost unknown and currently only sparse and rather anecdotal information exists. To aid in filling this gap of knowledge, we present a 300-year long Barium record from two Kenyan coral colonies (Porites sp., 3°15'S, 40°9' E; Malindi Marine National Park) that documents a dynamic history of soil erosion in the Sabaki river drainage basin. To reconstruct Sabaki River sediment flux to the Malindi coral reef Ba/Ca ratios were measured in the skeleton of two Porites colonies (Mal 96-1 and Mal 95-3). Well-developed annual bands allow us to develop annually precise chronologies. Ba/Ca ratios were measured in core Mal 96-1 at continuous 40 μm intervals (~400 to 500 samples yr-1) using laser-ablation inductively coupled plasma mass spectrometry (LA- ICP-MS). To test for reproducibility and accuracy of the Mal 96-1 Ba/Ca profile, coral core Mal 95-3 was analyzed at lower resolution (1 to 12 samples yr-1) using discrete micro-drill sampling and isotope dilution ICP-MS. The close similarity between both coral Ba/Ca profiles, in absolute values as well as general pattern, underscores the accuracy of the LA-ICP-MS technique and adds confidence to our interpretation of the 300 year long Mal 96-1 Ba/Ca profile. The Ba/Ca coral proxy record shows that while the sediment flux from the Sabaki River is nearly constant between 1700 and 1900, a continuous rise in sediment flux is observed since 1900, reflecting steadily increasing demographic pressure on land use. The peak in suspended sediment load and hence soil erosion recorded at the Malindi reef

  10. Soil Erosion in agro-industrially used Landscapes between High and Anti-Atlas

    NASA Astrophysics Data System (ADS)

    Peter, K. D.; Ries, J. B.; Marzolff, I.; d'Oleire-Oltmanns, S.

    2012-04-01

    The Souss basin is characterised by high population dynamics and changing land use. Extensive plantations of citrus fruits, bananas and vegetables in monocropping, mainly for the European market, replace the traditional mixed agriculture with small-area olive orchards and cereal fields. A precipitation of around 200 mm enforces the irrigation of cultivation by deep wells. The spatial vicinity of highly engineered irrigation areas, which are often created by land-levelling measures, and housing estates with highly active gully systems and rapid badland development presents a risk to both the agro-industrial land use and the population settlements. It is investigated whether the levelling measures influence surface runoff and soil erosion and thereby affect the further gully development. The influences of surface characteristics on runoff and soil erosion are analysed. Therefore 91 rainfall simulation experiments using a small portable rainfall simulator and 33 infiltrations by means of a single ring infiltrometer are carried out on seven test sites nearby the city of Taroudant. The rainfall simulations (30 minutes, 40 mm h-1) show an average runoff coefficient of between 54 and 59 % on test sites with land-levelling measures and average runoff coefficients ranging between 36 and 48 % on mostly non-levelled test sites. The average of soil erosion lies on levelled test sites between 52.1 and 81.8 g m-2, on non-levelled test-sites between 13.2 und 23.2 g m-2 per 30 minutes. Accordingly, all the test sites have a rather low infiltration capacity. This can also be confirmed by the low average infiltration depth of only 15.5 cm on levelled test sites. There is often a clear borderline at horizons with a high bulk density caused by compaction. In contrast, on non-levelled test sites, the average infiltration depth reaches 22.2 cm. Reinforcing factors for runoff and soil erosion are slope and soil crusts. Vegetation cover has a reducing influence on surface process activity

  11. Fallow Effects on Improving Soil Properties and Decreasing Erosion: Atlantic Forest, Southeastern Brazil

    NASA Astrophysics Data System (ADS)

    Miranda, J. P.; Silva, L. M.; Lima, R. L.; Donagemma, G. K.; Bertolino, A. V. A.; Fernandes, N. F.; Correa, F. M.; Polidoro, J. C.; Tato, G.

    2009-04-01

    fallow) and forest. For each case, 12 soil samples were collected at 4 depths: 0-5, 5-10, 10-20 and 20-30cm, with 3 repetitions, leading to a total of 60 soil samples, where the following properties were characterized: porosity (micro, macro and total), bulk density and aggregate stability. Besides, in situ measurements of saturated hydraulic conductivity were conducted with a Guelph permeameter. The results obtained in this study attested that all the soil properties analyzed were affected by soil usage, especially at shallow depths, in particular macroporosity and total porosity, which have major influences on infiltration rates, runoff and soil erosion. Besides, the results suggested that the 5-year fallow (F5) was able to recover from 72% to 100% of total porosity for the 0-10cm depth layer (considering forest values as reference), while in the 2-year fallow (F2) this recovery was lower, ranging from 66 to 80%. A similar trend was observed for macroporosity, showing recovering values from 60% to 90% and from 50% to 76%, for F5 and F2, respectively. However, aggregate stability values did not show significant variations between the two fallows. Saturated hydraulic conductivity, on the other hand, presented the lowest recovering values for all the studied properties: between 13% and 58% for F5 and between 6% and 33% for F2. Comparing to the natural forest (reference value), the coffee plantations presented the worst soil conditions in terms of soil hydrology and erosion. The results presented here attested important improvements in soil physical and hydrological properties after a 5-year fallow, leading to decrease in surface runoff and soil erosion in the area.

  12. The interaction between soil erosion and soil organisms in temperate agroecosystems: nematode redistribution in tramlines

    NASA Astrophysics Data System (ADS)

    Baxter, Craig; Rowan, John S.; McKenzie, Blair M.; Neilson, Roy

    2014-05-01

    Arable agriculture presents a unique set of challenges, and one of the most important is soil erosion. Whilst policy and practice look towards sustainable intensification of production to ensure food security, fundamental gaps in our understanding still exist. The physical processes involved in the detachment, transport and deposition of soil are well characterised but further research considering chemical and nutrient transport, fertiliser and pesticide losses, and environmental impacts to downstream environments is still required. Furthermore the interaction between soil erosion and soil organisms have largely been ignored, even though soil organisms serve a myriad of functions essential in the provision of soil ecosystem goods and services. Here we present the findings of a field-scale experiment into soil biotic redistribution undertaken at the James Hutton Institute's Balruddery Farm, Scotland (Link Tramlines Project XDW8001). Farm vehicle-tyre wheelings left in arable fields (tramlines) to enable crop spraying during the crop growth cycle have been identified as key transport pathways for sediment and associated nutrients. We tested the hypothesis that soil organisms were also transported by tramline erosion. During the winter of 2012/13 an experiment was undertaken to measure soil organism export from unbound hillslope plots subject to four different tramline treatments set out in a randomised block design. We used soil nematodes as a model organism as they are ubiquitous and sensitive to disturbance and an established indicator taxa of biological and physico-chemical changes in soil. Tramline treatments included a control tyre (conventional tractor tyre), a control tyre with a sown tramline, a low pressure tyre with sown tramline, and a control tyre with a spiked harrow. Post-event sampling of rainfall events was undertaken, and a range of variables measured in the laboratory. The spiked harrow treatment produced the greatest overall reductions in nematode

  13. High natural erosion rates are the backdrop for enhanced anthropogenic soil erosion in the Middle Hills of Nepal

    NASA Astrophysics Data System (ADS)

    West, A. J.; Arnold, M.; Aumaître, G.; Bourlès, D. L.; Keddadouche, K.; Bickle, M.; Ojha, T.

    2014-08-01

    Although agriculturally accelerated soil erosion is implicated in the unsustainable environmental degradation of mountain environments, such as in the Himalaya, the effects of land use can be difficult to quantify in many mountain settings because of the high and variable natural background rates of erosion. In this study, we present new long-term denudation rates, derived from cosmogenic 10Be analysis of quartz in river sediment from the Likhu Khola, a small agricultural river basin in the Middle Hills of central Nepal. Calculated long-term denudation rates, which reflect background natural erosion processes over 1000+ years prior to agricultural intensification, are similar to present-day sediment yields and to soil loss rates from terraces that are well-maintained. Similarity in short- and long-term catchment-wide erosion rates for the Likhu is consistent with data from elsewhere in the Nepal Middle Hills, but contrasts with the very large increases in short-term erosion rates seen in agricultural catchments in other steep mountain settings. Our results suggest that the large sediment fluxes exported from the Likhu and other Middle Hills rivers in the Himalaya are derived in large part from natural processes, rather than from soil erosion as a result of agricultural activity. Because of the high natural background rates, simple comparison of short- and long-term rates may not reveal unsustainable soil degradation, particularly if much of the catchment-scale erosion flux derives from mass wasting. Correcting for the mass wasting contribution in the Likhu implies minimum catchment-averaged soil production rates of ~0.25-0.35 mm yr-1. The deficit between these production rates and soil losses suggests that terraced agriculture in the Likhu may not be associated with a large systematic soil deficit, at least when terraces are well maintained, but that poorly managed terraces, forest and scrubland may lead to rapid depletion of soil resources.

  14. Morphometry and land cover based multi-criteria analysis for assessing the soil erosion susceptibility of the western Himalayan watershed.

    PubMed

    Altaf, Sadaff; Meraj, Gowhar; Romshoo, Shakil Ahmad

    2014-12-01

    Complex mountainous environments such as Himalayas are highly susceptibility to natural hazards particular those that are triggered by the action of water such as floods, soil erosion, mass movements and siltation of the hydro-electric power dams. Among all the natural hazards, soil erosion is the most implicit and the devastating hazard affecting the life and property of the millions of people living in these regions. Hence to review and devise strategies to reduce the adverse impacts of soil erosion is of utmost importance to the planners of watershed management programs in these regions. This paper demonstrates the use of satellite based remote sensing data coupled with the observational field data in a multi-criteria analytical (MCA) framework to estimate the soil erosion susceptibility of the sub-watersheds of the Rembiara basin falling in the western Himalaya, using geographical information system (GIS). In this paper, watershed morphometry and land cover are used as an inputs to the MCA framework to prioritize the sub-watersheds of this basin on the basis of their different susceptibilities to soil erosion. Methodology included the derivation of a set of drainage and land cover parameters that act as the indicators of erosion susceptibility. Further the output from the MCA resulted in the categorization of the sub-watersheds into low, medium, high and very high erosion susceptibility classes. A detailed prioritization map for the susceptible sub-watersheds based on the combined role of land cover and morphometry is finally presented. Besides, maps identifying the susceptible sub-watersheds based on morphometry and land cover only are also presented. The results of this study are part of the watershed management program in the study area and are directed to instigate appropriate measures to alleviate the soil erosion in the study area. PMID:25154685

  15. Runoff and interrill erosion in sodic soils treated with dry PAM and phosphogypsum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seal formation at the soil surface during rainstorms reduces rain infiltration and leads to runoff and erosion. An increase in soil sodicity increases soil susceptibility to crusting, runoff, and erosion. Surface application of dissolved polyacrylamide (PAM) mixed with gypsum was found to be very ef...

  16. Wind erosion induced soil degradation in Northern China: Status, measures and perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Soil degradation is one of the most serious ecological problems in the world. In arid and semi-arid northern China, soil degradation predominantly arises from wind erosion. Trends in soil degradation caused by wind erosion in northern China frequently change with human activities and climatic chan...

  17. Soil erosion: 20th century equations with 21st century data?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dust Bowl of the 1930's focused the attention of the US on soil erosion and land conservation. The Universal Soil Loss Equation (USLE) was the result of this effort and has remained one of the most widely used equations for soil erosion prediction world-wide. This empirical relationship has been...

  18. The contribution of mulches to control high soil erosion rates in vineyards in Eastern Spain

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Jordán, Antonio; Zavala, Lorena; José Marqués, María; Novara, Agata

    2014-05-01

    Soil erosion take place in degraded ecosystem where the lack of vegetation, drought, erodible parent material and deforestation take place (Borelli et al., 2013; Haregeweyn et al., 2013; Zhao et al., 2013). Agriculture management developed new landscapes (Ore and Bruins, 2012) and use to trigger non-sustainable soil erosion rates (Zema et al., 2012). High erosion rates were measured in agriculture land (Cerdà et al., 2009), but it is also possible to develop managements that will control the soil and water losses, such as organic amendments (Marqués et al., 2005), plant cover (Marqués et al., 2007) and geotextiles (Giménez Morera et al., 2010). The most successful management to restore the structural stability and the biological activity of the agriculture soil has been the organic mulches (García Orenes et al; 2009; 2010; 2012). The straw mulch is also very successful on bare fire affected soil (Robichaud et al., 2013a; 2013b), which also contributes to a more stable soil moisture content (García-Moreno et al., 2013). The objective of this research is to determine the impact of two mulches: wheat straw and chipped branches, on the soil erosion rates in a rainfed vineyard in Eastern Spain. The research site is located in the Les Alcusses Valley within the Moixent municipality. The Mean annual temperature is 13 ºC, and the mean annual rainfall 455 mm. Soil are sandy loam, and are developed at the foot-slope of a Cretaceous limestone range, the Serra Grossa range. The soils use to be ploughed and the features of soil erosion are found after each thunderstorm. Rills are removed by ploughing. Thirty rainfall simulation experiments were carried out in summer 2011 during the summer drought period. The simulated rainfall lasted during 1 hour at a 45 mmh-1 intensity on 1 m2 plots (Cerdà and Doerr, 2010; Cerdà and Jurgensen 2011). Ten experiments were carried out on the control plots (ploughed), 10 on straw mulch covered plots, and 10 on chipped branches covered

  19. Estimation Model of Soil Freeze-Thaw Erosion in Silingco Watershed Wetland of Northern Tibet

    PubMed Central

    2013-01-01

    The freeze-thaw (FT) erosion is a type of soil erosion like water erosion and wind erosion. Limited by many factors, the grading evaluation of soil FT erosion quantities is not well studied. Based on the comprehensive analysis of the evaluation indices of soil FT erosion, we for the first time utilized the sensitivity of microwave remote sensing technology to soil moisture for identification of FT state. We established an estimation model suitable to evaluate the soil FT erosion quantity in Silingco watershed wetland of Northern Tibet using weighted summation method of six impact factors including the annual FT cycle days, average diurnal FT phase-changed water content, average annual precipitation, slope, aspect, and vegetation coverage. Finally, with the support of GIS, we classified soil FT erosion quantity in Silingco watershed wetland. The results showed that soil FT erosion are distributed in broad areas of Silingco watershed wetland. Different soil FT erosions with different intensities have evidently different spatial and geographical distributions. PMID:23935427

  20. Estimation model of soil freeze-thaw erosion in Silingco watershed wetland of Northern Tibet.

    PubMed

    Kong, Bo; Yu, Huan

    2013-01-01

    The freeze-thaw (FT) erosion is a type of soil erosion like water erosion and wind erosion. Limited by many factors, the grading evaluation of soil FT erosion quantities is not well studied. Based on the comprehensive analysis of the evaluation indices of soil FT erosion, we for the first time utilized the sensitivity of microwave remote sensing technology to soil moisture for identification of FT state. We established an estimation model suitable to evaluate the soil FT erosion quantity in Silingco watershed wetland of Northern Tibet using weighted summation method of six impact factors including the annual FT cycle days, average diurnal FT phase-changed water content, average annual precipitation, slope, aspect, and vegetation coverage. Finally, with the support of GIS, we classified soil FT erosion quantity in Silingco watershed wetland. The results showed that soil FT erosion are distributed in broad areas of Silingco watershed wetland. Different soil FT erosions with different intensities have evidently different spatial and geographical distributions. PMID:23935427

  1. Applying transport-distance specific SOC distribution to calibrate soil erosion model WaTEM

    NASA Astrophysics Data System (ADS)

    Hu, Yaxian; Heckrath, Goswin J.; Kuhn, Nikolaus J.

    2016-04-01

    Slope-scale soil erosion, transport and deposition fundamentally decide the spatial redistribution of eroded sediments in terrestrial and aquatic systems, which further affect the burial and decomposition of eroded SOC. However, comparisons of SOC contents between upper eroding slope and lower depositional site cannot fully reflect the movement of eroded SOC in-transit along hillslopes. The actual transport distance of eroded SOC is decided by its settling velocity. So far, the settling velocity distribution of eroded SOC is mostly calculated from mineral particle specific SOC distribution. Yet, soil is mostly eroded in form of aggregates, and the movement of aggregates differs significantly from individual mineral particles. This urges a SOC erodibility parameter based on actual transport distance distribution of eroded fractions to better calibrate soil erosion models. Previous field investigation on a freshly seeded cropland in Denmark has shown immediate deposition of fast settling soil fractions and the associated SOC at footslopes, followed by a fining trend at the slope tail. To further quantify the long-term effects of topography on erosional redistribution of eroded SOC, the actual transport-distance specific SOC distribution observed on the field was applied to a soil erosion model WaTEM (based on USLE). After integrating with local DEM, our calibrated model succeeded in locating the hotspots of enrichment/depletion of eroded SOC on different topographic positions, much better corresponding to the real-world field observation. By extrapolating into repeated erosion events, our projected results on the spatial distribution of eroded SOC are also adequately consistent with the SOC properties in the consecutive sample profiles along the slope.

  2. Revisiting classic water erosion models in drylands: The strong impact of biological soil crusts

    USGS Publications Warehouse

    Bowker, M.A.; Belnap, J.; Bala, Chaudhary V.; Johnson, N.C.

    2008-01-01

    Soil erosion and subsequent degradation has been a contributor to societal collapse in the past and is one of the major expressions of desertification in arid regions. The revised universal soil loss equation (RUSLE) models soil lost to water erosion as a function of climate erosivity (the degree to which rainfall can result in erosion), topography, soil erodibility, and land use/management. The soil erodibility factor (K) is primarily based upon inherent soil properties (those which change slowly or not at all) such as soil texture and organic matter content, while the cover/management factor (C) is based on several parameters including biological soil crust (BSC) cover. We examined the effect of two more precise indicators of BSC development, chlorophyll a and exopolysaccharides (EPS), upon soil stability, which is closely inversely related to soil loss in an erosion event. To examine the relative influence of these elements of the C factor to the K factor, we conducted our investigation across eight strongly differing soils in the 0.8 million ha Grand Staircase-Escalante National Monument. We found that within every soil group, chlorophyll a was a moderate to excellent predictor of soil stability (R2 = 0.21-0.75), and consistently better than EPS. Using a simple structural equation model, we explained over half of the variance in soil stability and determined that the direct effect of chlorophyll a was 3?? more important than soil group in determining soil stability. Our results suggest that, holding the intensity of erosive forces constant, the acceleration or reduction of soil erosion in arid landscapes will primarily be an outcome of management practices. This is because the factor which is most influential to soil erosion, BSC development, is also among the most manageable, implying that water erosion in drylands has a solution. ?? 2008 Elsevier Ltd.

  3. The impact of soil preparation on the soil erosion rates under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Khaledi Darvishan, A.; Homayounfar, V.; Sadeghi, S. H. R.

    2015-03-01

    The use of laboratory methods in soil erosion studies causes soil disturbance, preparation and placement in experimental plots and has been recently considered more and more because of many advantages. However, different stages of soil removal, transfer, preparation and placement in laboratory plots cause significant changes in soil structure and subsequently, the results of runoff, sediment concentration and soil loss. Knowing the rate of changes in sediment concentration and soil loss variables with respect to the soil preparation for laboratory studies is therefore inevitable to generalize the laboratory results to field conditions. However, there has been less attention to evaluate the effects of soil preparation on sediment variables. The present study was therefore conducted to compare sediment concentration and soil loss in natural and prepared soil. To achieve the study purposes, 18 field 1 m × 1 m-plots were adopted in an 18% gradient slope with sandy-clay-loam soil in the Kojour watershed, Northern Iran. Three rainfall intensities of 40, 60 and 80 mm h-1 were simulated on both prepared and natural soil treatments with three replications. The sediment concentration and soil loss at five three-minute intervals after time-to-runoff were then measured. The results showed the significant (p ≤ 0.01) increasing effects of soil preparation on the average sediment concentration and soil loss. The increasing rates of runoff coefficient, sediment concentration and soil loss due to the study soil preparation method for laboratory soil erosion plots, were 179, 183 and 1050% (2.79, 2.83 and 11.50 times), respectively.

  4. Remote sensing and spatially distributed erosion models as a tool to really understand biocrust effects on soil erosion

    NASA Astrophysics Data System (ADS)

    Rodriguez-Caballero, Emilio; Chamizo, Sonia; Román, Raul; Roncero, Beatriz; Weber, Bettina; Jetten, Victor; Cantón, Yolanda

    2016-04-01

    Since publication of the first Ecological Stides volume on biological soil crusts (biocrusts) in 2003, numerous studies have been conducted trying to understand the role of biocrusts in runoff generation and water erosion. Most of them considered these communities as one of the most important stabilizing factors dryland regions. However, these studies were concentrated only on patch or hillslope scales, and there is a lack of information on biocrust interactions with other surface components at catchment scale. Even on fine textured soils, where biocrusts increase water infiltration, they act as runoff source when compared to vegetation. Run-on from biocrusted areas may be harvested by downslope vegetation, but sometimes it may promote downslope erosion. Thus, to really understand the effect of biocrusts on soil erosion, studies on larger scales, preferably on a catchment scale are needed. For this we developed a new approach, based on field measurements and remote sensing techniques, to include biocrust effects in physically-based runoff and erosion modeling. Doing this we were able to analyze how runoff generated in biocrust areas is redistributed within the landscape and its effect on catchment water erosion. The Limburg Soil Erosion Model (LISEM) was used to parameterize and simulate the effects of biocrusts on soil erosion in a small badlands catchment, where biocrusts represent one of the main surface components. Biocrust stability and cohesion were measured in the field, their hydrological properties were obtained from runoff plots, and their cover and spatial distribution was estimated from a hyperspectral image by linear mixture analysis. Then, the model was run under different rainfall intensities and final runoff and erosion rates were compared with field data measured at the catchment outlet. Moreover, these results were compared with the hypothetical scenario in which biocrusts were removed, simulating human disturbances or climatic change effects on

  5. Effects of land clearing techniques and tillage systems on runoff and soil erosion in a tropical rain forest in Nigeria.

    PubMed

    Ehigiator, O A; Anyata, B U

    2011-11-01

    This work reports runoff and soil loss from each of 14 sub-watersheds in a secondary rain forest in south-western Nigeria. The impact of methods of land clearing and post-clearing management on runoff and soil erosion under the secondary forest is evaluated. These data were acquired eighteen years after the deforestation of primary vegetation during the ' West bank' project of the International Institute for Tropical Agriculture (IITA). These data are presented separately for each season; however, statistical analyses for replicates were not conducted due to differences in their past management. Soil erosion was affected by land clearing and tillage methods. The maximum soil erosion was observed on sub-watersheds that were mechanically cleared with tree-pusher/root-rake attachments and tilled conventionally. A high rate of erosion was observed even when graded-channel terraces were constructed to minimize soil erosion. In general there was much less soil erosion on manually cleared than on mechanically cleared sub-watersheds (2.5 t ha(-1) yr(-1) versus 13.8 t ha(-1) yr(-1)) and from the application of no-tillage methods than from conventionally plowed areas (6.5 t ha(-1) yr(-1) versus 12.1 t ha(-1) yr(-1)). The data indicate that tillage methods and appropriate management of soils and crops play an important role in soil and water conservation and in decreasing the rate of decline of soil quality. PMID:21783317

  6. Soil erosion and sediment control laws. A review of state laws and their natural resource data requirements

    NASA Technical Reports Server (NTRS)

    Klein, S. B.

    1980-01-01

    Twenty states, the District of Columbia, and the Virgin Islands enacted erosion and sediment control legislation during the past decade to provide for the implementation or the strengthening of statewide erosion and sediment control plans for rural and/or urban lands. That legislation and the state programs developed to implement these laws are quoted and reviewed. The natural resource data requirements of each program are also extracted. The legislation includes amendments to conservation district laws, water quality laws, and erosion and sediment control laws. Laws which provides for legislative review of administrative regulations and LANDSAT applications and/or information systems that were involved in implementing or gathering data for a specific soil erosion and sediment control program are summarized as well as principal concerns affecting erosion and sediment control laws.

  7. Role of the Duff Layer in Post-fire Soil Hydrology and Erosion: Field and Modelling Observations

    NASA Astrophysics Data System (ADS)

    Martin, Y. E.; Johnson, E. A.; Gallaway, J.

    2010-12-01

    is not the case for all ecosystems. For example, earlier research in the boreal forest of Canada has shown that duff consumption during high-intensity crown fires results in patchy yet notable post-fire duff coverage, similar to the post-fire duff coverage found at our field site. To assess how the duff layer might affect soil hydrology in post-fire environments, we undertake a numerical modelling exercise. Model runs are undertaken for a series of different soil types (sandy loam etc.), some with an overlying duff layer and some without an overlying duff layer. Model results suggest that the presence of a duff layer does affect the soil infiltration process and the time required for ponding to occur. It is recommended that researchers and land managers consider the extent of post-fire duff coverage in different regional settings to allow for better assessment of the potential for notable, post-fire soil erosion.

  8. How two single events control the erosion process on citrus orchards in the Montesa soil erosion research station

    NASA Astrophysics Data System (ADS)

    Cerdà, A.; Giménez-Morera, A.; Domínguez-Gento, A.

    2010-05-01

    Single events control the soil erosion processes on Mediterranean type ecosystems. They contribute with the largest soil and water losses. A five year research carried out on the soil erosion experimental station of Montesa, eastern Spain demonstrates that the soil erosion by water is mainly concentrated on high intensity (> 100 mm day-1) thunderstorms. Six plots (300 m2) were built in 2003 to collect runoff and sediments after each rainfall event. The measurements show that 91.34 % of the total soil loss and the 76.32 % of the runoff collected from 2004 to 2008 was collected during two rainfall events that surpassed 160 mm day-1. The six plots were under organic farming strategies and then the soil losses were always lower than 1 Mg ha-1 year-1. Under dense vegetation cover found on organic farming orchards the soil erosion process is concentrated on short periods of time. In fact, two days of rainfall contributed with 9-times more runoff and soil losses than the 345 days of rainfall during the 5 year times of the study.

  9. Investigation of Soil Erosion and Phosphorus Transport within an Agricultural Watershed

    NASA Astrophysics Data System (ADS)

    Klik, A.; Jester, W.; Muhar, A.; Peinsitt, A.; Rampazzo, N.; Mentler, A.; Staudinger, B.; Eder, M.

    2003-04-01

    In a 40 ha agricultural used watershed in Austria, surface runoff, soil erosion and nutrient losses are measured spatially distributed with 12 small erosion plots. Crops during growing season 2002 are canola, corn, sunflower, winter wheat, winter barley, rye, sugar beets, and pasture. Canopy height and canopy cover are observed in 14-day intervals. Four times per year soil water content, shear stress and random roughness of the surface are measured in a 25 x 25 m grid (140 points). The same raster is sampled for soil texture analyses and content of different phosphorus fractions in the 0-10 cm soil depth. Spatially distributed data are used for geostatistical analysis. Along three transects hydrologic conditions of the hillslope position (top, middle, foot) are investigated by measuring soil water content and soil matrix potential. After erosive events erosion features (rills, deposition, ...) are mapped using GPS. All measured data will be used as input parameters for the Limburg Soil Erosion Model (LISEM).

  10. Effect of soil erosion on dissolved organic carbon redistribution in subtropical red soil under rainfall simulation

    NASA Astrophysics Data System (ADS)

    Ma, Wenming; Li, Zhongwu; Ding, Keyi; Huang, Jinquan; Nie, Xiaodong; Zeng, Guangming; Wang, Shuguang; Liu, Guiping

    2014-12-01

    Water erosion governs soil carbon reserves and distribution across the watershed or ecosystem. The dynamics of dissolved organic carbon (DOC) under water erosion in red agricultural soil is not clear. To determine the effect of tillage management and water erosion on vertical and lateral transportation of soil organic carbon (SOC) and DOC production under distinct rainfall intensities in the hilly red soil region of southern China, a chisel tillage plot with low rainfall intensity (CT-L) and two no-tillage plots with high (NT-H) and low rainfall intensity (NT-L) studies were conducted. Soil samples were collected from 0-5, 5-10, 10-20, and 20-40 cm soil layers from triplicate soil blocks pre- and post-rainfall for determining concentration of SOC and DOC. Runoff samples were collected at every 6 min for determining concentration of DOC and sediments during rainfall simulations on runoff plots (2 m × 5 m) with various intensities. No fertilizer was applied in any plots. Results clearly show that runoff volumes, sediments and SOC entrained with sediment, and laterally mobilized DOC were significantly larger on NT-H compared to other plots, coinciding with changes in rainfall intensity; and the extent of roughness of the plot surface (CT vs. NT) was the variation in runoff DOC concentration. During the simulated rainfall events, DOC exports average 0.76, 0.64, and 0.27 g C m- 2 h- 1; SOC exports average 3.52, 1.08, and 0.07 g m- 2 h- 1 in the NT-H, NT-L, and CT-L soils, respectively. The maximum export of DOC was obtained under a high intensity rainfall plot, which lagged behind maximum runoff volumes, sediments, and SOC losses with sediment. Export of DOC was proportional to SOC content of soil loss. The least DOC losses in surface runoff and SOC losses with sediment were observed in CT-L plots. Vertical DOC mobilization achieved its maximum with low intensity rainfall under CT treatment. The DOC did not accumulate at the soil surface and was distributed mainly in

  11. [Using 137Cs and 210Pb(ex) to trace the impact of soil erosion on soil organic carbon at a slope farmland in the black soil region].

    PubMed

    Fang, Hai-Yan; Sheng, Mei-Ling; Sun, Li-Ying; Cai, Qiang-Guo

    2013-07-01

    Soil cores were collected from a 28.5 hm2 slope farmland in the black soil region of Northeast China. Based on the sampled data of 137Cs, 210Pb(ex) and SOC, the potentials of applying 137Cs and 210Pb(ex) for assessing SOC redistribution were evaluated, aimed to approach the impact of soil erosion on soil organic carbon (SOC) in black soil region. At both planar and vertical directions, the 137Cs, 210Pb(ex) and SOC in the farmland had similar distribution patterns. Although there were large planar variations in the 137Cs and 210Pb(ex) areal activities and the SOC stock as affected by soil erosion and deposition, the 137Cs, 210Pb(ex) and SOC had similar changing trends over the landscape. Two depth distribution profiles were also used to study the relations of 137Cs and 210Pb(ex) with SOC. At eroded site, the radioactivities of 137Cs and 210Pb(ex) and the SOC mass fraction did not show large variations in 0-25 cm soil layer, but decreased sharply below 25 cm. For the deposition sample, the radioactivities of 137Cs and 210Pb(ex) in 0-100 cm soil increased firstly and then decreased. The SOC mass fraction also had similar depth distribution pattern in this soil layer. The 137Cs and 210Pb(ex) presented positive linear correlations with the SOC, indicating that 137Cs, 210Pb(ex) and SOC moved with the same physical mechanism in the farmland, and fallout 137Cs and 210Pb(ex) could be used to study spatio-temporal distribution characteristics of SOC in the black soil region under the condition of soil erosion. PMID:24175514

  12. Assessment of soil erosion sensitivity and post-timber-harvesting erosion response in a mountain environment of Central Italy

    NASA Astrophysics Data System (ADS)

    Borrelli, Pasquale; Schütt, Brigitta

    2014-01-01

    This study aimed to assess the effects of forest management on the occurrence of accelerated soil erosion by water. The study site is located in a mountainous area of the Italian Central Apennines. Here, forest harvesting is a widespread forestry activity and is mainly performed on the moderate to steep slopes of the highlands. Through modeling operations based on data on soil properties and direct monitoring of changes in the post-forest-harvesting soil surface level at the hillslope scale, we show that the observed site became prone to soil erosion after human intervention. Indeed, the measured mean soil erosion rate of 49 t ha- 1 yr- 1 for the harvested watershed is about 21 times higher than the rate measured in its neighboring undisturbed forested watershed (2.3 t ha- 1 yr- 1). The erosive response is greatly aggravated by exposing the just-harvested forest, with very limited herbaceous plant cover, to the aggressive attack of the heaviest annual rainfall without adopting any conservation practices. The erosivity of the storms during the first four months of field measurements was 1571 MJ mm h- 1 ha- 1 in total (i.e., from September to December 2008). At the end of the experiment (16 months), 18.8%, 26.1% and 55.1% of the erosion monitoring sites in the harvested watershed recorded variations equal or greater than 0-5, 5-10 and > 10 mm, respectively. This study also provides a quantification of Italian forestland surfaces with the same pedo-lithological characteristics exploited for wood supply. Within a period of ten years (2002-2011), about 9891 ha of coppice forest changes were identified and their potential soil erosion rates modeled.

  13. Detection of soil erosion within pinyon-juniper woodlands using Thematic Mapper (TM) data

    NASA Technical Reports Server (NTRS)

    Price, Kevin P.

    1993-01-01

    Multispectral measurements collected by Landsat Thematic Mapper (TM) were correlated with field measurements, direct soil loss estimates, and Universal Soil Loss Equation (USLE) estimates to determine the sensitivity of TM data to varying degrees of soil erosion in pinyon-juniper woodland in central Utah. TM data were also evaluated as a predictor of the USLE Crop Management C factor for pinyon-juniper woodlands. TM spectral data were consistently better predictors of soil erosion factors than any combination of field factors. TM data were more sensitive to vegetation variations than the USLE C factor. USLE estimates showed low annual rates of erosion which varied little among the study sites. Direct measurements of rate of soil loss using the SEDIMENT (Soil Erosion DIrect measureMENT) technique, indicated high and varying rates of soil loss among the sites since tree establishment. Erosion estimates from the USLE and SEDIMENT methods suggest that erosion rates have been severe in the past, but because significant amounts of soil have already been eroded, and the surface is now armored by rock debris, present erosion rates are lower. Indicators of accelerated erosion were still present on all sites, however, suggesting that the USLE underestimated erosion within the study area.

  14. Antecedent moisture content and soil texture effects on infiltration and erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water infiltration, seal formation, runoff and erosion depend on the soil’s inherent properties and surface conditions. Most erosion models consider only soil inherent properties (mainly texture) in assessing infiltration and erosion without consideration of spatial and temporary variation in the su...

  15. Coupled dynamics of soil formation and erosion in natural and agricultural ecosystems

    NASA Astrophysics Data System (ADS)

    Pelak, N. F.; Manzoni, S.; Wang, J.; Bras, R. L.; Porporato, A. M.

    2013-12-01

    Soil development by weathering is counterbalanced by losses through erosion. This balance may be disturbed by extreme natural events and human activities, resulting in reduced soil depths, deteriorated soil hydraulic properties, and loss of biogeochemical function. The presence of vegetation, while accelerating soil development is also necessary to maintain soil stability by reducing erosion. Plants require in turn a hydrologically and biogeochemically suitable soil environment to thrive. It is thus conceivable that disturbed soil states may allow lower vegetation carrying capacity, leading to increased erosion and further decline in vegetation and ecosystem function. Such disturbed systems may recover slowly or not at all. We explore these positive feedbacks by employing a minimal model of coupled nonlinear differential equation for the dynamics of soil development, vegetation, and surface hydrology. The model describes a plant compartment, soil carbon, soil depth, and soil moisture, and includes key feedbacks such as plant-driven inhibition of erosion, dynamic changes in rooting depth and soil textural properties as erosion progresses, and vegetation water stress. Results suggest that ecosystem functioning may deteriorate under various climate scenarios that could cause both longer droughts and higher erosion rates. Impact of anthropogenic disturbances such as removal of vegetation and tillage on the mass and energy balances of the soil-plant system and the stability of the systems are also investigated using this modeling framework, with special attention to land use changes in the Southeastern US and soil degradation problems at the Calhoun Critical Zone Observatory (CZO).

  16. Erosion of upland hillslope soil organic carbon: Coupling field measurements with a sediment transport model

    NASA Astrophysics Data System (ADS)

    Yoo, Kyungsoo; Amundson, Ronald; Heimsath, Arjun M.; Dietrich, William E.

    2005-09-01

    Little is known about the role of vegetated hillslope sediment transport in the soil C cycle and soil-atmosphere C exchange. We combined a hillslope sediment transport model with empirical soil C measurements to quantify the erosion and temporal storage of soil organic carbon (SOC) within two grasslands in central California. The sites have contrasting erosional mechanisms: biological perturbation (Tennessee Valley (TV)) versus clay-rich soil creep (Black Diamond (BD)). The average SOC erosion rates from convex slopes were 1.4-2.7 g C m-2 yr-1 at TV and 5-8 g C m-2 yr-1 at BD, values that are <10% of above ground net primary productivity (ANPP) at both sites. The eroded soil accumulates on depositional slopes. The long term SOC accumulation (or C sink) rates are ˜1.9 g C m-2 yr-1 in the TV hollow and 1.7-2.8 g C m-2 yr-1 in the BD footslope. We found that the hillslope C sink is driven primarily by the burial of in situ plant production rather than preservation of eroded SOC, a finding that differs from existing hypotheses. At TV, the net sequestration of atmospheric C by long-term hollow evacuation and refilling depends on the fate of the C exported from the zero order watershed. This study suggests that erosion and deposition are coupled processes that create a previously unrecognized C sink in undisturbed upland watersheds, with a potential to substantially affect the global C balance presently, and over geological timescales.

  17. Mapping Erosion Risk in California's Rangelands Using the Universal Soil Loss Equation (USLE)

    NASA Astrophysics Data System (ADS)

    Salls, W. B.; O'Geen, T. T.

    2015-12-01

    Soil loss constitutes a multi-faceted problem for agriculture: in addition to reducing soil fertility and crop yield, it compromises downstream water quality. Sediment itself is a major issue for aquatic ecosystems, but also serves as a vector for transporting nutrients, pesticides, and pathogens. Rangelands are thought to be a contributor to water quality degradation in California, particularly in the northern Coast Range. Though total maximum daily loads (TMDLs) have been imposed in some watersheds, and countless rangeland water quality outreach activities have been conducted, the connection between grazing intensity recommendations and changes in water quality is poorly understood at the state level. This disconnect gives rise to poorly informed regulations and discourages adoption of best management practices by ranchers. By applying the Universal Soil Loss Equation (USLE) at a statewide scale, we highlighted areas most prone to erosion. We also investigated how two different grazing intensity scenarios affect modeled soil loss. Geospatial data layers representing the USLE parameters—rainfall erosivity, soil erodibility, slope length and steepness, and cover—were overlaid to model annual soil loss. Monitored suspended sediment data from a small North Coast watershed with grazing as the predominant land use was used to validate the model. Modeled soil loss values were nearly one order of magnitude higher than monitored values; average soil loss feeding the downstream-most site was modeled at 0.329 t ha-1 yr-1, whereas storm-derived sediment passing the site over two years was calculated to be 0.037 t ha-1 yr-1. This discrepancy may stem from the fact that the USLE models detached sediment, whereas stream monitoring reflects sediment detached and subsequently transported to the waterway. Preliminary findings from the statewide map support the concern that the North Coast is particularly at risk given its combination of intense rain, erodible soils, and

  18. Soil erosion rates by wind-driven rain from a sandy soil in Denmark

    NASA Astrophysics Data System (ADS)

    Fister, W.; Kuhn, N. J.; Itin, N.; Tesch, S.; Heckrath, G.; Ries, J. B.

    2012-04-01

    Soil erosion by wind and water is able to cause severe soil loss from agricultural fields. Laboratory studies in recent years have shown that wind most probably has an increasing effect on soil erosion rates by water. However, field studies have so far not been able to quantify and proof this assumption explicitly. Especially the differentiation between the influence of windless and wind-driven erosion seems to be the major issue. The objectives of this study were, therefore, to explicitly investigate the importance of wind-driven rain in relation to erosion rates without the effect of wind by applying a newly developed Portable Wind and Rainfall Simulator (PWRS) that is able to simulate the processes both separately and simultaneously. The PWRS was used on bare sandy soil near Viborg, Denmark. Prior to simulation the soil was ploughed and after consolidation harrowed to create surface structures and roughness representing typical conditions after seed bed preparation. To facilitate the separation of specific influences by wind-driven rain and to avoid systematic errors a defined order of four consecutive test runs was established: 0) single wind test run for 10 min, 1) single rainfall test run on dry soil, 2) single rainfall test run on moist soil, 3) simultaneous wind and rainfall test run (wind-driven rainfall). Each rainfall simulation lasted for 30 minutes with a 30 min break in between to allow for initial drainage of the soil and for remounting sediment catchers. By utilizing a gutter in combination with wedge-shaped sediment traps it was possible to separate between splash and runoff erosion from the 2.2 m2 plot. The results show a wide range of soil detachment raging from zero up to more than 500 g m-2 in 30 minutes. Five out of nine test sequences support the theory that wind-driven rain causes more erosion than windless rain. The relation between the two processes is therefore not as clear as expected and seems to be dominated by the natural variability

  19. Assessing soil erosion risk using RUSLE through a GIS open source desktop and web application.

    PubMed

    Duarte, L; Teodoro, A C; Gonçalves, J A; Soares, D; Cunha, M

    2016-06-01

    Soil erosion is a serious environmental problem. An estimation of the expected soil loss by water-caused erosion can be calculated considering the Revised Universal Soil Loss Equation (RUSLE). Geographical Information Systems (GIS) provide different tools to create categorical maps of soil erosion risk which help to study the risk assessment of soil loss. The objective of this study was to develop a GIS open source application (in QGIS), using the RUSLE methodology for estimating erosion rate at the watershed scale (desktop application) and provide the same application via web access (web application). The applications developed allow one to generate all the maps necessary to evaluate the soil erosion risk. Several libraries and algorithms from SEXTANTE were used to develop these applications. These applications were tested in Montalegre municipality (Portugal). The maps involved in RUSLE method-soil erosivity factor, soil erodibility factor, topographic factor, cover management factor, and support practices-were created. The estimated mean value of the soil loss obtained was 220 ton km(-2) year(-1) ranged from 0.27 to 1283 ton km(-2) year(-1). The results indicated that most of the study area (80 %) is characterized by very low soil erosion level (<321 ton km(-2) year(-1)) and in 4 % of the studied area the soil erosion was higher than 962 ton km(-2) year(-1). It was also concluded that areas with high slope values and bare soil are related with high level of erosion and the higher the P and C values, the higher the soil erosion percentage. The RUSLE web and the desktop application are freely available. PMID:27184749

  20. Surface Roughness Effects on Runoff and Soil Erosion Rates Under Simulated Rainfall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil surface roughness is identified as one of the controlling factors governing runoff and soil loss, yet, most studies pay little attention to soil surface roughness. In this study, we analyzed the influence of random soil surface roughness on runoff and soil erosion rates. Bulk samples of a silt ...

  1. Surface Roughness effects on Runoff and Soil Erosion Rates Under Simulated Rainfall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil surface roughness is identified as one of the controlling factors governing runoff and soil loss yet, most studies pay little attention to soil surface roughness. In this study, we analyzed the influence of random soil surface roughness on runoff and soil erosion rates. Bulk samples of a silt l...

  2. Soil erosion rates from mixed soil and gravel surfaces in a wind tunnel

    SciTech Connect

    Ligotke, M.W.; Klopfer, D.C.

    1990-08-01

    Protective barriers have been identified as integral components of plans to isolate defense waste on the Hanford Site. The use of natural materials to construct protective barriers over waste site is being considered. Design requirements for protective barriers include preventing exposure of buried waste, and restricting penetration or percolation of surface waters through the waste zone. Studies were initiated to evaluate the effects of wind erosion on candidate protective barrier surfaces. A wind tunnel was used to provide controlled erosive stresses and to investigate the erosive effects of wind forces on proposed surface layers for protective barriers. Mixed soil and gravel surfaces were prepared and tested for resistance to wind erosion at the Pacific Northwest Laboratory Aerosol Wind Tunnel Research Facility. These tests were performed to investigate surface deflation caused by suspension of soil from various surface layer configurations and to provide a comparison of the relative resistance of the different surfaces to wind erosion. Planning, testing, and analyzing phases of this wind erosion project were coordinated with other tasks supporting the development of protective barriers. These tasks include climate-change predictions, field studies and modeling efforts. This report provides results of measurements of deflation caused by wind forces over level surfaces. Section 2.0 reviews surface layer characteristics and previous relevant studies on wind erosion, describes effects of erosion, and discusses wind tunnel modeling. Materials and methods of the wind tunnel tests are discussed in Section 3.0. Results and discussion are presented in Section 4.0, and conclusions and recommendations Section 5.0. 53 refs., 29 figs., 7 tabs.

  3. Mapping of monthly soil erosion risk of mainland Mauritius and its aggregation with delineated basins

    NASA Astrophysics Data System (ADS)

    Nigel, Rody; Rughooputh, Soonil

    2010-01-01

    This paper reports the mapping of monthly soil erosion risk on Mauritius which was carried out using GIS, decision rules and readily available data namely, monthly rainfall depth, soil types, slope and land cover. Slope and soil were first combined to produce soil erosion susceptibility followed by land cover to produce erosion sensitivity, and then rainfall to produce erosion risk. The high erosion areas of the Island have been extracted from the soil erosion risk maps, whereby these areas can face land degradation problems and can be responsible for sediment discharge into wetlands located at the outlet of drainage basins. As such, drainage basins have been delineated using automatic catchment delineation tools and their percentage of high erosion areas computed. Basins with the greatest percentage of high erosion areas and particularly those that directly have a wetland at the outlet can be given priority for soil and water conservation efforts. The mapping reported in this paper can be adapted to other countries which need an erosion assessment for the identification of high erosion areas and priority action areas.

  4. Laboratory soil piping and internal erosion experiments: evaluation of a soil piping model for low-compacted soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil piping has been attributed as a potential mechanism of instability for embankments, hillslopes, dams, and streambanks. In fact, deterministic models have been proposed to predict soil piping and internal erosion. However, limited research has been conducted under controlled conditions to evalua...

  5. The International year of soils: thoughts on future directions for experiments in soil erosion research

    NASA Astrophysics Data System (ADS)

    Kuhn, Nikolaus J.

    2015-04-01

    The 2015 UN Year of Soils (IYS), implemented by the FAO, aims to increase awareness and understanding of the importance of soil for food security and essential ecosystem functions. The IYS has six specific objectives, ranging from raising the awareness among civil society and decision makers about the profound importance of soils, to the development of policies supporting the sustainable use of the non-renewable soil resource. For scientists and academic teachers using experiments to study soil erosion processes, two objectives appear of particular relevance. First is need for the rapid capacity enhancement for soil information collection and monitoring at all levels (global, regional and national). While at first glance, this objective appears to relate mostly to traditional mapping, sampling and monitoring, the threat of large-scale soil loss, at least with regards to their ecosystem services, illustrates the need for approaches of studying soils that avoids such irreversible destruction. Relying on often limited data and their extrapolation does not cover this need for soil information because rapid change of the drivers of change itself carry the risk of unprecedented soil reactions not covered by existing data sets. Experiments, on the other hand, offer the possibility to simulate and analyze future soil change in great detail. Furthermore, carefully designed experiments may also limit the actual effort involved in collecting the specific required information, e.g. by applying tests designed to study soil system behavior under controlled conditions, compared to field monitoring. For rainfall simulation, experiments should therefore involve the detailed study of erosion processes and include detailed recording and reporting of soil and rainfall properties. The development of a set of standardised rainfall simulations would widen the use data collected by such experiments. A second major area for rainfall simulation lies in the the education of the public about

  6. The Integrated Soil Erosion Risk Management Model of Central Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Setiawan, M. A.; Stoetter, J.; Sartohadi, J.; Christanto, N.

    2009-04-01

    Many types of soil erosion modeling have been developed worldwide; each of models has its own advantage and assumption based on the originated area. Ironically, in the tropical countries where the rainfall intensity is higher than other area, the soil erosion problem gain less attention. As in Indonesia, due the inadequate supporting data and method to dealing with, the soil erosion management appears to be least prior in the policy decision. Hence, there is increasing necessity towards the initiation and integration of risk management model in the soil erosion, to prevent further land degradation problem in Indonesia. The main research objective is to generate a model which can analyze the dynamic system of soil erosion problem. This model will comprehensively consider four main aspects within the dynamic system analysis, i.e.: soil erosion rate modeling, the tolerable soil erosion rate, total soil erosion cost, and soil erosion management measures. The generating model will involve some sub-software i.e. the PC Raster to maintain the soil erosion modeling, Powersim Constructor Ver. 2.5 as the tool to analyze the dynamic system and Python Ver. 2.6.1 to build the main Graphical User Interface model. The first step addressed in this research is figuring the most appropriate soil erosion model to be applied in Indonesia based on landscape, climate, and data availability condition. This appropriate model must have the simplicity aspect in input data but still deal with the process based analysis. By using the soil erosion model result, the total soil erosion cost will be calculated both on-site and off-site effect. The total soil erosion cost will be stated in Rupiah (Indonesian currency) and Dollar. That total result is then used as one of input parameters for the tolerable soil erosion rate. Subsequently, the tolerable soil erosion rate decides whether the soil erosion rate has exceeded the allowed value or not. If the soil erosion rate has bigger value than the

  7. The evaluation of the value of soil erosion prevention on wetlands in Beijing

    NASA Astrophysics Data System (ADS)

    Zhou, Bo; Zhu, Lin; Zhao, Wenji; Liu, Hao

    2011-02-01

    Wetland is an important part of the ecological system. It has an important role in soil erosion prevention. Without the protection of wetland, soil erosion will cause two aspects physical loss, including 1) the waste land caused by soil degradation and desertification; 2) nutrient contents loss. This paper takes all wetland in Beijing as object. This research includes investigation and research on indexes of soil erosion prevention in Beijing wetland ecological system. Two aspects of reduction soil waste and prevent soil fertility are studied. Potential and actual soil erosion are calculated using GIS and universal soil erosion equation based on collected data, with the difference of the two amounts is the soil conservation quantify, which will be converted to economic value. Research results show the economic value of Beijing wetland in the soil erosion prevention is 4,962.56 million Yuan. The river and swamp have the highest value; meanwhile, the rural wetland's value of soil erosion resistance is more than in the urban area. Wetland has the extremely vital significance to keep a good ecological environment in Beijing.

  8. Soil mapping and modelling for evaluation of the effects of historical and present-day soil erosion

    NASA Astrophysics Data System (ADS)

    Smetanova, Anna; Szwarczewski, Piotr

    2016-04-01

    The loess hilly lands in Danube Lowland are characterized by patchy soil-scape. The soil erosion processes uncover the subsurface, bright loess horizon, while non-eroded and colluvial soils are of the dark colour, in the chernozem area. With the modernisation of agriculture since the 1950's and in the process of collectivization, when small fields were merged into bigger, the soil degradation progressed. However, the analysis of historical sources and sediment archives showed the proofs of historical soil erosion. The objective of this study is to map the soil erosion patterns in connection of both pre- and post-collectivization landscape and to understand the accordingly developed soil erosion patterns. The combined methods of soil mapping and soil erosion modelling were applied in the part of the Trnavska pahorkatina Hilly Land in Danube Lowland. The detailed soil mapping in a zero-order catchment (0.28 km²) uncovered the removal of surface soil horizon of 0.6m or more, while the colluvial soils were about 1.1m deep. The soil properties and dating helped to describe the original soil profile in the valley bottom, and reconstruct the history of soil erosion in the catchment. The soil erosion model was applied using the reconstructed land use patterns in order to understand the effect of recent and historical soil erosion in the lowland landscape. This work was supported by the Slovak Research and Development Agency under the contract ESF-EC-0006-07 and APVV-0625-11; Anna Smetanová has received the support of the AgreenSkills fellowship (under grant agreement n°267196).

  9. Modulation of headcut soil erosion in rills due to upstream sediment loads

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Headcut erosion can severely accelerate soil loss in upland concentrated flows and lead to significant soil degradation in agricultural areas. Previous experimental work has demonstrated that actively migrating headcuts display systematic morphodynamic behavior, and impinging jet theory can provide...

  10. The Cannona Data Base: long-term field data for studies on soil management impact on runoff and erosion processes.

    NASA Astrophysics Data System (ADS)

    Biddoccu, Marcella; Ferraris, Stefano; Opsi, Francesca; Cavallo, Eugenio

    2014-05-01

    on water and soil conservation. The monitoring activities at the Cannona Experimental Site are currently carried out and implemented in order to improve the understanding of the soil management effects on soil hydrology, erosion and compaction in sloping vineyards. Land use and soil management strongly influence the hydrologic processes in the soil. In Italy vines are widely cultivated on hills and mountain slopes, within areas which are frequently affected by landslides. Such natural events are strictly related to hydrologic behavior of the soil, that drives the runoff formation on slopes and the consequent sediment delivery to water courses. Data from the CDB could be used in a multidisciplinary approach to investigate interactions among land use/ soil management and natural processes at different scales.

  11. Spatial distribution of soil erosion and suspended sediment transport rate for Chou-Shui river basin

    NASA Astrophysics Data System (ADS)

    Lin, Chin-Ping; Chen, Ching-Nuo; Wang, Yu-Min; Tsai, Chih-Heng; Tsai, Chang-Tai

    2014-10-01

    In this study, a Physiographic Soil Erosion-Deposition Model (PSED) is applied for better management of a watershed. The PSED model can effectively evaluate the key parameters of watershed management: surface runoff discharge, suspended sediment transport rate, quantity of soil erosion, and spatial distribution of soil erosion and deposition. A basin usually contains multiple watersheds. These watersheds may have complex topography and heterogeneous physiographic properties. The PSED model, containing a physiographic rainfall-runoff model and a basin scale erosion-deposition model, can simulate the physical mechanism of the entire erosion process based on a detailed calculation of bed-load transportation, surface soil entrainment, and the deposition mechanism. With the assistance of Geographic Information Systems (GIS), the PSED model can handle and analyze extremely large hydrologic and physiographic datasets and simulate the physical erosion process without the need for simplification. We verified the PSED model using three typhoon events and 40 rainfall events. The application of PSED to Chou-Shui River basin shows that the PSED model can accurately estimate discharge hydrographs, suspended sediment transport rates, and sediment yield. Additionally, we obtained reasonable quantities of soil erosion as well as the spatial distribution of soil erosion and deposition. The results show that the PSED model is capable of calculating spatially distributed soil erosion and suspended sediment transport rates for a basin with multiple watersheds even if these watersheds have complex topography and heterogeneous physiographic properties.

  12. Biological soil crusts in subtropical China and their influence on initial soil erosion

    NASA Astrophysics Data System (ADS)

    Seitz, Steffen; Goebes, Philipp; Kühn, Peter; Scholten, Thomas

    2014-05-01

    Soil is one of the most valuable resources we have on our planet. The erosion of this resource is a major environmental problem, in particular in subtropical China where high rainfall intensity causes severe and continuous soil losses. One of the main mechanisms controlling soil erosion is surface coverage, typically by vegetation, litter, stones and biological soil crusts (BSCs). BSCs play significant functional roles in soil systems, such as accelerating soil formation, changing water and nutrient cycling rates, enhancing soil stability and thus preventing erosion by wind or water. In initial ecosystems, cyanobacteria, algae, fungi, mosses and lichens are the first organisms to colonize the substrate; they form a biological crust within the first millimetres of the surface. BSCs and their effect on erosion are rarely mentioned in literature and most of the work done focussed on arid and semi-arid environments. This study aims to investigate the role of BSCs controlling the amount of runoff generated and sediment detached during soil erosion events in an initial ecosystem in subtropical China. The study took place on a deforested experimental site (BEF China) near Xingangshan, Jiangxi Province, PR China. We used a total number of 350 runoff plots (ROP, 40cmx40cm) to measure sediment discharge and surface runoff. BSC cover in each ROP was determined photogrammetrically in 4 time steps (autumn 2011, spring 2012, summer 2012 and summer 2013). Perpendicular images were taken and then processed to measure the coverage of BSCs using a 1 cm² digital grid overlay. Additionally BSCs were sampled in the field and identified by their taxonomy. In our ROPs we found 65 different moos, algae and lichen species, as well as cyanobacteria's. Mean BSC cover per ROP in 2013 was 17 % with a maximum of 62 % and a minimum of 0 %. Compared to stone cover with 3 %, our findings highlight the role of BSC in soil erosion processes. The total BSC covered area is slightly decreasing since

  13. High natural erosion rates are the backdrop for present-day soil erosion in the agricultural Middle Hills of Nepal

    NASA Astrophysics Data System (ADS)

    West, A. J.; Arnold, M.; AumaItre, G.; Bourles, D. L.; Keddadouche, K.; Bickle, M.; Ojha, T.

    2015-07-01

    Although agriculturally accelerated soil erosion is implicated in the unsustainable environmental degradation of mountain environments, such as in the Himalaya, the effects of land use can be challenging to quantify in many mountain settings because of the high and variable natural background rates of erosion. In this study, we present new long-term denudation rates, derived from cosmogenic 10Be analysis of quartz in river sediment from the Likhu Khola, a small agricultural river basin in the Middle Hills of central Nepal. Calculated long-term denudation rates, which reflect background natural erosion processes over 1000+ years prior to agricultural intensification, are similar to present-day sediment yields and to soil loss rates from terraces that are well maintained. Similarity in short- and long-term catchment-wide erosion rates for the Likhu is consistent with data from elsewhere in the Nepal Middle Hills but contrasts with the very large increases in short-term erosion rates seen in agricultural catchments in other steep mountain settings. Our results suggest that the large sediment fluxes exported from the Likhu and other Middle Hills rivers in the Himalaya are derived in large part from natural processes, rather than from soil erosion as a result of agricultural activity. Catchment-scale erosional fluxes may be similar over short and long timescales if both are dominated by mass wasting sources such as gullies, landslides, and debris flows (e.g., as is evident in the landslide-dominated Khudi Khola of the Nepal High Himalaya, based on compiled data). As a consequence, simple comparison of catchment-scale fluxes will not necessarily pinpoint land use effects on soils where these are only a small part of the total erosion budget, unless rates of mass wasting are also considered. Estimates of the mass wasting contribution to erosion in the Likhu imply catchment-averaged soil production rates on the order of ~ 0.25-0.35 mm yr-1, though rates of mass wasting are

  14. [Vegetation above-ground biomass and its affecting factors in water/wind erosion crisscross region on Loess Plateau].

    PubMed

    Wang, Jian-guo; Fan, Jun; Wang, Quan-jiu; Wang, Li

    2011-03-01

    Field investigations were conducted in Liudaogou small watershed in late September 2009 to study the differences of vegetation above-ground biomass, soil moisture content, and soil nutrient contents under different land use patterns, aimed to approach the vegetation above-ground biomass level and related affecting factors in typical small watershed in water/wind erosion crisscross region on Loess Plateau. The above-ground dry biomass of the main vegetations in Liudaogou was 177-2207 g x m(-2), and that in corn field, millet field, abandoned farmland, artificial grassland, natural grassland, and shrub land was 2097-2207, 518-775, 248-578, 280-545, 177-396, and 372-680 g x m(-2), respectively. The mean soil moisture content in 0-100 layer was the highest (14.2%) in farmlands and the lowest (10.9%) in shrub land. The coefficient of variation of soil moisture content was the greatest (26. 7% ) in abandoned farmland, indicating the strong spatial heterogeneity of soil moisture in this kind of farmland. The mean soil water storage was in the order of farmland > artificial grassland > natural grassland > shrub land. Soil dry layer was observed in alfalfa and caragana lands. There was a significant positive correlation (r = 0.639, P < 0.05) between above-ground dry biomass and 0-100 cm soil water storage, and also, a very significant positive correlation between above-ground fresh biomass and vegetation height. The above-ground biomass of the higher vegetations could potentially better control the wind and water erosion in the water/wind erosion crisscross region. Vegetation above-ground biomass was highly correlated with soil moisture and nutrient contents, but had no significant correlations with elevation, slope gradient, slope aspect, and soil bulk density. PMID:21657007

  15. Effects of cropping and tillage systems on soil erosion under climate change in Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion under future climate change is very likely to increase due to projected increases in frequency and magnitude of heavy storms. The objective of this study is to quantify the effects of common cropping and tillage systems on soil erosion and surface runoff during 2010-2039 in central Okl...

  16. Cropping and tillage systems effects on soil erosion under climate change in Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion under future climate change is very likely to increase due to projected increases in frequency and magnitude of heavy storms. The objective of this study is to quantify the effects of common cropping and tillage systems on soil erosion and surface runoff during 2010-2039 in central Okl...

  17. Mapping of soil erosion using remotely sensed data in Zombodze South, Swaziland

    NASA Astrophysics Data System (ADS)

    Manyatsi, Absalom M.; Ntshangase, Nomndeni

    Zombodze South is situated in the southern part of Swaziland. It has visible signs of soil erosion. However like many parts of the country, soil erosion has not been mapped. The area lacks soil conservation measures. The objective of the study was to map the spatial distribution of soil erosion, and to determine the perception of community members on soil erosion problems. IDRISI for Windows was used to produce 20 clusters from Landsat ETM data for January 1999. The clusters were allocated to five land cover classes based on a combination of use of “scatterplots” and NDVI values. Gullies were identified on digital aerial photos of the area, and digitized. Other land features such as settlements, roads and rivers were also digitized. A structured questionnaire was administered to 40 homesteads that were randomly selected from the 234 homesteads in the community to collect information on perception of communities on soil erosion, as well as their involvement in controlling soil erosion. About 4% of the area was eroded, with another 38% having very sparse vegetation cover. Gully erosion was prevalent in the southern part of the area. The limited soil erosion conservation measures in the area were undertaken by local school children as part of their school projects. The control measures suggested by members of the community included planting trees and grasses along the gullies, fencing of gullies and construction of check dams.

  18. The development of U.S. soil erosion prediction and modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion prediction technology began over 70 years ago when Austin Zingg published a relationship between soil erosion (by water) and land slope and length, followed shortly by a relationship that expanded this equation to include conservation practices. But, it was nearly 20 years before this w...

  19. Evaluation and Application of a Soil Erosion Model on the Columbia Plateau, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA-ARS Wind Erosion Prediction System (WEPS) was developed for soil conservation and environmental planning and is a process-based model that predicts soil erosion and PM10 (particle matter less than or equal to 10µm in diameter) emission. WEPS is comprised of seven submodels; all submodels se...

  20. Soil erosion assessment based on minimum polygons in the Yellow River basin, China

    NASA Astrophysics Data System (ADS)

    Ni, Jin-Ren; Li, Xiu-Xia; Borthwick, A. G. L.

    2008-01-01

    In the previous studies, a method was developed to assess soil erosion based on land use information. In this paper, we present another approach that uses environmental data to assess soil erosion. A soil erosion characteristic index EI is proposed, and its value is derived using the Analytic Hierarchy Process (AHP) technique based on standardized environmental information stored in minimum polygons that tile the erodible area under consideration. The approach is applied to a case study of the Yellow River basin, north China, where serious erosion is occurring. To represent different grades of soil erosion, the range of EI is divided into six levels according to standard grades of soil erosion intensity. The application indicates that the method deals properly with data scarcity, with the results giving a satisfactory representation of the characteristics of soil erosion in the Yellow River basin. The spatial-temporal distribution of EI in the Yellow River basin is predicted, and the results interpreted to give the long-term trend and state of soil depletion. Comparisons are given between EI and surveyed soil erosion zoning maps for the Yellow River basin at the end of the 1980s and 1990s. The output reliability and the approach applicability in smaller spatial scales are investigated in a case study of Zhifanggou basin.

  1. Impact of Precipitation Changes on Runoff and Soil Erosion in Korea using CLIGEN and WEPP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The quality of spatially and temporally distributed weather information is critical in soil erosion model results because of the primary influence of rainfall on runoff and soil movement. Detailed climate data for the Water Erosion Prediction Project (WEPP) model can be generated by a climate genera...

  2. Towards new-generation soil erosion modeling: Building a unified omnivorous model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion is a global threat to agricultural production, and results in off-site sediment and nutrient losses that negatively impact water and air quality. Models are mathematical equations used to estimate the amount of soil lost from a land air, due to the erosive forces of water or wind. Early...

  3. Climate change impacts on soil erosion in the Great Lakes Region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying changes in potential soil erosion under projections of changing climate is important for the sustainable management of land resources, especially for regions dominated by agricultural land use, as soil loss estimates will be helpful in identifying areas susceptible to erosion, targeting ...

  4. Developing soil erodibility prediction equations for the Rangeland Hydrology and Erosion Model (RHEM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erodibility is a key factor for estimating soil erosion using physically based models. In this study, a new parameterization approach for estimating erodibility was developed for the Rangeland Hydrology and Erosion Model (RHEM). The approach uses empirical equations that were developed by apply...

  5. A Simple Close Range Photogrammetry Technique to Assess Soil Erosion in the Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evaluating the performance of a soil erosion prediction model depends on the ability to accurately measure the gain or loss of sediment in an area. Recent development in acquiring detailed surface elevation data (DEM) makes it feasible to assess soil erosion and deposition spatially. Digital photogr...

  6. Model development and applications at the USDA-ARS National Soil Erosion Research Laboratory

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The United States Department of Agriculture (USDA) has a long history of development of soil erosion prediction technology, initially with empirical equations like the Universal Soil Loss Equation (USLE), and more recently with process-based models such as the Water Erosion Prediction Project (WEPP)...

  7. Potential change in soil erosion trend and risk during 2010-2039 in central Oklahoma, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential for global climate changes to increase risk of soil erosion is clear, but quantitative analysis of this risk is limited due to high spatial and temporal variability in projected climate change scenarios. For accurate prediction of soil erosion risk under climate change, climate chang...

  8. Uncertainty of climate change impacts on soil erosion from cropland in central Oklahoma

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Impacts of climate change on soil erosion and the potential need for additional conservation actions are typically estimated by applying a hydrologic and soil erosion model under present and future climate conditions defined by an emission scenario. Projecting future climate conditions harbors sever...

  9. Deriving parameters of a fundamental detachment model for cohesive soils from flume and jet erosion tests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The erosion rate of cohesive soils is commonly quantified using the excess shear stress equation, dependent on two major soil parameters: the critical shear stress and the erodibility coefficient. A submerged jet test (JET – Jet Erosion Test) is one method that has been developed for measuring thes...

  10. Pore water effects on soil erodibility and its implication in ephemeral gully erosion modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ephemeral gully erosion is the main source of sediment from the agricultural landscape, unfortunately, it has been overlooked in traditional soil erosion assessment. Field observations, and subsequent support from controlled lab experiments, have shown the linkage between transient soil hydraulic co...

  11. Changes in forcing factors affecting coastal and shallow water erosion in the future Arctic climate change projections.

    NASA Astrophysics Data System (ADS)

    Dobrynin, Mikhail; Razumov, Sergey; Brovkin, Victor; Ilyina, Tatiana; Grigoriev, Mikhail

    2016-04-01

    Driving factors of seabed and coastal erosion in the Arctic can be classified as thermal and mechanical. Thermal factors such as air and ocean temperatures affect the seabed and coastal ground temperatures. Mechanical factors such as ocean currents and surface gravity waves contribute to the seabed and costal erosion due to shear stress. Due to polar amplification, the Arctic experiences strong increase in air and water temperature, sea-ice loss and changes in the ocean and atmospheric circulation, temperature and wind distribution. These climatic changes lead to changes in factors driving seabed and coastal erosion, which is expected to accelerate in the shallow Arctic regions such as the Laptev sea and East Siberian sea. In these regions, the coastal line to a large extent consists of frozen rocks, sediments and organic soils including ground ice. The increase of erosion rate of the coastal line will increase the release of organic and inorganic matter from thawed permafrost. Dynamics of thermal and mechanical drivers of seabed and coastal erosion in the present and future climate change (RCP8.5 scenario) simulated by the CMIP5 version of the MPI Earth system model and wave model WAM will be presented. Special attention will be given to changes in the air temperature, wind dynamics and development of new waves system in the ``ice-free'' Arctic and its role in the seabed and coastal erosion.

  12. The history of human-induced soil erosion: Geomorphic legacies, early descriptions and research, and the development of soil conservation—A global synopsis

    NASA Astrophysics Data System (ADS)

    Dotterweich, Markus

    2013-11-01

    This paper presents a global synopsis about the geomorphic evidence of soil erosion in humid and semihumid areas since the beginning of agriculture. Historical documents, starting from ancient records to data from the mid-twentieth century and numerous literature reviews form an extensive assortment of examples that show how soil erosion has been perceived previously by scholars, land surveyors, farmers, land owners, researchers, and policy makers. Examples have been selected from ancient Greek and Roman Times and from central Europe, southern Africa, North America, the Chinese Loess Plateau, Australia, New Zealand, and Easter Island. Furthermore, a comprehensive collection on the development of soil erosion research and soil conservation has been provided, with a particular focus on Germany and the USA. Geomorphic evidence shows that most of the agriculturally used slopes in the Old and New Worlds had already been affected by soil erosion in earlier, prehistoric times. Early descriptions of soil erosion are often very vague. With regard to the Roman Times, geomorphic evidence shows seemingly opposing results, ranging from massive devastation to landscapes remaining stable for centuries. Unfortunately, historical documentation is lacking. In the following centuries, historical records become more frequent and more precise and observations on extreme soil erosion events are prominent. Sometimes they can be clearly linked to geomorphic evidence in the field. The advent of professional soil conservation took place in the late eighteenth century. The first extensive essay on soil conservation known to the Western world was published in Germany in 1815. The rise of professional soil conservation occurred in the late nineteenth and early twentieth centuries. Soil remediation and flood prevention programs were initiated, but the long-term success of these actions remains controversial. In recent years, increasing interest is to recover any traditional knowledge of soil

  13. Extreme soil erosion rates in citrus slope plantations and control strategies. A literature review

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Ángel González Peñaloza, Félix; Pereira, Paulo; Reyes Ruiz Gallardo, José; García Orenes, Fuensanta; Burguet, María

    2013-04-01

    Soil Erosion is a natural process that shapes the Earth. Due to the impact of agriculture, soil erosion rates increase, landforms show gullies and rills, and soils are depleted. In the Mediterranean, wheat, olive and vineyards were the main agriculture products, but new plantations are being found in sloping terrain due to the drip-irrigation. This new strategy results in the removal of the traditional terraces in order to make suitable for mechanization the agriculture plantation. Citrus is a clear example of the impact of the new chemical agriculture with a high investment in herbicides, pesticides, mechanisation, land levelling and drip computer controlled irrigation systems. The new plantation of citrus orchards is found in the Mediterranean, but also in California, Florida, China and Brazil. Chile, Argentina, and South Africa are other producers that are moving to an industrial production of citrus. This paper shows how the citrus plantations are found as one of the most aggressive plantation due to the increase in soil erosion, and how we can apply successful control strategies. The research into the high erosion rates of citrus orchard built on the slopes are mainly found in China (Wu et al., 1997; Xu et al., 2010; Wang et al., 2011; Wu et al., 2011; Liu et al., 2011; Lü et al., 2011; Xu et al., 2012) and in the Mediterranean (Cerdà and Jurgensen, 2008; 2009; Cerdà et al., 2009a; 2009b; Cerdà et al., 2011; 2012) Most of the research done devoted to the measurements of the soil losses but also some research is done related to the soil properties (Lu et al., 1997; Lü et al., 2012; Xu et al., 2012) and the impact of cover crops to reduce the soil losses (Lavigne et al., 2012; Le Bellec et al., 2012) and the use of residues such as dried citrus peel in order to reduce the soil losses. There are 116 million tonnes of citrus produced yearly, and this affects a large surface of the best land. The citrus orchards are moving from flood irrigated to drip

  14. Estimation on soil erosion dynamics using stable isotope ratios of soil organic matter

    NASA Astrophysics Data System (ADS)

    Jakab, Gergely; Zacháry, Dóra; Szalai, Zoltán; Ringer, Marianna; Szabó, Judit

    2016-04-01

    Stable isotopes are a powerful and widely used tool for tracing biogeochemical processes across the ecosystem. Measuring the stable carbon, oxygen and hydrogen isotope composition of CO2 and H2O compounds and organic matter is useful for examining the soil, plant and atmospheric carbon and water pools as they isotopic composition is altered during vegetation-soil-atmosphere exchange processes (e.g., evapotranspiration, carbon assimilation and respiration). Stable carbon and nitrogen isotopes can serve as a tracer for C and N input by plants into the soil, C turnover and soil organic matter studies. In addition, coupling of isotopic tracers with molecular biology approaches and biomarkers can lead to a better understanding of the soil ecosystem processes. This study aims to estimate soil erosion deposition and redistribution processes at catena scale on the basis of stable isotope results. Soil samples were taken from the total depth of the solum along two catenas on an intensively tilled arable Cambisol. Highest δC13 values were found on the most eroded spots, while on the deposition areas significant differences were measured among the sedimented layers. The lowest δC13 value was in the buried horizon at around 120 cm depth. From this horizon δC13 values slightly increased in both upward and downward directions. However the total organic carbon concentration was highly fluctuated in the deposited profiles and have not reached its maximum in this horizon isotope results suggest that this horizon could have been the original soil surface prior to the main erosion events. In this way the use of stable isotope changes in space can provide additional information on soil redistribution due to tillage erosion. National Hungarian Research Found K100180, G. Jakab was supported by the János Bolyai fellowship of the HAS.

  15. Detection of soil erosion within pinyon-juniper woodlands using Thematic Mapper (TM) satellite data

    NASA Technical Reports Server (NTRS)

    Price, Kevin P.; Ridd, Merrill K.

    1991-01-01

    The sensitivity of Landsat TM data for detecting soil erosion within pinyon-juniper woodlands, and the potential of the spectral data for assigning the universal soil loss equation (USLE) crop managemnent (C) factor to varying cover types within the woodlands are assessed. Results show greatly accelerated rates of soil erosion on pinyon-juniper sites. Percent cover by pinyon-juniper, total soil-loss, and total nonliving ground cover accounted for nearly 70 percent of the variability in TM channels 2, 3, 4, and 5. TM spectral data were consistently better predictors of soil erosion than the biotic and abiotic field variables. Satellite data were more sensitive to vegetation variation than the USLE C factor, and USLE was found to be a poor predictor of soil loss on pinyon-juniper sites. A new string-to-ground soil erosion prediction technique is introduced.

  16. Soil erosion rates from mixed soil and gravel surfaces in a wind tunnel: A preliminary report

    SciTech Connect

    Ligotke, M.W.

    1988-12-01

    Tests of wind erosion were performed in a controlled-environment wind tunnel to support the development of natural-material protective barriers for long-term isolation of radioactive waste. Barrier performance standards currently being developed for internal and external barrier performance are expected to mandate a surface layer that is resistant to wind erosion. The purpose of this study was to initiate a series of tests to determine suitable soil and gravel mixtures for such a barrier and to test worst-case surface layer conditions under the influence of high wind speeds. Six mixed soil and gravel surfaces were prepared, weathered to represent natural wind-blown desert areas, and subjected to controlled wind erosion forces in a wind tunnel. The applied erosive forces, including surface shear forces, were characterized to provide a means of relating wind tunnel results with actual field conditions. Soil particle losses from the surfaces caused by suspension, saltation, and surface creep were monitored by aerosol sample probes and mass balance measurements. 23 refs., 22 figs., 3 tabs.

  17. Spatio-temporal assessment of soil erosion risk in different agricultural zones of the Inle Lake region, southern Shan State, Myanmar.

    PubMed

    Htwe, Thin Nwe; Brinkmann, Katja; Buerkert, Andreas

    2015-10-01

    Myanmar is one of Southeast Asia's climatically most diverse countries, where sheet, rill, and gully erosion affect crop yields and subsequently livelihood strategies of many people. In the unique wetland ecosystem of Inle Lake, soil erosion in surrounding uplands lead to sedimentation and pollution of the water body. The current study uses the Revised Universal Soil Loss Equation (RUSLE) to identify soil erosion risks of the Inle Lake region in space and time and to assess the relationship between soil erosion and degradation for different agricultural zones and cropping systems. Altogether, 85% of soil losses occurred on barren land along the steep slopes. The hotspot of soil erosion risk is situated in the western uplands characterized by unsustainable land use practices combined with a steep topography. The estimated average soil losses amounted to 19.9, 10.1, and 26.2 t ha(-1) yr(-1) in 1989, 2000, and 2009, respectively. These fluctuations were mainly the results of changes in precipitation and land cover (deforestation (-19%) and expansion of annual cropland (+35%) from 1989 to 2009). Most farmers in the study area have not yet adopted effective soil protection measures to mitigate the effects of soil erosion such as land degradation and water pollution of the lake reservoir. This urgently needs to be addressed by policy makers and extension services. PMID:26350794

  18. Climatic and agricultural drivers of soil erosion in Africa

    NASA Astrophysics Data System (ADS)

    Irvine, Brian; Kirkby, Mike; Fleskens, Luuk

    2015-04-01

    Soil erosion was the most frequently identified driver of land degradation across a selection of global research sites within the DESIRE-EU project. The PESERA model was adopted in the project to upscale field results and consider the potential biophysical impact both with and without stakeholder selected sustainable land management (SLM) technologies in place. The PESERA model was combined with the DESMICE economic model and focussed on forecasting the regional effects of combating desertification both in environmental and socio-economical terms. The PESERA-DESMICE approach is further developed in the WAHARA project to consider the potential of a range of water harvesting technologies to improve biophysical conditions. Modelling in the WAHARA project considers detail of water harvesting technologies at the study site scale through to a coarser application at the continental scale with the latter being informed by the detail provided by study site observations an approach adopted in DESIRE-EU. The PESERA-DESMICE approach considers the difference between a baseline scenario and a (water harvesting) technology scenario at both scales in terms of productivity, financial viability and scope for reducing erosion risk. This paper considers the continental scale and focuses on estimating the impact of in-situ water harvesting technologies across Africa under current and future agricultural and climate pressure. PESERA is adopted in this continental application as it implicitly considers the impact of land-use and climate and can be readily amended to simulate in-situ WHT. Input data for PESERA; land use, management (crop type and planting dates), soil data and topography are derived from global data resources. Climate data for present and future scenarios are available through the QUEST-GSI initiative, where future scenarios are based on the outputs of seven GCM's.

  19. Improvement of erosion risk modelling using soil information derived from aerial Vis-NIR imagery

    NASA Astrophysics Data System (ADS)

    Ciampalini, Rossano; Raclot, Damien; Le Bissonnais, Yves

    2016-04-01

    The aim of this research is to test the benefit of the hyperspectral imagery in soil surface properties characterisation for soil erosion modelling purposes. The research area is the Lebna catchment located in the in the north of Tunisia (Cap Bon Region). Soil erosion is evaluated with the use of two different soil erosion models: PESERA (Pan-European Soil Erosion Risk Assessment already used for the soil erosion risk mapping for the European Union, Kirkby et al., 2008) and Mesales (Regional Modelling of Soil Erosion Risk developed by Le Bissonnais et al., 1998, 2002); for that, different sources for soil properties and derived parameters such as soil erodibility map and soil crusting map have been evaluated with use of four different supports: 1) IAO soil map (IAO, 2000), 2) Carte Agricole - CA - (Ministry of Agriculture, Tunisia), 3) Hyperspectral VIS-NIR map - HY - (Gomez et al., 2012; Ciampalini t al., 2012), and, 3) a here developed Hybrid map - CY - integrating information from Hyperspectral VIS-NIR and pedological maps. Results show that the data source has a high influence on the estimation of the parameters for both the models with a more evident sensitivity for Pesera. With regard to the classical pedological data, the VIS-NIR data clearly ameliorates the spatialization of the texture, then, the spatial detail of the results. Differences in the output using different maps are more important in Pesera model than in Mesales showing no-change ranges of about 15 to 41% and 53 to 67%, respectively.

  20. Ash after forest fires. Effects on soil hydrology and erosion

    NASA Astrophysics Data System (ADS)

    Bodí, Merche B.

    2013-04-01

    Hillslopes were though to be most susceptible to enhanced hydro-geomorphological responses immediately following burning, with susceptibility declining during the first months or years depending on the soil and vegetation recovery. However, Cerdà (1998) found some indices in that immediately after the fire, the thin wettable ash layer that typically covers the ground could absorb rainfall and prevent or delay the onset of overland flow and associated erosion. Therefore the time lag while ash remains on the ground become of crucial importance to protect the soil after a wildfire. The effect of this ash layer was rarely been considered in detail because ash has often been reduced or redistributed by wind or water erosion before the onset of monitoring and thus the data collection typically begun some weeks or month after the fire. The first papers focussed only on ash and its hydrological effects were published by Cerdà and Doerr (2008) and by Woods and Balfour (2008). The results showed that the soil covered with ash indeed reduced and delayed surface runoff, reduced soil splash detachment and produced lower sediment yield compared to bare terrain. However, these findings arose more questions, as for instance: Why in other research there were indices that ash reduces infiltration? what is the mechanism by which why ash reduces overland flow? The research went further with Bodí PhD. First of all, it was crucial the agreement on the fact that the material "ash" is very variable depending on the original vegetation and the type and temperature of combustion. Therefore ash properties are different between wildfires even and within a fire. This is the main reason of its different effects and thus ash not always reduces runoff and sediment yield. In this way, depending on the nature of ash, it can increase overland flow if it is crusted (usually it contains a high content of calcium carbonate), it is water repellent (with high contents of organic carbon and specially

  1. A laboratory rainfall simulator to study the soil erosion and runoff water

    NASA Astrophysics Data System (ADS)

    Cancelo González, Javier; Rial, M. E.; Díaz-Fierros, Francisco

    2010-05-01

    The soil erosion and the runoff water composition in some areas affected by forest fires or submitted to intensive agriculture are an important factor to keep an account, particularly in sensitive areas like estuary and rias that have a high importance in the socioeconomic development of some regions. An understanding of runoff production indicates the processes by which pollutants reach streams and also indicates the management techniques that might be uses to minimize the discharge of these materials into surface waters. One of the most methodology implemented in the soil erosion studies is a rainfall simulation. This method can reproduce the natural soil degradation processes in field or laboratory experiences. With the aim of improve the rainfall-runoff generation, a laboratory rainfall simulator which incorporates a fan-like intermittent water jet system for rainfall generation were modified. The major change made to the rainfall simulator consist in a system to coupling stainless steel boxes, whose dimensions are 12 x 20 x 45 centimeters, and it allows to place soil samples under the rainfall simulator. Previously these boxes were used to take soil samples in field with more of 20 centimeters of depth, causing the minimum disturbance in their properties and structure. These new implementations in the rainfall simulator also allow collect water samples of runoff in two ways: firstly, the rain water that constituted the overland flow or direct runoff and besides the rain water seeps into the soil by the process of infiltration and contributed to the subsurface runoff. Among main the variables controlled in the rainfall simulations were the soil slope and the intensity and duration of rainfall. With the aim of test the prototype, six soil samples were collected in the same sampling point and subjected to rainfall simulations in laboratory with the same intensity and duration. Two samples will constitute the control test, and they were fully undisturbed, and four

  2. Soil erosion rates in rangelands of northeastern Patagonia: A dendrogeomorphological analysis using exposed shrub roots

    NASA Astrophysics Data System (ADS)

    Chartier, Marcelo Pablo; Rostagno, César Mario; Roig, Fidel Alejandro

    2009-05-01

    Soil erosion is an important process of land degradation in many rangelands and a significant driver of desertification in the world's drylands. Dendrogeomorphology is an alternative to traditional methods for determining soil erosion rate. Specifically, the vertical distance between the upper portion of exposed roots and the actual soil surface can be used as a bioindicator of erosion since plant establishment. In this study, we determined (i) the soil erosion rate from exposed roots of the dwarf shrub Margyricarpus pinnatus [Lam.] Kuntze in two ecological sites in the northeastern rangelands of Patagonia and (ii) the relationship between shrub age and upper root diameter. We selected two ecological sites, a pediment-like plateau and a flank pediment, where the dominant soils were Xeric Haplocalcids and Xeric Calciargids, respectively. The soil erosion rates in the pediment-like plateau and in the flank pediment were 2.4 and 3.1 mm yr - 1 , respectively. Data clearly indicate a high rate of soil erosion during the mean 8-year life span of the dwarf shrubs in degraded patches, which represent ~ 10% of surface cover in the study area. Simple linear regression analysis yielded a highly significant predictive model for age estimation of M. pinnatus plants using the upper root diameter as a predictor variable. The measurement of ground lowering against datable exposed roots represents a simple method for the determination of soil erosion rates. In combination with other soil surface features, it was used to infer the episodic nature of soil erosion. This approach could be particularly useful for monitoring the effects of land management practices on recent soil erosion and for the establishment of records in regions where historical data regarding this process are scarce or absent.

  3. Short and long term effects of bioturbation on soil erosion, water resources and soil development in an arid environment

    NASA Astrophysics Data System (ADS)

    Yair, A.

    1995-09-01

    The importance of vegetal cover on soil erosion processes has been recognized for a long time. However, the short and long term effects of faunal activity on soil erosion and soil development had been largely overlooked by geomorphologists. The study of runoff and erosion processes in the Negev desert indicated pronounced systematic differences in sediment concentration and soil erosion rates between rocky and colluvial surfaces. Erosion rates were always higher on the former than on the latter. Field observations drew attention to an intense burrowing and digging activity conducted mainly by Isopods and Porcupines. The monitoring of this activity, based on a grid system, which consists of rows 5 m wide, lasted ten consecutive years. Data obtained suggest the existence of a strong link between the spatial pattern of bioturbation and that of soil erosion. The study also examines, through feedback processes, the regulatory role of bioturbation on the spatial distribution of water availability; soil moisture and soil forming processes. Due to bioturbation two distinct environments were recognised. The rocky environment which is characterized by a positive feedback with a high water availability and low soil salinity; and the soil covered areas where a negative feedback results in low water availability and a high soil salinity.

  4. Karst bare slope soil erosion and soil quality: a simulation case study

    NASA Astrophysics Data System (ADS)

    Dai, Q.; Liu, Z.; Shao, H.; Yang, Z.

    2015-06-01

    The influence on soil erosion by different bedrock bareness ratios, different rainfall intensities, different underground pore fissure degrees and rainfall duration are researched through manual simulation of microrelief characteristics of karst bare slopes and underground karst crack construction in combination with artificial simulation of rainfall experiment. The results show that firstly, when the rainfall intensity is small (30 and 50 mm h-1), no bottom load loss is produced on the surface, and surface and underground runoff and sediment production is increased with the increasing of rainfall intensity; secondly, surface runoff and sediment production reduced with increased underground pore fissure degree, while underground runoff and sediment production increased; thirdly, raindrops hit the surface, forming a crust with rainfall duration. The formation of crusts increases surface runoff erosion and reduces soil infiltration rate. Increasing of surface runoff erosion damaged crust and increased soil seepage rate. Raindrops continued to hit the surface, leading the formation of crust. Soil permeability showed volatility which were from reduction to increases and reduction, and so on. Surface and subsurface runoff were volatility with rainfall duration; fourthly, when rock bareness ratio is 50% and rainfall intensities are 30 and 50 mm h-1, runoff is not produced on the surface, and the slope runoff and sediment production presents a fluctuating change with increased rock bareness ratio; fifthly, the correlation degree between the slope runoff and sediment production and all factors are as follows: rainfall intensity > rainfall duration > underground pore fissure degree > bed rock bareness ratio.

  5. Karst bare slope soil erosion and soil quality: a simulation case study

    NASA Astrophysics Data System (ADS)

    Dai, Q.; Liu, Z.; Shao, H.; Yang, Z.

    2015-07-01

    The influence on soil erosion by different bedrock bareness ratios, different rainfall intensities, different underground pore fissure degrees and rainfall duration are researched through manual simulation of microrelief characteristics of karst bare slopes and underground karst crack construction in combination with artificial simulation of rainfall experiment. The results show that firstly, when the rainfall intensity is small (30 and 50 mm h-1), no bottom load loss is produced on the surface, and surface runoff, underground runoff and sediment production are increased with the increasing of rainfall intensity. Secondly, surface runoff and sediment production reduced with increased underground pore fissure degree, while underground runoff and sediment production increased. Thirdly, raindrops hit the surface, forming a crust with rainfall duration. The formation of crusts increases surface runoff erosion and reduces soil infiltration rate. This formation also increases surface-runoff-erosion-damaged crust and increased soil seepage rate. Raindrops continued to hit the surface, leading the formation of crust. Soil permeability showed volatility which was from reduction to increases, reduction, and so on. Surface and subsurface runoff were volatile with rainfall duration. Fourthly, when rock bareness ratio is 50 % and rainfall intensities are 30 and 50 mm h-1, runoff is not produced on the surface, and the slope runoff and sediment production present a fluctuating change with increased rock bareness ratio. Fifthly, the correlation degree between the slope runoff and sediment production and all factors are as follows: rainfall intensity-rainfall duration-underground pore fissure degree-bedrock bareness ratio.

  6. Effect of some surface and subsurface attributes on soil water erosion

    NASA Astrophysics Data System (ADS)

    Bertol, Ildegardis; César Ramos, Júlio; Vidal Vázquez, Eva; Mirás Avalos, José Manuel

    2013-04-01

    Soil erosion is a complex phenomenon depending on climate, topography, soil intrinsic characteristics, crop and residue cover, and management and conservation practices that may be accelerated by man activities. Within the above mentioned factors, soil cover and soil management most influence soil erosion. Soil management includes mechanical mobilization and in soil conservationist systems soil residues are mobilized for increasing soil surface roughness. Even if soil roughness is ephemeral, it increases soil water storage and sediment retention in surface microdepressions, which contributes to decrease water erosion. Conservationist soil management systems also maintain the soil surface covered by crop residues, which are more persistent than roughness and contribute to dissipate kinetic energy from raindrops and partly also from runoff. Crop residues are more efficient than soil roughness in controlling water erosion because of its ability to retain detached soil particles. The objective of this study was to assess the efficiency of both soil cover by crop residues and soil surface roughness in controlling water erosion. A field experiments was performed on an Inceptisol in South Brazil under simulated rainfall conditions during 2012. The following treatments were evaluated: 1) residues of Italian ryegrass (Lolium multiflorum), 2) residues of common vetch (Vicia sativa), 3) scarification after cultivation of Italian ryegrass, 4) scarification after cultivation of common vetch, 5) scarified bare soil with high roughness as a control. Treatments #1 and 2 involved no-tilled soil with a rather smooth soil surface, where roots and crop residues of the previous crop were maintained. Treatments # 3 and 4 involved a rather high roughness, absence of previous crop residues and maintenance of antecedent roots. Experimental plots were 11 m long and 3.5 m wide with an area of 38.5 m2. Six successive simulated rainfall tests were applied using a rotating-boom rain simulator

  7. The Effect of Leaf Litter Cover on Surface Runoff and Soil Erosion in Northern China

    PubMed Central

    Li, Xiang; Niu, Jianzhi; Xie, Baoyuan

    2014-01-01

    The role of leaf litter in hydrological processes and soil erosion of forest ecosystems is poorly understood. A field experiment was conducted under simulated rainfall in runoff plots with a slope of 10%. Two common types of litter in North China (from Quercus variabilis, representing broadleaf litter, and Pinus tabulaeformis, representing needle leaf litter), four amounts of litter, and five rainfall intensities were tested. Results revealed that the litter reduced runoff and delayed the beginning of runoff, but significantly reduced soil loss (p<0.05). Average runoff yield was 29.5% and 31.3% less than bare-soil plot, and for Q. variabilis and P. tabulaeformis, respectively, and average sediment yield was 85.1% and 79.9% lower. Rainfall intensity significantly affected runoff (R = 0.99, p<0.05), and the efficiency in runoff reduction by litter decreased considerably. Runoff yield and the runoff coefficient increased dramatically by 72.9 and 5.4 times, respectively. The period of time before runoff appeared decreased approximately 96.7% when rainfall intensity increased from 5.7 to 75.6 mm h−1. Broadleaf and needle leaf litter showed similarly relevant effects on runoff and soil erosion control, since no significant differences (p≤0.05) were observed in runoff and sediment variables between two litter-covered plots. In contrast, litter mass was probably not a main factor in determining runoff and sediment because a significant correlation was found only with sediment in Q. variabilis litter plot. Finally, runoff yield was significantly correlated (p<0.05) with sediment yield. These results suggest that the protective role of leaf litter in runoff and erosion processes was crucial, and both rainfall intensity and litter characteristics had an impact on these processes. PMID:25232858

  8. Assessment of soil erosion sensitivity and analysis of sensitivity factors in the Tongbai-Dabie mountainous area of China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion reduces crop productivity and creates negative impacts on water quality. Soil erosion by water has become a problem worldwide and as concerns about the environment continue to grow, soil erosion remains a very active area of scientific research. In this study, based on advanced remote s...

  9. Runoff erosion and nutrient depletion in five Mediterranean soils of NE Spain under different land use.

    PubMed

    Pardini, Giovanni; Gispert, Maria; Dunjó, Gemma

    2003-06-20

    environment, indicating that reforestation followed by insufficient forest management may negatively affect both soil properties and response to the erosive action of rainfall. PMID:12798105

  10. Reduction of the efficacy of biochar as soil amendment by soil erosion

    NASA Astrophysics Data System (ADS)

    Fister, Wolfgang; Heckrath, Goswin; Greenwood, Philip; Kuhn, Nikolaus J.

    2014-05-01

    Biochar is primarily used as soil amendment to improve soil quality and to sequester more carbon (C) to increase both medium- and long-term soil C stocks. These positive effects are obviously diminished if biochar is eroded and transported out of the field. Due to its low bulk density, the preferential mobilization and redistribution of biochar in the landscape seems probable. Therefore, the question has been raised in recent years of how vulnerable biochar actually is to soil erosion. This is especially relevant on soils which are regularly cultivated and are vulnerable to soil erosion themselves. However, so far few studies about the erodibility of biochar exist and the answer to this question is still unknown. It is therefore important to further our knowledge about mobilization and transport behaviour of biochar. Moreover, such knowledge could have profound economic implications for farmers committed to its use, as a high net annual loss of biochar by erosion could exceed any net annual economic gain. The overall objective of this study was, therefore, to investigate the erodibility of biochar, when erosion events occur directly or soon after its application. The estimation of the financial value of the eroded biochar and its cost-effectiveness were scaled up from plot to field scale. In this investigation, the biochar was applied to the soil surface of three plots on a recently cultivated sandy field near Viborg in northern Jutland, Denmark at concentrations equivalent to 1.5-2.0 kg m-2. After application, the biochar was manually incorporated into the till-zone (20cm). With the Portable Wind and Rainfall Simulator erosion events of a duration of 30 minutes and with a rainfall intensity of approx. 90 mm h-1 were conducted on both biochar and reference plots. The erodibility of biochar by wind erosion was due to very rainy wet soil surface conditions, tested with dried soil in the laboratory, in order to be able to at least reflect the worst case scenario. The

  11. Verification and completion of a soil data base for process based erosion model applications in Mato Grosso/Brazil

    NASA Astrophysics Data System (ADS)

    Schindewolf, Marcus; Schultze, Nico; Schönke, Daniela; Amorim, Ricardo S. S.; Schmidt, Jürgen

    2014-05-01

    The study area of central Mato Grosso is subjected to severe soil erosion. Continuous erosion leads to massive losses of top soil and related organic carbon. Consequently agricultural soil soils suffer a drop in soil fertility which only can be balanced by mineral fertilization. In order to control soil degradation and organic carbon losses of Mato Grosso cropland soils a process based soil loss and deposition model is used. Applying the model it will be possible to: - identify the main areas affected by soil erosion or deposition in different scales under present and future climate and socio-economic conditions - estimate the related nutrient and organic carbon losses/yields - figure out site-related causes of soil mobilization/deposition - locate sediment and sediment related nutrient and organic matter pass over points into surface water bodies - estimate the impacts of climate and land use changes on the losses of top soil, sediment bound nutrients and organic carbon. Model input parameters include digital elevation data, precipitation characteristics and standard soil properties as particle size distribution, total organic carbon (TOC) and bulk density. The effects of different types of land use and agricultural management practices are accounted for by varying site-specific parameters predominantly related to soil surface properties such as erosional resistance, hydraulic roughness and percentage ground cover. In this context the existing EROSION 3D soil parameter data base deducted from large scale rainfall simulations in Germany is verified for application in the study area, using small scale disc type rainfall simulator with an additional runoff reflux approach. Thus it's possible to enlarge virtual plot length up to at least 10 m. Experimental plots are located in Cuiabá region of central Mato Grosso in order to cover the most relevant land use variants and tillage practices in the region. Results show that derived model parameters are highly influenced

  12. An evaluation of soil erosion hazard: A case study in Southern Africa using geomatics technologies

    NASA Astrophysics Data System (ADS)

    Eiswerth, Barbara Alice

    Accelerated soil erosion in Malawi, Southern Africa, increasingly threatens agricultural productivity, given current and projected population growth trends. Previous attempts to document soil erosion potential have had limited success, lacking appropriate information and diagnostic tools. This study utilized geomatics technologies and the latest available information from topography, soils, climate, vegetation, and land use of a watershed in southern Malawi. The Soil Loss Estimation Model for Southern Africa (SLEMSA), developed for conditions in Zimbabwe, was evaluated and used to create a soil erosion hazard map for the watershed under Malawi conditions. The SLEMSA sub-models of cover, soil loss, and topography were computed from energy interception, rainfall energy, and soil erodibility, and slope length and steepness, respectively. Geomatics technologies including remote sensing and Geographic Information Systems (GIS) provided the tools with which land cover/land use, a digital elevation model, and slope length and steepness were extracted and integrated with rainfall and soils spatial information. Geomatics technologies enable rapid update of the model as new and better data sets become available. Sensitivity analyses of the SLEMSA model revealed that rainfall energy and slope steepness have the greatest influence on soil erosion hazard estimates in this watershed. Energy interception was intermediate in sensitivity level, whereas slope length and soil erodibility ranked lowest. Energy interception and soil erodibility were shown by parameter behavior analysis to behave in a linear fashion with respect to soil erosion hazard, whereas rainfall energy, slope steepness, and slope length exhibit non-linear behavior. When SLEMSA input parameters and results were compared to alternative methods of soil erosion assessment, such as drainage density and drainage texture, the model provided more spatially explicit information using 30 meter grid cells. Results of this

  13. 137Cs re-sampling as a method for soil erosion assessment in Alpine grasslands

    NASA Astrophysics Data System (ADS)

    Arata, Laura; Meusburger, Katrin; Bissig, Nicole; Mabit, Lionel; Alewell, Christine

    2014-05-01

    Over the past decades, radioactive fallout 137Cs has been used as a tracer to provide information on soil erosion and sedimentation rates. However, the method may produce relatively large uncertainties in Alpine grasslands. The latter difficulties are caused by a combination of (i) the heterogeneous distribution of atmospheric 137Cs Chernobyl fallout, (ii) the partly snow covered ground in Alpine areas during the fallout event in April 1986, which results in inhomogeneous 137Cs distribution during snow melt and (iii) uncertainties in finding undisturbed references sites in the geomorphological and anthropogenic highly active slopes of the Alps. To overcome these difficulties, our aim is to replace the classical 137Cs approach, where an undisturbed reference site is compared to erosional sites, with a re-sampling approach, where we re-sample sites which have already been measured for 137Cs inventories in the past. Thus, we use temporal instead of spatial reference. The study area is located in the Central Swiss Alps in the Urseren Valley. Potential erosional sites have been sampled in 2007 and re-sampled in 2012. Two different grassland types were investigated: hayfield (2 sites) and pasture without dwarf shrubs (3 sites). For each site, 4 to 9 sampling points have been defined, and at each point two soil samples have been collected. To reduce the random error, the two soil samples were bulked prior to gamma-analysis. 137Cs inventories of the two sampling years were calculated and used to assess recent soil erosion in the experimental sites. Our results show that within the 5 years measurable soil erosion and deposition processes have occurred within the sites, as indicated by the relevant difference between the 137Cs inventories of 2007 and 2012. 64% of the sites exhibit a decrease in 137Cs inventories, 20% of the sites an increase, and the remaining 16% no significant difference. In particular, hayfield sites have been affected by erosion processes, mostly due to

  14. Effects of olive mill wastes added to olive grove soils on erosion and soil properties

    NASA Astrophysics Data System (ADS)

    Lozano-García, Beatriz; Parras-Alcántara, Luis

    2014-05-01

    INTRODUCTION The increasing degradation of olive groves by effect of organic matter losses derived from intensive agricultural practices has promoted the use (by olive farmers) of olive mill wastes (olive leaves and alperujo) which contain large amounts of organic matter and are free of heavy metals and pathogenic microorganisms. In this work we compared the effects of these oil mill wastes on the decrease of soil erosion, also, we undertook the assessment of the organic carbon and nitrogen contents of soil, their distribution across the profile, the accumulation and Stratification ratios (SRs) of soil organic carbon (SOC) and total nitrogen (TN), and the C:N ratio, in Cambisols in Mediterranean olive groves treated with olive leaves and alperujo. MATERIALS AND METHODS The study area was a typical olive grove in southern Spain under conventional tillage (CT). Three plots were established. The first one was the control plot; the second one was treated with olive leaves (CTol) and the third one, with alperujo (CTa). 9 samples per plot were collected to examine the response of the soil 3 years after application of the wastes. Soil properties determined were: soil particle size, pH, bulk density, the available water capacity, SOC, TN and C:N ratio. SOC and N stock, expressed for a specific depth in Mg ha-1. Stratification ratios (SRs) (that can be used as an indicator of dynamic soil quality) for SOC and TN at three different depths were calculated. The erosion study was based on simulations of rain; that have been carried out in order to highlight differences in the phenomena of runoff and soil losses in the three plots considered. The effect of different treatments on soil properties was analyzed using a ANOVA, followed by an Anderson-Darling test. RESULTS Supplying the soil with the wastes significantly improved physical and chemical properties in the studied soils with respect to the control. C and N stocks increased, the SOC stock was 75.4 Mg ha-1 in CT, 91.5 Mg

  15. Viewpoint: Sustainability of pinon-juniper ecosystems - A unifying perspective of soil erosion thresholds

    USGS Publications Warehouse

    Davenport, D.W.; Breshears, D.D.; Wilcox, B.P.; Allen, C.D.

    1998-01-01

    Many pinon-juniper ecosystem in the western U.S. are subject to accelerated erosion while others are undergoing little or no erosion. Controversy has developed over whether invading or encroaching pinon and juniper species are inherently harmful to rangeland ecosystems. We developed a conceptual model of soil erosion in pinon-jumper ecosystems that is consistent with both sides of the controversy and suggests that the diverse perspectives on this issue arise from threshold effects operating under very different site conditions. Soil erosion rate can be viewed as a function of (1) site erosion potential (SEP), determined by climate, geomorphology and soil erodibility; and (2) ground cover. Site erosion potential and cove act synergistically to determine soil erosion rates, as evident even from simple USLE predictions of erosion. In pinon-juniper ecosystem with high SEP, the erosion rate is highly sensitive to ground cover and can cross a threshold so that erosion increases dramatically in response to a small decrease in cover. The sensitivity of erosion rate to SEP and cover can be visualized as a cusp catastrophe surface on which changes may occur rapidly and irreversibly. The mechanisms associated with a rapid shift from low to high erosion rate can be illustrated using percolation theory to incorporate spatial, temporal, and scale-dependent patterns of water storage capacity on a hillslope. Percolation theory demonstrates how hillslope runoff can undergo a threshold response to a minor change in storage capacity. Our conceptual model suggests that pinion and juniper contribute to accelerated erosion only under a limited range of site conditions which, however, may exist over large areas.

  16. Use of rare earth oxides and iron oxides as soil erosion tracers in water erosion experiments at hillslope scale

    NASA Astrophysics Data System (ADS)

    Guzmán, G.; Cañasveras, J. C.; Barrón, V.; Boulal, H.; Gómez, H.; Conde, E.; Fernández, M.; Gómez, J. A.

    2010-05-01

    The characteristics of the ideal soil erosion have been defined by several authors, for example by Zhang et al. (2001). Despite intensive research on erosion tracers in the last decades there is not a single tracer fulfilling all these characteristics. That is why research on different soil erosion tracers remains as an active field. Two desirable characteristics in erosion tracers are that they should be relatively inexpensive (to purchase and analyze) and that they should be determined with high accuracy in soil or sediment. The availability of multiple tracers is another of the key requirements. In this communication we present our preliminary results on the use of two different sets of erosion tracers. One set are iron oxides with different magnetic and optical properties (Fe3O4, α-Fe2O3 and FeOOH) analyzed by NIRS and magnetic susceptibility measurements. The other set consists of five rare earth oxides (La2O3, Pr6O11, Nd2O3, Sm2O3 and Gd2O3) analyzed using inductively coupled plasma mass spectrometry (ICP-MS). These two groups were studied under controlled and natural conditions, through several water erosion experiments, in field plots with different soil management, crops and scale. In one experiment these tracers were used to determine the source of sediment within sprinkle irrigated fields planted with cotton on shoulders. For this purpose, rainfall simulations were performed under controlled conditions at two scales, one with a portable rainfall simulator at small scale (0.81m2) and with the sprinkler irrigation system in the whole cotton field (2450 m2). Furrows were tagged with both groups of tracers, keeping shoulders untagged (where cotton was planted). Soil samples before and after the rainfall simulations were collected as well as sediment samples. In another experiment four olive orchard plots (330 m2) with different soil managements (cover crop and conventional tillage) were also tagged with the two groups of tracers. Soil samples were taken at

  17. Regional scale soil thickness prediction using digital terrain modeling and seismic data: application to erosion hazard mapping.

    NASA Astrophysics Data System (ADS)

    Rochat, A.; Grandjean, G.; Cerdan, O.; Samyn, K.

    2012-04-01

    Empirical laws derived from terrain parameters - such as DTM - and calibrated with in-situ borehole data are widely used for mapping soil thickness at regional scale. But with this approach, economical and practical constrains due to drilling requires to work on limited area (typically a few ten km2). Yet, seismic methods using surface waves, recently used for subsurface issue, showed a great interest for measuring soil thickness along profiles or in 3D (parcel mapping) which is more convenient for spacializing using empirical law calibration. Thus, to accurately map soil thickness over a 400km2 large area, we suggest to match measurement provided by SASW method (spectral analysis of surface waves) with an empirical law derived from terrain attributes. For this study, S-waves velocity has been measured along 10 profiles and after calibration with penetrometrics sounding, the value Vs=300 m/s was considered as a threshold between fertile soil (loess) and consolidated material (clay) leading to define the soil thickness. Comparison between measured soil thickness and the empirical index related to soil depth has shown significant results (R2=0.58). After index calibration, soil thickness was mapped over the catchment basin using a regression law between soil depth index and measured thickness. Finally, the French soil databank (BSS®) was used for the map validation: loess depths reported by geotechnical interpretation (drilling and sounding from BSS®) fit closely to depths predicted by the thickness map. The test zone was located within the Cailly Aubette-Robec catchment area, in the Northern part of France. The region has the particularity to be severely affected by erosion processes with dramatic farming issues. So, to valorize this soil thickness mapping methodology, results were exploited in term of erosion hazard characterization by coupling the thickness map with a soil loss rate map (in t/ha/year), leading to provide temporal information about erosion

  18. Soil erosion and significance for carbon fluxes in a mountainous Mediterranean-climate watershed.

    PubMed

    Smith, S V; Bullock, S H; Hinojosa-Corona, A; Franco-Vizcaíno, E; Escoto-Rodríguez, M; Kretzschmar, T G; Farfán, L M; Salazar-Ceseña, J M

    2007-07-01

    In topographically complex terrains, downslope movement of soil organic carbon (OC) can influence local carbon balance. The primary purpose of the present analysis is to compare the magnitude of OC displacement by erosion with ecosystem metabolism in such a complex terrain. Does erosion matter in this ecosystem carbon balance? We have used the Revised Universal Soil Loss Equation (RUSLE) erosion model to estimate lateral fluxes of OC in a watershed in northwestern Mexico. The watershed (4900 km2) has an average slope of 10 degrees +/- 9 degrees (mean +/- SD); 45% is >10 degrees, and 3% is >30 degrees. Land cover is primarily shrublands (69%) and agricultural lands (22%). Estimated bulk soil erosion averages 1350 Mg x km(-2) x yr(-1). We estimate that there is insignificant erosion on slopes < 2 degrees and that 20% of the area can be considered depositional. Estimated OC erosion rates are 10 Mg x km(-2) x yr(-1) for areas steeper than 2 degrees. Over the entire area, erosion is approximately 50% higher on shrublands than on agricultural lands, but within slope classes, erosion rates are more rapid on agricultural areas. For the whole system, estimated OC erosion is approximately 2% of net primary production (NPP), increasing in high-slope areas to approximately 3% of NPP. Deposition of eroded OC in low-slope areas is approximately 10% of low-slope NPP. Soil OC movement from erosional slopes to alluvial fans alters the mosaic of OC metabolism and storage across the landscape. PMID:17708215

  19. Quantifying and modeling soil erosion and sediment export from construction sites in southern California

    NASA Astrophysics Data System (ADS)

    Wernet, A. K.; Beighley, R. E.

    2006-12-01

    Soil erosion is a power process that continuously alters the Earth's landscape. Human activities, such as construction and agricultural practices, and natural events, such as forest fires and landslides, disturb the landscape and intensify erosion processes leading to sudden increases in runoff sediment concentrations and degraded stream water quality. Understanding soil erosion and sediment transport processes is of great importance to researchers and practicing engineers, who routinely use models to predict soil erosion and sediment movement for varied land use and climate change scenarios. However, existing erosion models are limited in their applicability to constructions sites which have highly variable soil conditions (density, moisture, surface roughness, and best management practices) that change often in both space and time. The goal of this research is to improve the understanding, predictive capabilities and integration of treatment methodologies for controlling soil erosion and sediment export from construction sites. This research combines modeling with field monitoring and laboratory experiments to quantify: (a) spatial and temporal distribution of soil conditions on construction sites, (b) soil erosion due to event rainfall, and (c) potential offsite discharge of sediment with and without treatment practices. Field sites in southern California were selected to monitor the effects of common construction activities (ex., cut/fill, grading, foundations, roads) on soil conditions and sediment discharge. Laboratory experiments were performed in the Soil Erosion Research Laboratory (SERL), part of the Civil and Environmental Engineering department at San Diego State University, to quantify the impact of individual factors leading to sediment export. SERL experiments utilize a 3-m by 10-m tilting soil bed with soil depths up to 1 m, slopes ranging from 0 to 50 percent, and rainfall rates up to 150 mm/hr (6 in/hr). Preliminary modeling, field and laboratory

  20. LandSoil model application for erosion management in sustainable agricultural landscapes

    NASA Astrophysics Data System (ADS)

    Smetanova, Anna; Follain, Stéphane; Raclot, Damien; Le Bissonnais, Yves

    2016-04-01

    Soil erosion and land degradation can lead to irreversible changes and landscape degradation. In order to achieve the sustainability of agricultural landscapes, the land use scenarios might be developed and tested for their erosion mitigation effects. Despite the importance of the long-term scenarios (which are complicated by predictability of climate change in a small scale, its effect on change in soil properties and crops, and the societal behaviour of individual players), the management decision have to be applied already now. Therefore the short-term and medium term scenarios to achieve the most effective soil management and the least soil erosion footprint are necessary to develop. With increasing importance of individual large erosion events, the event-based models, considering soil properties and landscape structures appears to be suitable. The LandSoil model (Ciampalini et al., 2012) - a landscape evolution model operating at the field/small catchment scale, have been applied in order to analyse the effect of different soil erosion mitigation and connectivity management practices in two different Mediterranean catchments. In the soil erosion scenarios the proposed measures targeted soil erosion on field or on catchment scale, and the effect of different extreme events on soil redistribution was evaluated under different spatial designs. Anna Smetanová has received the support of the AgreenSkills fellowship (under grant agreement n°267196). R. Ciampalini, S. Follain, Y. Le Bissonnais, LandSoil: A model for analysing the impact of erosion on agricultural landscape evolution, Geomorphology, 175-176, 2012, 25-37.

  1. Quantifying the erosion effect on current carbon budget of European agricultural soils at high spatial resolution.

    PubMed

    Lugato, Emanuele; Paustian, Keith; Panagos, Panos; Jones, Arwyn; Borrelli, Pasquale

    2016-05-01

    The idea of offsetting anthropogenic CO2 emissions by increasing global soil organic carbon (SOC), as recently proposed by French authorities ahead of COP21 in the 'four per mil' initiative, is notable. However, a high uncertainty still exits on land C balance components. In particular, the role of erosion in the global C cycle is not totally disentangled, leading to disagreement whether this process induces lands to be a source or sink of CO2. To investigate this issue, we coupled soil erosion into a biogeochemistry model, running at 1 km(2) resolution across the agricultural soils of the European Union (EU). Based on data-driven assumptions, the simulation took into account also soil deposition within grid cells and the potential C export to riverine systems, in a way to be conservative in a mass balance. We estimated that 143 of 187 Mha have C erosion rates <0.05 Mg C ha(-1) yr(-1), although some hot-spot areas showed eroded SOC >0.45 Mg C ha(-1) yr(-1). In comparison with a baseline without erosion, the model suggested an erosion-induced sink of atmospheric C consistent with previous empirical-based studies. Integrating all C fluxes for the EU agricultural soils, we estimated a net C loss or gain of -2.28 and +0.79 Tg yr(-1) of CO2 eq, respectively, depending on the value for the short-term enhancement of soil C mineralization due to soil disruption and displacement/transport with erosion. We concluded that erosion fluxes were in the same order of current carbon gains from improved management. Even if erosion could potentially induce a sink for atmospheric CO2, strong agricultural policies are needed to prevent or reduce soil erosion, in order to maintain soil health and productivity. PMID:26679897

  2. Soil depth mapping using seismic surface waves for the assessment of soil vulnerability to erosion.

    NASA Astrophysics Data System (ADS)

    Samyn, K.; Cerdan, O.; Grandjean, G.; Bitri, A.; Bernardie, S.; Ouvry, J. F.

    2009-04-01

    The purposes of the multidisciplinary DIGISOIL project are the integration and improvement of in situ and proximal technologies for the assessment of soil properties and soil degradation indicators. Foreseen developments concern sensor technologies, data processing and their integration to applications of (digital) soil mapping (DSM). Among available techniques, the seismic one is, in this study, particularly tested for characterising soil vulnerability to erosion. The spectral analysis of surface waves (SASW) method is an in situ seismic technique used for evaluation of the stiffnesses (G) and associated depth in layered systems. The method is based on the propagation of mechanically induced Rayleigh waves. By striking the ground surface with a hammer, seismic waves are generated, including surface Rayleigh waves. During their propagation, they are recorded by seismic receivers (geophone sensors) regularly spaced along a profile to produce a seismogram. The particularity of Rayleigh waves lies in the dependence of their velocity with frequency, a phenomenon called dispersion. A profile of Rayleigh wave velocity versus frequency, i.e., the dispersion curve, is calculated from each recorded seismogram before to be inverted to obtain the vertical profile of shear waves velocity. Then, the soil stiffness can easily be calculated from the shear velocity if the material density is estimated, and the soil stiffness as a function of depth can be obtained. This last information can be a good indicator to identify the soil bedrock limit. From a geometrical point of view, a SASW system adapted to soil characterisation is proposed in the DIGISOIL project. This system was tested for the digital mapping of the depth of loamy material in a catchment of the European loess belt. Parametric penetrometric studies are also conducted for the purpose of verifying the accuracy of the procedure and evaluating its limitations. The depth to bedrock determined by this procedure can then be

  3. Soil erosion and causative factors at Vandenberg Air Force Base, California

    NASA Technical Reports Server (NTRS)

    Butterworth, Joel B.

    1988-01-01

    Areas of significant soil erosion and unvegetated road cuts were identified and mapped for Vandenberg Air Force Base. One hundred forty-two eroded areas (most greater than 1.2 ha) and 51 road cuts were identified from recent color infrared aerial photography and ground truthed to determine the severity and causes of erosion. Comparison of the present eroded condition of soils (as shown in the 1986 photography) with that in historical aerial photography indicates that most erosion on the base took place prior to 1928. However, at several sites accelerated rates of erosion and sedimentation may be occurring as soils and parent materials are eroded vertically. The most conspicuous erosion is in the northern part of the base, where severe gully, sheet, and mass movement erosion have occurred in soils and in various sedimentary rocks. Past cultivation practices, compounded by highly erodible soils prone to subsurface piping, are probably the main causes. Improper range management practices following cultivation may have also increased runoff and erosion. Aerial photography from 1986 shows that no appreciable headward erosion or gully sidewall collapse have occurred in this area since 1928.

  4. Finite element evaluation of erosion/corrosion affected reducing elbow

    SciTech Connect

    Basavaraju, C.

    1996-12-01

    Erosion/corrosion is a primary source for wall thinning or degradation of carbon steel piping systems in service. A number of piping failures in the power industry have been attributed to erosion/corrosion. Piping elbow is one of such susceptible components for erosion/corrosion because of increased flow turbulence due to its geometry. In this paper, the acceptability of a 12 in. x 8 in. reducing elbow in RHR service water pump discharge piping, which experienced significant degradation due to wall thinning in localized areas, was evaluated using finite element analysis methodology. Since the simplified methods showed very small margin and recommended replacement of the elbow, a detailed 3-D finite element model was built using shell elements and analyzed for internal pressure and moment loadings. The finite element analysis incorporated the U.T. measured wall thickness data at various spots that experienced wall thinning. The results showed that the elbow is acceptable as-is until the next fuel cycle. FEA, though cumbersome, and time consuming is a valuable analytical tool in making critical decisions with regard to component replacement of border line situation cases, eliminating some conservatism while not compromising the safety.

  5. Plutonium in Soils from Northeast China and Its Potential Application for Evaluation of Soil Erosion

    PubMed Central

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin; Pan, Shaoming

    2013-01-01

    Surface and soil core samples from northeast China were analyzed for Pu isotopes. The measured 240Pu/239Pu atomic ratios and 239 + 240Pu/137Cs activity ratios revealed that the global fallout is the dominant source of Pu and 137Cs at these sites. Migration behavior of Pu varying with land type and human activities resulted in different distribution of Pu in surface soils. A sub-surface maximum followed by exponential decline of 239 + 240Pu concentrations was observed in an undisturbed soil core, with a total 239 + 240Pu inventory of 86.9 Bq/m2 and more than 85% accumulated in 0 ~ 20 cm layers. While only half inventory of Pu was obtained in another soil core and no sub-surface maximum value occurred. Erosion of topsoil in the site should be the most possible reason for the significantly lower Pu inventory, which is also supported by the reported 137Cs profiles. These results demonstrated that Pu could be applied as an ideal substitute of 137Cs for soil erosion study in the future. PMID:24336360

  6. Antecedent moisture content and soil texture effects on infiltration and erosion

    NASA Astrophysics Data System (ADS)

    Mamedov, A. I.; Huang, C.; Levy, G. J.

    2006-12-01

    Water infiltration, seal formation, runoff and erosion depend on the soil's inherent properties and surface conditions. Most erosion models consider only soil inherent properties (mainly texture) in assessing infiltration and erosion without consideration of spatial and temporary variation in the surface condition, particularly the antecedent moisture content. We studied the interaction of two different surface conditions, i.e. antecedent moisture content (AMC) and aging (timing after wetting) on infiltration (IR), seal formation (runoff generation) and erosion in four soils varying from loam to clay. Soil samples were packed in erosion box and wetted with different amounts of water (0, 1, 2, 3, 4, 6, 8, or 16 mm) to obtain a wide moisture range (i.e., pF 0-6.2, or from air dry to full saturation). The boxes were put in plastic bags and allowed to age for 0.01, 1, 3, or 7 days. Then the soil in the erosion box exposed to 60 mm of rain. At no aging final IR of soils did not change significantly, but runoff volume (a measure for seal development) and soil loss increased with an increase in AMC mainly because of aggregate breakdown. For any given aging, the highest IR and smallest runoff volume and soil loss were obtained at the intermediate AMC levels (pF 2.4-4.2, between wilting point and field capacity). For instance, in the clay soil to which 3 mm of water (pF~2.7) was added, as aging increased from one to seven days, final IR increased from 5.3 to 7.9 mm h-1, while runoff and soil loss decreased from 34 mm to 22 mm, and from 630 to 360 g m2 respectively. At this AMC range, increasing aging time resulted in up to 40% increase in IR and decrease in runoff or soil loss. This tendency significantly more pronounced for clay soils because water-filled pores in the clay fabric were considered active in the stabilization process and the development of cohesive bonds between and within particles during the aging period. The results of this study are important for soil

  7. A framework for risk assessment on soil erosion by water using an integrated and systematic approach

    NASA Astrophysics Data System (ADS)

    Wu, Qiang; Wang, Mingyu

    2007-04-01

    SummaryA new approach for establishment of an analytical risk assessment model to evaluate the risk index for soil erosion by water is proposed, in which the remote sensing, GIS, the analytical hierarchy process (AHP), and modeling techniques are integrated through investigation of soil erosion by water in a joining area that partially covers the Shanxi province, Shaanxi province, and Inner Mongolia Autonomous Region of China. Based on field survey and information analyses, pertinent factors for soil erosion by water in this region are assessed and nine dominating factors are identified. The considered dominating factors include the soil type, rainstorm intensity, landform accounting for physiognomy type, ravine density, and land slope, vegetation coverage, mining area, level of water and soil conservation, and type of land uses. The GIS thematic layers of degrees of risk on soil erosion for those dominating factors are constructed. The weight of each thematic layer is determined through the AHP technique. This model is then applied in predicting development of soil erosion at a typical scenario for this study area. A brief discussion on construction and application of this model is presented. It is demonstrated that the presented methodology is practicable for establishing a risk assessment mode for soil erosion by water for an area of interest where pertinent information such as remote sensing data is available. A flowchart presenting a general procedure for implementation of the proposed approach is also included.

  8. Spatial scale effects on the effectiveness of organic mulches in reducing soil erosion by water

    NASA Astrophysics Data System (ADS)

    Smets, T.; Poesen, J.; Knapen, A.

    2008-07-01

    Experimental research revealed that mulching the soil surface is an effective soil conservation practice. However, reported effectiveness of mulch covers varies widely and there are indications that spatial measurement scale (i.e. plot length) explains part of this variability. The objective of this study is therefore to analyse the impacts of plot length at which field and laboratory experiments were conducted on the effectiveness of mulch covers in reducing soil loss by water erosion. In this review, 41 studies investigating the impacts of mulch cover on soil erosion by water are analysed (plot length ranges between 0.1 and 30.5 m). Calculated mulch effectiveness factors, i.e. b-values from the mulch factor equation, range between 0.0097 and 0.1320 and increase linearly with plot length for the reviewed experiments: b = 0.022 + 0.0017 * plot_length (m); R2 = 0.37; n = 41. However, care should be taken when using this relationship for extrapolations to longer plots. Furthermore, slope gradient, soil type and mulch type determine the variability of the effectiveness of mulch covers in reducing soil erosion rates by water. Depending on the dominant soil erosion process (i.e. splash, interrill, rill and interrill or rill erosion), these variables also partly control the effectiveness of a mulch cover in reducing soil erosion by water.

  9. Runoff and inter-rill soil erosion following wildfire and terracing in north-central Portugal

    NASA Astrophysics Data System (ADS)

    Martins, Martinho A. S.; Machado, Ana Isabel; Serpa, Dalila; Prats, Sergio; Faria, Silvia; Eufemia Varela, María; Keizer, Jan Jacob

    2013-04-01

    In Portugal, wildfires occur frequently and affect large areas, on average some 100.000 ha per year but in extreme years such as 2003 and 2005 over 300.000 ha. Wildfires can lead to considerable changes in geomorphologic and hydrological processes, as evidenced by the strong and sometimes extreme responses in post-fire runoff and erosion reported from various parts of the world, including Portugal. Besides wildfire itself, also post-fire forestry practices can strongly influence the hydrological and erosion response in recently burnt areas. In north-central Portugal, for example, rip ploughing in down-slope direction was found to be far more damaging in terms of soil loss than fire. Whilst rip ploughing in down-slope direction has now by and large been abandoned in the region, the construction of terraces in preparation of new tree and especially eucalypt plantations has become increasingly common. Although terraces are traditionally viewed as a technique for soil conservation, the authors have measured high splash erosion rates on recent terraces and have frequently observed small-scale erosion features and, on one occasion, gully formation over the full hill slope length. Runoff and sediment losses, however, have hardly ever been quantified for recently terraced plantations. In this study, we compared runoff and erosion, at the micro-plot scale, before and after terracing, during the first seven months after a wildfire and during the subsequent 17 months. This was done at two contrasting hill slopes, designated here as eucalypt and pine site. The former was, at the time of the wildfire, covered by eucalypt and then terraced and re-planted with eucalypt over its full extent; the latter was initially covered with pine and then partially terraced and planted with eucalypt and partially left to regenerate spontaneously. Total rainfall was rather similar for the pre- and post-terracing period (1205 and 1437 mm), in spite of their different, above-mentioned durations

  10. Extensive management of field margins enhances their potential for off-site soil erosion mitigation.

    PubMed

    Ali, Hamada E; Reineking, Björn

    2016-03-15

    Soil erosion is a widespread problem in agricultural landscapes, particularly in regions with strong rainfall events. Vegetated field margins can mitigate negative impacts of soil erosion off-site by trapping eroded material. Here we analyse how local management affects the trapping capacity of field margins in a monsoon region of South Korea, contrasting intensively and extensively managed field margins on both steep and shallow slopes. Prior to the beginning of monsoon season, we equipped a total of 12 sites representing three replicates for each of four different types of field margins ("intensive managed flat", "intensive managed steep", "extensive managed flat" and "extensive managed steep") with Astroturf mats. The mats (n = 15/site) were placed before, within and after the field margin. Sediment was collected after each rain event until the end of the monsoon season. The effect of management and slope on sediment trapping was analysed using linear mixed effects models, using as response variable either the sediment collected within the field margin or the difference in sediment collected after and before the field margin. There was no difference in the amount of sediment reaching the different field margin types. In contrast, extensively managed field margins showed a large reduction in collected sediment before and after the field margins. This effect was pronounced in steep field margins, and increased with the size of rainfall events. We conclude that a field margin management promoting a dense vegetation cover is a key to mitigating negative off-site effects of soil erosion in monsoon regions, particularly in field margins with steep slopes. PMID:26760443

  11. Internal erosion during soil pipe flow: Role in gully erosion and hillslope instability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many field observations have lead to speculation on the role of piping in embankment failures, landslides, and gully erosion. However, there has not been a consensus on the subsurface flow and erosion processes involved and inconsistent use of terms have exasperated the problem. One such piping proc...

  12. Application of the Water Erosion Prediction Project (WEPP) Model for Soil Erosion Estimation and Conservation Planning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Water Erosion Prediction Project (WEPP) model is a process-based, continuous- simulation, distributed parameter erosion simulation model for application to field-scale hillslope profiles and small watersheds. Developed over the past 25 years by the United States Department of Agriculture, it con...

  13. The role of forest stand density in controlling soil erosion: implications to sediment-related disasters in Japan.

    PubMed

    Razafindrabe, Bam H N; He, Bin; Inoue, Shoji; Ezaki, Tsugio; Shaw, Rajib

    2010-01-01

    The role of forest stand density in controlling soil erosion was investigated in Ehime Prefecture, Japan. The main objective was to compare soil erosion under different forest conditions including forest type, species composition, and stand density as influenced by thinning operations. Relative yield index (Ry) was used as an indicator of stand density to reflect the degree of management operations in the watershed. Eleven treatments were established based on the above forest conditions. Soil loss was collected in each of the 11 treatments after each rainfall event for a period of 1 year. The paper presents summary data on soil loss as affected by forest conditions and rainfall patterns. Findings showed that an appropriate forest management operation, which can be insured by stand density control, is needed to reduce soil loss. The present study plays an important role in clarifying technical processes related to soil erosion, while it helps linking these elements to current Japanese forestry issues and bringing new inputs to reducing sediment-related disasters in Japan. PMID:19105038

  14. Biological soil crusts reduce soil erosion in early successional subtropical forests in PR China

    NASA Astrophysics Data System (ADS)

    Seitz, Steffen; Goebes, Philipp; Käppeler, Kathrin; Nebel, Martin; Webber, Carla; Scholten, Thomas

    2016-04-01

    Biological soil crusts (BSCs) have major influences on terrestrial ecosystems and play significant functional roles in soil systems, such as accelerating soil formation, changing water flows or enhancing soil stability. By that, they have the potential to protect soil surfaces against erosive forces by wind or water. However, the effect of BSCs on erosion processes is rarely mentioned in literature and most of the work done focused on arid and semi-arid environments. Furthermore, compared to the structure and function of BSCs, less attention was paid to their temporal and topographical distribution. This study aims to investigate the influence of BSCs on initial soil erosion, and their topographical development over time in initial subtropical forest ecosystems. Therefore, measurements have been conducted within a biodiversity and ecosystem functioning experiment (BEF China) near Xingangshan, Jiangxi Province, PR China. Interrill erosion was measured on 220 microscale run-off plots (ROPs, 0.4 m × 0.4 m) and the occurrence, distribution and development of BSCs within the measuring setup were recorded. BSC cover in each ROP was determined photogrammetrically in four time steps (autumn 2011, summer 2012, summer 2013 and summer 2014). BSC species were identified by morphological characteristics and classified to higher taxonomic levels. Higher BSC cover led to reduced sediment discharge and runoff volume due to its protection against splash energy, the adherence of soil particles and enhanced infiltration. Canopy ground cover and leaf area index had a positive effect on the development of BSC cover at this initial stage of the forest ecosystem. Moreover, BSC cover decreased with increasing slope, as we presume that developing BSCs are washed away more easily at steep gradients. Elevation and aspect did not show an influence. BSCs in this study were moss-dominated and 26 different moos species were found. Mean BSC cover on ROPs was 14 % in the 3rd year of the tree

  15. Soil coverage evolution and wind erosion risk on summer crops under contrasting tillage systems

    NASA Astrophysics Data System (ADS)

    Mendez, Mariano J.; Buschiazzo, Daniel E.

    2015-03-01

    The effectiveness of wind erosion control by soil surface conditions and crop and weed canopy has been well studied in wind tunnel experiments. The aim of this study is to assess the combined effects of these variables under field conditions. Soil surface conditions, crop and weed coverage, plant residue, and non-erodible aggregates (NEA) were measured in the field between the fallow start and the growth period of sunflower (Helianthus annuus) and corn (Zea mays). Both crops were planted on a sandy-loam Entic Haplustoll with conventional-(CT), vertical-(VT) and no-till (NT) tillage systems. Wind erosion was estimated by means of the spreadsheet version the Revised Wind Erosion Equation and the soil coverage was measured each 15 days. Results indicated that wind erosion was mostly negligible in NT, exceeding the tolerable levels (estimated between 300 and 1400 kg ha-1 year-1 by Verheijen et al. (2009)) only in an year with high climatic erosivity. Wind erosion exceeded the tolerable levels in most cases in CT and VT, reaching values of 17,400 kg ha-1. Wind erosion was 2-10 times higher after planting of both crops than during fallows. During the fallows, the soil was mostly well covered with plant residues and NEA in CT and VT and with residues and weeds in NT. High wind erosion amounts occurring 30 days after planting in all tillage systems were produced by the destruction of coarse aggregates and the burying of plant residues during planting operations and rains. Differences in soil protection after planting were given by residues of previous crops and growing weeds. The growth of weeds 2-4 weeks after crop planting contributed to reduce wind erosion without impacting in crops yields. An accurate weeds management in semiarid lands can contribute significantly to control wind erosion. More field studies are needed in order to develop management strategies to reduce wind erosion.

  16. Soil roughness: comparing old and new methods and application in a soil erosion model

    NASA Astrophysics Data System (ADS)

    Thomsen, Line; Stolte, Jannes; Baartman, Jantiene; Starkloff, Torsten

    2014-05-01

    This study compared five methods for measuring soil surface roughness, two contact methods: pinboard and roller chain, and three non-contact methods: laser scanner, stereophotogrammetry and the "Kinect". The latter is a 3D depth sensor originally developed for gaming consoles, which recently was proved to be applicable for high-resolution DEM. Roughness was in this study defined as irregularities in the surface related to soil type and tillage practice. The index random roughness (RR), calculated as the standard deviation of a number of elevation recordings, was used for comparison. The methods were compared in terms of accuracy, precision, resolution, ease of use and price. The obtained average random roughness values were used as input in a physical-based spatially-distributed erosion model, LISEM. Results showed that the various methods have different pros and cons and since the methods use different principles to obtain roughness data, they are prone to different errors. The "Kinect" proved to be a useful sensor, both in terms of obtainable resolution (~90 000 measurements per m2) as well as costs and ease of use. The erosion model was relatively sensitive to the roughness input data, with a 20% and 40% increase in RR yielding approximately 20% and 40% decrease in hydrograph peak discharge [l/s], respectively. Interestingly, roughness data obtained with different methods (laser scanner versus "Kinect"), which in statistical terms were not significantly different from each other did cause a ~50% change in hydrograph peak, indicating that the model sensitivity is not adjusted for the obtainable accuracy of measured roughness data. For improved model performance it is suggested to determine the required accuracy and precision as well as the preferred method of measured random roughness data when used as input to an erosion model like LISEM. Key words: soil surface roughness, random roughness, erosion modelling, LISEM, the Kinect, data accuracy

  17. A Comparison of Splash Erosion Behavior between Wettable and Water Repellent 'Soil' Particles

    NASA Astrophysics Data System (ADS)

    Ahn, S.; Hamlett, C. A.; Doerr, S.; Bryant, R.; Shirtcliffe, N.; McHale, G.; Newton, M.

    2011-12-01

    Wildfires remove vegetation and litter cover and expose soil surfaces to particle detachment by rain splash. This can serve as an agent of initial soil modification and erosion in the post-fire period. Splash behavior is mainly determined by the kinetic energy delivered by impacting water drops (erosivity), and the detachability (erodibility) of surface particles, affected by their size, aggregate stability and shear strength. Soil detachability may also be affected by water repellency (hydrophobicity). This soil characteristic is influenced by wildfire and may affect splash behavior by reducing capillary forces between particles. Previous work on splash behavior using cumulative drop impact reported larger ejection droplets and lower and shorter trajectories of ejections for water repellent soil compared with wettable soil (Terry and Shakesby 1993). A water film generated by delayed infiltration on water repellent soil was suggested to account for the difference. This study compares the trajectories of ejected wettable and hydrophobic model soil particles from single water drop impacts in order to isolate the effect of soil particle wettability on splash erosion behavior. Acid-washed (wettable) and hydrophobized (water repellent) glass beads used as model soil particles were held in an array within a squat cylinder of 1.5 cm diameter in the centre of a 20 cm diameter disk covered with a viscous adhesive film. A distilled water drop (20μL) was released 40 cm above the centre of the array and the resultant impact was recorded at 976 frames per second using a high speed video camera. The populations of, and distances travelled by, the particles were measured for three arrays of bead sizes within the range (180-400 μm). Three to five replications were made for each test. The trajectory of each ejected particle was traced on video frames and corrected for the actual distance and direction of travel measured from the adhesive film. The initial velocity and ejecting

  18. Soil Erosion: Quiet Crisis in the World Economy. Worldwatch Paper 60.

    ERIC Educational Resources Information Center

    Brown, Lester R.; Wolf, Edward C.

    Although soil erosion is a natural process, it has increased to the point where it far exceeds the natural formation of new soil. However, with only occasional exceptions, national agricultural and population policies have failed to take soil depletion into account. Projections of world food production always incorporate estimates of future…

  19. Development of a coupled soil erosion and large-scale hydrology modeling system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of frozen soil on soil erosion is becoming increasingly important for sustainable management of soil resources, especially in regions where agricultural land use is dominant. A newly developed coupled modeling system that integrates the Variable Infiltration Capacity (VIC) model and the p...

  20. Predicting soil erosion and deposition effects on plant establishment: A key to increasing restoration success

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion and deposition can result in significant modification of the soil profile, including changes in soil surface texture and structure. A series of field studies and modeling exercises are currently being completed at the USDA-ARS Jornada Experimental Range, located in the northern Chihuahu...

  1. Polyacrylamide Molecular Weight and Phosphogypsum Effects on Infiltration and Erosion in Semi-Arid Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seal formation at the surface of semi-arid soils during rainstorms reduces soil infiltration rate (IR) and causes runoff and erosion. Surface application of dry anionic polyacrylamide (PAM) with high molecular weight (MW) has been found to be effective in stabilizing soil aggregates, and decreasing ...

  2. Polyacrylamide molecular weight and phosphogypsum effects on infiltration and erosion in semi-arid soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seal formation at the surface of semi-arid soils during rainstorms reduces soil infiltration rate (IR) and causes runoff and erosion. Surface application of dry anionic polyacrylamide (PAM) with high molecular weight (MW) has been found to be effective in stabilizing soil aggregates, and decreasing ...

  3. PM2.5 and PM10 Emission from Agricultural Soils by Wind Erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil tillage and wind erosion are a major source of particulate matter less than 2.5 and 10 µm (PM2.5 and PM10) emission from cultivated soil. Fifteen cultivated soils collected from 5 states were tested as crushed (<2.0 mm) and uncrushed (natural aggregation) at 8, 10, and 13 m s-1 wind velocity in...

  4. Sediment composition for the assessment of water erosion and nonpoint source pollution in natural and fire-affected landscapes.

    PubMed

    Carkovic, Athena B; Pastén, Pablo A; Bonilla, Carlos A

    2015-04-15

    Water erosion is a leading cause of soil degradation and a major nonpoint source pollution problem. Many efforts have been undertaken to estimate the amount and size distribution of the sediment leaving the field. Multi-size class water erosion models subdivide eroded soil into different sizes and estimate the aggregate's composition based on empirical equations derived from agricultural soils. The objective of this study was to evaluate these equations on soil samples collected from natural landscapes (uncultivated) and fire-affected soils. Chemical, physical, and soil fractions and aggregate composition analyses were performed on samples collected in the Chilean Patagonia and later compared with the equations' estimates. The results showed that the empirical equations were not suitable for predicting the sediment fractions. Fine particles, including primary clay, primary silt, and small aggregates (<53 μm) were over-estimated, and large aggregates (>53 μm) and primary sand were under-estimated. The uncultivated and fire-affected soils showed a reduced fraction of fine particles in the sediment, as clay and silt were mostly in the form of large aggregates. Thus, a new set of equations was developed for these soils, where small aggregates were defined as particles with sizes between 53 μm and 250 μm and large aggregates as particles>250 μm. With r(2) values between 0.47 and 0.98, the new equations provided better estimates for primary sand and large aggregates. The aggregate's composition was also well predicted, especially the silt and clay fractions in the large aggregates from uncultivated soils (r(2)=0.63 and 0.83, respectively) and the fractions of silt in the small aggregates (r(2)=0.84) and clay in the large aggregates (r(2)=0.78) from fire-affected soils. Overall, these new equations proved to be better predictors for the sediment and aggregate's composition in uncultivated and fire-affected soils, and they reduce the error when estimating soil loss in

  5. USLE-Based Assessment of Soil Erosion by Water in the Nyabarongo River Catchment, Rwanda.

    PubMed

    Karamage, Fidele; Zhang, Chi; Kayiranga, Alphonse; Shao, Hua; Fang, Xia; Ndayisaba, Felix; Nahayo, Lamek; Mupenzi, Christophe; Tian, Guangjin

    2016-01-01

    Soil erosion has become a serious problem in recent decades due to unhalted trends of unsustainable land use practices. Assessment of soil erosion is a prominent tool in planning and conservation of soil and water resource ecosystems. The Universal Soil Loss Equation (USLE) was applied to Nyabarongo River Catchment that drains about 8413.75 km² (33%) of the total Rwanda coverage and a small part of the Southern Uganda (about 64.50 km²) using Geographic Information Systems (GIS) and Remote Sensing technologies. The estimated total annual actual soil loss was approximately estimated at 409 million tons with a mean erosion rate of 490 t·ha(-1)·y(-1) (i.e., 32.67 mm·y(-1)). The cropland that occupied 74.85% of the total catchment presented a mean erosion rate of 618 t·ha(-1)·y(-1) (i.e., 41.20 mm·y(-1)) and was responsible for 95.8% of total annual soil loss. Emergency soil erosion control is required with a priority accorded to cropland area of 173,244 ha, which is extremely exposed to actual soil erosion rate of 2222 t·ha(-1)·y(-1) (i.e., 148.13 mm·y(-1)) and contributed to 96.2% of the total extreme soil loss in the catchment. According to this study, terracing cultivation method could reduce the current erosion rate in cropland areas by about 78%. Therefore, the present study suggests the catchment management by constructing check dams, terracing, agroforestry and reforestation of highly exposed areas as suitable measures for erosion and water pollution control within the Nyabarongo River Catchment and in other regions facing the same problems. PMID:27556474

  6. USLE-Based Assessment of Soil Erosion by Water in the Nyabarongo River Catchment, Rwanda

    PubMed Central

    Karamage, Fidele; Zhang, Chi; Kayiranga, Alphonse; Shao, Hua; Fang, Xia; Ndayisaba, Felix; Nahayo, Lamek; Mupenzi, Christophe; Tian, Guangjin

    2016-01-01

    Soil erosion has become a serious problem in recent decades due to unhalted trends of unsustainable land use practices. Assessment of soil erosion is a prominent tool in planning and conservation of soil and water resource ecosystems. The Universal Soil Loss Equation (USLE) was applied to Nyabarongo River Catchment that drains about 8413.75 km2 (33%) of the total Rwanda coverage and a small part of the Southern Uganda (about 64.50 km2) using Geographic Information Systems (GIS) and Remote Sensing technologies. The estimated total annual actual soil loss was approximately estimated at 409 million tons with a mean erosion rate of 490 t·ha−1·y−1 (i.e., 32.67 mm·y−1). The cropland that occupied 74.85% of the total catchment presented a mean erosion rate of 618 t·ha−1·y−1 (i.e., 41.20 mm·y−1) and was responsible for 95.8% of total annual soil loss. Emergency soil erosion control is required with a priority accorded to cropland area of 173,244 ha, which is extremely exposed to actual soil erosion rate of 2222 t·ha−1·y−1 (i.e., 148.13 mm·y−1) and contributed to 96.2% of the total extreme soil loss in the catchment. According to this study, terracing cultivation method could reduce the current erosion rate in cropland areas by about 78%. Therefore, the present study suggests the catchment management by constructing check dams, terracing, agroforestry and reforestation of highly exposed areas as suitable measures for erosion and water pollution control within the Nyabarongo River Catchment and in other regions facing the same problems. PMID:27556474

  7. Advances in soil erosion modelling through remote sensing data availability at European scale

    NASA Astrophysics Data System (ADS)

    Panagos, Panos; Karydas, Christos; Borrelli, Pasqualle; Ballabio, Cristiano; Meusburger, Katrin

    2014-08-01

    Under the European Union's Thematic Strategy for Soil Protection, the European Commission's Directorate-General for the Environment (DG Environment) has identified the mitigation of soil losses by erosion as a priority area. Policy makers call for an overall assessment of soil erosion in their geographical area of interest. They have asked that risk areas for soil erosion be mapped under present land use and climate conditions, and that appropriate measures be taken to control erosion within the legal and social context of natural resource management. Remote sensing data help to better assessment of factors that control erosion, such as vegetation coverage, slope length and slope angle. In this context, the data availability of remote sensing data during the past decade facilitates the more precise estimation of soil erosion risk. Following the principles of the Universal Soil Loss Equation (USLE), various options to calculate vegetative cover management (C-factor) have been investigated. The use of the CORINE Land Cover dataset in combination with lookup table values taken from the literature is presented as an option that has the advantage of a coherent input dataset but with the drawback of static input. Recent developments in the Copernicus programme have made detailed datasets available on land cover, leaf area index and base soil characteristics. These dynamic datasets allow for seasonal estimates of vegetation coverage, and their application in the G2 soil erosion model which represents a recent approach to the seasonal monitoring of soil erosion. The use of phenological datasets and the LUCAS land use/cover survey are proposed as auxiliary information in the selection of the best methodology.

  8. Keeping soil in the field - runoff and erosion management in asparagus crops

    NASA Astrophysics Data System (ADS)

    Niziolomski, Joanna; Simmons, Robert; Rickson, Jane; Hann, Mike

    2016-04-01

    Row crop production (including potatoes, onions, carrots, asparagus, bulbs and lettuce) is regarded as one of the most erosive agricultural cropping systems. This is a result of the many practices involved that increase erosion risk including: fine seedbed preparation, a typically short growing season where adequate ground cover protects the soil, permanent bare soil areas between crops, and often intensive harvesting methods that can damage soil structure and result in soil compaction. Sustained exposure of bare soil coupled with onsite compaction on slightly sloping land results in soil and water issues in asparagus production. Asparagus production is a growing British industry covering > 2000 ha and is worth approximately £30 million yr‑1. However, no tried and tested erosion control measurements currently exist to manage associated problems. Research has recently been undertaken investigating the effectiveness of erosion control measures suitable for asparagus production systems. These consisted of surface applied wheat straw mulch and shallow soil disturbance (< 350 mm) using several tine configurations: a currently adopted winged tine, a narrow with two shallow leading tines, and a modified para-plough. These treatments were tested individually and in combination (straw mulch with each shallow soil disturbance tine configuration) using triplicated field plots situated on a working asparagus farm in Herefordshire, UK. Testing was conducted between May and November 2013. Rainfall-event based runoff and erosion measurements were taken including; runoff volume, runoff rate and total soil loss. Runoff and soil erosion was observed from all treatments. However, the surface application of straw mulch alone out performed each shallow soil disturbance practice. This suggests that runoff and erosion from asparagus production can be reduced using the simple surface application of straw.

  9. Extreme soil erosion rates in citrus slope plantations and control strategies. A literature review

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Ángel González Peñaloza, Félix; Pereira, Paulo; Reyes Ruiz Gallardo, José; García Orenes, Fuensanta; Burguet, María

    2013-04-01

    Soil Erosion is a natural process that shapes the Earth. Due to the impact of agriculture, soil erosion rates increase, landforms show gullies and rills, and soils are depleted. In the Mediterranean, wheat, olive and vineyards were the main agriculture products, but new plantations are being found in sloping terrain due to the drip-irrigation. This new strategy results in the removal of the traditional terraces in order to make suitable for mechanization the agriculture plantation. Citrus is a clear example of the impact of the new chemical agriculture with a high investment in herbicides, pesticides, mechanisation, land levelling and drip computer controlled irrigation systems. The new plantation of citrus orchards is found in the Mediterranean, but also in California, Florida, China and Brazil. Chile, Argentina, and South Africa are other producers that are moving to an industrial production of citrus. This paper shows how the citrus plantations are found as one of the most aggressive plantation due to the increase in soil erosion, and how we can apply successful control strategies. The research into the high erosion rates of citrus orchard built on the slopes are mainly found in China (Wu et al., 1997; Xu et al., 2010; Wang et al., 2011; Wu et al., 2011; Liu et al., 2011; Lü et al., 2011; Xu et al., 2012) and in the Mediterranean (Cerdà and Jurgensen, 2008; 2009; Cerdà et al., 2009a; 2009b; Cerdà et al., 2011; 2012) Most of the research done devoted to the measurements of the soil losses but also some research is done related to the soil properties (Lu et al., 1997; Lü et al., 2012; Xu et al., 2012) and the impact of cover crops to reduce the soil losses (Lavigne et al., 2012; Le Bellec et al., 2012) and the use of residues such as dried citrus peel in order to reduce the soil losses. There are 116 million tonnes of citrus produced yearly, and this affects a large surface of the best land. The citrus orchards are moving from flood irrigated to drip

  10. The Impact of Agricultural Soil Erosion on the Global Carbon Cycle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 Pg/year to a sink of the same magnitude. By using Caesium-137 and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced...

  11. Does WEPP meet the specificity of soil erosion in steep mountain regions?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We chose the USDA-ARS-WEPP model (Water Erosion Prediction Project) to describe the soil erosion in the Urseren valley (Central Switzerland) as it seems to be one of the most promising models for steep mountain environments. Crucial model parameters were determined in the field (slope, plant species...

  12. Modeling Long-Term Soil Losses on Agricultural Fields Due to Ephemeral Gully Erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is now recognized worldwide that soil erosion on agricultural fields due to ephemeral gullies may be greater than those losses attributed to sheet and rill erosion processes. Yet it is not known whether the common practice of repairing or obliterating these gullies during annual tillage activitie...

  13. Challenges in Linking Agricultural Soil Erosion Studies to Landscape Scale Processes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion studies are usually implemented to collect data for specific processes, surface conditions or treatments. The ease of conducting the proposed erosion study, the associated quality of the data, and the confidence level of the findings, are generally related to the degree of the control o...

  14. The influence of flat residue loss by wind on soil wind erosion susceptibility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flat crop residue often contributes to wind erosion control, but it may be rearranged or removed from fields during high wind events. This paper reports the influence of flat residue loss on soil wind erosion susceptibility when standing stems co-existed. Data were collected in laboratory wind tunne...

  15. Short and long term effects of bioturbation on soil erosion and soil development in a rocky arid area

    NASA Astrophysics Data System (ADS)

    Yair, Aaron

    2014-05-01

    Short and long term effects of faunal activity on soil erosion and soil development had been largely overlooked by geomorphologists; especially in arid rocky area. A study of hillslope runoff and erosion processes in the Negev desert indicated systematic in sediment concentrations and erosion rates between rocky and colluvial surfaces. Erosion rates were always higher on the former than on the latter. Field observations drew attention to an intense burrowing and digging activity conducted by Isopods and Porcupines. The monitoring of this activity, based on a grid system,lasted ten years. Data obtained suggest a strong link between the spatial pattern of bioturbation and that of soil erosion. The study also examined the regulatory role of the spatial distribution of soil moisture on the biological activity and its long term effect on soil forming processes. TWo different environments have been recognized. The upper, rocky, hillslope areas are characterized by a positive feedback. High runoff and erosion rates remove salt from the soil, limiting salt accumulation. T the same time the colluvial slope section absorbs, at most rainstorms, all runoff generated over the upper rocky sections leading, over time, to soil salinization

  16. Using high-resolution radar images to determine vegetation cover for soil erosion assessments.

    PubMed

    Bargiel, D; Herrmann, S; Jadczyszyn, J

    2013-07-30

    Healthy soils are crucial for human well-being. Because soils are threatened worldwide, politicians recognize the need for soil protection. For example, the European Commission has launched the Thematic Strategy for Soil Protection, which requests the European member states to identify high risk areas for soil degradation. Most states use the Universal Soil Loss Equation (USLE) to assess soil erosion risk at the national scale. The USLE includes different factors, one of them is the vegetation cover and management factor (C factor). Modern satellite-based radar sensors now provide highly accurate vegetation cover data, enabling opportunities to improve the accuracy of the C factor. The presented study proves the suitability for C factor determination based on a multi-temporal classification of high-resolution radar images. Further USLE factors were derived from existing data sources (meteorological data, soil maps, digital elevation model) to conduct an USLE-based soil erosion assessment. The resulting map illustrates a qualitative assessment for soil erosion risk within a plot of about 7*12 km in an agricultural region in Poland that is very susceptible to soil erosion processes. A high erosion risk of more than 10 tonnes per ha and year was assessed to occur on 13.6% (646 ha) of the agricultural areas within the investigated plot. Further 7.8% (372 ha) of agricultural land is threaten by a medium risk of 5-10 tonnes per ha and year. Such a spatial information about areas of high or medium soil erosion risk are crucial for the development of strategies for the protection of soils. PMID:23624425

  17. Designing a national soil erosion monitoring network for England and Wales

    NASA Astrophysics Data System (ADS)

    Lark, Murray; Rawlins, Barry; Anderson, Karen; Evans, Martin; Farrow, Luke; Glendell, Miriam; James, Mike; Rickson, Jane; Quine, Timothy; Quinton, John; Brazier, Richard

    2014-05-01

    Although soil erosion is recognised as a significant threat to sustainable land use and may be a priority for action in any forthcoming EU Soil Framework Directive, those responsible for setting national policy with respect to erosion are constrained by a lack of robust, representative, data at large spatial scales. This reflects the process-orientated nature of much soil erosion research. Recognising this limitation, The UK Department for Environment, Food and Rural Affairs (Defra) established a project to pilot a cost-effective framework for monitoring of soil erosion in England and Wales (E&W). The pilot will compare different soil erosion monitoring methods at a site scale and provide statistical information for the final design of the full national monitoring network that will: provide unbiased estimates of the spatial mean of soil erosion rate across E&W (tonnes ha-1 yr-1) for each of three land-use classes - arable and horticultural grassland upland and semi-natural habitats quantify the uncertainty of these estimates with confidence intervals. Probability (design-based) sampling provides most efficient unbiased estimates of spatial means. In this study, a 16 hectare area (a square of 400 x 400 m) positioned at the centre of a 1-km grid cell, selected at random from mapped land use across E&W, provided the sampling support for measurement of erosion rates, with at least 94% of the support area corresponding to the target land use classes. Very small or zero erosion rates likely to be encountered at many sites reduce the sampling efficiency and make it difficult to compare different methods of soil erosion monitoring. Therefore, to increase the proportion of samples with larger erosion rates without biasing our estimates, we increased the inclusion probability density in areas where the erosion rate is likely to be large by using stratified random sampling. First, each sampling domain (land use class in E&W) was divided into strata; e.g. two sub

  18. Distributed soil loss estimation system including ephemeral gully development and tillage erosion

    NASA Astrophysics Data System (ADS)

    Vieira, D. A. N.; Dabney, S. M.; Yoder, D. C.

    2015-03-01

    A new modelling system is being developed to provide spatially-distributed runoff and soil erosion predictions for conservation planning that integrates the 2D grid-based variant of the Revised Universal Soil Loss Equation, version 2 model (RUSLER), the Ephemeral Gully Erosion Estimator (EphGEE), and the Tillage Erosion and Landscape Evolution Model (TELEM). Digital representations of the area of interest (field, farm or entire watershed) are created using high-resolution topography and data retrieved from established databases of soil properties, climate, and agricultural operations. The system utilizes a library of processing tools (LibRaster) to deduce surface drainage from topography, determine the location of potential ephemeral gullies, and subdivide the study area into catchments for calculations of runoff and sheet-and-rill erosion using RUSLER. EphGEE computes gully evolution based on local soil erodibility and flow and sediment transport conditions. Annual tillage-induced morphological changes are computed separately by TELEM.

  19. NEW GIS WATERSHED ANALYSIS TOOLS FOR SOIL CHARACTERIZATION AND EROSION AND SEDIMENTATION MODELING

    EPA Science Inventory

    A comprehensive procedure for computing soil erosion and sediment delivery metrics has been developed which utilizes a suite of automated scripts and a pair of processing-intensive executable programs operating on a personal computer platform.

  20. Reassessment of soil erosion on the Chinese loess plateau: were rates overestimated?

    NASA Astrophysics Data System (ADS)

    Zhao, Jianlin; Govers, Gerard

    2014-05-01

    Several studies have estimated regional soil erosion rates (rill and interrill erosion) on the Chinese loess plateau using an erosion model such as the RUSLE (e.g. Fu et al., 2011; Sun et al., 2013). However, the question may be asked whether such estimates are realistic: studies have shown that the use of models for large areas may lead to significant overestimations (Quinton et al., 2010). In this study, soil erosion rates on the Chinese loess plateau were reevaluated by using field measured soil erosion data from erosion plots (216 plots and 1380 plot years) in combination with a careful extrapolation procedure. Data analysis showed that the relationship between slope and erosion rate on arable land could be well described by erosion-slope relationships reported in the literature (Nearing, 1997). The increase of average erosion rate with slope length was clearly degressive, as could be expected from earlier research. However, for plots with permanent vegetation (grassland, shrub, forest) no relationship was found between erosion rates and slope gradient and/or slope length. This is important, as it implies that spatial variations of erosion on permanently vegetated areas cannot be modeled using topographical functions derived from observations on arable land. Application of relationships developed for arable land will lead to a significant overestimation of soil erosion rates. Based on our analysis we estimate the total soil erosion rate in the Chinese Loess plateau averages ca. 6.78 t ha-1 yr-1 for the whole loess plateau, resulting in a total sediment mobilisation of ca. 0.38 Gt yr-1. Erosion rates on arable land average ca. 15.10 t ha-1 yr-1. These estimates are 2 to 3 times lower than previously published estimates. The main reason why previous estimates are likely to be too high is that the values of (R)USLE parameters such as K, P and LS factor were overestimated. Overestimations of the K factor are due to the reliance of nomograph calculations, resulting

  1. Soil erosion under climate change: simulatingthe response of temperature and rainfall changes in three UK catchments

    NASA Astrophysics Data System (ADS)

    Ciampalini, Rossano; Walker-Springett, Kate J.; Constantine, José Antonio; Hales, Tristram C.

    2015-04-01

    Soil erosion by water cost in environmental damages across the Great Britain is estimated in over £200m (2014 GBP) each year and could increase for the effect of climate change. Assessing the potential for increased climate-driven soil erosion, due to the several water processes involved (e.g., infiltration excess, return flow, direct precipitation onto saturated soil),is recognizedas a complex task. Climate change can have a positive and direct effect on soil erosionsuch the case of increasing rainfall in amount and intensity, or an indirect effect through the variation of the atmospheric CO2 level, which can improve plant productivityandwater infiltration capacity of soil reducing the likelihood of soil erosion. Changes in vegetation patterns and typologies with a different protection effect can lead also the soil system to dramatic changes in soil erosion rates, potentially amplifying or ameliorating the direct effects of climate change.Climate, vegetation and soil erosion are thus connected and several feedback effects could be accounted in the study of global change. Understanding these interactions may be a primary goal for clarifying the impact of global change on soil erosion and its consequences on related soil functions such as water and organic carbon storage support to vegetation and agricultural production. In this research, focused on three UK catchments (i.e. Conwy, 627 km2, Wales; Ehen, 225 km2, England; and Dee, 2100 km2, Scotland), we simulated soil erosionapplying SRES climatic scenarios(IPCC, 2000) for different CO2 emission levels. We modelled using Pesera "The Pan European Soil Erosion Risk Assessment" (Kirkby et al., 2004), a model for vegetation growing and soil erosion evaluation at regional scale. For each catchment,we realised a sensitivity - analysis - like test investigating different increments in temperature and rainfall, then, we compared the results of the SRES scenarios with the issues of the parametric sensitivity analysis. The

  2. Decomposition and humification of soil organic carbon after land use change on erosion prone slopes

    NASA Astrophysics Data System (ADS)

    Häring, Volker; Fischer, Holger; Cadisch, Georg; Stahr, Karl

    2014-05-01

    Soil organic carbon decline after land use change from forest to maize usually lead to soil degradation and elevated CO2 emissions. However, limited knowledge is available on the interactions between rates of SOC change and soil erosion and how SOC dynamics vary with soil depth and clay contents. The 13C isotope based CIDE approach (Carbon Input, Decomposition and Erosion) was developed to determine SOC dynamics on erosion prone slopes. The aims of the present study were: (1) to test the applicability of the CIDE approach to determine rates of decomposition and SOC input under particular considerations of concurrent erosion events on three soil types (Alisol, Luvisol, Vertisol), (2) to adapt the CIDE approach to deeper soil layers (10-20 and 20-30 cm) and (3) to determine the variation of decomposition and SOC input with soil depth and soil texture. SOC dynamics were determined for bulk soil and physically separated SOC fractions along three chronosequences after land use change from forest to maize (up to 21 years) in northwestern Vietnam. Consideration of the effects of soil erosion on SOC dynamics by the CIDE approach yielded a higher total SOC loss (6 to 32%), a lower decomposition (13 to 40%) and a lower SOC input (14 to 31%) relative to the values derived from a commonly applied 13C isotope based mass balance approach. Comparison of decomposition between depth layers revealed that tillage accelerated decomposition in the plough layer (0-10 cm), accounting for 3 to 34% of total decomposition. With increasing clay contents SOC input increased. In addition, decomposition increased with increasing clay contents, too, being attributed to decomposition of exposed labile SOC which was attached to clay particles in the sand sized stable aggregate fraction. This study suggests that in situ SOC dynamics on erosion prone slopes are commonly misrepresented by erosion unadjusted approaches.

  3. Soil erosion by snow gliding - a first quantification attempt in a sub-alpine area, Switzerland

    NASA Astrophysics Data System (ADS)

    Meusburger, K.; Leitinger, G.; Mabit, L.; Mueller, M. H.; Walter, A.; Alewell, C.

    2014-03-01

    Snow processes might be one important driver of soil erosion in Alpine grasslands and thus the unknown variable when erosion modelling is attempted. The aim of this study is to assess the importance of snow gliding as soil erosion agent for four different land use/land cover types in a sub-alpine area in Switzerland. We used three different approaches to estimate soil erosion rates: sediment yield measurements in snow glide deposits, the fallout radionuclide 137Cs, and modelling with the Revised Universal Soil Loss Equation (RUSLE). The RUSLE model is suitable to estimate soil loss by water erosion, while the 137Cs method integrates soil loss due to all erosion agents involved. Thus, we hypothesise that the soil erosion rates determined with the 137Cs method are higher and that the observed discrepancy between the soil erosion rate of RUSLE and the 137Cs method is related to snow gliding and sediment concentrations in the snow glide deposits. Cumulative snow glide distance was measured for the sites in the winter 2009/10 and modelled for the surrounding area with the Spatial Snow Glide Model (SSGM). Measured snow glide distance ranged from 2 to 189 cm, with lower values at the north facing slopes. We observed a reduction of snow glide distance with increasing surface roughness of the vegetation, which is important information with respect to conservation planning and expected land use changes in the Alps. Our hypothesis was confirmed: the difference of RUSLE and 137Cs erosion rates was related to the measured snow glide distance (R2= 0.64; p < 0.005) and snow sediment yields (R2 = 0.39; p = 0.13). A high difference (lower proportion of water erosion compared to total net erosion) was observed for high snow glide rates and vice versa. The SSGM reproduced the relative difference of the measured snow glide values under different land uses and land cover types. The resulting map highlighted the relevance of snow gliding for large parts of the investigated area. Based

  4. Developing relations between soil erodibilty factors in two different soil erosion prediction models (USLE/RUSLE and wWEPP) and fludization bed technique for mechanical soil cohesion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion models are valuable analysis tools that scientists and engineers use to examine observed data sets and predict the effects of possible future soil loss. In the area of water erosion, a variety of modeling technologies are available, ranging from solely qualitative models, to merely quan...

  5. RUSLE2015: Modelling soil erosion at continental scale using high resolution input layers

    NASA Astrophysics Data System (ADS)

    Panagos, Panos; Borrelli, Pasquale; Meusburger, Katrin; Poesen, Jean; Ballabio, Cristiano; Lugato, Emanuele; Montanarella, Luca; Alewell, Christine

    2016-04-01

    Soil erosion by water is one of the most widespread forms of soil degradation in the Europe. On the occasion of the 2015 celebration of the International Year of Soils, the European Commission's Joint Research Centre (JRC) published the RUSLE2015, a modified modelling approach for assessing soil erosion in Europe by using the best available input data layers. The objective of the recent assessment performed with RUSLE2015 was to improve our knowledge and understanding of soil erosion by water across the European Union and to accentuate the differences and similarities between different regions and countries beyond national borders and nationally adapted models. RUSLE2015 has maximized the use of available homogeneous, updated, pan-European datasets (LUCAS topsoil, LUCAS survey, GAEC, Eurostat crops, Eurostat Management Practices, REDES, DEM 25m, CORINE, European Soil Database) and have used the best suited approach at European scale for modelling soil erosion. The collaboration of JRC with many scientists around Europe and numerous prominent European universities and institutes resulted in an improved assessment of individual risk factors (rainfall erosivity, soil erodibility, cover-management, topography and support practices) and a final harmonized European soil erosion map at high resolution. The mean soil loss rate in the European Union's erosion-prone lands (agricultural, forests and semi-natural areas) was found to be 2.46 t ha‑1 yr‑1, resulting in a total soil loss of 970 Mt annually; equal to an area the size of Berlin (assuming a removal of 1 meter). According to the RUSLE2015 model approximately 12.7% of arable lands in the European Union is estimated to suffer from moderate to high erosion(>5 t ha‑1 yr‑1). This equates to an area of 140,373 km2 which equals to the surface area of Greece (Environmental Science & Policy, 54, 438-447; 2015). Even the mean erosion rate outstrips the mean formation rate (<1.4 tonnes per ha annually). The recent RUSLE

  6. Modelling the impact of soil erosion on element transfer processes in agro-ecosystems

    NASA Astrophysics Data System (ADS)

    Shi, Pu; Della Peruta, Raniero; Keller, Armin; Schulin, Rainer

    2014-05-01

    Soil erosion is the main cause for loss of soil fertility worldwide. It can lead to degradation of soil structure, pollution of water bodies, decrease in crop productivity, and excessive accumulation of nutrients and trace elements in locations where eroded sediments are re-deposited. Research into the element transfer in fields and landscapes associated with erosion has hitherto focused on the assessment of element mobilization and nutrient export into aquatic ecosystems. Less is known about the role of erosion in element redistribution within terrestrial environments. Hence, we are developing a GIS-linked model that describes and visualizes areal patterns of particle-bound element transfer processes at the field to catchment scale, adapting and combining existing process-based mechanistic models of soil erosion, soil hydrology, sediment transport, crop growth, soil nutrient turnover and soil pollutant dynamics. The model will be tested in a case study of selected catchment in the framework of the Swiss National Research Program 'Sustainable Use of Soil as a Resource' (NRP 68). The goal is to create a tool that can be used to aid monitoring nutrient and pollutant fluxes associated with erosion in agricultural landscapes, in particular to identify hot spots of excessive pollutant accumulation related to the deposition of eroded sediments on agricultural land for different scenarios of land use and climate change, and to support the evaluation of land management strategies aiming to control them.

  7. Impact of erosion and tillage on the productivity and quality of selected semiarid soils of Iran

    NASA Astrophysics Data System (ADS)

    Mehdizade, B.; Asadi, H.; Shabanpour, M.; Ghadiri, H.

    2013-09-01

    This greenhouse research was carried out to study the effects of water and tillage erosion on agricultural productivity and soil quality in soil samples from a semiarid region of Iran. A factorial experiment of complete randomized block design was used to compare the effects of soil erosion (eroded and non-eroded soils), slope position, water stress and fertilizer (N-P-K) on yield and yield components of wheat as soil productivity index. The results showed that erosion ie water and tillage erosion has a significant effect (p<0.01) in decreasing soil productivity due to its negative impact on soil organic matter, nutrients (N and K) and hydraulic conductivity. Complete N-P-K fertilization and water stress had significant effects on increasing and decreasing of wheat yield, respectively. The effect of water stress in particular was so high that it could eclipse the erosion impact on yield reduction. Wheat dry matter and grain mass on foot and mid slopes were significantly higher than that on upslope positions where total N and available K were the lowest and equivalent calcium carbonate the highest. Saturated hydraulic conductivity and total nitrogen were found to be the most important soil properties as far as their correlations to wheat yield are concerned.

  8. Effects of Revegetation on Soil Organic Carbon Storage and Erosion-Induced Carbon Loss under Extreme Rainstorms in the Hill and Gully Region of the Loess Plateau

    PubMed Central

    Li, Yujin; Jiao, Juying; Wang, Zhijie; Cao, Binting; Wei, Yanhong; Hu, Shu

    2016-01-01

    Background: The Loess Plateau, an ecologically vulnerable region, has long been suffering from serious soil erosion. Revegetation has been implemented to control soil erosion and improve ecosystems in the Loess Plateau region through a series of ecological recovery programs. However, the increasing atmospheric CO2 as a result of human intervention is affecting the climate by global warming, resulting in the greater frequency and intensity of extreme weather events, such as storms that may weaken the effectiveness of revegetation and cause severe soil erosion. Most research to date has evaluated the effectiveness of revegetation on soil properties and soil erosion of different land use or vegetation types. Here, we study the effect of revegetation on soil organic carbon (SOC) storage and erosion-induced carbon loss related to different plant communities, particularly under extreme rainstorm events. Materials and methods: The erosion-pin method was used to quantify soil erosion, and soil samples were taken at soil depths of 0–5 cm, 5–10 cm and 10–20 cm to determine the SOC content for 13 typical hillside revegetation communities in the year of 2013, which had the highest rainfall with broad range, long duration and high intensity since 1945, in the Yanhe watershed. Results and discussion: The SOC concentrations of all plant communities increased with soil depth when compared with slope cropland, and significant increases (p < 0.05) were observed for most shrub and forest communities, particularly for natural ones. Taking the natural secondary forest community as reference (i.e., soil loss and SOC loss were both 1.0), the relative soil loss and SOC loss of the other 12 plant communities in 2013 ranged from 1.5 to 9.4 and 0.30 to 1.73, respectively. Natural shrub and forest communities showed greater resistance to rainstorm erosion than grassland communities. The natural grassland communities with lower SOC content produced lower SOC loss even with higher soil

  9. Short and Long Term Effects of Bioturbation on Soil Erosion and Soil Developmemt in an Arid Rocky Area

    NASA Astrophysics Data System (ADS)

    Yair, A.

    2014-12-01

    Short and long term effects of faunal activity on soil ersion and soil development had been largely overlooked by geomorphologists; especially in rocky arid areas. A study of hiillslope runoff and erosion processes, coducted in the Negev desert, indicated systematic differences in sediment concentration and erosion rates between rocky and colluvial surfaces.. Field observations drew attention to intense burrowing and digging activity of Porcupines and Isopods. Erosion rates were always higher over the rocky than over the colluvial areas. The monitoring of this activity, based on a grid system which consists of rows 5m wide, lasted ten years. Data obtained suggest a link between the spatial pattern of bioturbation and that of soil erosion. The study also examines, through feebback processes , the vregulatory role of bioturbation on soil erosion and soil forming processes. Due to bioturbation two distinct envirobments were recognized.The rocky, upper hilllsope areas, are characterized by a positive feedback process. High runoff and erosion rates remove salt from the soil, preventing thus salt accumulation. At the same time the colluviual slope sections absorb, at most storms, all runoff over the upper rocky slope sectioins leading, over time, tooil salinization

  10. Effects of erosion in the fate of soil organic carbon and soil aggregation in a burned Mediterranean hill-slope

    NASA Astrophysics Data System (ADS)

    Campo, Julian; Cammeraat, Erik; Gimeno-García, Eugenia; Andreu, Vicente

    2016-04-01

    The Intergovernmental Panel on Climate Change indicated a higher degree of confidence that meteorological conditions associated to climate change will be propitious to increasing extreme events manifested, among others, in bigger and more frequent wildfires (IPCC, 2014). Wildfires contribute to shaping the landscape, and also the geomorphological and hydrological processes that operate on soil are affected (Bento-Gonçalves et al., 2012). Whereas, it is well documented that wildfires produce significant changes on erosion processes, the associated fate of soil organic carbon (SOC) has received less attention. This research assesses this gap by studying the loss, redistribution, and stabilization of SOC in a Mediterranean forest hill-slope burned the 28-08-2014, with high severity fire, at the Natural Park of Sierra de Espadán, Spain (39°50'45.11"N, 0°22'20.52"W). To this end, soil was sampled (19-9-2014) in the foot's slope (depositional), middle part (transport) and top (eroding) at two depths (<2 cm, 2-5 cm), and in two environments (under canopy soil: UC; bare soil: BS). Sediments were collected from four sediment fences constructed at the foot's slope, and together with soil samples, analysed with regard to SOC content and aggregate stability (AS). The main objective is to increase the understanding on the fate of SOC in Mediterranean burned areas experiencing soil erosion, transport and deposition, with special attention to the role of aggregation and disaggregation in redistribution processes. Immediately after the fire, SOC content was high (≈50 gC kg-1) as well as the AS (water drop test>146 drops). Significant differences (ANOVA, p<0.05) in SOC contents were observed between environments (UC>BS) and soil depths (topsoil>subsoil). However, no significant differences were observed among eroding (58.8+20.8 gC kg-1), transport (67.3+34.4 gC kg-1), and depositional zones (62.0+31.3 gC kg-1), which is not in agreement with other SOC redistribution studies

  11. Estimating soil resistance to erosion on plot scale - Do we really need artificial rainfall simulations?

    NASA Astrophysics Data System (ADS)

    Schindewolf, Marcus; Kaiser, Andreas; Schultze, Nico; Kunth, Franziska; Käpermann, Philipp; Schmidt, Jürgen

    2014-05-01

    Rainfall simulators are an important tool for research of initial detachment and infiltration. Recent publications highlighted the great importance of simulator calibration in soil erosion studies. However, falling velocity and size distribution of raindrops assumably play a significant role only on the first meters of the slope. With increasing slope length runoff volume increases while effects of falling droplets become negligible. In this regard the plot length of rainfall simulators is determining the processes we measure. For reasons of efficiency and repeatability such experiments are mostly conducted on small plots, which imply strict limitations in process simulation. In order to simulate the more important runoff driven erosion processes small plots need an additional sediment loaded runoff surplus, which allows virtually enlarged slope lengths. The presented study shows examples of runoff feeding devices for parameter identification of the process based soil erosion and deposition model EROSION 3D for certain rainfall simulators and varying slope lengths (0.65-3 m). Resulting soil erosion resistance values are reasonable and comparable to previous investigations using a large scale rainfall simulator. Additionally the devices were tested without rainfall yielding to similar erosion resistance values. That leads to the following conclusion: If we want to simulate important erosion processes with artificial rainfall simulations, additional runoff is needed for virtual plot length enlargement. The effort we made referring to calibration of rainfall simulators we also should make in extending the devices by runoff reflux approaches in order to model slope size erosion processes.

  12. Use of dendrochronological method in Pinus halepensis to estimate the soil erosion in the South East of Madrid (Spain).

    PubMed

    Pérez-Rodríguez, Raquel; Marques, Maria Jose; Bienes, Ramón

    2007-05-25

    The rate of soil erosion in pine forests (Pinus halepensis) located in the Southeast of Madrid has been estimated using dendrochronological analysis based on the change in ring-growth pattern from concentric to eccentric when the root is exposed. Using 49 roots spread across five inclined areas, it has been found that the length and direction of the hillsides, as well as their vegetation cover affect the rate of erosion, while the slope itself does not. The erosion rates found for the different areas studied vary between 3.5 and 8.8 mm year(-1), that is between 40 and 101 t ha(-1) year(-1) respectively. These values are between 2 and 3 times greater than those predicted by USLE, for which this equation underestimates soil loss for Central Spain's Mediterranean conditions. Nonetheless, both methods (using dendrochronology to determine actual soil loss and theoretical prediction with USLE) are able to establish the same significant differences among the areas studied, allowing for the comparative estimate of the severity of the area's erosion problem. PMID:17379273

  13. Modeling of soil erosion and sediment transport in the East River Basin in southern China.

    PubMed

    Wu, Yiping; Chen, Ji

    2012-12-15

    Soil erosion is a major global environmental problem that has caused many issues involving land degradation, sedimentation of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and sediment transport along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical sediment transport method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating sediment transport process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low sediment concentrations along the river. We also found that the East River is mainly characterized by sediment deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in sediment modeling for other basins worldwide. PMID:23137981

  14. Modeling of soil erosion and sediment transport in the East River Basin in southern China

    USGS Publications Warehouse

    Wu, Yping; Chen, Ji

    2012-01-01

    Soil erosion is a major global environmental problem that has caused many issues involving land degradation, sedimentation of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and sediment transport along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical sediment transport method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating sediment transport process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low sediment concentrations along the river. We also found that the East River is mainly characterized by sediment deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in sediment modeling for other basins worldwide.

  15. Soil hydraulic properties affected by topsoil thickness in cultivated switchgrass and corn-soybean rotation production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Loss of productive topsoil by soil erosion over time can reduce the productive capacity of soil and can significantly affect soil hydraulic properties. This study evaluated the effects of reduced topsoil thickness and perennial switchgrass (Panicum virgatum L.) versus corn (Zea mays L.)/soybean [Gly...

  16. Quantifying intrinsic and extrinsic factors affecting soil erodibility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erodibility has traditionally been conceived as a soil dependent parameter that can be quantified from intrinsic soil properties that usually stay constant. Development of erosion prediction equations, from the empirical-based Universal Soil Loss Equation (USLE) to a more processed-based Water ...

  17. Long-term relationships among pesticide applications, mobility, and soil erosion in a vineyard watershed

    PubMed Central

    Sabatier, Pierre; Poulenard, Jérôme; Fanget, Bernard; Reyss, Jean-Louis; Develle, Anne-Lise; Wilhelm, Bruno; Ployon, Estelle; Pignol, Cécile; Naffrechoux, Emmanuel; Dorioz, Jean-Marcel; Montuelle, Bernard; Arnaud, Fabien

    2014-01-01

    Agricultural pesticide use has increased worldwide during the last several decades, but the long-term fate, storage, and transfer dynamics of pesticides in a changing environment are poorly understood. Many pesticides have been progressively banned, but in numerous cases, these molecules are stable and may persist in soils, sediments, and ice. Many studies have addressed the question of their possible remobilization as a result of global change. In this article, we present a retro-observation approach based on lake sediment records to monitor micropollutants and to evaluate the long-term succession and diffuse transfer of herbicides, fungicides, and insecticide treatments in a vineyard catchment in France. The sediment allows for a reliable reconstruction of past pesticide use through time, validated by the historical introduction, use, and banning of these organic and inorganic pesticides in local vineyards. Our results also revealed how changes in these practices affect storage conditions and, consequently, the pesticides' transfer dynamics. For example, the use of postemergence herbicides (glyphosate), which induce an increase in soil erosion, led to a release of a banned remnant pesticide (dichlorodiphenyltrichloroethane, DDT), which had been previously stored in vineyard soil, back into the environment. Management strategies of ecotoxicological risk would be well served by recognition of the diversity of compounds stored in various environmental sinks, such as agriculture soil, and their capability to become sources when environmental conditions change. PMID:25313074

  18. Long-term relationships among pesticide applications, mobility, and soil erosion in a vineyard watershed.

    PubMed

    Sabatier, Pierre; Poulenard, Jérôme; Fanget, Bernard; Reyss, Jean-Louis; Develle, Anne-Lise; Wilhelm, Bruno; Ployon, Estelle; Pignol, Cécile; Naffrechoux, Emmanuel; Dorioz, Jean-Marcel; Montuelle, Bernard; Arnaud, Fabien

    2014-11-01

    Agricultural pesticide use has increased worldwide during the last several decades, but the long-term fate, storage, and transfer dynamics of pesticides in a changing environment are poorly understood. Many pesticides have been progressively banned, but in numerous cases, these molecules are stable and may persist in soils, sediments, and ice. Many studies have addressed the question of their possible remobilization as a result of global change. In this article, we present a retro-observation approach based on lake sediment records to monitor micropollutants and to evaluate the long-term succession and diffuse transfer of herbicides, fungicides, and insecticide treatments in a vineyard catchment in France. The sediment allows for a reliable reconstruction of past pesticide use through time, validated by the historical introduction, use, and banning of these organic and inorganic pesticides in local vineyards. Our results also revealed how changes in these practices affect storage conditions and, consequently, the pesticides' transfer dynamics. For example, the use of postemergence herbicides (glyphosate), which induce an increase in soil erosion, led to a release of a banned remnant pesticide (dichlorodiphenyltrichloroethane, DDT), which had been previously stored in vineyard soil, back into the environment. Management strategies of ecotoxicological risk would be well served by recognition of the diversity of compounds stored in various environmental sinks, such as agriculture soil, and their capability to become sources when environmental conditions change. PMID:25313074

  19. Long-term relationships among pesticide applications, mobility, and soil erosion in a vineyard watershed

    NASA Astrophysics Data System (ADS)

    Sabatier, Pierre; Poulenard, Jérôme; Fanget, Bernard; Reyss, Jean-Louis; Develle, Anne-Lise; Wilhelm, Bruno; Ployon, Estelle; Pignol, Cécile; Naffrechoux, Emmanuel; Dorioz, Jean-Marcel; Montuelle, Bernard; Arnaud, Fabien

    2014-11-01

    Agricultural pesticide use has increased worldwide during the last several decades, but the long-term fate, storage, and transfer dynamics of pesticides in a changing environment are poorly understood. Many pesticides have been progressively banned, but in numerous cases, these molecules are stable and may persist in soils, sediments, and ice. Many studies have addressed the question of their possible remobilization as a result of global change. In this article, we present a retro-observation approach based on lake sediment records to monitor micropollutants and to evaluate the long-term succession and diffuse transfer of herbicides, fungicides, and insecticide treatments in a vineyard catchment in France. The sediment allows for a reliable reconstruction of past pesticide use through time, validated by the historical introduction, use, and banning of these organic and inorganic pesticides in local vineyards. Our results also revealed how changes in these practices affect storage conditions and, consequently, the pesticides' transfer dynamics. For example, the use of postemergence herbicides (glyphosate), which induce an increase in soil erosion, led to a release of a banned remnant pesticide (dichlorodiphenyltrichloroethane, DDT), which had been previously stored in vineyard soil, back into the environment. Management strategies of ecotoxicological risk would be well served by recognition of the diversity of compounds stored in various environmental sinks, such as agriculture soil, and their capability to become sources when environmental conditions change.

  20. Soil erosion studies in western Europe from the early 1980s

    NASA Astrophysics Data System (ADS)

    Boardman, John; Favis-Mortlock, David

    2013-04-01

    Before the early 1980s, scientific interest in soil erosion in western Europe was minimal. On British soils, for example, high rates of erosion were considered unlikely: "[Soil erosion in Britain] cannot in any way be regarded as a national menace, as can erosion in some other countries" (Jacks, 1954). There was some truth in this perception. By comparison with (for example) the USA, European rainfall was seen as relatively modest in terms of amount and intensity; and European land usage was still generally based on traditional practices which rather rarely left land vulnerable to erosion. However, studies from the late 1970s and early 1980s revealed a growing erosion problem. The earliest UK studies were opportunistic descriptions of large and unusual erosion events which lacked statistical rigour. They led, however, to a growing scientific appreciation of the potential for soil erosion even in those areas which were not previously thought to be erosion-prone e.g. Evans and Northcliff (1978), Boardman (1983). These studies were followed by more ambitious attempts to assess erosion over larger spatial and longer temporal scales: Evans, 1982-86 in England and Wales; Boardman , 1982-91 on the South Downs. Along with this move from considering only single events was a growing appreciation that the most damaging impact of European erosion, in contrast with erosion in the US mid-west and in the tropics, was not on-site but off-site. During these more ambitious monitoring exercises data was also collected on off-site damage by muddy runoff. This led to the realisation that such off-site impacts could be the product of frequent, low magnitude events. This insight has led directly to current concerns regarding agricultural impacts on freshwater systems as exemplified in the Water Framework Directive. These changes in emphasis necessitated a change in experimental and observational approach from small plot to the field scale. The early 1980s also saw the development of

  1. Modeling and analysis of Soil Erosion processes by the River Basins model: The Case Study of the Krivacki Potok Watershed, Montenegro

    NASA Astrophysics Data System (ADS)

    Vujacic, Dusko; Barovic, Goran; Mijanovic, Dragica; Spalevic, Velibor; Curovic, Milic; Tanaskovic, Vjekoslav; Djurovic, Nevenka

    2016-04-01

    The objective of this research was to study soil erosion processes in one of Northern Montenegrin watersheds, the Krivacki Potok Watershed of the Polimlje River Basin, using modeling techniques: the River Basins computer-graphic model, based on the analytical Erosion Potential Method (EPM) of Gavrilovic for calculation of runoff and soil loss. Our findings indicate a low potential of soil erosion risk, with 554 m³ yr‑1 of annual sediment yield; an area-specific sediment yield of 180 m³km-2 yr‑1. The calculation outcomes were validated for the entire 57 River Basins of Polimlje, through measurements of lake sediment deposition at the Potpec hydropower plant dam. According to our analysis, the Krivacki Potok drainage basin is with the relatively low sediment discharge; according to the erosion type, it is mixed erosion. The value of the Z coefficient was calculated on 0.297, what indicates that the river basin belongs to 4th destruction category (of five). The calculated peak discharge from the river basin was 73 m3s-1 for the incidence of 100 years and there is a possibility for large flood waves to appear in the studied river basin. Using the adequate computer-graphic and analytical modeling tools, we improved the knowledge on the soil erosion processes of the river basins of this part of Montenegro. The computer-graphic River Basins model of Spalevic, which is based on the EPM analytical method of Gavrilovic, is highly recommended for soil erosion modelling in other river basins of the Southeastern Europe. This is because of its reliable detection and appropriate classification of the areas affected by the soil loss caused by soil erosion, at the same time taking into consideration interactions between the various environmental elements such as Physical-Geographical Features, Climate, Geological, Pedological characteristics, including the analysis of Land Use, all calculated at the catchment scale.

  2. Development of a coupled soil erosion and large-scale hydrology modeling system

    NASA Astrophysics Data System (ADS)

    Mao, Dazhi; Cherkauer, Keith A.; Flanagan, Dennis C.

    2010-08-01

    Soil erosion models are usually limited in their application to the field scale; however, the management of land resources requires information at the regional scale. Large-scale physically based land surface schemes (LSS) provide estimates of regional scale hydrologic processes that contribute to erosion. If scaling issues are adequately addressed, coupling an LSS to a physically based erosion model can provide a tool to study the regional impact of soil erosion. A coupling scheme was developed using the Variable Infiltration Capacity (VIC) model to produce hydrologic inputs for the stand-alone Water Erosion Prediction Project-Hillslope Erosion (WEPP-HE) program, accounting for both temporal and spatial scaling issues. Precipitation events were disaggregated from daily to hourly and used with the VIC model to generate hydrologic fluxes. Slope profiles were downscaled from 30 arc second to 30 m hillslopes. Additionally, soil texture and erodibility were adjusted with simplified assumptions based on the full WEPP model. Soil erosion at the large scale was represented on a VIC model grid cell basis by applying WEPP-HE to subsamples of 30 m hillslopes. On an average annual basis, results showed that the coupled model was comparable with full WEPP model predictions. On an event basis, the coupled model system captured more small erosion events, with erodibility adjustments of the same magnitude as from the full WEPP model simulations. Differences in results can be attributed to discrepancies in hydrologic data calculations and simplified assumptions in vegetation and soil erodibility. Overall, the coupled model demonstrated the feasibility of erosion prediction for large river basins.

  3. Influence of soil tillage and erosion on the dispersion of glyphosate and aminomethylphosphonic acid in agricultural soils

    NASA Astrophysics Data System (ADS)

    Todorovic, Gorana Rampazzo; Rampazzo, Nicola; Mentler, Axel; Blum, Winfried E. H.; Eder, Alexander; Strauss, Peter

    2014-03-01

    Erosion processes can strongly influence the dissipation of glyphosate and aminomethylphosphonic acid applied with Roundup Max® in agricultural soils; in addition, the soil structure state shortly before erosive precipitations fall can be a key parameter for the distribution of glyphosate and its metabolite. Field rain simulation experiments showed that severe erosion processes immediately after application of Roundup Max® can lead to serious unexpected glyphosate loss even in soils with a high presumed adsorption like the Cambisols, if their structure is unfavourable. In one of the no-tillage-plot of the Cambisol, up to 47% of the applied glyphosate amount was dissipated with surface run-off. Moreover, at the Chernozem site with high erosion risk and lower adsorption potential, glyphosate could be found in collected percolation water transported far outside the 2x2 m experimental plots. Traces of glyphosate were found also outside the treated agricultural fields.

  4. Plutonium as a tracer for soil erosion assessment in northeast China.

    PubMed

    Xu, Yihong; Qiao, Jixin; Pan, Shaoming; Hou, Xiaolin; Roos, Per; Cao, Liguo

    2015-04-01

    Soil erosion is one of the most serious environmental and agricultural problems faced by human society. Assessing intensity is an important issue for controlling soil erosion and improving eco-environmental quality. The suitability of the application of plutonium (Pu) as a tracer for soil erosion assessment in northeast China was investigated by comparing with that of 137Cs. Here we build on preliminary work, in which we investigated the potential of Pu as a soil erosion tracer by sampling additional reference sites and potential erosive sites, along the Liaodong Bay region in northeast China, for Pu isotopes and 137Cs. 240Pu/239Pu atomic ratios in all samples were approximately 0.18, which indicated that the dominant source of Pu was the global fallout. Pu showed very similar distribution patterns to those of 137Cs at both uncultivated and cultivated sites. 239+240Pu concentrations in all uncultivated soil cores followed an exponential decline with soil depth, whereas at cultivated sites, Pu was homogenously distributed in plow horizons. Factors such as planted crop types, as well as methods and frequencies of irrigation and tillage were suggested to influence the distribution of radionuclides in cultivated land. The baseline inventories of 239+240Pu and 137Cs were 88.4 and 1688 Bq m(-2) respectively. Soil erosion rates estimated by 239+240Pu tracing method were consistent with those obtained by the 137Cs method, confirming that Pu is an effective tracer with a similar tracing behavior to that of 137Cs for soil erosion assessment. PMID:25544336

  5. Soil erosion and effluent particle size distribution under different initial conditions and rock fragment coverage

    NASA Astrophysics Data System (ADS)

    Jomaa, S.; Barry, D. A.; Brovelli, A.; Heng, B. C. P.; Sander, G. C.; Parlange, J.-Y.

    2012-04-01

    It is well known that the presence of rock fragments on the soil surface and the soil's initial characteristics (moisture content, surface roughness, bulk density, etc.) are key factors influencing soil erosion dynamics and sediment delivery. In addition, the interaction of these factors increases the complexity of soil erosion patterns and makes predictions more difficult. The aim of this study was (i) to investigate the effect of soil initial conditions and rock fragment coverage on soil erosion yields and effluent particle size distribution and (ii) to evaluate to what extent the rock fragment coverage controls this relationship. Three laboratory flume experiments with constant precipitation rate of 74 mm/h on a loamy soil parcel with a 2% slope were performed. Experiments with duration of 2 h were conducted using the 6-m × 2-m EPFL erosion flume. During each experiment two conditions were considered, a bare soil and a rock fragment-protected (with 40% coverage) soil. The initial soil surface state was varied between the three experiments, from a freshly re-ploughed and almost dry condition to a compacted soil with a well-developed shield layer and high moisture content. Experiments were designed so that rain splash was the primary driver of soil erosion. Results showed that the amount of eroded mass was highly controlled by the initial soil conditions and whether the steady-state equilibrium was un-, partially- or fully- developed during the previous event. Additionally, results revealed that sediment yields and particle size composition in the initial part of an erosion event are more sensitive to the erosion history than the long-time behaviour. This latter appears to be mainly controlled by rainfall intensity. If steady-state was achieved for a previous event, then the next event consistently produced concentrations for each size class that peaked rapidly, and then declined gradually to steady-state equilibrium. If steady state was not obtained, then

  6. Integrating Novel Field, Laboratory and Modelling Techniques to Upscale Estimates of Soil Erosion

    NASA Astrophysics Data System (ADS)

    Wainwright, John; Parsons, Anthony; Cooper, James; Long, Edward; Hargrave, Graham; Kitchener, Ben; Hewett, Caspar; Onda, Yuichi; Furukawa, Tomomi; Obana, Eiichiro; Hayashi, Hirofumi; Noguchi, Takehiro

    2013-04-01

    Erosion is a particle-based phenomenon, yet most of current understanding and modelling of this process is based on bulk measurements rather than the movement of individual particles. Difficulties with measuring particle motions in dynamically changing conditions are being overcome with the application of two new technologies - particle imaging velocimetry (PIV) and radio frequency identification (RFID). It is thus possible to evaluate the entrainment, transport and deposition of individual particles and these data can be used to parameterize and to test particle-based modelling of the particle-based process. Both PIV and RFID tagging have been used in laboratory experiments to evaluate the detachment process by raindrops on bare surfaces and in shallow flows using rainfall simulation. The results suggest that the processes are more complex than hitherto thought with multiple detachment and transfer mechanisms. Because both mechanisms affect travel distance, they affect the ways in which estimates of soil erosion can be scaled from plot to hillslope and catchment scales. To evaluate movements at larger scales, we have also used RFID-tagged particles in field settings to look at sediment transfers following the Fukushima accident in Japan, 2011. A marker-in-cell model (MAHLERAN-MiC) has been developed to enable the laboratory results to be upscaled and tested in a field setting. Markers (representing sediment particles), containing sediment-property information, are initially distributed on a cellular grid. A cellular model is used to set up the boundary conditions and determine the hydrology and hydraulics on the hillslope. The markers are then moved through the grid according to these properties. This technique combines the advantages of Eulerian and Lagrangian methods while avoiding the shortcomings of each (computational efficiency vs. accuracy). The model simulates all the processes of detachment and transport; raindrop detachment and transport, interrill

  7. The influence of forest roads on runoff generation and soil erosion -- an assessment based on small scale rainfall simulation

    NASA Astrophysics Data System (ADS)

    Zemke, Julian J.

    2016-04-01

    In the course of forestry operations such as pruning and harvesting, a dense network of forest roads and skid trails has to be established. Due to mostly insufficient soil protective measures, the frequent overpassing of previously undisturbed topsoil with heavy forestry equipment on skid trails generates severe soil compaction. On persistent forest roads, the constructional layout and fortification also cause an increase of soil density. As a result of soil compaction, infiltration capacities are significantly reduced. Therefore, the affected areas tend to generate overland flow much quicker than undisturbed soil and differ considerably from the adjacent forest topsoil. As a consequence, decentral water retention on the watershed scale can be affected, if the road network is too dense and/or covers too much of the catchment's surface. Another consequence is the increase of soil erosion rates caused by erosive overland flows and the removal of vegetation cover on roads and skid trails. Again, the road and path surfaces differ significantly from adjacent forest soils where soil erosion rates normally tend to be equal or less than the soil renewal rates. To quantify the influence of forest roads and skid trails on runoff generation and soil erosion rates in a forested catchment area, rainfall simulations were carried out. A small scale rainfall simulator with a plot area of 0,64 m2 was used to simulate rainfall events with an intensity of 45 mm/h, a duration of 3 x 30 minutes and a kinetic energy of 4,6 J/m2*mm. Overland flow and eroded material were collected in a high temporal resolution of 1 minute. The sampled roads and skid trails were differentiated and categorized according to their constructional layout. Beyond that, rutted and unrutted road areas were distinguished. To obtain a benchmark for natural soil characteristics, undisturbed forest soils were also examined. The results show a significant influence of traffic induced soil compaction on the

  8. Wind erosion reduces soil organic carbon sequestration falsely indicating ineffective management practices

    NASA Astrophysics Data System (ADS)

    Chappell, Adrian; Baldock, Jeffrey A.

    2016-09-01

    Improved management of agricultural land has the potential to reduce greenhouse gas emissions and to reduce atmospheric CO2 via soil carbon sequestration. However, SOC stocks are reduced by soil erosion which is commonly omitted from calculations of crop production, C cycling, C sequestration and C accounting. We used fields from the wind eroded dryland cropping region of Western Australia to demonstrate the global implications for C sequestration and C accounting of omitting soil erosion. For the fields we previously estimated mean net (1950s-1990) soil erosion of 1.2 ± 1.0 t ha-1 y-1. The mean net (1990-2013) soil erosion increased by nearly four times to 4.4 ± 2.1 t ha-1 y-1. Conservation agriculture has evidently not reduced wind erosion in this region. The mean net (1990-2013) SOC erosion was up to 0.2 t C ha-1 y-1 across all sampled fields and similar to measured sequestration rates in the region (up to 0.5 t C ha-1 y-1; 10 years) for many management practices recommended for building SOC stocks. The minimum detectable change (MDC; 10 years) of SOC without erosion was up to 0.2 t C ha-1 y-1 whilst the MDC of SOC with erosion was up to 0.4 t C ha-1 y-1. These results illustrate the generally applicable outcome: (i) if SOC erosion is equal to (or greater than) the increase in SOC due to management practices, the change will not be detectable (or a loss will be evident); (ii) without including soil erosion in SOC sequestration calculations, the monitoring of SOC stocks will lead to, at best the inability to detect change and, at worst the false impression that management practices have failed to store SOC. Furthermore, continued omission of soil erosion in crop production, C accounting and C sequestration will most likely undermine confidence in policy designed to encourage adoption of C farming and the attendant benefits for soil stewardship and food security.

  9. Soil organic carbon mobilization by interrill erosion: Insights from size fractions

    NASA Astrophysics Data System (ADS)

    Wang, Zhengang; Govers, Gerard; Oost, Kristof Van; Clymans, Wim; Putte, An Van; Merckx, Roel

    2013-06-01

    mobilized by interrill erosion are often highly enriched in soil organic carbon (SOC) in comparison to source soils. This selectivity may lead to the preferential mobilization of SOC with specific properties, e.g., SOC that is especially susceptible to decomposition. This may then have important implications with respect to the role of soil erosion in the global carbon cycle. We addressed this issue by investigating the behavior of different SOC components in field rainfall simulation experiments on arable fields in loess-derived soils. We characterized the mobilization of mineral-bound organic carbon (MOC) and particulate organic carbon (POC) by interrill erosion using size fractionation and we used the C:N ratio as a tracer variable to determine the composition of the SOC in eroded sediments. MOC was found to be preferentially mobilized by interrill erosion in comparison to POC. The enrichment ratio (i.e., the ratio of the concentration of a soil constituent in the eroded sediment to its concentration in the original soil) of MOC decreased with increasing sediment concentration. The enrichment ratio of POC displayed a similar pattern to that of MOC but enrichment was less pronounced. Furthermore, sediments were found to be enriched in fine POC while they were impoverished with respect to coarse POC. The selective MOC mobilization together with the dominance of MOC in the total SOC pool in the soil explained the dominance of MOC in interrill eroded sediment. The fact that it is mainly MOC that is mobilized by interrill erosion implies that the SOC in the interrill eroded sediments is on average at least as recalcitrant than that in the source soils which may have important implications for the fate of the mobilized SOC. In order to understand the role of soil erosion in C cycling, MOC and POC need to be considered separately not only because they are chemically different but also because of their different behaviors with respect to geomorphic processes.

  10. Mediterranean valleys revisited: Linking soil erosion, land use and climate variability in the Northern Levant

    NASA Astrophysics Data System (ADS)

    Casana, Jesse

    2008-10-01

    This paper presents results of geomorphological and archaeological investigations undertaken in several small drainage basins in the Jebel al-Aqra region of southern Turkey. By focusing intensive archaeological settlement survey in basins where securely dated sequences of sedimentary valley fills have been recorded, spatially and temporally linked, high-resolution records of land use and soil erosion have been generated. Sedimentary data show that throughout most of the Holocene, floodplains remained rather stable, allowing deep soils to form. But in the past two millennia, probably from AD 150-700, a phase of severe soil erosion was initiated and resulted in the deposition of 3.5-5.0 m of alluvial sediments on valley floors. Archaeological and historical evidence suggest that while these areas were occupied by agrarian communities since at least 2800 BC, nearly three millennia of cultivation during the Bronze and Iron Ages had relatively little effect on soil erosion. The intensification of settlement throughout the region and the conversion of upland areas to intensive agricultural production during the Hellenistic, Roman and late Roman periods (300 BC-AD 650), however, created the necessary preconditions for severe soil erosion to occur. These data are compared against modern and paleoclimate studies of the eastern Mediterranean, which show an extremely variable precipitation regime and the effects that it can have on erosion. A 400-year lag between the initial settlement of upland areas and the first evidence of soil erosion suggest that it may have been the intersection of extreme precipitation events with particular land use conditions of the Roman and late Roman periods which worked together to drive soil erosion.

  11. Spatio-temporal analysis of soil erosion risk and runoff using AnnAGNPS

    NASA Astrophysics Data System (ADS)

    Yeshaneh, Eleni; Wagner, Wolfgang; Blöschl, Günter

    2014-05-01

    Soil erosion is one form of land degradation in Ethiopia deteriorating the fertility and productivity of the land. This fact indicates the need to delineate high erosion risk areas for appropriate soil and conservation measures. Land use/cover change is one of the important factors in soil erosion. This study attempts test and implement AnnAGNPS model to estimate the spatio-temporal patterns of soil erosion and runoff associated with land use changes in the past 50 years in the 9900 ha upstream part of the Koga catchment. High erosion risk areas will then be delineated for simulation of the appropriate soil and water conservation measures that would reduce the soil loss. The study is based on two years high temporal resolution data on discharge, sediment, and rain fall accompanied by historical land use/cover data generated from satellite imagery. In addition, it uses several documented physical parameters of the study area. The Koga catchment is one of the agriculture dominated typical catchments in the North Western Ethiopian highlands with high population density that lead to increased pressure on natural resources.

  12. Radiocesium wash-off associated with soil erosion from various land uses after the Fukushima Dai-ichi NPP accident

    NASA Astrophysics Data System (ADS)

    Wakiyama, Yoshifumi; Onda, Yuichi; Yoshimura, Kazuya; Kato, Hiroaki; Konoplev, Alexei; Zheleznyak, Mark

    2014-05-01

    Soil erosion is the initial process which drives radiocesium into the aquatic systems and therefore the quantification of radiocesium wash-off associated with soil erosion is indispensable for mitigating the risks. This study presents two year's observation of soil erosion and radiocesium wash-off to quantify differences in radiocesium behavior in various land uses. Seven runoff plots were established in four landscapes; uncultivated farmland (Farmland A1, Farmland B1), cultivated farmland (Farmland A2, Farmland B2), grassland (Grassland A, Grassland B) and Japanese cedar forest (Forest) in Kawamata town, an area affected by the Fukushima Dai-ichi Nuclear Power Plant accident. The discharged sediments were collected approximately every two weeks. In laboratories, collected sediments were dried and weighed for calculating soil erosion rates (kg m-2) and served for measurements of radiocesium concentration (Bq kg-1) with HPGe detectors. The erosivity factor of the Universal Soil Loss Equation (R-factor: MJ mm ha-1 hr-1 yr-1) was calculated based on the data of precipitation. Standardized soil erosion rates (kg m-2 MJ-1 mm-1 ha hr yr), observed soil erosion rates divided by R-factor, was 1.8 × 10-4 in Farmland A1, 6.0 × 10-4 in Farmland A2, 1.5 × 10-3 in Farmland B1, 8.3 × 10-4 in Farmland B2, 9.6 × 10-6 in Grassland A, 5.9 × 10-6 in Grassland B and 2.3 × 10-6 in Forest. These erosion rates were basically proportional to their vegetation cover of soil surfaces except for cultivated farmlands. Concentrations of Cs-137 in eroded sediments basically depended on the local deposition of Cs-137 and varied enormously with ranging several orders of magnitude in all the landscapes. For the observation period of time decreasing trends in concentrations of Cs-137 in eroded sediments were not obvious. To compare these results with those of Chernobyl, we calculated normalized 'solid' wash-off coefficient (m2 g-1) with dividing the mean total concentration of Cs-137 in

  13. Fuzzy-based dynamic soil erosion model (FuDSEM): Modelling approach and preliminary evaluation

    NASA Astrophysics Data System (ADS)

    Cohen, Sagy; Svoray, Tal; Laronne, Jonathan B.; Alexandrov, Yulia

    2008-07-01

    SummarySoil erosion models have advanced in recent years, by becoming more physically-based, with better representation of spatial patterns. Despite substantial progress, fundamental difficulties in catchment scale applications have been widely reported. In this paper, we introduce a new catchment scale soil erosion model. The model is designed for catchment interface and management purposes by: (1) using relatively common input data; (2) having a modular model structure; and (3) a clear and easily interpretable output analysis, by producing possibility or potential, rather than quantitative erosion maps. The model (named: FuDSEM; fuzzy-based dynamic soil erosion model) is spatially explicit and temporally dynamic and is formalized and based on fuzzy-logic equations. FuDSEM was initially evaluated on a small data-rich catchment and was found well calibrated. It was then implemented on a medium-sized heterogeneous catchment in central Israel. Initial evaluations of the medium-scale model predictions were conducted by: (1) comparison of FuDSEM runoff predictions against measured runoff from five hydrological stations and (2) a site specific evaluation of the FuDSEM multi-year erosion prediction in two sub-catchments. FuDSEM was compared with two other erosion models (a temporally static version of itself and a known physically-based model). The results show the advantages of FuDSEM over the other two models in evaluating the relative distribution of erosion, thereby emphasizing the benefits of its temporally dynamic and fuzzy structure.

  14. Issues of upscaling in space and time with soil erosion models

    NASA Astrophysics Data System (ADS)

    Brazier, R. E.; Parsons, A. J.; Wainwright, J.; Hutton, C.

    2009-04-01

    Soil erosion - the entrainment, transport and deposition of soil particles - is an important phenomenon to understand; the quantity of soil loss determines the long term on-site sustainability of agricultural production (Pimental et al., 1995), and has potentially important off-site impacts on water quality (Bilotta and Brazier, 2008). The fundamental mechanisms of the soil erosion process have been studied at the laboratory scale, plot scale (Wainwright et al., 2000), the small catchment scale (refs here) and river basin scale through sediment yield and budgeting work. Subsequently, soil erosion models have developed alongside and directly from this empirical work, from data-based models such as the USLE (Wischmeier and Smith, 1978), to ‘physics or process-based' models such as EUROSEM (Morgan et al., 1998) and WEPP (Nearing et al., 1989). Model development has helped to structure our understanding of the fundamental factors that control soil erosion process at the plot and field scale. Despite these advances, however, our understanding of and ability to predict erosion and sediment yield at the same plot, field and also larger catchment scales remains poor. Sediment yield has been shown to both increase and decrease as a function of drainage area (de Vente et al., 2006); the lack of a simple relationship demonstrates complex and scale-dependant process domination throughout a catchment, and emphasises our uncertainty and poor conceptual basis for predicting plot to catchment scale erosion rates and sediment yields (Parsons et al., 2006b). Therefore, this paper presents a review of the problems associated with modelling soil erosion across spatial and temporal scales and suggests some potential solutions to address these problems. The transport-distance approach to scaling erosion rates (Wainwright, et al., 2008) is assessed and discussed in light of alternative techniques to predict erosion across spatial and temporal scales. References Bilotta, G.S. and

  15. Modeling soil erosion impact of rangeland disturbance using the Rangeland Hydrology and Erosion Model (RHEM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Disturbance on rangeland such as fire and tree encroachment can increase overland flow erosion rate by increasing the likelihood of concentrated flow formation on a more erodible surface. In this study, we made advancements to RHEM by developing a new version of the model to predict concentrated flo...

  16. Soil erosion predictions from upland areas – a discussion of selected RUSLE2 advances and needs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Obtaining more accurate soil loss estimates from upland areas is important for improving management practices on agricultural fields. Much of the soil erosion prediction research of the last 25 years has been concerned with this goal. The most widely used predictive relationships have been the Unive...

  17. Morphodynamics of headcut development and soil erosion in upland concentrated flows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In agricultural regions, gully erosion is now recognized as becoming a dominant source of soil loss, and the development and upstream migration of headcuts is critical to the initiation, incision, and dissection of these upland areas. The present investigation sought to examine the effect of soil t...

  18. Assessing impact of climate change on soil erosion and conservation in southern Loess Plateau of China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As clearly stated in a special report from the Soil and Water Conservation Society, the potential for projected climate changes to increase the risk of soil erosion and related environmental consequences is clear, but the potential damages are not. There is a need to assess the potential damages acr...

  19. Soil erosion modelling of the Mediterranean basin in the context of land use and climate changes.

    NASA Astrophysics Data System (ADS)

    Cerdan, Olivier; Desprats, Jean-François; Fouché, Julien; Le Bissonnais, Yves; Cheviron, Bruno; Simonneaux, Vincent; Raclot, Damien; Mouillot, Florent

    2010-05-01

    Hydric erosion is one of the major causes of soil degradation. It results from the interaction of several parameters which vary in space and time. Global warming and the land use changes expected during the 21st century are going to influence the soils deterioration and the erosion processes. In order to protect the soil resource under the current bioclimatic context and prevent the future consequences, it is essential to apprehend the erosion risk. Many studies developed the soil erosion risk modelling at various scales from regional to European scale. The MESOEROS project is the first which aims to understand the soil loss risk on the whole Mediterranean basin for the current climate context and also for the predicting climate changes expected for the 21st century. Two models are used: MESALES (expert rules model) and PESERA (physical based model). Both provide the soil erosion risk into five classes. Model inputs, soils properties (crusting and erodibility), climate data, DEM and land use data, come from the most recent and validated datasets, homogenised on the whole study area. After being calibrated with watersheds data and the PESERA modelling on Europe, the two modelling results are analysed. Both MESALES and PESERA present an erosion risk contrast around the Mediterranean basin. MESALES estimates Italia, Andalusia, Catalan and Aragon regions, western part of Greece and Balkan region as threatened areas while PESERA models the arable region of Castellan y Leon, Near East and the high atlas range in Morocco as subjected to an erosion risk. The two methods model parts of northern Morocco, centre and European part of Turkey, Lebanon and northern Portugal at risk while southern France, Libyan coasts and southern Greece are never threatened. Analyses of the parameter influences on the models and the modelling validation allow understanding the integration of climate change on modelling results. MESALES and PESERA point out an evolution of the soil erosion risk

  20. Deterministic modeling of future soil erosion within a framework of uncertain climate change and unpredictable producer adaptation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservationists are concerned that climate change in the Southern Great Plains may result in increased soil erosion. Effectiveness of soil conservation practices under a changing climate is assessed by application of the changed climate characteristics to a soil erosion model. The issue at hand is...

  1. Understanding soil erosion impacts in temperate agroecosystems: bridging the gap between geomorphology and soil ecology using nematodes as a model organism

    NASA Astrophysics Data System (ADS)

    Baxter, C.; Rowan, J. S.; McKenzie, B. M.; Neilson, R.

    2013-11-01

    Soil is a key asset of natural capital, providing a myriad of goods and ecosystem services that sustain life through regulating, supporting and provisioning roles, delivered by chemical, physical and biological processes. One of the greatest threats to soil is accelerated erosion, which raises a natural process to unsustainable levels, and has downstream consequences (e.g.~economic, environmental and social). Global intensification of agroecosystems is a recognised major cause of soil erosion which, in light of predicted population growth and increased demand for food security, will continue or increase. Transport and redistribution of biota by soil erosion has hitherto been ignored and thus is poorly understood. With the move to sustainable intensification this is a key knowledge gap that needs to be addressed. Here we highlight the erosion-energy and effective-erosion-depth continuum in soils, differentiating between different forms of soil erosion, and argue that nematodes are an appropriate model taxa to investigate impacts of erosion on soil biota across scales. We review the different known mechanisms of soil erosion that impact on soil biota in general, and nematodes in particular, and highlight the few detailed studies, primarily from tropical regions, that have considered soil biota. Based on the limited literature and using nematodes as a model organism we outline future research priorities to initially address the important interrelationships between soil erosion processes and soil biota.

  2. The history of soil erosion: Interpreting historical sources, buried soils and colluvial sediments as archives of past soil erosion and human-environment interactions in the Longue Durée

    NASA Astrophysics Data System (ADS)

    Dotterweich, Markus

    2015-04-01

    Soil erosion threatens the environment and the sustainability of agricultural practices since the earliest societies started modifying their natural environment in the Neolithic. Almost all farming-based cultures in the world, from large civilizations to peasant groups on little islands, have suffered from soil erosion by water. The amounts of soil erosion varied largely through time and space, and extreme events have left a wide variety of imprints on the landscape over millennia. Eroded hillslopes and gullies, deposited sediments in sinks like lakes, footslopes, valleys, floodplains, and river deltas are geomorphic legacies that have been linked to changes in land use and climate by many studies during the last decades. However, a standardized analysis and interpretation of these geomorphic legacies is problematic because of the variety of methodological approaches and the nonlinearity between soil erosion, climate, and land use. Cascading effects, land use structures, soil management, soil conservation strategies, and long-term system changes have produced different signals over time. Historical records are crucial and an invaluable source to provide alternative proxies about soil erosion in the past. Direct observations of individual soil erosion events may restrict the deposition of a distinct sediment package to a certain time span. They also expand the range of alternative interpretations, particularly with respect to the long-term effects of soil erosion to ecosystem services and socioeconomic processes. However, historical records also need critical analyses regarding their origin, intention, and quality. They were often created in the context of personal interests or political issues rather than being based on scientific facts; and it is often unclear if they represent certain events, narratives, or vague assumptions. This presentation will present and discuss examples of geomorphic evidences and historical records of past soil erosion for the deciphering

  3. Hillslope soil erosion estimated from aerosol concentrations, North Halawa Valley, Oahu, Hawaii

    USGS Publications Warehouse

    Hill, B.R.; Fuller, C.C.; DeCarlo, E.H.

    1997-01-01

    Concentrations of aerosolic quartz and 137Cs were used to estimate rates of hillslope soil erosion during 1990-91 in the North Halawa Valley on the island of Oahu, Hawaii. Fluvial transport of quartz was estimated to be 6.1 Mg in 1990 and 14.9 Mg in 1991. Fluvial transport of 137Cs from North Halawa Valley was estimated to be 1.29 ?? 109 pCi in 1991. Results were used with quartz contents, 137Cs activities, and bulk densities of hillslope soils to compute rates of basinwide hillslope soil erosion ranging from 0.1 to 0.3 mm yr-1. These rates are within the range of previous estimates of denudation computed for drainage basins on Oahu. The aerosol-concentration approach, therefore, is a useful method for assessing basinwide soil erosion.

  4. Human impact on erosion and burial of soil carbon through time

    NASA Astrophysics Data System (ADS)

    Hoffmann, Thomas; Strauch, Adrian; Amelung, Wulf; Gerlach, Renate; Bornemann, Ludger; Lang, Andreas

    2015-04-01

    The effects of soil erosion on atmospheric carbon is governed by three key mechanisms that are i) the replacement of soil organic carbon (SOC) at eroding sites, ii) the mineralization of SOC during erosion and transport and iii) the stability of buried SOC at depositional sites. Markedly different assumptions have been made about the relative importance of the key mechanisms, resulting in a global release of 1 Pg C yr-1 to a global uptake of 1 Pg C yr-1. Here we present results of a sediment-associated carbon budget in a small headwater catchment in Germany, to highlight the importance of the timescale in controlling the relative importance of the key mechanisms. Therefore, we estimate the loss of SOC through land use change from forests to arable land and compare it with SOC losses at degraded sites and burial of SOC in colluvial deposits. Our results show that the transition of forest to arable land (without erosion and deposition of soils and sediments) resulted in a rapid loss of SOC from 11.8 kg C m-2 to 7.2 kg C m-2 in our study site. Eroded sites are characterized by carbon stocks of 6.9 kg C m-2 compared to depositional sites with 27.9 kg C m-2. Thus the combined effect of soil erosion and deposition results in a slow net withdrawal of atmospheric CO2, which compensates land use driven losses. We show that the net effect of SOC degradation and burial depends on the rate of soil erosion and time since the erosion commenced. Given the erosion history in the study site, the removal of SOC through land use change will be compensated after approx. 120 years of erosion and deposition.

  5. Human impact on erosion and burial of soil carbon through time

    NASA Astrophysics Data System (ADS)

    Hoffmann, Thomas; Amelung, Wulf; Bornemann, Ludger; Gerlach, Renate; Lang, Andreas

    2016-04-01

    The effects of soil erosion on atmospheric carbon is governed by three key mechanisms that are i) the replacement of soil organic carbon (SOC) at eroding sites, ii) the mineralization of SOC during erosion and transport and iii) the stability of buried SOC at depositional sites. Markedly different assumptions have been made about the relative importance of the key mechanisms, resulting in a global release of 1 Pg C/a to a global uptake of 1 Pg C/a. Here we present results of a sediment-associated carbon budget in a small headwater catchment in Germany, to highlight the importance of the timescale in controlling the relative importance of the key mechanisms. Therefore, we estimate the loss of SOC through land use change from forests to arable land and compare it with SOC losses at degraded sites and burial of SOC in colluvial deposits. Our results show that the transition of forest to arable land (without erosion and deposition of soils and sediments) resulted in a rapid loss of SOC from 11.8 kg C/m² to 7.2 kg C/m² in our study site. Eroded sites are characterized by carbon stocks of 6.9 kg C/m² compared to depositional sites with 27.9 kg C/m². Thus the combined effect of soil erosion and deposition results in a slow net withdrawal of atmospheric CO2, which compensates land use driven losses. We show that the net effect of SOC degradation and burial depends on the rate of soil erosion and time since the erosion commenced. Given the erosion history in the study site, the removal of SOC through land use change will be compensated after approx. 120 years of erosion and deposition.

  6. Seasonality of soil erosion under mediterranean conditions at the Alqueva Dam watershed.

    PubMed

    Ferreira, Vera; Panagopoulos, Thomas

    2014-07-01

    The Alqueva reservoir created the largest artificial lake of Western Europe in 2010. Since then, the region has faced challenges due to land-use changes that may increase the risk of erosion and shorten the lifetime of the reservoir, increasing the need to promote land management sustainability. This paper investigates the aspect of seasonality of soil erosion using a comprehensive methodology that integrates the Revised Universal Soil Loss Equation (RUSLE) approach, geographic information systems, geostatistics, and remote-sensing. An experimental agro-silvo pastoral area (typical land-use) was used for the RUSLE factors update. The study confirmed the effect of seasonality on soil erosion rates under Mediterranean conditions. The highest rainfall erosivity values occurred during the autumn season (433.6 MJ mm ha(-1) h(-1)), when vegetation cover is reduced after the long dry season. As a result, the autumn season showed the highest predicted erosion (9.9 t ha(-1)), contributing 65 % of the total annual erosion. The predicted soil erosion for winter was low (1.1 t ha(-1)) despite the high rainfall erosivity during that season (196.6 MJ mm ha(-1) h(-1)). The predicted annual soil loss was 15.1 t ha(-1), and the sediment amount delivery was 4,314 × 10(3) kg. Knowledge of seasonal variation would be essential to outline sustainable land management practices. This model will be integrated with World Overview of Conservation Approaches and Technologies methods to support decision-making in that watershed, and it will involve collaboration with both local people and governmental institutions. PMID:24794193

  7. Seasonality of Soil Erosion Under Mediterranean Conditions at the Alqueva Dam Watershed

    NASA Astrophysics Data System (ADS)

    Ferreira, Vera; Panagopoulos, Thomas

    2014-07-01

    The Alqueva reservoir created the largest artificial lake of Western Europe in 2010. Since then, the region has faced challenges due to land-use changes that may increase the risk of erosion and shorten the lifetime of the reservoir, increasing the need to promote land management sustainability. This paper investigates the aspect of seasonality of soil erosion using a comprehensive methodology that integrates the Revised Universal Soil Loss Equation (RUSLE) approach, geographic information systems, geostatistics, and remote-sensing. An experimental agro-silvo pastoral area (typical land-use) was used for the RUSLE factors update. The study confirmed the effect of seasonality on soil erosion rates under Mediterranean conditions. The highest rainfall erosivity values occurred during the autumn season (433.6 MJ mm ha-1 h-1), when vegetation cover is reduced after the long dry season. As a result, the autumn season showed the highest predicted erosion (9.9 t ha-1), contributing 65 % of the total annual erosion. The predicted soil erosion for winter was low (1.1 t ha-1) despite the high rainfall erosivity during that season (196.6 MJ mm ha-1 h-1). The predicted annual soil loss was 15.1 t ha-1, and the sediment amount delivery was 4,314 × 103 kg. Knowledge of seasonal variation would be essential to outline sustainable land management practices. This model will be integrated with World Overview of Conservation Approaches and Technologies methods to support decision-making in that watershed, and it will involve collaboration with both local people and governmental institutions.

  8. Runoff and soil erosion for an undisturbed tropical woodland in the Brazilian Cerrado

    NASA Astrophysics Data System (ADS)

    Oliveira, Paulo Tarso S.; Nearing, Mark; Wendland, Edson

    2015-04-01

    The Brazilian Cerrado is a large and important economic and environmental region that is experiencing major loss of its natural landscapes due to pressures of food and energy production, which has caused large increases in soil erosion. However the magnitude of the soil erosion increases in this region is not well understood, in part because scientific studies of surface runoff and soil erosion are scarce or nonexistent in undisturbed Cerrado vegetation. In this study we measured natural rainfall-driven rates of runoff and soil erosion for an undisturbed tropical woodland classified as "cerrado sensu stricto denso" and bare soil to compute the Universal Soil Loss Equation (USLE) cover and management factor (C-factor) to help evaluate the likely effects of land use change on soil erosion rates. Replicated data on precipitation, runoff, and soil loss on plots (5 x 20 m) under bare soil and cerrado were collected for 55 erosive storms occurring in 2012 and 2013. The measured annual precipitation was 1247.4 mm and 1113.0 mm for 2012 and 2013, resulting in a rainfall erosivity index of 4337.1 MJ mm ha-1 h-1 and 3546.2 MJ mm ha-1 h-1, for each year respectively. The erosive rainfall represented 80concentrated in the wet season, which generally runs from October through March. In the plots on bare soil, the runoff coefficient for individual rainfall events (total runoff divided by total rainfall) ranged from 0.003 to 0.860 with an average value and standard deviation of 0.212 ± 0.187. Moreover, the runoff coefficient found for the bare soil plots (~20infiltration capacity. In forest areas the leaf litter and the more porous soil tend to promote the increase of infiltration and water storage, rather than rapid overland flow. Indeed, runoff coefficients ranged from 0.001 to 0.030 with an average of less than 1under undisturbed cerrado. The soil losses measured under bare soil and cerrado were 15.68 t ha-1yr-1 and 0.24 t ha-1 yr-1 in 2012, and 14.82 t ha-1 yr-1, 0.11 t ha-1

  9. Erosion and deposition in tidal marshes revisited by accounting for soil creep

    NASA Astrophysics Data System (ADS)

    Mariotti, G.

    2015-12-01

    Channels regulate the sediment dynamics of tidal marshes, affect the capacity of marsh platforms to keep pace with sea level rise and can contribute to the loss of the low marsh, a critical area for nutrient cycling and ecosystem services. A puzzling aspect of marsh dynamics is the occurrence of slumping on the channel banks despite the absence of channel widening and migration. An apparently unrelated conundrum is why vertical accretion rates on the low marsh adjacent to channels are often higher than the rate of relative sea level rise: this sedimentation excess should not occur in a regime of equilibrium or in a regime of accelerated sea level rise. Here I suggest that bank erosion and sedimentation surplus are linked and can be explained by soil creep, the process by which soil is moved downslope by gravity. A novel model for a channel-platform cross section predicts an equilibrium state where the sedimentation surplus on the channel banks is transferred by creep toward the channel, where an erosional surplus and a suspend load transport toward the bank close the sediment budget. This model predicts that bank slumping can occur even if marshes are in equilibrium with sea level rise. As a consequence slumping is not an unequivocal indicator of ongoing marsh loss. The model also predicts that, at equilibrium, sedimentation rates adjacent to channels are higher than the rate of sea level rise. This implies that a sedimentation surplus is not a sign of resilience to sea level rise acceleration. The framework proposed by the model will affect how erosion and deposition measurements adjacent to marsh channels are interpreted.

  10. Interrill erosion as an index of mined land soil erodibility

    SciTech Connect

    Lang, K.J.; Schroeder, S.A.; Prunty, L.D.; Disrud, L.D.

    1983-01-01

    A rainfall simulation technique was used to evaluate the influence of slope steepness, mulch rate and antecedent soil moisture on runoff, splash, soil loss in runoff and the primary particle size composition of soil in splash and sediment from interrill areas on two western North Dakota mined land soils. 21 references, 4 figures, 4 tables.

  11. Soil Erosion map of Europe based on high resolution input datasets

    NASA Astrophysics Data System (ADS)

    Panagos, Panos; Borrelli, Pasquale; Meusburger, Katrin; Ballabio, Cristiano; Alewell, Christine

    2015-04-01

    Modelling soil erosion in European Union is of major importance for agro-environmental policies. Soil erosion estimates are important inputs for the Common Agricultural Policy (CAP) and the implementation of the Soil Thematic Strategy. Using the findings of a recent pan-European data collection through the EIONET network, it was concluded that most Member States are applying the empirical Revised Universal Soil Loss Equation (RUSLE) for the modelling soil erosion at National level. This model was chosen for the pan-European soil erosion risk assessment and it is based on 6 input factors. Compared to past approaches, each of the factors is modelled using the latest pan-European datasets, expertise and data from Member states and high resolution remote sensing data. The soil erodibility (K-factor) is modelled using the recently published LUCAS topsoil database with 20,000 point measurements and incorporating the surface stone cover which can reduce K-factor by 15%. The rainfall erosivity dataset (R-factor) has been implemented using high temporal resolution rainfall data from more than 1,500 precipitation stations well distributed in Europe. The cover-management (C-factor) incorporates crop statistics and management practices such as cover crops, tillage practices and plant residuals. The slope length and steepness (combined LS-factor) is based on the first ever 25m Digital Elevation Model (DEM) of Europe. Finally, the support practices (P-factor) is modelled for first time at this scale taking into account the 270,000 LUCAS earth observations and the Good Agricultural and Environmental Condition (GAEC) that farmers have to follow in Europe. The high resolution input layers produce the final soil erosion risk map at 100m resolution and allow policy makers to run future land use, management and climate change scenarios.

  12. A multi-radionuclide approach to evaluate the suitability of (239+240)Pu as soil erosion tracer.

    PubMed

    Meusburger, Katrin; Mabit, Lionel; Ketterer, Michael; Park, Ji-Hyung; Sandor, Tarjan; Porto, Paolo; Alewell, Christine

    2016-10-01

    Fallout radionuclides have been used successfully worldwide as tracers for soil erosion, but relatively few studies exploit the full potential of plutonium (Pu) isotopes. Hence, this study aims to explore the suitability of the plutonium isotopes (239)Pu and (240)Pu as a method to assess soil erosion magnitude by comparison to more established fallout radionuclides such as (137)Cs and (210)Pbex. As test area an erosion affected headwater catchment of the Lake Soyang (South Korea) was selected. All three fallout radionuclides confirmed high erosion rates for agricultural sites (>25tha(-1)yr(-1)). Pu isotopes further allowed determining the origin of the fallout. Both (240)Pu/(239)Pu atomic ratios and (239+240)Pu/(137)Cs activity ratios were close to the global fallout ratio. However, the depth profile of the (239+240)Pu/(137)Cs activity ratios in undisturbed sites showed lower ratios in the top soil increments, which might be due to higher migration rates of (239+240)Pu. The activity ratios further indicated preferential transport of (137)Cs from eroded sites (higher ratio compared to the global fallout) to the depositional sites (smaller ratio). As such the (239+240)Pu/(137)Cs activity ratio offered a new approach to parameterize a particle size correction factor that can be applied when both (137)Cs and (239+240)Pu have the same fallout source. Implementing this particle size correction factor in the conversion of (137)Cs inventories resulted in comparable estimates of soil loss for (137)Cs and (239+240)Pu. The comparison among the different fallout radionuclides highlights the suitability of (239+240)Pu through less preferential transport compared to (137)Cs and the possibility to gain information regarding the origin of the fallout. In conclusion, (239+240)Pu is a promising soil erosion tracer, however, since the behaviour i.e. vertical migration in the soil and lateral transport during water erosion was shown to differ from that of (137)Cs, there is a clear

  13. Influence of Llamas, Horses, and Hikers on Soil Erosion from Established Recreation Trails in Western Montana, USA

    PubMed

    Deluca; Patterson Iv WA; Freimund; Cole

    1998-03-01

    / Various types of recreational traffic impact hiking trails uniquely and cause different levels of trail degradation; however, trail head restrictions are applied similarly across all types of packstock. The purpose of this study was to assess the relative physical impact of hikers, llamas, and horses on recreational trails. Horse, llama, and hiker traffic were applied to 56 separate plots on an existing trail at Lubrecht Experimental Forest in western Montana. The traffic was applied to plots at intensities of 250 and 1000 passes along with a no-traffic control under both prewetted and dry trail conditions. Soil erosion potential was assessed by sediment yield and runoff (using a Meeuwig type rainfall simulator), changes in soil bulk density, and changes in soil surface roughness. Soil moisture, slope, and rainfall intensity were recorded as independent variables in order to evaluate the extent that they were held constant by the experimental design. Horse traffic consistently made more sediment available for erosion from trails than llama, hiker, or no traffic when analyzed across wet and dry trail plots and high and low intensity traffic plots. Although total runoff was not significantly affected by trail user, wet trail traffic caused significantly greater runoff than dry trail traffic. Llama traffic caused a significant increase in sediment yield compared to the control, but caused erosion yields not significantly different than hiker traffic. Trail traffic did not increase soil compaction on wet trails. Traffic applied to dry trail plots generally resulted in a significant decrease in soil bulk density compared to the control. Decreased soil bulk density was negatively correlated with increased sediment yield and appeared to result in increased trail roughness for horse traffic compared to hiker or llama traffic. Differences described here between llama and horse traffic indicate that trail managers may want to consider managing packstock llamas independent

  14. Vulnerability of desert biological soil crusts to wind erosion: The influences of crust development, soil texture, and disturbance

    USGS Publications Warehouse

    Belnap, J.; Gillette, Dale A.

    1998-01-01

    Biological soil crusts, consisting of cyanobacteria, green algae, lichens, and mosses, are important in stabilizing soils in semi-arid and arid lands. Integrity of these crusts is compromised by compressional disturbances such as foot, vehicle, or livestock traffic. Using a portable wind tunnel, we found threshold friction velocities (TFVs) of undisturbed crusts well above wind forces experienced at these sites; consequently, these soils are not vulnerable to wind erosion. However, recently disturbed soils or soils with less well-developed crusts frequently experience wind speeds that exceed the stability thresholds of the crusts. Crustal biomass is concentrated in the top 3 mm of soils. Sandblasting by wind can quickly remove this material, thereby reducing N and C inputs from these organisms. This loss can result in reduced site productivity, as well as exposure of unprotected subsurface sediments to wind and water erosion. Actions to reduce impacts to these crusts can include adjustments in type, intensity, and timing of use.

  15. Quantitative comparison of initial soil erosion processes and runoff generation in Spanish and German vineyards.

    PubMed

    Rodrigo Comino, J; Iserloh, T; Lassu, T; Cerdà, A; Keestra, S D; Prosdocimi, M; Brings, C; Marzen, M; Ramos, M C; Senciales, J M; Ruiz Sinoga, J D; Seeger, M; Ries, J B

    2016-09-15

    The aim of this study was to enable a quantitative comparison of initial soil erosion processes in European vineyards using the same methodology and equipment. The study was conducted in four viticultural areas with different characteristics (Valencia and Málaga in Spain, Ruwer-Mosel valley and Saar-Mosel valley in Germany). Old and young vineyards, with conventional and ecological planting and management systems were compared. The same portable rainfall simulator with identical rainfall intensity (40mmh(-1)) and sampling intervals (30min of test duration, collecting the samples at 5-min-intervals) was used over a circular test plot with 0.28m(2). The results of 83 simulations have been analysed and correlation coefficients were calculated for each study area to identify the relationship between environmental plot characteristics, soil texture, soil erosion, runoff and infiltration. The results allow for identification of the main factors related to soil properties, topography and management, which control soil erosion processes in vineyards. The most important factors influencing soil erosion and runoff were the vegetation cover for the ecological German vineyards (with 97.6±8% infiltration coefficients) and stone cover, soil moisture and slope steepness for the conventional land uses. PMID:27265730

  16. Testing of the hydromechanical prediction model of soil erosion under the conditions of Georgia

    NASA Astrophysics Data System (ADS)

    Gogichaishvili, G. P.; Kirvalidze, D. R.; Gorjomeladze, O. L.

    2014-09-01

    A hydromechanical model for predicting water (rain-induced) soil erosion was tested on the experimental plots of the Research Institute of Tea and Subtropical Crops in Zendidi village (the Ajara Autonomous Republic) and the Sabashvili Institute of Soil Science, Agrochemistry, and Melioration in Khevi and Kitskhi villages (Upper Imeretia, Western Georgia). A comparison of factual and predicted values of rain-induced erosion for the plots with permanent black fallow showed that the model overestimated the average annual soil loss for the yellow-brown strongly eroded soil in Zendidi village by 23.22 t/ha (133%). This value ranged in different years from 18 to 1052%. For the plots with corn, the predicted value of annual erosion was by 16.94 t/ha higher than the factual value (overestimation of 488%). A comparison of factual and predicted values of rainfall erosion for the plots under sprinkling irrigation also showed that the predicted soil loss was higher than the factual one by 4.14-30.40 t/ha for corn, 6.76-11.14 t/ha for winter wheat, and 15.75-24.12 t/ha for the plots with stubble of winter wheat and barley. Thus, the hydromechanical model for predicting water erosion inadequately describes it under the conditions of Western Georgia and has to be refined.

  17. Accumulation of moisture and soil erosion in the territory of social vole ( Microtus socialis) settlements in the northern Caspian Lowland

    NASA Astrophysics Data System (ADS)

    Bykov, A. V.; Kolesnikov, A. V.; Kulakova, N. Yu.; Shabanova, N. P.

    2008-08-01

    In the clay semidesert of the Caspian Lowland, the surface runoff is transformed to soil runoff due to the presence of a system of social vole ( Microtus socialis Pall.) passageways in the soils that promotes the retention of soil moisture and prevents the development of soil erosion. A quantitative assessment of this process is given. We describe the mechanism of intense soil erosion arising after the disturbance of vole underground passageways responsible for the formation of specific relief elements and plant communities.

  18. The impact of agricultural soil erosion on the global carbon cycle

    USGS Publications Warehouse

    Van Oost, Kristof; Quine, T.A.; Govers, G.; De Gryze, S.; Six, J.; Harden, J.W.; Ritchie, J.C.; McCarty, G.W.; Heckrath, G.; Kosmas, C.; Giraldez, J.V.; Marques Da Silva, J.R.; Merckx, R.

    2007-01-01

    Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 petagram per year -1 to a sink of the same magnitude. By using caesium-137 and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced sink of atmospheric carbon equivalent to approximately 26% of the carbon transported by erosion. Based on this relationship, we estimated a global carbon sink of 0.12 (range 0.06 to 0.27) petagrams of carbon per year-1 resulting from erosion in the world's agricultural landscapes. Our analysis directly challenges the view that agricultural erosion represents an important source or sink for atmospheric CO2.

  19. Mound measurements - quantifying medium-term soil erosion under olive trees in Northern Jordan

    NASA Astrophysics Data System (ADS)

    Kraushaar, S.; Herrmann, N.; Ollesch, G.; Vogel, H.-J.; Siebert, C.

    2014-05-01

    Over the last few decades many quantitative erosion studies have revealed that olive orchard expansion and increased mechanization in southern European countries have led to increased soil erosion under olive trees. Consequently, these studies have suggested different methods of mitigation. In light of the 2014 European trading zone expansion to countries east and south of the Mediterranean, a further intensification of olive plantations is postulated to meet market demands. To attain first medium-term estimates of erosion in Northern Jordan and its driving factors, a new method measuring olive mounds was implemented. Seven fields with clearly erosive structures were chosen throughout the Wadi Al-Arab catchment in Northern Jordan. Topographic measurements were used to reconstruct the historical and recent surface level and calculate the volume eroded since the planting of the trees. A total of 81 bulk density measurements and 14 tree cores allowed the estimation of the soil loss in tons per hectare. The combination of modified land use map and slope information helped to identify similar olive fields with high erosive potential. Results show that the method provides medium-term quantitative estimates for averaged soil loss consistent with some existing results from similar research areas in the Mediterranean. They clearly indicate the significant potential for erosion in olive orchards with around 95 ± 8 t ha- 1 yr- 1. Tillage practice and water erosion were identified as critical erosion processes, both depending on tillage characteristics, tillage timing, and soil parent material. The investigated fields represent about 19% of the catchment's surface area and are likely to contribute to the measured yearly sediment yield that fills up the Wadi Al-Arab reservoir with sediments.

  20. Effects of rock fragments on water dynamics in a fire-affected soil

    NASA Astrophysics Data System (ADS)

    Gordillo-Rivero, Ángel J.; García-Moreno, Jorge; Jordán, Antonio; Zavala, Lorena M.

    2014-05-01

    Rock fragments (RF) are common in the surface of Mediterranean semiarid soils, and have important effects on the soil physical (bulk density and porosity) and hydrological processes (infiltration, evaporation, splash erosion and runoff generation) (Poesen and Lavee, 1994; Rieke-Zapp et al., 2007). In some cases, RFs in Mediterranean areas have been shown to protect bare soils from erosion risk (Cerdà, 2001; Martínez-Zavala, Jordán, 2008; Zavala et al., 2010). Some of these effects are much more relevant when vegetation cover is low or has been reduced after land use change or other causes, as forest fires. Although very few studies exist, the interest on the hydrological effects of RFs in burned areas is increasing recently. After a forest fire, RFs may contribute significantly to soil recovery. In this research we have studied the effect of surface and embedded RFs on soil water control, infiltration and evaporation in calcareous fire-affected soils from a Mediterranean area (SW Spain). For this study, we selected an area with soils derived from limestone under holm oak forest, recently affected by a moderate severity forest fire. The proportion of RF cover showed a significant positive relation with soil water-holding capacity and infiltration rates, although infiltration rate reduced significantly when RF cover increased above a certain threshold. Soil evaporation rate decreased with increasing volumetric content of RFs and became stable with RF contents approximately above 30%. Evaporation also decreased with increasing RF cover. When RF cover increased above 50%, no significant differences were observed between burned and control vegetated plots. REFERENCES Poesen, J., Lavee, H. 1994. Rock fragments in top soils: significance and processes. Catena Supplement 23, 1-28. Cerdà, A. 2001. Effect of rock fragment cover on soil infiltration, interrill runoff and erosion. European Journal of Soil Science 52, 59-68. DOI: 10.1046/j.1365-2389.2001.00354.x. Rieke

  1. Unravelling the influence of soil erosion on the within-field vertical heterogeneity of SOC stock and stability

    NASA Astrophysics Data System (ADS)

    Meersmans, Jeroen; Quine, Tim; Hartley, Iain

    2014-05-01

    Intensified agro-management since the green revolution (from halfway the 20th century) significantly increased soil erosion and its associated lateral fluxes of soil properties within agricultural catchments. During this relatively short period of time considerably large amounts of fertile topsoil have been removed from erosional sites and have accumulated in depositional zones. As a consequence, the associated three dimensional spatial distribution of SOC has been modified significantly, especially within croplands under conventional tillage. As on the one hand erosion affects the stability of soil organic matter (i.e. breakdown of soil aggregates during transport process) and on the other hand organic carbon in depositional zones is assumed to be stored in stable environments, the increased within-field differences in SOC probably cause a major change in regional SOC dynamics. Nevertheless, the variability of SOC at smaller scales in complex terrain driven by soil erosion, such as stable subsoil carbon buried in depositional areas, is still rather understudied and is not (well) represented in current regional C estimates. In the present study we aim to unravel the variation in quantity and quality of SOC depth distributions along typical hillslope transects under cropland (Devon, UK) and to relate these to soil redistribution rates and variations in C input, i.e. below and above ground biomass productivity. The radionuclide isotope Caesium-137 (137Cs) was used as proxy for soil erosion. SOC stability has been studied in a depth specific context by running long-term incubation experiments. Moreover, the effect of potential increased C input has been tested by applying different rates of glucose additions on some of the incubated soil samples. The results show contrasting vertical patterns in SOC stock and stability depending on the rate and type of erosion. For example, sites characterized by deposition due to water erosion (i.e. footslope) have much higher SOC

  2. Soil water erosion on Mediterranean vineyards. A review based on published data

    NASA Astrophysics Data System (ADS)

    Prosdocimi, Massimo; Cerdà, Artemi; Tarolli, Paolo

    2015-04-01

    Soil water erosion on cultivated lands is a severe threat to soil resources in the world (Leh et al., 2013; Zhao et al., 2013). In particular, Mediterranean areas deserve a particular attention because of their edaphic, topographic and climatic conditions. Among the cultivated lands, concerns have arisen about vineyards because, aside representing one of the most important crop in terms of income and employment, they also have proven to be the form of agricultural land that causes one of the highest soil losses (Tropeano et al., 1984; Leonard and Andrieux, 1998; Ferrero et al., 2005; Cerdà et al., 2007; Blavet et al., 2009; Casalí et al., 2009; Novara et al., 2011; Martínez Casasnovas et al., 2013; Ruiz Colmenero et al., 2013; Tarolli et al., 2014). Although the topic of soil water erosion on vineyards has been studied, it still raises uncertainties. These are due to the i) high complexity of processes involved, ii) different methodologies used to analyze them and iii) analyses carried out at different spatial and temporal scales. At this regard, this work aims to evaluate the impact of factors controlling erosion such as rainfall characteristics, topography, soil properties and soil and water conservation techniques. Data derived from experimental plots have been reviewed. At first, what emerges is the difficulty of comparing erosion rates obtained with different methodologies and at different spatial scales. Secondly, all the factors demonstrate to have a strong impact on soil erosion but a 'general rule' upon which to consider one factor always predominant over the others does not come out. Therefore, this work supports the importance of monitoring soil water erosion by field measurements to better understand the relationship between the factors. Variables like rainfall characteristics, topography and soil properties are much more difficult to modify than the soil and water management techniques. Hence, future researches are needed to both recommend the best

  3. A 2500 year record of natural and anthropogenic soil erosion in South Greenland

    NASA Astrophysics Data System (ADS)

    Massa, Charly; Bichet, Vincent; Gauthier, Émilie; Perren, Bianca B.; Mathieu, Olivier; Petit, Christophe; Monna, Fabrice; Giraudeau, Jacques; Losno, Rémi; Richard, Hervé

    2012-01-01

    The environmental impact of the Norse landnám (colonization) in Greenland has been studied extensively. But to date, no study has quantified the soil erosion that Norse agricultural practices are believed to have caused. To resolve this problem, a high resolution sedimentary record from Lake Igaliku in South Greenland is used to quantitatively reconstruct 2500 years of soil erosion driven by climate and historical land use. An accurate chronology, established on 18 AMS 14C, and 210Pb and 137Cs dates, allows for the estimation of detritic fluxes and their uncertainties. Land clearance and the introduction of grazing livestock by the Norse around 1010 AD caused an acceleration of soil erosion up to ˜8 mm century -1 in 1180 AD which is two-fold higher than the natural pre- landnám background. From 1335 AD to the end of the Norse Eastern Settlement (in the mid-fifteenth century), the vegetation began to recover from initial disturbance and soil erosion decreased. After an initial phase of modern sheep breeding similar to the medieval one, the mechanization of agriculture in the 1980s caused an unprecedented soil erosion rate of up to ˜21 mm century -1, five times the pre-anthropogenic levels. Independently, a suite of biological and geochemical proxies (including Ti and diatom concentrations, C:N ratio, δ13C and δ15N of organic matter) confirm that the medieval and modern anthropogenic erosion far exceeds any natural erosion over the last 2500 years. Our findings question the veracity of the catastrophic scenario of overgrazing and land degradation considered to have been the major factor responsible for Norse settlement demise. They also shed light on the sustainability of modern practices and their consequences for the future of agriculture in Greenland.

  4. Research on the relationship between soil erosion and landscape pattern in the Wuyuer River basin based on GIS

    NASA Astrophysics Data System (ADS)

    Wang, Wenjuan; Zhang, Shuwen; Li, Ying; Deng, Rongxin; Yan, Yechao

    2009-07-01

    In recent years, soil erosion has been an increasing concern in the Black Soil Area of Northeast China because of its harm to the marketable grain basis in China. Taken Wuyuer river basin in Black Soil Area of Northeast China as study area, Using GIS, RS and USLE, by choosing the reasonable calculating methods to get each factor in the USLE, we evaluated the soil erosion of this basin in 2005a. Otherwise, chosen the 48 subbasin as basic analysis units, with the spatial analysis ability of GIS and FRAGSTAT software, it get the soil erosion modulus and corresponding landscape pattern metrics in each subbasin. Base on these data, the relationship between soil erosion and landscape pattern was analyzed and the result can provide suggestion for landuse planning and soil erosion control. It shows that middle and upper reaches of Wuyuer river basin is the main erosion region, and its mean soil erosion modulus is 258.85t/(km2•a), which is higher than the tolerable soil loss rate in Black Soil Area of Northeast China. This region needs erosion control urgently. Correlation analysis shows a positive correlation between percentage of landscape(PLAND) of cropland, grassland, Perimeter-Area Fractal Dimension (PAFRAC), Shannon's Diversity Index (SHDI) and soil erosion modulus; Percentage of landscape(PLAND)of forest land as well as Contagion Index(CONTAG) show negative correlation with erosion modulus. With further analysis, it concludes that regulating the landscape pattern in cropland, grassland and forestland reasonably is very important for the soil erosion control and management.

  5. Assessment of Soil Moisture and Fixatives Performance in Controlling Wind Erosion of Contaminated Soil at the Hanford Site

    SciTech Connect

    Lagos, L.E.; Gudavalli, R.K.

    2008-07-01

    During the remediation of burial grounds at the US Department of Energy's (DOE's) Hanford Site in Washington State, the dispersion of contaminated soil particles and dust is an issue that is faced by site workers on a daily basis. This contamination issue is even more of a concern when one takes into account the semi-arid characteristics of the region where the site is located. To mitigate this problem, workers at the site use a variety of engineered methods to minimize the dispersion of contaminated soil and dust particles. Once such methods is the use of water and/or suppression agents (fixatives) that stabilizes the soil prior to soil excavation, segregation, and removal activities. A primary contributor to the dispersion of contaminated soil and dust is wind soil erosion. The erosion process occurs when the wind speed exceeds a certain threshold value (threshold shear velocity), which depends on a number of factors including wind force loading, particle size, surface soil moisture, and the geometry of the soil. Thus under these circumstances the mobility of contaminated soil and generation and dispersion of particulate matter are significantly influenced by these parameters. Wind tunnel experiments were conducted at the Florida International University's Applied Research Center (FIU-ARC) to evaluate the effectiveness of three commercially available fixatives in controlling the mobility of soil particles on soil mounds when exposed to varying wind forces. The fixatives tested included: (1) a calcium chloride solution; (2) a petroleum hydrocarbon emulsion; and 3) a synthetic organic. As an initial step, approximately 500 lbs of uncontaminated soil was obtained from the Hanford Reservation in Washington State. Soil samples were placed in an open-loop, low speed wind tunnel and exposed to wind forces ranging from 10 to 30 miles per hour (mph). Wind erosion controlling capabilities of commercially available fixatives and soil moisture were tested at a laboratory

  6. Estimation of Soil Erosion Rates in Oil Palm Plantation with Different Land Cover

    NASA Astrophysics Data System (ADS)

    Sahat, S.; Yusop, Z.; Askari, M.; Ziegler, A. D.

    2016-07-01

    Soil losses from hill slopes in oil palm plantation in Sedenak Estate, Johor were measured using runoff plot and rainfall simulator. The plot was designed to be removable but the size was fixed at 8 x 3.75m. Four types of surface covers were investigated for the plots, i.e. half bare soil and half grass cover (HGC), half bare soil and half dry frond (HDF), fully grass cover (FG), and fully bare soil (BS). The influence of initial soil moisture, saturated hydraulics conductivity, Ks, bulk density and slope on rates of soil loss were also evaluated. The rainfall simulator produced rainfall intensities between 90 and 160 mm/hr with durations from 45 to 60 min per run. BS plot exhibited the highest Ks value among all plots but the percentage of initial soil moisture on this surface was low. BS plot recorded the highest runoff coefficient (C) and soil loss values of 73.6 ± 4 percent and 5.26 ± 3.2 t/ha respectively, while the lowest was from plot FG with 41.7 ± 5.7 percent and soil loss of 2.85 ± 2.1 t/ha. Meanwhile, the results suggested that the ground cover had the ability to reduce soil loss by 67% and 17%, respectively for plots BS-HGC and BS-HDF. Overall, soil erosion control such as surface is effective measures in reducing level of runoff and soil erosion.

  7. Large-scale assessment of soil erosion in Africa: satellites help to jointly account for dynamic rainfall and vegetation cover

    NASA Astrophysics Data System (ADS)

    Vrieling, Anton; Hoedjes, Joost C. B.; van der Velde, Marijn

    2015-04-01

    Efforts to map and monitor soil erosion need to account for the erratic nature of the soil erosion process. Soil erosion by water occurs on sloped terrain when erosive rainfall and consequent surface runoff impact soils that are not well-protected by vegetation or other soil protective measures. Both rainfall erosivity and vegetation cover are highly variable through space and time. Due to data paucity and the relative ease of spatially overlaying geographical data layers into existing models like USLE (Universal Soil Loss Equation), many studies and mapping efforts merely use average annual values for erosivity and vegetation cover as input. We first show that rainfall erosivity can be estimated from satellite precipitation data. We obtained average annual erosivity estimates from 15 yr of 3-hourly TRMM Multi-satellite Precipitation Analysis (TMPA) data (1998-2012) using intensity-erosivity relationships. Our estimates showed a positive correlation (r = 0.84) with long-term annual erosivity values of 37 stations obtained from literature. Using these TMPA erosivity retrievals, we demonstrate the large interannual variability, with maximum annual erosivity often exceeding two to three times the mean value, especially in semi-arid areas. We then calculate erosivity at a 10-daily time-step and combine this with vegetation cover development for selected locations in Africa using NDVI - normalized difference vegetation index - time series from SPOT VEGETATION. Although we do not integrate the data at this point, the joint analysis of both variables stresses the need for joint accounting for erosivity and vegetation cover for large-scale erosion assessment and monitoring.

  8. Modeling of Soil Erosion by IntErO model: The Case Study of the Novsicki Potok Watershed, of the Prokletije high mountains of Montenegro

    NASA Astrophysics Data System (ADS)

    Spalevic, Velibor; Al-Turki, Ali M.; Barovic, Goran; Leandro Naves Silva, Marx; Djurovic, Nevenka; Soares Souza, Walisson; Veloso Gomes Batista, Pedro; Curovic, Milic

    2016-04-01

    novel concept and is highly recommended for soil erosion modelling in other river basins similar to the studied watershed, because of its simple identification of critical areas affected by the soil loss caused by soil erosion.

  9. Land rehabilitation, erosion and C sequestration in soils of the Chinese Loess Plateau

    NASA Astrophysics Data System (ADS)

    Li, Yong; Van Oost, Kristof; Quine, Tim; Govers, Gerard

    2013-04-01

    Once the cradle of Chinese civilization, the Chinese loess plateau is now one of the most degraded ecosystems in the world and a wide range of ecological rehabilitation programs have been implemented since the 1950s that aim at facilitating synergies between soil conservation, food production and socio-economic welfare. More recently, the scope of vegetation restoration programs has been extended to include sequestration of C by soils and the reconversion of 4.8 million ha of cropland to forest and grassland has re-sequestered a substantial amount of C in soils between 2000 and 2008. Although this appears to represent a significant win-win, these estimates are associated with considerable uncertainty both due to the extrapolation and, significantly, because of the assumptions made about the pre-restoration state. Here, we argue that a full assessment of the C sequestration benefit of land rehabilitation programs requires quantification not only of the C uptake in vegetation and plants under the new land use regime (as has been undertaken), but also of the soil atmosphere C exchange associated with the elevated erosion rates that typify the pre-restoration state. We present the results of an intensive measurement campaign to characterize the erosional control on vertical carbon fluxes from degraded land, typical of the pre-restoration state. We report year-round soil respiration (in the absence of vegetation) measurements with high temporal resolution along an erosion gradient on cultivated sloping land in the Chinese Loess Plateau. At 14 sites along an eroding cultivated slope, we quantified the temporal dynamics of soil CO2 fluxes using an Automated Soil CO2 Flux System. This resulted in 13296 respiration measurements between April 2007 and September 2008. We investigate the factors controlling in-situ soil respiration, including soil temperature, moisture, soil erosion and SOC stock and quality. Soil and, by inference, C erosion and deposition since 1954 were

  10. Critical shear stress for erosion of cohesive soils subjected to temperatures typical of wildfires

    USGS Publications Warehouse

    Moody, J.A.; Dungan, Smith J.; Ragan, B.W.

    2005-01-01

    [1] Increased erosion is a well-known response after wildfire. To predict and to model erosion on a landscape scale requires knowledge of the critical shear stress for the initiation of motion of soil particles. As this soil property is temperature-dependent, a quantitative relation between critical shear stress and the temperatures to which the soils have been subjected during a wildfire is required. In this study the critical shear stress was measured in a recirculating flume using samples of forest soil exposed to different temperatures (40??-550??C) for 1 hour. Results were obtained for four replicates of soils derived from three different types of parent material (granitic bedrock, sandstone, and volcanic tuffs). In general, the relation between critical shear stress and temperature can be separated into three different temperature ranges (275??C), which are similar to those for water repellency and temperature. The critical shear stress was most variable (1.0-2.0 N m-2) for temperatures 2.0 N m-2) between 175?? and 275??C, and was essentially constant (0.5-0.8 N m-2) for temperatures >275??C. The changes in critical shear stress with temperature were found to be essentially independent of soil type and suggest that erosion processes in burned watersheds can be modeled more simply than erosion processes in unburned watersheds. Wildfire reduces the spatial variability of soil erodibility associated with unburned watersheds by eliminating the complex effects of vegetation in protecting soils and by reducing the range of cohesion associated with different types of unburned soils. Our results indicate that modeling the erosional response after a wildfire depends primarily on determining the spatial distribution of the maximum soil temperatures that were reached during the wildfire. Copyright 2005 by the American Geophysical Union.

  11. Discriminating impacts of geomorphological and human factors on vineyard soil erosion (Burgundy, France)

    NASA Astrophysics Data System (ADS)

    Chevigny, Emmanuel; Quiquerez, Amélie; Petit, Christophe; Curmi, Pierre

    2014-05-01

    The Burgundy vineyards have been recognized for the high diversity of Terroirs, controlled by complex interactions between natural features, historical parameters and soil management practices. Vineyards are known to undergo substantial soil loss in comparison with other types of agricultural land. Hydric erosion on vineyards is controlled by complex interactions of natural and anthropogenic factors leading to intra-plot spatial heterogeneities of topsoil at a scale of a metre. Studying the relationship between soils and their degradation is crucial in this situation where soil sustainability is threatened. This study explores the relative influences of historical and present-day anthropogenic factors and geomorphological processes controlling soil erosion on vineyard hillslopes. The selected area was located in the Monthelie vineyard (Côte de Beaune, France) where intensive erosion occurred during high-intensity rainfall events. Soil erosion quantification was performed at a square-metre scale using dendrogeomorphology. This method is based on the measurement of the unearthing of the stock located on the vine plants, considered as a passive marker of soil-surface vertical displacement since the year of plantation. The obtained maps, together with various complementary datasets, such as geological and geomorphological data, but also historical documents (cadastral plans, cadastral matrices and old aerial photographs) allow landscape evolution to be assessed. The combination of all these data shows that spatial distribution and intensity of erosion are controlled mainly by lithology and slope value. However, our study highlights that the sediment dynamics in this vineyard plot is highly related to historical former plot limits and present-day management practices. Nonetheless, quantification of sediment dynamic for the last decade reveals that the impacts of historical structures are disappearing gradually, in response to present-day management practices and

  12. Approaches for delineating landslide hazard areas using receiver operating characteristic in an advanced calibrating precision soil erosion model

    NASA Astrophysics Data System (ADS)

    Ghazvinei, P. T.; Zandi, J.; Ariffin, J.; Hashim, R. B.; Motamedi, S.; Aghamohammadi, N.; Moghaddam, D. A.

    2015-10-01

    Soil erosion is undesirable natural event that causes land degradation and desertification. Identify the erosion-prone areas is a major component of preventive measures. Recent landslide damages at different regions lead us to develop a model of the erosion susceptibility map using empirical method (RUSLE). A landslide-location map was established by interpreting satellite image. Field observation data was used to validate the intensity of soil erosion. Further, a correlation analysis was conducted to investigate the "Receiver Operating Characteristic" and frequency ratio. Results showed a satisfactory correlation between the prepared RUSLE-based soil erosion map and actual landslide distribution. The proposed model can effectively predict the landslide events in soil-erosion area. Such a reliable predictive model is an effective management facility for the regional landslide forecasting system.

  13. Physical and analytical modeling of upland soil erosion due to headcut migration

    NASA Astrophysics Data System (ADS)

    Bennett, S. J.; Alonso, C. V.

    2002-12-01

    On hillslopes and agricultural fields, discrete areas of intense, localized soil erosion commonly take place in the form of migrating headcuts. These erosional features significantly increase soil loss and landscape degradation, yet the unsteady, transient, and migratory habits of headcuts complicate their phenomenological and erosional characterization. Here a unique experimental facility was constructed to examine actively migrating headcuts typical of upland concentrated flows. Essential components of the facility include a deep soil cavity with external drainage, rainfall simulator, overland flow, and a video recording technique for data collection. These experiments provided unrivalled insight into steady state soil erosion processes, self-similarity of migrating headcuts, and integral time and length scales for headcut development. Several examples of migrating headcuts and their salient characteristics will be shown using the video recordings, including the effects of flow rate, bed slope, and initial step height on headcut dimensions, turbulent flow structure within the scour hole, and the distribution of bed pressure along the headcut face. It will be shown that erosion processes are controlled by the characteristics of the overfall nappe and wall jets within the plunge pool and that modified jet impingement theory can be successfully applied to a migrating headcut. These experiments provided the insight as well as the conceptual framework for a complete analytical solution for predicting headcut migration rate, equilibrium scour depth, and total sediment flux in upland concentrated flows. Without such experiments, the formative processes of headcut erosion in soils would remain speculative at best.

  14. Soil tillage conservation and its effect on erosion control, water management and carbon sequestration

    NASA Astrophysics Data System (ADS)

    Rusu, Dr.; Gus, Dr.; Bogdan, Dr.; Moraru, Dr.; Pop, Dr.; Clapa, Dr.; Pop, Drd.

    2009-04-01

    The energetic function of the soil expressed through the potential energy accumulated through humus, the biogeochemical function (the circuit of the nutrient elements) are significantly influenced by its hydrophysical function and especially by the state of the bedding- consolidation, soil capacity of retaining an optimal quantity of water, and then its gradual disponibility for plant consumption. The understanding of soil functions and management including nutrient production, stocking, filtering and transforming minerals, water , organic matter , gas circuit and furnishing breeding material, all make the basis of human activity, Earth's past, present and especially future. The minimum tillage soil systems - paraplow, chisel or rotary grape - are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for: soil natural fertility activation and rationalization, reduction of erosion, increasing the accumulation capacity for water and realization of sowing in the optimal period. By continuously applying for 10 years the minimum tillage system in a crop rotation: corn - soy-bean - wheat - potato / rape, an improvement in physical, hydro-physical and biological properties of soil was observed, together with the rebuilt of structure and increase of water permeability of soil. The minimum tillage systems ensure an adequate aerial-hydrical regime for the biological activity intensity and for the nutrients solubility equilibrium. The vegetal material remaining at the soil surface or superficially incorporated has its contribution to intensifying the biological activity, being an important resource of organic matter. The minimum tillage systems rebuild the soil structure, improving the global drainage of soil which allows a rapid infiltration of water in soil. The result is a more productive soil, better protected against wind and water erosion and needing less

  15. Soil tillage conservation and its effect on erosion control, water management and carbon sequestration

    NASA Astrophysics Data System (ADS)

    Rusu, T.; Gus, P.; Bogdan, I.; Moraru, P.; Pop, A.; Clapa, D.; Pop, L.

    2009-04-01

    The energetic function of the soil expressed through the potential energy accumulated through humus, the biogeochemical function (the circuit of the nutrient elements) are significantly influenced by its hydrophysical function and especially by the state of the bedding- consolidation, soil capacity of retaining an optimal quantity of water, and then its gradual disponibility for plant consumption. The understanding of soil functions and management including nutrient production, stocking, filtering and transforming minerals, water , organic matter, gas circuit and furnishing breeding material, all make the basis of human activity, Earth's past, present and especially future. The minimum tillage soil systems - paraplow, chisel or rotary grape - are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for: soil natural fertility activation and rationalization, reduction of erosion, increasing the accumulation capacity for water and realization of sowing in the optimal period. By continuously applying for 10 years the minimum tillage system in a crop rotation: corn - soy-bean - wheat - potato / rape, an improvement in physical, hydro-physical and biological properties of soil was observed, together with the rebuilt of structure and increase of water permeability of soil. The minimum tillage systems ensure an adequate aerial-hydrical regime for the biological activity intensity and for the nutrients solubility equilibrium. The vegetal material remaining at the soil surface or superficially incorporated has its contribution to intensifying the biological activity, being an important resource of organic matter. The minimum tillage systems rebuild the soil structure, improving the global drainage of soil which allows a rapid infiltration of water in soil. The result is a more productive soil, better protected against wind and water erosion and needing less

  16. Testing for supply-limited chemical erosion in field measurements of soil production and chemical depletion

    NASA Astrophysics Data System (ADS)

    Ferrier, K.; Riebe, C. S.; Hahm, W. J.; Kirchner, J. W.

    2014-12-01

    Quantifying the controls on chemical erosion rates in eroding landscapes is of wide interest because chemical erosion influences nutrient supply, landscape evolution, soil production, and Earth's long-term climate. Several field studies have suggested that chemical erosion rates increase in proportion to the rates that minerals are supplied to the regolith, a condition known as supply-limited chemical erosion. This condition, if broadly applicable, implies strong tectonic control of silicate weathering rates and hence Earth's long-term climate. While it is plausible that chemical erosion rates should scale with supply rates, attempts to test whether chemical erosion rates are in fact supply-limited at any given site are hampered by several difficulties. For instance, the quantities that are most frequently used to test for supply limitation (i.e., rates of chemical erosion and denudation in regolith-based studies, and fluxes of sediment and solutes in river-based studies) are artifactually correlated, which complicates attempts to regress one variable against another. Here we present a statistical method for testing for supply-limited chemical erosion, and we apply this method to a number of published datasets. Our results suggest that many datasets are inadequate for determining whether chemical erosion in regolith is or is not supply-limited, largely because the uncertainties on the regression parameters are large. This in turn suggests that new measurements across a wide range of supply rates are needed to determine the strength of tectonic controls on chemical erosion, and, ultimately, to test hypotheses about feedbacks between surface processes, silicate weathering, and the long-term evolution of Earth's climate.

  17. Minimally invasive prosthetic procedures in the rehabilitation of a bulimic patient affected by dental erosion

    PubMed Central

    Derchi, Giacomo; Peñarrocha, David; Barone, Antonio; Covani, Ugo

    2015-01-01

    The population affected by dental erosion due to bulimia is generally very young. This population group has a high aesthetic requirement; the dentition in these patients is severely damaged, especially in the anterior maxillary quadrant. In terms of treatment, it is still controversial whether an adhesive rehabilitation is preferable to a longer-lasting but more aggressive conventional treatment, such as full-crown coverage of the majority of teeth. This case report describes the prosthetic rehabilitation of a young female patient previously affected by bulimia nervosa and presenting erosion of the maxillary teeth. The prosthetic rehabilitation was performed through indirect adhesive restorations of the anterior teeth and direct restorations of the posterior teeth. A clinical follow-up after 4 years showed that the occlusion remained satisfactorily restored. Posterior direct composite resin restorations and anterior indirect adhesive composite restorations proved to be an effective time and money-saving procedure to rehabilitate patients affected by dental erosion. Adhesive rehabilitation provides a functional and good aesthetic result while preserving tooth structure. Key words:Bulimia, dental erosion, composite resin, veneers. PMID:25810832

  18. Transport mechanisms of soil-bound mercury in the erosion process during rainfall-runoff events.

    PubMed

    Zheng, Yi; Luo, Xiaolin; Zhang, Wei; Wu, Xin; Zhang, Juan; Han, Feng

    2016-08-01

    Soil contamination by mercury (Hg) is a global environmental issue. In watersheds with a significant soil Hg storage, soil erosion during rainfall-runoff events can result in nonpoint source (NPS) Hg pollution and therefore, can extend its environmental risk from soils to aquatic ecosystems. Nonetheless, transport mechanisms of soil-bound Hg in the erosion process have not been explored directly, and how different fractions of soil organic matter (SOM) impact transport is not fully understood. This study investigated transport mechanisms based on rainfall-runoff simulation experiments. The experiments simulated high-intensity and long-duration rainfall conditions, which can produce significant soil erosion and NPS pollution. The enrichment ratio (ER) of total mercury (THg) was the key variable in exploring the mechanisms. The main study findings include the following: First, the ER-sediment flux relationship for Hg depends on soil composition, and no uniform ER-sediment flux function exists for different soils. Second, depending on soil composition, significantly more Hg could be released from a less polluted soil in the early stage of large rainfall events. Third, the heavy fraction of SOM (i.e., the remnant organic matter coating on mineral particles) has a dominant influence on the enrichment behavior and transport mechanisms of Hg, while clay mineral content exhibits a significant, but indirect, influence. The study results imply that it is critical to quantify the SOM composition in addition to total organic carbon (TOC) for different soils in the watershed to adequately model the NPS pollution of Hg and spatially prioritize management actions in a heterogeneous watershed. PMID:27176760

  19. Detecting soil erosion in semi-arid mediterranean environments using simulated EnMAP data

    NASA Astrophysics Data System (ADS)

    Bracken, Ashley H.

    Soil is an essential nature resource. Management of this resource is vital for sustainability and the continued functioning of earths atmospheric, hydrospheric and lithospheric functioning. The assessment and continued monitoring of surface soil state provides the information required to effectively manage this resource. This research used a simulated Environmental Mapping and Analysis Program (EnMAP) hyperspectral image cube of an agricultural region in semi- arid Mediterranean Spain to classify soil erosion states. Multiple Endmember Spectral Mixture Analysis (MESMA) was used to derive within pixel fractions of eroded and accumulated soils. A Classification of the soil erosion states using the scene fraction outputs and digital terrain information. The information products generated in this research provided an optimistic outlook for the applicability of the future EnMAP sensor for soil erosion investigations in semi-arid Mediterranean environments. Additionally, this research verifies that the launch of the EnMAP satellite sensor in 2018 will provide t