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Sample records for agricultural soil erosion

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. Can biosolids reduce wind erosion of agricultural soils?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The application of biosolids to agricultural land has the potential to improve soil health and crop production. In addition, organic material contained in biosolids may enhance biological activity, retention of soil water, and soil aggregation. Thus, there is a likelihood that biosolids applied to s...

  10. 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).

  11. 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.

  12. 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.

  13. 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.

  14. Utilizing of magnetic parameters for evaluation of soil erosion rates on two different agricultural sites

    NASA Astrophysics Data System (ADS)

    Kapicka, A.; Grison, H.; Petrovsky, E.; Jaksik, O.; Kodesova, R.

    2015-12-01

    Field measurements of magnetic susceptibility were carried out on regular grid, resulting in 101 data points at Brumovice and 65 at Vidim locality. Mass specific magnetic susceptibility χ and its frequency dependence χFD was used to estimate the significance of SP ferrimagnetic particles of pedogenic origin in topsoil horizons. The lowest magnetic susceptibility was obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). Soil profiles unaffected by erosion were investigated in detail. The vertical distribution of magnetic susceptibility along these "virgin" profiles was measured in laboratory on samples collected with 2-cm spacing. The differences between the distribution of susceptibility in the undisturbed soil profiles and the magnetic signal after uniform mixing of the soil material as a result of erosion and tillage are fundamental for the estimation of soil loss in the studied test fields. Maximum cumulative soil erosion depth in Brumovice and Vidim is around 100 cm and 50 cm respectively. The magnetic method is suitable for mapping at the chernozem localities and measurement of soil magnetic susceptibility is in this case useful and fast technique for quantitative estimation of soil loss caused by erosion. However, it is less suitable (due to lower magnetic differentiation with depth) in areas with luvisol as dominant soil unit. Acknowledgement: This study was supported by NAZV Agency of the Ministry of Agriculture of the Czech Republic through grant No QJ1230319.

  15. 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.

  16. 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

  17. Use of Magnetic Parameters to Asses Soil Erosion Rates on Agricultural Site

    NASA Astrophysics Data System (ADS)

    Petrovsky, E.; Kapicka, A.; Dlouha, S.; Jaksik, O.; Grison, H.; Kodesova, R.

    2014-12-01

    A detailed field study on a small test site of agricultural land situated in loess region in Southern Moravia (Czech Republic) and laboratory analyses were carried out in order to test the applicability of magnetic methods in assessing soil erosion. Haplic Chernozem, the original dominant soil unit in the area, is nowadays progressively transformed into different soil units along with intense soil erosion. As a result, an extremely diversified soil cover structure has developed due to the erosion. The site was characterized by a flat upper part while the middle part, formed by a substantive side valley, is steeper. We carried out field measurements of magnetic susceptibility on a regular grid, resulting in 101 data points. The bulk soil material for laboratory investigation was gathered from all the grid points. Values of the magnetic susceptibility are spatially distributed depending on the terrain. Higher values were measured in the flat upper part (where the original top horizon remained). The lowest values of were obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). A soil profile unaffected by erosion was investigated in detail. The vertical distribution of magnetic susceptibility along this "virgin" profile was measured in laboratory on the samples collected with 2-cm spacing. The undisturbed profile shows several soil horizons. Horizons Ac and A show a slight increase in magnetic susceptibility up to a depth of about 70 cm. Horizon A/Ck is characterized by a decrease in susceptibility, and the underlying C horizon (h > 103 cm) has a very low value of magnetic susceptibility. The differences between the values of susceptibility in the undisturbed soil profile and the magnetic signal after uniform mixing the soil material as a result of tillage and erosion are fundamental for the estimation of soil loss in the studied test field. Using the uneroded profile from the studied locality as a

  18. Effectiveness of conservation agriculture practices on soil erosion processes in semi-arid areas of Zimbabwe

    NASA Astrophysics Data System (ADS)

    Chikwari, Emmanuel; Mhaka, Luke; Gwandu, Tariro; Chipangura, Tafadzwa; Misi Manyanga, Amos; Sabastian Matsenyengwa, Nyasha; Rabesiranana, Naivo; Mabit, Lionel

    2016-04-01

    - The application of fallout radionuclides (FRNs) in soil erosion and redistribution studies has gained popularity since the late 1980s. In Zimbabwe, soil erosion research was mostly based on conventional methods which included the use of erosion plots for quantitative measurements and erosion models for predicting soil losses. Only limited investigation to explore the possibility of using Caesium-137 (Cs-137) has been reported in the early 1990s for undisturbed and cultivated lands in Zimbabwe. In this study, the Cs-137 technique was applied to assess the impact of soil conservation practices on soil losses and to develop strategies and support effective policies that help farmers in Zimbabwe for sustainable land management. The study was carried out at the Makoholi research station 30 km north of the Masvingo region which is located 260 km south of Harare. The area is semi-arid and the study site comprises coarse loamy sands, gleyic lixisols. The conservation agriculture (CA) practices used within the area since 1988 include (i) direct seeding (DS) with mulch, (ii) CA basins with mulch, and (iii) 18 years direct seeding, left fallow for seven years and turned into conventional tillage since 2012 (DS/F/C). The Cs-137 reference inventory was established at 214 ± 16 Bq/m2. The mean inventories for DS, CA basins and DS/F/C were 195, 190 and 214 Bq/m2 respectively. Using the conversion Mass Balance Model 2 on the Cs-137 data obtained along transects for each of the practices, gross erosion rates were found to be 7.5, 7.3 and 2.6 t/ha/yr for direct seeding, CA basins and the DS/F/C while the net erosion rates were found to be 3.8, 4.6 and 0 t/ha/yr respectively. Sediment delivery ratios were 50%, 63% and 2% in the respective order. These preliminary results showed the effectiveness of DS over CA basins in erosion control. The efficiency of fallowing in controlling excessive soil loss was significant in the plot that started as DS for 18 years but left fallow for 7

  19. Weathering and erosion of soils in the agricultural Middle Hills of Nepal

    NASA Astrophysics Data System (ADS)

    West, A. Joshua

    2015-04-01

    The role of land use in changing the pace of mineral weathering and associated soil formation processes has been widely documented, but many questions remain to be fully addressed. The flux of dissolved constituents in streams and rivers, often used to infer weathering rates, is in many cases enhanced from agricultural lands. Observed increases may be related to a variety of factors including changes in hydrology and the use of chemical fertilizers, as well as practices such as tilling. This study focuses on a site in the Middle Hills of the Nepal Himalaya where previous research has indicated differences in stream chemistry attributable to land use. The work presented here explores the application of both Be-10 and U-series isotopic systems in assessing the role of agricultural activities in soil erosion. This study also considers soil chemistry and mineralogy under both pristine and agricultural land use and shows in particular that there are distinct differences in the distribution of weatherable minerals in soils from agricultural terraces, potentially contributing to differences in overall weathering in these soils.

  20. Glyphosate and AMPA contents in sediments produced by wind erosion of agricultural soils in Argentina

    NASA Astrophysics Data System (ADS)

    Aparicio, Virginia; Aimar, Silvia; De Gerónimo, Eduardo; Buschiazzo, Daniel; Mendez, Mariano; Costa, José Luis

    2014-05-01

    Wind erosion of soils is an important event in arid and semiarid regions of Argentina. The magnitude of wind erosion occurring under different management practices is relatively well known in this region but less information is available on the quality of the eroded material. Considering that the intensification of agriculture may increase the concentrations of substances in the eroded material, producing potential negative effects on the environment, we analyzed the amount of glyphosate and AMPA in sediments produced by wind erosion of agricultural soils of Argentina. Wind eroded materials were collected by means of BSNE samplers in two loess sites of the semiarid region of Argentina: Chaco and La Pampa. Samples were collected from 1 ha square fields at 13.5, 50 and 150 cm height. Results showed that at higher heights the concentrations of glyphosate and AMPA were mostly higher. The glyphosate concentration was more variable and higher in Chaco (0.66 to 313 µg kg-1) than in La Pampa (4.17 to 114 µg kg-1). These results may be due to the higher use of herbicides in Chaco, where the predominant crops are soybeans and corn, produced under no-tillage. Under these conditions the use of glyphosate for weeds control is a common practice. Conversely, AMPA concentrations were higher in La Pampa (13.1 to 101.3 µg kg-1) than in Chaco (1.3 to 83 µg kg-1). These preliminary results show high concentrations of glyphosate and AMPA in wind eroded materials of agricultural soils of Argentina. More research is needed to confirm these high concentrations in other conditions in order to detect the temporal and spatial distribution patterns of the herbicide.

  1. Estimation of soil erosion risk within an important agricultural sub-watershed in Bursa, Turkey, in relation to rapid urbanization.

    PubMed

    Ozsoy, Gokhan; Aksoy, Ertugrul

    2015-07-01

    This paper integrates the Revised Universal Soil Loss Equation (RUSLE) with a GIS model to investigate the spatial distribution of annual soil loss and identify areas of soil erosion risk in the Uluabat sub-watershed, an important agricultural site in Bursa Province, Turkey. The total soil loss from water erosion was 473,274 Mg year(-1). Accordingly, 60.3% of the surveyed area was classified into a very low erosion risk class while 25.7% was found to be in high and severe erosion risk classes. Soil loss had a close relationship with land use and topography. The most severe erosion risk typically occurs on ridges and steep slopes where agriculture, degraded forest, and shrubs are the main land uses and cover types. Another goal of this study was to use GIS to reveal the multi-year urbanization status caused by rapid urbanization that constitutes another soil erosion risk in this area. Urbanization has increased by 57.7% and the most areal change was determined in class I lands at a rate of 80% over 25 years. Urbanization was identified as one of the causes of excessive soil loss in the study area. PMID:26059559

  2. Estimation of soil erosion risk within an important agricultural sub-watershed in Bursa, Turkey, in relation to rapid urbanization.

    PubMed

    Ozsoy, Gokhan; Aksoy, Ertugrul

    2015-07-01

    This paper integrates the Revised Universal Soil Loss Equation (RUSLE) with a GIS model to investigate the spatial distribution of annual soil loss and identify areas of soil erosion risk in the Uluabat sub-watershed, an important agricultural site in Bursa Province, Turkey. The total soil loss from water erosion was 473,274 Mg year(-1). Accordingly, 60.3% of the surveyed area was classified into a very low erosion risk class while 25.7% was found to be in high and severe erosion risk classes. Soil loss had a close relationship with land use and topography. The most severe erosion risk typically occurs on ridges and steep slopes where agriculture, degraded forest, and shrubs are the main land uses and cover types. Another goal of this study was to use GIS to reveal the multi-year urbanization status caused by rapid urbanization that constitutes another soil erosion risk in this area. Urbanization has increased by 57.7% and the most areal change was determined in class I lands at a rate of 80% over 25 years. Urbanization was identified as one of the causes of excessive soil loss in the study area.

  3. Effect of land use land cover change on soil erosion potential in an agricultural watershed.

    PubMed

    Sharma, Arabinda; Tiwari, Kamlesh N; Bhadoria, P B S

    2011-02-01

    Universal soil loss equation (USLE) was used in conjunction with a geographic information system to determine the influence of land use and land cover change (LUCC) on soil erosion potential of a reservoir catchment during the period 1989 to 2004. Results showed that the mean soil erosion potential of the watershed was increased slightly from 12.11 t ha(-1) year(-1) in the year 1989 to 13.21 t ha(-1) year(-1) in the year 2004. Spatial analysis revealed that the disappearance of forest patches from relatively flat areas, increased in wasteland in steep slope, and intensification of cultivation practice in relatively more erosion-prone soil were the main factors contributing toward the increased soil erosion potential of the watershed during the study period. Results indicated that transition of other land use land cover (LUC) categories to cropland was the most detrimental to watershed in terms of soil loss while forest acted as the most effective barrier to soil loss. A p value of 0.5503 obtained for two-tailed paired t test between the mean erosion potential of microwatersheds in 1989 and 2004 also indicated towards a moderate change in soil erosion potential of the watershed over the studied period. This study revealed that the spatial location of LUC parcels with respect to terrain and associated soil properties should be an important consideration in soil erosion assessment process.

  4. 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

  5. Magnetism of soils applied for estimation of erosion at an agricultural land

    NASA Astrophysics Data System (ADS)

    Kapicka, Ales; Dlouha, Sarka; Grison, Hana; Jaksik, Ondrej; Kodesova, Radka; Petrovsky, Eduard

    2013-04-01

    A detailed field study on small test site of agricultural land situated in loess region in Southern Moravia (Czech Republic), followed by laboratory analyses, has been carried out in order to test the applicability of magnetic methods in soil erosion estimation. The approach is based on the well-established differentiation in magnetic signature of topsoil from subsoil horizons as a result of "in situ" formation of strongly magnetic iron oxides e.g. (Maher 1986). Introducing a simple tillage homogenization model for predicting magnetic signal after uniform mixing of soil material as a result of tillage and subsequent erosion, Royall (2001) showed that magnetic susceptibility and its frequency dependence can be used to estimate soil loss. Haplic Chernozem is an original dominant soil unit in the wider area, nowadays progressively transformed into different soil units along with intensive soil erosion. The site was characterized by a flat upper part while the middle part, formed by a substantive side valley, is steeper (up to 15°). The side valley represented a major line of concentrated runoff emptying into a colluvial fan (Zadorova et al., 2011; Jaksik et al., 2011). Field measurements of magnetic susceptibility were carried out on regular grid, resulting in 101 data points. Bulk soil material for laboratory investigation was gathered from all grid points. Mass specific magnetic susceptibility χ and its frequency dependence kFD was used to estimate the significance of SP ferrimagnetic particles of pedogenic origin. Thermomagnetic analyses, hysteresis measurement and SEM were used in order to determine dominant ferrimagnetic carriers in top-soil and sub-soil layers. Strong correlation was found between the volume magnetic susceptibility (field measurement) and mass specific magnetic susceptibility measured in the laboratory (R2 = 0.80). At the same time, no correlations were found between the values of kFD and mass specific susceptibility. Values of organic carbon

  6. Use of (137)Cs technique for soil erosion study in the agricultural region of Casablanca in Morocco.

    PubMed

    Nouira, A; Sayouty, E H; Benmansour, M

    2003-01-01

    Accelerated erosion and soil degradation currently cause serious problems to the Oued El Maleh basin (Morocco). Furthermore, there is still only limited information on rates of soil loss for optimising strategies for soil conservation. In the present study we have used the (137)Cs technique to assess the soil erosion rates on an agricultural land in Oued el Maleh basin near Casablanca (Morocco). A small representative agricultural field was selected to investigate the soil degradation required by soil managers in this region. The transect approach was applied for sampling to identify the spatial redistribution of (137)Cs. The spatial variability of (137)Cs inventory has provided evidence of the importance of tillage process and the human effects on the redistribution of (137)Cs. The mean (137)Cs inventory was found about 842 Bq m(-2), this value corresponds to an erosion rate of 82 tha(-1) yr(-1) by applying simplified mass balance model in a preliminary estimation. When data on site characteristics were available, the refined mass balance model was applied to highlight the contribution of tillage effect in soil redistribution. The erosion rate was estimated about 50 tha(-1) yr(-1). The aspects related to the sampling procedures and the models for calculation of erosion rates are discussed.

  7. Potential impacts of agricultural expansion and climate change on soil erosion in the Eastern Arc Mountains of Kenya

    NASA Astrophysics Data System (ADS)

    Maeda, Eduardo Eiji; Pellikka, Petri K. E.; Siljander, Mika; Clark, Barnaby J. F.

    2010-11-01

    The Taita Hills form the northernmost part of the Eastern Arc Mountains of Kenya and Tanzania, is one of the world's most important regions for biological conservation. Due to the expansion of agricultural activities during the last centuries, currently only 1% of the original vegetation remains preserved in the Taita Hills. These landscape changes, together with potential increases in rainfall volumes caused by climate change, offer a great risk for soil conservation. The present research aims to evaluate how future changes in climate and land use can alter, in time and space, the variables inherent to a widely used soil erosion model, and to assess the impacts of these changes for soil conservation. A modelling framework was assembled by integrating a landscape dynamic model, a soil erosion model and synthetic precipitation datasets generated through a Monte Carlo simulation. The results indicate that, if the current trends persist, agricultural areas will occupy roughly 60% of the study area by 2030. Although these land use changes will certainly increase soil erosion figures, new croplands will likely take place predominantly in the lowlands, which comprises areas with lower soil erosion potential. By the year 2030, rainfall erosivity is likely to increase during April and November, while a slight decrease tendency is observed during March and May. An integrated assessment of these environmental changes, performed using the modelling framework, allows a clear distinction of priority regions for soil conservation policies during the next 20 years.

  8. Assessment of soil erosion and deposition rates in a Moroccan agricultural field using fallout 137Cs and 210Pbex.

    PubMed

    Benmansour, M; Mabit, L; Nouira, A; Moussadek, R; Bouksirate, H; Duchemin, M; Benkdad, A

    2013-01-01

    In Morocco land degradation - mainly caused by soil erosion - is one of the most serious agroenvironmental threats encountered. However, only limited data are available on the actual magnitude of soil erosion. The study site investigated was an agricultural field located in Marchouch (6°42' W, 33° 47' N) at 68 km south east from Rabat. This work demonstrates the potential of the combined use of (137)Cs, (210)Pb(ex) as radioisotopic soil tracers to estimate mid and long term erosion and deposition rates under Mediterranean agricultural areas. The net soil erosion rates obtained were comparable, 14.3 t ha(-1) yr(-1) and 12.1 ha(-1) yr(-1) for (137)Cs and (210)Pb(ex) respectively, resulting in a similar sediment delivery ratio of about 92%. Soil redistribution patterns of the study field were established using a simple spatialisation approach. The resulting maps generated by the use of both radionuclides were similar, indicating that the soil erosion processes has not changed significantly over the last 100 years. Over the previous 10 year period, the additional results provided by the test of the prediction model RUSLE 2 provided results of the same order of magnitude. Based on the (137)Cs dataset established, the contribution of the tillage erosion impact has been evaluated with the Mass Balance Model 3 and compared to the result obtained with the Mass Balance Model 2. The findings highlighted that water erosion is the leading process in this Moroccan cultivated field, tillage erosion under the experimental condition being the main translocation process within the site without a significant and major impact on the net erosion.

  9. Short-term soil loss by eolian erosion in response to different rain-fed agricultural practices

    NASA Astrophysics Data System (ADS)

    Tanner, Smadar; Katra, Itzhak; Zaady, Eli

    2016-04-01

    Eolian (wind) erosion is a widespread process and a major form of soil degradation in arid and semi-arid regions. The present study examined changes in soil properties and eolian soil loss at a field scale in response to different soil treatments in two rain-fed agricultural practices. Field experiments with a boundary-layer wind tunnel and soil analysis were used to obtain the data. Two practices with different soil treatments (after harvest), mechanical tillage and stubble grazing intensities, were applied in the fallow phase of the rotation (dry season). The mechanical tillage and the stubble grazing had an immediate and direct effects on soil aggregation but not on the soil texture, and the contents of soil water, organic matter, and CaCO3. Higher erosion rates, that was measured as fluxes of total eolian sediment and particulate matter <10 μm (PM10), were recorded under mechanical tillage and grazing intensities compared with the undisturbed topsoil of the control plots. The erosion rates were higher in grazing plots than in tillage plots. The calculated soil fluxes in this study indicate potentially rapid soil degradation due to loss of fine particles by wind. The finding may have implications for long-term management of agricultural soils in semi-arid areas.

  10. Highly erodible terrain in agriculture land against chipped pruned branches. Or how to stop the soil erosion with low investment

    NASA Astrophysics Data System (ADS)

    Cerdà, A.

    2009-04-01

    The session on "Soil erosion and sediment control with vegetation and bioengineering on severely eroded terrain" pays special attention to the severe soil erosion suffered on steep slopes and erodible parent materials and soils. Within the last 20 years, in the Mediterranean lands, the citrus orchards were reallocated on steep slopes due to the urban development and better climatic and management conditions of the new plantations. The lack of vegetation cover on the new slope plantations of citrus resulted in high erosion rates. Those non-sustainable soil losses were measured by means of rainfall simulation experiments, Gerlach collectors, geomorphological transect and topographical measurements. The October 2007 and October 2008 rainy periods resulted in sheet, rill and gully erosion. Some recently planted orchards (2005) had the first pruning season in 2008. The pruned chipped branches reduced the soil losses to 50 % of the expected, although the litter (pruned branches) covered 4.67 % of the soil. This is why a research was developed by means of simulated rainfall experiments to determine the vegetation cover (litter, mainly leaves) to protect the soil to reach a sustainable erosion rate. Rainfall simulation experiments at 43 mm h-1 where performed on 1 m2 plots covered with 0, 3, 7, 15, 30, 45, 60, 80 and 100 % litter cover (pruned chipped branches) to determine the sustainable litter cover to avoid the soil losses. The results show that more that 45 % litter cover almost reduces the soil losses to negligible rates. The results confirm that 4 % of vegetation cover reduces the soil losses to 50 %. Key words: Agriculture land, erodible terrain, land management, citrus, erosion, Spain, Valencia, herbicides. Acknowledgements, We thanks the financial support of the Ministerio de Ciencia e Innovación by means of the project CGL2008-02879/BTE, "PERDIDA DE SUELO EN NUEVAS EXPLOTACIONES CITRICOLAS EN PENDIENTE. ESTRATEGIAS PARA EL CONTROL DE LA EROSION HIDRICA"

  11. 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...

  12. Directional reflectance factors for monitoring spatial changes in soil surface structure and soil organic matter erosion in agricultural systems

    NASA Astrophysics Data System (ADS)

    Croft, H.; Anderson, K.

    2012-04-01

    Soils can experience rapid structural degradation in response to land cover changes, resulting in reduced soil productivity, increased erodibility and a loss of soil organic matter (SOM). The breakdown of soil aggregates through slaking and raindrop impact is linked to organic matter turnover, with subsequently eroded material often displaying proportionally more SOM. A reduction in aggregate stability is reflected in a decline in soil surface roughness (SSR), indicating that a soil structural change can be used to highlight soil vulnerability to SOM loss through mineralisation or erosion. Accurate, spatially-continuous measurements of SSR are therefore needed at a variety of spatial and temporal scales to understand the spatial nature of SOM erosion and deposition. Remotely-sensed data can provide a cost-effective means of monitoring changes in soil surface condition over broad spatial extents. Previous work has demonstrated the ability of directional reflectance factors to monitor soil crusting within a controlled laboratory experiment, due to changes in the levels of self-shadowing effects by soil aggregates. However, further research is needed to test this approach in situ, where other soil variables may affect measured reflectance factors and to investigate the use of directional reflectance factors for monitoring soil erosion processes. This experiment assesses the potential of using directional reflectance factors to monitor changes in SSR, aggregate stability and soil organic carbon (SOC) content for two agricultural conditions. Five soil plots representing tilled and seedbed soils were subjected to different durations of natural rainfall, producing a range of different levels of SSR. Directional reflectance factors were measured concomitantly with sampling for soil structural and biochemical tests at each soil plot. Soil samples were taken to measure aggregate stability (wet sieving), SOC (loss on ignition) and soil moisture (gravimetric method). SSM

  13. The plot size effect on soil erosion on rainfed agriculture land under different land uses in eastern Spain

    NASA Astrophysics Data System (ADS)

    Cerdà, A.; Bodí, M. B.; Burguet, M.; Segura, M.; Jovani, C.

    2009-04-01

    Soil erosion at slope scale is dependent on the size of the plot. This is because soil erosion is a scale-dependent process due to the spatial variability in infiltration, the potential for sediment to be captured by vegetation and other roughness components, and the changes in erosion rates and processes with increasing amounts of runoff. The effects of plot size may also vary with land use, as plot size may be less important in areas with a more homogeneous plant cover or bares soils; meanwhile the soil transmission losses will higher on vegetation covered soils and on patchy distributed plants. A series of study plots were established in 2003 at the El Teularet experimental Station in the Sierra de Enguera in eastern Spain. The overall goal is to assess runoff and erosion rates from different land uses at different spatial scales. Thirteen sets of plots have been established, and each set consists of five adjacent plots that vary in size from 1 m2 (1 x 1 m), 2 m2 (1 x 2 m), 4 m2 (1 x 4 m), 16 m2 (2 x 8 m) and 48 m2 (3 m wide x 16 m length). Each set of plots has a different land use, and the land uses being tested in the first year of this study are fallow, ploughed but unplanted, untilled oats and beans, tilled oats and beans, straw mulch, mulched with chipped olive branches, a geotextile developed to control erosion on agricultural fields, scrub oaks (Quercus coccifera), gorse (Ulex parviflorus), and three herbicide treatments—a systemic herbicide, a contact herbicide, and a persistent herbicide. From those plots, three plots were selected to analyse the effect of the size of the plot on the soil erosion assessment. Herbicide (bare), Catch crops (oat) and scrubland were selected to analyze the soil losses during 2004 and 2005. The results shows that sediment delivery is highly dependent on the land use and land management as the scrubland contributed with null sediment yield, meanwhile the herbicide reached the largest soil loss. The soil erosion was higher

  14. The fate of soil organic carbon upon erosion, transport and deposition in agricultural landscapes - A review of different concepts

    NASA Astrophysics Data System (ADS)

    Kirkels, F. M. S. A.; Cammeraat, L. H.; Kuhn, N. J.

    2014-12-01

    Erosion and deposition redistribute large quantities of sediment and soil organic carbon (SOC) in agricultural landscapes. In the perspective of global carbon cycling, the coupling between erosion processes and the fate of SOC is of particular interest. However, different concepts have been proposed to assess the impact of erosion-induced lateral and vertical carbon fluxes. On landscape scale, this resulted in contrasting conclusions if agricultural soils represent either a carbon sink or source. The large global area of arable soil and generally high erosion rates, make these insights important. In this review, we aim to give an overview of the different conceptual relations described governing C dynamics at sites of erosion, along the transport pathway and at depositional sites and the current state of knowledge on the fate of SOC upon erosion, transport and deposition in agricultural landscapes. The impact of erosion on SOC dynamics differs for sites of erosion, deposition and during transport, with further influences by agricultural practices (e.g. tillage and fertilisation). Controlling processes are the detachment of sediment and SOC, net primary production resulting in dynamic replacement and changes in mineralisation upon transport and deposition due to aggregate breakdown and deep burial, respectively. However, the exact magnitude and dominance of these processes are debated, resulting in a controversy whether arable land functions as a sink or source for atmospheric CO2. Global estimations range between a net sink strength of 0.06-1 versus a source of 0.27-1.14 Gt C yr- 1 for agricultural soils. An eco-geomorphologic approach, which encompasses physical- and biological-driven factors (e.g. spatio-temporal variation in biological, geomorphological and biological processes, environmental conditions, mineralisation, and net primary production) is of importance to balance the carbon budget and ascertain sink or source formation at landscape scale. High spatio

  15. 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…

  16. Mapping of soil erosion and redistribution on two agricultural areas in Czech Republic by using of magnetic parameters.

    NASA Astrophysics Data System (ADS)

    Kapicka, Ales; Stejskalova, Sarka; Grison, Hana; Petrovsky, Eduard; Jaksik, Ondrej; Kodesova, Radka

    2015-04-01

    Soil erosion is one of the major concerns in sustainability of agricultural systems in different areas. Therefore there is a need to develop suitable innovative indirect methods of soil survey. One of this methods is based on well established differentiation in magnetic signature with depth in soil profile. Magnetic method can be applied in the field as well as in the laboratory on collected soil samples. The aim of this study is to evaluate suitability of magnetic method to assess soil degradation and construct maps of cumulative soil loss due to erosion at two morphologically diverse areas with different soil types. Dominant soil unit in the first locality (Brumovice) is chernozem, which is gradually degraded on slopes to regosols. In the second site (Vidim), the dominant soil unit is luvisol, gradualy transformed to regosol due to erosion. Field measurements of magnetic susceptibility were carried out on regular grid, resulting in 101 data points in Brumovice and 65 in Vidim locality. Mass specific magnetic susceptibility χ and its frequency dependence χFD was used to estimate the significance of SP ferrimagnetic particles of pedogenic origin in top soil horizons. Strong correlation was found between the volume magnetic susceptibility (field measurement) and mass- specific magnetic susceptibility measured in the laboratory (Kapicka et al 2013). Values of magnetic susceptibility are spatially distributed depending on terrain position. Higher values were measured at the flat parts (where the original topsoil horizon remained). The lowest values magnetic susceptibility were obtained on the steep valley sides. Here the original topsoil was eroded and mixed by tillage with the soil substrate (loess). Positive correlation between the organic carbon content and volume magnetic susceptibility (R2= 0.89) was found for chernozem area. The differences between the values of susceptibility in the undisturbed soil profile and the magnetic signal after uniform mixing of the

  17. Can conservation trump impacts of climate change and extremes on soil erosion in agricultural landscapes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preservation of top soil is critical for the long term sustainability of agricultural productivity, food security, and biodiversity. However, today’s growing population and increasing demand for food and fiber is stressing the agricultural soil and water resources. Climate change imposes additional ...

  18. The geochemical transformation of soils by agriculture and its dependence on soil erosion: An application of the geochemical mass balance approach.

    PubMed

    Yoo, Kyungsoo; Fisher, Beth; Ji, Junling; Aufdenkampe, Anthony; Klaminder, Jonatan

    2015-07-15

    Agricultural activities alter elemental budgets of soils and thus their long-term geochemical development and suitability for food production. This study examined the utility of a geochemical mass balance approach that has been frequently used for understanding geochemical aspect of soil formation, but has not previously been applied to agricultural settings. Protected forest served as a reference to quantify the cumulative fluxes of Ca, P, K, and Pb at a nearby tilled crop land. This comparison was made at two sites with contrasting erosional environments: relatively flat Coastal Plain in Delaware vs. hilly Piedmont in Pennsylvania. Mass balance calculations suggested that liming not only replenished the Ca lost prior to agricultural practice but also added substantial surplus at both sites. At the relatively slowly eroding Coastal Plain site, the agricultural soil exhibited enrichment of P and less depletion of K, while both elements were depleted in the forest soil. At the rapidly eroding Piedmont site, erosion inhibited P enrichment. In similar, agricultural Pb contamination appeared to have resulted in Pb enrichment in the relatively slowly eroding Coastal Plain agricultural soil, while not in the rapidly eroding Piedmont soils. We conclude that agricultural practices transform soils into a new geochemical state where current levels of Ca, P, and Pb exceed those provided by the local soil minerals, but such impacts are significantly offset by soil erosion. PMID:25847176

  19. Using 137Cs to study spatial patterns of soil erosion and soil organic carbon (SOC) in an agricultural catchment of the typical black soil region, Northeast China.

    PubMed

    Fang, Haiyan; Li, Qiuyan; Sun, Liying; Cai, Qiangguo

    2012-10-01

    Understanding the spatial pattern of soil organic carbon (SOC) is of great importance because of global environmental concerns. Soil erosion and its subsequent redistribution contribute significantly to the redistribution of SOC in agricultural ecosystems. This study investigated the relationships between (137)Cs and SOC over an agricultural landscape, and SOC redistribution was conducted for an agricultural catchment of the black soil region in Northeast China. The spatial patterns of (137)Cs and SOC were greatly affected by the established shelterbelts and the developed ephemeral gullies. (137)Cs were significantly correlated with SOC when (137)Cs were >2000 Bq m(-2), while no relation was observed between them when (137)Cs were <2000 Bq m(-2). Factors other than soil erosion such as vegetative productivity, mineralization of SOC, landscape position and management induced their spatial difference of (137)Cs and SOC. Using (137)Cs technique to directly study SOC dynamics must be cautious in the black soils. The net SOC loss rate across the entire catchment during 1954-2010 was 92.8 kg ha(-1) yr(-1), with around 42% of the eroded SOC being redeposited within the catchment. Such information can help guide shelterbelt establishment or other land management to reduce SOC loss in the agricultural ecosystems.

  20. Assessing the impacts of agricultural change on soil erosion over the last century: a multi-model ensemble approach

    NASA Astrophysics Data System (ADS)

    Sellami, Haykel; Smith, Hugh; Sangster, Heather; Riley, Mark; Chiverrell, Richard; Boyle, John

    2016-04-01

    Soil erosion models (SEMs) are valuable tools for understanding the links between past agricultural practices and soil erosion. Use of SEMs allows assessment of impacts from agricultural change over timescales that exceed instrumental records but correspond to periods for which considerable land use and climate information are available. Here, we develop a modelling framework to investigate the potential impacts of changes in agricultural practices and climate on soil erosion and sediment transport over the last 100 years in six lake catchments in Britain spanning upland and lowland environments. The modelling platform comprises a multi-model ensemble of derivatives of the Morgan-Morgan-Finney (MMF) and RUSLE models. Simulation of change in land use/land cover (LULC), drainage features, crop rotation and livestock grazing are accounted for by reconstructing LULC maps from 1888 to 2007. Reconstructions of climatic conditions combine multiple records using regression and artificial neural network techniques to derive long-term daily precipitation and temperature series from 1880 to present. The modelling platform uses a grid-based modelling approach to handle the spatial distribution and heterogeneity in LULC, soil and topographic information. For each soil type, a database of physical parameters was created by combining information from the literature, LandIS soil database and pedotransfer functions. At each grid cell, a rainfall-Runoff (RR) model based on saturation excess runoff generation mechanisms provides daily soil moisture content. Furthermore, the modelling platform encompasses a crop cover model (CC) based on the Heat Unit approach developed to simulate daily Leaf Area Index for each crop type. Both the RR and CC models are used to update the canopy and ground cover parameters. In the absence of long-term river monitoring data, lake sediment records are used to compare the multi-model simulations thus creating a baseline from which to project impacts from

  1. Detection of erosion events using 10Be profiles: example of the impact of agriculture on soil erosion in the Chesapeake Bay area (U.S.A.)

    USGS Publications Warehouse

    Valette-Silver, J. N.; Brown, L.; Pavich, M.; Klein, J.; Middleton, R.

    1986-01-01

    10Be concentration, total carbon and grain-size were measured in cores collected in undisturbed estuarine sediments of three tributaries of the Chesapeake Bay. These cores were previously studied by Davis [1] and Brush [2,3] for pollen content, age and sedimentation rate. In this work, we compare the results obtained for these various analyses. In the cores, we observed two increases in 10Be concentration concomitant with two major changes in the pollen composition of the sediments. These two pollen changes each correspond to well-dated agricultural horizons reflecting different stages in the introduction of European farming techniques [2]. In the Chesapeake Bay area, the agricultural development, associated with forest clearing, appears to have triggered the erosion, transport, and sedimentation into the river mouths of large quantities of 10Be-rich soils. This phenomenon explains the observed rise in the sedimentation rate associated with increases in agricultural land-use. ?? 1986.

  2. A comparison of rating and dating techniques to estimate the threat of soil erosion to archaeological monuments under agricultural fields

    NASA Astrophysics Data System (ADS)

    van Soest, Maud; Huisman, Hans; Schoorl, Jeroen; Reimann, Tony; Temme, Arnaud; Wallinga, Jakob; de Kort, Jan-Willem; van der Heiden, Menno; van Os, Bertil; van Egmond, Fenny; Ketteren, Michael

    2015-04-01

    For the protection of Dutch archaeological sites against degradation, the TOPsites project is investigating the rate, extent and mitigation of the most important processes involved. One of these processes is soil translocation or soil redistribution. For many Dutch archaeological sites the actual extent and rate of soil erosion is not yet known. In this study different techniques for dating and estimating rates have been compared on three archaeological sites on tilled fields with gentle slopes: (multi-temporal LiDar, profiles and spatial distribution of 137Cs, anthropogenic Pb, and 239+240Pu, and moreover OSL. In addition, the added value of the combination of several of these techniques together will be evaluated. Preliminary results show evidence for colluvium formation (deposition) on two of the sites. Lead contents in a buried soil on one of these sites suggest a subrecent to recent date. 137Cs profiles and spatial mapping, however, do not show clear evidence for recent erosion or re-deposition patterns. These first results suggest that in these agricultural settings with typical Dutch gentle slopes, erosion may only occur in rare, catastrophic, events with local high erosion and re-deposition rates instead of a more or less continuous process with lower rates. Consequently, the impact of ploughing might be limited to mixing of the plough layer, while the effect of damaging soil translocation, for these selected archaeological sites, seems less important. Forthcoming analysis and results of Pu and OSL will provide enough data for further discussion and possible falsification of these preliminary conclusions.

  3. 3-D modeling of water balance and soil erosion in a clayey subsurface drained agricultural field in boreal climate

    NASA Astrophysics Data System (ADS)

    Turunen, M.; Warsta, L.; Koivusalo, H. J.; Paasonen-Kivekäs, M.; Nurminen, J.; Myllys, M.; Alakukku, L.; Äijö, H.; Puustinen, M.

    2012-12-01

    Fluxes of nutrients and other substances from cultivated fields cause eutrophication and deterioration of water quality in aquatic ecosystems worldwide. In order to develop effective strategies to control the environmental impacts of crop cultivation, it is crucial to identify the main transport pathways and the effects of different water management methods on the loads. Reduction of sediment loads is essential since sediment particles typically carry nutrients (especially sorbed phosphorus) and other potentially harmful substances, e.g. pesticides, from the fields to the adjacent surface waters. The novel part of this study was the investigation of suspended sediment transport in soil macropores to the subsurface drains and to the deep groundwater. We applied a 3-D distributed dual-permeability model (FLUSH) using a dataset collected from a subsurface drained, clayey agricultural field (15 ha) to holistically assess water balance, soil erosion and sediment transport from the field to an adjacent stream. The data set included five years of hydrological and water quality measurements from four intensively monitored field sections with different soil properties, topography, drainage systems (drain spacing and drain depth), drain installation methods (trenchless and trench drainage) and drain envelope materials (gravel and fiber). The 3-D model allowed us to quantify how soil erosion and sediment transport differed between the field sections within the field area. The simulations were conducted during snow- and frost-free periods. The simulation results include closure of water balance of the cultivated field, distribution of soil erosion and sediment transport within the field area and the effects of different subsurface drainage systems on sediment loads. The 3-D dual-permeability subsurface flow model was able to reproduce the measured drainflows and sediment fluxes in the clayey field and according to the simulations over 90% of drainflow waters were conveyed to

  4. A finite element model for simulating runoff and soil erosion from mechanically treated agricultural lands: 2. Field validation and applications

    NASA Astrophysics Data System (ADS)

    Sharda, V. N.; Singh, Sita Ram; Sastry, G.; Dhruvanarayana, V. V.

    1994-07-01

    The finite element model for simulation of runoff and soil erosion as developed by Sharda and Singh (this issue) is evaluated using data collected from agricultural land treated with major mechanical soil and water conservation measures, namely, contour bunding, graded bunding, bench terracing, and conservation bench terracing. The simulated and experimentally realized hydrographs and soil loss values are in reasonably good agreement for various measures. Probable reasons for discrepancies between the predicted and observed values are discussed. The model has the potential of being used on a single storm or a continuous basis provided the soil, crop, and climatic parameters are precisely known or estimated for a given location and for the period under consideration. The model logically simulates the effects of flow, topographic, soil, and crop parameters such as antecedent moisture level, roughness coefficient, saturated hydraulic conductivity, slope, depth of impoundment, size of outlet, longitudinal slope of the channel, vertical interval, and cropping management factor. The model is found to be quite sensitive to changes in roughness coefficient, rainfall excess rate, and cover management factor, and hence these parameters need to be assessed carefully in the field. The general applicability of the model as a planning tool for soil conservation measures and the scope for future development are also discussed.

  5. Wind, rain and soil erosion rates on bare and plant covered agriculture plots at the experimental station of El Teularet -Sierra de Enguera, Eastern Spain

    NASA Astrophysics Data System (ADS)

    Cerdà, A.; Azorin-Molina, C.; Iserloh, Th.

    2012-04-01

    Soil erosion is being scientifically researched for more tan one century, but there is some knowledge lacks that should be researched. Within the factors of the soil erosion wind and rain were studied, but little is know about the impact of the combination of both. Soil erosion by wind was mainly studied on drylands and agriculture land (Sterk and Spaan, 1997; Bielders et al., 2002; Rajot et al., 2003; Zobeck et al., 2003). Soil erosion by water was studied in many ecosystems but it is especially active on agriculture land (Cerdà et al., 2009) and under Mediterranean climatic conditions (Cerdà et al., 2010). The importance of wind on soil erosion is base in the fact that rainstorms occurs with wind, adding a driving component to the falling raindrops. The influence of wind on raindrops is clear, but there is not measurements and there is no information of this influence under field conditions with natural rainfall events.This paper aims to determine the interaction between wind and rain as factors of the soil losses under Mediterranean climatic conditions and different agriculture managements and land uses. Since 2003, the El Teularet-Serra de Enguera Soil Erosion Experimental Station located in Eastern Spain is measuring the soil losses in plots under different land uses and land managements. The station is devoted to study the soil water erosion processes under rain-fed agriculture fields and the rangelands by means of simulated rainfall experiments and plots of different sizes. The soil erosion measure ments are done by means of 13 plots, each of them composed of 5 subplots of 1, 2, 4, 16 and 48 m2 under different land uses and managements. Two plots are covered by two different types of shrubs: Quercus coccifera and Ulex parviflorus, respectively. Three plots reproduce the use of herbicides, one is ploughed, and three plots follow conservation practices (oats and beans with no-tillage, with tillage, and with a vege- tation cover of weeds). Other plots are

  6. 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.

  7. 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

  8. Quantitative Assessment of Agricultural Runoff and Soil Erosion Using Mathematical Modeling: Applications in the Mediterranean Region

    NASA Astrophysics Data System (ADS)

    Arhonditsis, G.; Giourga, C.; Loumou, A.; Koulouri, M.

    2002-09-01

    Three mathematical models, the runoff curve number equation, the universal soil loss equation, and the mass response functions, were evaluated for predicting nonpoint source nutrient loading from agricultural watersheds of the Mediterranean region. These methodologies were applied to a catchment, the gulf of Gera Basin, that is a typical terrestrial ecosystem of the islands of the Aegean archipelago. The calibration of the model parameters was based on data from experimental plots from which edge-of-field losses of sediment, water runoff, and nutrients were measured. Special emphasis was given to the transport of dissolved and solid-phase nutrients from their sources in the farmers' fields to the outlet of the watershed in order to estimate respective attenuation rates. It was found that nonpoint nutrient loading due to surface losses was high during winter, the contribution being between 50% and 80% of the total annual nutrient losses from the terrestrial ecosystem. The good fit between simulated and experimental data supports the view that these modeling procedures should be considered as reliable and effective methodological tools in Mediterranean areas for evaluating potential control measures, such as management practices for soil and water conservation and changes in land uses, aimed at diminishing soil loss and nutrient delivery to surface waters. Furthermore, the modifications of the general mathematical formulations and the experimental values of the model parameters provided by the study can be used in further application of these methodologies in watersheds with similar characteristics.

  9. Quantitative assessment of agricultural runoff and soil erosion using mathematical modeling: applications in the Mediterranean region.

    PubMed

    Arhonditsis, G; Giourga, C; Loumou, A; Koulouri, M

    2002-09-01

    Three mathematical models, the runoff curve number equation, the universal soil loss equation, and the mass response functions, were evaluated for predicting nonpoint source nutrient loading from agricultural watersheds of the Mediterranean region. These methodologies were applied to a catchment, the gulf of Gera Basin, that is a typical terrestrial ecosystem of the islands of the Aegean archipelago. The calibration of the model parameters was based on data from experimental plots from which edge-of-field losses of sediment, water runoff, and nutrients were measured. Special emphasis was given to the transport of dissolved and solid-phase nutrients from their sources in the farmers' fields to the outlet of the watershed in order to estimate respective attenuation rates. It was found that nonpoint nutrient loading due to surface losses was high during winter, the contribution being between 50% and 80% of the total annual nutrient losses from the terrestrial ecosystem. The good fit between simulated and experimental data supports the view that these modeling procedures should be considered as reliable and effective methodological tools in Mediterranean areas for evaluating potential control measures, such as management practices for soil and water conservation and changes in land uses, aimed at diminishing soil loss and nutrient delivery to surface waters. Furthermore, the modifications of the general mathematical formulations and the experimental values of the model parameters provided by the study can be used in further application of these methodologies in watersheds with similar characteristics.

  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. Analyzing soil erosion using a multi-temporal UAV data set after one year of active agriculture in Navarra, Spain

    NASA Astrophysics Data System (ADS)

    Anders, Niels; Keesstra, Saskia; Masselink, Rens

    2014-05-01

    Unmanned Aerial System (UAS) are becoming popular tools in the geosciences due to improving technology and processing/analysis techniques. They can potentially fill the gap between spaceborne or manned aircraft remote sensing and terrestrial remote sensing, both in terms of spatial and temporal resolution. In this study we analyze a multi-temporal data set that was acquired with a fixed-wing UAS in an agricultural catchment (2 sq. km) in Navarra, Spain. The goal of this study is to register soil erosion activity after one year of agricultural activity. The aircraft was equipped with a Panasonic GX1 16MP pocket camera with a 20 mm lens to capture normal JPEG RGB images. The data set consisted of two sets of imagery acquired in the end of February in 2013 and 2014 after harvesting. The raw images were processed using Agisoft Photoscan Pro which includes the structure-from-motion (SfM) and multi-view stereopsis (MVS) algorithms producing digital surface models and orthophotos of both data sets. A discussion is presented that is focused on the suitability of multi-temporal UAS data and SfM/MVS processing for quantifying soil loss, mapping the distribution of eroded materials and analyzing re-occurrences of rill patterns after plowing.

  12. Fuzzy Representation of Soil Erosion

    NASA Astrophysics Data System (ADS)

    Komaki, Ch. B.; Kainz, W.; Alavi Panah, S. K.; Matinfar, H. R.

    2009-04-01

    Fuzzy representation is a productive method to explain the natural processes so that it is near to linguistic form and it is also applicable to estimate the environmental processes in where the uncertainty in information is high. As models proposed to estimate soil erosion also have uncertainties and fuzzy inference system is more flexible in describing the relationship between soil erosion and other factor, especially in managing data and model uncertainties. in the research, it is used simplified model of revised Universal Soil Loss Equation (RUSLE) to estimate soil erosion in dry lands of Kashan area in Central Iran . Then to discover the systematic (IF-Then) rules in soil erosion process, we used inductive reasoning method to discover rules of the causing agents of erosion such as rainfall erosivity, topography factors, soil erodibility , then highly supported rules converted to fuzzy rules. It is resulted that the application of fuzzy inference system for erosion evaluation is applicable in regional level.

  13. Tolerable soil erosion in Europe

    NASA Astrophysics Data System (ADS)

    Verheijen, Frank; Jones, Bob; Rickson, Jane; Smith, Celina

    2010-05-01

    Soil loss by erosion has been identified as an important threat to soils in Europe* and is recognised as a contributing process to soil degradation and associated deterioration, or loss, of soil functioning. From a policy perspective, it is imperative to establish well-defined baseline values to evaluate soil erosion monitoring data against. For this purpose, accurate baseline values - i.e. tolerable soil loss - need to be differentiated at appropriate scales for monitoring and, ideally, should take soil functions and even changing environmental conditions into account. The concept of tolerable soil erosion has been interpreted in the scientific literature in two ways: i) maintaining the dynamic equilibrium of soil quantity, and ii) maintaining biomass production, at a location. The first interpretation ignores soil quality by focusing only on soil quantity. The second approach ignores many soil functions by focusing only on the biomass (particularly crop) production function of soil. Considering recognised soil functions, tolerable soil erosion may be defined as 'any mean annual cumulative (all erosion types combined) soil erosion rate at which a deterioration or loss of one or more soil functions does not occur'. Assumptions and problems of this definition will be discussed. Soil functions can generally be judged not to deteriorate as long as soil erosion does not exceed soil formation. At present, this assumption remains largely untested, but applying the precautionary principle appears to be a reasonable starting point. Considering soil formation rates by both weathering and dust deposition, it is estimated that for the majority of soil forming factors in most European situations, soil formation rates probably range from ca. 0.3 - 1.4 t ha-1 yr-1. Although the current agreement on these values seems relatively strong, how the variation within the range is spatially distributed across Europe and how this may be affected by climate, land use and land management

  14. 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 ...

  15. A methodological approach for deriving regional crop rotations as basis for the assessment of the impact of agricultural strategies using soil erosion as example.

    PubMed

    Lorenz, Marco; Fürst, Christine; Thiel, Enrico

    2013-09-01

    Regarding increasing pressures by global societal and climate change, the assessment of the impact of land use and land management practices on land degradation and the related decrease in sustainable provision of ecosystem services gains increasing interest. Existing approaches to assess agricultural practices focus on the assessment of single crops or statistical data because spatially explicit information on practically applied crop rotations is mostly not available. This provokes considerable uncertainties in crop production models as regional specifics have to be neglected or cannot be considered in an appropriate way. In a case study in Saxony, we developed an approach to (i) derive representative regional crop rotations by combining different data sources and expert knowledge. This includes the integration of innovative crop sequences related to bio-energy production or organic farming and different soil tillage, soil management and soil protection techniques. Furthermore, (ii) we developed a regionalization approach for transferring crop rotations and related soil management strategies on the basis of statistical data and spatially explicit data taken from so called field blocks. These field blocks are the smallest spatial entity for which agricultural practices must be reported to apply for agricultural funding within the frame of the European Agricultural Fund for Rural Development (EAFRD) program. The information was finally integrated into the spatial decision support tool GISCAME to assess and visualize in spatially explicit manner the impact of alternative agricultural land use strategies on soil erosion risk and ecosystem services provision. Objective of this paper is to present the approach how to create spatially explicit information on agricultural management practices for a study area around Dresden, the capital of the German Federal State Saxony.

  16. 7 CFR 610.12 - Equations for predicting soil loss due to water erosion.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 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...

  17. 7 CFR 610.12 - Equations for predicting soil loss due to water erosion.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 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...

  18. 7 CFR 610.12 - Equations for predicting soil loss due to water erosion.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 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...

  19. 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...

  20. 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...

  1. Erosion and stability of a mine soil

    SciTech Connect

    Wu, T.H.; Stadler, A.T.; Low, C.

    1996-06-01

    Mine soils developed from mine spoils commonly have a wide range of particle size. The slopes of old spoil piles usually are marked by gullies due to years of uncontrolled erosion. These characteristics raise questions about applicability of available theories and models for estimating runoff and erosion. An investigation was made to determine whether available erosion models can work for mine soils and can account for gully erosion. The investigation at an abandoned surface mine consisted of measurement of soil and sediment properties, measurement of runoff and erosion, observations of armor by rock fragments on gully floor, and calculations with available theories of sediment transport and slope stability. The results at this site suggest that (1) predictions with the ANSWERS model have about the same accuracy as those made for agricultural lands; (2) armor provided by rock fragments are temporary as they are periodically removed by debris flows; (3) detachment by rainfall impact is the primary cause of erosion on short steep slopes; and (4) a simplified method can be used for estimating erosion on such slopes.

  2. 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...

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

    USGS Publications Warehouse

    Van Oost, Kristof; Van Hemelryck, Hendrik; Harden, Jennifer W.; McPherson, B.J.; Sundquist, E.T.

    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.

  4. Coupling a high resolution soil erosion model with an agro-ecosystem model of SOC dynamics. An approach to assess the potential environmental effect of the new Common Agricultural Policy on soil degradation

    NASA Astrophysics Data System (ADS)

    Borrelli, Pasqualle; Paustian, Keith; Panagos, Panos; Jones, Arwyn; Schütt, Brigitta; Lugato, Emanuele

    2016-04-01

    At the European Union level, the main mechanisms to promote a more sustainable and environmentally friendly agriculture was introduced by the Common Agricultural Policy (CAP) reform in 2003, through the Cross-compliance. According to this new regulation, the farmer support payments were regulated with respect to environmental, animal welfare and food safety standards. This brought to the Good Agricultural and Environmental Conditions (GAEC), firstly established by Council Regulation No. 1782/2003 and subsequently Council Regulation (EC) No 73/2009. The prevention of soil erosion and maintenance of soil organic matter were two of GAEC requirements, which each Member State was obliged to address through national standards such as: i) minimal soil cover maintenance (GAEC 4); ii) minimum land management reflecting site specific conditions to limit soil loss (GAEC 5) and iii) maintenance of soil organic matter level through appropriate practices including ban on burning arable stubbles (GAEC 6). Although Member States are required to verify whether the farmers are compliant with the regulations (Cross-compliance), the environmental effect of Good Agricultural and Environmental Conditions (GAEC) applications on erosion and carbon budgets are still little known and studied. To investigate the potential impacts of the GAEC, we coupled a high resolution erosion model based on Revised Universal Soil Loss Equation (RUSLE) with the CENTURY biogeochemical model (Land Use Policy, 50, 408-421; 2016). The Italian arable land was selected as a study area, since it is well-known to be highly sensitive to soil erosion. Multi scenario modelling approach was undertaken, i.e., i) a baseline scenario without scenario excluding GAEC (pre 2003 period); ii) a present scenario including the current GAEC standards (post 2003 period), and iii) a technical potential scenario assuming that the GAEC standards were applied to the entire Italian arable land. The results show a 10.8% decrease, from

  5. Soil erosion in Iran: Issues and solutions

    NASA Astrophysics Data System (ADS)

    Hamidreza Sadeghi, Seyed; Cerdà, Artemi

    2015-04-01

    scale using the Taguchi method. Journal of Hydrology, 448, 174-180. Asadi, H., Moussavi, A., Ghadiri, H., Rose, C. W. 2011. Flow-driven soil erosion processes and the size selectivity of sediment. Journal of Hydrology, 406(1), 73-81. Asadi, H., Raeisvandi, A., Rabiei, B., Ghadiri, H. 2012. Effect of land use and topography on soil properties and agronomic productivity on calcareous soils of a semiarid region, Iran. Land Degradation & Development, 23(5), 496-504. Ayoubi, S., Ahmadi, M., Abdi, M. R., Abbaszadeh Afshar, F. 2012. Relationships of< sup> 137 Cs inventory with magnetic measures of calcareous soils of hilly region in Iran. Journal of environmental radioactivity, 112, 45-51. Ayoubi, S., Mokhtari Karchegani, P., Mosaddeghi, M. R., Honarjoo, N. 2012. Soil aggregation and organic carbon as affected by topography and land use change in western Iran. Soil and Tillage Research, 121, 18-26. Emadodin, I., Bork, H. R. 2012. Degradation of soils as a result of long-term human-induced transformation of the environment in Iran: an overview. Journal of Land Use Science, 7(2), 203-219. Emadodin, I., Narita, D., Bork, H. R. 2012. Soil degradation and agricultural sustainability: an overview from Iran. Environment, Development and Sustainability, 14(5), 611-625. Haddadchi, A., Nosrati, K., Ahmadi, F. 2014. Differences between the source contribution of bed material and suspended sediments in a mountainous agricultural catchment of western Iran. CATENA, 116, 105-113. Heshmati, M., Arifin, A., Shamshuddin, J., Majid, N. M. 2012. Predicting N, P, K and organic carbon depletion in soils using MPSIAC model at the Merek catchment, Iran. Geoderma, 175, 64-77. Jafari, R., Bakhshandehmehr, L. 2013. Quantitative mapping and assessment of environmentally sensitive areas to desertification in central Iran. Land Degradation & Development.DOI: 10.1002/ldr.2227 Kavian, A., Azmoodeh, A., Solaimani, K. 2014. Deforestation effects on soil properties, runoff and erosion in northern Iran. Arabian

  6. Uncertainty in soil carbon accounting due to unrecognized soil erosion.

    PubMed

    Sanderman, Jonathan; Chappell, Adrian

    2013-01-01

    The movement of soil organic carbon (SOC) during erosion and deposition events represents a major perturbation to the terrestrial carbon cycle. Despite the recognized impact soil redistribution can have on the carbon cycle, few major carbon accounting models currently allow for soil mass flux. Here, we modified a commonly used SOC model to include a soil redistribution term and then applied it to scenarios which explore the implications of unrecognized erosion and deposition for SOC accounting. We show that models that assume a static landscape may be calibrated incorrectly as erosion of SOC is hidden within the decay constants. This implicit inclusion of erosion then limits the predictive capacity of these models when applied to sites with different soil redistribution histories. Decay constants were found to be 15-50% slower when an erosion rate of 15 t soil ha(-1)  yr(-1) was explicitly included in the SOC model calibration. Static models cannot account for SOC change resulting from agricultural management practices focused on reducing erosion rates. Without accounting for soil redistribution, a soil sampling scheme which uses a fixed depth to support model development can create large errors in actual and relative changes in SOC stocks. When modest levels of erosion were ignored, the combined uncertainty in carbon sequestration rates was 0.3-1.0 t CO2  ha(-1)  yr(-1) . This range is similar to expected sequestration rates for many management options aimed at increasing SOC levels. It is evident from these analyses that explicit recognition of soil redistribution is critical to the success of a carbon monitoring or trading scheme which seeks to credit agricultural activities.

  7. The relative importance of fertilization and soil erosion on C-dynamics in agricultural landscapes of NE Germany

    NASA Astrophysics Data System (ADS)

    Pohl, Madlen; Hoffmann, Mathias; Hagemann, Ulrike; Jurisch, Nicole; Remus, Rainer; Sommer, Michael; Augustin, Jürgen

    2016-04-01

    The hummocky ground moraine landscape of north-east Germany is characterized by distinct small-scale soil heterogeneity on the one hand, and intensive energy crop cultivation on the other. Both factors are assumed to significantly influence gaseous C exchange, and thus driving the dynamics of soil organic carbon stocks in terrestrial, agricultural ecosystems. However, it is not yet clear to which extent fertilization and soil erosional status influence soil C dynamics and whether one of these factors is more relevant than the other. We present seasonal and dynamic soil C balances of biogas maize for the growing season 2011, recorded at different sites located within the CarboZALF experimental area. The sites differ regarding soils (non-eroded Albic Luvisols (Cutanic), extremely eroded Calcaric Regosol and depositional Endogleyic Colluvic Regosol,) and applied fertilizer (100% mineral N fertilizer, 50% mineral and 50% N organic fertilizer, 100% organic N fertilizer). Fertilization treatments were established on the Albic Luvisol (Cutanic). Net-CO2-exchange (NEE) and ecosystem respiration (Reco) were measured every four weeks using a dynamic flow-through non-steady-state closed manual chamber system. Gap filling was performed based on empirical temperature and PAR dependency functions to derive daily NEE values. At the same time, daily above-ground biomass production (NPP) was estimated based on biomass samples and final harvest, using a sigmoidal growth function. In a next step, dynamic soil C balances were generated as the balance of daily NEE and NPP considering the initial C input due to N fertilizers. The resulted seasonal soil C balances varied from strong C losses at the Endogleyic Colluvic Regosol (602 g C m-2) to C gains at the Calcaric Regosol (-132 g C m-2). In general, soils exerted a stronger impact on seasonal and dynamic C balances compared to differences in applied N fertilizer. There are indications that inter-annual variations in climate conditions

  8. 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.

  9. 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.…

  10. 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)....

  11. 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)....

  12. 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... 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)....

  13. 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... 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)....

  14. 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... 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)....

  15. 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

  16. 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.

  17. 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,...

  18. Understanding the role of soil erosion on co2-c loss using (13)c isotopic signatures in abandoned Mediterranean agricultural land.

    PubMed

    Novara, Agata; Keesstra, Saskia; Cerdà, Artemio; Pereira, Paulo; Gristina, Luciano

    2016-04-15

    Understanding soil water erosion processes is essential to evaluate the redistribution of soil organic carbon (SOC) within a landscape and is fundamental to assess the role of soil erosion in the global carbon (C) budget. The main aim of this study was to estimate the C redistribution and losses using (13)C natural abundance. Carbon losses in soil sediment, dissolved organic carbon (DOC) and CO2 emission were determined. Four bounded parallel plots were installed on a 10% slope. In the upper part of the plots, C3soil was replaced with C4soil. The SOC and δ(13)C were measured after 145.2mm rainfall in the upper (2m far from C4strip), middle (4m far from C4strip) lower (6m far from C4strip) trams of the plot and in the sediments collected in the Gerlach collector at the lower part of the plot. A laboratory incubation experiment was performed to evaluate the CO2 emission rate of soils in each area. OC was mainly lost in the sediments as 2.08g(-)(2) of C was lost after 145.2mm rainfall. DOC losses were only 5.61% of off-site OC loss. Three months after the beginning of the experiment, 15.90% of SOC in the upper tram of the plot had a C4 origin. The C4-SOC content decreased along the 6m length of the plot, and in the sediments collected by the Gerlach collector. CO2 emission rate was high in the upper plot tram due to the high SOC content. The discrimination of CO2 in C3 and C4 portion permitted to increase our level of understanding on the stability of SOC and its resilience to decomposition. The transport of sediments along the plot increased SOC mineralization by 43%. Our study underlined the impact of rainfall in C losses in soil and water in abandoned Mediterranean agriculture fields and the consequent implications on the C balance.

  19. Understanding the role of soil erosion on co2-c loss using (13)c isotopic signatures in abandoned Mediterranean agricultural land.

    PubMed

    Novara, Agata; Keesstra, Saskia; Cerdà, Artemio; Pereira, Paulo; Gristina, Luciano

    2016-04-15

    Understanding soil water erosion processes is essential to evaluate the redistribution of soil organic carbon (SOC) within a landscape and is fundamental to assess the role of soil erosion in the global carbon (C) budget. The main aim of this study was to estimate the C redistribution and losses using (13)C natural abundance. Carbon losses in soil sediment, dissolved organic carbon (DOC) and CO2 emission were determined. Four bounded parallel plots were installed on a 10% slope. In the upper part of the plots, C3soil was replaced with C4soil. The SOC and δ(13)C were measured after 145.2mm rainfall in the upper (2m far from C4strip), middle (4m far from C4strip) lower (6m far from C4strip) trams of the plot and in the sediments collected in the Gerlach collector at the lower part of the plot. A laboratory incubation experiment was performed to evaluate the CO2 emission rate of soils in each area. OC was mainly lost in the sediments as 2.08g(-)(2) of C was lost after 145.2mm rainfall. DOC losses were only 5.61% of off-site OC loss. Three months after the beginning of the experiment, 15.90% of SOC in the upper tram of the plot had a C4 origin. The C4-SOC content decreased along the 6m length of the plot, and in the sediments collected by the Gerlach collector. CO2 emission rate was high in the upper plot tram due to the high SOC content. The discrimination of CO2 in C3 and C4 portion permitted to increase our level of understanding on the stability of SOC and its resilience to decomposition. The transport of sediments along the plot increased SOC mineralization by 43%. Our study underlined the impact of rainfall in C losses in soil and water in abandoned Mediterranean agriculture fields and the consequent implications on the C balance. PMID:26820936

  20. Heterogeneity and topsoil depletion due to tillage erosion and soil co-extraction with root vegetables: a serious threat to sustainable agricultural land use in the UK

    NASA Astrophysics Data System (ADS)

    Quine, Timothy; van Oost, Kristof

    2010-05-01

    The term soil erosion has become almost synonymous with water erosion and yet tillage erosion and soil loss with root crop harvest, although less visible, may be responsible for the majority of the on-site costs of soil erosion in many arable areas of the UK. The study reported here is a first attempt to model soil erosion associated with these processes in England and Wales, at the National scale. A GIS-based modelling approach in the Arc/Info environment is employed in order to meet the requirement for large-scale evaluation of erosion severity. Existing models that have been subject to independent test are used or adapted and widely available data is employed in model parameterisation. Tillage erosion is simulated using a diffusion-type model and a slope curvature index derived from coarse-scale topographic data. The curvature index is calibrated by statistical comparison to curvature values derived from a high resolution digital terrain model. Soil loss with root crop harvest is simulated using information concerning patterns of sugar beet and potato cultivation and estimation of soil moisture during the crop harvest season. Soil loss associated with root crop harvest may be as high as 1 t ha-1 year-1 if land is permanently used for root crops in a 3 year rotation. However, when the arable area of the UK is considered as a whole root crop harvest is responsible for a mean rate of soil loss of approximately 0.1 t ha-1 year-1. Tillage erosion is found to be the dominant process of soil redistribution and onsite erosion on arable land, in comparison with both soil loss through root crop harvest and with long-term water erosion rates. Mean gross rates of tillage erosion were found to be 3.7 t ha-1 year-1, representing approximately 7.4 t ha-1 year-1 erosion and the same rate of deposition. Soil redistribution at these rates is generating an heterogeneous soilscape in which continued functioning for food and fibre production may be jeopardized. These problems may be

  1. Water erosion as a cause for agricultural soil loss: modeling of dynamic processes using high-resolution ground based LiDAR measurements

    NASA Astrophysics Data System (ADS)

    Oz, Imri; Filin, Sagi; Assouline, Shmuel; Shtain, Zachi; Furman, Alexander

    2016-04-01

    Soil erosion by rainfall and water flow is a frequent natural geomorphic process shaping the earth's surface at various scales. Conventional agrotechnical methods enhance soil erosion at the field scale and are at the origin of the reduction of the upper soil layer depth. This reduction is expressed in two aspects: decrease of soil depth, mainly due to erosion, and the diminution of soil quality, mainly due to the loss of fine material, nutrients and organic matter. Rain events, not even the most extremes, cause detachment and transport of fertile soil rich in organic matter and nutrients away from the fields, filling and plugging drainage channels, blocking infrastructure and contaminating water sources. Empirical, semi-empirical and mechanistic models are available to estimate soil erosion by water flow and sediment transport (e.g. WEPP, KINEROSS, EUROSEM). Calibration of these models requires data measured at high spatial and temporal resolutions. Development of high-resolution measurement tools (for both spatial and temporal aspects) should improve the calibration of functions related to particles detachment and transport from the soil surface. In addition, despite the great impact of different tillage systems on the soil erosion process, the vast majority of the models ignore this fundamental factor. The objective of this study is to apply high-resolution ground-based LiDAR measurements to different tillage schemes and scales to improve the ability of models to accurately describe the process of soil erosion induced by rainfall and overland flow. Ground-based laser scans provide high resolution accurate and subtle geomorphic changes, as well as larger-scale deformations. As such, it allows frequent monitoring, so that even the effect of a single storm can be measured, thus improving the calibration of the erosion models. Preliminary results for scans made in the field show the potential and limitations of ground-based LiDAR, and at this point qualitatively can

  2. Soil erosion dynamics response to landscape pattern.

    PubMed

    Ouyang, Wei; Skidmore, Andrew K; Hao, Fanghua; Wang, Tiejun

    2010-02-15

    Simulating soil erosion variation with a temporal land use database reveals long-term fluctuations in landscape patterns, as well as priority needs for soil erosion conservation. The application of a multi-year land use database in support of a Soil Water Assessment Tool (SWAT) led to an accurate assessment, from 1977 to 2006, of erosion in the upper watershed of the Yellow River. At same time, the impacts of land use and landscape service features on soil erosion load were assessed. A series of supervised land use classifications of Landsat images characterized variations in land use and landscape patterns over three decades. The SWAT database was constructed with soil properties, climate and elevation data. Using water flow and sand density data as parameters, regional soil erosion load was simulated. A numerical statistical model was used to relate soil erosion to land use and landscape. The results indicated that decadal decrease of grassland areas did not pose a significant threat to soil erosion, while the continual increase of bare land, water area and farmland increased soil erosion. Regional landscape variation also had a strong relationship with erosion. Patch level landscape analyses demonstrated that larger water area led to more soil erosion. The patch correlation indicated that contagious grassland patches reduced soil erosion yield. The increased grassland patches led to more patch edges, in turn increasing the sediment transportation from the patch edges. The findings increase understanding of the temporal variation in soil erosion processes, which is the basis for preventing local pollution.

  3. Estimating potential wind erosion of agricultural lands in northern China using the Revised Wind Erosion Equation (RWEQ) and GIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fine materials emissions from severe wind-induced soil erosion have multiple impacts on land degradation and environmental pollution in the agro-pastoral ecotone in northern China (APEC). Assessment of wind erosion for the agricultural land management systems in APEC are needed to determine which sy...

  4. 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

  5. The use of straw to reduce the soil and water losses in agriculture and forest ecosystems in the Mediterranean Type-Ecosystem. The Soil Erosion and Degradation Research Group contribution

    NASA Astrophysics Data System (ADS)

    Cerda, Artemi; Burguet, Maria; Keesstra, Saskia; Borja, Manuel Esteban Lucas; Hedo, Javier; Brevik, Eric; Pereira, Paulo; Novara, Agata; Jordan, Antonio; Prosdocimi, Massimo; Taguas, Encarnacion

    2016-04-01

    Soil Erosion is a worldwide environmental issue (Keesstra et al., 2007; Dai et al., 2015; Erkossa et al., 2015; Ochoa-Cueva et al., 2015; Taguas et al., 2015). The high erosion rates are affecting mainly the non-developed countries due to the lack of vegetation cover, deforestation and the intense ploughing (Lieskovsky and Kenderessy, 2014; Biwas et al., 2015, Colazo and Buschiazzo, 2015; Ligonja and Shrestha, 2015); and the developing countries due to the herbicides abuse and heavy machinery (Cerdà et al., 2009; Novara et al., 2011). Non-sustainable erosion rates result in the loss of soil and also changes in the hydrological, erosional, biological, and geochemical cycles, which produce the lack of the services, goods and resources the soil offers to the humankind (Keesstra et al., 2012; Berendse et al., 2015; Decock et al., 2015; Brevik et al., 2015; Smith et al., 2015). This is why there is a need to reduce the soil losses, and to achieve a sustainable situation with lower and renewable soil erosion rates and to improve the infiltration rates (Cerdà et al., 2015; Nanko et al., 2015; Mwango et al., 2016). Vegetation cover is the most efficient strategy to control soil and water losses (Cerdà, 1999; Keesstra, 2007; Zhao et al., 2014), however there is the need to use other covers once the vegetation is not recovered such as after the forest fires or when the crops do not allow to have weeds and the soil should be bare. This is sometimes a cultural and aesthetic need (farmers from the Cànyoles river watershed personal comm). Under the above-mentioned circumstances, a straw cover can reduce the soil losses and increase infiltration. This is the main research topic that is being carried out by the Soil Erosion and Degradation Research Group from the University of Valencia during more than one decade: to find solutions to the non-sustainable soil erosion rates under forest and agriculture land under Mediterranean climatic conditions. The research was developed

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    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 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 clearly demonstrate the importance of root system architecture for the control of soil erosion. We also demonstrate that some plant species respond to nutrient enriched patches by increasing lateral root proliferation. The soil response to root proliferation will depend upon its location: at the soil surface dense mats of roots may block soil pores thereby limiting infiltration, enhancing runoff and thus erosion; whereas at depth local increases in shear strength may reinforce soils against structural failure at the shear plane. 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. Utilising nutrient placement at depth 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.

  7. 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.

  8. 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.

  9. A history of wind erosion prediction models in the United States Department of Agriculture: The Wind Erosion Prediction System (WEPS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of the Wind Erosion Prediction System (WEPS) was officially inaugurated in 1985 by United States Department of Agriculture-Agricultural Research Service (USDA-ARS) scientists in response to customer requests, particularly those coming from the USDA Soil Conservation Service (SCS), for im...

  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. 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

  12. Estimates of soil erosion using cesium-137 tracer models.

    PubMed

    Saç, M M; Uğur, A; Yener, G; Ozden, B

    2008-01-01

    The soil erosion was studied by 137Cs technique in Yatagan basin in Western Turkey, where there exist intensive agricultural activities. This region is subject to serious soil loss problems and yet there is not any erosion data towards soil management and control guidelines. During the soil survey studies, the soil profiles were examined carefully to select the reference points. The soil samples were collected from the slope facets in three different study areas (Kirtas, Peynirli and Kayisalan Hills). Three different models were applied for erosion rate calculations in undisturbed and cultivated sites. The profile distribution model (PDM) was used for undisturbed soils, while proportional model (PM) and simplified mass balance model (SMBM) were used for cultivated soils. The mean annual erosion rates found using PDM in undisturbed soils were 15 t ha(-1) year(-1) at the Peynirli Hill and 27 t ha(-1) year(-1) at the Kirtas Hill. With the PM and SMBM in cultivated soils at Kayişalan, the mean annual erosion rates were obtained to be 65 and 116 t ha(-1) year(-1), respectively. The results of 137Cs technique were compared with the results of the Universal Soil Loss Equation (USLE).

  13. 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.

  14. The use of straw to reduce the soil and water losses in agriculture and forest ecosystems in the Mediterranean Type-Ecosystem. The Soil Erosion and Degradation Research Group contribution

    NASA Astrophysics Data System (ADS)

    Cerda, Artemi; Burguet, Maria; Keesstra, Saskia; Borja, Manuel Esteban Lucas; Hedo, Javier; Brevik, Eric; Pereira, Paulo; Novara, Agata; Jordan, Antonio; Prosdocimi, Massimo; Taguas, Encarnacion

    2016-04-01

    Soil Erosion is a worldwide environmental issue (Keesstra et al., 2007; Dai et al., 2015; Erkossa et al., 2015; Ochoa-Cueva et al., 2015; Taguas et al., 2015). The high erosion rates are affecting mainly the non-developed countries due to the lack of vegetation cover, deforestation and the intense ploughing (Lieskovsky and Kenderessy, 2014; Biwas et al., 2015, Colazo and Buschiazzo, 2015; Ligonja and Shrestha, 2015); and the developing countries due to the herbicides abuse and heavy machinery (Cerdà et al., 2009; Novara et al., 2011). Non-sustainable erosion rates result in the loss of soil and also changes in the hydrological, erosional, biological, and geochemical cycles, which produce the lack of the services, goods and resources the soil offers to the humankind (Keesstra et al., 2012; Berendse et al., 2015; Decock et al., 2015; Brevik et al., 2015; Smith et al., 2015). This is why there is a need to reduce the soil losses, and to achieve a sustainable situation with lower and renewable soil erosion rates and to improve the infiltration rates (Cerdà et al., 2015; Nanko et al., 2015; Mwango et al., 2016). Vegetation cover is the most efficient strategy to control soil and water losses (Cerdà, 1999; Keesstra, 2007; Zhao et al., 2014), however there is the need to use other covers once the vegetation is not recovered such as after the forest fires or when the crops do not allow to have weeds and the soil should be bare. This is sometimes a cultural and aesthetic need (farmers from the Cànyoles river watershed personal comm). Under the above-mentioned circumstances, a straw cover can reduce the soil losses and increase infiltration. This is the main research topic that is being carried out by the Soil Erosion and Degradation Research Group from the University of Valencia during more than one decade: to find solutions to the non-sustainable soil erosion rates under forest and agriculture land under Mediterranean climatic conditions. The research was developed

  15. Comparative analyses of factors determining soil erosion rates based on network of Mediterranean monitored catchments for the innovative, adaptive and resilient agriculture of the future

    NASA Astrophysics Data System (ADS)

    Smetanová, Anna; Le Bissonnais, Yves; Raclot, Damien; Perdo Nunes, João; Licciardello, Feliciana; Mathys, Nicolle; Latron, Jérôme; Rodríguez Caballero, Emilio; Le Bouteiller, Caroline; Klotz, Sébastien; Mekki, Insaf; Gallart, Francesc; Solé Benet, Albert; Pérez Gallego, Nuria; Andrieux, Patrick; Jantzi, Hugo; Moussa, Roger; Planchon, Olivier; Marisa Santos, Juliana

    2015-04-01

    In order to project the soil erosion response to climate change in the fragile Mediterranean region it is inevitable to understand its existing patterns. Soil erosion monitoring on a catchment scale enables to analyse temporal and spatial variability of soil erosion and sediment delivery, while the integrating study of different catchments is often undertaken to depicther the general patterns. In this study, eight small catchments (with area up to 1,32 km2), representative for the western part of the Mediterranean region (according to climate, bedrock, soils and main type of land use) were compared. These catchments, grouped in the R-OS Med Network were situated in France (3), Spain (2), Portugal (1), Italy (1) and Tunisia (1). The average precipitation ranged between 236 to 1303 mm·a-1 and mean annual sediment yield varied 7.5 to 6900 Mg·km-2·a-1. The complex databes was based on more than 120 years of hydrological and sediment data, with series between 3 and 29 years long. The variability of sediment data was described on annual and monthly basis. The relationship between the sediment yield and more than 35 factors influencing the sediment yield including the characteristics of climate, topography, rainfall, runoff, land use, vegetation and soil cover, connectivity and dominant geomorphic processes, was studied. The preliminary results confirmed the differences in rainfall, runoff and sediment response, and revealed both the similarities and differences in soil erosion responses of the catchments. They are further dependent on the variability of factors themselves, with important contribution of the state of soil properties, vegetation cover and land use. Anna Smetanová has received the support of the European Union, in the framework of the Marie-Curie FP7 COFUND People Programme, through the award of an AgreenSkills' fellowship (under grant agreement n° 267196)

  16. 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.

  17. 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.

  18. Soil erosion in developing countries: A politicoeconomic explanation

    NASA Astrophysics Data System (ADS)

    Thapa, Gopal B.; Weber, Karl E.

    1991-07-01

    Soil erosion is accelerating in developing countries of Asia, Africa, and Latin America. It has threatened the livelihood of millions of peasants, for agriculture is their economic mainstay. A probe into the forces causing erosion reveals that the elite’s resolve to accumulate ever more wealth and to maintain, consolidate, or expand their sociopolitical power and the necessity of the poor to fulfill their requirements of food, fuelwood, and fodder are the two major factors accelerating soil erosion. Unless the vast masses of poor people are integrated into the national mainstream through the implementation of equitable and redistributive development policies, it is impossible to control the accelerating rate of soil erosion and thus to achieve the objective of sustainable development.

  19. Anthropogenic perturbation of the global carbon cycle as a result of agricultural carbon erosion and burial

    NASA Astrophysics Data System (ADS)

    Wang, Zhengang; Govers, Gerard; Kaplan, Jed; Hoffmann, Thomas; Doetterl, Sebastian; Six, Johan; Van Oost, Kristof

    2016-04-01

    Changes in terrestrial carbon storage exert a strong control over atmospheric CO2 concentrations but the underlying mechanisms are not fully constrained. Anthropogenic land cover change is considered to represent an important carbon loss mechanism, but current assessments do not consider the associated acceleration of carbon erosion and burial in sediments. We evaluated the role of anthropogenic soil erosion and the resulting carbon fluxes between land and atmosphere from the onset of agriculture to the present day. We show, here, that agricultural erosion induced a significant cumulative net uptake of 198±57 Pg carbon on terrestrial ecosystems. This erosion-induced soil carbon sink is estimated to have offset 74±21% of carbon emissions. Since 1850, erosion fluxes have increased 3-fold. As a result, the erosion and lateral transfer of organic carbon in relation to human activities is an important driver of the global carbon cycle at millennial timescales.

  20. 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.

  1. 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

  2. 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%.

  3. 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

  4. Spatial distribution of erosion and deposition on an agricultural watershed

    NASA Astrophysics Data System (ADS)

    Pineux, Nathalie; Gilles, Colinet; Degré, Aurore

    2013-04-01

    To better understand the agricultural landscapes evolution becomes an essential preoccupation and, for this, it is needed to take into account the sediments deposition, in a distributed way. As it is not possible in practice to study all terrestrial surfaces in detail by instrumenting sectors to obtain data, models of prediction are valuable tools to control the current problems, to predict the future tendencies and to provide a scientific base to the political decisions. In our case, a landscape evolution model is needed, which aims at representing both erosion and sedimentation and dynamically adjusts the landscape to erosion and deposition by modifying the initial digital elevation model. The Landsoil model (Landscape design for Soil conservation under soil use and climate change), among others, could fulfil this objective. It has the advantage to take the soil variability into account. This model, designed for the analysis of agricultural landscape, is suitable for simulations from parcel to catchment scale, is spatially distributed and event-based. Observed quantitative data are essential (notably to calibrate the model) but still limited. Particularly, we lack observations spatially distributed on the watershed. For this purpose, we choose a watershed in Belgium (Wallonia) which is a 124 ha agricultural zone in the loamy region. Its slopes range from 0% to 9%. To test the predictions of the model, comparisons will be done with: - sediment measurements which are done with water samplings in four points on the site to compare the net erosion results; - sediment selective measurements (depth variation observed along graduated bares placed on site) to compare the erosion and deposition results; - very accurate DSM's (6,76 cm pixel resolution X-Y) obtained by the drone (Gatewing X100) each winter. Besides planning what the landscape evolution should be, a revision of the soil map (drew in 1958) is organized to compare with the past situation and establish how the

  5. 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

  6. 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

  7. Erosion resistance of irrigated soils in the republic of Azerbaijan

    NASA Astrophysics Data System (ADS)

    Babaev, M. P.; Gurbanov, E. A.

    2010-12-01

    It was found that the average size of water-stable aggregates in irrigated soils varies in the range 0.23-2.0 mm, and the eroding flow velocity is 0.03-0.12 m/s. A five-point scale was used for assessing erosion resistance, predicting irrigation erosion, and developing erosion control measures on irrigated soils. According to this system, gray-brown soils and light sierozems were classified as the least erosion-resistant, sierozemic and meadow-sierozemic soils as low erosion-resistant, gray-cinnamonic soils as moderately erosion-resistant, mountain gray-cinnamonic soils as highly erosion-resistant, and steppe mountain cinnamonic soils as very highly erosion-resistant ones. The determination of the erosion resistance of soils is of great importance for assessing the erosion-resistance potential of irrigated areas and developing erosion control measures.

  8. 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...

  9. 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 ...

  10. 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)...

  11. 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.

  12. 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.

  13. 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 ...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. A method to detect soil carbon degradation during soil erosion

    NASA Astrophysics Data System (ADS)

    Alewell, Christine; Conen, Franz; Schaub, Monika

    2010-05-01

    Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs) approach (quantification of erosion rates) with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools) we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri). Transects from upland (erosion source) to wetland soils (erosion sinks) of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 4.6 tha-1 yr-1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 500-600 and 350-400 years of erosion input into the wetlands Laui and Spissen, respectively. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

  20. A method to detect soil carbon degradation during soil erosion

    NASA Astrophysics Data System (ADS)

    Alewell, C.; Schaub, M.; Conen, F.

    2009-06-01

    Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs) approach (quantification of erosion rates) with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools) we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri). Transects from upland (erosion source) to wetland soils (erosion sinks) of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 2.6 t ha-1 yr-1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 800 and 400 years of erosion input into the wetlands. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

  1. A method to detect soil carbon degradation during soil erosion

    NASA Astrophysics Data System (ADS)

    Alewell, C.; Schaub, M.; Conen, F.

    2009-11-01

    Soil erosion has been discussed intensively but controversial both as a significant source or a significant sink of atmospheric carbon possibly explaining the gap in the global carbon budget. One of the major points of discussion has been whether or not carbon is degraded and mineralized to CO2 during detachment, transport and deposition of soil material. By combining the caesium-137 (137Cs) approach (quantification of erosion rates) with stable carbon isotope signatures (process indicator of mixing versus degradation of carbon pools) we were able to show that degradation of carbon occurs during soil erosion processes at the investigated mountain grasslands in the central Swiss Alps (Urseren Valley, Canton Uri). Transects from upland (erosion source) to wetland soils (erosion sinks) of sites affected by sheet and land slide erosion were sampled. Analysis of 137Cs yielded an input of 2 and 4.6 tha-1 yr-1 of soil material into the wetlands sites. Assuming no degradation of soil organic carbon during detachment and transport, carbon isotope signature of soil organic carbon in the wetlands could only be explained with an assumed 500-600 and 350-400 years of erosion input into the wetlands Laui and Spissen, respectively. The latter is highly unlikely with alpine peat growth rates indicating that the upper horizons might have an age between 7 and 200 years. While we do not conclude from our data that eroded soil organic carbon is generally degraded during detachment and transport, we propose this method to gain more information on process dynamics during soil erosion from oxic upland to anoxic wetland soils, sediments or water bodies.

  2. 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...

  3. Scale linkage and contingency effects of field-scale and hillslope-scale controls of long-term soil erosion: Anthropogeomorphic sediment flux in agricultural loess watersheds of Southern Germany

    NASA Astrophysics Data System (ADS)

    Houben, Peter

    2008-10-01

    Agricultural landscapes with a millennial-scale history of cultivation are common in many loess areas of central Europe. Over time, patterns of erosion and sedimentation have been continually modified via the variable imposition of anthropogenic discontinuities and linkages on fragmented hillslope sediment cascades, which eventually caused the complicated soilscape pattern. These field records challenge topographically oriented models of hillslope erosion and simple predictions of longer-term change of spatial soilscape by cultivation activities. A thorough understanding how soilscape patterns form in the long-term, however, is essential to develop spatial concepts of the sediment budget, particularly for the spatial modeling of anthropogenic hillslope sediment flux using GIS. In this study I used extensive datasets of anthropogenic soil truncation and burial in a typical undulating loess watershed in southern Germany (10 km 2, Wetterau Basin, N of Frankfurt a.M.). Spatial soilscape properties and historic sediment flux, as caused by cultivation over seven millennia, were evaluated by these data. The soilscape pattern on the low-gradient hillslopes of the study area was found to be marked by a statistical near-random pattern of varying depth (thickness) of truncation and overthickened burial. Moreover, it was shown that truncation and burial had developed independently from each other and did not correlate with either hillslope gradient or downslope curvature. Hence, in the field any combination of (few) nearly preserved, severely truncated or completely removed soil profiles with either no, some or a thick sediment cover is present, thereby lacking an obvious spatial pattern. Here, I suggest putting long-term change of the soilscape into a contextual anthropogeomorphic systems perspective, that accommodates components of human-induced soil erosion operating at different spatial scales to interpret the longer-term spatial consequences at the hillslope-system level

  4. The use of caesium-137 to estimate agricultural erosion on steep slopes in a tropical watershed

    NASA Astrophysics Data System (ADS)

    Nagle, Gregory N.; Lassoie, James P.; Fahey, Timothy J.; McIntyre, Sherwood C.

    2000-04-01

    The estimation of erosion and sediment delivery rates in tropical mountain watersheds is difficult and most of the methods widely used for estimating soil erosion over large areas have serious limitations. The 137Cs approach has potential for quantifying soil erosion because it can provide retrospective estimates of long-term (since 1963) net sediment redistribution relatively quickly. Despite its great potential, 137Cs has not yet been used in an extensive, reconnaissance level survey of erosion in complex tropical mountain environments. The objective of this study was to examine the applicability of the 137Cs method to estimate erosion on steep tropical agricultural lands (23 to 80% slopes) in the Nizao watershed, a humid, tropical mountain area of the Dominican Republic. In this study we (i) examine the variation of 137Cs in ten reference sites - eight coffee groves and two forested sites - and (ii) estimate erosion from 14 cultivated fields.The soil pool of 137Cs ranged from to 150 to 192 mBq cm-2 on reference sites with minimal erosion. Variability among reference sites was less than expected for such complex mountain terrain. The variability within coffee and forested reference (average CV=28%) sites was similar to the variability found on grassland and forested reference sites in the temperate zone.The estimated annual soil loss from 14 sampled fields ranged from 6 to 61 t ha-1 year-1 with an overall mean of 26 t ha-1 year-1. Overall, the soil erosion estimates found using the erosion estimates account for soil loss since 1963 only and it seems likely that soil losses may have been much higher in earlier decades immediately after initial forest clearing earlier in the 20th century.

  5. 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

  6. Nitrogen loss from windblown agricultural soils in the Columbia Plateau

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion of agricultural soils can degrade both air quality and soil productivity in the Columbia Plateau of the Pacific Northwest United States. Soils in the region contain fine particles that, when suspended, are highly susceptible to long range transport in the atmosphere. Nitrogen (N) associ...

  7. 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.

  8. Comparing erosion rates in burnt forests and agricultural fields for a mountain catchment in NW Iberia

    NASA Astrophysics Data System (ADS)

    Nunes, João Pedro; Marisa Santos, Juliana; Bernard-Jannin, Léonard; Keizer, Jan Jacob

    2013-04-01

    A large part of northwestern Iberia is nowadays covered by commercial forest plantations of eucalypts and maritime pines, which have partly replaced traditional agricultural land-uses. The humid Mediterranean climate, with mild wet winters and warm dry summers, creates favorable conditions for the occurrence of frequent and recurrent forest fires. Erosion rates in recently burnt areas have been the subject of numerous studies; however, there is still a lack of information on their relevance when compared with agricultural erosion rates, impairing a comprehensive assessment of the role of forests for soil protection. This study focuses on Macieira de Alcoba, head-water catchment in the Caramulo Mountain Range, north-central Portugal, with a mixture of agricultural fields (mostly a rotation between winter pastures and summer cereals) on the lower slopes and forest plantations (mostly eucalypts) on the upper slopes. Agricultural erosion in this catchment has been monitored since 2010; a forest fire in 2011 presented an opportunity to compare post-fire and agricultural erosion rates at nearby sites with comparable soil and climatic conditions. Erosion rates were monitored between 2010 and 2013 by repeated surveys of visible erosion features and, in particular, by mapping and measuring rills and gullies after important rainfall events. During the 2011/2012 hydrological year, erosion rates in the burnt forest were two orders of magnitude above those in agricultural fields, amounting to 17.6 and. 0.1 Mg ha-1, respectively. Rills were widespread in the burnt area, while in the agricultural area they were limited to a small number of fields with higher slope; these particular fields experienced an erosion rate of 2.3 Mg ha-1, still one order of magnitude lower than at the burnt forest site. The timing of the erosion features was also quite distinct for the burnt area and the agricultural fields. During the first nine months after the fire, rill formation was not observed in

  9. 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

  10. Forests and Soil Erosion across Europe

    NASA Astrophysics Data System (ADS)

    Bathurst, J. C.

    2012-04-01

    Land use and climate change threaten the ability of Europe's forests to provide a vital service in limiting soil erosion, e.g. from forest fires and landslides. However, our ability to define the threat and to propose mitigation measures suffers from two deficiencies concerning the forest/erosion interface: 1) While there have been a considerable number of field studies of the relationship between forest cover and erosion in different parts of Europe, the data sets are scattered among research groups and a range of literature outlets. There is no comprehensive overview of the forest/erosion interface at the European scale, essential for considering regional variations and investigating the effects of future changes in land use and climate. 2) Compared with forest/water studies, we have a poorer quantitative appreciation of forest/erosion interactions. In the forest/water area it is possible to make quantitative statements such as that a 20% change in forest cover across a river catchment is needed for the effect on annual water yield to be measurable or that a forested catchment in upland UK has an annual water yield around 15% lower than an otherwise comparable grassland catchment. Comparable statements are not yet possible for forest/erosion interactions and there are uncertainties in the mathematical representation of forest/erosion interactions which limit our ability to make predictions, for example of the impact of forest loss in a given area. This presentation therefore considers the next step in improving our predictive capability. It proposes the integration of existing research and data to construct the "big picture" across Europe, i.e. erosion rates and sediment yields associated with forest cover and its loss in a range of erosion regimes (e.g. post-forest fire erosion or post-logging landslides). This would provide a basis for generalizations at the European scale. However, such an overview would not form a predictive capability. Therefore it is also

  11. 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

  12. 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.

  13. 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…

  14. 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

  15. 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.

  16. 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

    tolerable soil erosion rate, the soil erosion management will be applied base on cost and benefit analysis. The soil erosion management measures will conduct as decision maker of defining the best alternative soil conservation method in a certain area. Besides the engineering and theoretical methods, the local wisdom also will be taken into account in defining the alternative manners of soil erosion management. As a prototype, this integrated model will be generated and simulated in Serayu Watershed, Central Java, since this area has a serious issue in soil erosion problem mainly in the upper stream area (Dieng area). The extraordinary monoculture plantation (potatoes) and very intensive soil tillage without proper soil conservation method has accelerated the soil erosion and depleted the soil fertility. Based on the potatoes productivity data (kg/ha) from 1997-2007 showed that there was a declining trend line, approximately minus 8,2% every year. On the other hand the fertilizer and pesticide consumption in agricultural land are significantly increasing every year. In the same time, the high erosion rate causes serious sedimentation problem in lower stream. Those conditions can be used as study case in determining the element at risk of soil erosion and calculation method for the total soil erosion cost (on-site and off-site effect). Moreover, The Serayu Watershed consists of complex landforms which might have variation of soil erosion tolerable rate. In the future, this integrated model can obtain valuable basis data of the soil erosion hazard in spatial and temporal information including its total cost, the sustainability time of certain land or agriculture area, also the consequences price of applying certain agriculture or soil management. Since this model give result explicitly in spatial and temporal, this model can be used by the local authority to run the land use scenario in term of soil erosion impact before applied them in the real condition. In practice, such

  17. 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.

  18. 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).

  19. 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.

  20. 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

  1. 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

  2. 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 ...

  3. 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...

  4. Diachronical soil surveys: a way to quantify long term diffuse erosion

    NASA Astrophysics Data System (ADS)

    Pineux, Nathalie; Brieuc, Michel; Xavier, Legrain; Gilles, Colinet; Aurore, Degré

    2015-04-01

    The loess belt of Western Europe is a high-risk area regarding diffuse erosion. It is due to the climate and the topography but also to the soil type. Loamy soils are naturally highly sensitive to diffuse erosion. Hence, these soils are very fertile. So, they are intensively cultivated which increases their sensitivity to erosion. Sheet erosion is an erosion type strongly represented in these regions. Contrarily to the concentrated form of erosion which happens more brutally, sheet erosion needs long-term observation time-scales, which remains rare. In Belgium, a soil map was established in 1956. This map is quite detailed and notably informs about the different horizons which are in the profile (ploughed horizon, eluvial horizon, clay included between the horizons, carbonate-free loess horizon, and all these were characterised by drainage class) and their depth. It was based on a dense augering network across the country (one point every 75 meters). A new augering campaign was done again in 2014. It consisted in one observation every 50 meters on an agricultural watershed of 124 hectares located in the centre of Belgium. This catchment has been cultivated since the 14th century and is representative of the local context (gentle slope (3-8%), plot size (mean value of 10 ha), …). We compared the two soil maps produced on this site with a 58years time lapse. Results show that the large majority of the watershed falls from upslope soils with weak erosion to slope soils with strong erosion. The soil thickness diminished in some zones to 1m10 (minimum estimation) of erosion. This comparison shows that very few upslope soils are preserved. On the other hand, the areas where colluviums were present to the full depth stay at the same place in the main thalweg of the watershed. Other areas on the watershed seem to be subject to a (minimum estimation) of 40cm of sediments deposition. Large areas in the watershed suffered from erosion and came to deposition areas as the

  5. 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.

  6. Short-term changes in upland soil erosion in England and Wales: 1999 to 2002

    NASA Astrophysics Data System (ADS)

    McHugh, Marianne

    2007-04-01

    Erosion was assessed on upland sites between October 2001 and June 2002, and compared with measurements of erosion made at the same sites during previous visits (1999). In addition to highlighting the scale of changes in erosion extent and nature over the sample period, the data were used to determine the influence of field site management and weather conditions on upland erosion. Results indicated that site erosion continued over the duration of the study, with most upland regions of England and Wales experiencing increases in erosion area and volume. On 52% of the 139 sites surveyed, increases in erosion extent resulted in 705 m 2 of newly exposed soil. Sheep were identified as the most frequent cause of this increased erosion, although the impacts of humans (through vehicle access, footpaths and drainage) were also extensive. Water-driven erosion processes were also prevalent in the maintenance of bare soil, both alone and in combination with other factors such as sheep, walkers and general weather conditions. Revegetation of bare soil was also an important feature of upland sites, resulting in a net decrease in erosion area on 63% of sites. The implications of these changes in erosion are discussed in the light of continuing changes in land use and management in the UK uplands, particularly those of reform of the EU Common Agricultural Policy (CAP), and in view of predicted changes in climate.

  7. Soil moisture: Some fundamentals. [agriculture - soil mechanics

    NASA Technical Reports Server (NTRS)

    Milstead, B. W.

    1975-01-01

    A brief tutorial on soil moisture, as it applies to agriculture, is presented. Information was taken from books and papers considered freshman college level material, and is an attempt to briefly present the basic concept of soil moisture and a minimal understanding of how water interacts with soil.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Shrublands and Soil Erosion. An State-of-the-Art Arid and semiarid regions occupy two-fifth of the continents (Reynolds et al., 2007). These regions are characterized by dry climatic conditions, recurrent droughts and a scant rainfall pattern with a marked seasonality and a high inter-annual variability which makes water to be a scant resource and vegetation to follow a high variability spatial distribution pattern (Breshears et al., 1998; Cecchi et al., 2006; Dunkerley, 2008). These conditions make these areas more sensitive to climate change (Rowell, 2005) and to land use change as a consequence of land abandonment (Poyatos et al., 2003; Delgado et al., 2010; García-Ruiz, 2010), increasing the risk of desertification (Puigdefábregas and Mendizabal, 1998; Geeson et al., 2002), in such a way that 65-70% of arid and semiarid areas are vulnerable to this degradation process (UNEP, 1991). Soil Erosion and Land Degradation are closely related to the changes in the vegetation cover (Zhao et al., 2013). Although other factors such as rainfall intensity or slope (Ziadat and Taimeh, 2013) the plant cover is the main factor that controls the soil erosion, controlling the infiltration and runoff generation (Cerdà, 1998a; Kargar Chigani et al., 2012; Haregeweyn, 2013). Soil erosion show non-sustainable rates under these regions, such as under Mediterranean conditions (Cerdà et al., 2010) and on agriculture land (Cerdà et al; 2007; 2009) due to climatic conditions, to parent material and to the roughed terrain (Romero Díaz et al., 2010). The traditional impact of grazing, of extremely intense fires, of ploughing and the widespread use of herbicides on agriculture, the increase of the road and railway embankments and the agricultural land abandonment cause vegetation removal. Canopy cover partitions rainfall reducing the amount of water reaching the soil and the kinetic energy of rainfall drops, protecting the soil against the impact of rainfall drops. Vegetation

  9. 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.

  10. Degradation of soil physicochemical quality by ephemeral gully erosion on sloping cropland of the hilly Loess Plateau, China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ephemeral gully erosion (EGE) is a common type of shallow linear erosion that exerts a major threat to the productivity and sustainability of agricultural systems. The objective was to evaluate the impact of EGE on soil physicochemical properties that determine soil quality. It was hypothesized that...

  11. Impact of Climate Change on Inland Northwest Soil Erosion Under Various Land Management Practices

    NASA Astrophysics Data System (ADS)

    Farrell, P.; Abatzoglou, J. T.; Brooks, E. S.

    2014-12-01

    Changes in climate are hypothesized to have a multitude of impacts on the agricultural productivity of the inland Northwest of the United States. Much of the agricultural land in the region is composed of winter wheat and is managed under various tilling practices. Soil erosion under these various tilling practices and climate could be detrimental to the agricultural economy of the region and food security. We explore the susceptibility of the agricultural land of the region to erosion impacts under future climate scenarios using a two-pronged approach using the Water Erosion Prediction Project (WEPP) model. First, we assess the sensitivity of soil erosion to changes in climate variables including precipitation, temperature and precipitation intensity. This sensitivity analysis is done across several geographic regions, different hill slopes, soil types and land management practices. Secondly, we use downscaled climate projections from 20 climate models for the mid-21st century to develop probabilistic estimates of changes in soil erosion across the region. These projected changes are further contextualized using the sensitivity experiments. Finally, we examine whether changes in erosion due to climate change may be partially offset by changes in land management.

  12. 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...

  13. 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.

  14. 10-daily soil erosion modelling over sub-Saharan Africa.

    PubMed

    Symeonakis, Elias; Drake, Nick

    2010-02-01

    Soil erosion is considered to be one of the greatest environmental problems of sub-Saharan Africa. This paper investigates the advantages and disadvantages of modelling soil erosion at the continental scale and suggests an operational methodology for mapping and quantifying 10-daily water runoff and soil erosion over this scale using remote sensing data in a geographical information system framework. An attempt is made to compare the estimates of this study with general data on the severity of soil erosion over Africa and with measured rates of soil loss at different locations over the continent. The results show that the measured and estimated rates of erosion are in some areas very similar and in general within the same order of magnitude. The importance and the potential of using the soil erosion estimates with simple models and easily accessible free data for various continental-scale environmental applications are also demonstrated.

  15. 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...

  16. 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.

  17. 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).

  18. 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.

  19. 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

  20. 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

  1. 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 RUSLE2015

  2. 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...

  3. Making Other Worlds: Modelling Past Interactions of Agriculture and Erosion

    NASA Astrophysics Data System (ADS)

    Wainwright, J.

    2012-04-01

    It is argued that the understanding of past agricultural erosion has been greatly simplified because conceptual or numerical models have been used that emphasize the technical aspects of the erosion process, fail to recognize the spatial and temporal scaling of the erosion, and especially ignore the idea that such erosion is the result of multiple, interacting decisions made by people. While there have been significant developments in the first two of these areas over the last decade, there has been little explicit recognition of the third of these limitations. This problem is a consequence of the very different disciplinary approaches that are needed. One method that can be used to address this limitation is that of agent-based modelling. Agent-based models permit an explicit representation of how individuals or groups of individuals interact with each other and their environment. Furthermore, environmental changes can be fed back into agent behaviour, and other potential controls such as climate variations can be assessed. The CYBEROSION modelling framework has been developed to take this approach and evaluate patterns of erosion due to past land-use decision-making. Examples will be drawn from case studies in the Neolithic and Bronze Age, largely from the Mediterranean region. The emphasis is on modelling as a heuristic approach to understanding, rather than necessarily as a predictive tool. In particular, it provides guidance in relation to which parts of existing discipline-bound knowledge are needed to produce an explicit, interdisciplinary understanding of patterns of landscape change as a result of changing agricultural practice. Results from the case studies demonstrate how complex spatio-temporal patterns of past erosion can arise from relatively simple, local interactions between people and their environment. To conclude, will also be an assessment of more modern examples, as well as of related literature in archaeology, and geoarchaeology, and a

  4. Modeling biogeochemistry in agricultural soils

    SciTech Connect

    Li, C.; Frolking, S.; Harriss, R.

    1994-09-01

    An existing model of C and N dynamics in soils was supplemented with a plant growth submodel and cropping practice routines (fertilization, irrigation, tillage, crop rotation, and manure amendments) to study the biogeochemistry of soil carbon in arable lands. The new model was validated against field results for short-term (1-9 years) decomposition experiments, the seasonal pattern of soil CO{sub 2} respiration, and long-term (100 years) soil carbon storage dynamics. A series of sensitivity runs investigated the impact of varying agricultural practices on soil organic carbon (SOC) sequestration. The tests were simulated for corn (maize) plots over a range of soil and climate conditions typical of the United States. The largest carbon sequestration occurred with manure additions; the results were very sensitive to soil texture (more clay led to greater sequestration). Increased N fertilization generally enhanced carbon sequestration, but the results were sensitive to soil texture, initial soil carbon content, and annual precipitation. Reduced tillage also generally (but not always) increased SOC content, through the results were very sensitive to soil texture, initial SOC content, and annual precipitation. A series of long-term simulations investigated the SOC equilibrium for various agricultural practices, soil and climate conditions, and crop rotations. Equilibrium SOC content increased with decreasing temperatures, increasing clay content, enhanced N fertilization, manure amendments, and crops with higher residue yield. Time to equilibrium appears to be one hundred to several hundred years. In all cases, equilibration time was longer for increasing SOC content than for decreasing SOC content. Efforts to enhance carbon sequestration in agricultural soils would do well to focus on those specific areas and agricultural practices with the greatest potential for increasing soil carbon content. 64 refs., 13 figs., 5 tabs.

  5. 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

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Shrublands and Soil Erosion. An State-of-the-Art Arid and semiarid regions occupy two-fifth of the continents (Reynolds et al., 2007). These regions are characterized by dry climatic conditions, recurrent droughts and a scant rainfall pattern with a marked seasonality and a high inter-annual variability which makes water to be a scant resource and vegetation to follow a high variability spatial distribution pattern (Breshears et al., 1998; Cecchi et al., 2006; Dunkerley, 2008). These conditions make these areas more sensitive to climate change (Rowell, 2005) and to land use change as a consequence of land abandonment (Poyatos et al., 2003; Delgado et al., 2010; García-Ruiz, 2010), increasing the risk of desertification (Puigdefábregas and Mendizabal, 1998; Geeson et al., 2002), in such a way that 65-70% of arid and semiarid areas are vulnerable to this degradation process (UNEP, 1991). Soil Erosion and Land Degradation are closely related to the changes in the vegetation cover (Zhao et al., 2013). Although other factors such as rainfall intensity or slope (Ziadat and Taimeh, 2013) the plant cover is the main factor that controls the soil erosion, controlling the infiltration and runoff generation (Cerdà, 1998a; Kargar Chigani et al., 2012; Haregeweyn, 2013). Soil erosion show non-sustainable rates under these regions, such as under Mediterranean conditions (Cerdà et al., 2010) and on agriculture land (Cerdà et al; 2007; 2009) due to climatic conditions, to parent material and to the roughed terrain (Romero Díaz et al., 2010). The traditional impact of grazing, of extremely intense fires, of ploughing and the widespread use of herbicides on agriculture, the increase of the road and railway embankments and the agricultural land abandonment cause vegetation removal. Canopy cover partitions rainfall reducing the amount of water reaching the soil and the kinetic energy of rainfall drops, protecting the soil against the impact of rainfall drops. Vegetation

  7. Assessment of soil erosion under woodlands using USLE in China

    NASA Astrophysics Data System (ADS)

    Zhang, Changshun; Xie, Gaodi; Liu, Chunlan; Lu, Chunxia

    2011-06-01

    Universal Soil Loss Equation (USLE), originally developed by the USDA for agricultural lands and then used throughout the world, was applied in mountainous forest terrain in China. The woodland area was divide into 100 m × 100 m grid cells. The ArcInfo 9.2 GIS software provided spatial input data was used to predict the spatial distribution of the average annual soil loss on grid basis. The average rainfall erositivity factor ( R) for national woodlands was found to be 21-1798 MJ·mm·ha-1·h-1·a-1. The soil erodibility factor ( K) with a magnitude of 0.043 t·ha·h· ha-1·MJ-1·mm-1 is the highest for Chinese woodland. Most of the slope length factors ( LS) were less than 5 for the national woodland. The highest and lowest values of cover and management factor ( C) were found out to be 0.0068 and 0.2550 respectively for coniferous woodland and orchard woodland. The value of conservation factor ( P) was assigned to be 1 for Chinese woodlands because of scarcity of conversation practice data at the national scale. The average annual soil loss of the national woodland areas was 3.82 t·km-2·a-1. About 99.89% of Chinese woodland area was found out to be under slight erosion class, whereas it only resulted in about 41.97% of soil loss under woodland area, and 58.03% of soil loss occurred under high erosion potential zone, namely more than 5 t·ha-1·a-1. Therefore, those zones need immediate attention from soil conservation point of view. The results here are consistent with many domestic and oversea previous researches under mountainous forests or hilly catchments, thus we showed that the USLE can be applied to estimations of soil erosion for Chinese woodlands at the national scale.

  8. 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

  9. 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…

  10. Moderate topsoil erosion rates constrain the magnitude of the erosion-induced carbon sink and agricultural productivity losses on the Chinese Loess Plateau

    NASA Astrophysics Data System (ADS)

    Zhao, Jianlin; Van Oost, Kristof; Chen, Longqian; Govers, Gerard

    2016-08-01

    Despite a multitude of studies, overall erosion rates as well as the contribution of different erosion processes on Chinese Loess Plateau (CLP) remain uncertain, which hampers a correct assessment of the impact of soil erosion on carbon and nutrient cycling as well as on crop productivity. In this paper we used a novel approach, based on field evidence, to reassess erosion rates on the CLP before and after conservation measures were implemented (1950 vs. 2005). We found that current average topsoil erosion rates are 3 to 9 times lower than earlier estimates suggested. Under 2005 conditions, more sediment was produced by non-topsoil erosion (gully erosion (0.23 ± 0.28 Gt yr-1) and landsliding (0.28 ± 0.23 Gt yr-1) combined) than by topsoil erosion (ca. 0.30 ± 0.08 Gt yr-1). Overall, these erosion processes mobilized ca. 4.77 ± 1.96 Tg yr-1 of soil organic carbon (SOC): the latter number sets the maximum magnitude of the erosion-induced carbon sink, which is ca. 4 times lower than one other recent estimate suggests. The programs implemented from the 1950s onwards reduced topsoil erosion from 0.51 ± 0.13 to 0.30 ± 0.08 Gt yr-1 while SOC mobilization was reduced from 7.63 ± 3.52 to 4.77 ± 1.96 Tg C yr-1. Conservation efforts and reservoir construction have disrupted the equilibrium that previously existed between sediment and SOC mobilization on the one hand and sediment and SOC export to the Bohai sea on the other hand: nowadays, most eroded sediments and carbon are stored on land. Despite the fact that average topsoil losses on the CLP are still relatively high, a major increase in agricultural productivity has occurred since 1980. Fertilizer application rates nowadays more than compensate for the nutrient losses by (topsoil) erosion: this was likely not the case before the dramatic rise of fertilizer use that started around 1980. Hence, erosion is currently not a direct threat to agricultural productivity on the CLP but the long-term effects of erosion on

  11. 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

  12. Soil formation in response to perturbed erosion rates

    NASA Astrophysics Data System (ADS)

    Mudd, Simon; Milodowski, David; Yoo, Kyungsoo; Gabet, Emmanuel; Weinman, Beth; Attal, Mikael; Clubb, Fiona

    2014-05-01

    Time is recognized as one of the soil forming factors. In upland, sloping landscapes time is controlled by erosion rates. These erosion rates may be forced by climate, tectonics, and increasingly anthropogenic disturbance. Perturbations to erosion rates alter the exposure of near surface material to both physical and chemical weathering, which can influence water retention, plant growth and sediment transport. All of these can feed back into further perturbation of erosion rates. Here we present field data, topographic analysis and numerical modelling from a field site in the Sierra Nevada of California where we have attempted to examine soil formation across a range of erosion rates, and determine their influence on soil particle size, geochemistry and plant life, as well as the geomorphic signature of overland flow. Erosion rates have strong impact on soils, leading to coarser soils that support less biomass when erosion rates are high and clay rich soils with higher biomass when erosion rates are low. Erosion rates also appear to influence the dissection of the landscape by channels, which we quantify using high resolution topographic analysis.

  13. Soil erosion in developing countries: a socio-economic appraisal.

    PubMed

    Ananda, Jayanath; Herath, Gamini

    2003-08-01

    Soil erosion is the single most important environmental degradation problem in the developing world. Despite the plethora of literature that exists on the incidence, causes and impacts of soil erosion, a concrete understanding of this complex problem is lacking. This paper examines the soil erosion problem in developing countries in order to understand the complex inter-relationships between population pressure, poverty and environmental-institutional dynamics. Two recent theoretical developments, namely Boserup's theory on population pressure, poverty and soil erosion and Lopez's theory on environmental and institutional dynamics have been reviewed. The analysis reveals that negative impacts of technical change, inappropriate government policies and poor institutions are largely responsible for the continued soil erosion in developing countries. On the other hand, potential for market-based approaches to mitigate the problem is also low due to the negative externalities involved. A deeper appreciation of institutional and environmental dynamics and policy reforms to strengthen weak institutions may help mitigate the problem.

  14. Mapping Soil Erosion Factors and Potential Erosion Risk for the National Park "Central Balkan"

    NASA Astrophysics Data System (ADS)

    Ilieva, Diliana; Malinov, Ilia

    2014-05-01

    Soil erosion is widely recognised environmental problem. The report aims at presenting the main results from assessment and mapping of the factors of sheet water erosion and the potential erosion risk on the territory of National Park "Central Balkan". For this purpose, the Universal Soil Loss Equation (USLE) was used for predicting soil loss from erosion. The influence of topography (LS-factor) and soil erodibility (K-factor) was assessed using small-scale topographic and soil maps. Rainfall erosivity (R-factor) was calculated from data of rainfalls with amounts exceeding 9.5 mm from 14 hydro-meteorological stations. The values of the erosion factors (R, K and LS) were presented for the areas of forest, sub-alpine and alpine zones. Using the methods of GIS, maps were plotted presenting the area distribution among the classes of the soil erosion factors and the potential risk in the respective zones. The results can be used for making accurate decisions for soil conservation and sustainable land management in the park.

  15. 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.

  16. 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.

  17. 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

  18. Geomorphic Controls of Soil and Carbon Redistribution Across an Agricultural Landscape

    NASA Astrophysics Data System (ADS)

    Ritchie, J. C.; McCarty, G. W.; Venteris, E. R.; Kaspar, T. C.

    2006-12-01

    Patterns of soil organic carbon (SOC) vary widely across the landscape leading to large uncertainties in the SOC budget especially for agricultural landscapes where water, tillage, and wind erosion redistributes soil and SOC. It is often assumed that soil erosion results in a loss of SOC from the agricultural ecosystem but recent studies indicate that soil erosion and its subsequent redistribution within fields can stimulate SOC sequestration in agricultural fields. This study investigates the relationship between soil and SOC redistribution patterns in relationship to geomorphic position in two tilled agricultural fields using the fallout Cesium-137 technique to measure soil redistribution. Cesium-137 and SOC concentrations in agricultural soils are significantly correlated in our study areas. Hillslope areas (eroding) have significantly less SOC than soils in toe slope areas (deposition). SOC decreased as gradient slope increases and soils on concave slopes had higher SOC than soils on convex slopes. These data suggest that soil redistribution patterns and topographic patterns may be used to help understand SOC dynamics on agricultural landscapes. Different productivity and oxidation rates of SOC of eroded versus deposited soils also contribute to SOC spatial patterns. However, the strong significant relationships between the patterns of soil redistribution and SOC concentrations in agricultural soils suggest that they are moving along similar physical pathways in these systems. Our study also indicates that geomorphic position is important for understanding soil and SOC movement and redistribution patterns within a field or watershed. Such information can help develop and implement management systems to increase SOC in agricultural ecosystems.

  19. Reassessment of soil erosion on the Chinese loess plateau: were rates overestimated?

    NASA Astrophysics Data System (ADS)

    Zhao, Jianlin; Govers, Gerard

    2014-05-01

    in significantly higher erodibility values than those obtained from field data. Overestimations of the P and LS factors are mainly due to the fact that erosion control measures such as terracing are not accounted for and that erroneous scaling functions are used on permanently vegetated areas. Our findings have not only important implications with respect to the mobilization of sediments by agricultural erosion: we will also need to reassess the impact of erosion on biogeochemicaly cycling and crop productivity. Fu, B., Liu, Y., Lü, Y., He, C., Zeng, Y., & Wu, B. (2011). Assessing the soil erosion control service of ecosystems change in the Loess Plateau of China. Ecological Complexity, 8(4), 284-293. doi:10.1016/j.ecocom.2011.07.003 Nearing, M. A. (1997). A single, continuous function for slope steepness influence on soil loss. Soil Science Society of American Journal, 61(3), 917-919. Quinton, J. N., Govers, G., Van Oost, K., & Bardgett, R. D. (2010). The impact of agricultural soil erosion on biogeochemical cycling. Nature Geoscience, 3(5), 311-314. doi:10.1038/ngeo838 Sun, W., Shao, Q., & Liu, J. (2013). Soil erosion and its response to the changes of precipitation and vegetation cover on the Loess Plateau. Journal of Geographical Sciences, 23(6), 1091-1106. doi:10.1007/s11442-013-1065-z

  20. 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.

  1. 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.

  2. Use of USLE/GIS methodology for predicting soil loss in a semiarid agricultural watershed.

    PubMed

    Erdogan, Emrah H; Erpul, Günay; Bayramin, Ilhami

    2007-08-01

    The Universal Soil Loss Equation (USLE) is an erosion model to estimate average soil loss that would generally result from splash, sheet, and rill erosion from agricultural plots. Recently, use of USLE has been extended as a useful tool predicting soil losses and planning control practices in agricultural watersheds by the effective integration of the GIS-based procedures to estimate the factor values in a grid cell basis. This study was performed in the Kazan Watershed located in the central Anatolia, Turkey, to predict soil erosion risk by the USLE/GIS methodology for planning conservation measures in the site. Rain erosivity (R), soil erodibility (K), and cover management factor (C) values of the model were calculated from erosivity map, soil map, and land use map of Turkey, respectively. R values were site-specifically corrected using DEM and climatic data. The topographical and hydrological effects on the soil loss were characterized by LS factor evaluated by the flow accumulation tool using DEM and watershed delineation techniques. From resulting soil loss map of the watershed, the magnitude of the soil erosion was estimated in terms of the different soil units and land uses and the most erosion-prone areas where irreversible soil losses occurred were reasonably located in the Kazan watershed. This could be very useful for deciding restoration practices to control the soil erosion of the sites to be severely influenced.

  3. 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

  4. Multi-temporal Soil Erosion Modelling over the Mt Kenya Region with Multi-Sensor Earth Observation Data

    NASA Astrophysics Data System (ADS)

    Symeonakis, Elias; Higginbottom, Thomas

    2015-04-01

    Accelerated soil erosion is the principal cause of soil degradation across the world. In Africa, it is seen as a serious problem creating negative impacts on agricultural production, infrastructure and water quality. Regarding the Mt Kenya region, specifically, soil erosion is a serious threat mainly due to unplanned and unsustainable practices linked to tourism, agriculture and rapid population growth. The soil types roughly correspond with different altitudinal zones and are generally very fertile due to their volcanic origin. Some of them have been created by eroding glaciers while others are due to millions of years of fluvial erosion. The soils on the mountain are easily eroded once exposed: when vegetation is removed, the soil quickly erodes down to bedrock by either animals or humans, as tourists erode paths and local people clear large swaths of forested land for agriculture, mostly illegally. It is imperative, therefore, that a soil erosion monitoring system for the Mt Kenya region is in place in order to understand the magnitude of, and be able to respond to, the increasing number of demands on this renewable resource. In this paper, we employ a simple regional-scale soil erosion modelling framework based on the Thornes model and suggest an operational methodology for quantifying and monitoring water runoff and soil erosion using multi-sensor and multi-temporal remote sensing data in a GIS framework. We compare the estimates of this study with general data on the severity of soil erosion over Kenya and with measured rates of soil loss at different locations over the area of study. The results show that the measured and estimated rates of erosion are generally similar and within the same order of magnitude. They also show that, over the last years, erosion rates are increasing in large parts of the region at an alarming rate, and that mitigation measures are needed to reverse the negative effects of uncontrolled socio-economic practices.

  5. Soil tillage erosion estimated by using magnetism of soils--a case study from Bulgaria.

    PubMed

    Jordanova, Diana; Jordanova, Neli; Atanasova, Anna; Tsacheva, Tsenka; Petrov, Petar

    2011-12-01

    A detailed field and laboratory study on small 0.84-ha test site of agricultural land near Sofia (Bulgaria) has been carried out in order to test the applicability of magnetic methods in soil erosion estimation in the particular case of strongly magnetic parent material. Field measurements of magnetic susceptibility were carried out with grid size of 6 m, resulting in 258 data points. Bulk soil material was gathered from 78 grid points. Natural, non-disturbed soil section was sampled near the agricultural field for reference profile of complete undisturbed soil. Surface susceptibility measurements reveal well-defined maxima down slope which, however, cannot be assigned directly to a certain depth interval, corresponding with susceptibilities along the non-disturbed soil profile. This is caused by the high magnetic susceptibility of the lithogenic coarse-grained magnetic fraction. Non-uniqueness is resolved by using magnetic susceptibility of coarse (1 mm > d > 63 μm) and fine (d < 63 μm) mechanical fractions and the parameter Δχ = 100*(χ (coarse) -χ (fine))/χ (bulk) (%). It shows increased values in the C-horizon of undisturbed soil profile, which corresponds to a certain part of the studied area. After the application of an empirical model to predict the values of magnetic parameter after tillage homogenization and removal of soil material from the surface, the amount of soil loss is estimated.

  6. The impact of climate change on soil erosion in 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. One of the expected changes to climate in the future is an increase in the frequency and inten...

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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

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

    PubMed

    Cong, Peifei; Yin, Guanghua; Gu, Jian

    2016-07-18

    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.

  13. 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.

  14. 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.

  15. 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.

  16. Moderate topsoil erosion rates constrain the magnitude of the erosion-induced carbon sink and agricultural productivity losses on the Chinese Loess Plateau

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Van Oost, K.; Chen, L.; Govers, G.

    2015-09-01

    Despite a multitude of studies, erosion rates as well as the contribution of different processes on Chinese Loess Plateau (CLP) remain uncertain. This makes it impossible to correctly assess the impact of conservation programs and the magnitude of the erosion-induced carbon sink. We used a novel approach, based on field evidence, to reassess erosion rates on the CLP before and after conservation measures were implemented. Our results show that the current average topsoil erosion rate is 3-9 times lower than earlier estimates suggested: most sediments are mobilised by gully erosion and/or landsliding. Under 2005 conditions, the combination of topsoil erosion, gully erosion and landslides mobilised 0.81 ± 0.23 Gt yr-1 of sediments and 4.77 ± 1.96 Tg yr-1 of soil organic carbon (SOC): the latter number sets the maximum magnitude of the erosion-induced carbon sink, which is ca. 4 times lower than other recent estimates suggest. The sediment fluxes we calculate are consistent with sediment yields measured in the Yellow River. The conservation programs implemented from the 1950s onwards reduced topsoil erosion from 0.51 ± 0.13 to 0.30 ± 0.08 Gt yr-1 while SOC mobilisation was reduced from 7.63 ± 3.52 to 4.77 ± 1.96 Tg C. Prior to 1950, a geomorphological equilibrium existed whereby the amount of sediment and carbon exported to the Bohai sea was similar to the amount of sediment eroded on the CLP, so that the erosion-induced carbon sink nearly equalled the amount of mobilised SOC. Conservation efforts and reservoir construction have disrupted this equilibrium and most eroded sediments and carbon are now stored on land where part of the SOC may decompose, thereby potentially lowering the strength of the erosion-induced carbon sink. Despite the fact that average topsoil losses on the CLP are still relatively high, the current level of topsoil erosion on the CLP is no major threat to the agricultural productivity of the area, mainly because fertilizer application has

  17. 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.

  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. 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...

  20. 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.

  1. 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

  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. WSA index as an indicator of soil degradation due to erosion

    NASA Astrophysics Data System (ADS)

    Jaksik, Ondrej; Kodesova, Radka; Schmidtova, Zuzana; Kubis, Adam; Fer, Miroslav; Klement, Ales; Nikodem, Antonin

    2014-05-01

    Knowledge of spatial distribution of soil aggregate stability as an indicator of soil degradation vulnerability is required for many scientific and practical environmental studies. The goal of our study was to assess predisposition of different soil types to change aggregate stability due to erosion. Five agriculture arable lands with different soil types were chosen. The common feature of these sites is relatively large slope and thus soils are impacted by water erosion. The first studied area was in Brumovice. The original soil type was Haplic Chernozem on loess, which was due to erosion changed into Regosol (steep parts) and Colluvial soil (base slope and the tributary valley). A similar process has been described at other four locations Vidim, Sedlcany, Zelezna and Hostoun, where the original soil types were Haplic Luvisol on loess and Haplic Cambisol on gneiss, Haplic Cambisol on shales, and Calcaric Cambisol on marlstone, respectively. The regular and semi-regular soil sampling grids were set at all five sites. The basic soil properties were measured and stability of soil aggregates (WSA index) was evaluated. In all cases, the higher aggregates stability was observed in soils, which were not (or only slightly) affected by water erosion and at base slope and the tributary valley (eroded soil particle accumulation). The lowest aggregate stability was measured at the steepest parts. When comparing individual sites, the highest WSA index, e.g. aggregate stability, was found in Sedlcany (Cambisol). Lower WSA indexes were measured on aggregates from Hostoun (Cambisol), Zelezna (Cambisol), Vidim (Luvisol) and the lowest values were obtained in Brumovice (Chernozem). The largest WSA indexes for Cambisols in comparison to Luvisols and Chernozem could be attributed to higher organic matter content and presence of iron oxides. Slightly higher aggregate stability of Luvisols in comparison to Chernozem, could be explained by the positive influence of clay (especially in

  4. Network for measuring runoff and water erosion in small agricultural cathments in Southern Spain

    NASA Astrophysics Data System (ADS)

    Taguas, E. V.; Gómez, J. A.; Boulal, H.; Gómez, H.; Vanwalleghem, T.; Pérez-Alcántara, R.; Peña, A.; Ayuso-Muñoz, J. L.; Giráldez, J. V.; Mateos, L.

    2010-05-01

    Water erosion is one of the major environmental threats to sustainability of agricultural production in Souther Spain. In Mediterranean climates, innapropriate soil management in steep or hilly landscapes causes intensive and extensive on-site and off-site damage. However, limited experimental information is available for fully understand the relationship between soil management practices and erosion at varying scales. This communication describes a network of five experimental catchments equipped with runoff and erosion monitoring devices established in the last five years in agricultural areas of Southern Spain. Three of the catchments are of small size (2 to 6.7 ha) and are covered by olive trees, a fourth one, of 20 ha, is cultivated with irrigated field crops, and the fifth catchment is located in an irrigation district where irrigated annual and tree crops coexist covering an area of 316 ha. Monitoring stations consist of a long-throated flume equipped with a untrasonic sensor to measure water depth, an ISCO water sampler, a rain gauge and a datalogger. This communication will present a preliminary comparison of runoff and sediment generated in the catchments during recent years, and it will discuss some of the main problems encountered in the establishment of the network and the future plans for upgrading the monitoring stations and analysing of results.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. Selecting and applying cesium-137 conversion models to estimate soil erosion rates in cultivated fields.

    PubMed

    Li, Sheng; Lobb, David A; Tiessen, Kevin H D; McConkey, Brian G

    2010-01-01

    The fallout radionuclide cesium-137 ((137)Cs) has been successfully used in soil erosion studies worldwide. However, discrepancies often exist between the erosion rates estimated using various conversion models. As a result, there is often confusion in the use of the various models and in the interpretation of the data. Therefore, the objective of this study was to test the structural and parametrical uncertainties associated with four conversion models typically used in cultivated agricultural landscapes. For the structural uncertainties, the Soil Constituent Redistribution by Erosion Model (SCREM) was developed and used to simulate the redistribution of fallout (137)Cs due to tillage and water erosion along a simple two-dimensional (horizontal and vertical) transect. The SCREM-predicted (137)Cs inventories were then imported into the conversion models to estimate the erosion rates. The structural uncertainties of the conversion models were assessed based on the comparisons between the conversion-model-estimated erosion rates and the erosion rates determined or used in the SCREM. For the parametrical uncertainties, test runs were conducted by varying the values of the parameters used in the model, and the parametrical uncertainties were assessed based on the responsive changes of the estimated erosion rates. Our results suggest that: (i) the performance/accuracy of the conversion models was largely dependent on the relative contributions of water vs. tillage erosion; and (ii) the estimated erosion rates were highly sensitive to the input values of the reference (137)Cs level, particle size correction factors and tillage depth. Guidelines were proposed to aid researchers in selecting and applying the conversion models under various situations common to agricultural landscapes.

  11. 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

  12. 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.

  13. Rapid assessment of soil erosion in the Rio Lempa Basin, Central America, using the universal soil loss equation and geographic information systems.

    PubMed

    Kim, John B; Saunders, Peter; Finn, John T

    2005-12-01

    Soil erosion is a severe problem for many developing regions that lack adequate infrastructure to combat the problem. The authors established a first-order method for prioritizing areas to be examined and remediated using preexisting data and expert knowledge where data are lacking. The Universal Soil Loss Equation was applied to the Rio Lempa Basin in Central America using geographic information systems and remote sensing technologies, and the estimated erosion rates were compared with sediment delivery ratios. Spatial analysis indicates that agriculture on very steep slopes contributes only a small fraction to the total estimated soil erosion, whereas agriculture on gentle and moderately steep slopes contributes a large fraction of the erosion. Although much of the basin is in El Salvador, the greatest estimated amount of erosion is from Honduras. Data quality and availability were impaired by a lack of coordination among agencies and across countries. Several avenues for improving the authors' methods are described.

  14. Delineating the Erosion-Potential of Agricultural Lands Within the Le Sueur Watershed Using Remotely Sensed Data and GIS

    NASA Astrophysics Data System (ADS)

    Maalim, F. K.; Melesse, A. M.; Thomas, A. R.; Belmont, P.; Azmera, L.; Jennings, C. E.

    2008-12-01

    The Le Sueur River, southern Minnesota, is the largest contributor of sediment to the Minnesota River, which is impaired for turbidity under Section 303d of the Clean Water Act. The agricultural fields within the Le Sueur River watershed were studied to assess their erosion potential and hence their contribution to the sediment loading problem in the study area. Soil type, slope, land cover and on-field land management practices were used to classify agricultural lands to determine their susceptibility to erosion. Field studies were conducted to determine the prevalent conditions that would be considered when analyzing the protection against erosion. Land cover types were identified and their geographic locations were noted for detection on sequential satellite images and mapping purposes. Land management practices were also identified in the field and their locations geo-registered. The slope profile of the Le Sueur watershed was derived from a Digital Elevation Model, while the seasonal land-cover was extrapolated from the land-cover ground-referencing exercise using satellite imagery. Soil maps of the different counties that constitute the Le Sueur watershed were also acquired and the spatial data was then integrated in a GIS to generate the erosion potential map. Plant physiology and morphology are important when developing a criterion for classifying land-cover types depending on the protection they confer against erosion. Land management practices influence the susceptibility of agricultural fields to erosion and these together with soil type and slope are useful erosion related properties on which to base the classification of the agricultural fields. Erosion potential is a dynamic aspect of agricultural lands and is a function of the combined prevalent factors. The set of factors used to study this aspect of agricultural lands were all very important but are by no means the only factors that should be considered when conducting such a study. The results

  15. Does control of soil erosion inhibit aquatic eutrophication?

    PubMed

    Ekholm, Petri; Lehtoranta, Jouni

    2012-01-01

    Much of the phosphorus (P) from erosive soils is transported to water bodies together with eroded soil. Studies clarifying the impact of soil erosion on eutrophication have sought largely to quantify the reserves of P in soil particles that can be desorbed in different types of receiving waters. Aquatic microbiology has revealed that the cycling of P is coupled to the availability of common electron acceptors, Fe oxides and SO₄, through anaerobic mineralization in sediments. Eroded soil is also rich in Fe oxides, and their effect on the coupled cycling of C, Fe, S, and P has been neglected in eutrophication research. Soil erosion, and its control, should therefore be studied by considering not only the processes occurring in the water phase but also those taking place after the soil particles have settled to the bottom. We propose that in SO₄-rich systems, Fe oxides transported by eroded soil may promote Fe cycling, inhibit microbial SO₄ reduction and maintain the ability of sediment to retain P. We discuss the mechanisms through which eroded soil may affect benthic mineralization processes and the manner in which soil erosion may contribute to or counteract eutrophication.

  16. 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

  17. 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

  18. 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...

  19. 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...

  20. 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

  1. Dynamics of Soil Organic Carbon and Microbial Biomass Carbon in Relation to Water Erosion and Tillage Erosion

    PubMed Central

    Xiaojun, Nie; Jianhui, Zhang; Zhengan, Su

    2013-01-01

    Dynamics of soil organic carbon (SOC) are associated with soil erosion, yet there is a shortage of research concerning the relationship between soil erosion, SOC, and especially microbial biomass carbon (MBC). In this paper, we selected two typical slope landscapes including gentle and steep slopes from the Sichuan Basin, China, and used the 137Cs technique to determine the effects of water erosion and tillage erosion on the dynamics of SOC and MBC. Soil samples for the determination of 137Cs, SOC, MBC and soil particle-size fractions were collected on two types of contrasting hillslopes. 137Cs data revealed that soil loss occurred at upper slope positions of the two landscapes and soil accumulation at the lower slope positions. Soil erosion rates as well as distribution patterns of the <0.002-mm clay shows that water erosion is the major process of soil redistribution in the gentle slope landscape, while tillage erosion acts as the dominant process of soil redistribution in the steep slope landscape. In gentle slope landscapes, both SOC and MBC contents increased downslope and these distribution patterns were closely linked to soil redistribution rates. In steep slope landscapes, only SOC contents increased downslope, dependent on soil redistribution. It is noticeable that MBC/SOC ratios were significantly lower in gentle slope landscapes than in steep slope landscapes, implying that water erosion has a negative effect on the microbial biomass compared with tillage erosion. It is suggested that MBC dynamics are closely associated with soil redistribution by water erosion but independent of that by tillage erosion, while SOC dynamics are influenced by soil redistribution by both water erosion and tillage erosion. PMID:23717530

  2. Dynamics of soil organic carbon and microbial biomass carbon in relation to water erosion and tillage erosion.

    PubMed

    Xiaojun, Nie; Jianhui, Zhang; Zhengan, Su

    2013-01-01

    Dynamics of soil organic carbon (SOC) are associated with soil erosion, yet there is a shortage of research concerning the relationship between soil erosion, SOC, and especially microbial biomass carbon (MBC). In this paper, we selected two typical slope landscapes including gentle and steep slopes from the Sichuan Basin, China, and used the (137)Cs technique to determine the effects of water erosion and tillage erosion on the dynamics of SOC and MBC. Soil samples for the determination of (137)Cs, SOC, MBC and soil particle-size fractions were collected on two types of contrasting hillslopes. (137)Cs data revealed that soil loss occurred at upper slope positions of the two landscapes and soil accumulation at the lower slope positions. Soil erosion rates as well as distribution patterns of the <0.002-mm clay shows that water erosion is the major process of soil redistribution in the gentle slope landscape, while tillage erosion acts as the dominant process of soil redistribution in the steep slope landscape. In gentle slope landscapes, both SOC and MBC contents increased downslope and these distribution patterns were closely linked to soil redistribution rates. In steep slope landscapes, only SOC contents increased downslope, dependent on soil redistribution. It is noticeable that MBC/SOC ratios were significantly lower in gentle slope landscapes than in steep slope landscapes, implying that water erosion has a negative effect on the microbial biomass compared with tillage erosion. It is suggested that MBC dynamics are closely associated with soil redistribution by water erosion but independent of that by tillage erosion, while SOC dynamics are influenced by soil redistribution by both water erosion and tillage erosion.

  3. 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

  4. 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

    The paper presents results of surface runoff, soil erosion and sediment transport modeling using Erosion 3D software - physically based mathematical simulation model, event oriented, fully distributed. Various methods to simulate technical soil-erosion conservation measures were tested, using alternative digital elevation models of different precision and resolution. Ditches and baulks were simulated by three different approaches, (i) by change of the land-cover parameters to increase infiltration and decrease flow velocity, (ii) by change of the land-cover parameters to completely infiltrate the surface runoff and (iii) by adjusting the height of the digital elevation model by "burning in" the channels of the ditches. Results show advantages and disadvantages of each approach and conclude suitable methods for combinations of particular digital elevation model and purpose of the simulations. Further on a set of simulations was carried out to model situations before and after technical soil-erosion conservation measures application within a small catchment of 4 km2. These simulations were focused on quantitative and qualitative assessment of technical soil-erosion control measures impact on soil erosion off-site effects within urban areas located downstream of intensively used agricultural fields. The scenarios were built upon a raster digital elevation model with spatial resolution of 3 meters derived from LiDAR 5G vector point elevation data. Use of this high-resolution elevation model allowed simulating the technical soil-erosion control measures by direct terrain elevation adjustment. Also the structures within the settlements were emulated by direct change in the elevation of the terrain model. The buildings were lifted up to simulate complicated flow behavior of the surface runoff within urban areas, using approach of Arévalo (Arévalo, 2011) but focusing on the use of commonly available data without extensive detailed editing. Application of the technical

  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. Watershed Sediment Losses to Lakes Accelerating Despite Agricultural Soil Conservation Efforts

    PubMed Central

    Heathcote, Adam J.; Filstrup, Christopher T.; Downing, John A.

    2013-01-01

    Agricultural soil loss and deposition in aquatic ecosystems is a problem that impairs water quality worldwide and is costly to agriculture and food supplies. In the US, for example, billions of dollars have subsidized soil and water conservation practices in agricultural landscapes over the past decades. We used paleolimnological methods to reconstruct trends in sedimentation related to human-induced landscape change in 32 lakes in the intensively agricultural region of the Midwestern United States. Despite erosion control efforts, we found accelerating increases in sediment deposition from erosion; median erosion loss since 1800 has been 15.4 tons ha−1. Sediment deposition from erosion increased >6-fold, from 149 g m−2 yr−1 in 1850 to 986 g m−2 yr−1 by 2010. Average time to accumulate one mm of sediment decreased from 631 days before European settlement (ca. 1850) to 59 days mm−1 at present. Most of this sediment was deposited in the last 50 years and is related to agricultural intensification rather than land clearance or predominance of agricultural lands. In the face of these intensive agricultural practices, traditional soil conservation programs have not decelerated downstream losses. Despite large erosion control subsidies, erosion and declining water quality continue, thus new approaches are needed to mitigate erosion and water degradation. PMID:23326454

  7. Watershed sediment losses to lakes accelerating despite agricultural soil conservation efforts.

    PubMed

    Heathcote, Adam J; Filstrup, Christopher T; Downing, John A

    2013-01-01

    Agricultural soil loss and deposition in aquatic ecosystems is a problem that impairs water quality worldwide and is costly to agriculture and food supplies. In the US, for example, billions of dollars have subsidized soil and water conservation practices in agricultural landscapes over the past decades. We used paleolimnological methods to reconstruct trends in sedimentation related to human-induced landscape change in 32 lakes in the intensively agricultural region of the Midwestern United States. Despite erosion control efforts, we found accelerating increases in sediment deposition from erosion; median erosion loss since 1800 has been 15.4 tons ha(-1). Sediment deposition from erosion increased >6-fold, from 149 g m(-2) yr(-1) in 1850 to 986 g m(-2) yr(-1) by 2010. Average time to accumulate one mm of sediment decreased from 631 days before European settlement (ca. 1850) to 59 days mm(-1) at present. Most of this sediment was deposited in the last 50 years and is related to agricultural intensification rather than land clearance or predominance of agricultural lands. In the face of these intensive agricultural practices, traditional soil conservation programs have not decelerated downstream losses. Despite large erosion control subsidies, erosion and declining water quality continue, thus new approaches are needed to mitigate erosion and water degradation.

  8. The Reduction of Partitioned Wind and Water Erosion by Conservation Agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil loss due to wind and water erosion degrades the soil and results in environmental problems downstream and downwind of the source field. Wind and water erosion may both occur to varying extents particularly in semi-arid environments. Soil conservation strategies require information about the p...

  9. Modeling the impacts of climate change and agricultural management practices on surface erosion in a dryland agricultural basin

    NASA Astrophysics Data System (ADS)

    Ottenbreit, E.; Adam, J. C.; Barber, M. E.

    2010-12-01

    The objective of this study is to investigate the effects of climate change and agricultural management practices on suspended sediment concentrations in the Potlach River basin in northwestern Idaho. Suspended sediment is a pollutant in many water systems and contributes to the impairment of streams. Conventional tillage practices and rain-on-snow events in the Palouse region of northern Idaho and eastern Washington can produce some of the highest sediment losses per acre in the United States. Climate change may lead to further problems as more frequent and intense winter storm events are predicted to occur. Many hydrological models have been developed which examine suspended sediment in river systems. The Potlatch River basin near Julietta, ID was examined using the Distributed Hydrology Soil Vegetation Model (DHSVM), which has a sediment module that includes surface erosion and channel sediment transport. DHSVM was calibrated and evaluated over the historical period of streamflow observations and was used to predict soil erosion rates and suspended sediment concentrations using a range of downscaled Global Climate Models (GCMs) emissions scenarios for the year 2045. Furthermore, the sensitivity of suspended sediment concentrations to conventional versus convservative tillage practices was explored. The results show that as the projected climate-driven intensity of storms increase, more sediment is predicted in the Potlatch River. Suspended sediment and streamflow are predicted to increase during the late fall through the early spring. This increase occurs during times of heightened runoff when suspended sediment concentration in the river is highest. Three tillage scenarios were incorporated into DHSVM for winter wheat: conventional till, reduced till, and no till. Erosion and suspended sediment were higher during storm events under conventional agricultural tillage scenarios. In the long-term, this research can lead to examination of the effects of climate

  10. Radionuclide determination techniques and spectroradiometry as tools to determine soil erosion

    NASA Astrophysics Data System (ADS)

    Rodriguez, E.; Suárez, J. A.; Gascó, C.; Schmid, T.; Rodriguez, M.

    2012-04-01

    Natural (210Pbunsupported, 226Ra, 210Po and 7Be) and artificial (239,240Pu, 137Cs) radionuclides are largely used as tools for studying and quantifying soil erosion. The global fallout of artificial radionuclides derived from weapons testing that took place during 1945's and 1960's was rapidly and firmly fixed in the soil surface, allowing to calculate further soil erosion by comparing inventories at individual sampling points with a reference inventory representing the local fallout input. This procedure is complemented with the 210Pbuns inventory calculation as indicator of the local average radionuclides deposition. Mathematical models, combining radionuclides inventories and soil properties, are lately applied to estimate the erosion rates. Spectroradiometry, is a further technique to determine soil erosion processes, by characterising soil surface reflectance values and relating these with soil properties such as structure, texture, mineral composition and organic matter content obtained from the laboratory analyses. The effect of erosion on these soils implies the presence of contrasting soil horizons emerging at the surface. In this case, surface reflectance measurements of soil samples are determined and associated to data obtained from the laboratory analyses. This technique uses spectral characteristics that can be extrapolated from the field scale to satellite coverage of an entire area. The aim of this work is to use both radionuclides determination and laboratory spectroradiometry techniques to evaluate soil erosion processes in well-developed soils (Alfisols) and its spatial distribution in an agricultural area near to Camarena within the Province of Toledo (Central Spain). The methodology includes the test of the sampling devices during the sampling campaign, the radionuclides analysis at different soil depths and the determination of their activity concentration levels by means of gamma spectrometry, complementing with alpha spectrometry to improve

  11. Soil erosion risk mapping: how to explain the stakeholders what lies behind?

    NASA Astrophysics Data System (ADS)

    Cerdan, Olivier; Degan, Francesca; Salvador-Blanes, Sebastien

    2014-05-01

    Recent demographic projections of the impact of global changes point to the need of increasing food and biomass production to meet expected global demand. This issue is particularly complex as it must comply with an increasing awareness that environmental quality must be preserved. Increased production can be achieved through either an intensification of agricultural practices or an increase of cultivated areas. In both cases, significant adverse effects are expected in terms of land degradation and its ability to maintain sustainable agricultural productivity. In this context, soil degradation vulnerability assessment is becoming more and more integrated in land management planning. Soil erosion being one of the major causes of soil degradation, the demand for soil erosion risk maps is increasing. However, the 2D representation of a process that shows strong non-linear dynamics in space and time is far from trivial. Important assumptions on the way to integrate these heterogeneities in time and space have to be made. How to integrate the crop rotation calendar and the climatic seasonal variability at the yearly scale? Or, how to characterise the erosion vulnerability of a geographical space that combines areas having different erosion risks? Moreover, other important questions arise with the resolution and the uncertainties associated with the available input data. And, last but not least, the final map needs, not only to integrate all these issues, but, more importantly, to be understandable by public managers. In this paper we illustrate the different difficulties inherent to soil erosion mapping, taking an example in different catchments of the Loire valley in France and present possible options to the spatial integration of both temporal and spatial variations in erosion risk.

  12. 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)

  13. 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.

  14. Modeling Size-Selective Soil Erosion and Nutrient Transport in Flume-Scale Experiments

    NASA Astrophysics Data System (ADS)

    Heng, B. P.; Sander, G. C.; Armstrong, A.; Chandler, J. H.; Quinton, J. N.; Scott, C. F.; Wheatley, A. D.

    2009-12-01

    The erosion of agricultural soils can have severe consequences for surface water quality as well as agricultural productivity. Where surface runoff occurs, it can carry sediment and nutrients quickly and in large quantities into water bodies. It is therefore important to be able to predict with some confidence their movement in overland flow. Since particulate pollutants (such as phosphorus) bind preferentially to the finer soil particles, we need to know the particle size distribution (PSD) of the sediment being transported as well as the bulk quantity. In this paper, we use a size-selective soil erosion model (coupled with the Saint-Venant equations for overland flow) to reproduce flume-scale experimental observations of sediment and nutrient transport dynamics under simulated rainfall. In view of the differences between experimental replicates, we model the experimental runs individually with separate sets of parameters. The model results are promising in relation to the PSD as well as the concentration of sediment in the surface runoff. We show that soil erosion and sediment transport can be significantly affected by seemingly minor topographical differences (measured by close range photogrammetry). We also analyze the optimized parameters for trends that give further insight into erosion processes. Finally, we present a single-parameter nutrient transport model that can reproduce with reasonable accuracy the dynamics of phosphorus export.

  15. 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.

  16. 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

  17. Decreasing soil erosion rates with evolving land-use techniques in a central European catchment

    NASA Astrophysics Data System (ADS)

    Larsen, Annegret; Heckmann, Tobias; Hans-Rudolf, Bork; Alexander, Fuelling

    2015-04-01

    Agricultural societies around the world have caused accelerated soil erosion. Soil erosion and a decrease in soil fertility may also have caused the abandonment of entire landscapes and the collapse of civilizations. In central Europe, Medieval land-use is thought to have lead to the largest loss of top soil in history, which in turn lead to a malnutrition of the population and abandonment of agricultural land. However, this might be only part of the picture, as people are also able to adapt to changing environmental conditions, including the type of land-use they adopt. Within a catchment in the central European mountain belt, we were able to distinguish the evolution between three main types of land-use techniques between ~ 900 AD and 1950 AD: horticulture, agriculture and shifting cultivation. We were able to relate these techniques with different soil erosion rates, which differ by an order of magnitude, ranging from 0.83 ± 0.09 mm/yr to 1.62 ± 0.17 mm/yr. Using high-resolution surface data and chrono-stratigraphical methods in combination with soil charcoal analysis, we were able to reconstruct past land-use techniques on a local scale. This illustrates that less erosive and more sustainable techniques were developed through time, and hypothesize that people were able to adapt to the less favorable environmental conditions by changing the cultivation techniques. Although cultural adaptation to changing environmental conditions has been extensively discussed, this study is able to quantitatively demonstrate improved soil management with evolving land-use in central Europe.

  18. 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

  19. Soil erosion under climate change in Great Britain: long-term simulations using high-resolution regional models

    NASA Astrophysics Data System (ADS)

    Ciampalini, Rossano; Kendon, Elizabeth; Constantine, José Antonio; Schindewolf, Marcus; Hall, Ian

    2016-04-01

    Twenty-first century climate change simulations for Great Britain reveal an increase in heavy precipitation that may lead to widespread soil loss and reduced soil carbon stores by increasing the likelihood of surface runoff. We find the quality and resolution of the simulated rainfall used to drive soil loss variation can widely influence the results. Hourly high definition rainfall simulations from a 1.5km resolution regional climate model are used to examine the soil erosion response in two UK catchments. The catchments have different sensitivity to soil erosion. "Rother" in West Sussex, England, reports some of the most erosive events that have been observed during the last 50 years in the UK. "Conwy" in North Wales, is resilient to soil erosion because of the abundant natural vegetation cover and very limited agricultural practises. We modelled with Erosion3D to check variations in soil erosion as influenced by climate variations for the periods 1996-2009 and 2086-2099. Our results indicate the Rother catchment is the most erosive, while the Conwy catchment is confirmed as the more resilient to soil erosion. The values of the reference-base period are consistent with the values of those locally observed in the previous decades. A soil erosion comparison for the two periods shows an increasing of sediment production (off-site erosion) for the end of the century at about 27% in the Rother catchment and about 50% for the Conwy catchment. The results, thanks to high-definition rainfall predictions, throw some light on the effect of climatic change effects in Great Britain.

  20. 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.

  1. Impacts of the post-fire erosion processes compared with the agricultural erosion rates for a mountain catchment in NW Iberia

    NASA Astrophysics Data System (ADS)

    Marisa Santos, Juliana; Nunes, João Pedro; Bernard-Jannin, Léonard; Gonzalez Pelayo, Oscar; Keizer, Jan Jacob

    2014-05-01

    Mediterranean ecosystems are very vulnerable to soil erosion by water due to particular characteristics of climate, lithology and land use history. Moreover, the foreseen climate changes might worsen land degradation and desertification, in which soil erosion has been classified as one of the most important driving forces. In this context, the frequent forest fires seen in some Mediterranean regions can case disturbances to vegetation cover and enhance soil erosion processes. This work addresses this issue for the Caramulo mountain range, NW Iberia. In the past century, large land use changes occurred due to massive afforestation. Changes from mixed natural forest cover and shrublands to Pine, the introduction of Eucalyptus plantations and, more recently, a trend for the substitution of pines by eucalypts, are the evidence of a large and rapid land use change in the last decades. Forest fires started to occur as afforestation proceeded, as a consequence of the disappearance of pasturage and accumulation of highly inflammable material; they became more frequent after the 1960's and became a determinant factor for land use changes in this region. Data collection focused on the Macieira de Alcoba catchment, a headwater agro-forested catchment (94 ha) located in this region. It has a wet Mediterranean climate, with an average annual rainfall of about 1300 mm (2002-2012), concentrated in autumn and winter, while spring and summer are dryer seasons. The mean annual temperature is 14°C and in summer it can reach 35°C. The land use is mixed, with forest and agriculture lands covering respectively 60 and 35% of the catchment area, 5% being built-up areas in the village of Macieira de Alcoba. In the last decades, this catchment suffered several forest fires (in 1969, 1986, 1991, and 2011). Erosion processes are related with periods of low vegetation cover in autumn in fields with a pasture-corn rotation, but also with forest plantations after clear-cutting and especially

  2. Grass mulching effect on infiltration, surface runoff and soil loss of three agricultural soils in Nigeria.

    PubMed

    Adekalu, K O; Olorunfemi, I A; Osunbitan, J A

    2007-03-01

    Mulching the soil surface with a layer of plant residue is an effective method of conserving water and soil because it reduces surface runoff, increases infiltration of water into the soil and retard soil erosion. The effectiveness of using elephant grass (Pennisetum purpureum) as mulching material was evaluated in the laboratory using a rainfall simulator set at rainfall intensities typical of the tropics. Six soil samples, two from each of the three major soil series representing the main agricultural soils in South Western Nigeria were collected, placed on three different slopes, and mulched with different rates of the grass. The surface runoff, soil loss, and apparent cumulative infiltration were then measured under each condition. The results with elephant grass compared favorably with results from previous experiments using rice straw. Runoff and soil loss decreased with the amount of mulch used and increased with slope. Surface runoff, infiltration and soil loss had high correlations (R = 0.90, 0.89, and 0.86, respectively) with slope and mulch cover using surface response analysis. The mean surface runoff was correlated negatively with sand content, while mean soil loss was correlated positively with colloidal content (clay and organic matter) of the soil. Infiltration was increased and soil loss was reduced greatly with the highest cover. Mulching the soils with elephant grass residue may benefit late cropping (second cropping) by increasing stored soil water for use during dry weather and help to reduce erosion on sloping land.

  3. 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

  4. 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 the opportunity to further improve the monitoring of earth finite soil resources.

  5. Resisting Erosion: Quantifying Controls on Soil Production

    NASA Astrophysics Data System (ADS)

    Byersdorfer, J. P.; Burke, B. C.; Heimsath, A.; Dade, B.

    2005-12-01

    Soil production from a bedrock surface is influenced by climate, mineralogy, seismic activity, and glacial history. This study examines the relationships between chemical weathering, soil production rates, and new observations of physical strength and, microscopic weathering textures of saprolite in granitic terrain. Our study areas are soil-mantled hillslopes on two well-studied geographically disparate sites: Points Reyes National Seashore, CA and Nunnock River, Australia. Soil production rates at both sites were determined with in situ produced cosmogenic nuclides and decrease exponentially with increasing soil thickness. We hypothesize that saprolite strength should i) constrain soil production rates, and ii) diminish with degree of alumino-silicate weathering. Until now, these ideas have not been systematically tested. To measure the physical competency of the saprolite we use conventional shear vane and dynamic cone penetrometers tests. We find that soil production rates and resistance to penetration each exhibit maximal values at the hillcrest and diminish with increasing soil cover and distance downslope as the soil thickness increases. Conversely, saprolite shear strength increases under thicker soil profiles that accompany lower soil production rates and decreasing values of Kr ratio (SiO2/Al2O3 + Fe2O3). We speculate that the contrasting decrease in penetration resistance and increasing shear strength of saprolite is due to accumulation of clays with increasing residence time at the base of the soil column. The mechanistic significance of saprolite strength as a constraint on soil production depends on whether the soil producing processes are dominated by penetration (e.g. tree roots) or shearing forces (e.g. burrowing mammals).

  6. 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

  7. Testing the soil production paradigm: Role of catchment-mean erosion rate in colluvial soil production

    NASA Astrophysics Data System (ADS)

    Foster, M.; Whipple, K. X.; Heimsath, A. M.

    2013-12-01

    Colluvial soil thickness is a fundamental characteristic of the critical zone, playing an essential role in hydrology, ecology, the action of biogeochemical cycles, and erosion and transport processes. Colluvial soil thickness reflects a balance between soil production (the conversion of rock to mobile regolith) and erosion. Further, well-established theory predicts that: (1) mean soil thickness decreases with increasing catchment-mean erosion rate and (2) that soil-mantled landscapes give way to rocky ones when catchment-mean erosion rate exceeds the climate- and lithology-controlled maximum soil production rate that occurs on bare-rock surfaces or under a thin soil cover. This critical erosion rate is thus expected to be associated with a sudden and profound change in hydrology, ecology, biogeochemical processes, and erosion/sediment transport processes. Despite the pervasive acceptance of this idea, it has never been systematically tested and even casual observations reveal that it may be flawed. Indeed, a global compilation of available soil production rate constants suggests that erosion rate is the strongest control, implying that well-established theory is fundamentally incorrect. Although the efficiency of soil production is thought to be set by climate and lithology alone, recent work suggests that it increases in concert with catchment-mean erosion rates and associated changes in process dominance and landscape morphology; existing models may exaggerate changes in critical-zone properties in response to tectonic uplift. Three fundamental observations support this claim: (1) observed soil thicknesses vary little across 2 orders of magnitude variation in erosion rate in published soil-production studies; (2) soil cover persists in landscapes eroding at well above the putative soil-production "speed limit"; and (3) published estimates of the rate constant in the exponential soil-production function increases linearly with catchment-mean erosion rate

  8. 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

    quantified for 53 soil profiles using the artificial fallout radionuclide 137Cs. Our results indicate that the existing approaches ignore the erosion-induced reduction of in-situ soil CO2 emission from agriculturally eroding sites, and may therefore significantly overestimate the potential of reforestation in enhancing carbon sequestration. When the elimination of the erosion-induced sink term is accounted for, and for a range of protection levels of buried SOC in the fluvial system, we estimate that the C sequestration potential of re-vegetation may be overestimated by 25% to 50% for a period of c. 100 years.

  9. 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

  10. 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

  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. 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

  13. Inherent agricultural constraints in Allegheny Plateau soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    World population increases demand increased agricultural production. This can be accomplished through improved cultivars and production techniques or increased use of previously marginal agricultural regions. In the Allegheny Plateau (AP) region of the Appalachian Mountains, acid soils with toxic ...

  14. 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

  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. Aerosol emissions from biochar-amended agricultural soils

    NASA Astrophysics Data System (ADS)

    Ravi, S.; Sharratt, B. S.; Li, J. J.; Olshvevski, S.; Meng, Z.; Zhang, J.

    2015-12-01

    Agricultural production is a major contributor to anthropogenic greenhouse gas emissions and associated global warming. In this regard, novel carbon sequestration strategies such as large-scale biochar application may provide sustainable pathways to increase the terrestrial storage of carbon in agricultural areas. Biochar has a long residence time in the soil and hence understanding the soil properties affected by biochar addition needs to be investigated to identify the tradeoffs and synergies of large-scale biochar application. Even though several studies have investigated the impacts of biochar application on a variety of soil properties, very few studies have investigated the impacts on soil erosion, in particular wind (aeolian) erosion and subsequent particulate emissions. Using a combination of wind tunnel studies and laboratory experiments, we investigated the dust emission potential of biochar-amended agricultural soils. We amended biochar (unsieved or sieved to appropriate particle size; application rates ranging from 1 - 5 % of the soil by weight) to three soil types (sand, sandy loam, and silt loam) and estimated the changes in threshold shear velocity for wind erosion and dust emission potential in comparison to control soils. Our experiments demonstrate that emissions of fine biochar particles may result from two mechanisms (a) very fine biochar particles (suspension size) that are entrained into the air stream when the wind velocity exceeds the threshold, and (b) production of fine biochar particles originating from the abrasion by quartz grains. The results indicate that biochar application significantly increased particulate emissions and more interestingly, the rate of increase was found to be higher in the intermediate range of biochar application. As fine biochar particles effectively adsorb/trap contaminants and pathogens from the soil, the preferential erosion of fine biochar particles by wind may lead to concentration of contaminants in the

  17. 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

  18. 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

  19. 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.

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

    NASA Astrophysics Data System (ADS)

    Webb, N.; Herrick, J.; Duniway, M.

    2013-12-01

    This work explores how soil erosion assessments can be structured in the context of ecological sites and site dynamics to inform systems for managing accelerated soil erosion. We evaluated wind and water erosion rates for five ecological sites in southern New Mexico, USA, using monitoring data and rangeland-specific wind and water erosion models. Our results show that wind and water erosion can be highly variable within and among ecological sites. Plots in shrub-encroached and shrub-dominated states were consistently susceptible to both wind and water erosion. However, grassland plots and plots with a grass-succulent mix had a high indicated susceptibility to wind and water erosion respectively. Vegetation thresholds for controlling erosion are identified that transcend the ecological sites and their respective states. The thresholds define vegetation cover levels at which rapid (exponential) increases in erosion rates begin to occur, suggesting that erosion in the study ecosystem can be effectively controlled when bare ground cover is <20% of a site or total ground cover is >50%. Similarly, our results show that erosion can be controlled when the cover of canopy interspaces >50 cm in length reaches ~50%, the cover of canopy interspaces >100 cm in length reaches ~35% or the cover of canopy interspaces >150 cm in length reaches ~20%. This process-based understanding can be applied, along with knowledge of the differential sensitivity of vegetation states, to improve erosion management systems. 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 sites to erosion. Land use impacts that are constrained within the natural variability of sites should not result in accelerated soil erosion. Evaluating land condition against the erosion thresholds and natural variability of ecological sites will enable improved identification of where and when accelerated soil

  1. 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

  2. Forest Cover Change and Soil Erosion in Toledo's Rio Grande Watershed

    NASA Astrophysics Data System (ADS)

    Chicas, S.; Omine, K.

    2015-04-01

    Toledo, the southernmost district, is the hub of Belize's Mayan population, descendants of the ancient Mayan civilization. The Toledo District is primarily inhibited by Kekchi and Mopan Mayans whose subsistence needs are met by the Milpa slash-and-burn agricultural system and the extraction of forest resources. The poverty assessment in the country indicates that Toledo is the district with the highest percentage of household an individual indigence of 37.5 % and 49.7 % respectively. Forest cover change in the area can be attributed to rapid population growth among the Maya, together with increase in immigration from neighboring countries, logging, oil exploration and improvement and construction of roads. The forest cover change analysis show that from 2001 to 2011 there was a decrease of Lowland broad-leaved wet forest of 7.53 km sq, Shrubland of 4.66 km sq, and Wetland of 0.08 km sq. Forest cover change has resulted in soil erosion which is causing the deterioration of soils. The land cover types that are contributing the most to total erosion in the Rio Grande watershed are no-forest, lowland broad-leaved wet forest and submontane broad-leaved wet forest. In this study the Revised Universal Soil Loss Equation (RUSLE) was employed in a GIS platform to quantify and assess forest cover change and soil erosion. Soil erosion vulnerability maps in Toledo's Rio Grande watershed were also created. This study provides scientifically sound information in order to understand and respond effectively to the impacts of soil erosion in the study site.

  3. Soils and the variability of erosion in steepland catchments

    NASA Astrophysics Data System (ADS)

    Roering, J.; Reckling, T.; Almond, P.; Booth, A.

    2008-12-01

    Efforts to model and interpret the evolution of landscapes are often hindered by the lack of data that describe variability in erosion rates for real landscapes. Nearly all landscape evolution simulations are evaluated after the model surface attains a precise balance between rock uplift and erosion, yet it is highly unlikely that real landscapes achieve this steady-state condition across broad areas. Because most erosion rate data are obtained via catchment-averaged analysis of cosmogenic radionuclides or suspended sediment, we have sparse information on the variability of erosion rates in upland regions. Here, we use a novel analysis of hilltop soil properties, in particular rubification, to calculate soil residence time (which is inversely related to erosion rate) for two catchments in the Oregon Coast Range (OCR). Using a soil chronosequence derived from dated fluvial terraces along the Siuslaw river, we observed systematic reddening (as well as geochemical alteration) of soils over ~1 Ma. When coupled with a continuity- based equation for soil production and transport, our weathering (or reddening) function enables us to estimate soil residence time based on the digitally-derived redness value of dried, crushed, sieved, pressed, and photographed soil samples. We collected >200 soil samples from hilltops along the drainage divides of Hoffman and Jump Creeks and generated a soil residence time distribution for both sites. Hoffman Ck features uniformly-spaced ridge-valley terrain (as determined by wavelet transformation of topographic data) characteristic of the OCR and its outlet directly connects with a tide-dominated reach of the Siuslaw river. In contrast, the nearby, low-gradient, irregularly-dissected Jump Ck catchment has an outlet that flows over a >30m igneous dike-controlled waterfall that retards the upstream passage of baselevel lowering. Consistent with these opposing geomorphic settings, Hoffman Ck soils are young with little variability (10 +14

  4. 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...

  5. 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...

  6. 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.

  7. 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.

  8. Incorporating Information on (micro)Topography when Modelling Soil Erosion at the Watershed Scale

    NASA Astrophysics Data System (ADS)

    Cerdan, O.

    2015-12-01

    In the context of shallow flows, the spatial distribution of the flow is highly influenced by the micro-topography. For instance, local oriented depressions may exist in which the flow depth and velocity may exceed the threshold for soil erosion initiation. If a mean uniform flow shear stress is used to characterize the area, it would be smaller and therefore may not initiate erosion. However, management of water and sediment fluxes requires analysis and modeling at the watershed scale in order to integrate the relations between upstream and downstream areas. At this scale, high resolution information on the microtopography is usually not always available and would anyway require too extensive computation resources to be explicitly integrated in modelling attempt. Moreover, in agricultural context, this information is likely to change during the year depending on the agricultural practices. In this context, the objective of this study is to propose a parameterisation of the influence of microtopography on erosion into the framework of the shallow water equation. For each cell, the proportion of wetted area is used as a microtopography indicator. For the case of erosion, the system is coupled to the sediment transport equations. In such context, an additional equation describing the micro-topography evolution caused by erosion is introduced. Different case study will be presented to investigate the potential of the approach.

  9. Bringing together monitoring of soil erosion and rainfall simulations

    NASA Astrophysics Data System (ADS)

    Engels, B.; Seeger, M.; Ries, J. B.

    2009-04-01

    Soil erosion is a non linear process depending on soil conditions and the rainfall characteristics. As a consequence, the monitoring and quantification of soil erosion and sediment yield faces great difficulties related to the occurrence of erosional events and the variability of soil charcateristics. Numerous research groups have been using rainfall simulators to quantify soil erosion under reproducible conditions, especially facing the comparision of different land use and soil management systems. But there is only little evidence of the comparability of the results of rainfall simulations with the real soil erosion. As a consequene, the following questions arise: reflect both methods the same or similar process complexes? Which orders of magnitude or overland flow and erosion do they reflect? Resuming: are the results comparable? For adressing this questions, we compared two adyacent parcels on a SSW exposed slope (steepness 35 %) on slate vineyard soils. One of the parcels was stubbed right before the installation of the sediment traps, the other one remained unchanged. 4 rainfall collectors were installed on soil surface, and daily rainfall amount was recorded in 3 meteorological stations only few kilometers away. The traps and the collectors were cleaned out after every large rainfall event. 15 rainfall simulations (4 on the unchanged area, 11 on the stubbed surface) were performed with a portable, pressure driven nozzle rinfall simulator, generating rainfall with an intensity of 40 mm h-1 during 30 min on a plot with 60 cm diameter. Surface runoff and sediment yield was collected in 5 min intervals during the experiment's duration. The runoff collected in traps on the stubbed parcel was 10 to 15 times higher than in the unchanged vineyard. Soil loss was up to 6 times higher. Contrasting with this, the results from rainfall simulations showed a very much lower difference between both sites. The portable rainfall simulator used in this study is able to reflect

  10. 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.

  11. Erosion processes by water in agricultural landscapes: a low-cost methodology for post-event analyses

    NASA Astrophysics Data System (ADS)

    Prosdocimi, Massimo; Calligaro, Simone; Sofia, Giulia; Tarolli, Paolo

    2015-04-01

    Throughout the world, agricultural landscapes assume a great importance, especially for supplying food and a livelihood. Among the land degradation phenomena, erosion processes caused by water are those that may most affect the benefits provided by agricultural lands and endanger people who work and live there. In particular, erosion processes that affect the banks of agricultural channels may cause the bank failure and represent, in this way, a severe threat to floodplain inhabitants and agricultural crops. Similarly, rills and gullies are critical soil erosion processes as well, because they bear upon the productivity of a farm and represent a cost that growers have to deal with. To estimate quantitatively soil losses due to bank erosion and rills processes, area based measurements of surface changes are necessary but, sometimes, they may be difficult to realize. In fact, surface changes due to short-term events have to be represented with fine resolution and their monitoring may entail too much money and time. The main objective of this work is to show the effectiveness of a user-friendly and low-cost technique that may even rely on smart-phones, for the post-event analyses of i) bank erosion affecting agricultural channels, and ii) rill processes occurring on an agricultural plot. Two case studies were selected and located in the Veneto floodplain (northeast Italy) and Marche countryside (central Italy), respectively. The work is based on high-resolution topographic data obtained by the emerging, low-cost photogrammetric method named Structure-from-Motion (SfM). Extensive photosets of the case studies were obtained using both standalone reflex digital cameras and smart-phone built-in cameras. Digital Terrain Models (DTMs) derived from SfM revealed to be effective to estimate quantitatively erosion volumes and, in the case of the bank eroded, deposited materials as well. SfM applied to pictures taken by smartphones is useful for the analysis of the topography

  12. 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

  13. 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.

  14. Soil maps as data input for soil erosion models: errors related to map scales

    NASA Astrophysics Data System (ADS)

    van Dijk, Paul; Sauter, Joëlle; Hofstetter, Elodie

    2010-05-01

    Soil erosion rates depend in many ways on soil and soil surface characteristics which vary in space and in time. To account for spatial variations of soil features, most distributed soil erosion models require data input derived from soil maps. Ideally, the level of spatial detail contained in the applied soil map should correspond to the objective of the modelling study. However, often the model user has only one soil map available which is then applied without questioning its suitability. The present study seeks to determine in how far soil map scale can be a source of error in erosion model output. The study was conducted on two different spatial scales, with for each of them a convenient soil erosion model: a) the catchment scale using the physically-based Limbourg Soil Erosion Model (LISEM), and b) the regional scale using the decision-tree expert model MESALES. The suitability of the applied soil map was evaluated with respect to an imaginary though realistic study objective for both models: the definition of erosion control measures at strategic locations at the catchment scale; the identification of target areas for the definition of control measures strategies at the regional scale. Two catchments were selected to test the sensitivity of LISEM to the spatial detail contained in soil maps: one catchment with relatively little contrast in soil texture, dominated by loess-derived soil (south of the Alsace), and one catchment with strongly contrasted soils at the limit between the Alsatian piedmont and the loess-covered hills of the Kochersberg. LISEM was run for both catchments using different soil maps ranging in scale from 1/25 000 to 1/100 000 to derive soil related input parameters. The comparison of the output differences was used to quantify the map scale impact on the quality of the model output. The sensitivity of MESALES was tested on the Haut-Rhin county for which two soil maps are available for comparison: 1/50 000 and 1/100 000. The order of

  15. Hydrological and erosion processes in terraced agricultural fields: observations from a wet Mediterranean region in northern Portugal

    NASA Astrophysics Data System (ADS)

    Nunes, João Pedro; Bernard-Jannin, Léonard; Rodriguez-Blanco, María Luz; Marisa Santos, Juliana; Oliveira Alves Coelho, Celeste; Keizer, Jan Jacob

    2015-04-01

    Traditional agriculture in the mountainous humid regions of the northwestern Iberian peninsula has relied on terraces for soil retention. In the last decades, a strong afforestation (in many cases with commercial species) has led to the appearance of large forest areas coexisting with traditional agricultural landscapes. Soil erosion research in this region has therefore focused on the impact of forest management practices and associated disturbances such as wildfires. However, there has been little research on the impacts of traditional terracing practices on erosion, and therefore it has been difficult to connect forest research with the wider issue of sediment connectivity in this complex agroforestry landscape. This work tried to address this research gap by monitoring an agricultural terrace in the Caramulo mountains, northern Portugal, during two years. The field site is located in a humid Mediterranean climate region, with c. 1500 mm/y rainfall, overlaying granite bedrock; agricultural practices are a traditional rotation between winter pasture and summer (irrigated) corn cultivation. During this period, the soil properties of the terrace were characterized, and there was a continuous monitoring of rainfall, soil moisture and surface runoff at the outlet, as well as 1 or 2-weekly collections of runoff to measure sediment yield. Occasional measurements of vegetation cover and erosion features (rills) within the plot were also made. Preliminary results indicate that runoff generation occurred mostly due to saturation-excess, possibly linked with the accumulation of groundwater in the lower layers of the soil. After one of the largest events, there was a clear inflow of runoff from outside the terrace, through either the irrigation network linking all terraces or by resurfacing of groundwater. Sediment yield was linked with runoff, but sediment concentration was linked with vegetation cover and was highest during the early stages of pasture growth. However

  16. 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

  17. 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.

  18. 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...

  19. 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

  20. Assessing nutrient losses with soil erosion under different tillage systems and their implications on water quality

    NASA Astrophysics Data System (ADS)

    Munodawafa, Adelaide

    An increased public perception of the role of agriculture in non-point source pollution has stimulated the need for information on the effect of conventional and sustainable agricultural management systems on water quality. While information on run-off and soil erosion is readily available in Zimbabwe, there is dearth of knowledge on the relative losses of nutrients as a result of soil erosion and their effect on water quality. This study sought to quantify the amount of nutrients lost as a result of soil erosion and thus enable conclusions to be drawn on the implications on water quality. Research work was carried out in the semi-arid region of Zimbabwe under granite-derived, inherently infertile sandy soils. Soil erosion was quantified under three tillage systems conventional tillage (CT); mulch ripping (MR); tied ridging (TR) over three years. Run-off and sediments were analysed for N, P and K. The results showed that N and K losses were significantly higher ( p < 0.001) under CT (15.8 and 34.5 kg ha -1 yr -1, respectively) compared to the MR (2.3 and 0.6 kg ha -1 yr -1, respectively) and TR (2.7 and 4.3 kg ha -1 yr -1, respectively). Due to the immobility of P and its small quantities in these soils, P losses were also low across all treatments (<1 kg ha -1 yr -1), however CT had significantly higher losses ( p < 0.001). The study showed that CT results in high losses of nutrients, which would in turn reduce the quality of surface waters, due to high nutrient concentrations of especially, N, which stimulates the growth of algae and other aquatic weeds. The gravity of the situation would be higher, where soils are more fertile. MR and TR were efficient in reducing soil erosion and thus nutrient losses with run-off and sediments. Pollution of surface water sources can be greatly reduced if conservation tillage systems are used.

  1. 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.

  2. Monitoring soil erosion in terraced catchments in Mediterranean regions: a field experiment in Cyprus

    NASA Astrophysics Data System (ADS)

    Camera, Corrado; Djuma, Hakan; Zoumides, Christos; Eliades, Marinos; Bruggeman, Adriana; Abate, Dante; Faka, Marina; Hermon, Sorin

    2016-04-01

    Terraces retained by dry-stone walls are very common features in mountainous Mediterranean environments. These structures provide accessible agricultural land on steep slopes, favoring water infiltration and reducing water runoff and soil erosion. However, during the last decades, an increasing trend of agricultural land abandonment has resulted in a lack of maintenance of the terrace walls and the onset of a general process of land degradation. The objective of this study is the quantification of soil erosion in a small terraced catchment (10,000 m2), located on the north-eastern slope of the Troodos Mountains (Cyprus), at an elevation of 1,300 m a.s.l. The catchment is cultivated with vineyards and it is representative of the main agricultural land use in the Troodos region. Soil erosion is measured by sediment traps and laser scans are made to assess changes in terrace geometry. In addition, a weather station measuring rainfall, temperature and relative humidity has been installed in the catchment, along with 18 soil moisture sensors, to relate soil erosion processes with climate and (sub)surface hydrology. A total of 10 sediment traps, five pairs, have been installed in the study site, catching five well-maintained sections of a dry-stone wall and five degraded (collapsed) sections. Each trap is 1 m wide. In detail, two terraces, 11 and 14 m long, located at the same elevation and separated by a strip of natural vegetation, are monitored with four and six traps, respectively. To get a complete picture of the erosion processes occurring on the selected area, the trap pairs collect sediment from both the collapsed and the well maintained wall sections of the two terraces. In addition, terrace area of two traps is delineated by metal borders (1x4 m2) to relate erosion rates to a known drainage area. The sediment traps are emptied after all rainfall events. At the beginning and end of the rainy season, a laser scanning survey of a terrace located uphill of the ones

  3. 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

  4. Timing the carbon cycle: how far does the soil erosion benefit stretch ?

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Govers, G.; Van Oost, K.; Merckx, R.

    2012-04-01

    Several papers have now convincingly shown that, on the short term, the intensification of soil erosion due to human activities does not lead to a massive emission of soil organic carbon. Rather, agricultural soil erosion may be responsible for a relatively small carbon sink. This conclusion is mainly based on the fact that a large fraction of the eroded carbon is dynamically replaced by additional soil carbon uptake at eroding sites and the behaviour of the carbon stores created by deposition. Over decadal time periods a large amount of the deposited carbon is indeed retained within the soil reservoir, thereby leading to net extra carbon storage. It is still unclear, however, how stable such stores are over longer time spans. We therefore sampled both active and historical colluvial depositional stores in different landscape settings in the Loess Belt of central Belgium. We determined the total amount of carbon stored as well as the variation in its stable isotope composition and a limited number of samples were subjected to incubation runs. The age of the deposits was determined as accurately as possible by measuring total phosphorous as well as 137Cs analysis as well as by interpreting historical maps and aerial photographs. We used our data to calibrate and validate a simple soil carbon model using two carbon pools only. While the values of the calibration parameters that we obtained for our different sites varied, the results with respect to the lifespan of a soil carbon store created by deposition were consistent. Model simulations show that, under realistic conditions, depositional carbon stores reach equilibrium after 300-1500 years, depending on the deposition rate. At this stage, 20 to 50 % of the deposited soil organic carbon is still present in the colluvium. When accounting for the effects of soil erosion on the global carbon cycle it is therefore important to consider the dynamics of depositional stores over longer time spans. Our analysis shows that

  5. Timing the Carbon Cycle: how far does the Soil Erosion Benefit Stretch ?

    NASA Astrophysics Data System (ADS)

    Govers, G.; Wang, Z.; Van Oost, K.; Merckx, R.

    2011-12-01

    Several papers have now convincingly shown that, on the short term, the intensification of soil erosion due to human activities does not lead to a massive emission of soil organic carbon. Rather, agricultural soil erosion may be responsible for a relatively small carbon sink. This conclusion is mainly based on the fact that a large fraction of the eroded carbon is dynamically replaced by additional soil carbon uptake at eroding sites and the behaviour of the carbon stores created by deposition. Over decadal time periods a large amount of the deposited carbon is indeed retained within the soil reservoir, thereby leading to net extra carbon storage. It is still unclear, however, how stable such stores are over longer time spans. We therefore sampled both active and historical colluvial depositional stores in different landscape settings in the Loess Belt of central Belgium. We determined the total amount of carbon stored as well as the variation in its stable isotope composition and a limited number of samples were subjected to incubation runs. The age of the deposits was determined as accurately as possible by measuring total phosphorous as well as 137Cs analysis as well as by interpreting historical maps and aerial photographs. We used our data to calibrate and validate a simple soil carbon model using two carbon pools only. While the values of the calibration parameters that we obtained for our different sites varied, the results with respect to the lifespan of a soil carbon store created by deposition were consistent. Model simulations show that, under realistic conditions, depositional carbon stores reach equilibrium after 300-1500 years, depending on the deposition rate. At this stage, 20 to 50 % of the deposited soil organic carbon is still present in the colluvium. When accounting for the effects of soil erosion on the global carbon cycle it is therefore important to consider the dynamics of depositional stores over longer time spans. Our analysis shows that

  6. Soil erosion and sediment yield prediction on catchment and regional scale using a process based simulation model

    NASA Astrophysics Data System (ADS)

    Schindewolf, Marcus; Schmidt, Jürgen

    2010-05-01

    The prevention of erosion is one of the main issues in the EU-Water Framework Directive (WFD) and the European Agricultural Fund for Rural Development (EAFRD). Planning and dimensioning of soil conservation measures require reliable and detailed information on the temporal and spatial distribution of soil detachment, soil transport and deposition. Soil erosion models are increasingly used, in order to simulate the physical processes involved and to predict the effects of soil erosion control measures. In this study the EROSION 3D simulation model is used for surveying soil erosion and deposition on the catchment scale covering the entire state of Saxony/Germany (18.500 km²). EROSION 3D is a distributed, extensively validated GIS based soil loss and deposition model including sediment delivery to surface water bodies. However, the application of the model for an entire state is a new challenge, because of the enormous data requirements and complex data processing operations prior to simulation. In this context the study includes the compilation, validation and generalisation of existing land use and soil data in order to generate a consistent EROSION 3D input dataset for the entire state of Saxony. As a part of this process the interface software DPROC allows to transfer the original soil and land use data into model specific data. The project aims to extend the interface software DPROC by an interactive GIS-component which enables the user to select arbitrary hydrological watersheds including the related soil and land use data. Based on these data DPROC automatically creates the according EROSION 3D input files using a relational database of primary data and model specific data. DPROC uses parameter transfer tables in order to specify the relationship between primary soil and land use data and model specific data. This combined methodology provides different risk assessment maps for certain demands on the regional scale of a Federal State. Besides soil loss and

  7. 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

  8. Soil erosion in the Swiss midlands: Results of a 10-year field survey

    NASA Astrophysics Data System (ADS)

    Prasuhn, Volker

    2011-03-01

    Long-term field monitoring of soil erosion by water was conducted on arable land in the Swiss midlands. All visible erosion features in 203 fields were continuously mapped and quantified over 10 years. The eroded soil volume associated with linear erosion features was calculated by measuring the length and cross-sectional area in rills at representative positions and the extent of interrill erosion was estimated. Averaged across the 10 study years, just under one-third (32.2%) of the fields exhibited erosion. With 0.75 t ha -1 yr -1 (mean) and 0.56 t ha -1 yr -1 (median), the average annual soil loss of the region was relatively small. The year-to-year variation in soil loss of the region was great and ranged from 0.16 to 1.83 t ha -1 yr -1. The maximum annual soil erosion in a single field was 96 t yr -1 or 58 t ha -1 yr -1, thus demonstrating that only a few erosion events on a few fields may decisively contribute to the total extent of soil erosion in a region. Linear and interrill erosion accounted for 75% and 25% of total soil loss, respectively. Wheel tracks, furrows, headlands, and slope depressions were important on-site accelerators of erosion. Run-on from adjacent upslope areas was an important trigger of erosion. Of the soil moved by erosion, 52% was deposited within the field of origin. A high proportion (72%) of the linear erosion features caused off-site damage. Part of the total eroded soil (20%) was transported into water, thereby contributing to their contamination. The long-term field assessment of soil erosion helps to fill existing knowledge gaps concerning temporal and spatial variability of soil erosion on arable land, the extent and severity of soil erosion and its sources and causes, as well as subsequent off-site damage.

  9. Effect of sheet and rill erosion on overland flow connectivity in bare agricultural plots

    NASA Astrophysics Data System (ADS)

    Penuela Fernandez, Andres; Rocio Rodriguez Pleguezuelo, Carmen; Javaux, Mathieu; Bielders, Charles L.

    2014-05-01

    Rill erosion processes generate preferential flow paths that may increase the degree of connectivity of the soil surface and hence strongly modify its hydrological response. However, few studies have tried to quantify the effect of rill development on overland flow connectivity. For this purpose, changes in surface microtopography were monitored on three bare agricultural plots (3 m wide x 10 m long and 11% of slope) in Louvain-la-Neuve (Belgium) under natural rainfall conditions. Digital elevation models of these plots were obtained on a monthly basis over a 1-year period by photogrammetry using the Micmac software. Runoff was collected at the plot outlets. To characterize the hydrological connectivity, a functional connectivity indicator was used, called the relative surface connection function (RSCf). This indicator, which relates the area connected to the outflow boundary to the degree of filling of maximum depression storage (MDS), is fast to compute and was previously shown to be able to capture runoff-relevant connectivity properties. The RSC function was calculated for each DEM and the evolution of overland flow connectivity was quantified and compared to the measured runoff. The results of this study showed that the changes in microtopography resulting from sheet and rill erosion have a strong impact on the hydrological connectivity as reflected in the RSCf. A higher volume of runoff was generated as a consequence of surface sealing and the decrease of the MDS. More rapid runoff initiation was observed as the RSCf evolved from a concave to a convex shape.

  10. An Establishment of Rainfall-induced Soil Erosion Index for the Slope Land in Watershed

    NASA Astrophysics Data System (ADS)

    Tsai, Kuang-Jung; Chen, Yie-Ruey; Hsieh, Shun-Chieh; Shu, Chia-Chun; Chen, Ying-Hui

    2014-05-01

    With more and more concentrated extreme rainfall events as a result of climate change, in Taiwan, mass cover soil erosion occurred frequently and led to sediment related disasters in high intensity precipiton region during typhoons or torrential rain storms. These disasters cause a severely lost to the property, public construction and even the casualty of the resident in the affected areas. Therefore, we collected soil losses by using field investigation data from the upstream of watershed where near speific rivers to explore the soil erosion caused by heavy rainfall under different natural environment. Soil losses induced by rainfall and runoff were obtained from the long-term soil depth measurement of erosion plots, which were established in the field, used to estimate the total volume of soil erosion. Furthermore, the soil erosion index was obtained by referring to natural environment of erosion test plots and the Universal Soil Loss Equation (USLE). All data collected from field were used to compare with the one obtained from laboratory test recommended by the Technical Regulation for Soil and Water Conservation in Taiwan. With MATLAB as a modeling platform, evaluation model for soil erodibility factors was obtained by golden section search method, considering factors contributing to the soil erosion; such as degree of slope, soil texture, slope aspect, the distance far away from water system, topography elevation, and normalized difference vegetation index (NDVI). The distribution map of soil erosion index was developed by this project and used to estimate the rainfall-induced soil losses from erosion plots have been established in the study area since 2008. All results indicated that soil erodibility increases with accumulated rainfall amount regardless of soil characteristics measured in the field. Under the same accumulated rainfall amount, the volume of soil erosion also increases with the degree of slope and soil permeability, but decreases with the

  11. 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

  12. Tillage and water erosion on different landscapes in the northern North American Great Plains evaluated using 137Cs technique and soil erosion models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Total soil erosion is the integrated result of all forms of soil erosion – wind, water, and tillage. The relative contribution of each erosion process varies within different landscapes and within different landform elements. In this study, we investigated the patterns of water and tillage erosion a...

  13. Analysing, quantifying and modelling soil erosion on steep hillslopes in different climatic areas using LiDAR and SFM DEMs

    NASA Astrophysics Data System (ADS)

    Neugirg, Fabian; Haas, Florian; Kaiser, Andreas; Schmidt, Jürgen; Becht, Michael

    2014-05-01

    Soil erosion is a worldwide well known problem and has therefore been subject to various scientific studies, especially on agricultural areas. However soil erosion on steep hillslopes in mountainous drainage basins can be a threat to human infrastructure as it supplies material, e.g. for debris flows to torrents. The study presented here aims to analyse, quantify and model soil erosion on (very) steep hillslopes free of vegetation in different climatic areas ranging from South Germany to Central Italy. Multitemporal digital elevation models were acquired with terrestrial laserscanning and from terrestrial and aerial structure from motion-based imagery. Analysis of erosion is mainly based on slope wash and rill erosion during summer months as well as erosion through freezing and melting processes during winter months in catchments of the Bavarian Alps. Erosional processes in the Mediterranean are mainly controlled by different precipitation regimes throughout the year. Annual erosion and accumulation rates are quantified and used for modelling purposes. First results of the presented project show, that the amount of material eroded is mainly controlled by the size of the sediment contributing area. However there are also other controlling factors, such as slope angle, slope length and vegetation cover which are investigated within this project.

  14. The relevance of wind-driven rain for future soil erosion research

    NASA Astrophysics Data System (ADS)

    Fister, Wolfgang; Marzen, Miriam; Iserloh, Thomas; Seeger, Manuel; Heckrath, Goswin; Greenwood, Philip; Kuhn, Nikolaus J.; Ries, Johannes B.

    2014-05-01

    this PhD-project. By measuring soil erosion rates on the same plot, both with and without wind application, the influence of wind on soil detachment and erosion rates can now clearly be determined. Field experiments with the Portable Wind and Rainfall Simulator, which were carried out in Andalusia (Spain), in Wageningen (The Netherlands), and in Foulum (Denmark) during and within 3 years after finishing the PhD-project, aimed to improve the knowledge of processes involved, and to show the relevance of wind-driven rainfall erosion. The results indicate that the influence of wind depends on the complexity of the landscape. In an environment with homogenous conditions (loose sand mixture) and only a few variable factors (i.e. no vegetation, no surface roughness, no slope), like the test site in Wageningen, the increase of erosion rates due to the influence of wind could be seen in almost every test run. This clear influence of wind decreased with the amount of involved factors from agricultural soils in Denmark with a homogenous sandy texture and steep slopes, to highly degraded abandoned/fallow land with thick soil crusts and a clay-silt texture in Andalusia. The results obtained by "simple" rainfall simulations, therefore, clearly underestimate soil erosion rates, depending on the environment. This could, in our opinion, have strong implications for future soil erosion research and modelling.

  15. Human induced prehistoric and historical soil erosion and landscape development in Southwestern USA

    NASA Astrophysics Data System (ADS)

    Dotterweich, Markus; Ivester, Andrew H.; Hanson, Paul R.; Daniel, Larsen; Dye, David H.; Foster, Thomas H., II

    2015-04-01

    The significance of soil erosion due to pre-historic land use and possible feedback mechanisms had been hardly recognized in the Southeastern USA. Here, the agricultural practices only began in the second half of the Holocene. Sedentary hunters and gatherers started to domesticate squash and sunflowers. Associated with the expansion of maize cultivation in the Mississippian period between AD 800 and 1100, significant forest clearings took place on the river floodplains. During this time, central settlements with up to 30,000 residences existed and the surrounding ridge and furrow fields extended to up to 30 ha. It is still open to question why these groups already declined in the 14/15th centuries already before the arrival of the Europeans. However, around AD 1540 the conquistador de Soto still reports extended fields with intensive cultivation of maize in the uplands of Northern Mississippi. Despite of this intensive land use by Native Americans, current research gives no indication that these activities had any significant impact on river channel form. Also, no clear evidence exists for distinct channel change occurring in response to any sort of middle Holocene Hypsithermal, Medieval warm period, or the Little Ice Age. We will present results of a project which aims to explore erosion forms, colluvial sediments and buried soils in selected 0-order and 1st-order watersheds in the southeastern USA in order to gain, solidify, and evaluate general data on soil erosion during the Native American land use period and its respective long-term effects on the environment. This will be achieved by 1) recording the stratigraphy of colluvial and alluvial sediments and buried soils, 2) mapping the extent of erosional and colluvial forms, 3) analyzing chemical and physical soil and sediment properties, 4) establishing chronological control using various dating techniques including radiocarbon and OSL dating, and 5) quantifying soil erosion using hillslope sediments. The

  16. 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

  17. Lateral Transport of Black vs. Bulk SOM with soil erosion

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    Erosion of topsoil, and associated bulk soil organic matter (SOM) and black carbon (BC) impose significant controls on dynamics of SOM within the eroding watershed. As of yet, the relative lateral distribution and export of bulk SOM vs. BC from eroding upland, fire-affected forested ecosystems has been poorly quantified. The extent of both bulk and BC export from eroding watersheds depends on SOM concentration, composition and stability in eroding slope profiles, the type and rate of erosion, and time since and severity of past fires. Sediment traps located at the point where first-order streams leave the watershed provide insight into the amount and composition of material removed by soil erosion. Here, we will present data on the amount and composition of soil material eroded from eight first-order watersheds in the mixed-conifer zone of the Sierra National Forest in the Kings River Experimental Watershed. Our results show that there is large variability in nature of exported material - including ratio of bulk sediment vs. BC content, chemical composition of SOM, and overall sediment export across the watersheds that is not directly related to watershed size or climatic variability.

  18. Integrating Phosphorus Movement with Soil and Water Loss in the Daily Erosion Project

    NASA Astrophysics Data System (ADS)

    Sklenar, Tim; Perez-Bidegain, Mario; Cruse, Richard; Gelder, Brian; Herzmann, Daryl

    2016-04-01

    The Daily Erosion Project (DEP) is an ongoing modelling effort which is now in its second generation. DEP provides comprehensive and dynamic estimates of sediment delivery, soil erosion, and hill slope runoff for agricultural land areas across the Midwestern United States every day for Hydrologic Unit Code 12 (HUC 12) size watersheds. Results are posted every morning on the Internet at dailyerosion.org. Currently DEP covers all of Iowa and portions of Kansas and Minnesota, but expansion of coverage is ongoing. The integration of highly resolute spatial and temporal climate data, soil properties, crop rotation and residue management data affords the opportunity to test the effects of using multiple conservation practices on the transport and fate of water borne nutrients, especially phosphorus, on the Midwestern United States agricultural landscapes. Understanding the interaction of different environmental and land management practices on phosphorus movement will allow data from the DEP to guide conservation efforts as expansion continues into surrounding Midwestern states. The presentation will provide an overview of the DEP technology, including how input data are derived and used to make daily erosion estimates on over 200,000 flowpaths in the modelling area, as well as a discussion of the ongoing phosphorus transport modelling efforts and plans for future expansion (both land area and model functionality).

  19. Intensive agriculture reduces soil biodiversity across Europe.

    PubMed

    Tsiafouli, Maria A; Thébault, Elisa; Sgardelis, Stefanos P; de Ruiter, Peter C; van der Putten, Wim H; Birkhofer, Klaus; Hemerik, Lia; de Vries, Franciska T; Bardgett, Richard D; Brady, Mark Vincent; Bjornlund, Lisa; Jørgensen, Helene Bracht; Christensen, Sören; Hertefeldt, Tina D'; Hotes, Stefan; Gera Hol, W H; Frouz, Jan; Liiri, Mira; Mortimer, Simon R; Setälä, Heikki; Tzanopoulos, Joseph; Uteseny, Karoline; Pižl, Václav; Stary, Josef; Wolters, Volkmar; Hedlund, Katarina

    2015-02-01

    Soil biodiversity plays a key role in regulating the processes that underpin the delivery of ecosystem goods and services in terrestrial ecosystems. Agricultural intensification is known to change the diversity of individual groups of soil biota, but less is known about how intensification affects biodiversity of the soil food web as a whole, and whether or not these effects may be generalized across regions. We examined biodiversity in soil food webs from grasslands, extensive, and intensive rotations in four agricultural regions across Europe: in Sweden, the UK, the Czech Republic and Greece. Effects of land-use intensity were quantified based on structure and diversity among functional groups in the soil food web, as well as on community-weighted mean body mass of soil fauna. We also elucidate land-use intensity effects on diversity of taxonomic units within taxonomic groups of soil fauna. We found that between regions soil food web diversity measures were variable, but that increasing land-use intensity caused highly consistent responses. In particular, land-use intensification reduced the complexity in the soil food webs, as well as the community-weighted mean body mass of soil fauna. In all regions across Europe, species richness of earthworms, Collembolans, and oribatid mites was negatively affected by increased land-use intensity. The taxonomic distinctness, which is a measure of taxonomic relatedness of species in a community that is independent of species richness, was also reduced by land-use intensification. We conclude that intensive agriculture reduces soil biodiversity, making soil food webs less diverse and composed of smaller bodied organisms. Land-use intensification results in fewer functional groups of soil biota with fewer and taxonomically more closely related species. We discuss how these changes in soil biodiversity due to land-use intensification may threaten the functioning of soil in agricultural production systems.

  20. 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

  1. 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...

  2. 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...

  3. 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...

  4. 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

    ... computer model that predicts soil erosion via simulation of the fundamental processes controlling wind erosion. WEPS can calculate soil movement, estimate plant damage, and predict PM-10 emissions when wind... Natural Resources Conservation Service Notice of Implementation of the Wind Erosion Prediction System...

  5. An Economic Analysis of USDA Erosion Control Programs: A New Perspective. Agricultural Economic Report No. 560.

    ERIC Educational Resources Information Center

    Strohbehn, Roger, Ed.

    A study analyzed the total (public and private) economic costs and benefits of three U.S. Department of Agriculture erosion control programs. These were the Conservation Technical Assistance Program, Great Plains Conservation Program, and Agricultural Conservation Program. Significant efforts at funding for current programs were directed to…

  6. 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.

  7. Evaluation of a model framework to estimate soil and soil organic carbon redistribution by water and tillage using 137Cs in two U.S Midwest agricultural fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated lands in the U.S. Midwest have been affected by soil erosion causing environmental and agricultural problems, including the redistribution of soil organic carbon (SOC) in the landscape. However, the importance of SOC redistribution on soil productivity and crop yield is still uncertain. I...

  8. World population growth, soil erosion, and food security. [Adapted from book

    SciTech Connect

    Brown, L.R.

    1981-11-27

    Since 1950, world food output has more than doubled, but in many cases this impressive gain has been achieved by the adoption of agricultural practices that lead to an excessive rate of soil erosion. At least one-fifth, and perhaps as much as one-third, of the global cropland base is losing soil at a rate that is undermining its long-term productivity. World food production per person will eventually begin to decrease if the loss of topsoil continues at current rates. In view of this, there is an urgent need to realign national priorities everywhere in order to get the brakes on world population growth and to finance the adoption of agricultural practices that will preserve the cropland base. (Ed. note: this article was adapted from Mr. Brown's recent book, Building a Sustainable Society (Norton, New York, 1981)). 46 references, 5 tables.

  9. Assessing different agricultural managements with the use of soil quality indices in a Mediteranean calcareous soil

    NASA Astrophysics Data System (ADS)

    Morugán-Coronado, Alicia; García-Orenes, Fuensanta; Mataix-Solera, Jorge; Arcenegui, Vicky; Cerdà, Artemi

    2013-04-01

    Soil erosion is a major problem in the Mediterranean region due to the arid conditions and torrential rainfalls, which contribute to the degradation of agricultural land. New strategies must be developed to reduce soil losses and recover or maintain soil functionality in order to achieve a sustainable agriculture. An experiment was designed to evaluate the effect of different agricultural management on soil properties and soil quality. Ten different treatments (contact herbicide, systemic herbicide, ploughing, Oat mulch non-plough, Oats mulch plough, leguminous plant, straw rice mulch, chipped pruned branches, residual-herbicide and agro geo-textile, and three control plots including no tillage or control and long agricultural abandonment (shrub on marls and shrub on limestone) were established in 'El Teularet experimental station' located in the Sierra de Enguera (Valencia, Spain). The soil is a Typic Xerorthent developed over Cretaceous marls in an old agricultural terrace. The agricultural management can modify the soil equilibrium and affect its quality. In this work two soil quality indices (models) developed by Zornoza et al. (2007) are used to evaluate the effects of the different agricultural management along 4 years. The models were developed studying different soil properties in undisturbed forest soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. Model 1, that explained 92% of the variance in soil organic carbon (SOC) showed that the SOC can be calculated by the linear combination of 6 physical, chemical and biochemical properties (acid phosphatase, water holding capacity (WHC), electrical conductivity (EC), available phosphorus (P), cation exchange capacity (CEC) and aggregate stability (AS). Model 2 explains 89% of the SOC variance, which can be calculated by means of 7 chemical and biochemical properties (urease, phosphatase, and ß-glucosidase activities, pH, EC, P and CEC). We use the

  10. Assessing different agricultural managements with the use of soil quality indices in a Mediteranean calcareous soil

    NASA Astrophysics Data System (ADS)

    Morugán-Coronado, Alicia; García-Orenes, Fuensanta; Mataix-Solera, Jorge; Arcenegui, Vicky; Cerdà, Artemi

    2013-04-01

    Soil erosion is a major problem in the Mediterranean region due to the arid conditions and torrential rainfalls, which contribute to the degradation of agricultural land. New strategies must be developed to reduce soil losses and recover or maintain soil functionality in order to achieve a sustainable agriculture. An experiment was designed to evaluate the effect of different agricultural management on soil properties and soil quality. Ten different treatments (contact herbicide, systemic herbicide, ploughing, Oat mulch non-plough, Oats mulch plough, leguminous plant, straw rice mulch, chipped pruned branches, residual-herbicide and agro geo-textile, and three control plots including no tillage or control and long agricultural abandonment (shrub on marls and shrub on limestone) were established in 'El Teularet experimental station' located in the Sierra de Enguera (Valencia, Spain). The soil is a Typic Xerorthent developed over Cretaceous marls in an old agricultural terrace. The agricultural management can modify the soil equilibrium and affect its quality. In this work two soil quality indices (models) developed by Zornoza et al. (2007) are used to evaluate the effects of the different agricultural management along 4 years. The models were developed studying different soil properties in undisturbed forest soils in SE Spain, and the relationships between soil parameters were established using multiple linear regressions. Model 1, that explained 92% of the variance in soil organic carbon (SOC) showed that the SOC can be calculated by the linear combination of 6 physical, chemical and biochemical properties (acid phosphatase, water holding capacity (WHC), electrical conductivity (EC), available phosphorus (P), cation exchange capacity (CEC) and aggregate stability (AS). Model 2 explains 89% of the SOC variance, which can be calculated by means of 7 chemical and biochemical properties (urease, phosphatase, and ß-glucosidase activities, pH, EC, P and CEC). We use the

  11. Australian net (1950s-1990) soil organic carbon erosion is an omitted CO2 source

    NASA Astrophysics Data System (ADS)

    Chappell, A.; Webb, N.; Viscarra Rossel, R. A.; Bui, E. N.

    2013-12-01

    The debate about agricultural erosion substantially offsetting fossil fuel emissions and acting as an important source or sink of CO2 is informed by studies of water and tillage erosion at the field scale and extrapolated across regions based on gross erosion. We use ';catchment' scale (~25 km2) estimates of 137Cs-derived net (1950s-1990) soil redistribution of all processes (wind, water and tillage) to calculate the soil organic carbon (SOC) net redistribution across Australia. We include the selective removal of SOC at net eroding locations, SOC enrichment of transported sediment and net depositional locations. We show that the total SOC net redistribution for Australia is -4.06 Tg SOC y-1, a net loss of SOC from the terrestrial ecosystem and 2% of the total carbon stock (0-10 cm) of Australia. Assuming the SOC is mineralised, these losses represent 12% of CO2-e emissions from all carbon pools in Australia and a significant source of uncertainty in the carbon budget SOC net redistribution as a proportion (%) of SOC stocks Calculation of soil organic carbon net (1950s-1990) redistribution and its proportion for land use classes across Australia *Using an equal area projection the area of a pixel is approximately 4.53 km x 4.87 km ≈ 22.03 km2 equivalent to 2203 ha

  12. Quantitative Measurement of Soil Erosion from Tls and Uav Data

    NASA Astrophysics Data System (ADS)

    Eltner, A.; Mulsow, C.; Maas, H.-G.

    2013-08-01

    Soil erosion is a major issue concerning crop land degradation. Understanding these complex erosion processes is necessary for effective soil conservation. Herein, high resolution modelling of relief changes caused by run-off from precipitation events is an essential research matter. For non-invasive field measurements the combination of unmanned airborne vehicle (UAV) image data and terrestrial laser scanning (TLS) may be especially suitable. The study's objective is to measure high precision digital terrain models (DTM) of the soil surface at two selected research areas with the extent of at least 500 square meters. The used UAV is integrated with GPS and inertial measurement unit (IMU). Furthermore, an active stabilizing camera mount equipped with a customary compact camera is implemented. For multi-temporal comparison of measured soil surfaces and for aligning UAV and TLS data a stable local reference system consisting of signalized points is defined by total station measurements. Two different software packages are applied for DTM generation from UAV images and compared to the corresponding DTM captured by TLS. Differences between the point clouds are minimal six millimeters and generally within TLS accuracy range. First multi-temporal comparisons are made and illustrate interesting surface changes.

  13. [Dynamics of soil erosion at upper reaches of Minjiang River based on GIS].

    PubMed

    He, Xingyuan; Hu, Zhibi; Li, Yuehui; Hu, Yuanman

    2005-12-01

    Based on TM and ETM imagines, and employing GIS technique and empirical Revised Universal Soil Loss Equation (RUSLE) model, this paper studied the dynamics of soil erosion at the upper reaches of Minjiang River during three typical periods, with the main affecting factors analyzed. The results showed that the soil erosion area was increased by 1.28%, 1.84 % and 1.70% in 1986, 1995 and 2000, respectively. The average erosion modulus was increased from 832.64 t x km(-2) x yr(-1) in 1986 to 1048.74 t x km(-2) yr(-2) in 1995 and reached 1362.11 t x km(-2) yr(-1) in 2000, and soil loss was mainly of slight and light erosion, companying with a small quantity of middling erosion. The area of soil erosion was small, and the degree was light. There was a significant correlation between slope and soil loss, which mainly happened in the regions with a slope larger than 25 degrees, and accounted for 93.65%, 93.81% and 92.71% of the total erosion in 1986, 1995 and 2000, respectively. As for the altitude, middling, semi-high and high mountains and dry valley were liable to soil erosion, which accounted for 98.21%, 97.63% and 99.27% of the total erosion in 1986, 1995 and 2000, respectively. Different vegetation had a significant effect on soil erosion, and shrub and newly restored forest were the main erosion area. Excessive depasture not only resulted in the degradation of pasture, but also led to slight soil erosion. Land use type and soil type also contributed to soil loss, among which, dry-cinnamon soil and calcic gray-cinnamon soil were the most dangerous ones needing more protection. Soil loss was also linearly increased with increasing population and households, which suggested that the increase of population and households was the driving factor for soil loss increase in this area.

  14. 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

  15. 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

  16. 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 content of the topsoil layers were dominantly affected by evapotranspiration (which apparently depended on aspect of the slope) and secondary by soil properties change due to soil erosion especially on steep slopes. Both transects in Brumovice a one transect in Vidim were located on north-facing slopes, while one transect in Vidim was located on south-facing slope. As result higher soil water contents were observed at the steepest part of all 3 transects (north aspects). We found strong significant relationship between slope and average soil moisture for both transects in Brumovice. In the case of the south-facing transect no apparent trend of soil water content with respect to terrain position was observed. Acknowledgment: Authors acknowledge the financial support of the Ministry of Agriculture of the Czech Republic (grant No. QJ1230319).

  17. [Assessment of the impacts of soil erosion on water environment based on the integration of soil erosion process and landscape pattern].

    PubMed

    Liu, Yu; Wu, Bing-Fang; Zeng, Yuan; Zhang, Lei

    2013-09-01

    The integration of the effects of landscape pattern to the assessment of the impacts of soil erosion on eco-environmental is of practical significance in methodological prospect, being able to provide an approach for identifying water body's sediment source area, assessing the potential risks of sediment export of on-site soil erosion to the target water body, and evaluating the capacity of regional landscape pattern in preventing soil loss. In this paper, the RUSLE model was applied to simulate the on-site soil erosion rate. With the consideration of the soil retention potential of vegetation cover and topography, a quantitative assessment was conducted on the impacts of soil erosion in the water source region of the middle route for South-to-North Water Transfer Project on rivers and reservoirs by delineating landscape pattern at point (or cell) scale and sub-watershed level. At point (or grid cell) scale, the index of soil erosion impact intensity (I) was developed as an indicator of the potential risk of sediment export to the water bodies. At sub-watershed level, the landscape leakiness index (LI) was employed to indicate the sediment retention capacity of a given landscape pattern. The results revealed that integrating the information of landscape pattern and the indices of soil erosion process could spatially effectively reflect the impact intensity of in situ soil erosion on water bodies. The LI was significantly exponentially correlated to the mean sediment retention capacity of landscape and the mean vegetation coverage of watershed, and the sediment yield at sub-watershed scale was significantly correlated to the LI in an exponential regression. It could be concluded that the approach of delineating landscape pattern based on soil erosion process and the integration of the information of landscape pattern with its soil retention potential could provide a new approach for the risk evaluation of soil erosion.

  18. 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

  19. Using remote sensing for volumetric analyses of soil degradation by erosion

    NASA Astrophysics Data System (ADS)

    Vlacilova, Marketa; Krasa, Josef; Kavka, Petr

    2014-05-01

    least one representative square plot in each section was created. Next, the volume of erosion rills in each square plot was calculated and corrected by referenced relation. These results were extrapolated to the whole of the study catchment. The study contains volumetric evaluation of actual soil loss by rill erosion in detailed scale and in addition, there is a model for rill volume evaluation in highly detached fields. The results illustrate that the volume of soil loss can reach extreme values in detached areas after only one intensive rainfall event. Hundreds of cubic metres of soil can be transported in rills and ephemeral gullies from a single hectare of arable land. Findings are useful for development and verification of procedures for the identification and evaluation of actual degradation of agricultural land by water erosion. The research has been supported by the project No. QJ330118 "Using Remote Sensing for Monitoring of Soil Degradation by Erosion and Erosion Effects".

  20. Soil erosion evaluation in a rapidly urbanizing city (Shenzhen, China) and implementation of spatial land-use optimization.

    PubMed

    Zhang, Wenting; Huang, Bo

    2015-03-01

    Soil erosion has become a pressing environmental concern worldwide. In addition to such natural factors as slope, rainfall, vegetation cover, and soil characteristics, land-use changes-a direct reflection of human activities-also exert a huge influence on soil erosion. In recent years, such dramatic changes, in conjunction with the increasing trend toward urbanization worldwide, have led to severe soil erosion. Against this backdrop, geographic information system-assisted research on the effects of land-use changes on soil erosion has become increasingly common, producing a number of meaningful results. In most of these studies, however, even when the spatial and temporal effects of land-use changes are evaluated, knowledge of how the resulting data can be used to formulate sound land-use plans is generally lacking. At the same time, land-use decisions are driven by social, environmental, and economic factors and thus cannot be made solely with the goal of controlling soil erosion. To address these issues, a genetic algorithm (GA)-based multi-objective optimization (MOO) approach has been proposed to find a balance among various land-use objectives, including soil erosion control, to achieve sound land-use plans. GA-based MOO offers decision-makers and land-use planners a set of Pareto-optimal solutions from which to choose. Shenzhen, a fast-developing Chinese city that has long suffered from severe soil erosion, is selected as a case study area to validate the efficacy of the GA-based MOO approach for controlling soil erosion. Based on the MOO results, three multiple land-use objectives are proposed for Shenzhen: (1) to minimize soil erosion, (2) to minimize the incompatibility of neighboring land-use types, and (3) to minimize the cost of changes to the status quo. In addition to these land-use objectives, several constraints are also defined: (1) the provision of sufficient built-up land to accommodate a growing population, (2) restrictions on the development of

  1. 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.

  2. Quantification and site-specification of the support practice factor when mapping soil erosion risk associated with olive plantations in the Mediterranean island of Crete.

    PubMed

    Karydas, Christos G; Sekuloska, Tijana; Silleos, Georgios N

    2009-02-01

    Due to inappropriate agricultural management practices, soil erosion is becoming one of the most dangerous forms of soil degradation in many olive farming areas in the Mediterranean region, leading to significant decrease of soil fertility and yield. In order to prevent further soil degradation, proper measures are necessary to be locally implemented. In this perspective, an increase in the spatial accuracy of remote sensing datasets and advanced image analysis are significant tools necessary and efficient for mapping soil erosion risk on a fine scale. In this study, the Revised Universal Soil Loss Equation (RUSLE) was implemented in the spatial domain using GIS, while a very high resolution satellite image, namely a QuickBird image, was used for deriving cover management (C) and support practice (P) factors, in order to map the risk of soil erosion in Kolymvari, a typical olive farming area in the island of Crete, Greece. The results comprised a risk map of soil erosion when P factor was taken uniform (conventional approach) and a risk map when P factor was quantified site-specifically using object-oriented image analysis. The results showed that the QuickBird image was necessary in order to achieve site-specificity of the P factor and therefore to support fine scale mapping of soil erosion risk in an olive cultivation area, such as the one of Kolymvari in Crete. Increasing the accuracy of the QB image classification will further improve the resulted soil erosion mapping.

  3. Assessment of Holocene soil erosion rates on the loess plateau in East Poland using sedimentary archives from closed depressions

    NASA Astrophysics Data System (ADS)

    Kołodyńska-Gawrysiak, Renata; Poesen, Jean; Gawrysiak, Leszek

    2016-04-01

    Closed depressions (CDs) are typical geomorphological features of the European loess belt. They are closed sedimentation basins that enable the estimation of long-term soil erosion rates for different land use environments. This study was conducted in eastern Poland (Nałęczów Plateau). In this region CDs are rather small landforms and the area of 70% of all CDs does not exceed 1500 m2. The study objective was to assess Holocene soil erosion rates in the loess plateau based on a quantitative analysis of colluvial sediments deposited in CDs. Two representative CDs were selected for this study: one CD is located in an old (long-term) forest and the other is situated in a long-term agricultural land. The maximum depth of the CD in the forest, the mean slope gradient and area of the corresponding catchment are 4.9 m, 3.410 and 7568 m² respectively. For the CD in agricultural land these values are 3.2 m, 2.760 and 5156 m² respectively. In both CDs several dozen of drillings and two trenches (2 m long, 1m wide, 2 m deep) were made in the deepest point of the CDs. Mean long-term soil erosion rates were calculated based on the stratigraphy of the soil-sediment sequence infilling the CDs. C-14 and OSL datings of soils and colluvial sediments within the CDs were obtained. For the long-term agricultural used catchment of the CD it was calculated that since 6.31 ± 0.35 ka BP the mean annual soil loss due to water and tillage erosion is 0.63-0.7 t/ha/year or 279.3 mm. In the prehistoric period since 6.31 ± 0.35 ka BP until 1026-1162 AD the mean annual soil erosion rate amounted to 0,10-0.11 t/ha/year or 41.5 mm. During the last ca. 1000 years mean soil erosion rates increased to 3.99-4.63 t/ha/year or 249.2 mm. Results of long-term soil erosion rates (calculated using colluvial sediment sequences in CDs) from agricultural catchments in the loess regions of eastern Poland (this study) and Central Belgium (Gillijns et al. 2005) are quite similar. For the forested catchment

  4. 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...

  5. 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

    Long-term data have been collected by IMAMOTER-CNR from field-scale vineyard plots within the Tenuta Cannona Vine and Wine Experimental Centre of Regione Piemonte, which is located in a valuable vine production area in north-western Italy. Since 2000, runoff and soil erosion monitoring has been carried out under natural rainfall conditions on three parallel field plots (75 m long and 16,5 m wide, slope gradient about 15%) that are conducted with different inter-rows soil management techniques (conventional tillage, reduced tillage, controlled grass cover). Experimental plots are part of a 16-hectars experimental vineyard, managed in according to conventional farming for wine production. Recurrent surveys have been carried out in the runoff plots to investigate spatial and temporal variability of the soil bulk density, soil moisture and penetration resistance. The primary intent of the program was to evaluate the effects of agricultural management practices and tractor traffic on the hydrologic, soil erosion and soil compaction processes in vineyard. The Cannona Data Base (CDB) represents a data collection which is unique in Italy, showing the response of soil to rainfall in terms of runoff and soil erosion over more than a decade. It includes data for more than 200 runoff events and over 70 soil loss events; moreover, periodic measurements for soil physical characteristics are included for the three plots. The CDB can now be accessed via a website supported by the CNR, that is addressed to water and land management researchers and professionals. The CDB is currently used to calibrate a model for runoff and soil erosion prediction in vineyard environment. The CDB website includes a descriptive and informative section, which contains results of over than 10 years of experimental activity, reports and presentations, addressed to enhance the awareness of citizens and stakeholders about land degradation processes and about impacts of different soil management practices

  6. 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.

  7. The environmental behaviour of beryllium-7; implications for its use as a soil erosion tracer

    NASA Astrophysics Data System (ADS)

    Taylor, A.; Blake, W. H.; Keith-Roach, M. J.; Couldrick, L.

    2010-05-01

    Beryllium-7 is a cosmogenic fallout radionuclide (FRN) that can be employed as a tracer in soil erosion studies. Owing to its short half-life (53.3 days), estimates of soil redistribution from a single event or wet season can be derived, complimenting medium-term 137Cs-based data. The ability of 7Be to provide robust quantification of soil erosion over short timescales is vital when considering the potential for climate change to influence precipitation patterns and shifts in landuse. A major requirement of the technique is the capacity of the FRN to adsorb to soil particles and remain bound during transport. To date, little attention has been given to the geochemical behaviour of 7Be. The research reported here aims to develop knowledge of 7Be adsorption behaviour in a range of soil types and environmental conditions to support its use as a tracer at the catchment-scale. Four agricultural soils common to south Devon, UK were selected for experiments designed to investigate7Be solid-phase partitioning in soils and tracer stability under changing environmental conditions. Preliminary results from two key aspects of the work are presented here. The BCR three-step sequential extraction procedure was adopted to determine 7Be adsorption to operationally-defined soil fractions. Early findings indicate that 7Be is largely associated with Fe/Mn fractions with up to 67% adsorbed to this reducible phase. This supports the use of 7Be as a soil erosion tracer at the slope-scale but may have implications for 7Be mobility under reducing conditions in deposition zones. In addition, batch experiments have been undertaken to evaluate 7Be behaviour in the dissolved phase focussing upon the role of DOC as a complexing agent in soil solutions since soil solution DOC can increase following manure and compost application. Results will underpin the use of 7Be as a sediment tracer within an Interreg IVA funded research programme addressing wetland restoration as a catchment management

  8. The environmental behaviour of beryllium-7: implications for its use as a soil erosion tracer

    NASA Astrophysics Data System (ADS)

    Taylor, A.; Blake, W. H.; Keith-Roach, M. J.; Couldrick, L.

    2010-05-01

    Beryllium-7 is a cosmogenic fallout radionuclide (FRN) that can be employed as a tracer in soil erosion studies. Owing to its short half life (53.3 days), estimates of soil redistribution from a single event or wet season can be derived, complimenting medium-term 137Cs-based data. The ability of 7Be to provide robust quantification of soil erosion over short timescales is vital when considering the potential for climate change to influence precipitation patterns and shifts in landuse. A major requirement of the technique is the capacity of the FRN to adsorb to soil particles and remain bound during transport. To date, little attention has been given to the geochemical behaviour of 7Be. The research reported here aims to develop knowledge of 7Be adsorption behaviour in a range of soil types and environmental conditions to support its use as a tracer at the catchment scale. Four agricultural soils common to south Devon, UK were selected for experiments designed to investigate7Be solid-phase partitioning in soils and tracer stability under changing environmental conditions. Preliminary results from two key aspects of the work are reported here. The BCR three-step sequential extraction procedure was adopted to investigate 7Be adsorption to operationally-defined soil fractions. Early findings indicate that 7Be is largely associated with Fe/Mn fractions with up to 67% adsorbed to this reducible phase. This supports the use of 7Be as a soil erosion tracer at the slope-scale but may have implications for 7Be mobility under reducing conditions in deposition zones. In addition, batch experiments have been undertaken to evaluate 7Be behaviour in the dissolved phase focusing upon the role of DOC as a complexing agent in soil solutions since soil solution DOC can increase following manure and compost application. Results will be used to underpin the application of 7Be as a sediment tracer within an Interreg IVA funded research programme addressing wetland restoration as a

  9. 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

  10. 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

  11. Post-fire soil erosion on vineyards and canary pine-stands on the subtropical island of La Palma: scope of application of TLS?

    NASA Astrophysics Data System (ADS)

    Umstaedter, Kathrin; Haas, Florian; Becht, Michael

    2013-04-01

    Land use is considered as a main factor regarding post-fire soil erosion. Especially in the subtropical climate with extreme rainfall events in winter and drought periods during summer times, soil erosion can clearly exceed the soil reproduction rate. On the Canary Island of La Palma frequent wildfires and steep slopes contribute to a high likelihood of post-fire soil erosion. For a quantitative measurement of the erosion rate a terrestrial Laser Scanner with high resolution in combination with a dGPS is used. The main target of this study is to quantify the post-fire soil erosion rates on study sites with a different land use on the island of La Palma (Canary Islands). The investigation focuses on two land use forms; both are very common and widespread on the island: canary pine stands and vineyard areas. The study sites are characterized by a varying steepness, a different fire history (wildfires in 2000, 2009 and 2012) and different stages of soil development. Both denudation and gully erosion processes are spread over the sites. Intense precipitation events can trigger debris flows and extensive soil erosion on post-fire sites, like in the year 2009 in the south or in 2012 on the west and east side of La Palma. Regarding that, erosion is not just a problem for agriculture, but for the infrastructure. For our project we assume, that different topography, different land use and different forest fire history can result in a different soil erosion rate and type (gully incision, denudation processes). To calculate the post-fire erosion rates of the two land use forms, 24 study sites - 10 sites in vineyard areas, 14 in canary pines stands - were selected. By means of a 3D terrestrial Laser Scanner (Riegl LMS Z420i), high resolution digital terrain models of the study sites were compiled. The data acquisition was carried out in October 2011, May 2012 and December 2012 and subsequently the terrain models were compared. With this method not only erosion rates can be

  12. Use of 137Cs measurements to estimate changes in soil erosion rates associated with changes in soil management practices on cultivated land.

    PubMed

    Schuller, P; Walling, D E; Sepúlveda, A; Trumper, R E; Rouanet, J L; Pino, I; Castillo, A

    2004-05-01

    Intensification of agricultural production in south-central Chile since the 1970s has caused problems of increased soil erosion and associated soil degradation. These problems have prompted a shift from conventional tillage to no-till management practices. Faced with the need to establish the impact of this shift in soil management on rates of soil loss, the use of caesium-137 (137Cs) measurements has been explored. A novel procedure for using measurements of the 137Cs depth distribution to estimate rates of soil loss at a sampling point under the original conventional tillage and after the shift to no-till management has been developed. This procedure has been successfully applied to a study site at Buenos Aires farm near Carahue in the 9th region of Chile. The results obtained indicate that the shift from conventional tillage to no-till management has caused net rates of soil loss to decrease to about 40% of those existing under conventional tillage. This assessment of the impact of introducing no-till management at the study site must, however, be seen as provisional, since only a limited number of sampling points were used. A simplified procedure aimed at documenting the reduction in erosion rates at additional sampling points, based solely on measurements of the 137Cs inventory of bulk cores and the 137Cs activity in the upper part of the soil has been developed and successfully tested at the study site. Previous application of 137Cs measurements to estimate erosion rates has been limited to estimation of medium-term erosion rates during the period extending from the beginning of fallout receipt to the time of sampling. The procedures described in this paper, which permits estimation of the change in erosion rates associated with a shift in land management practices, must be seen as representing a novel application of 137Cs measurements in soil erosion investigations.

  13. Sediment budget for Murder Creek, Georgia, USA, from Pu239+240 - determined soil erosion rates

    NASA Astrophysics Data System (ADS)

    Stubblefield, A. P.; Matissoff, G.; Ketterer, M. E.; Whiting, P. J.

    2005-12-01

    Soil inventories of the radionuclides Cs137 and Pb210 have been used in a variety of environments as indicators for erosion and depositional processes. Development of sediment budgets for entire watersheds from radionuclide data has been somewhat constrained because limited sample numbers may not adequately characterize the wide range of geomorphic conditions and land uses found in heterogeneous environments. The measurement of Pu239+240 shows great potential for developing quantitative watershed sediment budgets. With inductively-coupled plasma mass spectrometry, hundreds of samples may be processed in dramatically shorter times than the gamma spectrometry method used for Cs137 or alpha spectrometry method used for Pb210. We collected surface soil samples from Murder Creek in the Piedmont region of Georgia, USA, to compare Pu239+240 inventories with Cs137 and Pb210 inventories for a range of land uses in a predominantly forested watershed. Excellent correlations were found for radionuclide inventories (r2 =0.88, n = 38) and high resolution (4 mm) depth profiles. The second objective was to generate a sediment budget using the full Pu239+240 dataset (n = 309). Average Pu239+240 inventories were 70.0 Bq/m2 for hardwood forest, 60.0 Bq/m2 for pine plantation, 65.1 Bq/m2 for pine forest, 66.7 Bq/m2 for row crop agriculture and 67.9 Bq/m2 for pasture. The sediment budget will be constructed by converting inventories into site-specific erosion rates. Erosion rates will be scaled up to the watershed scale using GIS coverages of land use, soil, slope, and slope position. Results will be compared with Murder Creek sediment budgets in the scientific literature generated from RUSLE erosion modeling, USGS monitoring networks and reservoir sedimentation.

  14. 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

  15. 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.

  16. Engineering Biochar Hydrophobicity to Mitigate Risk of Top-Soil Erosion

    NASA Astrophysics Data System (ADS)

    Kinney, T. J.; Dean, M. R.; Hockaday, W. C.; Masiello, C. A.

    2009-12-01

    The pyrolysis of biomass is a net carbon negative method of sequestering atmospheric carbon as recalcitrant black carbon. The resulting solid product, called biochar, is likely to improve agricultural soils when used as a soil conditioner in sustainable land management practice. Biochar has been shown to improve crop yields, improve water-holding capacity in sandy soils, increase cation exchange capacity (CEC), and retain nutrients from fertilization longer than soils unamended with biochar. Biochar undoubtedly has high potential as both a carbon management tool and a tool to increase global food production. However, little is understood about possible side effects of biochar in agricultural soils such as ecosystem toxicity, interactions with biota, and modification of soil hydrologic properties, such as permeability. The hydrophobicity of a soil determines how easily precipitation can permeate soil pores. Water that fails to permeate is redirected as runoff, responsible for the detachment and transport of nutrient-rich topsoil particles. Mitigating top-soil erosion is an important aspect of sustainable land management. Biochar, primarily composed of condensed aromatic structures, is a hydrophobic material and incorporating it into agricultural soils may act to alter soil hydrology through multiple avenues. These include a likely increase in soil water-holding capacity (a positive outcome) and a potential increase in soil hydrophobicity (a negative outcome). In an effort to understand how to engineer reduced biochar hydrophobicity, we investigated the hydrophobicity of biochars as a function of biomass feedstock, pyrolysis temperatures, and post-pyrolysis chemical treatments. We used Water Drop Penetration Time (WDPT) and Molarity of an Ethanol Drop (MED) tests to measure hydrophobicity, and FTIR, CPMAS-NMR, and N2-BET to probe the surface chemistry, bulk chemistry, and surface area of various biochars, respectively. We used post-pyrolysis chemical treatments of

  17. Comparison of 1D and 2D modelling with soil erosion model SMODERP

    NASA Astrophysics Data System (ADS)

    Kavka, Petr; Weyskrabova, Lenka; Zajicek, Jan

    2013-04-01

    The contribution presents a comparison of a runoff simulated by profile method (1D) and spatially distributed method (2D). Simulation model SMODERP is used for calculation and prediction of soil erosion and surface runoff from agricultural land. SMODERP is physically based model that includes the processes of infiltration (Phillips equation), surface runoff (kinematic wave based equation), surface retention, surface roughness and vegetation impact on runoff. 1D model was developed in past, new 2D model was developed in last two years. The model is being developed at the Department of Irrigation, Drainage and Landscape Engineering, Civil Engineering Faculty, CTU in Prague. 2D model was developed as a tool for widespread GIS software ArcGIS. The physical relations were implemented through Python script. This script uses ArcGIS system tools for raster and vectors treatment of the inputs. Flow direction is calculated by Steepest Descent algorithm in the preliminary version of 2D model. More advanced multiple flow algorithm is planned in the next version. Spatially distributed models enable to estimate not only surface runoff but also flow in the rills. Surface runoff is described in the model by kinematic wave equation. Equation uses Manning roughness coefficient for surface runoff. Parameters for five different soil textures were calibrated on the set of forty measurements performed on the laboratory rainfall simulator. For modelling of the rills a specific sub model was created. This sub model uses Manning formula for flow estimation. Numerical stability of the model is solved by Courant criterion. Spatial scale is fixed. Time step is dynamically changed depending on how flow is generated and developed. SMODERP is meant to be used not only for the research purposes, but mainly for the engineering practice. 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

  18. 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.

  19. Modelling Soil Erosion Risk and its Impacts in the Mediterranean area for the 21st century

    NASA Astrophysics Data System (ADS)

    Le Bissonnais, Yves

    2010-05-01

    Soil degradation and erosion will be influenced during the 21st century both by climate and related or anthropogenic land use changes. Many current negative impacts of soil erosion may thus be amplified, and as certain soil thresholds are exceeded, potentially new and different problems could arise. Soils in the Mediterranean environment may be particularly vulnerable to such global changes because of contrasted climate, low vegetation cover and specific poor soil characteristics. It is therefore crucial to understand the potential impacts of global change on soils erosion and its consequences on soil functions such as support of vegetation, local water balance, loss of organic matter (on-site impacts) as well as on sediment transfer in surface water reservoirs (off-site impact). The objective of the work presented here was to improve our understanding of the impact of global change, as it can be predicted by currently used global change scenarios for the period until 2100, on soil resources and to develop indicators and models for soil vulnerability assessment within the Mediterranean basin. Specific drivers of soil erosion affected by the global change were identified and their impacts on erosion processes were quantified using erosion models at small and medium catchments scales. Soil vulnerability indicators were developed from the use of these models for the assessment of soil depth reduction and the siltation of reservoirs. The project also developed uncertainty analysis and validation of erosion prediction using results of field investigations in three test areas in France, Tunisia and Morocco.

  20. 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.

  1. Evaluating soil erodibility dynamics to improve estimates of wind erosion in drylands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion is a key driver of land degradation in the world’s drylands. Soil loss and nutrient decline due to wind erosion increase the sensitivity of drylands to climate stressors. Better understanding the factors controlling wind erosion in drylands will provide a basis for identifying and testi...

  2. Soil erosion on road and railways embankments in the Canyoles river Basin. Eastern Spain.

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Antonio, Giménez-Morera; Félix Ángel, González-Peñaloza; María, Burguet; Paulo, Pereira; José Reyes, Ruiz

    2013-04-01

    1 to 7 %. Time to ponding was 135.8 seconds, ranging from 131.1 and 158.7 seconds within four road embankments. Time to runoff was also very quick, with 367 seconds, ranging from 326.9 to 376.9 seconds after the start of the rain. The runoff outlet was reached after 402.08 seconds, ranging from 367.1 to 428.5 seconds. Runoff was 56.25 % of the rainfall, ranging from 54.93 % in the Road1 embankments to 57.08 % on the Railway1 embamkments. Sediment concentration was 41.41 g l-1 in average for the 40 rainfall simulation experiments and ranged from 40.20 to 42.54 g l-1. After 78 mm h-1 (156 liters on the 2m2 plots) of simulated rainfall during one hour, the total runoff collected was 87.75 %, with a very low variability within the four studied embankments an the 40 research plots (9 % variation coefficient). The sediment yield collected during the 25-year return period experiments resulted in 3.67 Kg in average values with again a low spatial variability (18 % variation coefficient). The soil erosion registered in the four-studied road and railway embankments reached a value of 18.25 Mg ha-1 h-1. The results shown above demonstrate that the water and soil losses in the road embankments under intense thunderstorms are very high, which is a general trend in Mediterranean ecosystems due to the climatologically conditions and the lack of restoration and rehabilitation strategies (Cerdà, 2007). The comparison with other research under different land uses show that the soil losses are very high on the road embankments due to the impact of the slope and the bare soil (Bakr et al., 2012) and show higher erosion rates than the unpaved forest roads (Jordán and Martínez Zavala, 2008). Scrublands, meadows, forest, and agriculture land in general show much lower soil losses at the study area (García Orenes et al., 2009). This is why most of the current research is developing strategies to control the soil and water losses (Persyn et al., 2004: Xu et al., 2006; de Oñae et al

  3. The magnetic susceptibility of European agricultural soils

    NASA Astrophysics Data System (ADS)

    Fabian, K.; Reimann, C.

    2012-04-01

    The GEMAS (Geochemical mapping of agricultural soils) project, a cooperation project between EuroGeoSurveys and Eurometaux, aims at providing soil quality data for Europe. Samples of arable soil were taken during 2008 at an average density of 1 site/2500 km2 covering the member states of the European Union (except Malta and Romania) and several neighbouring countries (e.g., Norway, Serbia, Ukraine). While the primary aim of the GEMAS project is to produce REACH (Registration, Evaluation and Authorisation of CHemicals - EC, 2006) consistent soil geochemistry data at the continental scale, the data set is also optimally apt to provide the first continental scale overview of magnetic properties in European soils. Soil samples from the upper 20 cm were taken as composites from 5 sites spread over a ca. 100 m2 area in a large agricultural field (Ap-sample). The samples were air dried and sieved to pass a 2 mm nylon screen. Weight normalized magnetic susceptibility of these dried samples was measured using a Sapphire Instruments SI2B susceptibility meter with dynamic background removal. The here presented maps of magnetic susceptibility in relation to geochemical composition and geological structures for the first time allow to outline the large scale influence of tectonics and climate on magnetic mineral concentration in European soils. The data set also provides the background variability for regional studies aiming to relate magnetic susceptibility of soils to local contamination sources.

  4. Effects of land use systems on soil erosion in a sloping Mediterranean watershed in Cyprus: From qualitative assessments to quantitative models

    NASA Astrophysics Data System (ADS)

    Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado; Zoumides, Christos

    2015-04-01

    In arid and semi-arid regions, water catchment sediment yield as a result of water erosion is difficult to model. Applicability of quantitative, process-based soil erosion models at a catchment scale is often problematic due to large data requirements and difficulty of describing all erosion and sediment transport processes. On the other hand, qualitative models require less data and include almost all evident erosion processes, which make them especially suited for watershed erosion assessments. The objective of this study is to compare water erosion estimates of the quantitative PESERA model with qualitative assessments obtained by WOCAT mapping methodology. The PESERA model simulates soil loss based on land cover, soil, climate and vegetation data, while the WOCAT methodology is based on expert observations per land use systems. This study is conducted in the Peristerona Watershed in Cyprus. The study area is 106.4 km2 and has a mean local slope higher than 40% for the mountainous upstream area and less than 8% for plain. Sixteen different land cover types with varying intensity of agriculture were distinguished during the WOCAT field assessment. WOCAT methodology ranked the land cover "complex cultivation" as the most degraded (degree: evident signs of water erosion, extent: 50% of the area, rate: moderately increasing in time),"agriculture, significant area natural vegetation" as less degraded (degree: evident signs of water erosion, extent: 30% of the area, rate: decreasing slowly in time) and "forests" the least degraded (some signs of water erosion, extent 5% of the area, rate: decreasing slowly in time). The classified WOCAT units will be compared with the erosion estimates obtained by the PESERA model. This study provides a linkage between qualitative soil erosion methods with quantitative models and helps to translate the outcomes of the former into latter.

  5. Evaluating uncertainty in 7Be-based soil erosion estimates: an experimental plot approach

    NASA Astrophysics Data System (ADS)

    Blake, Will; Taylor, Alex; Abdelli, Wahid; Gaspar, Leticia; Barri, Bashar Al; Ryken, Nick; Mabit, Lionel

    2014-05-01

    Soil erosion remains a major concern for the international community and there is a growing need to improve the sustainability of agriculture to support future food security. High resolution soil erosion data are a fundamental requirement for underpinning soil conservation and management strategies but representative data on soil erosion rates are difficult to achieve by conventional means without interfering with farming practice and hence compromising the representativeness of results. Fallout radionuclide (FRN) tracer technology offers a solution since FRN tracers are delivered to the soil surface by natural processes and, where irreversible binding can be demonstrated, redistributed in association with soil particles. While much work has demonstrated the potential of short-lived 7Be (half-life 53 days), particularly in quantification of short-term inter-rill erosion, less attention has focussed on sources of uncertainty in derived erosion measurements and sampling strategies to minimise these. This poster outlines and discusses potential sources of uncertainty in 7Be-based soil erosion estimates and the experimental design considerations taken to quantify these in the context of a plot-scale validation experiment. Traditionally, gamma counting statistics have been the main element of uncertainty propagated and reported but recent work has shown that other factors may be more important such as: (i) spatial variability in the relaxation mass depth that describes the shape of the 7Be depth distribution for an uneroded point; (ii) spatial variability in fallout (linked to rainfall patterns and shadowing) over both reference site and plot; (iii) particle size sorting effects; (iv) preferential mobility of fallout over active runoff contributing areas. To explore these aspects in more detail, a plot of 4 x 35 m was ploughed and tilled to create a bare, sloped soil surface at the beginning of winter 2013/2014 in southwest UK. The lower edge of the plot was bounded by

  6. Development of a virtual tool for the quantification and the analysis of soil erosion in olive orchards based on RUSLE

    NASA Astrophysics Data System (ADS)

    Marín, Víctor; Taguas, Encarnación V.; Redel, María Dolores; Gómez, Jose A.

    2013-04-01

    Erosion rates above 30 t ha-1 yr-1 have been measured in hilly agricultural regions such as Andalusia in Southern Spain, associated to orchard crops (Gómez et al., 2008). In this region, there are 1.48 Mha of olive groves (CAP, 2007), which are essential in terms of income, employment and landscape. The acquisition of training and experience in modelling soil erosion is difficult by the conventional system teaching for students as well as specific technicians. This paper presents a telematic training/analysis tool, CREO (Calculator of Rates of Erosion in Olive crops/ Calculadora RUSLE para Erosión en Olivar), to quantify erosion rates in olive grove areas based on the Revised Universal Soil Loss Equation (RUSLE; Renard et al., 1997) and on specific information published on soil losses and soil characteristics in olive orchards in Southern Spain. The tool has been programmed with Matlab R2008a from MathWorks Inc. (USA), although it could be used as an executable program in Spanish and English language by interested users. It consists of seven menus with visual material where different sources, databases and methodologies are presented to quantify soil rates (A = R.K.LS.C.P) by the calculation of six factors.A is computed in t ha-1 yr-1; R is the rainfall erosivity factor (MJ mm ha-1.h-1 yr-1); K represents the soil erodibility (t ha h ha-1 MJ-1 mm-1); L is the slope length factor and S is the slope gradient factor (dimensionless); C is a cover management factor (dimensionless) and P is a support practice factor (dimensionless). Different equations and methodologies can be selected by the user for the calculation of each factor while recommendations and advice can be showed for the suitable use of the tool. It is expected that CREO was a valuable helpful tool in environmental studies associated to olive orchard land use and its further use allows a better understanding of the interaction among the different factors involved, and better access to available

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. Erosion control in orchards and vineyards by a new soil and cover crop management method

    NASA Astrophysics Data System (ADS)

    Hartl, Wilfried; Guettler, Hans; Auer, Karl; Erhart, Eva

    2016-04-01

    Cover crops are the basis for an erosion-free soil management in orchards and vineyards. The soil cover provided by the foliage and the intensive root formation counteract erosion. Cover crops provide the soil microfauna with fresh organic matter which improves soil structure and porosity. The water demand of cover crops, however, may pose problems for the water supply of the trees and vines in dry seasons. Therefore it is necessary to adjust the growth of the cover crops to the actual water conditions. In years with ample precipitation cover crops may be allowed lush vegetative growth till flowering and formation of seeds. In dry years, the growth of the cover crop must be restricted to stop the competition for water, sometimes even by cutting off the cover crop roots. The course of the weather is incalculable and rainfall may be very variable during the year, so it is sometimes necessary to adust the cover crop management several times a year. A new special equipment, which can perform all the tasks necessary for the flexible cover crop management has been developed together with the agricultural machinery manufacturers Bodenwerkstatt Ertl-Auer GmbH and Güttler GmbH. The GreenManager® device consists of three modules, namely a specific type of cultivator, a harrow and a prismatic roller with seeding equipment, which can be used separately or in combination. The GreenManager® can reduce cover crops by flattening the plants in the whole row middle, by bringing down the cover crops with the harrow, or by horizontally cutting the cover crop roots a few centimetres beneath the soil surface in the central part of the row middle or in the whole row middle. These measures reduce the water competition by cover crops without generating further losses of soil moisture through intensive soil cultivation. At the same time the risk of soil erosion is kept to a minimum, because the soil remains covered by dead plant biomass. In one passage the GreenManager® can direct

  16. The economic cost of upland and gully erosion on subsistence agriculture for a watershed in the Ethiopian highlands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper quantifies the cost of erosion; it uses nutrient replacement cost to value topsoil nutrient depletion, daily wage rate to monetize the opportunity cost of labour due to gully erosion and local market price to quantify the lost animal and cash crop trees. Soil erosion rate is estimated fro...

  17. 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

  18. 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

  19. [Effects and mechanisms of plant roots on slope reinforcement and soil erosion resistance: a research review].

    PubMed

    Xiong, Yan-Mei; Xia, Han-Ping; Li, Zhi-An; Cai, Xi-An

    2007-04-01

    Plant roots play an important role in resisting the shallow landslip and topsoil erosion of slopes by raising soil shear strength. Among the models in interpreting the mechanisms of slope reinforcement by plant roots, Wu-Waldron model is a widely accepted one. In this model, the reinforced soil strength by plant roots is positively proportional to average root tensile strength and root area ratio, the two most important factors in evaluating slope reinforcement effect of plant roots. It was found that soil erosion resistance increased with the number of plant roots, though no consistent quantitative functional relationship was observed between them. The increase of soil erosion resistance by plant roots was mainly through the actions of fiber roots less than 1 mm in diameter, while fiber roots enhanced the soil stability to resist water dispersion via increasing the number and diameter of soil water-stable aggregates. Fine roots could also improve soil permeability effectively to decrease runoff and weaken soil erosion.

  20. 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.

  1. Relationships between soil erosion risk, soil use and soil properties in Mediterranean areas. A comparative study of three typical sceneries

    NASA Astrophysics Data System (ADS)

    Gil, Juan; Priego-Navas, Mercedes; Zavala, Lorena M.; Jordán, Antonio

    2013-04-01

    Generally, literature shows that the high variability of rainfall-induced soil erosion is related to climatic differences, relief, soil properties and land use. Very different runoff rates and soil loss values have been reported in Mediterranean cropped soils depending on soil management practices, but also in soils under natural vegetation types. OBJECTIVES The aim of this research is to study the relationships between soil erosion risk, soil use and soil properties in three typical Mediterranean areas from southern Spain: olive groves under conventional tillage, minimum tillage and no-till practices, and soils under natural vegetation. METHODS Rainfall simulation experiments have been carried out in order to assess the relationship between soil erosion risk, land use, soil management and soil properties in olive-cropped soils under different types of management and soils under natural vegetation type from Mediterranean areas in southern Spain RESULTS Results show that mean runoff rates decrease from 35% in olive grove soils under conventional tillage to 25% in olive (Olea europaea) grove soils with minimum tillage or no-till practices, and slightly over 22% in soils under natural vegetation. Moreover, considering the different vegetation types, runoff rates vary in a wide range, although runoff rates from soils under holm oak (Quercus rotundifolia), 25.70%, and marginal olive groves , 25.31%, are not significantly different. Results from soils under natural vegetation show that the properties and nature of the organic residues play a role in runoff characteristics, as runoff rates above 50% were observed in less than 10% of the rainfall simulations performed on soils with a organic layer. In contrast, more than half of runoff rates from bare soils reached or surpassed 50%. Quantitatively, average values for runoff water losses increase up to 2.5 times in unprotected soils. This is a key issue in the study area, where mean annual rainfall is above 600 mm

  2. 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...

  3. Soil biology and carbon in dryland agriculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of this paper is to explore potential management strategies in dryland agriculture that can promote soil health and crop productivity. Traditional crop production in the semiarid Great Plains consists of conventional tillage management of winter wheat (Triticum aestivum L.) - summer fallow....

  4. Transport of agricultural contaminants through karst soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Karst landscapes are common in many agricultural regions in the US. Well-developed karst landscapes are characterized by shallow soils, sinkholes, sinking streams, underground conduits, and springs. In these landscapes surface runoff is minimal and most recharge enters the subsurface relatively quic...

  5. Soil archives of mardel deposits: the impact of Late Holocene vegetation development, climatic oscillations and historical land use on soil erosion in Luxembourg

    NASA Astrophysics Data System (ADS)

    van Mourik, Jan; Slotboom, Ruud

    2014-05-01

    Mardel genesis. Mardels are small scale circular to elongated closed depressions (Ø > 50 m). They occur in Luxembourg on the Lias plateau in the Gutland, but also in other regions with landscapes, developed on Keuper and Lias deposits (as Lorraine). We can distinguish geogenetic and anthropogenic mardels. There are two types of genetic mardels, sink holes (controlled by diaclases in the Luxembourger sandstone and 'true mardels' or subsidence basins (controlled by dissolved gypsic lenses in marls of the Keuper deposits). These mardels developed during the Holocene. The age of the mardel sediments is Subatlantic; the sediments have been deposited on a palaeosol. Anthropogenic mardels are the result of historic clay excavation (Roman Time or younger). The age of these mardels is Subatlantic. The age of the sediments is also Subatlantic; the sediments have been deposited on a truncated soil in excavations. In all the genetic types of mardels, the sediments can consist of peat, peaty loam, or colluvic clayloam and the mardel sediments contain always valuable soil archives for the reconstruction of the impact of vegetation development, climatic oscillations and land use on soil erosion and deposition. Comparison of mardel deposits and valley deposits. - Pre-Holocene mardels have been eroded during the Weichselian. Geogenic mardels have been developed during the Holocene, anthropogenic mardels have been excavated since Roman Time. The age of the clastic (colluvic) deposits in mardels is Subatlantic - In the Late Glacial, valley bottoms were rather broad and covered with a gravelly bed load. Till the Subboreal river incision was active in primary valleys and peat accumulation took place on broad valley bottoms of secondary valleys. Since Celtic/Roman Time deforestation and extension of agriculture. During the Subatlantic colluvic/alluvic sedimentation took place on all the valley bottoms. The Subatlantic is a period of accelerated sedimentation of clastic sediments in

  6. Anthropogenic soil erosion over the Holocene: Application of a new dynamic soils module for global vegetation models

    NASA Astrophysics Data System (ADS)

    Kaplan, J. O.; Vanwalleghem, T.

    2012-04-01

    Over the course of the Holocene, anthropogenic activities have transformed the surface of the Earth. In no way has human impact been more important or longer lasting than the transformation of soils, where erosion and sediment transport over the past 10,000 years have led to irreversible changes in landscapes. Soil erosion also affected global carbon and nutrient cycles, and could have amplified or attenuated ongoing changes in the Earth's climate. To quantify the role of anthropogenically induced soil development and erosion in the Earth system, we developed a new module of global soil dynamics: soil formation, erosion, and sediment transport, that is suitable for global application at 0.5° resolution. We incorporated this soil module into the LPJ-DGVM and performed a series of simulations to quantify the spatial and temporal pattern of global soil change over the Holocene. The soil formation module models bedrock-to-soil conversion rates as exponentially decreasing with soil depth. Parameters for soil formation in different geological units were extracted from a review of existing literature. Our global soil erosion formulation is based on the Revised Universal Soil Loss Equation (RUSLE), but importantly accounts for sediment deposition and the net export of sediment out of a relatively large and geomorphologically heterogeneous gridcell. Our new module was developed by running the detailed soil erosion-deposition model WaTEM/SEDEM at 3 arc-second resolution to derive generalized topographical scaling relations that accurately represent hillslope length, slope gradient and sediment delivery ratio. We show that, at large spatial scale, sediment delivery ratio and the area affected by sediment deposition can be easily estimated from topographical parameters such as mean LS factor and wetness index. We include the feedback between soil formation and soil erosion by adjusting the soil erosion rates for soil depth and stoniness. The results of our Holocene

  7. 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

  8. Interactive assessment of the splash erosion and aggregate breakdown mechanism for the soils of different semi-arid land uses

    NASA Astrophysics Data System (ADS)

    Deviren Saygin, S.; Erpul, G.

    2012-04-01

    Aggregate breakdown mechanism is the most important process in splash erosion, producing the detached particles which are more easily transportable. In this study we aimed to determine the relationships between splash erosion and aggregate stability in laboratory conditions using the soils of three different land uses (agricultural land, grassland and forest). The rainfall simulations were conducted with the slope degrees (%9, 15 and 20) under two rainfall intensities (80 and 120 mm h-1). The soil samples were taken from a semi arid catchment, located in Ankara, Turkey. Before located into the test pans for rainfall simulations, the soils were sieved between 8 and 0.25 mm sieve size to obtain macro aggregate sizes and then wetted to bring them at saturation. To collect the splashed soil aggregates, the splash panels were located along two sides of a pan. Splashed particles by raindrop impacts were sampled every 5 min during 60 min rainfall simulations. Soil aggregate breakdown was evaluated by the mean weight diameter values (MWD, mm) of the collected splash sediments. The results indicated that aggregate size distributions were mostly changed with the land uses types. The MWD values were between 0.32 and 0.68 mm; 0.35 and 0.56 mm; and 0.53 and 1.20 mm for the soils of the agricultural land, grassland and forest, respectively. The forest soils having higher soil organic carbon content than those of agricultural land and grassland had more stable soil structure under destructive rainfall conditions (*P < 0.05) than grassland and agricultural area. The differences in the soil organic carbon content played a very crucial role in protecting the soils of the semi arid ecosystem against the aggregate breakdown by the splash erosion process. Additionally, the highest sediment amount was obtained with the rainfall simulations over the agricultural soils. Increases in the rainfall intensity or in the rainfall energy flux also resulted in MWD variations for the splash

  9. Identification of soil erosion risk areas for conservation planning in different states of India.

    PubMed

    Sharda, V N; Mandal, Debashis; Ojasvi, P R

    2013-03-01

    Assessment of soil erosion risks, especially in the developing countries, is a challenging task mainly due to non-availability or insufficiency of relevant data. In this paper, the soil erosion risks have been estimated by integrating the spatial data on potential erosion rates and soil loss tolerance limits for conservation planning at state level in India. The erosion risk classes have been prioritized based upon the difference between the prevailing erosion rates and the permissible erosion limits. The analysis revealed that about 50% of total geographical area (TGA) of India, falling in five priority erosion risk classes, requires different intensity of conservation measures though about 91% area suffers from potential erosion rates varying from < 5 to > 40 t ha(-1) yr(-1). Statewise analysis indicated that Andhra Pradesh, Maharashtra and Rajasthan share about 75% of total area under priority Class 1 (6.4 M ha) though they account for only 19.4% of the total area (36.2 M ha) under very severe potential erosion rate category (> 40 t ha(-1)yr(-1)). It was observed that about 75% of total geographical area (TGA) in the states of Bihar, Gujarat, Haryana, Kerala and Punjab does not require any specific soil conservation measure as the potential erosion rates are well within the tolerance limits. The developed methodology can be successfully employed for prioritization of erosion risk areas at watershed, region or country level.

  10. Soil erosion and associated organic carbon transfer along the southern Amazon land use frontier - status quo and future scenarios

    NASA Astrophysics Data System (ADS)

    Schindewolf, Marcus; Herrmann, Anne-Kathrin; Herrmann, Marie-Kristin; Amorim, Ricardo S. S.; Schmidt, Jürgen

    2016-04-01

    The Southern Amazon deforestation arc is one of the world's most dynamically changing landscapes mainly caused by global demands on animal products. Already more than 50 % of the savanna vegetation in Mato Grosso is converted to agricultural land. Following the BR-163 highway to the north deforestation is continuing, where former tropical rainforest is converted to pastures. Consequences are expected to be negative and highly relevant concerning soil functions. Soil losses and related carbon transfer by water erosion are likely to occur on a larger scale. Within the Carbiocial project, the impact of land use changes on soil loss was measured by applying artificial rainfall simulations. Experimental results were used to parameterize the physical based EROSION 3D simulation model in two meso-scale watersheds. The impact of future land use and climate scenarios on soil erosion and particle bound organic carbon transfer were simulated in addition to present day effects. Our results allow different predictions: Land use changes from natural vegetation to pasture lead to increased surface runoffs and soil losses. Due to the predominant no-tillage management, croplands do not reveal a similar behaviour; runoff and sediment yields are close to the initial level. Particle bound organic carbon losses are negligible compared to the removal of biomass during deforestation. Compared to the land use change effect more significant differences appear concerning the predominant soil types of the study region. Deterioration of soil functions are less pronounced for Ferralsols with a stable microstructure than for Acrisols. Additionally, our data suggest, that the main soil losses are related to the narrow time windows of land use conversion. Consequently, intensifying production on existing agricultural land rather than creating new production area (deforestation) might be the most practical way of preserving soils of the Southern Amazon.

  11. Soil erosion and mitigation measures on rented and owned fields in Uruguay: the impact of transgenic soya and foreign investors

    NASA Astrophysics Data System (ADS)

    Caon, Lucrezia; Kessler, Aad; Keesstra, Saskia; Cruze, Rick

    2014-05-01

    Governments, companies and individuals with financial capital to invest, are worldwide buying or renting land in developing or third world countries. Uruguay is a developing country whose economy is mainly based on agriculture. Since 2000 many foreigners started to invest in the Uruguayan agricultural sector and to practice intensive large-scale agriculture. The significant presence of foreigners in the country is proven by the fact that almost 360 000 ha out of the 500 000 ha forming the study area were managed by foreigners in 2012. Nowadays farmers have abandoned the traditional crop rotation plan that included pasture to produce grain for export, and transgenic soya (soya RR) became the main crop planted by both foreigners and locals. Besides the high soil erosion rates related to having soya as main crop, planting soya implies the use of glyphosate, a broad-spectrum systemic herbicide leading to important environmental impacts. It is commonly said that foreigners investing in poor countries are exploiting the local natural resources aiming to get the highest possible profit from them. Is this a valid assumption in Uruguay? The purpose of this study was to compare the land management style of foreign and local farmers and to relate it to the soil erosion occurring in the study area. The land tenure (rented or owned fields) and the type of farmer interviewed ("individual farmer" equivalent to L.L.C. or "anonymous society" equivalent to P.L.C.) were taken into consideration during the analysis. Based on what stated by the farmers interviewed, the soil erosion simulations considered the seven most popular crop rotation plans on rented and owned fields, three ideals crop rotation plans, the application of no mitigation measures, and the construction of terraces and conservation buffers. Depending on the crop rotation plan, soils characterized by slope gradients higher than 2 resulted in soil erosion rates higher than the 7 ton/ha/year allowed by law. The highest

  12. 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...

  13. 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...

  14. 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 ...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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.

  20. Australian net (1950s-1990) soil organic carbon erosion: implications for CO2 emission and land-atmosphere modelling

    NASA Astrophysics Data System (ADS)

    Chappell, A.; Webb, N. P.; Viscarra Rossel, R. A.; Bui, E.

    2014-09-01

    The debate remains unresolved about soil erosion substantially offsetting fossil fuel emissions and acting as an important source or sink of CO2. There is little historical land use and management context to this debate, which is central to Australia's recent past of European settlement, agricultural expansion and agriculturally-induced soil erosion. We use "catchment" scale (∼25 km2) estimates of 137Cs-derived net (1950s-1990) soil redistribution of all processes (wind, water and tillage) to calculate the net soil organic carbon (SOC) redistribution across Australia. We approximate the selective removal of SOC at net eroding locations and SOC enrichment of transported sediment and net depositional locations. We map net (1950s-1990) SOC redistribution across Australia and estimate erosion by all processes to be ∼4 Tg SOC yr-1, which represents a loss of ∼2% of the total carbon stock (0-10 cm) of Australia. Assuming this net SOC loss is mineralised, the flux (∼15 Tg CO2-equivalents yr-1) represents an omitted 12% of CO2-equivalent emissions from all carbon pools in Australia. Although a small source of uncertainty in the Australian carbon budget, the mass flux interacts with energy and water fluxes, and its omission from land surface models likely creates more uncertainty than has been previously recognised.

  1. Australian net (1950s-1990) soil organic carbon erosion: implications for CO2 emission and land-atmosphere modelling

    NASA Astrophysics Data System (ADS)

    Chappell, A.; Webb, N. P.; Viscarra Rossel, R. A.; Bui, E.

    2014-05-01

    The debate about soil erosion substantially offsetting fossil fuel emissions and acting as an important source or sink of CO2 remains unresolved. There is little historical land use and management context to this debate which is central to Australia's recent past of European settlement, agricultural expansion and agriculturally-induced soil erosion. We use "catchment" scale (∼25 km2) estimates of 137Cs-derived net (1950s-1990) soil redistribution of all processes (wind, water and tillage) to calculate the net soil organic carbon (SOC) redistribution across Australia. We approximate the selective removal of SOC at net eroding locations and SOC enrichment of transported sediment and net depositional locations. We map net (1950s-1990) SOC redistribtion across Australia and estimate erosion by all processes ∼4 Tg SOC yr-1 which represents a~loss of ∼2% of the total carbon stock (0-10 cm) of Australia. Assuming this net SOC loss is mineralised, the flux (∼15 Tg CO2-e yr-1) represents an omitted 12% of CO2-e emissions from all carbon pools in Australia. Although a small source of uncertainty in the Australian carbon budget, the mass flux interacts with energy and water fluxes and its omission from land surface models likely creates more uncertainty than has been previously recognised.

  2. The impact of the soil surface properties in water erosion seen through LandSoil model sensitivity analysis

    NASA Astrophysics Data System (ADS)

    Ciampalini, Rossano; Follain, Stéphane; Cheviron, Bruno; Le Bissonnais, Yves; Couturier, Alain; Walter, Christian

    2014-05-01

    Quantitative models of soil redistribution at the landscape scale are the current tools for understanding space-time processes in soil and landscape evolution. But models use larger and larger numbers of variables and sometimes it becomes difficult to understand their relative importance and model behaviours in critical conditions. Sensitivity analysis (SA) is widely used to clarify models behaviours, their structure giving fundamental information to ameliorate models their selves. We tested the LandSoil model (LANDscape design for SOIL conservation under soil use and climate change) a model designed for the analysis of agricultural landscape evolution at a fine spatial resolution scale [1-10 meters] and a mid-term temporal scale [10-100 years]. LandSoil is suitable for simulations from parcel to catchment scale. It is spatially distributed, event-based, and considers water and tillage erosion processes that use a dynamic representation of the agricultural landscape through parameters such as a monthly representation of soil surface properties. Our aim was to identify most significant parameters driving the model and to highlight potential particular/singular behaviours of parameter combinations and relationships. The approach was to use local sensitivity analysis, also termed 'one-factor-at-time' (OAT) which consists of a deterministic, derivative method, inquiring the local response O to a particular input factor Pi at a specified point P0 within the full input parameter space of the model expressed as: δO/δP = (O2-O1) / (P2-P1) The local sensitivity represents the partial derivatives of O with respect to Pi at the point P0. In the SA procedure the topographical entity is represented by a virtual hillslope on which soil loss and sensitivity are calculated. Virtual hillslope is inspired from the virtual catchment framework proposed by Cheviron at al. (2011): a fixed topology consisting of a 3X3 square pixel structure having 150 m length allowing to test

  3. 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.

  4. Linking the field to the stream: soil erosion and sediment yield in a rural catchment, NW Spain

    NASA Astrophysics Data System (ADS)

    Rodriguez-Blanco, M. L.; Taboada-Castro, M. M.; Palleiro-Suarez, L.; Taboada-Castro, M. T.

    2009-04-01

    Quantifying the linkages between field erosion, fluvial response and catchment sediment yield remains problematic, among other reasons, because of the re-deposition of eroded sediment within the catchment, which is controlled by the spatial organization of the land use and the connectivity between sediment sources and the stream network. This paper presents the results of an integrated study that considered the relationship between erosion and stream sediment yield in an agroforestry catchment (16 km2) in NW Spain. The geology consists of basic metamorphic schist. The relieve of the area is steeper, the mean slope is approximately 19%. Main soil types are classified as Umbrisol and Cambisol. Soils are acidic and rich in organic matter. The soil texture is silt and silt-loam. Land cover consists of a mixture of forest (65%) and agricultural fields (mainly grassland, pasture and maize). The study combined measurements of soil erosion by concentrate flow and sediment deposition at field scale with sediment yield measured at the catchment outlet. The hydrological data and water samples were obtained at the catchment outlet. Stream water level was monitored continuously and converted to discharge using a rating curve. The sampling for suspended sediments was supplemented by an automatic sampler. Suspended sediment load was calculated from the suspended sediment concentrations and discharge data. Eroded volume was calculated from cross-sections (measured at specific points, where the section changed abruptly) and length of the channel segments. The total sediment delivered to stream was determined as the difference between all erosion features (rills and gullies) and the sediment volumes that were deposited on the fields. The results showed that in the catchment during the period winter 2007/08 soil erosion by concentrate flow, i.e. rills and ephemeral gullies, occurred on unprotected crop field. Erosion by concentrate flow was highly discontinuous within the catchment

  5. 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.

  6. Using Cesium-137 technique to study the characteristics of different aspect of soil erosion in the Wind-water Erosion Crisscross Region on Loess Plateau of China.

    PubMed

    Li, Mian; Li, Zhan-bin; Liu, Pu-ling; Yao, Wen-yi

    2005-01-01

    The most serious soil erosion on Loess Plateau exists in the Wind-water Erosion Crisscross Region. In the past 20 years, the types and intensity of soil erosion and its temporal and spatial distribution were studied, but studies on the difference of soil erosion between slope aspects and slope positions in this area have no report. However, it is very important to analyze and evaluate quantitatively the characteristics of different aspects and positions of soil loss for the prevention and treatment of soil erosion in this area. The spatial pattern of net soil loss on 4 downslope transects in four aspects (east, west, south and north) on a typical Mao (round loess mound) in Liudaogou catchment in Wind-water Erosion Crisscross Region was measured in 2000 using the resident cesium-137 deficit technique. The purposes of this investigation were undertaken to determine whether or not 137Cs measurement would give a useful indication of the extent of soil loss and their characteristics from cultivated hillsides in different slope aspect and slope position in the study area. The results showed that the difference of soil erosion in different aspect was significant and the erosion rate was in this order: north > east > south > west. Compared with other areas, the difference of erosion rate between north hillside and south hillside was on the contrary, and the possible explanations could be the effect of wind erosion. Also, the percentage of wind erosion was estimated to be at least larger than 18% of total soil loss by comparing the difference of erosion amount in south hillside and north hillside. The erosion rates on different slope positions in all aspects were also different, the highest net soil loss occurred in the lower slope position, and the upper and middle slope positions were slight. The general trend of net soil loss on sloping surface was to increase in fluctuation with increasing downslope distance.

  7. 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.

  8. Adapting the RUSLE and GIS to model soil erosion risk in a mountains karst watershed, Guizhou Province, China.

    PubMed

    Yue-Qing, Xu; Xiao-Mei, Shao; Xiang-Bin, Kong; Jian, Peng; Yun-Long, Cai

    2008-06-01

    Soil erosion is a serious environmental problem in Guizhou Province, which is located in the centre of the karst areas of southwestern China. Unfortunately, Guizhou Province suffers from a lack of financial resources to research, monitor and model soil erosion at large watershed. In order to assess the soil erosion risk, soil erosion modeling at the watershed scale are urgently needed to be undertaken. This study integrated the Revised Universal Soil Loss Equation (RUSLE) with a Geographic Information System (GIS) to estimate soil loss and identify the risk erosion areas in the Maotiao River watershed, which is a typical rural watershed in Guizhou Province. All factors used in the RUSLE were calculated for the watershed using local data. It was classified into five categories ranging from minimal risk to extreme erosion risk depending on the calculated soil erosion amount. The soil erosion map was linked to land use, elevation and slope maps to explore the relationship between soil erosion and environmental factors and identify the areas of soil erosion risk. The results can be used to advice the local government in prioritizing the areas of immediate erosion mitigation. The integrated approach allows for relatively easy, fast, and cost-effective estimation of spatially distributed soil erosion. It thus indicates that RUSLE-GIS model is a useful and efficient tool for evaluating and mapping soil erosion risk at a large watershed scale in Guizhou Province.

  9. Mapping soil erosion hazard in a recently burnt forest area in north-central Portugal

    NASA Astrophysics Data System (ADS)

    Vieira, D. C. S.; Malvar, M. C.; Nunes, J. P.; Keizer, J. J.

    2009-04-01

    The present work has as overall objective to evaluate the suitability of two easily-applied erosion models for slope-scale erosion risk mapping, using a Geographic Information System, following wildfire. It was carried out in the framework of the EROSFIRE project, which, in a nutshell, wants to assess the advantages and disadvantages of field rainfall simulation experiments for mapping erosion risk, in particular by providing the input data needed for model calibration. The Universal Soil Loss Equation (USLE) and the Morgan-Morgan-Finney model (MMF) were selected in this study mainly for ease of application. In spite both models were specifically developed for agricultural fields, there exist off-the-shelf model parameter values that apparently or supposedly are suitable for recently burnt forest areas. Furthermore, USLE was applied by the Portuguese National Water Institute following the dramatic wildfire season of the summer of 2003 and, as such, was a lead motif behind the EROSFIRE project. The two models were applied to a study area in north-central Portugal that burnt during the summer of 2005. The 270 hectares of burnt forest lands by and large consist of fast-growing eucalypt plantations but involve a notable variety of pre- as well as post-fire forestry management practices, the most conspicuous being the presence or construction of terraces. The model results were evaluated using three different sets of data: i) data from rainfall simulation experiments that were carried out at one or more occasions during the first year following the fire; ii) runoff and sediment loss data from unbounded slope-scale erosion plots at two sites, also during the first year following the fire; iii) data from a soil erosion features-survey carried out during 2008 at more than 20 slopes. As expected, the performance of both models revealed marked weaknesses, especially in relation to the survey results. At least in part this can be attributed to the lack of off

  10. 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

  11. Production, soil erosion and economic failure in new citrus plantations in Eastern Spain

    NASA Astrophysics Data System (ADS)

    Giménez Morera, Antonio; Carles membrado, Joan; Cerdà, Artemi; Ángel González Peñaloza, Félix

    2013-04-01

    their neighboring mountain slopes. The interest of orange groves is not only economic, but also environmental. Although the traditional farming developed a beautiful man made landscape of terraces and irrigation ditches, the development of new irrigation systems by means of drips contributed to new plantations that removed the ditches and the terraces. Those changes are triggering intense soil erosion rates such were shown by previous researchers in Valencia (Cerdà et al., 2009). This impact is also shown in other regions with a similar citrus production evolution, and China is a clear example (Wang et al., 2010; Liu et al., 2012). This research evaluates the production and the cost of production, the economic investment in the establishment of the new citrus plantations and the revenues of 5 farms in the Canyoles river watershed in Eastern Spain. The soil erosion rates measured by means of rainfall simulation experiments in each farm by means of thunderstorms of 10 years return period (55 mm h-1) and by five-year survey by means of topographical measurements. The results show that the soil losses in the new plantation are extremely high, that the investments in the new plantation reached 18352 € ha-1 and that the revenues do not cover the expenses of production. Soil erosion measured since 2007 to 2011 show values that range from 7.54 to 56.76 Mg ha-1 year-1 and show a mean value of 28.45 Mg ha-1 year-1. Rainfall simulation experiments shown that the soil losses were very high as other researched found in new citrus plantations. The comparison with other land uses and agriculture crop and managements shown that soil erosion is higher in then new chemically treated plantations (Cerdà, 2002), and even higher that on road embankments (Cerdà, 2007) and rainfed agriculture soil (García Orenes et al., 2009), although the water repellency found was very low in comparison to organic farming orange plantations (González et al., 2012). The current situation of a high

  12. Presentation of the LESELAM observatory (Fight against Soil Erosion and siltation of the lagoon in Mayotte Island)

    NASA Astrophysics Data System (ADS)

    Lopez, Jean-Marie; Lidon, Bruno; Bozza, Jean-Louis; Dejean, Cyril; Benard, Bhavani; Parizot, Manuel; Puvilland, Pascal; Desprats, Jean-Francois; Rinaudo, Jean-Daniel; Colas, Bastien; Said, Kadafi; Mosnier, Sarah; Rouille, Antoine; Cerdan, Olivier

    2016-04-01

    As a consequence of a dramatic increase of its population, the Mayotte Island is undergoing significant land use changes, mainly through an increase in agricultural areas as well as unplanned urban sprawl. Resulting soil erosion in natural degraded areas, in agricultural fields or from rural habitat threatens the sustainability of agriculture, as well as the balance of the lagoon ecosystem, one of the largest in the world, by siltation of the aquatic environment by sediments and adsorbed pollutants. In order to implement pertinent and sustainable remediation measure there is a need to quantify the sediment fluxes, identify the sources areas and raise awareness of population on land degradation. In this context, the LESELAM project aims to involve local stakeholders in a collective effort to define and implement a set of technical and organizational practices in the fight against soil erosion for sustainable balance between the development of agriculture and rural housing on the one hand, and the quality of the lagoon environment, on the other hand. The operational objectives relate to (1) create an erosion observatory to characterize water erosion; (2) implement, in partnership with stakeholders, a demonstrator of good practice to test and evaluate at different scales different techniques of conservation agriculture and of remedial; and (3) structure collective and awareness action through a multi stakeholders approach and a significant communication component. The actions presented in this study refer to a multiscale hydro-sedimentary instrumentation (observatory) of the Mtsamboro and Dzoumogné catchments and on the first transfer of competence to the various stakeholders.

  13. Determination of soil erosion risk in the Mustafakemalpasa River Basin, Turkey, using the revised universal soil loss equation, geographic information system, and remote sensing.

    PubMed

    Ozsoy, Gokhan; Aksoy, Ertugrul; Dirim, M Sabri; Tumsavas, Zeynal

    2012-10-01

    Sediment transport from steep slopes and agricultural lands into the Uluabat Lake (a RAMSAR site) by the Mustafakemalpasa (MKP) River is a serious problem within the river basin. Predictive erosion models are useful tools for evaluating soil erosion and establishing soil erosion management plans. The Revised Universal Soil Loss Equation (RUSLE) function is a commonly used erosion model for this purpose in Turkey and the rest of the world. This research integrates the RUSLE within a geographic information system environment to investigate the spatial distribution of annual soil loss potential in the MKP River Basin. The rainfall erosivity factor was developed from local annual precipitation data using a modified Fournier index: The topographic factor was developed from a digital elevation model; the K factor was determined from a combination of the soil map and the geological map; and the land cover factor was generated from Landsat-7 Enhanced Thematic Mapper (ETM) images. According to the model, the total soil loss potential of the MKP River Basin from erosion by water was 11,296,063 Mg year(-1) with an average soil loss of 11.2 Mg year(-1). The RUSLE produces only local erosion values and cannot be used to estimate the sediment yield for a watershed. To estimate the sediment yield, sediment-delivery ratio equations were used and compared with the sediment-monitoring reports of the Dolluk stream gauging station on the MKP River, which collected data for >41 years (1964-2005). This station observes the overall efficiency of the sediment yield coming from the Orhaneli and Emet Rivers. The measured sediment in the Emet and Orhaneli sub-basins is 1,082,010 Mg year(-1) and was estimated to be 1,640,947 Mg year(-1) for the same two sub-basins. The measured sediment yield of the gauge station is 127.6 Mg km(-2) year(-1) but was estimated to be 170.2 Mg km(-2) year(-1). The close match between the sediment amounts estimated using the RUSLE

  14. Determination of soil erosion risk in the Mustafakemalpasa River Basin, Turkey, using the revised universal soil loss equation, geographic information system, and remote sensing.

    PubMed

    Ozsoy, Gokhan; Aksoy, Ertugrul; Dirim, M Sabri; Tumsavas, Zeynal

    2012-10-01

    Sediment transport from steep slopes and agricultural lands into the Uluabat Lake (a RAMSAR site) by the Mustafakemalpasa (MKP) River is a serious problem within the river basin. Predictive erosion models are useful tools for evaluating soil erosion and establishing soil erosion management plans. The Revised Universal Soil Loss Equation (RUSLE) function is a commonly used erosion model for this purpose in Turkey and the rest of the world. This research integrates the RUSLE within a geographic information system environment to investigate the spatial distribution of annual soil loss potential in the MKP River Basin. The rainfall erosivity factor was developed from local annual precipitation data using a modified Fournier index: The topographic factor was developed from a digital elevation model; the K factor was determined from a combination of the soil map and the geological map; and the land cover factor was generated from Landsat-7 Enhanced Thematic Mapper (ETM) images. According to the model, the total soil loss potential of the MKP River Basin from erosion by water was 11,296,063 Mg year(-1) with an average soil loss of 11.2 Mg year(-1). The RUSLE produces only local erosion values and cannot be used to estimate the sediment yield for a watershed. To estimate the sediment yield, sediment-delivery ratio equations were used and compared with the sediment-monitoring reports of the Dolluk stream gauging station on the MKP River, which collected data for >41 years (1964-2005). This station observes the overall efficiency of the sediment yield coming from the Orhaneli and Emet Rivers. The measured sediment in the Emet and Orhaneli sub-basins is 1,082,010 Mg year(-1) and was estimated to be 1,640,947 Mg year(-1) for the same two sub-basins. The measured sediment yield of the gauge station is 127.6 Mg km(-2) year(-1) but was estimated to be 170.2 Mg km(-2) year(-1). The close match between the sediment amounts estimated using the RUSLE

  15. Wind tunnel experimental study on the effect of PAM on soil wind erosion control.

    PubMed

    He, Ji-Jun; Cai, Qiang-Guo; Tang, Ze-Jun

    2008-10-01

    In recent years, high-molecular-weight anionic polyacrylamide (PAM) have been widely tested on a variety of soils, primarily in water erosion control. However, little information is available regarding the effectiveness of PAM on preventing soil loss from wind erosion. The research adopted room wind tunnel experiment, two kinds of soils were used which were from the agro-pastoral area of Inner Mongolia, the northwest of China, the clay content of soils were 22.0 and 13.7%, respectively. For these tests, all the treatments were performed under the condition of wind velocity of 14 m s(-1) and a blown angle of 8.75%, according to the actual situation of experimented area. The study results indicated that using PAM on the soil surface could enhance the capability of avoiding the wind erosion, at the same time, the effect of controlling wind soil erosion with 4 g m(-2) PAM was better than 2 g m(-2) PAM's. Economically, the 2 g m(-2) PAM used in soil surface can control wind erosion effectively in this region. The prophase PAM accumulated in soil could not improve the capability of avoiding the wind erosion, owing to the degradation of PAM in the soil and the continual tillage year after year. The texture of soil is a main factor influencing the capability of soil avoiding wind erosion. Soil with higher clay content has the higher capability of preventing soil from wind erosion than one with the opposite one under the together action of PAM and water.

  16. Use of modeled and satelite soil moisture to estimate soil erosion in central and southern Italy.

    NASA Astrophysics Data System (ADS)

    Termite, Loris Francesco; Massari, Christian; Todisco, Francesca; Brocca, Luca; Ferro, Vito; Bagarello, Vincenzo; Pampalone, Vincenzo; Wagner, Wolfgang

    2016-04-01

    This study presents an accurate comparison between two different approaches aimed to enhance accuracy of the Universal Soil Loss Equation (USLE) in estimating the soil loss at the single event time scale. Indeed it is well known that including the observed event runoff in the USLE improves its soil loss estimation ability at the event scale. In particular, the USLE-M and USLE-MM models use the observed runoff coefficient to correct the rainfall erosivity factor. In the first case, the soil loss is linearly dependent on rainfall erosivity, in the second case soil loss and erosivity are related by a power law. However, the measurement of the event runoff is not straightforward or, in some cases, possible. For this reason, the first approach used in this study is the use of Soil Moisture For Erosion (SM4E), a recent USLE-derived model in which the event runoff is replaced by the antecedent soil moisture. Three kinds of soil moisture datasets have been separately used: the ERA-Interim/Land reanalysis data of the European Centre for Medium-range Weather Forecasts (ECMWF); satellite retrievals from the European Space Agency - Climate Change Initiative (ESA-CCI); modeled data using a Soil Water Balance Model (SWBM). The second approach is the use of an estimated runoff rather than the observed. Specifically, the Simplified Continuous Rainfall-Runoff Model (SCRRM) is used to derive the runoff estimates. SCRMM requires soil moisture data as input and at this aim the same three soil moisture datasets used for the SM4E have been separately used. All the examined models have been calibrated and tested at the plot scale, using data from the experimental stations for the monitoring of the erosive processes "Masse" (Central Italy) and "Sparacia" (Southern Italy). Climatic data and runoff and soil loss measures at the event time scale are available for the period 2008-2013 at Masse and for the period 2002-2013 at Sparacia. The results show that both the approaches can provide

  17. [Sensitivity evaluation and key sensitive factors identification of soil erosion around Hangzhou Bay based on RUSLE].

    PubMed

    Li, Cheng; Li, Jun-Xiang; Zhu, Fei-Ge; Cao, Lu; Chen, Zhu; Wu, Tong; Wu, Ming; Sun, Hai-Jing

    2009-07-01

    By using GIS and RS techniques and RUSLE, the rainfall erosivity (R), soil erodibility (K), vegetation and management factor (C), and slope length and steepness factor (LS) around Hangzhou Bay of Zhejiang Province, China were calculated to make a comprehensive sensitivity evaluation of soil erosion in the study area. In the meantime, the contribution of each natural factor, i. e., rainfall, soil texture, slope, and elevation, was analyzed, and a new approach, overlapping and ordering method, was developed to identify the key affecting factors in the given sensitive areas. In the study area, soil erosion was mainly at non-sensitive and low sensitive levels. The percentages of the areas with different soil erosion sensitivity varied with the strength of the affecting factors. Soil erosion sensitivity increased with increasing rainfall and slope, and the percentage of the area with high soil erosion sensitivity was the largest at elevation 200-500 meters. The overlapping and ordering method was a practicable approach in identifying the key affecting factors in given sensitive areas, being helpful to understand the mechanisms causing soil erosion.

  18. 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

  19. 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.

  20. Soil erosion, climate change and global food security: challenges and strategies.

    PubMed

    Rhodes, Christopher J

    2014-01-01

    An overview is presented of the determined degree of global land degradation (principally occurring through soil erosion), with some consideration of its possible impact on global food security. Most determinations of the extent of land degradation (e.g. GLASOD) have been made on the basis of "expert judgement" and perceptions, as opposed to direct measurements of this multifactorial phenomenon. More recently, remote sensing measurements have been made which indicate that while some regions of the Earth are "browning" others are "greening". The latter effect is thought to be due to fertilisation of the growth of biomass by increasing levels of atmospheric CO2, and indeed the total amount of global biomass was observed to increase by 3.8% during the years 1981-2003. Nonetheless, 24% of the Earth's surface had occasioned some degree of degradation in the same time period. It appears that while long-term trends in NDVI (normalised difference vegetation index) derivatives are only broad indicators of land degradation, taken as a proxy, the NDVI/NPP (net primary productivity) trend is able to yield a benchmark that is globally consistent and to illuminate regions in which biologically significant changes are occurring. Thus, attention may be directed to where investigation and action at the ground level is required, i.e. to potential "hot spots" of land degradation and/or erosion. The severity of land degradation through soil erosion, and an according catastrophic threat to the survival of humanity may in part have been overstated, although the rising human population will impose inexorable demands for what the soil can provide. However the present system of industrialised agriculture would not be possible without plentiful provisions of cheap crude oil and natural gas to supply fuels, pesticides, herbicides and fertilisers. It is only on the basis of these inputs that it has been possible for the human population to rise above 7 billion. Hence, if the cheap oil and gas

  1. Soil erosion, climate change and global food security: challenges and strategies.

    PubMed

    Rhodes, Christopher J

    2014-01-01

    An overview is presented of the determined degree of global land degradation (principally occurring through soil erosion), with some consideration of its possible impact on global food security. Most determinations of the extent of land degradation (e.g. GLASOD) have been made on the basis of "expert judgement" and perceptions, as opposed to direct measurements of this multifactorial phenomenon. More recently, remote sensing measurements have been made which indicate that while some regions of the Earth are "browning" others are "greening". The latter effect is thought to be due to fertilisation of the growth of biomass by increasing levels of atmospheric CO2, and indeed the total amount of global biomass was observed to increase by 3.8% during the years 1981-2003. Nonetheless, 24% of the Earth's surface had occasioned some degree of degradation in the same time period. It appears that while long-term trends in NDVI (normalised difference vegetation index) derivatives are only broad indicators of land degradation, taken as a proxy, the NDVI/NPP (net primary productivity) trend is able to yield a benchmark that is globally consistent and to illuminate regions in which biologically significant changes are occurring. Thus, attention may be directed to where investigation and action at the ground level is required, i.e. to potential "hot spots" of land degradation and/or erosion. The severity of land degradation through soil erosion, and an according catastrophic threat to the survival of humanity may in part have been overstated, although the rising human population will impose inexorable demands for what the soil can provide. However the present system of industrialised agriculture would not be possible without plentiful provisions of cheap crude oil and natural gas to supply fuels, pesticides, herbicides and fertilisers. It is only on the basis of these inputs that it has been possible for the human population to rise above 7 billion. Hence, if the cheap oil and gas

  2. 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...

  3. Root Induced Heterogeneity In Agricultural Soils

    NASA Astrophysics Data System (ADS)

    Gomes, C.; Gabai, R.; Weisbrod, N.; Furman, A.

    2012-12-01

    In this study we investigate the role of plant induced heterogeneity on water dynamics in agricultural soils. We conducted three experiments in two sites (one still ongoing) in which a trench was excavated in the root zone of an orchard and the subsurface, to a depth of over 1 m, was instrumented in high resolution with water content, water potential and temperature sensors. High temporal resolution monitoring of soil state was carried for over a year, period that included natural (Mediterranean) climate boundary forcing. In addition, sprinkler, flood, and spray irrigation boundary conditions were forced for short time periods to explore the infiltration process under these conditions. One site was an Avocado orchard planted in red sandy soil while the other, still on-going, is in a grape vineyards irrigated by tap and treated wastewater, planted over alluvial clayey soil. In the vineyard, we are comparing soil irrigated with fresh water to soil irrigated with treated waste water for more than 10 years. Our preliminary results indicate several interesting phenomena. First, the role of plant roots is clearly seen as the major roots act as a conduit for water (and solute), providing a fast bypass of the upper soil. Further, we identified different regions of the subsurface that apparently were of the same texture, but in practice presented very different hydraulic properties. Second, the role of these roots depends on the boundary conditions. That is, the root bypass acts differently when soil is flooded than when flow is strictly unsaturated. As expected, simulation of the experimental results show good fit only if the domain heterogeneity of soil properties was incorporated. Results for the clayey soils were not available at time of abstract submission.

  4. Applicability of 239Pu as a tracer for soil erosion in the wet-dry tropics of northern Australia

    NASA Astrophysics Data System (ADS)

    Lal, R.; Tims, S. G.; Fifield, L. K.; Wasson, R. J.; Howe, D.

    2013-01-01

    The technique of accelerator mass spectroscopy (AMS) has been employed to determine modern soil loss rates through the analysis of 239Pu profiles in soil cores from the Daly basin in Northern Territory, Australia. In areas in which soil conservation banks were not present or were only added recently (<25a) and which had a history of grazing and cultivation the measured soil loss rates over the past ∼50 years were 7.5-19.5 t ha-1 a-1. The measured rates are up to 5 times higher compared to agricultural and uncultivated areas within soil conservation banks in other parts of the catchment. High intensity seasonal rainfall combined with reduction in land cover due to grazing and episodic bush fires are primary factors influencing erosion although other impacts on the landscape such as tillage generated runoff and land clearing seem to be responsible for accelerated sediment production.

  5. Combined use of fallout radionuclides and stable isotopes for investigating soil erosion processes in a Moroccan watershed

    NASA Astrophysics Data System (ADS)

    Benmansour, Moncef; Mabit, Lionel; Zouagui, Anis; Amenzou, Nouredinne; Sabir, Mohamed; Nouira, Asmae; Brandt, Christian; Rasche, Frank; Naimi, Mustapha; Chikhaoui, Mohamed; Marah, Hamid; Benkdad, Azzouz; Taous, Fouad

    2015-04-01

    On-site and off-site impacts associated with land degradation by soil erosion are a major concern in Morocco. This study aimed to use fallout radionuclides (FRNs): Caesium-137 (137Cs), excess Lead-210 (210Pbex) and Beryllium-7 (7Be) in combination with carbon and nitrogen stable isotopes (i.e. Carbon-13 (13C) and Nitrogen-15 (15N)) in estimating soil loss in the "My Bouchta" watershed and the origin of sediment deposits in a downstream water reservoir (i.e. "Talembout"). Using 137Cs, the net soil erosion rate, for the "My Bouchta" watershed over a period of 50 years, was estimated at 23 t/ha/yr with a main sediment contribution (> 90{%}) from the agricultural fields, the forest and shrub fields contributing to less than 10{%} of the overall sediment production. This result indicates clearly the role and the effectiveness of the forest plantations and vegetation cover to protect soil resource against erosion processes. The use of the 210Pb^ex technique in three different fields further highlighted that soil erosion rates over a period of 100 years were lower than those obtained by 137Cs reflecting the increase of soil loss during the last decades. Tests of fallout 7Be associated with short rainfall events in four fields confirmed the results obtained with 137Cs, that areas under natural vegetation were protected against erosion. Sedimentation rates were assessed for the "Talembout" water reservoir and the mean values obtained for two sediment cores using 210Pbex and the Constant Rate of Supply (CRS) model were about 0.51-0.58 g/cm^2/yr. The obtained results showed also a significant yearly increase of the sedimentation rate. The results derived from the stable isotopes depth profiles indicated similar behavior for forest and shrub fields. Furthermore, strong correlation between δ13C and total C was observed for this type of land use while for the agricultural fields, the correlation was not significant. In addition, the sediment profile of N-15 indicated an

  6. Quantitative and Qualitative Assessment of Soil Erosion Risk in Małopolska (Poland), Supported by an Object-Based Analysis of High-Resolution Satellite Images

    NASA Astrophysics Data System (ADS)

    Drzewiecki, Wojciech; Wężyk, Piotr; Pierzchalski, Marcin; Szafrańska, Beata

    2014-06-01

    In 2011 the Marshal Office of Małopolska Voivodeship decided to evaluate the vulnerability of soils to water erosion for the entire region. The quantitative and qualitative assessment of the erosion risk for the soils of the Małopolska region was done based on the USLE approach. The special work-flow of geoinformation technologies was used to fulfil this goal. A high-resolution soil map, together with rainfall data, a detailed digital elevation model and statistical information about areas sown with particular crops created the input information for erosion modelling in GIS environment. The satellite remote sensing technology and the object-based image analysis (OBIA) approach gave valuable support to this study. RapidEye satellite images were used to obtain the essential up-to-date data about land use and vegetation cover for the entire region (15,000 km2). The application of OBIA also led to defining the direction of field cultivation and the mapping of contour tillage areas. As a result, the spatially differentiated values of erosion control practice factor were used. Both, the potential and the actual soil erosion risk were assessed quantificatively and qualitatively. The results of the erosion assessment in the Małopolska Voivodeship reveal the fact that a majority of its agricultural lands is characterized by moderate or low erosion risk levels. However, high-resolution erosion risk maps show its substantial spatial diversity. According to our study, average or higher actual erosion intensity levels occur for 10.6 % of agricultural land, i.e. 3.6 % of the entire voivodeship area. In 20 % of the municipalities there is a very urgent demand for erosion control. In the next 23 % an urgent erosion control is needed. Our study showed that even a slight improvement of P-factor estimation may have an influence on modeling results. In our case, despite a marginal change of erosion assessment figures on a regional scale, the influence on the final prioritization of

  7. Quantitative and Qualitative Assessment of Soil Erosion Risk in Małopolska (Poland), Supported by an Object-Based Analysis of High-Resolution Satellite Images

    NASA Astrophysics Data System (ADS)

    Drzewiecki, Wojciech; Wężyk, Piotr; Pierzchalski, Marcin; Szafrańska, Beata

    2013-04-01

    In 2011 the Marshal Office of Małopolska Voivodeship decided to evaluate the vulnerability of soils to water erosion for the entire region. The quantitative and qualitative assessment of the erosion risk for the soils of the Małopolska region was done based on the USLE approach. The special work-flow of geoinformation technologies was used to fulfil this goal. A high-resolution soil map, together with rainfall data, a detailed digital elevation model and statistical information about areas sown with particular crops created the input information for erosion modelling in GIS environment. The satellite remote sensing technology and the object-based image analysis (OBIA) approach gave valuable support to this study. RapidEye satellite images were used to obtain the essential up-to-date data about land use and vegetation cover for the entire region (15,000 km2). The application of OBIA also led to defining the direction of field cultivation and the mapping of contour tillage areas. As a result, the spatially differentiated values of erosion control practice factor were used. Both, the potential and the actual soil erosion risk were assessed quantificatively and qualitatively. The results of the erosion assessment in the Małopolska Voivodeship reveal the fact that a majority of its agricultural lands is characterized by moderate or low erosion risk levels. However, high-resolution erosion risk maps show its substantial spatial diversity. According to our study, average or higher actual erosion intensity levels occur for 10.6 % of agricultural land, i.e. 3.6 % of the entire voivodeship area. In 20 % of the municipalities there is a very urgent demand for erosion control. In the next 23 % an urgent erosion control is needed. Our study showed that even a slight improvement of P-factor estimation may have an influence on modeling results. In our case, despite a marginal change of erosion assessment figures on a regional scale, the influence on the final prioritization of

  8. Soil erosion measurements by means of experimental plots to determine best land management strategies in vineyards and olive orchards

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Keesstra, Saskia; Jordan, Antonio; Brevik, Erik; Nova, Agata; Prosdocimi, Massimo; Azorín-Molina, César; Yazdanpanah, Najme; Mahmoodabadi, Majid; Pereira, Paulo; Burguet, María

    2016-04-01

    In order to design sustainable land management there is a need to have accurate information on the impact this land management strategies have on water and sediment dynamics. This is especially important when a proper management is designed to reduce the soil losses due to the complex interaction of mechanisms that interact within the soil erosion process. Soil erosion is an non-linear process, both spatially and temporally, and as a consequence of that only well-monitored and accurate measurements can give insights in the processes and how these processes can be influenced by management to reduce soil losses (Cerdà, 2007; Ligonja and Shrestha, 2015; Nanko et al., 2015; Seutloali and Beckedahl, 2015). This is necessary at different scales: pedon, slope, and watershed because the governing processes differ at different scale (Keesstra, 2007; Jordán and Martínez Zavala, 2008; Borrelli et al., 2015). Soil erosion plots can give information about the temporal and spatial variability of soil losses. We present here a strategy developed by the Soil Erosion and Degradation Research Group from the University of Valencia to assess the soil erosion rates in Eastern Spain. In 2002 the Soil Erosion Experimental Station in El Teularet-Sierra de Enguera was installed, to assess soil losses in rainfed agriculture orchards, and 73 plots of 1, 2, 4, 16 and 48 m2 were installed. In 2005 6 plots of 300 m2 were installed in the nearby Montesa soil erosion station to assess soil losses in citrus orchards. In 2011 16 plots of 2 m2 where installed in Les Alcusses to determine soil losses in olive orchards, and in 2015 8 plots in Celler del Roure vineyard to assess the impact of land management in vineyards and 8 plots in the El Teularet to study the impact of straw mulch on soil erosion rates. All erosion stations are located in several kilometres distance from each other. This research which we developed since 2002 is complementary to previous research where we used rainfall

  9. 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