Modified Universal Soil Loss Equation Research Articles

Development Land Erosion Model Using Model Builder GIS (Case Study: Citepus Watershed)

Land erosion is the impact of increasing runoff discharge and land use conversion to impervious areas. Land erosion usually calculated by formula called USLE (Universal Soil Loss Equation) then modified as MUSLE (Modified Universal Soil Loss Equation). These formula calculate average annual soil loss in tons/areas depends on rainfall erosivity (R), soil erodibility factor (K), topographic factor (LS), cropping and conservation factor (CP). GIS (Geographic Information System) is a system designed to capture, manipulate, and analyze spatial/geographic data. There are some tools related water resources analysis in ArcGIS such as: watershed analysis and also have a tools for user to create their own model called model builder. This research was aim to create a model to calculate land erosion using MUSLE formula by model builder in ArcGIS. The output for this research is the model which can be used to calculate annual soil loss in watershed area based on GIS systems. For the model trial and case study, we use Citepus watershed located on Bandung West Java, that has 5 river branches: Cibogo, Cikakak, Cilimus, Cipedes and Ciroyom. As the result of the model, the value of average annual soil loss in Citepus watershed can be calculated automatically by developed model.

Computation of hourly sediment discharges and annual sediment yields by means of two soil erosion models in a mountainous basin

ABSTRACTThe objective of this study is the estimate of sediment discharges and sediment yields deriving from soil and streambed erosion, at the basin scale. For this reason, continuous simulations of soil and streambed erosion processes are performed in the mountainous part of the Nestos River basin, downstream of the Platanovrysi dam (Macedonia-Thrace border, northeastern Greece). For attaining the above, two composite mathematical models, each consisting of three submodels, are applied: a rainfall-runoff submodel, a soil erosion submodel and a sediment transport submodel for streams. The two models only differ in the soil erosion submodel. The rainfall-runoff submodel that is used for the computation of the surface runoff and the streamflow in the sub-basins is the deterministic distributed hydrologic model HEC-HMS 4.2. The first soil erosion submodel, utilized for the estimate of soil erosion in a sub-basin, is based on the relationships of Poesen [1985. An improved splash transport model. Zeitschrift für Geomorphologie, 29, 193–211], while the second is the widely known Modified Universal Soil Loss Equation (MUSLE). The estimate of sediment yield at the outlet of a sub-basin, and finally at the outlet of the whole basin, is achieved by means of the stream sediment transport model of Yang and Stall [1976. Applicability of unit stream power equation. Journal of the Hydraulics Division, ASCE, 102 (5), 559–568]. The application of the latter mathematical models results in continuous hydrographs and sediment graphs at the basin outlet. The computed sediment discharge values are compared with field measurements. The statistic efficiency criteria utilized for the comparison between computed and measured values at the basin outlet provide satisfactory results. Therefore, it is concluded that the continuous hydromorphologic modelling can be successfully applied to the Nestos River basin.

A Multialgorithm Approach to Land Surface Modeling of Suspended Sediment in the Colorado Front Range.

A new paradigm of simulating suspended sediment load (SSL) with a Land Surface Model (LSM) is presented here. Five erosion and SSL algorithms were applied within a common LSM framework to quantify uncertainties and evaluate predictability in two steep, forested catchments (>1,000 km2). The algorithms were chosen from among widely used sediment models, including empirically based: monovariate rating curve (MRC) and the Modified Universal Soil Loss Equation (MUSLE); stochastically based: the Load Estimator (LOADEST); conceptually based: the Hydrologic Simulation Program—Fortran (HSPF); and physically based: the Distributed Hydrology Soil Vegetation Model (DHSVM). The algorithms were driven by the hydrologic fluxes and meteorological inputs generated from the Variable Infiltration Capacity (VIC) LSM. A multiobjective calibration was applied to each algorithm and optimized parameter sets were validated over an excluded period, as well as in a transfer experiment to a nearby catchment to explore parameter robustness. Algorithm performance showed consistent decreases when parameter sets were applied to periods with greatly differing SSL variability relative to the calibration period. Of interest was a joint calibration of all sediment algorithm and streamflow parameters simultaneously, from which trade‐offs between streamflow performance and partitioning of runoff and base flow to optimize SSL timing were noted, decreasing the flexibility and robustness of the streamflow to adapt to different time periods. Parameter transferability to another catchment was most successful in more process‐oriented algorithms, the HSPF and the DHSVM. This first‐of‐its‐kind multialgorithm sediment scheme offers a unique capability to portray acute episodic loading while quantifying trade‐offs and uncertainties across a range of algorithm structures.

Soil Erosion and Forests Biomass as Energy Resource in the Basin of the Oka River in Biscay, Northern Spain

The aim of this work has been the development of a methodology for the evaluation of residual forest biomass in Biscay, a province in northern Spain. The study area is located in the Oka river basin, an area of great ecological value qualified by UNESCO (United Nations Educational Scientific and Cultural Organization) in 1984 as a Biosphere Reserve. The project tries to determine the potential, available and usable as energy resource, residual forests biomass, after the treatments of forest species in the area. Soil erosion was modeled using the USLE (Universal Soil Loss Equation) and MUSLE (Modified USLE) methods by estimating rainfall erosivity factor (R), the soil erodibility factor (K), the topographic factors (L and S), cropping factor (C), and the conservation practice factor (P). By means of these models, it will be possible to determine the current soil erosion rate and its potential evolution due to different forest treatments. Soil erodibility, slope of the terrain and the loss of SOC (Soil Organic Carbon) were the restrictive indicators for the bioenergy use of forest biomass, taking into account principles of sustainability. The amount of residual forestry biomass useable for energy purposes has been estimated at 4858.23 Mg year−1.

SWAT Setup with Long-Term Detailed Landuse and Management Records and Modification for a Micro-Watershed Influenced by Freeze-Thaw Cycles

In the widely used soil and water assessment tool (SWAT), the standard hydrological response units (HRUs) delineation method has low spatial resolution with respect to model inputs and outputs and renders difficulties in using long-term detailed landuse and management records. In addition, the modified universal soil loss equation (MUSLE) uses a constant K-factor which cannot address seasonal variation in soil erodibility caused by freeze-thaw cycles in cold regions. The current study presents a simple method to incorporate detailed landuse and management inputs in SWAT. The method delineates HRUs based on field boundaries and associates each HRU with a particular field. As a result, long-term detailed records can be incorporated into the SWAT management files. In addition, the existing MUSLE in SWAT was modified by introducing a variable K-factor to address effects of freeze-thaw cycles on soil erosion for cold regions. This modified version of SWAT was calibrated and validated for an agricultural micro-watershed, i.e., Black Brook Watershed in New Brunswick, Canada. The results showed that, compared with the standard HRU-delineation method, field-based HRU-delineation method was able to improve landuse and management practice input accuracy for SWAT and save time and effort for long-term simulation, and provide high resolution outputs in the watershed. As a result, the field-based HRU-delineation method can facilitate decision making not only at the subbasin scale but also at the field scale. In addition, results showed that sediment loading simulation accuracy was improved with the modified-MUSLE compared with the original-MUSLE.

Testing the USLE-M Family of Models at the Sparacia Experimental Site in South Italy

AbstractThe modified Universal Soil Loss Equation (USLE-M) was empirically deduced by a statistical analysis of the original data set of soil loss measurements used to derive the Universal Soil Los...

Soil erosion susceptibility of Johor River basin

AbstractMalaysia is undergoing tremendous environmental changes due to population growth, economic development and urbanization. This has stimulated a rapid land use changes which in turn has increased the rate of soil erosion and river sedimentation. In this study, Universal Soil Loss Equation (USLE) and the Modified Universal Soil Loss Equation (MUSLE) are applied within a geographical information system (GIS) to assess the spatial pattern of soil erosion susceptibility of Johor River basin, Malaysia. Geomorphological, landuse and soil information along with other hydrological data such as, annual peak flow and runoff volumes are used to estimate the parameters required for the calculation of soil erosion susceptibility. The results show that annual erosion rate varies between 0.2 and 248.2 t/ha/year according to USLE, and between 19.2 and 2179.9 thousand tons per event according to MUSLE. The land cover management is found as the major factor responsible for soil erosion in the basin.

Application of SWAT model for predicting soil erosion and sediment yield

Hirakud, the longest earthen dam in Asia on the river Mahanadi, has been affected by sedimentation problems which affect reservoir storage capacities and different reservoir operations. This article presents the hydrological modeling of the Mahanadi catchment up to Hirakud, located in the states of Chhattisgarh and Odisha in India, using the modified version of Soil and Water Assessment Tool (SWAT) with an interface of ArcView Geographic Information System software to predict soil erosion and sediment transport to the reservoir for improving its useful life. The data sources used in the study were: terrain data 90 m resolution of Shuttle Radar Topography Mission, Land Use and Land Cover derived from Landsat Enhanced Thematic Mapper Plus, soil map published by National Bureau of Soil Survey and Land Use Planning, India and meteorological data collected from India Meteorological Department, India. The study involves the analysis of sensitive parameters of the simulated data (discharge 15, sediment load 6); 5-year calibration and 3-year validation on daily basis to predict the discharge and sediment load. The sensitivity analysis was carried out using the Latin Hypercube and One-factor-At-a-Time. The results also show that the prediction of sediment yield is highly sensitive to the sizes of different sub-basins due to the sensitivity of topographic factors used in the Modified Universal Soil Loss Equation. The graphical as well as statistical results achieved in this study indicate that the model is capable to identify critical erosion-prone areas within the watershed on the scale of sub-watershed which helps the hydrologists to introduce effective management practices at the lowest cost. The study shows that about 34% area of total catchment falls under high or above soil erosion zones with combination of coarse loamy type of soil and agricultural type of land use and land cover condition. The results of this study also identify regions of high sediment yield and sediment delivery ratio. To enhance the SWAT model performance, it is recommended to use sub-daily data and to prioritize soil erosion at the Hydrological Response Units level for improvement of watershed management.

Parameterization of the Effect of Bench Terraces on Runoff and Sediment Yield by Swat Modeling in a Small Semi‐arid Watershed in Northern Tunisia

AbstractIn Tunisia, soil and water conservation interventions are among the most practicable strategies to prevent and mitigate rainwater losses through surface runoff and consequential erosion of fertile soils. In this study, a small and terraced agricultural catchment (Sbaihia) was used as an experimental site to analyze and parameterize the effects of bench terraces on water and sediment yield using the Soil and Water Assessment Tool. Model calibration and validation was performed, taking advantage from high‐quality daily runoff data from 1994 to 2000 and a high‐resolution bathymetric survey of the hill lake at the watershed outlet. Soil and Water Assessment Tool indicated that the local terraces, established on approximately 50% of the watershed area, reduced surface runoff by around 19% and sediment yield by around 22%, decelerating the siltation of the hill lake. Targeted model calibration delivered concise parameter set describing bench terrace impacts on runoff (Soil Conservation Service curve number method) and sediment yield (Modified Universal Soil Loss Equation) crucial for outscaling of soil and water conservation impacts and suitable watershed management. Copyright © 2016 John Wiley & Sons, Ltd.

Estimation of Peak Flow Rates for Small Drainage Areas

Runoff plots are important for soil loss measurements, and increasing numbers of plots use automatic equipment. To choose equipment with appropriate capacities, the peak flow rate must be known. The peak flow rate is also an important parameter in the modified universal soil loss equation (MUSLE) which calculate the soil loss from upland slope. The available peak flow rate equations are primarily for the watershed scale, not for small drainage areas like runoff plot. This study’s purpose was to derive an equation suitable for the small drainage areas. A total of 149 runoff events on 5 runoff plots were used to develop a peak flow rate equation for the hillslope scale. All plots are located in the Tuanshangou catchment, Zizhou county, Shaanxi province, China. Dimensionless analyses were used to determine the equation form of linear regression analyses. The results revealed that the peak flow rate was significantly correlated with plot area, slope steepness, runoff depth, rainfall depth and the maximum 30-min rainfall intensity. Two equations were developed to estimate peak flow. The model efficiencies of both equations exceeded 0.9. The equations developed in this study represent an important complement to existing peak flow rate equations. These new equations will facilitate the design of soil conservation practices and/or the selection of flow-observation equipment for small drainage areas.

A tool for cost-effectiveness analysis of field scale sediment-bound phosphorus mitigation measures and application to analysis of spatial and temporal targeting in the Lunan Water catchment, Scotland

The cost-effectiveness of six edge-of-field measures for mitigating diffuse pollution from sediment bound phosphorus (P) runoff from temperate arable farmland is analysed at catchment/field scales. These measures were: buffer strips, permanent grassland in the lowest 7% of arable fields, dry detention bunds, wetlands, and temporary barriers such as sediment fences. Baseline field P export was estimated using export coefficients (low risk crops) or a modified Universal Soil Loss Equation (high risk crops). The impact of measures was estimated using simple equations. Costs were estimated from gross margin losses or local data on grants. We used a net cost:benefit (NCB) factor to normalise the costs and impacts of each measure over time. Costs minimisation for target impact was done using PuLP, a linear programming module for Python, across 1634 riparian and non-riparian fields in the Lunan Water, a mixed arable catchment in Eastern Scotland.With all measures in place, average cost-effectiveness increases from £9 to £48/kg P as target P mitigation increases from 500 to 2500kg P across the catchment. Costs increase significantly when the measures available are restricted only to those currently eligible for government grants (buffers, bunds and wetlands). The assumed orientation of the average field slope makes a strong difference to the potential for storage of water by bunds and overall cost-effectiveness, but the non-funded measures can substitute for the extra expense incurred by bunds, where the slope orientation is not suitable. Economic discounting over time of impacts and costs of measures favours those measures, such as sediment fences, which are strongly targeted both spatially and temporally. This tool could be a useful guide for dialogue with land users about the potential fields to target for mitigation to achieve catchment targets.

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

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

INFLUENCE OF LAND USE CHANGE ON SEDIMENT YIELD: A CASE STUDY OF THE SUB-MIDDLE OF THE SÃO Francisco River Basin

ABTSRACT Erosion risk mapping and assessment are important for planning of natural resource management tool. The objective of this study was to simulate different scenarios of land use in the Sub-Middle of the São Francisco River Basin using the Soil and Water Assessment (SWAT) model to analyze the effects of changes in sediment yield, making comparisons with the present land use classification. The scenario analysis was (i) vegetation type characteristic of the semiarid region, (ii) growing corn and (iii) bare soil. For calibration procedure, the first three years of time series from 1993 to 1994 were validated using data from 1995 to 2004. The SWAT model employs the Modified Universal Soil Loss Equation (MUSLE) to compute soil erosion data. The results of simulations for different land uses allowed the identification of areas with a high potential for erosion by water. The major impact produced by sediment inflow was in the bare soil scenario, corresponding to an increase of 93.7% over the current land use. The landscape management in river basins using SWAT model can help identify areas particularly susceptible to erosion process.

In-between forest expansion and cropland decline: A revised USLE model for soil erosion risk under land-use change in a Mediterranean region

The present study illustrates an original approach for the long-term assessment of soil erosion risk under land-use changes in a Mediterranean region (Matera, southern Italy). The study has been focused on the implementation of a modified Universal Soil Loss Equation (USLE) model at three time points (1960, 1990, 2010) with the objective to evaluate the contribution of each component to model's performance and model outcomes’ reliability. A modified USLE model was proposed for the assessment of soil erosion risk, based on the simplification of model’s parameters and the use of high spatial resolution datasets. Spatio-temporal variability in the model's outcomes was analyzed for basic land-use classes. Our approach has improved model's flexibility with the use of high spatial resolution layers, producing reliable long-term estimates of soil loss for the study area.

Sediment yield assessment and identification of check dam sites for Rawal Dam catchment

Sediment yield is the amount of erosional debris from drainage basin deposited in reservoirs. The economic life of storage reservoir depends upon the estimation of the time it takes for the reservoir to be filled with the deposition of sediments. This research is based on assessing the sediment yield in Rawal Dam catchment by using Soil and Water Assessment Tool (SWAT) model. Digital Elevation Model (DEM), land use maps, soil maps, and weather data of the study watershed were used as input to SWAT model. Monthly sedimentation data of year 2010 and discharge data from 1998 to 2005 is being used for model calibration and validation, respectively. Whereas simulations are being generated from 1998 to 2011 for both sedimentation and discharge. Modified Universal Soil Loss Equation (MUSLE) was used for the estimation of sediment yield. The Nash and Sutcliffe coefficient of the model was found to be 0.79 which depicts its effectiveness. After the estimation of the sediment yield and discharge by using SWAT model, double mass curve was used to evaluate the sedimentation rate. The rate of sediment transport can be reduced by the construction of check dams. Various sites have also been proposed for check dams construction to prevent the sediments transported into the Rawal Catchment.

Land use changes and sediment yield on a hilly watershed in Central-East Argentina

Watershed management strategies need suitable techniques to be available in order to quantify sediment yield, among other relevant issues. The aim of this work was to estimate the sediment yield on a hilly watershed, for two different land use scenarios (years 1966 and 2011) and rainfall events (106 mm and 65.5 mm). The Modified Universal Soil Loss Equation was used to estimate the sediment yield produced by a single rainfall on the watershed of the Belisario Creek, placed south-west of the Buenos Aires province, Argentina. The information was processed using the Geographic Information System Idrisi Taiga®. Modelling the 45-year distant land use scenarios allowed to estimate the high level of degradation that is currently taking place on the watershed. Also, we detected different responses through different areas of the watershed; the same rainfall event in the 2011 land use scenario compared to the 1966 scenario showed a 400% increment in sediment yield in the upper sub-watersheds, together with an almost 100% increment near the sink. Here we propose the urgent need to elaborate a sustainable plan for the watershed of the Belisario Creek, in order to establish action criteria that could help improve natural resources management. The methodology used could be also applied to neighbouring watersheds with similar characteristics in the region.

Adapting SWAT hillslope erosion model to predict sediment concentrations and yields in large Basins

The Soil and Water Assessment Tool (SWAT) is used worldwide for water quality assessment and planning. This paper aimed to assess and adapt SWAT hillslope sediment yield model (Modified Universal Soil Loss Equation, MUSLE) for applications in large basins, i.e. when spatial data is coarse and model units are large; and to develop a robust sediment calibration method for large regions. The Upper Danube Basin (132,000km2) was used as case study representative of large European Basins. The MUSLE was modified to reduce sensitivity of sediment yields to the Hydrologic Response Unit (HRU) size, and to identify appropriate algorithms for estimating hillslope length (L) and slope-length factor (LS). HRUs gross erosion was broadly calibrated against plot data and soil erosion map estimates. Next, mean annual SWAT suspended sediment concentrations (SSC, mg/L) were calibrated and validated against SSC data at 55 gauging stations (622 station-years). SWAT annual specific sediment yields in subbasin reaches (RSSY, t/km2/year) were compared to yields measured at 33 gauging stations (87station-years). The best SWAT configuration combined a MUSLE equation modified by the introduction of a threshold area of 0.01km2 where L and LS were estimated with flow accumulation algorithms. For this configuration, the SSC residual interquartile was less than +/−15mg/L both for the calibration (1995–2004) and the validation (2005–2009) periods. The mean SSC percent bias for 1995–2009 was 24%. RSSY residual interquartile was within +/−10t/km2/year, with a mean RSSY percent bias of 12%. Residuals showed no bias with respect to drainage area, slope, or spatial distribution. The use of multiple data types at multiple sites enabled robust simulation of sediment concentrations and yields of the region. The MUSLE modifications are recommended for use in large basins. Based on SWAT simulations, we present a sediment budget for the Upper Danube Basin.

Suitability of revision to MUSLE for estimating sediment yield in the Loess Plateau of China

This study evaluated the effect of a combination of revisions to the cover and management factor (C), support practice factor (P), and topographic factor (LS), and to determine the best use of each combination for modified universal soil loss equation (MUSLE) being applied in the Loess Plateau of China. Eight combinations were built based on common local methods of revision to factors C, P, and LS in three ways (single factor revised, two factors revised, and three factors revised, respectively). By validating the effect of these combinations on sediment yield estimation using the Nash–Sutcliffe coefficient of efficiency (NSE), normalized root-mean-square error (NRMSE), correlation coefficient (R), and angle between liner trend line and 1:1 line, the optimal combination was selected. Results show that: (1) the original method significantly overestimates the sediment yield; (2) when revising a single factor, the LS factor revision has the greatest positive effect; (3) when revising two factors, the combination of a simultaneous revision to C and to P has the smallest angle between the liner trend line and the 1:1 line (1.37°); if the estimating accuracy of sediment peak is required, this combination may thus be a useful approach; and (4) when revising C, P, and LS simultaneously, the combination has the highest NSE (0.76), lowest NRMSE (1.19), and the highest correlation coefficient (0.760), and may be used to estimate sediment yield. The suitability of MUSLE is enhanced using the common local revision to factors C, P, and LS. Under the assumption that level terrace spatial information can obtain effectively (or that there are few level terraces), these findings can be applied to the Loess Plateau for the design of soil and water conservation measures and for flood disaster assessment, and applied to future model applications in the Loess Plateau.

Predicting characteristics of rainfall driven estrogen runoff and transport from swine AFO spray fields

Animal feeding operations (AFOs) have been implicated as potentially major sources of estrogenic contaminants into the aquatic environment due to the relatively minimal treatment of waste and potential mobilization and transport of waste components from spray fields. In this study a Bayesian network (BN) model was developed to inform management decisions and better predict the transport and fate of natural steroidal estrogens from these sites. The developed BN model integrates processes of surface runoff and sediment loss with the modified universal soil loss equation (MUSLE) and the soil conservation service curve number (SCS-CN) runoff model. What-if scenario simulations of lagoon slurry wastes to the spray fields were conducted for the most abundant natural estrogen estrone (E1) observed in the system. It was found that E1 attenuated significantly after 2months following waste slurry application in both spring and summer seasons, with the overall attenuation rate predicted to be higher in the summer compared to the spring. Using simulations of rainfall events in conjunction with waste slurry application rates, it was predicted that the magnitude of E1 runoff loss is significantly higher in the spring as compared to the summer months, primarily due to spray field crop management plans. Our what-if scenario analyses suggest that planting Bermuda grass in the spray fields is likely to reduce runoff losses of natural estrogens near the water bodies and ecosystems, as compared to planting of soybeans.

Analysis and simulation of large erosion events at central Texas unit source watersheds

Summary This study uses long-term daily sediment records (12–51 years) from 5 unit-source watersheds in central Texas to examine the role of large infrequent erosion events in the makeup of the overall soil loss record. Additionally, multi-decadal daily erosion simulations with the Soil and Water Assessment Tool (SWAT) using both the Modified Universal Soil Loss Equation (MUSLE) and physics based erosion routines are conducted to assess the routine’s ability to predict extreme events and long-term budgets. The empirical record indicates the upper 10% of erosion events (in terms of mass) comprise roughly half of the long-term soil loss sum. These upper end events are characterized by large unit flow erosion values and not necessarily associated with precipitation or runoff extremes. The two SWAT routines showed little differences in total soil loss masses; however, the distribution of soil loss events from the physics based simulation, including upper end events, more closely resembled the empirical record than the MUSLE prediction.