Abstract:
The present study demonstrates a spatially distributed application of a field-scale annual soil loss model, the modified-MMF (MMMF), to a large watershed using hydrological routing techniques, remote sensing data and geospatial technologies. In this study, the MMMF model is implemented after incorporating the corrections suggested in recent literature along with appropriate modifications of the model to suit the agro-climatological conditions prevailing in most parts of India. Sensitivity analysis carried out through an Average Linear Sensitivity approach indicates that the model outputs are highly sensitive to soil moisture (MS), bulk density (BD), effective hydraulic depth (EHD), ground cover (GC) and settling velocity for clay (VSc). During calibration and validation, the performance evaluation statistics are mostly in the range of very good to satisfactory for both runoff and soil loss at the watershed outlet. Even spatial validation of the results of intermediate processes in the water phase and the sediment phase, although qualitative, seems to be reasonable and rational. Furthermore, the soil erosion severity analysis for different land-uses existing in the watershed indicates that about 90% of the watershed area, especially that occupied by agricultural lands, is vulnerable to the long-term effects of soil erosion. Copyright (c) 2018 John Wiley & Sons, Ltd. Highlights of the study Implements the MMMF model, a field scale soil erosion model to a large watershed. Provides a framework for implementation of the MMMF model at watershed scale. Improves the MMMF model to suit Indian climatic conditions. Point based quantitative tests show acceptable performance of the MMMF Model.