Redesigning the Morgan-Morgan-Finney Soil Erosion Model for Global High-Resolution Application

Abstract

The Morgan-Morgan-Finney (MMF) model is identified as the most appropriate hillslope soil erosion model for high resolution global application with the objective of identifying relative erosion risk areas and modelling the effect of land cover changes on erosion at a catchment scale. This is justified by its simple model structure, low input requirements, semi-empirical basis and distributed application. However, transferability to global application is hindered by its reliance on empirical data for input requirements. This paper proposes methodologies of generating input data based on remotely sensed products which improves the spatial and temporal accuracy of the input rasters. The MMF model is further redesigned by coupling it with the IHE Delft Institute for Water Education inhouse hydrological model, WaterPix, to replace runoff calculations in order to improve its treatment of infiltration and by applying the model in monthly timesteps to analyse erosional differences within the seasonal crop calendar. The redesigned MMF model algorithm is coded in python and applied over a headwater in the Ganga basin located in the Madhya Pradesh state of India. The model produces realistic erosion rates and distributions and provides additional information on the spatial and temporal variation of erosion in the study area. However, validation of the redesigned model with field data needs to be prioritized before it is utilized.