Soil erosion assessment using MMF model and geoinfomations in small watershed

Abstract

In the present study, Modified Morgan Morgan and Finney (MMF) model is used to assess soil erosion rate. Land use and land cover map was derived from Landsat TM data of 2014. The soil group map from Land Development Department was used. The slope map was from ASTER GDEM data. Rainfall data of Thai Meteorological Department which lies within watershed has been utilized. In MMF model, parameters such as annual rainfall, soil moisture content at field capacity, bulk density, effective hydrological soil depth, soil detachability index, slope, interception capacity, canopy cover, ground cover, plant height, crop cover management factor and ratio of actual and potential evapotranspiration was derived for soil erosion computation. In the present study, Huai Ban Bo sub-watershed which is located in Suanphueng district, Ratchaburi province, Western of Thailand has been taken as study area. The results show that, average kinetic energy is 28.10 J/m2. The average detachability by raindrop is 0.0076 kg/m2. The average detachability by runoff is 0.63 kg/m2. The average annual soil detachability is 0.64 kg/m2. The average transport capacity by runoff is 2.31 kg/m2. Average annual soil loss of 0.64 kg/m2 in Huai Ban Bo sub watershed has been estimated.