Soil erosion assessment using revised Morgan, Morgan Finney model for prioritization of Dhanikhari watershed in south Andaman

Natural resources of Andaman Islands are constrained due to anthropogenic interference in the form of farming on slopes and deforestation which causes accelerated erosion. Assessment and mapping of erosion prone areas facilitate soil conservation and watershed management. This study used revised Morgan, Morgan and Finney model (RMMF) to assess spatial soil erosion risk at field plot and watershed scale with the aid of remote sensing and GIS. The model was calibrated using field plot observations and the model predicted soil loss was close to the observed value (R² = 0.9). The results indicated that the annual average soil loss from Dhanikhari watershed was 25.29 t/ha and total soil loss was 27,142 tonnes. The model predicted relatively higher soil loss under agriculture especially under plantation crops in the higher slopes. The estimated annual soil loss rates were classified into six severity classes and the majority of the watershed falls in very low priority category followed by low, very high and high.