GIS and RS Based Soil Erosion Modelling in Sri Lanka: A Review.

Purpose: Over the seventy years, various soil erosion modeling methods were developed in the world with different input requirements and complexity. Some of these soil erosion models have been applied in Sri Lanka covering several regions of the country at different scenarios over the past twenty years. Thus, the prime objective of this study is to compare commonly practiced GIS/RS based soil erosion assessment models and derivation techniques of model parameters used in Sri Lanka. Research Method: Scholarly research articles, conference proceeding papers, and previously published literature on GIS/RS based soil erosion models over the past twenty years were critically reviewed, examined, and compared to find various methodologies in the derivation of soil erosion model parameters, analysis methods, and applications with special reference to Sri Lanka. Findings: The results revealed that, in each case, the empirical soil erosion models have been applied to predict soil erosion rates in terms of rill and sheet erosion excluding gully erosion. Furthermore, soil loss at the catchment or entire country scale has been assessed in each case by using different derivation methods. The assessed soil erosion model parameters are R factor (rainfall erosivity), K factor (soil erodibility), LS factor (slope gradient), C factor (crop management factor), and P factor (support practice factor). Originality/Value: Different derivation methods of soil erosion model parameters (R, K, LS, C, and P) were critically evaluated in order to find the most appropriate methods that can be applied in Sri Lanka in future research studies. [ABSTRACT FROM AUTHOR]