Abstract

Integration of GIS in Soil Erosion Modelling for Magat Watershed
Track: Environmental Management
Authors: Matthew Oliver Ralp Dimal

Soil erosion is an environmental and economic problem persisting in many provinces of the Philippines. This study provides a framework to assess annual soil loss and sedimentation occurring in an important watershed in the Philippines - the Magat Watershed. Spanning 420,000 hectares, this watershed is utilized in various economic activities such as agricultural production, irrigation, and power generation. By integrating GIS and RS with empirically-based approaches, this paper offers an approach in estimating and analyzing soil loss and sedimentation in the reservoir. This will provide the stakeholders the dynamic hydro-geomorphological processes within the watershed to assist in strategic planning and management. The gross soil erosion was estimated to be 15.125million-tons-per-year, or about 35.69 tons/hectare/year. This corresponds to 0.297cm of soil loss annually, which could deplete Magat's effective soil depth in about 250years. Results show that the developed methodology is useful in estimating soil loss and sediment yield in a watershed.