Philippine E-Journals

Land Cover Changes and Flood Dynamics in the River Basin of Tanay, Rizal, Philippines

Romeo C. Pati

 

Abstract:

The interaction of land cover changes and the flood were examined using simulation and land cover change analysis. Hydraulic Engineering Center – River Analysis System was used to simulate the flood flow using the derived hydrograph under different land cover scenarios in the flood plain of the river. The hydrograph of the river networks were simulated using rainfall data and watershed characteristics as input to the Hydraulic Engineering Center –Hydrologic Modelling System. The model was calibrated using the measured water depths and discharge of the river cross-section. The watershed is dominantly covered by orchard plants and grasses with an area of about 2286.68 and 1157.4 ha, respectively. Flood simulation predicted the flood depths and delineated the spatial extent of flooding in the flood plain of the river for the different land cover. Approximately 16.4 ha can be saved from flooding if the grasslands in the upper portion of the watershed are reforested. The major environmental adaptive measures that need to be done are the development of a comprehensive community-based rehabilitation and management of Tanay watershed and the protection of the remaining watershed of the area.