Water Balance Estimation Of Selected Land Cover In Taganibong Watershed, Bukidnon Using GEOWEPP Model

The Geospatial Water Erosion Prediction Project (GeoWEPP v10.2) was tested using data from field survey in three study site within Taganibong Watershed, Bukidnon. This field survey data such as waypoints and soil data was processed and edited through ArcGIS software to prepare for model simulation. Weather information were collected using Automatic Weather Station on an hourly basis at the study site. Climate data was created using Breakpoint Climate Data Generator (BPCDG) which allows direct use of observed storm and other daily standard climate datasets.

Model simulation was applied in three land cover to evaluate their abilities in reducing runoff and their effects on other water balance parameters. For the study area, the bamboo area with undisturbed harvesting practices has more effective way in reducing surface runoff based on the results of model simulation. On the other hand, the cultivated area (corn) produce highest surface runoff due to the exposure of soil after harvesting period.

Statistical analysis was applied to determine the effects of different land cover to the amount of water balance given the amount of rainfall in monthly basis. Magnitude of rainfall as the primary input to water balance has a huge effects in return to hydrologic processes (percolation, soil water, subsurface lateral flow, etc). This study provides a theoretical basis and technical support for land use zoning, policy implementation, soil and water conservation in upland watersheds.