Application of Geographic Information System (GIS) for Hypsometric Analysis of a Bicol River Basin Area

Hypsometric analysis was employed to assess the erosion status of watersheds. This is necessary to check erosion, conserve water and to implement better land management practices. This study applied the Geographic Information System (GIS) to conduct a hypsometric analysis in a vital source of surface water of Bicol River Basin particularly the Lake Buhi catchment area. Significantly, the fundamental hypsometric parameters were described. The proportions of altitude to a particular land area using the hypsometric integral (HI) was illustrated. It was concluded that application of GIS was instrumental to describe the different topographic features such as the erosional, residual and depositional features reflected in the contour and hill shade maps.  It was found that the area proportion is decreasing while the elevation interval is increasing. The hypsometric curves are at old dissected, eroded landscape except for P-1 that exhibits maturely dissected landform. The HI reflected that they are at old dissected, eroded landscape. The result of this study may be considered for several applications: it will serve as an aid in the implementation of necessary measures to conserve water and soil resources for the catchment's long-term development; the approach presented may be used in assessing other river basin for the initial characterization; practical applications are foreseen in hydrology, soil erosion and sedimentation studies; it may be used for understanding the stages of geomorphic development of other river basin; it may be used in prioritizing watershed for planning engineering measures and to mitigate the impact; the GIS approach may be used to obtain hypsometric information and in enabling the hydrologic modelling community.