MODEL HIDROLOGI DAS ITN I

Abstract

Physical spatial factors of watershed such as topography, soil types and land use show a prominent
contribution in the distributed water shed modeling. One of the difficulties encountered is the change of
topographical information in map form into data that can be read by model program. In the process of
analyses, physical spatial factor of water shed is divided into grid system consisting of rectangular cells
groups. In each cell, surface run off discharge ,including its direction, is determined based on the depths by
applying a one dimension unsteady flow concept whereas direction is determined by using information on
four points of the cells. Water depth of the surface run off can be calculated by using both a vertical water
movement model and land use area condition. The model has been tested using the available data of Lesti
(East Java) watershed. From calibration and verification processes, this so called Hydrological Model of
ITN 1 has been successfully applied with very good reliability.