MODEL LAND COVER INDEX – PEAK DISCHARGE IN MANAGEMENT OF RIVER BASIN

Abstract

A change of the characteristic of a river basin’s component could transform the behaviour of
the basin as a whole. In some parts of Indonesia, the land-use changes from forest into settlement, industry,
and farming increase the risk of flooding. Therefore, it is important to understand the correlation between the
changes of various land uses and runoff discharge in a river basin. This study makes an attempt to formulate
the relation between the land-use change indexes and run-off discharge, i.e. the correlation between the
changes in the index of covered land in a river basin and the change in the peak run-off discharge. The peak
discharge is computed with HEC-HMS software, developed by the Hydrologic Engineering Center (HEC)
and US Army Corps of Engineers, which computes the run-off discharge from the precipitation. As for the
land cover index (LCI), it is defined as the sum of the land-use index (LUI). The result of the case study in
the Beringin river basin (Indonesia) shows the strong correlation between the change in the land cover index
and the change in the run-off discharge with such a relation: DQ = -4E - 05 DLCI2 + 0.0788 DLCI + 6.6187
or DLCI = 0.25 DQ2 + 6.24 DQ - 47.40. DQ is defined as the change in the run-off discharge and DLCI is the
change in the land cover index.