ACCURACY OF MAPWINDOW AND SWAT WATERSHED MODEL IN SIMULATING HYDROLOGIC CHARACTERISTICS OF CISADANE WATERSHED, WEST JAVA INDONESIA

Abstract

ABSTRACT
Pressure of population growth has induced land use change around Cisadane Watershed. Land use
change in this watershed had caused negative effects on the hydrological characteristics of the watershed, To
be able to predict impact of land use on hydrologic characteristics of the watershed in the future, a tool is
required. Combination of Map Window and SWAT Watershed Model were tested for this purpose. The
research objectives were 1) to examine the accuracy of MapWindow and SWAT in delineating the subwatershed
boundary compared to existing maps, and 2) to determine accuracy of MapWindow and SWAT in
simulating river discharge based on a particular land use in Cisadane Watershed.
Research was carried out in two steps, these are geographic data processing using MapWindow-
SWAT and determination of model prediction accuracy. Level of prediction accuracy was determined using
Nash-Sutcliffe coefficient. Boundaries of sub-watersheds were delineated using DEM map from SRTM
(Shuttle Radar Topography Missions) Z_58_14. tiff with 90x90 m resolution. Land use map was derived
using Landsat TM image path 122 row 064 and row 065.
Sub-watershed boundaries that were delineated using MapWindow and SWAT showed 90 % accuracy
with existing maps with some deviations in the lower part of the watershed where topography was quite flat.
Higher resolution of DEM map would give better result. Combination of MapWindow and SWAT were able
to predict river discharge giving Nash-Sutcliffe coefficient of 0.7. This coefficient showed a good performance
of MapWindow and SWAT in predicting river discharge in Cisadane Watershed. With this performance,
combination of MapWindow and SWAT can be used to predict future impact of land use change on hydrologic
characteristics in Cisadane Watersheds.