(1)Donny Harisuseno,(1)Mohammad Bisri, (2)Adipandang Yudono
(1)Department of Water Resources Engineering, University of Brawijaya, (2) Department of City and Planning, University of Brawijaya, Indonesia
The change of landcover from pervious area into impervious area in urbanized area give an impact on the increasing of runoff depth and directly will cause flood and inundation area. The purpose of this research is to propose an effective method for estimating spatially distribution of runoff depth in order to to promote the spatial planning development. The research location was in the Klojen Sub District, located in Malang Municipality, East Java Province. The procedure analysis of runoff depth distribution in this research was performed by using hydrology model KINEROS based Geographical Information System (GIS). The model simulation was run based on the input of daily maximum rainfall and for each landuse 2006 and 2010. The outputs of the model were calibrated and verified by comparing the model results with field observation at each land utilization. The calibrated runoff model was used to simulate the runoff depth for other rainfall depth in order to know respon of runoff in regard with rainfall. The result showed that runoff depth distribution map in the study area greatly influenced by rainfall intensity and landuse type. The increasing of impervious area about 45% on 2010 cause increasing in the runoff depth in the study area. The highest of runoff depth in the study area was produced based on landuse year of 2010 where the depth of runoff showed 139.8mm, located in Penanggungan Village. Further, the result of the study also showed that some parameters closely influenced runoff yield, namely rainfall intensity, landuse type, and soil type. These results could be used as supporting information in the decision support system regarding the spatial planning and management in urbanized area, especially in the determination of water conservation area.
Keywords: runoff depth, hydrology model, landuse