Analisis resiko iklim di das citarum hulu akibat perubahan iklim dan penggunaan lahan

Abstract

This research was conducted in Upper Citarum Watershed, West Java province with total area of 172,046 ha, from May to November 2012. The main objective of this study was to assess the effect of climate and land use changes on current and future flood risk in the upper watershed. The assessment was done using dynamic simulation model called Soil Water Assesessment Tool (SWAT). The SWAT model was calibrated using observation data from January 2001 to December 2002 and validated using observation data of 2003 and 2004. Calibration process were done using SUFI. The SUFI-2_SWAT CUP adjusted 20 parameters of the model consisting of streamflow, groundwater, main channel, hygrograph response unit, landuse management and soil parameters that provide the maximum correlation value between observation and simulation. The result of validation of the calibrated model provided Nash-Sutcliffe Efficiency (NSE) of 0.773 with R2 0.771 indicating the model is reliable to be used for further assessment. The assessment used land use 2000, 2010 and land use projection up to 2025 assuming the pattern of land use change following historical pattern. The percent forest cover under the three landuses was 42%, 34% and 26% respectively. The result of the assessment indicated that the land use influences the flood risk. The land with less forest cover would be exposed to higher flood risk. Under land use of 2000, the return period of having heavy flood was once in 14 years, under land use of 2010 and 2025, it increased to once in 13 and 10 years respectively. Climate change would increase flood risk. Under land use of 2010, the return period of flood risk will increase from once in 13 years to once in 5 years.