Analysis of Flood Hydrograph to the Land Use Change on Flood Peak Discharge in the Sekanak Watershed

Abstract

Land demands in urban areas are increasing with urbanization. To supply the urban land demand, various method are made including the over land function. The over land function if not properly planned will result in increased run-off in a watershed. The increased surface runoff will increase peak discharges and potentially cause flooding when capacity storages such as drainage and retention basins, as well as other low areas such as open areas and swamps are full. The effect of land use on peak discharge is a question that needs to be analyzed. The purpose of this study is to assess land use change and analyze peak flood discharge in the upstream of Sekanak watershed. The research methodology uses is spatial analysis that is doing DEM (Digital Elevation Model) analysis to determine river flow limit and determining of watershed characteristics and analysis of land use change in year 2004 and year 2014 influence to flood peak discharge in Sekanak watershed, due to rainfall factor. Peak discharge analysis was conducted with Nakayasu Synthetic Unit Hydrograpah. The result of this study is land use change increases the coefficient C value, causing the peak discharge in the 5 year return period to increase.