Land Use and Surface Runoff Change in Babon Watershed Semarang Greater Area

Abstract

Babon is a watershed in Central Java that passes through the Semarang Regency, Semarang City, and Demak Regency. Most of the areas in Babon Watershed are potential residential locations for the community because they are situated on the outskirts of Semarang City. Over the past 20 years, Babon Watershed has experienced a change in land use from agriculture and plantations to residential areas. There have also been flooding incidents in several housing areas along the Babon River. The Semarang City Government currently focuses on developing watersheds in the central and western parts. However, no government intervention has yet to develop the eastern watershed, especially the Babon watershed. Babon watershed management is tricky because three regions pass it, so good governance collaboration from the government and related stakeholders is essential. Therefore, the research aims to assess land use and surface runoff change in the Babon watershed. The research method is quantitative. Data collection methods are secondary data collection and field observations. Data analysis methods are spatial analysis using Geographic Information Systems to determine land use changes and the infiltration areas in the Babon watershed in 2013 and 2023; also analysis of surface runoff water discharge using the rational method. Based on the research results, the Babon watershed has experienced significant changes in land use, with non-developed areas being transformed into developed lands. The increasing transformation from non-developed to developed lands impacts water infiltration areas.