Assessing Flood Vulnerability in Jakarta: A Case Study of the 2007 Flood Using the J2000 Hydrological Model in the Katulampa Sub-Basin

Abstract The reconstruction of the 2007 Jakarta flood using the J2000 hydrological model focuses on the Katulampa sub-basin, a critical area for early flood detection in Jakarta’s lowlands. This study integrates meteorological, topographical, and hydrological data to simulate daily runoff patterns and analyze flood dynamics. The model effectively captured seasonal variability and extreme events, achieving Nash-Sutcliffe efficiencies of 0.60 and 0.81. Results indicate that extreme precipitation, peaking at 122 mm/day during the 2007 flood, was the primary trigger, significantly exceeding seasonal averages. Overland flow, driven by soil saturation and sealed surfaces, accounted for 89% of the total runoff, highlighting the influence of land-use changes on flood vulnerability. The research underscores the critical role of upstream monitoring at the Katulampa gauging station in providing early warnings, enabling timely mitigation measures before floodwaters reach Jakarta’s lowlands. This study demonstrates that hydrological models like J2000 are indispensable for understanding and predicting water movement in flood-prone urban areas. The findings emphasize the necessity of integrating hydrological modeling with urban planning and flood management strategies to enhance Jakarta’s resilience to climate-induced extreme weather events and land-use changes.