The projected coastal flooding in Semarang low land under chronic pressures J W Nugroho, L Anzani, L O A Minsaris, J Risandi and H Rifai
Department of Marine Information System, Indonesia University of Education (UPI) Jl. Dr. Setiabudi No.229, Bandung, Indonesia
Research Center for Oceanography, National Research and Innovation Agency (BRIN), Jakarta 14430, Indonesia
Abstract
Coastal flooding has become the main hazard in most coastal cities, including Semarang, the capital of Central Java Province, Indonesia. The flooding periodically inundates the city causing huge loss and damage to the environment and socioeconomic. In the coming decades, the vulnerability of the Semarang region will increase due to pressures from high tides and rapid sea level rise (offshore), as well as land subsidence (onshore). Hence, future estimates on the potentially inundated area across the city are critical to developing adaptive measures. We applied a set of global data from Tide Model Driver (TMD), Hybrid Coordinate Ocean Model (HYCOM), and Sentinel-1A to quantify the increase of seawater level in Semarang. Furthermore, the current and future coastal flood hazards (25 to 100 years) for Semarang were generated based on the national Digital Elevation Model, the DEMNAS. The study highlights the increase of flooding risk in Semarang due to the increase of seawater level and exacerbating land subsidence, mainly in the lowland area that may be severely inundated by more than 1.5 m. Considering the importance of Semarang as the main city in Central Java, future development of the city needs to include measures to minimize the impact of flooding
Keywords: Coastal flooding, land subsidence, prediction, sea level rise, Semarang, tides.
