Sistem pendukung keputusan keruangan untuk analisis kerentanan akibat kenaikan muka air laut dan amblesan tanah di Kota Semarang

Abstract

The relatively flat topography of Semarang has caused this city is vulnerable to sea level rise phenomenon. Various environmental problems faced by the city associated with coastal and ocean dynamics are tidal inundation, land subsidence, and flooding in rainy seasons. This study was conducted to (1) develop a spatial dynamic model of inundated areas due to sea level rise (2) map the coastal vulnerability due to sea level rise and land subsidence (3) prepare adaptive strategy to solve those environmental problems. Flash technology was used to model spatial dynamic distribution of inundated areas due to sea level rise. IPCC scenario at pessimistic and optimistic scenarios were combined with rate of land subsidence rates to predict an inundated scenario at the year of 2030. Adaptation strategy was developed by considering coastal vulnerability and adaptive capacity of the areas. Study results showed that the inundated areas at the year of 2010 were 1,231 hectares. Pessimistic sea level rise and land subsidence scenario showed that the size of inundated coastal areas of Semarang was 1,718.2 hectares, while pessimistic scenario showed an increasing inundated areas to 5,171.3 hectares. Fish-pond was the most extensive land use in coastal areas, as well as the most vulnerable areas to inundation. The inundated fish-pond areas in 2010 were predicted 272.8 hectares which would increase to 913.6 hectares in 2030. Potential losses derived from inundated areas would increase from IDR 3.7 T in 2010 to IDR 28.7 T in 2030. Adaptive capacity of villages in Semarang in 2010 was relatively high with low vulnerability level to inundations, whereas vulnerability level in 2030 tended to increase along with the extensification of inundated areas.