A GIS Model for Predicting Disaster Prone Areas Affected by Global Sea-Level Rise: a Case Study of Semarang City

Abstract

The issue of global warming that increases sea level will certainly have an effect on sustainability of coastal areas, including coastal cities. Some studies predict that in 2050 the potentially flooded areas around the world will increase approximately one to three meters (WOC, 2007). This tendency will in turn influence the sustainability of many Indonesian cities, particularly those located on coastal areas. Regarding the above issue, this research aims at developing a spatial model using Geographic Information System (GIS) for predicting/delineating disaster prone areas in coastal cities. The model involves some GIS analysis’ capabilities, such as spatial overlay, weighting method and spatial query to delineate flooded areas based on the increase of global sea level and its topography. To test the developed model, Semarang City is selected as the case study with consideration that some previous researches have been done in this area so that most of required data have been collected. The model is then validated using empirical data and field visits to compare between the result and the current situation. The result of application shows that the developed model is satisfied. As for the case of Semarang City, the result shows that 71.6 km2 of Semarang coastal areas are potentially flooded, which 5.04 km2 are highly risk. By superimposing the potentially flooded areas and some vulnerability aspects, the model delineates disaster prone zones as high, moderate and low level. In spite of the fact that the model development purpose is accomplished, further studies are still needed, particularly to specify variables of vulnerability due to the Characteristics of the city. Besides, a 3D model can also be combined with the developed model to improve its visual view