The recent rapid population and economic growth in Southeast Asia has brought about drastic socio-economic changes, such as urbanization and an agricultural shift. Urbanization consists of concentrating a population from a rural to an urban area and expanding urban areas, which pushes farmland outward. The current development diagram generates and accumulates disaster risk as an extensive risk; however, the relationship between developmental progress and the increase in disaster risk must be determined for sustainable development to be achieved. We assessed the effects of land-use changes driven by economic growth on sedimentation in a river reach of the upper Citarum River basin in Indonesia. The land-use changes in the 20 years from 1990 to 2010 were driven by economic growth and urbanization around Bandung city and are typical for Southeast Asia. Urbanization was characterized by expansion of the urban area, replacement of paddy fields, and cultivation of forest into upland fields for cash crops. As a result, sediment runoff from the hillside to the plate increased from 0.17 Mton /year to 0.24 Mton /year, and sediment deposition on the plate increased from 0.11 Mton /year to 0.13 Mton /year. This amount corresponded to about 30% of the sediment dredged for flood control in 2013. These results indicate that the land-use changes had a direct impact on humans under the heavy rainfall and a wide plate with steep hillside characteristics of Southeast Asian islands. We revealed the relationship between developmental progress and increased disaster risk. The results suggest that forest cultivation and the increased flood risk in the urban area were directly connected through land-use driven by rapid economic growth and urbanization.
Authors and Publishers
Noda, K., the University of Tokyo, Meguro-ku (Japan). Insutitute of Industrial Science