Impacts of Urban and Industrial Development on Groundwater, Bandung, West Java, Indonesia^*)

by : Soetrisno S.^**)

 

Change of Recharge

Urbanization and industrial development has changed land-usage of the Greater Bandung. Increasing population due to its natural growth and migration needs more land for providing houses.

Land which formerly was paddy field, bare land or as open space has changed to densely populated residential compound. And it is often that new residential area occupied the hilly area surrounding the basin, where is considered as primary recharge area.

There is no industrial estate in the Greater Bandung, actually. Factories are mostly located scattered in the plain area. Since it needs many employees, the existing of the factories attracted people to live nearby and build houses. Then, area enclosed to the factories growing to be residential compound, locally knows as "kampung", high density population in generally one storey building. It used more land rather than multi storey building.

Present urban land use (settlement, housing and industrial areas) as result of those development occupies 9 % of the total area of the basin, while paddy field, both irrigated and rained fed, still occupies the largest portion of the basin about 34.3 % (Hoffmann, et al, 1990), although it has changed many to the urban areas, particularly in the low plain of the basin for nearly last three decades..

Since more land has been being occupied by housing complexes, business districs, and industrial areas, it changed the recharge potential to the aquifer system in the basin. Up to now there is no evaluation in comparison between pre and post urban recharge in the greater Bandung. However, referring to Foster, et al, 1994, and Sunjoto, 1996 (personal communication) which calculated post urban recharge in volcanic product is 1.4 greater than pre urban recharge, post urban recharge in the Bandung basin might be greater than pre urban recharge, particularly in the northern part of the basin. In the flat plain area which occupied by dense urban areas, groundwater recharge might be decreased while surface run-off increases, which is proved by extending of flood prone area every year, since 1980. Extension of flood prone area in the Bandung basin was 571 ha in 1980 and 3,358 ha in 1994, while in the same period Citarum river flow in the Nanjung gauging station, southwest of the basin, was recorded 220 and 374 m³/sec respectively (Anonymous, 1996).