Decreasing the surface run-off through the rainfall absorption in Bandung Basin

Abstract

Expansion of built-up area was increasing the surface run-off. This research conducted in Bandung basin and aims to analyzing land use change, volume of rainfall that was not absorbed by built-up area and the attempts to decrease surface run-off volume in the built-up area. Method that used is spatial analysis. The formula calculates the volume of rain: Ih=LxK, and to measures the volume of rainfall: V=RxA. The built-up area changes from 458,507,000m2 to 535,155,000m2. The results depict built-up area change from 458,507,000m2 to 535,155,000m2. The built-up area expansion affected the increase in surface run-off from the average volume of 34,250,473m3 to 39,079,976m3. The way to decrease the volume of flooding which continously increased is by absorbing the volume of rainfall in each built-up area of every 100m2. The highest rainfall volume in December has been up to 1,100m3 in order that each built-up area of 100m2 have to absorb rainfall of 1,100m3 in the infiltration wells. Because the built-up area is different, it is calculated from the thickness of the rainfall multiplied by large, then the volume of rainfall must be absorbed. By storing and absorbing the rainfall in each built-up area, the surface run-off could be avoided in the area of Bandung basin.