Abstract:
Floods have accompanied mankind throughout its entire history. Although the causes for this have varied, e.g. extreme changes in the river catchments and material deposition along the riverbed, the impact is the same. Floods are dangerous to people’s lives and vital interests. Floods are now the main hydrological topics worldwide. The sensitivity of environment and national economy to the impact of floods is becoming ever more pronounced. In certain developing countries such as Indonesia, the land use in the catchment area changes continuously and it is very difficult to be restrained. No wonder that flood damage in the past that was caused by discharges having a return period of 100 years, can today be the results of a 20-year maximum discharge.