Flood control strategy in waibakul city,central sumba,Indonesia

摘要

Waibakul City,Central Sumba Regency,East Nusa Tenggara Province,Indonesia is affected by floods every year that comes from overflow of drainage channels.The area of Waibakul is 76,44 km~2 and dommated by agricultural land.The drainage system is incorporated into the irrigation system,thus forming a complex network of channels.The topography of the area is very flat,with slope(0 to 3)% reaching 78.56% and forming natural basins that are used as rainwater catchment reservoirs.The results of evaluation show that the majority of channel capacity is not roportional to the burden that must be discharged.The reservoir performance is not maximal because the water discharge system only relies on natural water absorption into the soil,so if there is a successive rain then the reservoir is full thus the reservoir control capacity becomes very small.The recommendation for flood control strategies are:(1).Divide the catchment area into sub-catchment areas based on the drainage service area,so the problems can be more easily solved and completed gradually.(2).Increase the capacity of multiple channels.(3).infiltration wells as a means of reservok water drainage.(4).Control the burden of flood discharge to the office area by making a shotcut.(5).Control the flood water level in rivers that is crossing central office area by making long storage with spillway.