Uncertainty of sediment load prediction at a detention pond based on monte carlo simulation

Abstract

Sediment accumulation in detention ponds has adverse effects on the intended uses of the pond. Higher volume and depth of sediment can cause flooding when storm events occur and can cause the operational failure of pond. Monte Carlo simulation is used to predict sediment loads and depth of accumulation at the Ledang Heights pond in Nusajaya, Johor. The simulation results show the maximum occurrence for observed sediment loads was 0.0062 tons (16.51%). While the maximum occurrence of sediment depth was 0.0005 mm (17.53%). Prediction analysis for 100 years by the MUSLE and trap efficiency methods showed linear increments of sediment loads and depth with time. Monte Carlo simulation gave the maximum probability of occurrence for predicted sediment loads and depth. By elucidating risk associated with the sediment load and depth, rational decision making for the most practical operation of detention pond can be achieved.