예보강우의 시간분포에 따른 청미천 유역의 홍수 확률 평가

Abstract

The objective of this study was to assess the flood probability based on temporal distribution of forecasted-rainfall in Cheongmicheon watershed. Inthis study, 6-hr rainfalls were disaggregated into hourly rainfall using the Multiplicative Random Cascade (MRC) model, which is a stochastic rainfalltime disaggregation model and it was repeated 100 times to make 100 rainfalls for each storm event. The watershed runoff was estimated using theClark unit hydrograph method with disaggregated rainfall and watershed characteristics. Using the peak discharges of the simulated hydrographs, theprobability distribution was determined and parameters were estimated. Using the parameters, the probability density function is shown and the floodprobability is calculated by comparing with the design flood of Cheongmicheon watershed. The flood probability results differed for various values ofrainfall and rainfall duration. In addition, the flood probability calculated in this study was compared with the actual flood damage in Cheongmicheonwatershed (R2 = 0.7). Further, this study results could be used for flood forecasting.