Resumen
The changes of land surface imperviousness due to rapid development had contributed to the occurrence of flash floods. The runoff coefficient, C that represents the rainfall-runoff relationship in the catchment is one of important parameter being considered in estimating the peak discharge due to a rainfall event. This study aimed to investigate the influence of rainfall characteristics and land surface imperviousness on rainfall-runoff relationship. A series of laboratory experiments were conducted in a 2m x 1m sand flume to simulate the hydrological cycle in a laboratory scale catchment by varying the rainfall characteristics under different land cover conditions. The spatial distribution of rainfall was found to influence the flood peak and runoff volume in this study. The results revealed that the runoff coefficient was higher under non-uniformly distributed rainfall event. This study indicated that both spatial and temporal variations of rainfall should be considered to improve the accuracy in estimating the flood peak.