Author(s): Salwa Ramly, Wardah Tahir, Asmadi Ahmad, Noor Hisham Mohd Ghazali
Linked Author(s): Salwa Ramly
Keywords: Rainfall-runoff Model, Quantitative Precipitation Estimation (QPE), weather radar, HEC-HMS, streamflow
Abstract: Rainfall-runoff model is a model to simulate the hydrologic processes of the watershed system. Streamflow, which is the result from the rainfall-runoff model, is essential for flood analysis especially for high risk flooded area such as Upper Klang Ampang River basin due to rapid development. One of the main input components in the rainfall-runoff model is a precipitation data. Radar-based Quantitative Precipitation Estimation (QPE) is a method to estimate the distribution of precipitation amount or rainfall by using weather radar data. Gauge rainfall data is commonly used in the rainfall-runoff model as a precipitation input. Gauge rainfall data provide accurate rainfall data yet it has less spatial distribution. However, Radar-based QPE offer high temporal and spatial distribution of rainfall data yet limited accuracy of the rainfall data compare to gauge rainfall data. The objective of the analysis is to analyze the streamflow result from the HEC-HMS rainfall runoff model using gauge rainfall and radar-based QPE rainfall data. In the HEC-HMS model, SCS CN method was applied as loss model and SCS CN Unit Hydrograph as transform method. Two significant events were selected to analyze the streamflow results using two different precipitation input, radar-based QPE and gauge rainfall data. Calibration factor for radar-based QPE will be discussed to improve the quality of the accuracy for radar-based QPE. From the analysis, radar-based QPE showed positive results and is applicable to be use in the flood analysis at Upper Klang Ampang River Basin
Year: 2017