A Study on Areal Rainfall in the Han River Basin Based on Radar Data

Abstract

Areal rainfall is an essential factor used in the basin-scale hydrological analyses, and accurate areal rainfall is required to ensure the reliability of the associated hydrologic output. Areal rainfall is the average of the rainfall that occurs in a watershed. Areal rainfall calculation methods based on point observation networks are based on the assumption that point rainfall is representative of the entire basin. Radar can provide spatially continuous rainfall data to obtain realistic areal rainfall. In this study, radar rainfall data was used to evaluate the relationship between conventional and actual areal rainfall. Consequently, a significant difference was noted between the conventional area rainfall and the actual area rainfall because the conventional area rainfall did not reflect the distribution characteristics of rainfall in the basin and the variability of quantitative characteristics. Therefore, radar rainfall that can reflect the distribution of rainfall in the basin must be considered when analyzing the hydrological volume at the basin level, and an appropriate correction plan must be prepared based on the results of this study when using the conventional area rainfall.