Conversion Factors for Ten-Day Irrigation Duties of Paddy Rice in the Han River Basin

한강수계 논의 순별 단위용수량 변환계수

Seasonal water requirements by paddy rice is important to water budgeting for the water resources planning at a basin scale. This paper compares the water requirements resulting from different approaches for the Han River Basin. The demands from the drought years of 1967 and 1968 were found to be significantly less than the irrigation standards. This may result in significant underestimation of the basin-wide water demands. A conversion factor method is proposed to define seasonal irrigation demands. The factor is defined from the ratios of the standards for each growing stage to the drought year demands. The results were compared satisfactorily with those from the irrigation standards, and readily applicable to the water resources planning.