Assessing water distribution and efficiency by coupled hydraulic-hydrological modeling for irrigation canal network

In South Korea, performance of irrigation systems can be improved through hardware changes, such as canal linings and the installation of control structures, as well as through operational improvements, such as proper and timely operation, and improved communication between water supply agencies and water users. Improving irrigation water delivery performance through canal networks is one of the most economically essential options in meeting growing water demands and sustaining the productivity of irrigated agriculture. In this study, for the purpose of evaluating the efficient use of water resources in agricultural productions and operations, we analyzed the distribution of amount of water for each irrigated area and irrigation efficiency using a hydraulic-hydrological model, EPA-SWMM (United States Environmental Protection Agency Storm Water Management Model). In addition, we assessed agricultural water supply and water supply vulnerability using irrigation efficiency indicators. As a result of the agricultural water distribution simulation, the canals located in the upstream showed a high irrigation efficiency of more than 60%, and the canals located in the downstream showed a low irrigation efficiency of less than 50%. Based on the results, the critical areas can be successfully identified where water is scarce in the irrigation area and monitoring the spatio-temporal agricultural water distribution can be more effectively realized.