평야부 용수계통을 고려한 농업용 저수지 이수안전도 평가 = Assessing Water Supply Reliability of Agricultural Reservoirs with Irrigation Canal Network Consideration

다국어 초록 (Multilingual Abstract)

Agricultural reservoirs supply water to approximately 63.7% of irrigated paddy fields, making stable supply essential for maintaining crop productivity.
Water supply reliability is a key indicator of water resource stability; however, in the absence of standardized evaluation criteria, drought frequencyhas traditionally been used as a proxy to assess reservoir performance. Most reservoirs were constructed between the 1940s and 1970s, necessitatinga reassessment of their current reliability under evolving management practices and changing water demand. This study quantified water supplyreliability using two metrics: the Water Utilization Safety Rate (WUSR) and the Water Supply Reliability Rate (WSRR), incorporating the structure anddynamics of rural irrigation systems. Water demand and shortages were estimated by comparing management-level ponding depths across irrigated areasusing the EPA Storm Water Management Model (EPA-SWMM), which simulates hydraulic delivery through canal networks. Results were validatedagainst the K-HAS model, a c onventional w ater b alance method w idely used i n Korea. W hile K -HAS i ndicated c onsistently high r eliability, theSWMM-based analysis revealed equal or lower grades, reflecting reduced actual supply reliability. Yongseong Reservoir showed the lowest WUSR,mainly due to overestimated demand influenced by field conditions and SWMM's limitations. In general, SWMM projected higher water demand thanK-HAS, resulting in noticeable discrepancies. This study emphasizes the importance of accounting for irrigation network complexity in reservoirreliability assessments. Improving SWMM modeling accuracy and establishing standardized evaluation criteria will enhance future assessments andsupport more effective agricultural water resource management.