강우-유출수 기반 대체농업용수 확보를 통한 시범지역 이수개선 효과 분석

Abstract

This study quantitatively evaluates the effectiveness of a temporary storage-based alternative agricultural water supply system utilizing rainfall-runoff in improving water use security in a water-stressed upland farming area in Hapcheon-gun, Republic of Korea. A water security assessment model was developed to reflect actual field conditions, system configurations, and crop cultivation characteristics, simulating daily soil moisture, water demand, irrigation volume, and deficit. Four water security indicators—Water Utilization Safety (WUS), Water Supply Reliability (WSR), Water Supply Sustainability (WSS), and Water Supply Adequacy (WSA)—were applied to assess changes before and after system implementation. Results showed that the system increased average soil moisture by 7–11% and reduced the number of days below the growth inhibition point by 10–14 days. Irrigation deficits decreased by 16–18 m³/year, and the system secured an additional 486.1 m³/year of water on average. Correlation and regression analyses revealed that variables such as rainfall frequency and storage tank saturation days had more influence on additional water supply than total rainfall amount, indicating that rainfall pattern, rather than volume, critically affects water availability. The study highlights the necessity of considering rainfall frequency, intensity, and storage efficiency in system design. These findings provide a scientific basis for tailoring system configurations to regional climatic and hydrological conditions and offer policy insights for expanding the application of alternative water systems in upland agriculture.