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2026 Vol.27, Issue 10 Preview Page
Diagnosis of Water Supply Safety in Agricultural Reservoirs Using the Water Availability Sufficiency Index (WASI)

농업용수 가용성 충족지수(WASI)를 이용한 농업용 저수지의 용수공급 안전도 진단

Taehwa Lee1
,
Yongchul Shin2*
,
Younghun Jung3
,
Beomgu Kim4
이 태화1
,
신 용철2*
,
정 영훈3
,
김 범구4
1Postdoctoral Researcher, Center for Smart Agriculture Innovation, Kyungpook National University
2Professor, Department of Agricultural Civil Engineering, Kyungpook National University
3Professor, Department of Advanced Science and Technology Convergence, Kyungpook National University
4Ph.D. Student, Department of Advanced Science and Technology Convergence, Kyungpook National University
*Corresponding Author
1 October 2026. pp. 61-72
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Abstract

The Water Availability Sufficiency Index (WASI) was presented to quantitatively diagnose the water supply safety of agricultural reservoirs. WASI is a dimensionless index defined as the available storage at the start of irrigation plus the usable inflow during the irrigation period, divided by the total water requirement for the same period. WASI was estimated for 48 reservoir-year cases of 16 agricultural reservoirs in the four major river basins of South Korea from 2021 to 2023, using the water balance results of the KRC-Hydraulic & Hydrology Analysis System (K-HAS). The median WASI was 2.158, ranging from 0.897 to 4.443. Although the storage rate at the start of irrigation exceeded 90 % in 43 of the 48 cases, WASI ranged from 1.067 to 4.443 within that narrow band, indicating that the storage rate alone cannot assess water supply safety. The ratio of spill to total inflow increased from 61.5 % in 2021 to 80.2 % in 2023, showing that the usable inflow should be distinguished. Water shortage occurred in five cases. Where WASI was below 1.0, additional water sources are required. Shortage also occurred where WASI exceeded 1.0, because the storage had been drawn down to the dead storage before the later inflow arrived.

Keywords
Agricultural reservoir
Water availability sufficiency index
Water supply safety
Reservoir water balance
Total water requirement

농업용 저수지의 용수공급 안전도를 정량적으로 진단하기 위하여 본 연구에서는 농업용수 가용성 충족지수(Water Availability Sufficiency Index, WASI)를 제시하였다. WASI는 관개 시작 시점의 가용저수량과 관개기간의 이용가능 유입량을 합한 총가용수량을 같은 기간의 총용수량으로 나눈 무차원 지수이다. 국내 4대 권역에 위치한 16개 농업용 저수지를 대상으로 2021년부터 2023년까지 수리수문설계시스템(K-HAS)의 물수지 분석 결과를 이용하여 48개 저수지·연도 조합의 WASI를 산정하고, 같은 기간의 농업용수 부족 특성과 비교하였다. 산정 결과 WASI의 중앙값은 2.158, 범위는 0.897에서 4.443이었다. 관개 시작 시점의 저수율은 48개 사례 중 43개가 90 % 이상으로 분포의 폭이 좁았음에도 해당 구간에서 WASI는 1.067에서 4.443까지 나타나, 저수율만으로는 저수지의 공급 안전도를 판단하기 어려운 것으로 나타났다. 전체 유입량 중 무효방류량이 차지하는 비율은 2021년 61.5 %에서 2023년 80.2 %로 증가하여 이수 목적으로 활용 가능한 유입량의 구분이 필요하였다. 농업용수 부족은 5개 사례에서 발생하였으며, WASI가 1.0 미만인 사례는 확보된 수자원 자체가 총용수량에 미달하여 보조수원 확보가 필요한 상태였다. WASI가 1.0 이상인 사례에서도 부족이 발생하였는데, 이는 부족 개시 시점에 저수량이 사수용량까지 소진되어 관개기간 전체로는 수자원이 충분하였더라도 유입이 부족 발생 이후에 도래하였기 때문으로 나타났다.

키워드
농업용 저수지
농업용수 가용성 충족지수
용수공급 안전도
저수지 물수지
총용수량
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Information
  • Publisher :Korean Geo-Environmental Society
  • Publisher(Ko) :한국지반환경공학회
  • Journal Title :Journal of the Korean Geo-Environmental Society
  • Journal Title(Ko) :한국지반환경공학회 논문집
  • Volume : 27
  • No :10
  • Pages :61-72
  • Received Date : 2026-09-10
  • Revised Date : 2026-09-11
  • Accepted Date : 2026-09-23
  • DOI :https://doi.org/10.14481/jkges.2026.27.10.61
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