Drought is a recurrent disaster that may exert catastrophic influences on ecosystems, wildlife, and human societies. It is commonly defined as abnormally prolonged deficiency in precipitation that causes a significant hydrological imbalance. However, this conventional precipitation-based definition only considers dry conditions indicated by the lack of water supply, irrespective of water demand. Although the general drought classification includes the socioeconomic drought, which is defined by comparing water supply and demand, the literature that considers water users’ demand in drought assessment is limited. This study addresses this concern with three important issues on drought and climate change in South Korea: (1) future direction of drought risk in climatic observations (i.e., supply-side drought risk) in terms of trends, severity, and spatial extent; (2) differences between a socioeconomic drought in a regulated agricultural watershed and conventional supply-side drought; and (3) impacts of global warming on frequency and magnitude of water scarcity that can trigger extreme socioeconomic droughts in the agricultural watershed. In addressing these issues, high-resolution grid precipitation and temperature data were used to calculate drought indices, to simulate natural inflows in the reservoir, and to estimate the water demand for rice-planting areas supplied by the reservoir. Using the inflow and agricultural demand estimates with a theoretical reservoir operation policy, changes in frequency and severity of water scarcity were assessed in the context of climate change. Results show that trends in the conventional drought indices are unlikely to indicate increasing drought risk, while severity and spatial extent of severe drought areas tend to be intensified and growing. The conventional drought indices and the socioeconomic drought had similar temporal variation when human impacts did not exist. However, they are significantly different when the reservoir operation alters natural flow regime. Additionally, the climate change impact assessment on water scarcity indicated that the regulated river system is more sensitive to changes in long-term averages of precipitation and temperatures than the natural system, despite less climatic risks in the regulated system. The high sensitivity of the regulated system can be increased by augmented reservoir capacity, such that adaptiveness of the system to climate change is expected to rapidly decrease. On the other hand, a non-structural adaptation measure that converts the planting strategy from transplanting to direct sowing, had less sensitivity to climate change than the increasing reservoir capacity.

1. 서론

1.1 연구배경

1.2 연구목적 및 범위

1.2.1 연구목적

1.2.2 연구의 범위

2. 자료 및 연구방법

2.1 기상자료 및 연구대상지역

2.2 기상관측기반 가뭄평가

2.2.1 가뭄지수

2.2.2 융설 현상(Snowmelt Process)의 고려

2.2.3 가뭄지수의 시･공간적 변동성 분석

2.3 물수요-공급기반 농업가뭄평가

2.3.1 물부족 및 사회경제학적 가뭄지수

2.3.2 유출 및 저수지운영 모의

2.3.3 물수요량 산정

2.4 저수지 시스템의 물 부족량에 대한 기후변화 영향평가

2.4.1 상향식(Bottom-up) 기후변화 영향평가

2.4.2 관측기상특성의 추계학적 모의

2.4.3 GCM 공간상세화

3. 결과 및 고찰

3.1 기상관측 기반 가뭄평가

3.1.1 추세분석을 통한 가뭄 위험도 평가

3.1.2 공간분포 및 가뭄심도 분석을 통한 가뭄위험도 평가

3.1.3 요약 및 미래 가뭄위험도 평가

3.2 지소저수지 유역 가뭄평가

3.2.1 기상자료 기반 가뭄평가

3.2.2 수요-공급량 기반 가뭄평가

3.2.3 수요-공급량 기반 가뭄평가 요약

3.3 저수지 운영에 지구온난화가 미치는 영향 분석

3.3.1 물 부족과 가뭄의 비교

3.3.2 물 부족 빈도 및 심도의 기후변화에 대한 민감도 분석

3.3.3 CRF를 이용한 지소저수지 물 부족의 기후변화 영향평가

4. 요약 및 결론

4.1 기상관측 기반 가뭄평가

4.2 수요-공급량 기반 가뭄 평가 및 기후변화 영향평가

4.3 연구의 활용성

4.4 결론 및 제언

REFERENCE