연구보고서
- 저자
- 김대하 박사
- 작성일
- 2018.04.24
- 조회
- 441
- 요약
- 목차
Climate change driven by human-made impacts is expected to pose challenges in water resources management, necessitating robust adaptation strategies to sustain human societies and ecosystems. However, many studies have taken the “predict-then-act” paradigm to assess impacts of global warming on hydrologic and agricultural systems. Usually, climate change impact assessments are dependent on a handful of climate projections from the general circulation models (GCMs) in which significant uncertainty sources are involved. In practice, the deep uncertainty present in climate projections may hinder policy-makers to use the scenario-led adaptation strategies owing to high potential regrets. To consider the deep uncertainty in climatic projections, the “robust decision-making” paradigm was taken in this study to assess impacts of global warming on a large river system. A decision-centric approach was employed to assess water supply efficiency in the Geum River Basin, South Korea, in which climate change and conflicting demands are concerns of water managers. First, a climate-stress-inducing stochastic model and a water resources optimizing scheme were used to develop response surfaces of supply efficiency to climatic stressors. Then, climate change impacts were assessed by superimposing 49 GCM projections on the response surfaces under stabilized and increasing greenhouse emission scenarios. Results show that the Geum River Basin is unlikely to experience significant water scarcity for the upcoming 20 years of 2020-2039. The worst water scarcity expected, according to the 49 GCMs, was less than 2.5% of the total demand. The reliability to satisfy 95% of monthly demand for a bi-decadal period was 100% under optimal water resources management. To optimize water management under 20% reduction in bi-decadal mean annual precipitation, it was indicated that the smaller dam in the upper river should increase water release in order for the larger dam in the lower river to have better management flexibility. This study highlights that month-by-month optimal water management can be a robust strategy for adaptation to shifting climate. It also emphasizes that the robustness-based framework can visualize system responses to climatic stresses, and can provide reliable assessments by overlaying numerous climate projections.