Sustainability assessment of estuarine reservoir under future environmental changes for water use and flood control

This study evaluates the sustainability of estuarine reservoir water resources for water use and flood control, considering future environmental changes such as climate and land use changes. Future environmental data were constructed, and a watershed-reservoir linkage model simulated reservoir water resource changes. A sustainability index based on reliability, resiliency, and vulnerability was used to assess the current management plan. The analysis showed that the current plan for Ganwol estuarine reservoir may cause future issues with water use and flood control, with sustainability indices ranging from 0.2 to 1 for water use and 0.65 to 1 for flood control. Water use sustainability was found to be lower than flood control sustainability, due to differences in design frequencies and the reservoir's artificial drainage capacity. An analysis of changes in sustainability from raising the control water level during the non-flood season showed a decrease in water use failures, with the sustainability index increasing by 0.2 to 0.75, improving sustainability. While effective for water use, the plan may reduce flood control sustainability, indicating the need for additional measures. This study provides a quantitative method to assess reservoir management sustainability under future environmental changes.