Assessment of Water Supply Stability for Drought-Vulnerable Boryeong Multipurpose Dam in South Korea Using Future Dry Climate Change Scenarios

Kim Kim,Lee Lee

doi:10.3390/w11112403

Abstract

This study assessed the water supply stability for Boryeong multipurpose dam by applying future dry climate change scenarios and Soil and Water Assessment Tool (SWAT). CMCC-CM, INM-CM4, and IPSL-CM5A-MR RCP 4.5 and 8.5 scenarios were selected as the future dry conditions using Runs theory and Standardized Precipitation Index (SPI). For historical (1980–1999), present (2000–2019), and future periods (2030s, 2050s, 2070s, and 2090s) of the 6 scenarios, SWAT model was used to simulate the future dam water supply stability. The stability was evaluated in terms of reliability (RT), resilience (RS), and vulnerability (V) based on the monthly target storage. The results showed that the future RT can be decreased to 0.803 in 2050s IPSL-CM5A-MR RCP 8.5 scenario from present 0.955. The future RS and V showed the minimum value of 0.003 and the biggest value of 3567.6 × 106 m3 in 2070s IPSL-CM5A-MR RCP 4.5 scenario. The future RT, RS, and V showed that the dam has low resilience and is vulnerable to future drought scenarios.

Highlights

Climate change is a major factor affecting watershed hydrological cycle that causes natural disasters such as flood and drought resulting in large-scale damage of human life and economic loss [1]
By the continuing rainfall deficit, the dam storage rate reached 7.5%, the lowest value since the dam operation in 1998. This long period of drought caused the first restriction of municipal water supply from multipurpose dam operated by central government in South Korea
Since the Boryeong Dam was designed to endure drought for 20-year return period, the evaluation periods were divided into 20-year interval from historical period (1980–1999), present period (2000–2019), and future periods (2030s: 2020–2039, 2050s: 2040–2059, 2070s: 2060–2079, and 2090s: 2080–2099)

Summary

Introduction

Climate change is a major factor affecting watershed hydrological cycle that causes natural disasters such as flood and drought resulting in large-scale damage of human life and economic loss [1]. The exacerbation of seasonal rainfall in a changing climate may have profound effects on water resource systems and many attempts have been exercised to quantify drought. Panel on Climate Change (IPCC) fifth assessment report [2] predicted that global average temperature would increase by 4.8 ◦ C in 2100 in the case of business as usual greenhouse gas emissions. In South Korea, the average temperature is expected to increase up to 6 ◦ C in 2100 compared to the present status. The changes will bring out significant influences on hydrologic behavior and it is necessary to predict and evaluate the effects of seasonal big variation on hydrologic environment and the water resources management [3,4,5].

Methods

Results

Conclusion