기후변화에 의한 제주도 하천유출 및 가뭄 영향 분석

Abstract

With increasing the frequency of precipitation extremes due to climate changes, flood damages and drought damages are predicted to grow in Jeju island. To estimate the effect of stream discharges and droughts caused by climate change in jeju island, climate change impact assessment was conducted with a climate change scenario. the climate change scenario was constructed through quantile mappting. A discharge scenario was simulated by SWAT model and an integrated hydrological modeling. The quantile mapping of hybrid downscaling method, by effectively reducing errors of the local climate model, enabled to produce reliable regional precipitation scenarios for water resource impact assessment of Jeju island in the precipitation scenarios. the precipitation consistently increased in all of four regional meteorological. In seasonal precipitation analysis, fall and winter showed a large precipitation increase. the discharge scenarios were applied to Oaedo stream in northern jeju and Gangjeong stream in southern Jeju. The annual average discharge was found to decrease slightly in the north area of Jeju and increase for the south area of Jeju. However, the maximum discharge frequency increased for both sides. Especially, Summer/Fall discharge was estimated to have no benefit for the water resource security but to increase flood damages. A drought scenario was estimated using the standardized precipitation index SPI. SPI was applied to four regional meteorological in Jeju island. In predicted drought scenarios, SPI 12 relatively simple fluctuations compared to SPI 6 at observatories. The predicted drought scenario showed a large increase in fluctuations in all weather stations. Seasonally, it was predicted that severe drought (PSI -1.5 or below) would occur during spring and that drought damages would increase. As the results of the impact of climate changes on the water resources of Jeju island, it was found that the intensity and frequency of droughts and discharge would increase and enhance flood damages and drought damages. Therefore, as the results of climate changes, water resource security and be threatened and stream management can be challenging in Jeju island. Also, regional water resource response plans for climate changes need because the results varied by regions over time.