Climate Change Assessment over Korea Using Stochastic Daily Weather Data

Cliamte change impacts on precipitaion, wet and dry days length, frost and hot day lengrh, radiation and spatial distribution of heavy rainfall have been studied for futur decads of 210s, 2020s and 2030s by purturbing the historical daily weather data by LARS-WGa stochastic weather generator over Korea This research has been done for assessing the impact of future climate on sustainable water resource and risk in hydrological application. Synthetic series of daily precipitation, radiation, minimum and maximum temperature of 10 selected synoptic stations of Korea in climatology period were produced. Statistical tests concluded that synthetic data were significantly identical to the observed values. Climate change impacts on precipitation, heavy rainfall, temperature, wet and dry day length as well as hot and frost day length over Korea have been studied using sequences of synthetic daily data that generated by perturbing historical data with climate scenarios that had been created from ECHOG data in different periods. Results showed that annual amount of rainfall, dry day length and wet day length will be increase by maximum 7%, 11% and 2% during 201Os, 2020s and 2030s, respectively. Meanwhile the amount of frost day will decreased by maximum 22% during same period, with the greatest in Cheju and the lowest in Daejeon. Hot day length will be increase by 19% as a mean. Mean decadal increase in temperature detected to be 0.9°C, 1.4°C and2.0°C in 2010s, 2020s and 2030s, respectively. Maximum and minimum changes in of radiation were detected in August and September with 4% and +6%. Absolute thresholds of major and extreme rainfalls have been increased significantly by 10%, 17% in future decades. In spite of increasing trend in mean amount of annual rainfall, an abrupt decrease is detected in 2010s.