Using fractals to downscaling of rainfall forecast in Climate change

• Main Authors: Ping-Hui Yu, 喻秉輝
• Other Authors: Chang-Shian Chen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/48248117311070090794

碩士 === 逢甲大學 === 水利工程與資源保育研究所 === 98 === Under climate change impacting, the trait of rainfall is change everywhere in the world. Taiwan is a scarcity of water resources and rainfall is concentrated.The data from General Circulation Model (GCM) need downscaling then to apply in the watersheds of Taiwan. This study found the fractal dimensions exist in the monthly rainfall data of wet and dry season in Taiwan. First of all, the historical rainfall of dry and wet season were isolated, and rainfall to become rainfall dimensionless percentage. And through iteration function systems to establish the database of rainfall patterns, using the ratio of the total rainfall, select the corresponding form of rain has to time rainfall downscaling, and estimate the extreme rainfall. The results suggest that for the next rainfall event, by the atmospheric circulation model estimates of rainfall on the impact of extreme rainfall estimation part, the estimate of the dry season there were underestimated by percentage of the extreme error of about 30%; wet quarter of the estimated percentage of extreme values of the error within 20%.