Study on Integrated Climate Change Impact Assessment System for Regional Water Resources

• Main Authors: Tzu-Ming Liu, 劉子明
• Other Authors: 童慶斌
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/40199438046168157375

博士 === 臺灣大學 === 生物環境系統工程學研究所 === 98 === In recent years, the threat and increasing frequency of extreme weather rised up human attention on climate change, and advanced the study on climate change impact. The research method is developed, but yet needs an integrated assessment system. This study established an integrated climate change impact assessment system on reginoal water resources. The study area of this study is the Gaoping river basin which is located in south area in Taiwan. The carrying capacity of the water supply system restricted by shortage tolerance was analyzed and approached. The process and simulation tools on analyzing carrying capacity of water supply system were built. The approach of downscaling with climate region classification was established to estimate the effect of climate change. The risk of water shortage was also adopted for climatic change conditions. The integrated assessment system includes downscaling with climate region classification, weather generator, GWLF model, water resources system dynamics model and Analytic Hierarchy Process(AHP) tool, and was built with Visual Basic computer program. It provides the tools in the process of climate change impact assessment, and could be applied for the related research on climate change. The downscaling with climate region classification used principal component analysis with cluster analysis to classify Taiwan into 9 climate regions. The changing value of each general circulation model in the nearest point to each climate region was adopted and corrected bias to evaluate future precipitation and temperature reasonably. Using weather generator to generate daily precipitation and temperature data for hydrological model simulation, the inflow was simulated by GWLF model and put in water resources system dynamics model to estimate the carrying capacity of water supply system in water resources. Then the AHP tool can help to find the prior plan for the decision maker. This study used System Dynamics software- VENSIM to build the water resources system dynamics model of Goaping and Zenwun river basin with considering the water resources structures and water demands, and evaluate the carrying capacity of water supply system in Gaoping river basin. The carrying capacity of water supply system is the most available water supply under the tolerance of water shortage. The Deficit Percent Day Index (DPD Index) was used and the tolerance of water shortage,DPD=1500%-day, was adopted to analyze the carrying capacity of water supply system and related water shortage index of Gaoping river basin in this study. The carrying capacity of water supply system was adopted for different return period of DPD. The carrying capacity is 1.78 million CMD referring to return period of 2 years of water shortage risk which was defined as the probability of water shortage over the tolerance, DPD=1500%-day. The carrying capacity also adopted for different SI. It is 1.43 million CMD, 1.91 million CMD, and 2.32 million CMD for SI=0.1, SI=0.5 and SI=1, respectively. The SI is 0.39 for present which the domestic and industrial water demand is 1.8 million CMD, and the SI will rise up to 1.03 in year 2031 due to expanded water demand. The risk of water shortage will rise up from 52% to 74.1%. The water supply system in Gaoping river basin is under two threats in the future. One is the expanded water demand, and another is climatic change. Using integrated assessment system to simulate, most results indicated that under threast of climate change and expanding water demand, the carrying capacity will decrease down and the water shortage will rise up. To the capacity of water supply system for the future, the consideration is not only growing water demand but also the impact of climate change.