The effect of climate change on the land hydrologic cycles in Taiwan

• Main Authors: Waiting Tien, 田維婷
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/84456529267202258096

碩士 === 國立中央大學 === 水文所 === 91 === Due to greenhouse effect, the gradual increase of temperature has been found to be an important factor changing the global climate. The possible outcomes of climate change will be the increase of precipitation, surface runoff, and evapotranspiration, the decrease of soil moisture, and the high frequency of extreme weather events, such as floods and droughts. However, the results at a global scale may not reflect the outcome in regional scale, or in an even smaller scale like the island of Taiwan. Therefore, it is worthwhile studying the effect of climate change on the hydrologic cycle in Taiwan. In order to effectively estimate the impact of climate change on land hydrology in Taiwan, a simple water balance model is developed to account for precipitation, evapotranspiration, surface runoff, and groundwater infiltration of the land hydrologic cycle. Under different climate change scenarios, it is applied to access the impacts of climate change on these land hydrologic processes. Daily temperature and precipitation are major input data required for this study, while landuse conditions is used to account for land surface roughness. A total of nine climate change scenarios is applied to project possible climate variations in the future. Under current climate condition, the mean annual precipitation is around 928 billion tons, evapotranspiration is 314 billion tons, surface runoff is 414 billion tons, and groundwater infiltration is 200 billion tons in Taiwan. The simulation results indicate that: Although predictions by different GCMs or region climate model are different, the trend of more extreme precipitation and surface runoff can be seen in most cases. Since groundwater infiltration is closely related to evapotranspiration, surface runoff, and rainfall, the amount of groundwater infiltration in Taiwan has a great possibility to gradually decrease under the impact of climate change.