應用趨勢分析探討氣候變遷下太麻里溪流域的水文變化

Due to the climate change and the extreme weather events, the precipitation in Taiwan has changed very dramatically. The hydrological conditions in a basin are highly related to the weather. In order to identify the effect of the climate change, we assess annual, seasonal and monthly trends of precipitation from 1981 to 2012, stream runoff from Augustin 1983 to July in 2009, and sediment load from 1984 to 2008 in the Taimali stream basin using the Mann-Kendall trend test and the Theil-Sen slope test. The results show that the precipitations of annual, wet period, autumn season, and in August have significant increasing trends. The τ values are 0.29, 0.27, 0.25, and 0.23, respectively. The stream runoffs of annual and autumn season also have significant increasing trends. The τ values are 0.27 and 0.24, respectively. In addition, the sediment loads of annual, wet period, and autumn season also have significant increasing trends. The τ values are 0.27, 0.25, and 0.25, respectively. Through the trend analysis, we can identify that the hydrological conditions in the Taimali stream basin are strongly affected by the climate change. It causes the annual precipitation, stream runoff, and sediment load significantly increasing, especially for the autumn season and wet period with obvious increasing trend.