以SGI指数法评价高屏溪流域之干旱特性-中华水土保持学会.PDF

2015 年中華水土保持學會年會及學術研討會 以SGI 指數法評估高屏溪流域之乾旱特性 [1]* [2] [3] 張家富 葉信富 李振誥 摘 要 近年來受到極端氣候的影響，臺灣面臨嚴重的缺水危機，且因降雨型態的改變，使得乾旱現象 愈趨明顯，間接影響地下水的補注。因此 ，本研究以高屏溪流域作為研究區域，選定7個地下水位站及鄰近 7個雨量站之長時間監測資料，利用標準化地下水指數評估法(Standardised Groundwater Index, SGI)與標準化 雨量指數評估法(Standardised Precipitation Index, SPI)分析該區域乾旱特性。本研究分析高屏溪流域1997年 至2014年地下水位與雨量資料，結果顯示，2003年至2005年為高屏溪流域之連續乾旱年。另外，透過計算 SGI和SPI兩者間的交互相關函數分析其最大交互相關函數(qmax) ，結果顯示qmax與乾旱事件持續的時間為正 相關，並得知qmax越大發生乾旱事件持續的時間越長，反之當qmax越小則持續時間越短。本研究結果可提供 高屏溪流域水資源管理參考。 關鍵詞 : 地下水位、SGI 、SPI 、交互相關函數 Standardised Groundwater Index for Drought Characteristics in Gaoping river basin, Taiwan Chia-Fu Chang [1]* Hsin-Fu Yeh[2] Cheng-Haw Lee[3] ABSTRACT Recent years, because of the extreme climate, Taiwan is facing water scarcity problem seriously. The changes of rainfall patterns that makes phenomenon of drought significantly, and indirectly affects groundwater recharge. The Gaoping river basin in southern Taiwan is examined in this study to assess its drought characteristics. Choosing 6 groundwater level stations and rainfull gauges nearby each station. Using the Standardised Groundwater Index (SGI) and the Standardised Precipitation Index (SPI), comparing with each other to analyze drought property in the area. The results indicate that 2003 to 2005 are drought events in this study area. There is a positive linear correlation between groundwater drought duration and cross-correlations (qmax). The maximum length of groundwater droughts defined by SGI is an increasing function of qmax, meaning that relatively long-term groundwater droughts has a relatively long-term crosscorrelations between SGI and SPI. The consequence can provide valuable information for hydrologica