本研究將針對石門水庫集水區，運用土地利用現況資料與SRES氣候預設情境，探討未來氣候變遷與土地利用改變對GWLF模式模擬流量與泥砂產量之影響。 研究內容包含土地利用改變與氣候變遷兩個部份，首先土地利用改變方面，利用GWLF模式（Generalized Watershed Loading Function）配合兩個不同年份之土地利用現況資料與未來預設情境氣象資料模擬未來之流量變化，並進一步加入人為的方式變更其地表覆蓋物。氣候變遷方面，使用歷史氣象資料，與SRES (Special Report on Emissions Scenarios)預設情境氣象資料輸入GWLF模式所模擬出未來短、中、長期之流量與泥砂產量，評估氣候變遷對其可能造成之影響與衝擊。 分析結果顯示，流量會受到土地利用型態的改變而有所影響，且未來的降雨量、流量及泥砂產量在氣候變遷影響下呈現下降的趨勢，在枯水期相對於現況為減少趨勢且顯著於豐水期，未來降雨量多集中在豐水期顯示降雨分布不均的情況更為嚴重，顯示未來流量減少則可供水量勢必降低，未來易發生嚴重乾旱。 This study employed present land-use data and SRES climate scenarios to simulate the influence of stream flow and sediment under the future condition of climate change and land-use change by GWLF model in Shihmen Reservoir watershed. The content of research includes two parts: land-use change and climate change. First, several different land-use sets were applied to the GWLF model to simulate the change of steam flow. Secondly, to estimate the impact of climate change, historical meteoric data and SRES climate scenarios was used to simulate the future short-term, med-term and long-term change of stream flow and sediment. The result shows the stream flow changed by different land-use. Under the impact of climate change, the rainfall, stream flow and sediment all decrease in the future. The decrease pattern in dry season is more conspicuous then that in the wet season. The rainfall will concentrate in the wet season and the spatial distribution will be more serious unevenness in the future. Therefore, if the stream flow decreases, the supply will decrease, too. The serious drought will happen more frequent in the future.
