以測高曲線探討台灣主要河川集水區演育情況

Abstract

台灣位於板塊碰撞帶上，屬於構造活動發達的地區。測高曲線積分為一測計指標，可顯示集水區受到抬升與侵蝕過程中的地形演育情況。測高曲線由集水區內各個高度和對應面積所構成，測高曲線積分值為曲線下的面積，表示集水區內演育的過程中地表所剩餘殘土比例。 本研究使用SRTM DEM與台灣地區40公尺數值地形模型為研究資料，以台灣二十六個中央管轄河流之集水區為研究區域，計算出各流域集水區之測高曲線以及測高曲線參數，分析集水區地形演育情況，成果顯示東部與中部的集水區構造活動較明顯。將集水區測高曲線積分值對集水區地形測計參數與幾何型態因子進行相關性分析，地形測計參數與測高曲線積分有正相關，幾何型態因子與測高曲線積分無相關性。由於二十六個流域所計算出之測高曲線積分值偏低，因此嘗試以子集水區計算測高曲線積分，分別以SRTM與台灣地區40公尺數值地形模型在二十六個流域萃取出子集水區計算測高曲線，利用測高曲線參數分析流域內的演育情形。

Taiwan is located at the plate collision zone is the area of developedtectonic activity. Hypsometric integral is a morphometric parameter representsthe evolution situation of the catchments by uplift and erosin process. Hypsometric curve composed of the differentheightsand the corresponding areas in the catchment.Integral value is the area under the curve, indicates the remaining soil ratio of the basinin the process of evolution. SRTM DEM and Taiwan40m DEM is used in this study.Twenty-six central jurisdiction of river basins for the study area. Calculatinghypsometric curve andparameters.Analysis oftopography evolution for basins.The results show that tectonic activity of the catchments in eastern and central Taiwan is more significant.Correlation analysispresents gmorphometric parameters positively correlated with the hypsometric integral, and there is no correlation between basin form factors with hypsometric integral. Due to hypsometric integrals of twenty-sixstream basins areon the low side. This study attempts to calculate hypsometricintegrals of sub-basins. Use SRTM DEM and Taiwan40m DEM tocalculate hypsometric curve of sub-basins extracted from twenty-sixstream basinsrespectively. Discussion of the evolutionwithin the stream basin.