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目前,利用DEM衍生的地貌参数对大面积区域构造活动进行量化分析的研究相对较少。本文以岷江上游流域为例,利用ASTER GDEM数据和GIS技术,提取了该流域面积高程积分值(HI)、河长坡降指数(SL)、流域盆地不对称度(AF)、盆地形状指数(BS)、谷底宽度与谷肩高度比(VF)和水系分维数(FD)6种地貌参数,对其进行了等级划分,并量化了研究区相对构造活动强度(IAT)。结果显示:岷江上游流域有较高的SL、AF、BS值,较低的VF及FD值,中等HI值,其IAT值为1.33,分类等级为1级,表明该流域侵蚀程度强烈,流域形态狭长,河谷呈V型形态,受构造活动影响显著,地貌发育处于幼年期晚期,中年期早期。研究结果与区域地质背景较为吻合,该方法可为进一步探讨区域构造活动差异性提供新的手段。
At present, there are relatively few studies on the quantitative analysis of tectonic activity in large area using the geomorphic parameters derived from DEM. Taking the upper reaches of Minjiang River as an example, the ASTER GDEM data and GIS techniques were used to extract the data of HI, SL, SL, AF (basin shape index BS), valley width to valley height ratio (VF), and water system fractal dimension (FD), were classified and their relative tectonic activity intensity (IAT) was quantified. The results showed that the upper reaches of Minjiang River had higher values of SL, AF, BS, lower VF and FD, medium HI, IAT 1.33, and classification level 1, which indicated that the watershed had a high degree of erosion and the watershed morphology Narrow, valleys were V-shaped, significantly affected by tectonic activity, landscape development in late juvenile, early middle age. The results are in good agreement with the regional geological background. This method can provide new means for further exploring the differences of regional tectonic activities.