龙门山北段平通河流域地貌演化过程

龙门山位于青藏高原东缘,是青藏高原周缘山脉中陡度变化最大的山脉,也是全球气候和构造活动最为强烈的地区之一,因此成为研究构造、气候如何影响山脉地貌演化过程这一科学问题的良好素材。在位于龙门山北段的平通河流域,汶川地震导致该区强烈的隆升、剥蚀作用,对研究该区地貌演化过程具有重要的启示意义。通过对平通河流域基于DEM数据的地形坡度、水系分布、河流发育程度等的分析,并综合研究区构造特征和岩性特征,获得该流域不同区域的地貌演化方向,其中两个区域的地貌演化最为剧烈:1.平通河流域位于北川-映秀断裂和彭灌断裂之间的地区,未来将发生较快的隆升,地貌向高、陡的方向演化,河流下切作用使河谷两岸形成更加陡峭的地形;2.在北川-映秀断裂上盘附近地区,在构造和气候作用下侵蚀、搬运作用强烈,山体将被快速剥蚀削低,但在河谷两岸也会形成更加陡峭的地形。

Geomorphic Evolution Process of Pingtong River Watershed in the North Longmenshan,China

The Longmenshan is located in the eastern edge of Qinghai-Tibet Plateau,it’s gradient change is greatest in the mountains in periphery of Qinghai-Tibet Plateau,it’s climate and tectonics is one of the most intensive areas in the world,so the Longmenshan is a good stuff to study the scientific problems.In the Pingtong river watershed,Wenchuan earthquake load to the stronger uplift and denudation,which is a important enlightenment to the geomorphic evolution of the area.Based on the structural feature,the lithologic feature,the analysis on the topographic slope,stream distribution and the growth degree of river in the Pingtong river watershed with DEM date.we could get the geomorphic evolution direction in the different area of Pingtong river watershed.The geomorphic two areas have the strongest change:1.the area between Beichuan-Yingxiu fault and Pengguan fault in the Pingtong river watershed will rapid uplift,whose geomorphic will become higher and steeper,the valley will become steeper with downcutting of the Pingtong river;2.at the condition of tectonics and climate,the denudation and transportation will get stronger in the other area,which near Beichuan-Yingxiu fault and at the up wall of fault.The mountains will be rapidly denudated and become lower,but the valley will also become steeper.