中文摘要：

河流地貌对新构造活动具有非常敏感的响应，水系形态能够较好地记录构造活动方式，水系形态分析可以为研究新构造的演化过程提供有力的证据。位于青藏高原东缘的龙门山与四川盆地是青藏高原周边最陡的地形梯度带，沿高原东缘发育青衣江、岷江、涪江和嘉陵江等一系列斜交于龙门山断裂带的水系。利用卫星遥感图像和数字高程模型（DEM）数据提取构造地貌和水系特征，对龙门山构造带水系形态进行分析研究，发现龙门山南西段冲断带褶皱具有横向生长的演化特征，逆冲褶皱带的构造演化影响青衣江和岷江水系的演化和重组，同时也控制着研究区晚新生代的沉积格局。受断裂带右旋走滑作用的影响，龙门山北东段水系表现出系统右旋错位特征，在北川县擂鼓镇至曲山镇一带涪江水系上游的重要支流一湔江出现3．8km的右旋错位，并导致湔江北川段出现河流袭夺和水系重组现象。根据涪江上游发生的5km和4km最大右旋错位及其涪江流域形成的最早沉积记录的年代大约为3Ma，估算映秀-北川断裂带和灌县-安县断裂带北东段上新世-第四纪以来的平均走滑速率分别为1．67mm／a和1．33mm／a，而龙门山断裂带北东段的长期走滑速率至少为3．0mm／a。

英文摘要：

River responses to active tectonics produce characteristic geomorphological features manifesting surface tectonic deformation. The Longmen Shan（LMS） range, which constitutes the eastern border of the Tibetan Plateau is characterized by a steep topographic transition between the high Tibetan Plateau in the west and the low Sichuan Basin in the east. Several large river systems, such as Qingyi Jiang, Min Jiang, Fu Jiang and Jialing Jiang rivers, developed from southwest to northeast along the LMS range. This study presents an examination to evaluate how known Plio-Quaternary tectonics have conditioned the drainage network patterns. The drainage network patterns and morphological features were identified and derived from satellite images and DEM （Digital Elevation Model） data. Our results suggest that the drainage system of LMS is variously controlled by Late Cenozoic tectonics. In the southwest segment of LMS, the fault-related folds were propagated during Plio-Quaternary. Lateral propagation and vertical uplift of active folds has forced an original longitudinal drainage system to develop as a transverse system. Accordingly,the southwest LMS is characterized by a strong geometric relationship between the main tectonic structures and the directions of stream channels. At northeastern part of LMS, stream networks were displaced dextrally along the fault zone,stream capture and reorganization can be found between the Leigu and Qushan towns, Beichuan County,which has been identified by the presence of wind gaps,fluvial elbows. Lateral offset of the Jianjiang River,one tributary of the Fujiang River,is about 3.8km. Systematic offset streams with displacements of 5km and 4km indicate right-lateral strike-slip motion at a rate of about 1.67mm/a and 1.33ram/a, respectively, along the NE-SW trending Yingxiu-Beichuan and Guanxian-Anxian fault zones. The average slip rate of the northeastern LMS fault zone is at least 3.0mm/a. Our study demonstrates the potential for using drainage network pattern as tectonic mark