【摘要】 岷江中、上游从我国地势的第一阶梯穿入第二阶梯,是中国西部地质、地貌、气候的陡变带,因而研究其下蚀率具有重要的理论和实际意义。利用河流阶地与阶地形成年龄间的线性关系分别研究了岷江上游和中游几个河段的河流下蚀率,通过计算分别得出岷江上游和中游几个河段的河流下蚀率,在此基础上对岷江上游和中游的几个河段的下蚀率作了对比,得出岷江上游几个河段的年平均下蚀率(1.40 mm/a)大于岷江中游几个河段的年平均下蚀率(1.08 mm/a)的结论,并分析了产生这种现象的原因。更多还原

【Abstract】 Minjiang River is a very important tributary of Changjiang River and is located in eastern margin of Tibetan Plateau which is an important constitute of geotectonic units of China.It is also a changed area of geology,geomorphology and climate.The authors according the linear relation between river terrace and river incision studied the incision rate of Minjiang River’s upper and middle reaches,and reached a conclusion that the average incision rate of Minjiang River’s upper reaches is 29.62% larger than the average incision rate of Minjiang River’s middle reach.The reasons are the difference in the channel gradients of Minjiang River’s upper reaches and middle reaches,and the elevation movement of earth crust which is different under the river channel.更多还原