青藏高原东缘中晚更新世以来河流下切速率研究

Studies of River Incised Rate in the Eastern Margin of Tibetan Plateau Since Late Pleistocene

本文通过分析汇总大量的河流阶地拔河高度和测年资料,对青藏高原东缘中晚更新世以来河流下切速率进行了计算,并绘制了河流下切速率等值线图,以反映河流下切速率的空间分布,结果表明,在青藏高原的东部端、东南端以及龙门山一带下切速率较快。将此结果与活动断裂的分布和现代GPS速度场进行了对比分析,发现河流下切速率较快的地方与活动断裂分布地区及GPS速度发生突变地区基本一致。

The river incision rates mark a crucial page in geomorphology studies. The paper summarizes a raft of river terraces tug heigh and dating information. Meanwhile, river incision rates in the eastern Tibetan Plateau since the Late Pleistocene have been calculated and the river incised rate contour map has been plotted to reflect spatial distribution of river incised rate in the eastern margin of the Tibetan Plateau since the late Pleistocene. Comparing it with the distribution of active faults and modern GPS velocity field, we found the results of places with a faster rate of river incision, active faults distribution areas,and regions occurring GPS speed mutation are consistent. Thus we can draw the conclusion that rapid rivers incision is attributable to tectonic movement.