构造地形指标的发展对于构造运动的量化研究具有重要意义。白龙江流域位于青藏高原与西秦岭造山带之间的过渡地带,对该流域地貌是否处于构造隆升与河流侵蚀的均衡状态,以及内部构造活动性的差异如何等问题尚缺乏细致研究。基于Arcgis9.3与ASTERGDEM数据,提取了白龙江流域32条支流的纵剖面,拟合其最佳函数形态,并利用基岩侵蚀模型提取了各个支流的标准化陡峭指数、凹曲度及拟合系数值,来揭示白龙江流域河流对构造运动的响应特征。结果表明:白龙江流域河流拟合函数以指数函数为主,河流大多发育处于侵蚀作用强烈阶段;中上游地区标准化河流陡峭指数值较下游地区偏大,凹曲度值和拟合系数中上游较下游值偏小,反映了白龙江流域中上游与下游构造活动强度的差异性;32条支流的凹曲度大部分小于均衡状态经验平均凹曲度值(0.49),表明白龙江流域地貌形态发育大部分还没有达到均衡阶段。
Geomorphic indices have been widely used for studying relative active tectonics. The research about tectonic activity can be quantified with the development of mathematical models for river and stream-power incision model. Bailongjiang drainage system is located in the transition area between Tibetan Plateau and West Qinling Mountain. There is little research about this drainage basin on that whether it is in a steady-state or what is the difference about the activity. We carry out a study on the longitudinal profile of the 32 rivers,by fitting the characteristics of the river longitudinal profile using four function patterns,and analyzing the evolution process of the 32river's longitudinal profile based on the stream-power incision model. We can concluded that tectonic activity play an important role in this region's geomorphic indices and the upward-convex features of the profiles,the evolution phase of the river topographic form have not got to the steady state.