天山北麓河流纵剖面与基岩侵蚀模型特征分析  

The Longitudinal Profiles of the Ten Rivers in North Tianhan Mountains and Their Tectonic Significance

作　　者：赵洪壮[1,2] 李有利[1,2] 杨景春[1] 吕红华[1,2] 

机构地区：[1]北京大学城市与环境学院,北京100871 [2]北京大学地理科学中心地表过程分析与模拟教育部重点实验室,北京100871

出　　处：《地理学报》2009年第5期563-570,共8页Acta Geographica Sinica

基　　金：国家自然科学基金项目(40571013)~~

摘　　要：本文提取分析天山北麓10条河流的纵剖面,通过函数拟合纵剖面形态特征,同时运用基岩侵蚀力模型来研究河流纵剖面形态的发育演化过程,来揭示河流纵剖面的发育与构造活动之间的内在关系。研究表明:天山北麓河流地貌地形发育阶段处于河流侵蚀作用强烈的前均衡状态时期。塔西河的纵剖面凹曲度最大,向东西两侧河流凹曲度依次降低,乌鲁木齐河与四棵树河凹曲度最小,河流的凹曲度(θ)和河道坡度(KS)的数值分布规律与所对应构造部位晚更新世以来的抬升速率和地壳缩短速度相一致,排除时间、气候因素和基岩性质影响因素后,发现晚更新世以来天山北麓河流纵剖面形态变化主要受构造抬升作用的影响。In this paper we carry out a study on the longitudinal profile of the 10 rivers in the north Tianshan Mountains, by fitting the characteristics of the river longitudinal profile using four function patterns, and analyzing the evolution process of the 10 rivers＇ longitudinal profile based on the stream-power incision model. We reveal the relationships between the evolution process of the river and the tectonic activity. Our study indicates that the concavity index of the Taxihe River is the greatest one among the 10 rivers, and the concavity indexes of the other rivers become small one by one in turn on both sides, so the concavity indexes of the Urumqi River and the Sikeshuhe River are the least ones comparatively. The evolution phase of the river topographic form is the pre-steady-state topography. Consequent analysis reveals that the upward-convex features of the profiles and slope-area plots can be explained by the elevation of the bedrock profile getting higher and higher and the uplift being beyond the incision around the target area.

关 键 词：河流纵剖面 基岩侵蚀模型(S-A模型) 河流凹曲度 河道坡度 构造运动 天山 

分 类 号：P931[天文地球—自然地理学]