摘要
龙门山位于青藏高原东缘,既是青藏高原周缘山脉中陡度最大的山脉,也是构造活动和地貌景观塑造最为强烈的地区之一。因此,该区域成为研究构造-地貌-水系之间相互关系的实验场。本文基于ASTER GDEM数据,提取了青藏高原东缘地区15条基岩河道的纵剖面,采用简单数学函数拟合河流纵剖面形态,并结合基岩水力侵蚀模型,分析龙门山不同位置的地形特征。本次研究获得以下几点认识:①通过对龙门山地区河流纵剖面的分析,龙门山整体上具有较高的隆升速率,导致这一地区强烈的河流侵蚀作用;②龙门山中段和南段的河流双对数图以上凸型为主,说明该区域尚未达到均衡状态,处于前均衡期;③龙门山北段的河流双对数图呈直线形态,说明该区域达到均衡状态,处于均衡期;④龙门山不同地区的水系发育特征,表明龙门山中段和南段具有更强的构造活动性、更高的隆升速率,龙门山北段则具有较弱的构造活动性、较低的隆升速率,并反映了青藏高原东缘的隆升作用具有明显的空间差异性。
The Longmen Mountains are located in the eastern margin of the Qinghai--Xizang （Tibet） Plateau It is not only the one which has the greatest transmutation of steepness among those around the QinghaiwXizang （Tibetan） Plateau, but also one of the areas where the strongest climate and tectonic activities have been happened. Thus, Longmen Mountains area has been one of the best places to study the relationships about tectonic--geomorphy--water system. With the ASTER--GDEM date, this article extracts the 15 longitudinal profiles of bedrock channels of the Eastern Qinghai--Xizang （Tibet） Plateau, and fits the longitudinal profiles with the simple mathematical function, then analyzes the topographic feature combined with stream-power incision model in different regions of the Longmen Mountains. The study draws the following conclusions ： ① based on the analysis of longitudinal profiles, the Longmen Mountains have high uplifting rate, which leads to the stronger river erosion in this area; ② in the central and southern sections of the Longmen mountains, most of logarithmic S--A plots are convex upward, therefore, these region have not been achieved the equilibrium state and are in the period of pre- equilibrium; ③ in the northern section of the Longmen Mountains, most of logarithmic S--A plots are straight lines, therefore, this region has been achieved the equilibrium state and is in the period of equilibrium; （~） the characteristics of drainage development in different regions of the Longmen Mountains show that the central and southern sections of the Longmen Mountains have the stronger tectonic activity and the higher uplifting rate; while the northern section of the Longmen Mountains has the weaker tectonic activity and the lower uplifting rate, which reflects the uplift of Eastern Qinghai--Xizang （Tibet） Plateau very different among areas.
出处
《地质论评》
CAS
CSCD
北大核心
2015年第2期345-355,共11页
Geological Review
基金
国家自然科学基金资助项目(编号41340005
41372114
41172162
40972083)
四川省教育厅科研项目(编号15ZB0085)的成果
关键词
水力侵蚀模型
河流纵剖面
地形均衡
构造运动
龙门山造山带
青藏高原东缘
stream-power incision model
longitudinal profile
steady topography
tectonic movement
Longmen orogenic belt
the eastern margin of the Qinghai--Xizang（Tibetan） Plateau
