基于ASTER-DEM的雅鲁藏布江下游差异抬升分析  

DIFFERENTIAL UPLIFT ANALYSIS OF THE DOWNSTREAM REACHES OF YARLUNG ZANGBO RIVER BASED ON ASTER-DEM

作　　者：辛聪聪 王运生[1] 洪艳 申通[1] 韩立明 赵逊 XIN Congcong;WANG Yunsheng;HONG Yan;SHEN Tong;HAN Liming;ZHAO Xun(State Key Laboratory of Geo-Hazard and Geo-Environment Protection,Chengdu Univerisity of Technology,Chengdu 610059;College of Earth Sciences,Chengdu Univerisity of Technology,Chengdu 610059)

机构地区：[1]地质灾害与环境保护国家重点实验室(成都理工大学),成都610059 [2]成都理工大学地球科学学院,成都610059

出　　处：《工程地质学报》2019年第4期832-841,共10页Journal of Engineering Geology

基　　金：国家重点研发计划项目(2017YFC1501000);国家自然科学基金(41877235)资助~~

摘　　要：雅鲁藏布江是东构造结的核心区域,为研究雅鲁藏布江大拐弯流域现今隆升发育现状,本文基于ArcGIS平台,对雅鲁藏布江下游大拐弯流域的ASTER-DEM30m面积-高程积分值(Hypsometry Index,简称HI法,是一种基于数字高程模型来获取流域演化特征及其构造活动响应指标的方法)进行计算,并结合构造、岩性、气候、第四系以及河流等基础资料探讨该地区隆升差异。结果表明:HI>0.43的隆升区主要集中在大拐弯缝合带以外的区域且分布与各断块中的三级夷平面具有较好的耦合性;而HI>0.60拉萨断隆隆升区分布范围最大,加拉白垒断隆分布最小,仅在大拐弯小范围分布;HI<0.43的侵蚀下切区,处于河流的一二级谷肩位置以及河流发育较为成熟的区域;林芝—派镇段区域内HI<0.35,以侵蚀下切为主。由以上得出:区内构造挤压作用依然存在,而气候、河流以及断裂带密度的影响是在构造背景下产生的,随着时间推移以上因素会逐渐抑制构造抬升作用,并且对侵蚀的促进作用在不同区域内表现不同;当构造作用发挥主要作用时,断块以隆升作用为主,HI>0.43;气候作用的影响使加拉白垒与南迦巴瓦峰处于隆升停滞,HI<0.43;林芝段HI<0.35说明在气候、河流发育以及断裂带密度的影响下会加大侵蚀的力度使得区域内以侵蚀下切为主,未有抬升迹象。整体上,在构造、气候、河流发育及断裂带密度综合影响下,隆升作用由雅鲁藏布江流域下游外部向内部逐渐减弱,而局部区域上的差异是由影响因素发挥作用的差异决定的。The Yarlung Zangbo River in Tibet is the core area of the eastern tectonic knot.This paper aims to study the current uplifting status of the Big Bend Region at Yarlung Zangbo River.It uses the ArcGIS platform.The research teams calculate the ASTER-DEM30 m area-elevation integral value of the Big Bend Region at the lower Yarlung Zangbo River.The Hypsometry Index is a method based on the digital elevation model to obtain the characteristics of river evolution and the corresponding response index of tectonic activity.It examines the uplift difference in the study area in combination with the basic data of structure,lithology,climate,Quaternary depositsand rivers.The results show that the uplift area with HI>0.43 is mainly located outside the Big Bend suture zone and its distribution is well coupled with theⅢ-grade planation plane in each block.While the distribution range of Lhasa fault uplift area with HI>0.60 is the largest,and the distribution area of the Gyalha Bair fault uplift area is the smallest,which is only distributed in a small range of the Big Bend Region.The eroded cutting area with HI<0.43 is located at theⅠandⅡgrade valley shoulders of the river and the mature area of rivers.The Linzhi-Paizhen section with HI<0.35 mainly manifests as erosion and down cut.It is concluded that the tectonic compressive action still exists in the study area,and the influence of climate,rivers and fault zone density are generated under the tectonic setting.The above factors would gradually inhibit the tectonic uplift with the passage of time,and the promotion effect of erosion is different in different regions.When the tectonic effect plays a major role,fault block is dominated by uplift with HI>0.43.The influence of climatic action led to the uplift stagnation for Gyalha Bair and Namjagbarwa Mountains,with HI<0.43.The Linzhi block with HI<0.35 indicates that the intensity of erosion will increase under the influence of climate,rivers and fault zone density.So the area mainly manifests as erosion and down cut,with n

关 键 词：面积-高程积分 DEM 东构造 雅鲁藏布江 

分 类 号：P542[天文地球—构造地质学]