River geomorphic parameters and their neotectonic significance of the northern piedmont of the Zhongtiao Mountain
XU Wei;YUAN Zhao-de;LIU Zhi-cheng;GAO Zhan-wu;China Earthquake Disaster Prevention Center;
Based on the Digital Elevation Model and Geographic Information System technology,we extract and analyze the geomorphic parameters which include stream length-gradient index,channel steepness index and hypsometric integral of the northern piedmont of the Zhongtiao Mountain,Shanxi Province,China. The results showed that the values of stream length-gradient index,channel steepness index and hypsometric integral index were increased gradually from north to south in general and the high values of the parameters were all distributed in the south part between Yongji and Haizhou. The knickpoints which represent the spatial or temporal adjustment of tectonic movement are densely distributed in the part south of Haizhou whereas in the part north of Haizhou the knickpoints were distributed sporadically. Comprehensively analyzing the main factors including rocks,precipitation and tectonics that affect geomorphic parameters,we reached the conclusion that tectonics is the major factor that controls the development of the watershed topographic features and the tectonic activity was increased gradually from the north to the south. The northern piedmont tectonic activity of the Zhongtiao Mountain is mainly controlled by the northern Zhongtiao Mountain Fault according to regional geological tectonic background. The field geological investigation combined with previous studies show that the north Zhongtiao Mountian Fault can be divided into the south section,the middle section,and the north section according to their different geometric trending and fault activities by Xiyaowen village and Mohe village. Fault slip rate which is an important index to judge fault activity in the middle section is higher than that in the south and the north sections and the maximum value is distributed in the south of Yongji. The tectonic activity of the north piedmont of Zhongtiao Mountain gained from geomorphic parameters is consistent with the fault activity since the late Quaternary. In the north section,as the weak fault activity,we can see the flat pediment which is retreated by the long-term erosion of the Zhongtiao Mountain is as wide as 10 km. However,in the middle section,steep mountain landforms are formed due to the constant strong tectonic activity,and they become more and more striking from the north to the south. The highest peak Snow Mountain which is located at the south of Yongji shows that in this part the fault is the most active,and this is consistent with the high value obtained from geomorphic parameters. Utilize the river geomorphic parameters as the study objects of the tectonic activity can effectively reflect the regional tectonic movement. It provides a new perspective for discussing the relative activity strength in river drainage.
【CateGory Index】： P931.1
【CateGory Index】： P931.1