The Characteristics Of Glacier Trough And Its Influencing Factors In The Middle Section Of Tenasserim Chain

Since the Earth's history entered the Quaternary period,the global climate change has become the most prominent feature.During this period,glacial and interglacial periods alternated repeatedly,leaving abundant glacial relics in the glaciation area.The trough valley glaciers as glaciation zone distribution,one of the largest and the most typical glacial chronology,the space distribution,morphological characteristics,erosion degree and then explores its influence factors,not only helps to analyze developmental characteristics of glacial trough valley,and it further reveals the qinghai-tibet plateau mountain the evolution of the quaternary glacial development history.Tenasserim chain is located in the transition zone from Qinghai-Tibet Plateau to Yunnan-Guizhou Plateau and in the southwest monsoon channel.During the Quaternary period,the region underwent multiple glaciations and formed many tall and typical glacial troughs.Taking the glacial troughs in the middle section of Taanniantaweng Mountain as the research object,this paper extracted and analyzed the elevation data of 3127 cross-sections of glacial troughs and 128132 structural points by using semi-automatic means of Arc Map and Matlab software.Power function fitting value,V-index value,morphology ratio and multivariate correlation analysis were used to analyze the basic characteristics of glacial troughs in the study area,and the spatial and temporal distribution of glacial troughs in the study area and the main restrictive factors affecting the development of glacial troughs were obtained.The main research conclusions are as follows:(1)Based on DEM,Locaspace Viewer image and field survey,206 glacial troughs are developed in the middle part of Tenasserim chain,and 11 large glacial troughs are located near Nujiang River.Trough valleys are mostly U-shaped or U-shaped,with a length of4.5-26 km,a width of 4-5km,a depth of 200-500m(700-800 m for some trough valleys),and an altitude of 5730-3274 m.(2)The variation trend of b value and V-index value along the longitudinal direction of trough valley is the same,and there are three main manifestations: b value and V-index value gradually increase,and the shape of trough valley gradually develops to "U" shape;b value and V-index value gradually decrease,and the groove and valley morphology gradually develop to "V" shape.The b value and V-index value of the composite trough first increased and then decreased,and the shape of the trough generally showed a "U" shape at first and then a "V" shape gradually.(3)In space,the b value and V-index value of the study area show a certain difference.Along the main ridge,the b value and V-index value of the northeast slope are greater than that of the southwest slope.(4)The differences in the spatial distribution of glacial trough morphology in the study area may be due to the combined effects of many factors,such as the characteristics of glaciers,the topography of glaciation area and the lithology of bedrock.Among them,the average slope of glaciation area and the average glacier size in each mountain area are the main factors that cause the difference in the distribution.