唐古拉山中西段冰川槽谷形态及其影响因素分析

冰川槽谷作为典型的冰川侵蚀地貌，研究其形态特征和影响因素有助于更全面地认识冰川发育模式和侵蚀特征。本文以唐古拉山中西段为研究区，运用V指数模型和地理探测器模型，分析探讨了区内冰川槽谷形态发育特征，并对其影响因素进行了研究。结果表明：冰川槽谷横剖面的V指数与幂函数b值在槽谷对称的情况下可以相互替代，且典型冰川槽谷横剖面的V指数介于0.20~0.43之间。研究区保存着“箱形”形态的冰川槽谷，其V指数具有接近于1的特征。区内冰川槽谷横剖面V指数<0.20的占比19%，V指数介于0.20~0.43之间的占比48%，V指数>0.43的占比33%，表明研究区内呈典型“U”形的槽谷数量最多。此外，北坡主要发育典型“U”形的冰川槽谷，占比高达60%，而南坡各种形态的槽谷数量相当。研究区内山谷冰川发育区、过渡区槽谷呈典型“U”形的占比最多，而冰帽发育区槽谷近似“箱形”的占比最多。应用地理探测器对影响冰川槽谷形态特征的因素进行评价，最主要的影响因素有冰川作用区面积因素和冰川作用正差因素，其次是岩性因素，再次是坡度和地形起伏度因素，最后是冰川性质和槽谷朝向因素。冰川作用区面积因素和坡度因素的交互作用对冰川槽谷形态特征的影响最为显著。

Analysis on the shape of glacial valley and its influencing factors in the middle and west section of Tanggula Mountain

Glacial valley is a typical landform formed by glacial erosion. Studying the morphological characteristics of the cross-section of the glacier valley is helpful to distinguish the causes of different valleys and analyze the erosion process and erosion capacity of the glacier. Glacial erosion valley has many morphological characteristics. In addition to the most common glacial valley being U-shaped valley， box shaped and inverted trapezoidal valley forms are also developed. In the previous studies， researchers mostly focused on qualitative and quantitative analysis of the morphological characteristics of the partial U-shaped valley， while few quantitative studies on the morphological characteristics of other forms of valley； At the same time， the specific performance of the wide and shallow valley of Tanggula Mountain can be further deepened. When Zimmer studied the Quaternary glacial erosion geomorphologic features of the Sierra Nevada in the United States， he proposed a V-index （V） model to quantitatively express the glacial valley morphology， which proved that this method has higher accuracy than the power function method and the quadratic polynomial method in describing the glacial valley morphology. Geographic detectors can be used to detect the spatial differences of geographic attributes and reveal the driving factors behind them. Its advantages are： （1） the types of detection data can be qualitative or quantitative； （2） The interaction of two factors on the dependent variable can be detected. This method has been well applied in many geographical studies. As an important glacier development area in the central part of the Qinghai Tibet Plateau， Tanggula Mountain is an ideal mountain for studying the morphological characteristics of glacier valleys. In addition， due to the significant differences in the terrain， glacier development and lithology in the region， and the particularity of the geographical location， the cross-sectional characteristics of the glacier valley in the study area have certain spatial heterogeneity. Based on the above research background， this paper selects the typical glacier valley in the middle and west section of Tanggula Mountain as the research object， and analyzes the morphological characteristics of the glacier valley in the research area and the main control factors affecting the development of the glacier valley based on the V model and the geographical detector method. The analysis results are helpful to understand the development characteristics and erosion degree of continental glaciers and the specific characteristics of wide shallow valley. The results show that： （1） the V and the power function b value of the cross section of the glacier valley can be replaced each other， and the V of the cross section of the typical glacier valley is between 0.20 and 0.43. （2） There are “box shaped” glacial valleys in the study area， whose V is close to 1. （3） 19% of the cross-section V of the glacier valley in the study area is less than 0.20； The proportion of V between 0.20 and 0.43 is 48%； The proportion of V > 0.43 is 33%， indicating that the number of typical U-shaped valleys in the study area is the largest. In addition， the north slope mainly develops typical glacial valleys， accounting for 60%， while the south slope has the same number of valleys in various forms. （4） In the study area， the typical U-shaped valleys in the valley glacier development area and the transition area account for the most， while the “box shaped” valleys in the ice cap development area account for the most. （5） Geographical detectors are used to evaluate the factors that affect the morphological characteristics of glacial valleys. The most important factors are the area of glaciation area and the positive difference of glaciation， the second is the lithologic factor， the third is the slope and topographic relief， and the last is the glacial nature and the direction of the valley. The interaction of the area factor and the slope factor in the glaciation zone has the most significant effect on the morphological characteristics of the glacier valley.