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冰川槽谷(“U”形谷)是冰川与下伏基岩相互作用的结果,是典型的冰蚀地形,对其定量化研究是了解冰川作用过程以及冰川槽谷演化过程的重要途径.二次多项式(y=A+Bx+Cx2)和幂函数(y=axb)是定量描述冰川槽谷形态的两种较普遍的方法,二次多项式可以描述冰川槽谷的整体形态且不需要考虑高程基准面的选择,但是该方法不能用于槽谷间的比较且其只能较准确地描述接近抛物线的横剖面;幂函数不但可以反映不同作用过程形成的谷地,还能在不同横剖面间进行比较,但幂函数在应用过程过会受到坐标原点选取、对数变化、后期堆积以及横剖面不对称的影响,其运用过程更加复杂.此外,相同的幂函数指数b可能指示不同的槽谷形态,形态比率FR的引入并与指数b结合起来使对槽谷形态的描述更加全面.从冰川动力和外部环境方面出发,影响槽谷形态的因素主要有冰川作用时间、基岩的抗侵蚀能力、岩性的分布以及裂隙、冰量、气候、构造和冰川性质,后三者对槽谷形态的定量化影响需要进一步进行探讨.运用不同地区槽谷形态参数所做b~FR图探讨了山地冰川槽谷的发育模式,发现山地冰川槽谷存在对应于两种不同冰川性质的相反的发育模式,但是由于岩性、气候等其他因素的影响,造成了冰川槽谷发育模式有时出现了不对应的情况.
Glacier trough (“U” shaped valley) is the result of the interaction between glacier and underlying bedrock. It is a typical ice-eroded terrain. The quantitative study of it is an important way to understand the process of glacier and the evolution of glacier valley . The quadratic polynomials (y = A + Bx + Cx2) and the power function (y = axb) are the two most common methods for quantitatively describing the morphology of glacier troughs. Quadratic polynomials can describe the overall shape of glacier troughs and do not require Considering the choice of elevation datum, this method can not be used for the comparison between troughs and valleys, and it can only describe the horizontal section close to the parabola accurately. The power function can not only reflect the valleys formed by different processes, However, the application process of the power function is more complicated due to the choice of coordinate origin, logarithmic change, late accumulation and cross-section asymmetry. In addition, the same power function index b may indicate different slots The introduction of valley morphology and morphological ratio FR combined with the index b makes the description of trough morphology more comprehensive.From the aspect of glacier power and external environment, the factors affecting the shape of trough valley mainly include glacial action time The anti-erosion ability, lithology distribution, fissure, ice volume, climate, structure and glacier properties of bedrock, the quantitative influence of the latter three on trough valley shape need to be further discussed.Using the parameters of trough valley shape in different regions ~ FR map to explore the developmental pattern of glacier troughs in the mountains. It is found that the glacier troughs have the opposite development pattern corresponding to two different glacier properties, but due to the influence of lithology, climate and other factors, the development of glacier troughs Occasionally, patterns do not correspond.