青藏高原及周边山地第四纪山谷冰川长度与冰碛垄高度的相关
说明：文章内容仅供预览，部分内容可能不全。下载后的文档，内容与下面显示的完全一致。下载之前请确认下面内容是否您想要的，是否完整无缺。
青藏高原及周边山地第四纪山谷冰川长度与冰碛垄高度的相关性研究 摘要：重建第四纪冰川作用的范围是研究高原地貌演化的重要内容。我们从文献和野外工作中收集了关于青藏高原及周边山地的141组数据，数据包括冰碛垄的高度及其对应的古冰川的长度。这里的冰碛垄高度定义为由冰碛垄脊部到相邻河谷谷底高差的最大值。分析冰碛垄高度和古冰川长度的相互关系并对其进行回归，发现相对于终碛垄，侧碛垄的高度与古冰川长度有更好的相关性，相关系数平方为0.44，侧碛垄比终碛垄保存相对完好更能表示冰碛垄的原始形态。侧碛垄的高度与古冰川长度的相关性在干旱气候区比湿润气候区更紧密，前者相关系数平方为0.67，后者为0.32，这是因为干旱气候区的地貌保存更好，湿润气候区的高降水及冰川消融对冰碛地貌有更严重的流水侵蚀和物质搬运，从而导致对冰碛垄的相对更为严重的破坏。全新世冰期形成的侧碛垄的高度与冰川长度的相关系数为0.85，相关性比之前的冰期都要好，因此对于终碛垄被破坏以致无法界定末端位置的古冰川，通过侧碛垄的高度来推测当时冰川的长度有重要意义。对两个线性关系比较明显的模型进行回归误差分析表明，干旱气候区的侧碛垄高度推测对应冰川长度的误差为38％，全新世冰期模型的回归误差为30％。本文是评估冰川规模对地貌演化的初步工作，但对于后继工作有着重要意义。 Abstract：Reconstructions of the extent of Quaternary glaciations provide important knowledge of landform evolution on the Tibetan Plateau. The heights of moraines and the lengths of corresponding former glaciers in Tibet and its surrounding mountains were statistically analyzed using values for 141 observations collected from the literature and field measurements. The height of a moraine is defined as the difference between the elevation of the highest point of a lateral moraine and the elevation of the nearby valley bottom. The results show that the height of a lateral moraine is more closely related to the length of the former glacier than with the height of its end moraine. The lateral moraine was preserved better and more accurately represents the original shape of the moraine. The correlation between the height of a moraine and length of a glacier from lateral moraines in arid areas is better than that in maritime areas. This results from better preservation in arid areas. The high precipitation in the maritime areas results in stronger fluvial erosion and mass movement, and consequently is very effective in modifying and/or destroying moraines. The correlation between heights and lengths of lateral moraines is much better for Holocene than for older glaciations. Therefore, the correlation of the heights of Holocene lateral moraines to the lengths of glaciers is helpful for reconstructing the extent of Quaternary Glaciation when end moraines are not preserved. This in turn is a first step towards assessing the relative importance of glaciers in landscape evolution across orogens. 本文来源：https://www.wddqw.com/doc/c144a3d507a1b0717fd5360cba1aa81144318f85.html