青藏高原坡面冻土土壤水分空间变异特性

发布时间：2018-02-10 13:15

本文关键词： 青藏高原坡面尺度多年冻土土壤水分空间变异特征　出处：《水科学进展》2017年01期 　论文类型：期刊论文

【摘要】：为深入揭示坡面冻土水分运移规律及其主要影响因子,以青藏高原巴颜喀拉山北坡为例,结合冻融变化过程,研究不同地形条件冻土土壤水分空间变异特征,利用分类回归树模型(CART)和典范对应分析(CCA)识别影响坡面冻土土壤水分空间异质性的主控因子及其相互作用关系。研究结果表明:1受坡面地形与冻融过程影响,冻结期坡面冻土土壤水分侧向流动减弱,以垂直迁移为主,上坡位含量高于下坡位,反之,融化期上坡位含量则低于下坡位。2影响坡面冻土土壤水分的主要环境因子为高程、土壤质地、土壤温度和植被覆盖度,但在不同冻融阶段下其影响因子存在差异,在冻结状态下主要因子为高程、土壤质地和土壤温度,其相对贡献率分别达到19.97%、19.45%和9.56%;在融化阶段下主要因子为高程、植被覆盖度和土壤质地,其相对贡献率分别为37.4%、14.9%和10.7%。3 0~20 cm浅层深度上影响坡面冻土土壤水分的主要因素为坡度、高程和植被覆盖度,其相关系数分别高达0.941 2、0.903 9和0.563 1;中下层深度上其主要影响因素较为复杂。
[Abstract]:In order to reveal the water migration law of frozen soil on slope and its main influencing factors, taking the northern slope of Bayan Kara Mountain in Qinghai-Xizang Plateau as an example, the spatial variation characteristics of soil moisture in frozen soil under different topographic conditions were studied in combination with the process of freezing and thawing. The classification regression tree model (CARTT) and canonical correspondence analysis (CCA) were used to identify the main controlling factors and their interaction relationships affecting the spatial heterogeneity of soil moisture in permafrost. During the freezing period, the lateral flow of soil water in permafrost was weakened, the vertical migration was dominant, the content of soil water in the upper slope was higher than that in the downhill, on the contrary, the content of soil water in the upper slope in the thawing period was lower than that in the downhill. 2. The main environmental factor affecting the soil moisture of the frozen soil on the slope was elevation. Soil texture, soil temperature and vegetation coverage are different in different freezing and thawing stages, and the main factors are elevation, soil texture and soil temperature in frozen state. The relative contribution rate was 19.977.45% and 9.56.The main factors were elevation, vegetation coverage and soil texture, and the relative contribution rates were 37.414.9% and 10.73.30 cm, respectively. The correlation coefficients of elevation and vegetation coverage were as high as 0.941 2 ~ 0.9039 and 0.563 1, respectively, and the main influencing factors on the depth of middle and lower layers were complex.
【作者单位】：中国科学院西北生态环境资源研究院冻土工程国家重点实验室;重庆市国土资源和房屋勘测规划院;
【基金】：中国科学院重点部署项目(KZZD-EW-13) 中国博士后科学基金资助项目(2016T90962)~~
【分类号】：S152.7;P642.14

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