山西太岳山小流域土壤水分空间异质性及其影响因子

发布时间：2019-02-28 08:07

【摘要】：以山西太岳山华北落叶松林地为主的小流域作为研究对象,采用地统计学方法结合地理信息系统(GIS)技术手段,研究了接石沟小流域土壤水分(0—60cm)的空间变异特征,以及植被分布和地形因子对其影响规律。结果表明:在时间稳定性的前提下,土壤水分含量和变异系数随土层加深逐渐降低。三层土壤水分半方差函数的最优拟合模型为球状模型,变程范围在1.1—1.4 km,均具有强烈的空间自相关性,其中0—20 cm和20—40 cm层土壤水分的空间异质性程度高于40—60 cm土层,以中间层的结构因素占总变异比例最大。自然结构因素(地形、母质、植被和土壤等)对不同土层土壤水分的总空间变异性起主导作用(81.4%—91.3%),而随机因素(取样误差、人为干扰等)的影响相对较小(8.7%—18.6%)。沿着集水线由西-东方向,从边缘的土壤水分高值斑块区逐渐过渡到明显的低值斑块区,梯度变化明显。研究发现,在植被覆盖异质性小的山地,土壤水分的空间异质性主要由地形因素引起,具体表现为其与坡向指数(TRASP)、坡度、海拔和土壤有机碳、全氮呈极显著相关关系(P0.01),而与植被指数(NDVI)呈弱的负相关关系。叠加分析显示,在阴坡、坡度较缓(15°)及高海拔叠合的区域土壤水分含量较高。研究结果可为山地人工林构建和植被恢复中土壤水资源的利用以及水分管理策略的制定提供理论依据。
[Abstract]:Based on the small watershed of Larix principis-rupprechtii forest land in Taiyue Mountain, Shanxi Province, the spatial variation characteristics of soil moisture (0-60cm) in Jieshigou small watershed were studied by means of geostatistics and geographic information system (GIS). And the influence of vegetation distribution and terrain factors on it. The results showed that soil moisture content and coefficient of variation decreased gradually with soil depth deepening on the premise of time stability. The best fitting model of three-layer soil moisture semi-variance function is spherical model, and the range of variation is 1.1 ~ 1.4 km, with strong spatial autocorrelation. The spatial heterogeneity of soil water in 0 ~ 20 cm and 20 ~ 40 cm layers was higher than that in 40 ~ 60 cm soil layers, and the structural factors in the middle layer accounted for the largest proportion of total variation. Natural structural factors (topography, parent material, vegetation and soil, etc.) play a dominant role in the total spatial variability of soil moisture in different soil layers (81.4% ~ 91.3%), while random factors (sampling error, sampling error) play a dominant role in the total spatial variability of soil moisture in different soil layers. The effect of human disturbance is relatively small (8.7% / 18.6%). Along the catchline from the west-east direction, from the edge of the high-value soil moisture patch gradually transition to the obvious low-value patch area, the gradient change is obvious. It is found that the spatial heterogeneity of soil water is mainly caused by topographic factors in mountainous areas where vegetation cover heterogeneity is small. The spatial heterogeneity of soil water is mainly caused by slope index (TRASP), slope, altitude and soil organic carbon. There was a very significant correlation between total nitrogen and vegetation index (NDVI) (P0.01), but a weak negative correlation with vegetation index. The superposition analysis showed that the soil moisture content in the overcast slope was higher than that in the overcast slope (15 掳) and superposed at high altitude. The results can provide a theoretical basis for the utilization of soil water resources and the formulation of water management strategies in mountain plantation construction and vegetation restoration.
【作者单位】：北京林业大学省部共建森林培育与保护教育部重点实验室;山西省太岳山国有林管理局好地方林场;
【基金】：国家林业公益性行业科研专项(201404213)
【分类号】：S714

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