Spatial heterogeneity of soil moisture in alpine meadow area of the Qinghai-Xizang Plateau

In this paper geo-statistical theory and methods are used to study the spatial heterogeneity of soll moisture characteristics in shallow profile(0-40 cm) of alpine meadow areas(110 m×90 m) in the Qinghai-Xizang Plateau.The 352 sampling points are fixed in total Using the grid sampling method(10 m×10 m space).The results show that in alpine meadows 0-30 cm depth of coverage area,there is a high degree of spatial heterogeneity of soil moisture.Within 87.3%-74.9% spatial heterogeneity,part of the spatial autocorrelation is at 0-30 cm depth.The auto-correlation factors at 10-201 m scale play an important role in the 0-30 cm soil moisture spatial heterogeneity.But spatial heterogeneity of soil moisture at the layer of 3040 cm depth can be controlled by the random and auto-correlation factors.With the increase of depth the fractal dimension D has a gradually increasing trend.The worthy noting is that the random factor will increase at soil depth for soil moisture spatial heterogeneity.From the C0/(C+C0) comparable values of soil four layers,the minimum value is in the lowest level of this 10-20 cm,the level of system variables is shown in the highest degree of spatial autocorrelation.Soil moisture content of the layer 0-30 cm of alpine meadows area is affected by precipitation,vegetation growth,root distribution,soil characteristics and impacts of human interference et al.