高寒草甸典型小流域雨后土壤水分空间变异特征  

The Spatial Heterogeneity of Soil Moisture after Raining in Representative Gully Catchment of the Alpine Meadow

作　　者：张春敏[1] 王根绪[1,2] 王军德[1] 龙训建[1] 

机构地区：[1]兰州大学资源环境学院,兰州730000 [2]中国科学院山地灾害与环境研究所,成都610041

出　　处：《水土保持研究》2007年第6期10-14,共5页Research of Soil and Water Conservation

基　　金：国家自然科学基金项目(90511003);中国科学院知识创新工程重点项目(KZCX1-SW-04)资助

摘　　要：利用地统计学的Kriging空间内插法研究寒区典型小流域雨后土壤水分空间变异及分布情况;分析了0～50 cm土壤层的平均土壤水分与剖面土壤水分的空间分布特征。结果表明：0～10 cm、10～20 cm、20～30 cm、30～40 cm和40～50 cm五层土壤水分和流域平均土壤水分最佳拟合模型为球状模型;在小流域尺度范围内,五层土壤水分具有中等空间变异性,其块金系数为43.7%、58.9%、53.0%、71.6%和68.1%,流域平均土壤水分的块金系数为38.4%,0～10 cm1、0～20 cm、20～30cm三层土壤水分相关度明显小于30～40 cm和40～50 cm两土层土壤水分,说明表层土壤水分受降雨因素干扰明显,而深层土壤含水量相关性比较稳定。通过分析,得出雨后流域土壤水分空间分布主要受水分入渗、地形、植被覆盖、海拔等因素的影响。利用半方差函数分析得出流域土壤水分的有效变程在938～1469 m之间,40～50 cm土层土壤水分变程最大,为1469 m;10～20 cm土层土壤水分变程最小为938 m。通过确定半方差函数、比较变量的空间变异性及空间变异程度,得出在小流域内土壤水分半方差函数模型总体上拟合效果较好。Using a typical case of small watershed in an alpine meadow, this paper studied the spatial heterogeneity of soil moisture after raining using GIS software and the Kriging interpolation method. The results for soil moisture modeling are as follows： the optimal model for the soil layer 0～10cm, 10～20cm, 20～30cm, 30～40cm and 40～50cm below the surface are spherical. The results for spatial heterogeneity are as follows： within the watershed, the five soil layers within 0～50cm below the surface and the mean soil moisture have moderate spatial heterogeneity. The nugget coefficient are 43.7%,58.9% ,53.0%, 71.6%, 68. 1% and 38. 4%, respectively, Furthermore, the Simi-variance function and Kriging interpolation map of soil moisture both indicated spatial structure characteristics well. The ranges of the five layers were 1 375 m, 938 m, 1 428 m, 1 313 m and 1 469 m, respectively. The soil layer within 40～50 cm had the maximum range, and the layer within 10～20 cm had the minimum range.

关 键 词：高寒草甸 土壤水分 KRIGING插值 空间变异 

分 类 号：S152.7[农业科学—土壤学]