Spatial variability of soil moisture at typical alpine meadow and steppe sites in the Qinghai-Tibetan Plateau permafrost region
Spatial variability of soil moisture at typical alpine meadow and steppe sites in the Qinghai-Tibetan Plateau permafrost region
复制标题
DOI：
10.1007/s12665-010-0716-y
复制
发表时间：
2011-06
影响因子：
2.8
通讯作者：
Zhaoping Yang;Ouyang Hua;Xian-zhou Zhang;Xingliang Xu;Cai-ping Zhou;Wen-bin Yang
中科院分区：
文献类型：
--
作者：
Zhaoping Yang;Ouyang Hua;Xian-zhou Zhang;Xingliang Xu;Cai-ping Zhou;Wen-bin Yang
多年冻土退化有可能显著改变土壤湿度。本研究的目的是评估土壤水分的变异性在多年冻土区使用地质统计学技术。试验于2008年8月在青藏高原多年冻土区高寒草原和草甸进行。采用频域反射仪对0-10、10-20、20-30和30-40 cm 4个土层深度进行了分析，在10 m × 10 m网格内采样80个点。土壤水分分析采用经典统计学来适当地描述集中趋势和分散，然后使用地统计学来描述空间变异。经典统计方法表明，多年冻土区土壤含水量呈正态分布。高寒草甸的平均表层土壤含水量高于高寒草原。半变异函数表明，高寒草原土壤水分变异性大于高寒草甸，且随深度增加而减小。与高寒草甸相比，高寒草原的块金值较低（0.1-4.5）。高寒草原土壤水分具有高度结构化的空间变异性，空间异质性达93.4%以上，变幅随深度的增加而减小。高寒草甸土壤含水量具有中等的空间依赖性，其变化范围为51.3- 169.2m，随深度增加而增加。
Permafrost degradation has the potential to significantly change soil moisture. The objective of this study was to assess the variability of soil moisture in a permafrost region using geostatistical techniques. The experiment was conducted in August 2008 in alpine steppe and meadow located in the Qinghai-Tibetan Plateau permafrost region. Four soil depths (0–10, 10–20, 20–30 and 30–40 cm) were analyzed using frequency domain reflectometry, and sampling made of 80 points in a 10 m × 10 m grid were sampled. Soil moisture was analyzed using classical statistics to appropriately describe central tendency and dispersion, and then using geostatistics to describe spatial variability. Classical statistical method indicated that soil moisture in the permafrost region had a normal distribution pattern. Mean surface soil moisture in alpine meadow was higher than that in alpine steppe. The semivariograms showed that soil moisture variability in alpine cold steppe was larger than that in alpine meadow, which decreased with depths. Nugget values in alpine steppe were low (0.1–4.5), in contrast to alpine cold meadow. Soil moisture in alpine steppe had highly structured spatial variability with more than 93.4% spatial heterogeneity, and the range decreased with depth. Soil moisture content in alpine cold meadow had a moderate spatial dependence with a range of 51.3–169.2 m, increasing with depth.