西南喀斯特地区土壤饱和导水率及其影响因素研究

Soil Saturated Hydraulic Conductivity and Its Influential Factors in Southwest Karst Region of China

通过对西南喀斯特地区典型土壤的饱和导水率的分析，研究了喀斯特地区不同植被退化类型下土壤的饱和导水率及其影响因素。结果表明，西南喀斯特地区不同植被退化类型下土壤的饱和导水率存在着明显的差异，原状土表层饱和导水率在27．2×10^-4～50．8×10^-4cm／s之间，一般未经人为干扰的原始森林土壤饱和导水率〉人为干扰形成的灌丛土壤〉农业用地；在土壤剖面中自上而下饱和导水率明显降低；扰动土壤表层饱和导水率在0．27×10^-4～1．53×10^-4cm／s之间，明显低于原状土壤，仅为原状土壤的0．9％～3．0％。喀斯特地区影响土壤饱和导水率的主要因素有土壤容重、土壤孔隙度、土壤有机质含量、土壤质地等。主成分分析结果表明，影响原状土饱和导水率的主要因素为土壤质地和土壤孔性，而土壤孔性是影响扰动土壤导水率的主导因素。

The soil saturated hydraulic conductivity in different vegetation degeneration type and its influential factors in southwest karst region of China were studied. The results showed that the soil saturated hy- draulic conductivity in different vegetation degeneration type had obvious discrepancy, and it was ranked as follows： forest soil, low-growing bushes soil, farmland soil. The range of the undisturbed surface layer＇s saturated hydraulic conductivity was between 27.2×10^- and 50.8 ×10^- cm/s. The disturbed surface layer＇s saturated hydraulic conductivity was between 0.27×10^- and 1.53 ×10^-cm/s. Soil bulk density, soil porosity, the soil organic content and soil particle composition were the important impact factors to soil saturated hydraulic conductivity. The factor analysis showed that soil porosity and soil texture were the major factors to the undisturbed soil saturated hydraulic conductivity. But soil porosity was the domi- nant impact factor of the disturbed soil saturated hydraulic conductivity in karst region.