| 摘要: |
| 【目的】研究扰动地表下不同长度坡面土壤物理性质及水分入渗特征，为合理开发利用土地资源提供科学依据。【方法】通过野外调查与室内分析相结合的方法，于2013年选择具有代表性的坡度为15°的地块，设置6个处理：长度20 m人工扰动地表坡面、长度20 m自然坡面、长度40 m人工扰动地表坡面、长度40 m自然坡面、长度60 m人工扰动地表坡面、长度60 m长自然坡面，测定不同处理土壤的物理性质及水分入渗过程，采用常用的4种入渗模型（Kostiakov模型、Horton模型、Philip模型、通用经验公式模型）对土壤入渗过程进行拟合，并分析土壤水分入渗特征指标（初始入渗速率、平均入渗速率、稳定入渗速率、90min累计入渗速率）与理化性质的相关性。【结果】相同措施处理下，坡长越长，土壤体积质量越小。在扰动地表和自然坡面下，总孔隙度和非毛管孔隙度的差异不显著，扰动地表坡面土壤初始含水率表现为60 m坡长>40 m坡长>20 m坡长。采用常用入渗模型进行拟合时，Kostiakov模型的拟合精度在0.646~0.963，平均值为0.886；Horton模型的拟合精度在0.878~0.981，平均值为0.953，Philip模型的拟合精度在0.317~0.709，平均值0.592，通用经验公式模型的拟合精度在0.765~0.970，平均值为0.920，可知Horton模型拟合精度最大。不同坡长下，自然坡面的土壤入渗特征指标大于扰动地表坡面。相关性分析结果显示，土壤水分入渗特征指标与土壤体积质量呈显著或极显著负相关，与非毛管孔隙度呈正相关，与土壤通气度呈极显著正相关；而毛管孔隙度、总孔隙度、自然含水率、有机质与土壤水分入渗特征指标相关性不显著。【结论】20 m坡长下，扰动地表不利于改善土壤渗透性，扰动地表处理措施下的土壤水分入渗能力弱于自然坡面；60 m坡长下，土壤通气性和透水性较好，土壤水分入渗能力强。Horton模型是分析和预测扰动地表下不同坡长土壤水分入渗的最优模型。 |
| 关键词: 扰动地表 不同坡长 土壤物理性质 水分入渗 |
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| 基金项目:水利部公益性行业科研专项经费项目（201301048）；国家自然科学基金项目（41271291） |
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| Soil physical properties and infiltration characteristics of different slope lengths under disturbed surface |
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GUO Xiaomeng,HE Binghui,YAO Yun,et al
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| Abstract: |
| 【Objective】This study investigated soil physical properties and water infiltration characteristics in disturbed surface with different slope lengths to provide scientific basis for rational development and utilization of land resources. 【Method】Through field investigation and laboratory analysis methods,a representative block with 15 ° slope was selected in 2013 and six treatments were set up: disturbance surface slope in the length of 20 meters,natural slope in the length of 20 meters,disturbance surface slope in the length of 40 meters,natural slope in the length of 40 meters,disturbance surface slope in the length of 60 meters,and natural slope in the length of 60 meters.Physical properties and soil water infiltration process in different treatments were measured,and four common infiltration models (Kostiakov model,Horton model,Philip model,and general empirical formula model) were used to fit soil water infiltration process.The relationships between physical and chemical properties with soil water infiltration characteristics (initial infiltration rate,average infiltration rate,steady infiltration rate,and 90min cumulative infiltration) were also analyzed.【Result】In same treatments,longer slope length had smaller soil bulk density.With surface disturbance and natural slope,the differences in total porosity and non capillary porosity were not significant,and initial soil water content was in the order of 60>40>20 meters.The fitting accuracy of Kostiakov model was 0.646-0.963 with an average of 0.886,that of Horton model was 0.878-0.981 with an average of 0.953,that of Philip model was 0.317-0.709 with an average of 0.592,and that of the general empirical formula model was 0.765-0.970 with an average of 0.920.Horton model had the largest fitting accuracy. Under different slope lengths,soil water infiltration of natural slope was greater than disturbed surface.Correlation analysis showed that soil water infiltration capacity was negatively and significantly correlated with soil bulk density,positively correlated with non capillary porosity,and significantly and positively correlated with soil ventilation.【Conclusion】With 20 meters slope length,surface disturbance was not conducive to improve soil permeability,while with 60 meters slope length,soil ventilation and water permeability were better.Horton model was the optimal model to analyze and predict soil infiltration. |
| Key words: disturbed surface slope length soil physical properties water infiltration |
