滇西北剑湖双河水库流域不同土地利用类型下土壤理化性质及其对抗剪性能的影响
Soil Physical and Chemical Properties of Different Land Use Types and Its Influence on Shear Resistance in Jianhu Watershed of Northwestern Yunnan
[目的]通过对滇西北剑湖双河水库流域不同土地利用类型下的土壤理化性质和抗剪性能关系的研究,为研究区域及同类型的水土流失地区治理提供一定的依据和思路。[方法]以云南省大理州剑川县双河水库流域为研究区域,将研究区草地、林地、耕地和采矿用地 4种土地利用类型的土壤作为研究对象,根据当地干湿季节的土壤含水率,配置了三种实验含水率,分别对应旱季含水率 15%,雨季含水率 35%,和过渡季节的含水率 25%,并测定土样的理化性质和抗剪性能,分析不同土地利用类型的理化性质及抗剪性能的差异,并分析土壤理化性质对抗剪性能的影响。[结果]结果表明:(1)在 10种实验选定的土壤理化性质指标中,有 7种指标(分别是pH、TP、TN、TOC、氮磷比、粉粒和砂粒)在不同土地利用类型土壤中存在显著性差异,并且差异主要存在于采矿用地、耕地和其他类型的土壤中。(2)4种土地利用类型的抗剪强度均随着土壤含水率的增加而减小,随着垂直压力的增加而增加;粘聚力和内摩擦角随着含水率增大基本呈减小趋势。(3)土壤理化性质和抗剪性能的相关性分析表明,在 15%含水率下pH、粉粒、砂粒与抗剪强度具有显著相关性;在 25%和 25%含水率下,pH与粘聚力、内摩擦角具有显著相关性。[结论](1)人为扰动会对土壤理化性质造成一定的影响。(2)土壤粒径、含水率、pH等是与土壤抗剪性能密切相关的理化性质,其中土壤粒径和含水率对抗剪性能的影响是直接的,而pH会通过影响土壤生物和微生物的生长和生活环境,从而间接影响土壤的抗剪性能。(3)在 15%含水率下,黏粒和砂粒含量对抗剪性能有显著影响,而在 25%和 35%含水率条件下该影响逐渐减弱,说明研究区域在干旱条件下,土壤的物理性能对抗剪性能会产生影响,含水率增大后,该影响减弱。
[Objective]Through the study of the relationship between soil physical and chemical properties and shear resistance under different land types,it provides certain basis and ideas for the control of soil and Moisture loss in study area and the management of the similar soil erosion area.[Method]Taking the Jianhu Moistureshed in Jianchuan County,Dali Prefecture,Yunnan Province as a typical study area,the four types of soils in the study area which are grassland,woodland,cultivated land and mining land were used as the research object.According to the local soil moisture content in the dry and wet seasons,three moisture content were configured respectively.Corresponding to 15%moisture content in the dry season,35%moisture content in the rainy season,and 25%moisture content in the transition season.Soil physical and chemical properties and shear strength were tested in the laboratory.[Results]The results show that 1)7 out of 10 index of soil physical and chemical properties(they are pH,TP,TN,TOC,nitrogen to phosphorus ratio,silt and sand,respectively)have significant differences among the four types of soil,and the differences mainly exist between mining land,cultivated land and other types of land;2)the shear strengths of the four land use types decrease with the increasement of soil moisture content,while increase with the increasement of vertical pressure;the cohesion force and internal friction angle basically decrease while moisture content increasing;3)the correlation between physical and chemical properties and shear strength shows the at 15%moisture content,pH,Silt,and sand are significantly correlated with shear strength;when moisture content increasing,pH is significantly related to cohesion and internal friction angle.[Conclusion]1)It is proved that external disturbance will have a certain impact on soil physical and chemical properties.2)According to the correlation analysis of physical and chemical properties,soil particle size,moisture content,pH are the properties closely related to soil shear resistance.Among them,soil particle size and moisture content are directly affect soil shear property,while soil pH can indirectly affect the soil by affecting the growth and living environment of soil organisms and microorganisms.3)At 15%moisture content,the content of clay and sand has a significant impact on the shear strength,while under the conditions of 25%and 35%moisture content,the effect gradually weakens,indicating that under drought conditions,soil physical properties will have an impact on the soil shear resistance,and the impact will be weakened when moisture content increases.
王金蕾;陈晨;杨苑君;
云南农业大学 水利学院 云南昆明 650021;西南林业大学 生态与环境学院 云南 昆明 6650224;云南农业大学 水利学院 云南昆明 650021;
Soil shear resistance soil physical and chemical properties land use type
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