摘要
辽西北地处干旱半干旱地区,降水量少而蒸发量大,容易导致土地沙化,产生水土流失和生态环境问题,制约当地社会经济和生态文明建设的可持续发展。[目的]本文分析不同沙化程度草地土壤饱和导水率特征及影响因素,揭示土地沙化过程中土壤水分入渗动态变化机制。[方法]以辽西北沙化草地为研究对象,基于室内环刀法、现场采样和室内分析相结合的方法,揭示4种不同沙化程度草地的土壤饱和导水率及影响因素。[结果]不同沙化程度草地土壤饱和导水率表现为未沙化(2.46 mm/min)<轻度沙化(5.57 mm/min)<中度沙化(8.72 mm/min)<重度沙化(9.04 mm/min),未沙化草地各土层土壤饱和导水率仅为重度沙化草地各深度土壤饱和导水率的27.21%;不同沙化程度草地饱和导水率随土层深度变化整体表现为增大的趋势。深度为0~30 cm土壤饱和导水率随沙化程度的加剧而增大,未沙化草地表层土壤饱和导水率仅为重度沙化草地的17%左右;深度为30~70 cm土壤饱和导水率同样表现为未沙化<轻度沙化<中度沙化<重度沙化,其中未沙化草地饱和导水率为重度沙化草地的30%左右;深层为70~100 cm土壤饱和导水率同样表现为未沙化<轻度沙化<重度沙化<中度沙化,其中未沙化草地饱和导水率为中度沙化草地的40%左右;磷酸酶与饱和导水率呈显著负相关关系,砂粒、体积质量、非毛管孔隙度与饱和导水率呈显著正相关关系;饱和导水率可以一定程度上代表其他指标变化规律,且与沙化程度呈线性关系,可解释98.70%的数据。[结论]辽西北沙化草地土壤饱和导水率表现为随着沙化程度的加重而升高;不同沙化程度草地土壤饱和导水率随土层深度增加整体表现为增大的趋势;植被恢复降低了土壤饱和导水率;沙化程度越高,土壤砂粒量、体积质量和非毛管孔隙度越高,土壤养分量、酶活性、粉黏粒量和毛管孔隙度随沙化程度增加而降低,植被通过增加土壤养分量和生物活性改变了土壤孔隙组成,增加了土壤持水能力,降低了土壤饱和导水率;砂粒、磷酸酶、体积质量、非毛管孔隙度为影响饱和导水率的主要因子;饱和导水率与沙化程度呈线性正相关关系,可作为评价辽西北草地沙化程度的指标。
【Background and Objective】The arid and semi-arid regions in Northwest Liaoning Province are characterized by low precipitation and high evaporation,leading to desertification,soil erosion and degradation.This paper presents the results of an experimental study on variation and determinants of saturated hydraulic conductivity of soils in these regions.【Method】This study was conducted in grasslands exhibiting various levels of desertification.We measured the saturated hydraulic conductivity of soils at different depths,along with various influencing factors across different regions.【Result】The impact of desertification on soil hydraulic conductivity varied with soil depth.In the top 0-30 cm soil,the saturated hydraulic conductivity of soil in non-deserted,slightly deserted,moderately deserted,and severely deserted regions was 2.46 mm/min,5.57 mm/min,8.72 mm/min and 9.04 mm/min,respectively.The impact of desertification on hydraulic conductivity of soil in the 30-70 cm layer is similar,with the saturated soil hydraulic conductivity in the non-deserted regions being 30%of that in the severely deserted region.In the 70-100 cm layer,the saturated soil hydraulic conductivity in different regions was ranked in the order of non-deserted<slightly deserted<severely deserted<moderately deserted,with the saturated soil hydraulic conductivity in the non-deserted region being 40% of that in the moderately deserted region.Saturated soil hydraulic conductivity was negatively correlated with soil phosphatase and positively correlated with sand content,bulk density,and porosity of non-capillary pores.Soil saturated hydraulic conductivity linearly decreases with soil desertification in y=13.13x-31.80,which could explain 98.70% of the variation in the hydraulic conductivity.It was also found that,regardless of the level of desertification,soil hydraulic conductivity tended to increase with soil depth and vegetation coverage.【Conclusions】The saturated hydraulic conductivity of soils in the grasslands in the northern Liaoning Province varies with both soil depth and the degree of desertification.Key factors influencing this variation include sand content,phosphatase content,bulk soil density,and presence of large non-capillary pores.
作者
蒋蒙蒙
罗根华
吕刚
冯梦隆
JIANG Mengmeng;LUO Genhua;LYU Gang;FENG Mengong(School of Environmental Science and Engineering,Liaoning Technical University,Fuxin 123000,China)
出处
《灌溉排水学报》
CAS
CSCD
2024年第10期46-54,共9页
Journal of Irrigation and Drainage
基金
辽宁省教育厅基本科研项目(LJ212410147029)。
关键词
辽西北
土壤入渗性能
沙化程度
饱和导水率
Northwest Liaoning
soil infiltration performance
desertification degree
saturated water conductivity
作者简介
蒋蒙蒙(1994-),女,黑龙江绥化人。研究生,研究方向为水土保持与生态修复。E-mail:1543122725@qq.com;通信作者:吕刚(1979-),男,吉林九台人。教授,博士生导师,主要从事水土保持与荒漠化防治的教学与科研工作。E-mail:lvgang2637@126.com。
