冻融循环对黄土区土壤饱和导水率影响的试验研究  

Study on the Effect of Freeze-thaw Cycles on Saturated Soil Hydraulic Conductivity in Loess Area

作　　者：赵春雷[1,2] 邵明安[3,2] 贾小旭[3] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [3]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100101

出　　处：《土壤通报》2015年第1期68-73,共6页Chinese Journal of Soil Science

基　　金：国家自然科学基金项目(41390461;51179180)资助

摘　　要：为探明黄土高原北部冻融过程对土壤饱和导水率的影响,采用冻融循环模拟的方法,分析了不同土地利用和不同土层深度下冻融循环前后土壤饱和导水率(Ks)的变化特征。结果表明:冻融过程对Ks有显著影响,经15次冻融循环后,Ks总体上呈减小趋势,其影响程度因土地利用类型和土层深度不同而异。冻融循环后4种土地利用0~10 cm土层Ks均显著下降,柠条林地下降幅度最大,其次为农地、苜蓿地和撂荒地,这与土壤的松散程度有关。除撂荒地外,冻融循环过程对其它3种土地利用10~20和20~40 cm土层Ks无显著影响。4种土地利用0~10 cm土壤田间持水量和饱和含水量经冻融循环后均有不同程度下降,表明冻融循环后土壤孔隙度降低度降低。研究可为揭示冻融循环对黄土区土壤饱和导水率的影响机理以及为土壤水分匮乏的寒区旱区春季降水及积雪融水的高效利用提供理论依据。To clarify the effects of freeze-thaw cycles on saturated soil hydraulic conductivity(Ks) in the northern Loess Plateau, the variation characteristics of Ks at different soil depths before and after freeze-thaw cycles under the different land uses were determined using the method of the freeze-thaw cycles simulation. Results showed that the freeze-thaw cycles had significant effects on Ks. The values of Ks generally decreased after 15 freeze-thaw cycles, and the degree of the decrease varied with different land uses and soil depth. Ks at the soil depth of 0- 10 cm significantly decreased under the four land uses, and the degree of the decrease in Ks was the highest under Caragana korshinskii land, followed by cropland, alfalfa land, and fallow land, which may be related to the soil density. Except for fallow land, freeze-thaw cycles had no obvious effect on Ks under the other three land uses at the soil depths of 10- 20 and 20- 40 cm. The field capacity and saturated soil water content at the depth of 0- 10 cm decreased under the four land uses after freeze-thaw cycles, suggesting a reduction in soil porosity. The results could provide theoretical basis for the reveal of response mechanisms of Ks to freeze-thaw cycles, and for the efficient use of spring rains and snow water sources in cold and arid regions.

关 键 词：冻融循环 饱和导水率 入渗 土地利用 黄土区 

分 类 号：S152.7[农业科学—土壤学]