东北黑土区冻融作用与土壤水分的关系

地球上受冻融作用的面积约占全球陆地总面积的70％，在我国，受冻融作用的面积约占国土陆地总面积的98％。冻融作用对土壤水分、密度、有机质和土壤的机械组成等因素都有不同程度的影响。在东北典型黑土区，通过野外观测和室内试验，研究冻融作用与土壤水分的关系。结果表明：冻融作用使土壤水分由土水势高的下部向土水势低的上部迁移，增加了土壤冻结层的含水量；土壤水分迁移使得下部未冻结层的土壤含水量降低，其降低程度受下部土壤含水量和浅层地下水埋深的影响；冻结过程中土壤水分迁移导致土壤膨胀变形，而土壤的膨胀变形是发生土壤冻融侵蚀的主要因素。研究结果可为东北黑土区冻融侵蚀防治和农业可持续发展提供理论依据。

Relationship between freeze-thaw action and soil moisture for Northeast black soil region of China

It is about 70 percent of the whole land area on earth that effected by freezethaw action,but it is 98 percent in China.Freeze-thaw action can effect in varying degrees to factors such as soil moisture,density,organic quality and soil machinery composition.Based on field observation and interior experiment,the relation between freeze-thaw action and soil moisture was studied in Northesat black soil region.Results showed that under the freeze-thaw the soil water flow from lower part with height flow to upper...