Study On The Rhythm Of Water And Soil Saltion Transference In Songnen Plain

This paper takes Shisan lake in Changling district Jilin Province as an example,choosing representative periods to reserve on the spot,conduct corresponding tests andanalyze by contrasting. Then the author analyze the thermodynamics structure and theinfluence in the feature of transference of soil water and salt element of the alkalization ofSongnen plain in the precipitation period,drought period,frozen period and thawing periodrespectively. It shows that alkalization soil in frozen season in research region holds the thermalstructure as following: the frozen layer-frozen and transition layer-unfrozen layer; howeverthe in thawing season the thermodynamics structure is that thawing layer-thawing andtransition layer-frozen layer- frozen and transition layer-unfrozen layer; the thermodynamicsstructure in the precipitation period and drought period of soil ion are quilt simple that thefrozen layer fade away, and the soil temperature grad relieves gradually. The temperaturegrad and the soil water grad consist of the drive of the accumulation of soil water and salt ionfor alkalization soil in winter. The soil salt ion from the frozen layer in winter has been accumulating in the soilsurface. In frozen season, the temperature grad and the soil water grad are formed when thetemperature fall down to the melting point and abstract soil water upward to the surfacethrough the soil capillary. As the grads become severe, the soil water is transported to thetransition layer. At the interface of the frozen layer, solid and liquid water are mixed together,which bring about sharp water grad. The grad simulates the pumping effect to develop furtherand form the mechanism of the accumulation effect. The capillary water proves to be themain carrier of soil salt ion. As the soil water enrich in the frozen belt, the soil salt ionaccumulates in the frozen layer. In thawing period, the frozen layer dwindles from both the upper and the deep transitionlayer. The solid crystal formed in winter take phase change part of liquid water transporteddown by gravity to upper transition layer to form the solution enrichment. Above the belt, theevaporation becomes stronger as the forthcoming of spring, and the soil salt ion accumulatesin the thawed layer. The soil water in the deep unfrozen soil layer has been transferring sill tothe deep transition layer, and taking phase change. The underground water participatesdirectly the outside water influence only when the transition layer vanish thoroughly. Thethermodynamics mechanism of the transfer of soil water is the important part of thegeographical mechanism of soil alkalization in Songnen plain. In precipitation period and drought period, the transfer of soil ion is caused by gravitypotential and matrix potential, influenced by the precipitation and evaporation as well. The change of soil section is considered mainly from the aspects of water and heat inthis paper, which is quite important for the research of the change of water and soil salt ionfor seasonal frozen earth areas. The one should be emphasized is that the main restrict factorof the transfer of soil water and salt ion is the thermodynamics structure of soil. The rhythm of water and soil salt ion transference will provide ecological significance tothe study alkalization wetland and grassland in Songnen plain. People can take correspondingmeasures to promote the soil development according to rhythm of water and soil salt iontransference.