Study On Saline Soil Water And Salinity Transportation Of Different Salt Recharge Types In Songnen Plain

The study on Saline-alkali soil in Songnen plain, not only have very important meaning in theory but also have more important meaning in applications. It will accelerate the research on the occurrence, formation, development, processes of ecological geochemistry, character mechanism and ecological geochemistry of landscape restoration on Saline-alkali Soil in Songnen-Plain, and also provide theoretical foundation for them.The article takes Saline-alkali Soil in Songnen plain as study object to reveal the formation mechanism, the development, the salt accumulation types and salinity transportation in different Saline-alkali Soil types in Songnen plain.The soil salt transportation in Songnen plain is influenced by topography, climate, terrain, geology, water character, parent matcrials and unreasonable human activities. Regional diversity of saline soil formation condition leads to different salt supply ways and has different water and salinity transportations.According to the salification conditions and relationships of saline-alkali soil in Songnen plain, we could get that the leading way of salt supply is different in different regions. Salt supply types of Songnen plain saline-alkali soil have three: Surface water salt supply type, Ground water salt supply type, Surface-ground water salt complex supply type.The main salt source of surface water salt supply come form surface water. It's environment is that the depth to groundwater is away below the critical value, the parents materials is relative viscosity, in low-lying land and the ground water cannot be drained away in time, which make saline-alkali soil well developed. This type soil mainly distributed in alluvial fan tableland close flow depression, lower groundwater table wind erosion depression under mound at the terrace plain and old lake basin depression and floodplain salinized soil development intact, salinized soil itself has taken shape in the area of the impermeable stratum. The process of soil water and salinity transportation can be recommended as: High ground surface runoff–contains water at low locations–surface water evaporation and salt eluvial on the surface ground. Temporal regularity is salification in dry seasons and desalinization in rainy seasons and stop in frozen seasons.Ground water salt supply type's environment is that in terrace plain the depth to groundwater is away relative shallow and abundant but surface water is short or drain in time. The water and salinity transportation takes evaporation discharge as characteristics. The process of water and salinity transportation can be recommended as below: ground water rise–evaporation–salt eluvial on the ground. This type mainly distributed in low location of terrace plain, which have well permeable parent matcrials and outflow river, for example Qianan, Tongyu, Changling and Qianguo. This type Saline-alkali can salification in all seasons except precipitation.Surface-ground water salt complex supply type is the most widespread one. The saline-alkali soil type in terrace plain and floodplain most belongs to Surface-ground water salt complex supply type, which can be affected by both small topography and river-net. The water and salt transportation of this type have dual characters of ground water salt supply type and surface-water salt supply type. This type mainly distributed in flood plain, terrace plain, low location of river-lake overbank and low plain of Songnen plain.