Why do many regions in China have the problem of land salinization, and why are many people not very familiar with this situation? What are the widespread causes of land salinization? Today, the editor of Baidu Security Network will give you a detailed explanation.

The factors affecting soil salinization are many, including natural factors and human errors. Natural factors include climate, geology, topography, hydrology and geology; human errors mainly manifest as human activities of renewing and transforming nature and integrating with nature. Among them, the climate factor is the fundamental factor causing soil salinization. Without obvious volatilization, the soil surface is not easy to accumulate salt明显。

Climate

The climate of the reclamation area belongs to a continental climate with extreme drought caused by temperate climate, characterized by abundant sunshine, diverse heat sources, scarce drought rainfall, large annual rainfall, significant temperature differences between day and night, and long days of thunderstorms. Such climatic conditions have a great impact on soil formation. Scarcity of drought rainfall leads to a sparse plant community on the surface, poor accumulation of microorganisms, and a very weak leaching action in the soil layer, with a clear reaction of lime powder in the soil layer. Therefore, the organic matter content in most natural and cultivated soils in the area is not high. The larger the annual rainfall, the greater the total area of saline soil and soil salinization in the area.

Water usage

Groundwater: There are about 16 large water bodies in our area, and the key water bodies affecting the reclamation area are the Aksu River water body, the Ertix River water body, and the Tielan River water body. The melting water of the mountains’ ice and snow is the most important water resource. There are 1293 glaciers in our area, with a total area of 4098 square kilometers, and an estimated storage capacity of about 21.54 million cubic meters, with an estimated annual runoff of 1.367 million cubic meters. The operation direction and metabolism direction of surface water in the war zone are all from north to south. This water absorbs the artesian water and some natural recycled water in the mountainous area along the way. Because there are more salt-rich soil layers at the foot of the Tianshan Mountains, when the rivers flow through the salt-rich soil layers, the easily soluble salts in the soil are dissolved into the water, increasing the mineralization of the water. When the surface water flows to the end of the fan, because it absorbs a large amount of recycled water and obvious volatile functions, it extracts the surface water, which is also the process of migration of surface water mineralization. Because of the transfer and accumulation of salt, as well as the unsmooth drainage pipelines, a large amount of salt accumulates in the surface water. This water is both the driving force for salt transport and the key water resource for the replenishment of local surface water, which is the cause of the high salinity water in the area. The mineralization of surface water in the area is generally between 5-15g/l, and the pH value is between 7 and 8, which is weakly alkaline brackish water and edible salt water and cannot be used for irrigation. The area where the surface water mineralization exceeds 10 grams per liter is high-mineralized salt water and cannot be used for drinking or irrigation, accounting for 94.29% of the total area.

Surface water: According to the data of this soil survey, the shallow surface water of each irrigation project has several characteristics such as shallow burial, high mineralization, and its operation direction and metabolism direction are all from north to south. The burial depth of surface water is between 1.0 and 3.0 meters, and their total area accounts for 94.64% of the total area. Only in the northern part of the four teams, five teams, and six teams, and on both sides of the rivers and straits, there are water belts in the whole first agricultural division. Under the condition of extreme drought, the shallow and highly mineralized surface water is the key source of soil salt in the reclamation area, and it is also the most important reason for the large total area of salt soil and salinized soil in the reclamation area.

Human activity impact

The comprehensive effects of natural factors such as climate, hydrology and water conservancy, landform, soil layer and rock stratum, and geological structure in the project area are the basic factors for the occurrence and development trend of soil salinization. The influence of human activities is the standard for its evolution and development trend in a certain direction. At present, a part of farmland in the irrigation project still uses the method of flood irrigation, with a large flow of irrigation water. The distribution channels and farmland ditches in the region are all earthen channels, with serious leakage. Therefore, a lot of water in the channel fields infiltrates into the shallow deep groundwater, and part of the surface water infiltrated into the fields and converted into groundwater is metabolized in the drainage channels. The collapse and sedimentation of the drainage channels are serious, the drainage pipelines are not smooth, and other volatile functions are metabolized. The minerals in the water stay in the surface soil, leading to the intensification of soil salinization levels.