Study On Soil Salinization Characteristics And Ecological Restoration Technology Of Daihai Lakeside

The ecological environment of inland lakes in semi-arid areas is fragile and sensitive.Due to global warming and unreasonable human reclamation,the ecosystem of lakeside belts is degraded,threatening the ecological health of lake water.Daihai is a typical inland lake on the Mongolian-Xinjiang Plateau.In recent years,it has faced problems such as falling water level,increasing salinity,salinization of the lakeside zone,and deterioration of water quality.It is urgent to carry out research on the soil characteristics and remediation technology of the lakeside zone.This study investigated the current status of the soil environment in the Daihai lakeside belt,studied the distribution characteristics of the surface soil and profile soil salinization in the lakeside belt,calculated the total amount of salt in the watershed,identified important areas and important periods of salt reduction and enrichment in the lakeside belt,and developed the lakeside belt.In this paper,based on the investigation of the current situation of Daihai research,soil samples were taken from the lakeside belt in May and September2021 to study the distribution characteristics of the surface soil and profile soil salinization in the lakeside belt.By calculating the total salt in the basin,it is verified that the lakeside zone is an important area for salt reduction and enrichment in the region.According to the research results and watershed overview,the analytic hierarchy process is used to screen the ecological restoration technology suitable for the Daihai lakeside belt.The restoration technology research is carried out according to the local conditions,and it will provide important technical reference for the improvement of the water quality of the Daihai Sea and the ecological restoration of the inland lakes in the Mongolia-Xinjiang Plateau.The main results and conclusions of the paper are as follows:（1）There were obvious seasonal and regional differences in the surface soil salinity in the Daihai lakeside.On the whole,the lakeside area near the lake had the highest salinity,and the dominant salt ions were Na⁺and Cl^-.In terms of time,the average salinity in May was higher than that in September.The total salinity on the north side near the lake in May was the highest at 56.09 g/kg,and the highest on the west side near the lake in September was 25.40 g/kg.The maximum values of p H and alkalinity were located on the south side of the lake area,which were 9.38 and 64.50%,respectively.（2）Through the research on the salinization characteristics of different types of soil profiles in the Daihai Sea,the results showed that the soil salinity in the grassland and shoal was surface aggregation.The average total salt content in the surface layer were 1.99 and 15.27 g/kg,respectively.The total salt content at 10-20 cm of saline-alkali land is up to 17.30 g/kg.Both the saline-alkali land and the shoal soil were the alkaline soil,while the grassland surface mostly was the moderately alkaline soil,and the alkalinity degree decreased along the soil depth.（3）With the shrinking of the lake surface area,the salinity content in the lakeside zone showed an increasing trend,among which the total salt content of the vegetation increased and the total salt content of the lake water body decreased.It can be concluded that the lakeside zone was a sensitive area for salt reduction and enrichment in the region,which can slow down the continuous increase of salt in the lake.（4）The soil alkaline-hydrolyzed nitrogen and organic matter are generally deficient in the Daihai lakeside,and the available phosphorus and available potassium are extremely abundant,showing a decreasing trend with the increase of depth.The shoal soil had the highest nutrient content,which was related to its geographical location and vegetation coverage.The main factors of total salinity were Mg²⁺,Cl^-,Na⁺,SO₄^2-,and the main factors of alkalization in the study area were p H,CO₃^2-,HCO₃^-.（5）The applicability of the ecological restoration technology of the lakeside belt was studied by the AHP,and the proposed plan for the restoration of the Daihai lakeside belt was put forward,which mainly included:（1）Restoration of basement（2）In situ ecological restoration of vegetation（3）Cleaning of halophyte residues in the lakeside belt（4）Zone Time-sharing lakeside belt management.