Study Of Soil Salinization In Yellow River Flood Plain

Soil salinization has become a global environmental issue that mankind is facing. Our country pays more and more attention to the impact of salinization on the agricultural economy, environment and ecosystems. Due to the soil structure, salinization occurs in the Yellow River plain at different degrees. Qihe County, Dezhou, Shandong Province is selected for the study area in the field survey. Based on field measurements, the use of SPSS statistical analysis software is adopted to study the dynamic process of groundwater sampling points. The ERDAS software is utilized to abstract the related information about saline-alkalized soil. The3S technical analysis is used to study local groundwater depth, vertical distance of the Yellow River and the variation of salinity in the study area. It is also assistant to find out the sources, destination, change rate and arising reasons of saline-alkalized soil. By revealing the depth of groundwater salinity changes on the impact of soil to control soil salinization in the area, it is expected to prevent its further spread and land degradation, maintain agricultural sustained, steady development, provide theory and data support. Specific conclusions are as follows:(1) From2007to2011, the average depth of groundwater sampling data indicate that: Qihe County has a generally shallow groundwater table (base throughout the depth<4m), less volatile annual change. Horizontal comparison of the typically buried underground at Xigao Village and Dalinguo Village in January shows that the groundwater level gradually increases from March, then decreases to the lowest level in September, then begin to rise, shows a typical agricultural water drawdown curve. By mapping with ArcGIS software, groundwater studies for the spatial variation shows that:the most shallow depth along the Yellow River, southwest of depth deeper Qihe County.2007and2011Table Change analysis:the overall performance of the area variance in the east-west direction is larger than that in the north-south direction. The variations of groundwater depth are more than1.5m in both Yancheng Town and Xuanzhangtun Town.(2) By analysis and comparison of spatial distribution and salinity distribution of groundwater table in Qihe County, we can see that salinization distribution is serious in the range of groundwater from2.1m to2.7m, and the most serious salinized soil occur at the depth from2.2m to2.5m, but the proportion of salinized land area is relatively small salinization when the groundwater depth occur from2.7m to3.4m. Linked to the shallow groundwater at Qihe County as an example, groundwater transpiration is strong, even in the case of low salinity groundwater, due to shallow ground water, ground water evaporate into the soil much more water, which will carry much more salt, and make the salt accumulating in the soil. Therefore, the relation of groundwater depth and salinity can be obtained. The more shallow groundwater areas, more severe soil salinization. The deeper the groundwater table, the smaller proportion of soil salinization.(3) Calculate coordinates of sampling points with ArcGIS, we obtain the vertical distance of sampling points from the Yellow River. Comparing the groundwater level data in2011, and doing regression analysis with SPSS software, we find there exists a general linear law between the vertical distance from the Yellow River and soil salinization. The smaller vertical distance of sampling points from the Yellow River, the more serious salinization; vice versa larger vertical distance, the slighter salinization.Results show that the annual and seasonal differences are significant of the spatial-temporal distribution of salinzed land in the studied area. The county-wide underground water level is shallow and most of the areas around the buried depth of2m, fewer areas to an annual maximum depth of5m. Salinized land shares much distribution in relatively shallow buried areas or areas that suffer stronger changing volatility concerning buried depth. Buried depth is the main factor for the salinized land change in the area.