Research On The Inversion Of Land Salinization Based On Remote Sensing Technology And The Influence Of Groundwater On Land Salinization

The problem of soil salinization in southern Xinjiang has severely endangered and affected the local ecological environment and sustainable development of agriculture.Since the formation and prevention of soil salinization are the result of a combination of many factors,its harm and complexity are worthy of continuous in-depth attention and study by scholars.Therefore,this paper selects the 34th Regiment and the 35th Regiment of Xinjiang Second Division as the research area,using multiple linear regression model,Pearson correlation coefficient,multiple determination coefficient,adjusted multiple measurement coefficient,root mean square error,kriging Interpolation method,weighted overlap analysis method and other methods,based on remote sensing images,soil samples and groundwater sample data,reveal the spatial distribution characteristics of soil salinization in the area,and quantitatively analyze the influence of the two factors of groundwater depth and salinity on the intensity of soil salinization.Impact.It provides method reference and technical support for the monitoring of land salinization in the study area,and has certain guiding significance for the prevention and control of land salinization.The main results achieved are as follows:(1)Among the 45 soil samples,there are three types of non-alkaline soil,alkaline soil,and strong alkaline soil.The soil samples are relatively alkaline.The EC value varies greatly.There are four kinds of soil samples salinization phenomena in the samples:mild salinization,moderate salinization,severe salinization and non-salinization,and the salinization process of soil samples is quite different.The number of soil samples is mainly non-salinized soil,and individual soils have a greater degree of salinization.The average spectral broken lines of the seven salinization intensities generally have similar changing trends.But the reflectivity of different salinization types is different.(2)The correlation coefficient between pH value,EC value and resampling transformation is the logarithmic first-order differential((lgA)').On the basis of 0.01 level(two-tailed),the correlation coefficient between B4 and pH value and EC value is extreme.Strong correlation.In addition,there is collinearity between B4 and B5;there is no collinearity with other bands.The model fitting effect is good,the prediction accuracy of the model verification result is high,and the predicted value of the model will be lower than the measured value.(3)The multiple linear regression model is applied to the inversion of salinization intensity expressed by soil pH value and EC value obtained from OLI images.The pH and EC value image inversion accuracy verification results are good,and the image inversion accuracy is high.Alkaline soil area accounts for about 76.85%of the inversion area,strongly alkaline soil area accounts for about 12.31%of the inversion area,and non-alkaline soil area accounts for about 10.84%of the inversion area.In the study area,non-saline soil accounted for about 29.85%of the inverted area,slightly saline soil accounted for about 45.24%of the inverted area,moderately saline soil accounted for about 23.93%of the inverted area,and heavily saline soil accounted for about 23.93%of the inverted area.The inversion area is 0.98%.The classification of soil salinization risk levels includes four levels:non-salinization,mild salinization,moderate salinization,and severe salinization.Non-salinized land accounts for about 25.79%of the inversion area in the study area,lightly salinized land accounts for about 44.95%of the inverted area,moderately salinized land accounts for about 28.29%of the inverted area,and heavily salinized land accounts for about The inversion area is 0.97%.(4)The diving depth and salinity data are normally distributed,the Kriging interpolation groundwater burial range is 1.64-6.46m,and the groundwater salinity range is 2.72-27.25g/L.Severe salinization may occur at different depths and salinity.The buried depth of groundwater is 1.64-2m,and the degree of severe salinization of soil is the highest,and the probability of occurrence of severe salinization continues to decrease as the depth of groundwater increases.For the distribution of heavily saline-alkaline soil,the depth of groundwater has a greater impact on the degree of salinity of groundwater.The greater the burial depth,the less likely to be moderate salt-alkali.The depth of the water level continues to increase,and when the degree of salinity breaks through a certain critical value in the range of 22-24g/L,the degree of groundwater salinity has a greater impact than the depth of groundwater.With the increase in groundwater depth,the moderately salinized land has improved and turned into slightly salinized land.When a critical value is exceeded in the 5-5.5m interval,the overall saline-alkali soil is better improved.For lightly salinized and non-salinized land,the depth of groundwater relative to the degree of salinity of groundwater is the main factor.The soluble solid cations in groundwater samples are mainly Na+,and the anions are mainly Cl-.