Three-dimensional Visualization System Design Of Soil Salinity In Southern Xinjiang

Soil salinization will hinder the normal growth of crops and restrict the sustainable development of agriculture.Therefore,the study of soil salinization information is of great significance for farmland salinization control.Due to the inefficiency and unintuitive shortcomings of traditional data sampling and visualization methods,the use of computer technology to visualize soil salinity information in 3D,and then obtain the spatial variation information of soil salinity,has become a hot and difficult research at home and abroad.In the related research on soil salinity,that the conductivity is proportional to the salinity,and the conductivity can be used to reflect the salinity in the soil.In this paper,the farmland in southern Xinjiang was selected as the experimental area,and the EM38-MK2 earth conductivity meter was used to quickly collect the apparent conductivity of the soil,and to detect the measured conductivity of the soil samples.Through the use of linear models,kriging interpolation,Cesium 3D visualization and other methods,research work such as soil sampling,accurate interpretation of conductivity,conductivity interpolation calculation,spatial variation analysis of soil salinity,and realization of a 3D visualization system for soil salinity research.The main findings include the following aspects:(1)Research on Inversion Model of Soil Conductivity Based on Electromagnetic Induction DataThe EC_h0.5,EC_h1.0,EC_v0.5,and EC_v1.0 collected by the EM38-MK2 in the horizontal and vertical modes were used for correlation analysis to ensure the reliability of the data.Conductivity analysis.The four data were modeled according to the soil layers of 0?20cm,20?40cm,40?60cm,60?80cm,and 80?100cm,and the modeling factors were determined.Then,based on the apparent conductivity data and the measured soil conductivity data,the soil sample data group is divided into a modeling set and a validation set in a ratio of2:1 for modeling,and the soil conductivity interpretation model is obtained.Model metrics using the best modeling factors.The research results show that the correlation coefficients of the apparent conductivity data are all greater than 0.95,which is reliable,and the moisture content of the soil samples is about 20%,which meets the model establishment conditions.For soil layers with depths of 0?20cm and 20?40cm,EC_h0.5 was used as the modeling factor,and the coefficients of determination(R²)were 0.81 and 0.85,respectively;in the 40?60cm soil layer,EC_v0.5 was used as the modeling factor,and R² was 0.91;in 60?80cm,80?100cm soil layers,using EC_v1.0 as the modeling factor,R² is 0.84,0.74,respectively.The RPD index of the soil conductivity interpretation model is all greater than 2.0,which has a good predictive ability.(2)Three-dimensional variability of soil salinityCalculate the conductivity through the soil conductivity interpretation model to obtain the soil conductivity data of each soil layer,realize the 3D visualization of soil salinity by using the ordinary 3D-Ordinary Kriging method,and study the southern Xinjiang.Distribution of salinity in farmland soil profiles.The research shows that the ordinary three-dimensional kriging interpolation method can be used to display the distribution position and content of salt in the soil profile with high precision.Under the influence of,the main distribution of salinity is the soil layer of 0?20cm.With the deepening of the soil layer,the soil salinity content gradually decreased.In some areas,the salinity content of the 20?40cm and 40?60cm soils is similar.Preliminary analysis is that drip irrigation leaches surface salt into this soil layer.(3)Research on 3D Visualization SystemConduct research and analysis on WebGL,conduct in-depth research on the open source WebGIS platform Cesium,and summarize the key features of Cesium.Through the demand analysis of the three-dimensional visualization of soil salinity,the system function modules are designed,and the system design principles and the three-layer architecture design of the presentation layer,the service layer and the data layer are determined.Make certain modifications to the Cesium source code to meet the needs of soil conductivity data displayed in the underground perspective.Developed a three-dimensional visualization system of soil salinity,and use soil conductivity scatter data,overall interpolation map,section interpolation map and other data in the system to realize the viewing and visualization of related soil conductivity attribute values from above-ground and underground perspectives.