Evaporation Test And Model Study Of Saline-alkaline Soil

This paper combines the two hotspots of the world,the soil salinization and the soil evaporation model,to explore the soil evaporation mechanism of saline-alkaline soil to achieve the purpose of quantifying the influence of soil salinity on soil evaporation.In this paper,the mechanism of soil salinity affecting soil evaporation,soil moisture transport,soil temperature and soil conductivity is studied by means of outdoor soil column test,theoretical basis analysis and model correction.A modified model describing the evaporation of saline-alkaline soil was carried out,and the model parameters were determined based on the experimental data.The main research results are as follows:(1)The influence of meteorological factors on soil evaporation is interactive and restrictive.By analyzing the correlation between single meteorological factors and soil evaporation and combining with the characteristics of soil evaporation,the order of correlation is: solar radiation > atmospheric temperature > wind speed > relative humidity > atmospheric pressure.When the influence of soil factors is amplified,the correlation of meteorological factors will be weakened.Meteorological factors are only one factor affecting soil evaporation,while soil conditions are another important factor;(2)The evaporation of saline-alkali soil is different from the soil that is not affected by salinization.The soil salinity will affect soil evaporation and change soil properties.In the second stage of soil evaporation,the amount of soil evaporation decreases with the increase of soil salinity,but in the case of winter frozen soil,the soil salinity will increase the cumulative evaporation of the soil,and when the soil The surface of the surface will inhibit soil evaporation due to salt accumulation.The soil temperature increases with the increase of soil salinity.Soil salinity will increase soil water retention and change the distribution of soil water content.feature;(3)A soil evaporation model of saline-alkali soil was established to quantify the effect of soil salinity on soil evaporation,and the parameters of the model were determined by experimental data.The rationality,reliability and accuracy of the model were verified by various fitting tests.At the same time,the accuracy of the model was higher than that of the original model.For different five processing,the calculation accuracy is increased by 35%,43%,50%,57% and 69%,respectively.At the same time,the model has strong theoretical basis,fewer parameters needed and wider applicability,so it is easy to popularize and use.