Research Of Soil Wind Erosion In Zhundong Areas Based On Wind Erosion Model

Soil wind erosion model is the frontier domains of soil wind erosion subject,It’s an effective method for quantitative study of soil wind erosion,It’s the important tool to soil and water conservation ecological benefits evaluation and wind erosion dynamic monitoring.This article selected east of Junggar Basin(Zhundong)as the study area,comparised the merits and faults of different models,analyzed suitability of models.Quantitative analysis by choosing two different models.Calculated the average amount of wind erosion in the study area by WEQ model,based on GIS technologies to analyzing the erosion grade.Using erosion model abroad to calculate the amount of different month soil wind erosion in 2016.To be specific,the principal achievements of this thesis are as follows:(1)To clarify wind erosion condition and impact factor,used field observation data and combined with meteorological data,the land use data,DEM,and remote sensing image to analyze the influence of soil wind erosion from 4 aspects: climate,soil,landform and vegetation coverage.using WEQ model in the study area with impact factors to evaluate and analyze the erosion grade based GIS technologies.The results showed that: In wind erosion force factors of climate,wind speed is the main factor.But the effect of wind erosion by climate conditions not only the wind factor,It’s the result of the combination of wind speed,precipitation,temperature and humidity.Influenced by various factors,the wind erosion classification was obvious in study area,and erosion intensity showed a trend of increase from south to north.The average erosion modulus was 4 470.64 t·km-2·a-1,with wind erosion amount reaching 99.695 3 million tons.Severe erosion was the main erosion degree,accounting for 43.02% of the area.It’s mainly Located in the central of study areas,where is belong to the Gobi desert,the vegetation coverage is extremely low,The topography is flat,sandy area is large,and wind erosion is severe.The proportion of is mired erosion and mild erosion less,accounting for 4.36% and 5.04% of the areas.They are mainly in the area of less soil erodibility and high vegetation coverage,and there are strong abilities to resist wind erosion.Moderate erosion occurs mainly in South of areas and central regions,accounting for 20.23% of the total areas.The regional land use type is natural grassland.Where the earth’s surface is uncovered,properties of soil is loose,the topography is flat is the main areas of deep erosion occurred.In order to verify the accuracy of the models,137 Cs trace method was used to comparatively analyze the model value.The verification results showed that the average relative error between 137 Cs tracer method and the model value was 7.78%,proving that the model in the study area had good applicability.(2)With different land-use type and meteorological data,as well as the data from field observation and investigation,by comparing with the wind erosion models all over the world,the author selected the model of wind tunnel experiments for the base model,and quantitatively calculated soil wind erosion modulus for all kinds of land-use type based on the actual condition of study area.The results of simulation showed that the soil wind erosion modulus have an obvious law: unutilized land(41.91% of the areas,wind erosion modulus6456.17t·km-2·a-1)>grassland(53.225.04% of the areas,wind erosion modulus3437.32t·km-2·a-1)>cultivated land(4.23% of the areas,wind erosion modulus758.71t·km-2·a-1).Soil wind erosion occurs mainly in April and May,accounting for52% of the annual amount of wind erosion.The occurrence of wind erosion concentrated in the specific month,and the wind erosion amount is large.The average erosion modulus was 4571.43 t/(km2·a),with wind erosion amount reaching101.94 million tons.April is the most intense period when the wind erosion occurred,because of the wind fast speed and high frequency as well as low vegetation coverage in this time.July and August is the time corps matured,and Vegetation was thriving,It’s the largest vegetation coverage,rainy weather period,and It’s also the period that the most weak wind erosion occurs.Soil wind erosion current situation of ZhunDong is the result of the combination of wind,Vegetation coverage,and Soil.The wind fastspeed and high frequency is the most important reason for strong wind erosion activities.Influenced by various factors,the wind erosion situation is more serious in study area.In order to verify the accuracy of the models,this simulation results were compared with the same period results of validation.The final conclusion is that system operation precision can reach more than 84%,proving that the model in the study area had good applicability,and it also can generally meeting the demand of regional soil erosion monitoring.