Spatial Variation And Influencing Factors Of Surface Evapotranspiration In Xiliaohe Plain

The water cycle maintains the energy balance in the natural environment and has an irreplaceable effect on the ecological environment.The surface evapotranspiration is an important part of the water cycle.The Xiliaohe Plain has a gentle terrain,a changeable climate,and relatively sufficient water resources,but it is not fully utilized.At the same time,the variation of surface evapotranspiration is unstable,which has an adverse impact on the production and life of local residents.In order to understand the variation characteristics and influencing factors of surface evapotranspiration in the Xiliaohe Plain,this paper selects the Xiliaohe Plain as the study area,and uses the surface evapotranspiration data of the study area from 2000 to 2019 to analyze the distribution characteristics and changing trends of surface evapotranspiration to study the influence of evapotranspiration.The factors of change are combined with the partial least squares model and the geographically weighted regression model to analyze the driving force of the surface evapotranspiration,and the relationship between the various influencing factors and the surface evapotranspiration is obtained,which provides a corresponding basis for improving the overall environment of the Xiliaohe Plain.The following conclusions were reached:1.Between 2000 and 2019,the Xiliaohe Plain in overall surface evaporation is on the rise,the range of 20 years the average evaporation between 183.5 ? 745.5 mm,and the general surface evaporation on the space distribution state of east west high low,in addition to the parts to reduce the tendency to the southeast,Xiliaohe Plain surface evaporation were both increased as a whole.2.Select five influencing factors of elevation,temperature,precipitation,population density and land use type,and analyze the correlation between each factor and surface evapotranspiration.In the elevation range of 150?300m,the surface evapotranspiration is relatively large.As the elevation increases,the surface evapotranspiration decreases and the rate of change decreases;temperature and surface evapotranspiration are obviously positively correlated in the northwest and middle of the plain;while precipitation Except for a small area in the southeast of the study area,it is highly correlated with surface evapotranspiration;the population density ranges from 100 to 5000 persons/km2,accounting for 6.89% of the total area,and the average evapotranspiration range is as high as 376.90 to 379.30 mm;in various lands Among the utilization types,the average evapotranspiration value of wetland is the largest,as high as 429.3mm,and the average evapotranspiration value of the paddy field is the highest in the wetland type,which is 447.2mm.3.Partial least squares method and geographically weighted regression model were used to analyze the driving force of surface evapotranspiration in the study area.Through comparative analysis,it was found that the geographically weighted regression model can better fit the data and solve the spatial heterogeneity of the data.It can perform a more complete analysis in conjunction with the spatiality of the data.The constructed driving force analysis model shows that the change of land use type and regional precipitation play an important role in the change of surface evapotranspiration,and the influence of elevation on evapotranspiration is smaller than other factors.