Spatio-temporal Simulation And Analysis Of Typical Land-surface Factors Based On Vic Model

The land-surface hydrological process in the arid areas refers to the process that occurs on the land-surface and soil in the basin,which not only can control the water and heat exchange between land and air,but also can affect climate change.Through the simulation of land-surface hydrological process under changing environment,it is possible to understand the formation mechanism,change law and distribution of water resources,and realize the optimal allocation of water resources,which is of great significance to the coordinated development of economy,society and ecology in arid areas.Based on the calculation principle and process of energy balance and soil water&heat flux of VIC model,this paper selected SMC,AET,LST as the typical land-surface factors,which all had an great impact on the global energy balance and hydrological cycle,using the three-phase image of LUCC,taking the Ebinur Lake basin as the study area,the land-surface hydrological processes in the study area from 1960 to 2017 were studied.The main research results are as following:(1)The NSE and R~2were expected to verify the runoff simulation effect of the VIC model.Among them,during the period of validation,the NSE of monthly runoff at the Wenquan and Jinghe stations were 0.438&0.120,and the R~2were 0.4678&0.2574,respectively.The R~2of simulated monthly SMC,AET,and LST data were 0.4510,0.5354,0.9785,respectively.(2)In terms of space,the average annual values of SMC in the central and eastern plains were less than that in other regions.The values of SMC in spring were mainly distributed in the western and southeastern plains,and summer were mainly distributed in the southern mountainous areas.The values of SMC in autumn and winter were lower than that in spring and summer;The areas with strong annual values of AET were located in the peripheral mountainous,and the high values of AET in spring were mainly distributed in the barren lands and grasslands near Ebinur Lake,the values of AET in the study area increased overall in summer,and the values of AET were weaker in autumn and winter,and the spatial characteristics were not obvious.The difference of average annual values of LST in the study area were not obvious.The values of LST in mountainous areas were lower than other areas in spring,the overall values of LST in the study area rose in summer,the values of LST gradually decreased in autumn and winter.In terms of time,the annual values of SMC,AET,and LST had respective trends of decreasing,increasing and increasing.(3)Each land-surface factor and each meteorological element in the study area had1 to 4 significant periods in different time-frequency domains,and the controlling factors of each land-surface factor were different.The SMC,AET,annual precipitation,relative humidity,and sunshine hours had significant areas on different time scales on1-8 a and 5-8 a,respectively.There were three correlations between the phase angle,lag,approximately positive correlation,and lead change;The LST and average temperature had different time scales on 1-4 a in the significant area,the phase angle only has one correlation relationship that is approximately positive.(4)From 1960 to 2017,the area of grasslands,croplands,and non-vegetation lands in the study area increased significantly,and the area of opened shrublands decreased sharply.Most of the opened shrublands were converted to non-vegetation lands and croplands,which may aggravate the decrease of SMC in the study area and the increase of LST.