| Vegetation is not only an important part of the ecosystem,but also one of the main influencing factors of the underlying surface of the watershed,and it is of great significance to clarify the growth trend and trend,distribution characteristics and driving factors of vegetation in the region,which is of great significance for ecological restoration,land desertification control and sustainable utilization of water resources in the region.This paper considers vegetation,hydrology,topography and other factors,and designs soil,geophysical and groundwater experiments based on Landsat series satellite,meteorology,hydrology and DEM data.A series of work was carried out to obtain data information,and the vegetation coverage of nearly 30A Jilantai salt lake basin in 1991～2020 was inverted by using the pixel binary model,and the distribution law and evolution characteristics were analyzed,The future trend,stability and sustainability of vegetation cover in 30a were analyzed by cell-by-cell Slope trend analysis,Hurst index and coefficient of variation,Using the Peason correlation coefficient and geographic detector model,the response relationship between features and vegetation was analyzed,The influence of hydrology,topography,climate and other factors on the distribution of vegetation coverage was qualitatively and quantitatively analyzed,the status quo and change characteristics of the driving factors were extracted,and the driving degree of each driving factor on vegetation coverage was quantitatively characterized.The main conclusions are as follows:(1)From 1991 to 2020,the administrative area with the largest vegetation cover value was Bugutusum,with an average value of 0.9319,and the riverfront street had the smallest vegetation cover,with an average of 0.3010.Under the future trend,the upward and downward trend of vegetation coverage in the basin of Gelantai Salt Lake Basin is relatively scattered,and the vegetation coverage in May,June,July,August and September shows an upward trend,and the interannual vegetation coverage shows a downward trend,but the downward trend is slow.In the spatial sustainability analysis of the basin of the Gelantai Salt Lake Basin,the value of the Hurst index was between 0.16 and 0.74,of which the total area of antisustainance was 17514.65km~2,accounting for 85.79%of the total area,and the total area of persistence was 2510.41 km~2,accounting for 14.21%of the total area.The spatial stability is mainly based on instability,and the coefficient of variation value is between0%～539%,and the overall study area is unstable.(2)When the relationship between fractional vegetation cover and meteorological element response was carried out,rainfall and vegetation in July and September showed a positive correlation,and other growth periods showed negative correlation;In June,August and September,the temperature and vegetation showed a positive correlation,and the temperature and vegetation in May and July showed a negative correlation;The correlation between May,June,July,August and interannual evapotranspiration and fractional vegetation cover was positively correlated,and September was negatively correlated;The average value of interannual vegetation and relative humidity data was 0.076,showing a positive correlation.When discussing the influence of hydrological topographic elements on vegetation growth,the vegetation growth trend increased with the increase of the three types of elements:elevation,slope and groundwater.According to the aspect extraction,the fractional vegetation cover value is the highest in the northeast direction and the low fractional vegetation cover in the southeast direction.(3)Comprehensive driving mechanism of spatial differentiation of vegetation cover:the degree of interpretation of vegetation by each feature is from largest to smallest:Precipitation(0.316)>Groundwater distributionr(0.313)>Soil Type(0.294)>Elevation(0.203)>Evapotranspiration(0.196)>Relative Humidity(0.182)>Temperature(0.081)>Slope(0.026)>Aspect(0.024)>Land Use Type(0.019),Rainfall and groundwater distribution are more driven by fractional vegetation cover.Under the interaction,the elements in the study area showed two-factor enhancement and nonlinear enhancement,and two-factor enhancement was the main interaction.In the risk detection analysis,the most suitable vegetation growth intervals for each driving factor are:Air temperature(7°C～10°C),precipitation(47.9mm～55.8mm),evapotranspiration(703mm～807.9mm),relative humidity(21%～27%),elevation data(2890.75m～3159m),soil-type(semi-leached soil),land-classification(arable land),slope(>12°),aspect(northeast),groundwater distribution(1361.54m～1371.65m). |
