THE SPATIO-TEMPORAL DYNAMIC CHANGES OF LAND USE AND ECOSYSTEM SERVICE VALUE IN LANZHOU CITY ON THE UPPER YELLOW RIVER

Using five remote sensing images, using the method of value equivalent factor and spatial statistical analysis, this paper explores the spatio-temporal dynamic changes of land use and ecological service value in Lanzhou from 1980 to 2020 in the upper Yellow River. The results showed that :(1) the grassland area accounts for more than 60 % of the natural ecosystem in Lanzhou, and the construction land increased by 228.83% after 2000, and the cultivated land decreased the most. The land use mainly showed the change characteristics of cultivated land into forest land and construction land, grassland transfer construction land. (2) The growth rate of ESV in Lanzhou was 7, 74% during the study period, of which grassland ESV accounted for more than 52%; In the individual ESV, hydrological regulation and soil conservation account for more than 40 % of the total value, (3) On the spatial distribution, the change of ESV in Lanzhou is generally consistent with the distribution of forest land and grassland. In time series, the high value area is shrinking while the low value area is gradually expanding. (4) The ESV and its changes in Five periods in Lanzhou have a very obvious positive spatial autocorrelation. The high value area tends to gather, while the low value area tends to be adjacent. Different stages show different spatial aggregation characteristics. but the ESV hot spot map is consistent with the spatial distribution characteristics of ESCI in the overall distribution.