Study On Spatialtemporal Difference Of Land Use Intensity And Its Influencing Factors

It is of great significance to identify the influencing factors of land use intensity for adjusting and optimizing the land use structure,alleviating the contradiction between human and land,and promoting the sustainable development of regional economy.Taking the middle and lower reaches of Shule River Basin as the research case,based on the data of land use and social economy in the middle and lower reaches of Shule River Basin from 1987 to 2015,the spatial-temporal heterogeneity of land use intensity and its influencing factors from 1987 to 2015 was analyzed by using land use intensity index and SFA model.The results show:(1)From 1987 to 2015,the land use structure which was dominated by deserts changed significantly in the middle and lower reaches of Shule River Basin.The deserts still dominated,over 80%.The comprehensive land use dynamic degree increased from 0.06% to 0.18% in the middle and lower reaches of the Shule River Basin.The single land use dynamic degree of grassland and water area changed from-0.51% and-1.14% to-0.9% and-0.9% respectively;the expansion rate of forest land,cultivated land and construction land continued to increase.On the spatial scale,the spatial pattern of land use expanded by centering on Guazhou county and Yumen City,and the intensity of land use extended from the center of high density to the surrounding of low density in 1987 to 2015.(2)The intensity of land use in the middle and lower reaches of Shule River Basin increased gradually,with an annual increase of 1.22 and 35.36 in 29 years.Among them,the land use intensity increased the fastest from 1996 to 2007,reaching 24.17,accounting for 68.35% of the total intensity value.After 2007,it still increased,but compared with the previous stage,it tended to be flat.The spatial pattern changed from "low in the East and West,high in the middle" to "high in the East and middle,low in the west".The intensity of land use in Changma irrigation area and Huahai irrigation area is diversified in types and multi-level in intensity.The overall intensity is higher than that in Shuangta irrigation area,and the intensity of land use in the three irrigation areas has increased to some extent in different periods.In the middle and lower reaches of Shule River Basin,the intensity of land use in villages and towns is in a relatively stable state,forming a "low-high" and "high-high" agglomeration state locally.(3)The spatial-temporal differences of influencing factors of land-use intensity change in irrigation area scale are significant.The change of land-use intensity in three irrigation areas from 1987 to 1996 is related to agricultural production structure and migration.From 1996 to 2007,affected by land-use change and migration,from 2007 to 2015,it is significantly related to agricultural production structure and land-use change.This is related to the "two West" agricultural construction resettlement project,"Shule River Basin agricultural irrigation and resettlement comprehensive development project(1996-2006)" and other policy implementation,which is consistent with the reality,that is,the relationship between land use intensity and policy is significant.