Study On The Land Use Change In Urumqi In The Past 30 Years Based On RS Technology

As the core area of the construction of the Silk Road Economic Belt and the leader of the economic and social development of the whole Xinjiang,the development of the city of Urumqi has an obvious influence on the land use structure of the Urumqi.Due to drought,scarce precipitation,lack of water resources,ecological environment and its vulnerability,the continuous expansion of urban scale not only resulted in the reduction of high quality arable land,but also a threat to the balance of the ecological environment.Based on the land use change in the remote sensing image monitoring area,this paper explores the impact mechanism of urban development on the regional environment and examines the accuracy of the results.Using the remote sensing images in 1990,2000,2010 and 2017 in Urumqi,the ENVI platform was used to supervise and classify them,and the land use status of the corresponding time points were classified.From the perspective of land use quantity change and structural change,the land use types in the whole city and various municipal districts are statistically analyzed and compared,select the social and natural driving force factors that cause land use change and sort out redundancy analysis,and select the driving factor input CLUE-S model with cumulative contribution rate greater than 80%,forecast the trend of land use change in Urumqi for the next 10 years,and verify the accuracy,the conclusions are as follows:(1)from 1990 to 2017,the area of cultivated land in Urumqi decreased continuously from 158873 hectares in 1990 to 158873 hectare in 2017,mainly because of the continuous expansion of cities and the construction of infrastructure in the last few decades.(2)from 1990 to 2017,the urban area of Urumqi was expanding outward,the corresponding construction ground increased rapidly.The area of construction land was increased by 2.5 times in the study period.The area accounted for 1.84%,2.51%,5.02%and 6.51%of the total land area in each study period.(3)the largest land use type in Urumqi is grassland,followed by other land.From 1990 to 2017,the grassland accounted for 57.36%,58.46%,56.23%and 55.95%of the total area of the whole city,while the unused land accounted for 21.44%,24.50%,24.24%and 23.79%of the total area of the city.The area of water area in Urumqi has little change and the proportion of distribution area is small.In 1990,the area of water area was 32512 hectares,to 32959 hectares in 2017,and the area increased by 446 hectares.(4)the land use diversity index,evenness index and comprehensive land use index of Urumqi from 1990 to 2017 have increased in varying degrees.The diversity index changed from 1.2189 in 1990 years to 1.2590 in 2017,and the evenness index changed from 0.6803 in 1990 to 0.7026 in 2017,and the comprehensive land use index was 1990 from 183.77 changed to 194.37 in 2017.The changes in the index are mainly reflected in the significant reduction in the proportion of grassland from 1990 to 2017,while the small area of construction land is increasing from 1990 to 2017,which leads to more and more uniform distribution of land use types.(5)according to the analysis of the change of land use types in each district and county in Urumqi,it is found that the five districts(new urban area,Toutun River District,Tianshan District,Shuimogou district and Sha Yi buck area)have the fastest change in construction land,and the problems of occupying arable land are more sudden,mainly because of the center of Urumqi.The total economy of the five districts is large,and the development is fast.According to the spatial development strategy of Urumqi,the urban boundary of Urumqi mainly develops northward,and the two are identical.In addition to the central five areas,the construction land in the East region is growing rapidly,and the construction land base is large and the increment is the most,but it is found that the land use index is relatively small according to the analysis.In the period of the study,the change range of land use in Urumqi and Dabancheng areas is small,the construction land is increased in general,and the other types of land use are reduced,but the dynamic index of land use change is small.(7)to analyze the selected driving force factors,and to sort the factors according to the factor contribution rate,and input the factors into the CLUE-model to predict the land use change for the next 10 years,and the results show that the fitting effect is better.According to the distribution of land use in 2027,it is found that the construction land in Urumqi has increased obviously.The area of the increase is mainly concentrated in the new urban area and the meadow District,and the area of other land and grassland has been greatly reduced.The prediction results have certain practical reference value.