Spatial Influence And Simulation Of Urban Expansion On Cultivated Land Space In Hexi Corridor

Oasis towns in the arid areas are the key areas of the national “The Belt and Road” strategy and the “Western Development” Strategy.They are also the fragile ecological environment areas with the highest population concentration,the most intense human activities,and the most prominent “human-land” relationship in the arid area.With the rapid development of urbanization,the arid regions are facing increasing pressure from population and cultivated land resources and the ecological environment.As a typical oasis town in the arid area,the Hexi Corridor area was a key northwest granary in China.In recent years,drastic changes have occurred in the cultivated land of cities and oasis in this area,especially the expansion of urban construction land on the limited cultivated land resources in the arid area.very serious.The study takes Hexi Corridor area as a typical case area,which is of great significance for revealing future urban development planning and effective protection of cultivated land in arid areas.This paper systematically summarizes the current research progress at home and abroad.Under the support of related research theories,a comprehensive use of GIS spatial analysis,Markov chain model,cellular automata model,multi-scenario analysis,etc.is used with the help of multi-source remote sensing data and land-use change data.The method explores the characteristics and laws of the temporal and spatial changes of urban land and cultivated land in the Hexi Corridor area,simulates and predicts the changes in urban and cultivated land in the Hexi Corridor area,and further discusses the conflict between urbanization and farmland productivity in the Minqin County under different scenarios.From a holistic perspective,we analyze and analyze the different urban growth models.The results show that:(1)According to the analysis of the current situation of the utilization of urban land and cultivated land in Hexi Corridor,the general characteristics of land use in Hexi Corridor are mainly unused land and grassland,and urban land and cultivated land only account for 0.63% and 6.35% of the total area of the study area.In general,the land use structure of Hexi five cities is consistent with the overall characteristics of Hexi Corridor,mainly including the unused land and grassland.In particular,the grassland area of Zhangye City is larger than the unused land area,and the grassland accounts for 38.07% of the total land area of Zhangye City,while the unused land accounts for 36.73%,and the other cities show the largest proportion of the unused land.The spatial distribution characteristics of oasis towns in Hexi Corridor are closely combined with cultivated land,that is to say,there are cultivated land around the areas with towns.(2)Based on the analysis of the temporal and spatial evolution of towns and cultivated land in Hexi Corridor,it is found that the urban construction land area and cultivated land area in Hexi corridor have the same trend of change,decreasing first and then increasing.Specifically,the cultivated land area in Hexi Corridor has experienced the change process of "decrease sharp increase steady increase",while the urban construction land area has experienced the change process of "decrease increase steady increase sharp increase".Through the analysis of the internal conversion relationship,we find that the cultivated land conversion has obvious spatial characteristics,and the contribution rate of different regions in different periods is quite different.15.67% of the urban expansion land in Hexi Corridor comes from cultivated land,and the rest mainly comes from unused land such as grassland,desert and Gobi.52.87% of urban expansion land in Wuwei city comes from cultivated land,while that in Jinchang city is only 0.09%.(3)Combining Markov model and ANN-CA model to predict the impact of urban expansion on cultivated land in Hexi Corridor,it is shown that the cellular automata combined with artificial neural network and adaptive inertia competition mechanism is used to simulate the land use of Hexi Corridor in 2015,and the OA and kappa coefficients show good simulation effect,and the simulation accuracy and reliability meet the requirements,which can be used to predict the type of multi-purpose land.The prediction results show that 79.77% of the urban expansion land in the Hexi corridor will come from the surrounding cultivated land in 2015-2030,and the urban central city in the arid area will still be the focus of the future oasis urban development.The urban spatial expansion mode is mainly the extension expansion,and the pressure of the future cultivated land will be greater.(4)Minqin County in Hexi corridor area is a case study area,which makes a trade-off analysis between urban expansion and cultivated land productivity.The classification schemes of land use competition under different scenarios produce different results.The selection of normal development schemes has no effect on reducing the land use competition in the study area.Under the scenario of protecting cultivated land,the land competition can be reduced,but the suitability of urbanization is low.The regional side of development competition Based on the coupling development plan of normal development and cultivated land protection,a compromise plan considering the impact of both urban and cultivated land types was obtained.However,the trade-off may be very different from the historical growth that is emerging.Policy makers and urban planners need to gradually change the urban growth path by building urban infrastructure and attracting future population.