Simulation Of Agricultural Land Change Based On Dyna-CLUE Model

In recent years,Yunyang District is working hard for the grand goal which put forward by Shiyan to promote the construction of regional central city and to accelerate the implementation of the "one river ?three bridges and six towns" urban construction planning and the degree of integration of economic development is getting higher and higher.However,in the development of the economy,it will inevitably takes up a lot of agricultural land resources.On the other hand,Yunyang District is located in the mountains and the land on the slopes above 25°is more than others,which lead to more agricultural land distribution in the terrain at a low level,especially a large number of high-quality farmland resources are mostly distributed along the road and on the both sides of the river.However,the land for the construction of urban,industrial and mining are mostly built along the road and along the river,which will inevitably occupy agricultural land,more of arable land.This year as the "thirteen five" start of the year,it is particularly important that how to arrange the agricultural land index and the rational layout of agricultural land in the new round of land use planning.In order to achieve the goal that how to put Chinese food into the Chinese bowl,the first thing to do is to protect Chinese land.How should we do in case of food in hands and no fear,the first thing to do is to protect the same as the protection of the giant panda arable land and stick to the hectares red line.In order to prevent the disorderly expansion of the city to encroach on the surrounding high-quality arable land,the Ministry of Land and Resources and the Ministry of Agriculture have carried out permanent basic farmland delineation throughout the country.This work further strengthened the "three lines",that is,the control edge of urban,grasp the ecological red line,maintain strictly the bottom line of cultivated land.Based on this background,this article uses Dyna-CLUE and Markov models,select the Yunyang District which is located in the mountains but the economy has developed rapidly,on the basis of comprehensive utilization of LUCC,GIS and statistics,combines with Dyna-CLUE?Markov models and the improved Logistic regression analysis,studies on the temporal and spatial evolution characteristics of agricultural land in the region and The simulation of the situation of agricultural land use in Yunyang area in 2020 in the best scale,under different scenarios.The results of this study can not only reveal the characteristics of agricultural land change in Yunyang district in the application level,but also have an accurate grasp of the utilization and distribution of agricultural land in 2020,and meanwhile it has great significance to the economic development.This paper takes the second national land survey data in 2009 and the annual land use change survey data of Yunyang District in 2012 and 2015 as the main data,and takes the DEM,road,river,administrative boundaries and other vector data and economic development,population and other statistical data as the second data.Under the support of GIS technology,this paper combines with the software IDRISI which analyzes the change of land use,by using the Markov model,the change of farmland is analyzed and evaluated from the aspect of quantitative and qualitative in Yunyang District from 2009 to 2015 from different perspectives.The results of analysis reveals the spatial and temporal evolution process and regularity of agricultural land in Yunyang district in the past 6 years,selecting the best research scale suitable in this study area and the driving factors that affect the change of agricultural land,using the improved Logistic method,based on the Dyna-CLUE model,the agricultural land in Yunyang District in 2020 was simulated and analyzed under different scenarios.The details are as follows:(1)The drive factor grid of agricultural land and drive factor grid and the study of land vector database are established.The land use type is reclassified according to the national standard of land classification and LUCC classification system which studied by the older scholars and combines with the characteristics of land type and temperature and climate in the study area,meanwhile the local level is converted into model and transforms the layer of the study class into a format that the model can recognize.Meanwhile this paper collects the natural,policy and economic data that affect the change of agricultural land and transforms it into grid format,and establishes the grid and vector database of agricultural land change simulation research.(2)Establishment of temporal and spatial analysis model of land use and selection of best scale.This paper starts from the four changes in time,speed,space and quantity,calculate the dynamics,transfer and transfer rates,the land use composite index,the average elevation and the average slope of the three agricultural land,which can be a very good description of agricultural land change process of Yunyang District in the past 6 years.By setting the five different resolution of the driving factor grid,this paper takes the agricultural land in 2012 as the initial study to simulate the distribution of agricultural land in 2015 and selects the best scale by calculating and analyzing the Kappa coefficients of different resolutions.(3)The selection and treatment of driving force factors and improvement of Logistic model.According to the relativity,consistency,integrity,quantification between the driving factors and the contents of research,meanwhile attaching the equal importance between the natural and social factors,this paper selects these driving factors of agricultural land in the study area and the selected grid factor is processed.Stating the improved model,which is compared with the original model and the method of ROC is used to test the improved model and the original model.(4)The parameters of Dyna-CLUE model should be adjusted.The construction includes the construction of non-spatial modules and the construction of spatial modules.The parameters of the model include the transfer matrix of agricultural land?the limitation policy of space and the rules of agricultural land conversion.(5)The simulation of spatial change of agricultural land based on different situations in Yunyang District.In the first place,the linear interpolation and GM(1,1)model were used to forecast the annual demand of agricultural land in the study area from 2009 to 2020,and then the natural state and the permanent basic farmland protection policy which are taken as a spatial limitation policy parameter and the identified model parameters are entered into the Dyna-CLUE model,in the end,the simulation of agricultural land use was carried out in the study area in 2020,and the results of the two simulated scenarios were compared and analyzed...