Analysis And Simulation Of Land Use/Land Cover Change In Hefei City Based On Spatiotemporal Data Fusion Of Remote Sensing

With the accelerating urbanization process,the economy of Hefei City has developed rapidly in recent years,and the construction land has been expanding,the cultivated land has been greatly reduced,the ecological environment has been destroyed,and the contradiction of land use has become increasingly intensified.Land use/land cover(LULC)research is particularly important,and prediction of LULC is not only important for analyzing land cover change,but also important for guiding rational land use planning and management.At present,remote sensing technology has been widely used in LULC research,and its characteristics of large-scale simultaneous observation can meet the requirements of spatial and temporal continuous analysis of LULC.However,due to the trade-off between spatial and temporal resolution due to technical and budgetary constraints,it is difficult to use existing remote sensing images to simultaneously describe spatial heterogeneity and temporal variation in LULC prediction.In order to solve this problem,this study takes Hefei City,Anhui Province as an example,and uses spatio-temporal data fusion(STF)to obtain high spatial and temporal resolution summer remote sensing images.This paper analyzes the spatial and temporal evolution characteristics of LULC in Hefei City over the past 30 years,discusses the feasibility of STF in LULC prediction,and predicts future LULC(2020,2022,2027 and 2032).This article produces the following results:(1)The data obtained from STF is applicable to LULC prediction with high availability and effectiveness.In this paper,the fused data and actual data are compared and analyzed from the quantitative and qualitative aspects.From the results analysis,the fused data of phenology,the types of terrain characteristics and spatial distribution and very close to the actual data,and the mean absolute error(AAD)is low,and correlation coefficient(R2)value is high,show that STF can better capture the reflectance change.We further compared the prediction results based on fused data and actual data,and found that their prediction results were extremely similar with high accuracy.Therefore,it can be concluded that the data obtained by STF are applicable to LULC prediction and have high availability and effectiveness.(2)The high temporal resolution remote sensing data can shorten the interannual interval in the prediction process,obtain the LULC prediction results in a specific year,and improve the prediction accuracy.After confirming the feasibility of the STF method in LULC prediction,we obtain high spatial and temporal resolution summer remote sensing data to compare the LULC prediction accuracy at different inter-annual intervals.This study uses LULC maps for 1987,1997,2002,2007,2011,2012,and 2014 to predict LULC maps for 2017.The overall accuracy of the 3,5,10 and 15 year interannual interval were 90.48%,87.76%,85.10%and 82.36%,respectively,and the kappa coefficients were 0.8200,0.7767,0.7185 and 0.6578,respectively.We conclude that the STF method can shorten the interannual interval of prediction,improve the accuracy of LULC prediction,and then obtain LULC data for specific years,and plan for future land use and Ecological environment protection provides a reliable basis.(3)Analysis of dynamic evolution characteristics of land use in Hefei City.Based on the STF method,Landsat data for 1987,1992,1997,2002,2007,2012 and 2017 were used to analyze LULC information.From 1987 to 2017,the area of cultivated land decreased from 77.83%to 63.82%;the area of construction land increased from 13.17%to 27.47%;the area of waters and vegetation showed a downward trend,but in general,they were in a relatively stable state(water area decreased from 6.12%to 6.03%and vegetation area decreased from 2.88%to 2.68%).Due to the intensification of urbanization in Hefei City,the natural landscape has rapidly turned into an artificial landscape in the past 30 years.Hefei City needs to strengthen the protection of ecological civilization and the protection of green space and water resources.(4)Analysis of LULC prediction results in Hefei City.According to the LULC data from 1987 to 2032,the cultivated land,water and vegetation area decreased by 33.14%,2.03%and 16.36%respectively,and the construction land area increased by 200.46%.From 2017 to 2020,the average annual growth rate of construction land and the average annual reduction rate of cultivated land will reach a peak(the average area of construction land will increase by 3.18%per year,and the area of cultivated land will decrease by 8.00%per year on average).The rate of urban expansion will peak in the three years from 2017 to 2020 and will slow down after 2020.In the next three years,coordinating land use and protecting the urban ecological environment is a major challenge,especially in the formulation of sound urban development plans.