Remote Sensing-based Ecological Security Evaluation System Construction And Ecological Quality Prediction Research

Urban expansion is gradually affecting the level of ecological quality improvement in and around cities,and how to conduct targeted and comprehensive ecological quality environmental assessment of cities has become a hot topic for scholars’research.In this paper,we refer to the Minimum Cumulative Resistance(MCR)model to calculate the ecological corridors,ecological pinch points and ecological barrier points in the Tianjin Green Ecological Barrier Area,and propose ecologically important areas that should be paid attention to in ecological improvement,which is of positive significance for maintaining the structural integrity of the ecosystem and improving the regional ecological environment in the Tianjin Green Ecological Barrier Area.It is of positive significance.This paper uses Sentinel II data,Landsat 8OLI＿TIRS data,population density data,DEM data,Tianjin road data,Tianjin Statistical Yearbook and other information products for 2018 and 2021,and uses Acr GIS,ENVI,Fragstats,PLUS and other software processing,and adopts a deep learning supervised classification method for surface cover classification The ecological safety evaluation of the green ecological barrier area is carried out by using the hierarchical analysis method(AHP)to determine the weights,the landscape pattern index,the ecological quality index(RSEI)and the PSR model,taking the control zone zoning of the green ecological barrier area and the township planning as the benchmark,with a view to calculating the influencing factors that are related to the environmental quality of the green ecological barrier area to a large extent,and analyzing the ecological environmental quality of the green ecological barrier area from the overall and detailed aspects with focus.The ecological quality changes in the green ecological barrier zone are analysed in both qualitative and quantitative terms,and the ecological quality of the green ecological barrier zone in Tianjin is evaluated and analysed in a comprehensive manner.Finally,the PLUS model based on the cellular automata model(CA)is used to predict the trend and distribution of the ecological quality of the area in2024,in order to provide a reference for the future development of the barrier area.This study is an important reference for assessing and improving the ecological quality of the green ecological barrier zone in Tianjin,and also provides support for other cities to conduct ecological safety evaluation and ecological quality prediction in ecological barrier zones and protected areas.The results of the study show that:(1)There are 369 ecological corridors in the green ecological barrier zone in 2018and 365 ecological corridors in the green ecological barrier zone in 2021;the largest proportion of general ecological corridors and the smallest proportion of critical ecological corridors;the proportion of general ecological corridors and critical ecological corridors together account for 98%and above of the total proportion,and the distribution characteristics of the three types of ecological corridors are obvious.2018 Green Ecological Barrier There are 76 ecological barrier points in the district and99 ecological barrier points in the green ecological barrier district in 2021;the total area of ecological pinch points in both years is 435,000m~2 and 582,500m~2 respectively,and the average area of ecological pinch points has increased by 8.9%year-on-year;ecological barrier points are analysed in the standard elliptical direction,and the distribution of data in 2021 becomes smaller,and the centripetal force of data becomes more and more obvious,and the distribution of barrier points directional trend is more aggregated.(2)The two-year ecological safety index for the study area was obtained from the ecological safety system and was 0.591(critical safety)in 2018 and 0.663(relative safety)in 2021,with an increase of 12.18%.(3)The mean values of RSEI in 2018 and 2021 are 0.595 and 0.614 respectively,and the area of Tianjin’s green ecological barrier area that has become better in ecological quality from 2018 to 2021 is 4.6%more than the area that has become worse,which shows that the quality of its ecological environment is improving;the distribution characteristics of different degrees of changes in the land type transfer map are more obvious;the RSEI values of the townships in the green ecological barrier area The P and Z values of the Moran index of the townships in the green ecological barrier area are within the effective threshold,and the townships with high RSEI values in 2018have the largest Moran index values,and the townships with high RSEI are most spatially clustered relative to 2021;the RSEI indices of the jurisdictions and townships in the standard green ecological barrier area in 2018 and 2021 show a low-high-low smooth trend of rising first and then The shape is like an opposite U-shape,with the magnitude of the inverted U-shape in 2018 being relatively gentle and the magnitude of the inverted U-shape in 2021 being the most obvious.(4)The mean value of RSEI of the green ecological barrier area in 2024 is predicted to be 0.629,with the mean value of RSEI showing a uniformly increasing trend,but the trend starts to become moderate at a later stage;the overall development is in a good direction.