Study On Ecological Security Remote Sensing Assessment Model And Method Of Highly Developed Urban

Ecological security refers to the health and integrity of the ecosystem,and urban ecological security emphasizes the ecological system of urban survival and development of the security function and is the foundation and core of a national or regional ecological security.In recent years,with the explosive growth of the population and the acceleration of the urbanization process,urban ecological sustainable development is mentioned unprecedented height.With the rapid development of GIS/RS technology,the problem of spatial data acquisition in previous ecological security research has been solved to a certain extent.However,the current for ecological security research,the human highly interfering information is not prominent enough.And for the development of urban space,the evaluation of ecological security status is difficult to meet the requirements of current urban ecological security dynamic assessment and early warning analysis.In this study,the highly developed city Beijing was selected as an example,based on the PSR method,coupled remote sensing and nighttime lighting data,established a highly developed urban ecological security index system,remote sensing evaluation model,and ecological security early warning assessment system.With grid as an evaluation unit,from the time and space scale reveals the highly developed city of ecological security characteristics and evolution pattern,achieve the urban ecological security dynamic assessment and early warning analysis.The main results and conclusions are as follows:(1)Aiming at the problem of mixed pixel,this study presents a new method,which for the assessment of eco-environmental quality of vegetation information extraction of urban underlying surface with the grid as the assessment unit,which avoids the problem that the pixels with small proportion of vegetation distribution are often regarded as non-vegetation areas,and provide technical support for ecological environment quality assessment.(2)With nighttime lighting data,constructing the ecological security remote sensing evaluation model for highly developed cities,the results show that the rapidpopulation growth and the rapid expansion of urban land are closely related to urban ecological security.During the period of 1995-2010,the ecological security pressure P and the state S are deteriorating trend.The proportion of low,medium and low safety areas decreases from 2010 to 2015,the proportion of medium and high safety areas increases,and the urban ecological security is larger improve.(3)The results of safety early warning assessment show that: in 2010,compared with 2005,the area of ecological security early warning in Beijing increased.Among them,the warning for rapid degradation area accounted for up to 3%,warning for degradation trend area accounted for more than 10%.Compared with 2010,the ecological security has made considerable progress.The proportion of warning for insecurity areas decreased from 3% to 0.5%,and the proportion of warning for rapid degradation areas and warning for slow degradation areas were reduced to 2% and5.5%,in addition to upgrade trend area increased dramatically.(4)The evaluation and warning analysis results show the correctness and operability of the evaluation model.Based on the GIS/RS technology,using evaluation model constructed in this paper,can dynamically identify the urban ecological security,and provide technical support for the urban ecological planning and dynamic warning of the large central cities with unreasonable system development and spatial development.