The Minimum Distance Forecological Security From The Perspective Of Thermal Environment

With the concept of "minimum ecological safety distance" first put forward by the ministry of environmental protection of China in 2014,the ecological safety within and between cities has gradually attracted social attention,and the minimum ecological safety distance based on thermal environment has gradually become the focus of people's attention.Based on the thermal environment of urban agglomeration minimum ecological safety distance is to prevent the urban thermal environment risks and safeguard the human livable environment,city between bearing human economic and social activities of urban land interval distance as ecological buffer zones,in order to maximize the ecological land use cooling efficiency,thus thermal environment superposition between pollution in cities.Measurement based on the thermal environment Angle of view,therefore,the minimum ecological safety distance between cities,not only be able to set up the urban development of "rigid boundaries" and provides the theory basis for "bottom line" ecological security,also be able to solve the city focus on the apparent conflict of urban thermal environment and adding new environmental problems,such as to provide scientific reference.Dalian is one of the cities under the jurisdiction of liaoning province,located in the southernmost part of liaoning province.In recent years,with the rapid economic development of dalian,the total population keeps increasing,and the space of urban built-up areas keeps expanding to the surrounding areas.At the same time,there is a big gap between the development level of the main urban areas of dalian(zhongshan district,xigang district,Shahekou District,ganjingzi district)and other urban areas.Therefore,measuring and analyzing the minimum ecological safety distance from the perspective of thermal environment has important practical significance and value for rational planning of urban space.In view of this,this paper takes dalian as an example,based on the thermal environment under the perspective of minimum ecological safety distance is the essence of the connotation,combination of remote sensing images from 2013 to 2017,administrative boundaries,boundaries,proper use of gaussian mixture model and heat island signal function of the calendar year within the urban heat island in dalian area and the minimum distance measure,ecological security and deal with the superposition of pollution caused by hot environment,five kinds of solution are given.The main conclusions are as follows:(1)From 2013 to 2017,the total area of urban heat island in all urban districts of dalian expanded from 1657.3km2 to 6300.1km2.In 2014,the superposition of the thermal environment between jinzhou district and xishagan district was the first occurrence,indicating that the ecological environment between the two cities was polluted by the thermal environment.In 2015,superimposed areas of thermal environment appeared successively between pulandian city and wafangdian city.In 2017,thermal environment superimposed areas also appeared between lushun district and central xishagan district,and between jinzhou district and pulandian city.During these five years,no superposition of thermal environment occurred between zhuanghe city and other urban areas,indicating that the ecological environment inside zhuanghe city was relatively safe.(2)During these five years,the minimum ecological safety distance from the perspective of thermal environment in each urban area of dalian city gradually declined.To cope with the pollution caused by the thermal environment,we can adopt such schemes as selecting reasonable urban building layout,improving the greening rate of the city,making full use of urban water bodies,applying new energy and new technology,and preventing air pollution,so as to reduce the heat island effect inside the city and alleviate the pollution caused by the superposition of the thermal environment.