Evaluation And Analysis Of Ecological Environment Quality In Harbin Based On RS And GIS

The urban ecological environment is closely related to human life and is the basis for human survival and development.Since the 1990 s,with the rapid development of the economy,China's urbanisation process has continued to increase,and the rapid development of urbanisation has been accompanied by an increasingly complex land use structure,which inevitably has an impact on the ecological environment.The rapid development of computer technology and remote sensing technology has provided a new way to evaluate the quality of the ecological environment.As urbanisation and industrialisation continue and the population continues to increase,changes in land use patterns and structures will have an impact on the regional ecological environment.As the capital of Heilongjiang Province,the economic,political and cultural centre of the city,Harbin is developing rapidly.Therefore,this paper takes Harbin as the study area,based on remote sensing and GIS technology,and selects Landsat remote sensing data from 1984,1995,2005,2015 and 2019 as the data source to classify the ecological environment quality into five classes,based on the new remote sensing The Remote Sensing Based Ecological Index(RSEI)was used as the data source to make a comprehensive and objective evaluation of the ecological environment quality of Harbin City during the period from the Sixth Five-Year Plan to the Thirteenth Five-Year Plan.The analysis of the factors influencing the quality of the regional ecological environment was carried out through a grey correlation analysis model,with a view to providing a scientific basis for the further protection of the ecological environment in Harbin.The main findings of this paper are as follows.(1)The contribution of the first principal component eigenvalues was higher than74% for each period of data in 1984,1995,2005,2015 and 2019.the results for the four indicators on each principal component showed that the greenness indicator and the humidity indicator both had positive values and contributed positively to the ESEI,while the dryness indicator and the heat indicator both had negative values and contributed negatively to the ESEI,and the dryness indicator and greenness indicators contributed more to the RSEI.(2)The RSEI values of Harbin City between 1984 and 2019 show a trend of increasing year by year,with the proportion of the area in the study area with an ecological and environmental quality grade of medium being 56.85% in 1984,the proportion of the ecological and environmental quality grade of good being over 50%from 1995 to 2015,and the proportion of the ecological and environmental quality grade of excellent reaching 51.53% in 2019.Between 1984 and 2019,the proportion of Harbin's ecological and environmental quality grades of good and excellent increased year by year.(3)The spatial distribution of ecological quality in Harbin is characterised by "better in the north and along the Songhua River,worse in the centre and south".The areas with better ecological quality are mainly in Hulan District and most of Daowai District,northwestern Songbei District and southwestern Daoli District,while the areas with worse ecological quality are mainly in Nangang District,Xiangfang District,Pingfang District and southeastern Songbei District.(4)The change of land/cover in Harbin City affects ecological indicators,the increase of forest land affects greenness indicators and humidity indicators,the increase of construction land affects dryness indicators and heat indicators;the results of grey correlation analysis show that the RSEI of urban ecological quality in Harbin City is influenced by the area of afforestation,the average annual precipitation and the green space rate of built-up areas,and the correlation between the three indicators and the RSEI is above 0.85.The correlation between the three indicators and RSEI is above0.85,indicating that increasing the forest cover and green space rate in built-up areas is conducive to the improvement of the ecological environment in Harbin.The ecological quality of Harbin has been improving year by year.The change rule of land use structure,quantity and transfer is summarized.The increase of forest land,grassland and cultivated land will increase the vegetation coverage and water and soil conservation ability,while the increase of construction land will intensify the urban heat island effect and indirectly affect other ecological quality indexes.Combined with other social and economic factors to explore its impact on the ecological quality of Harbin City,and combined with the actual situation of Harbin to provide ecological protection countermeasures and suggestions.