Dynamic Changes Of Ecological Environment Quality In Shijiazhuang City Under The Background Of Climate Change

Shijiazhuang City is a regional center city for the integrated development of Beijing-Tianjin-Hebei,and an important economic,transportation and cultural hub in North China.In recent years,the regional economy has continued to develop,but a series of ecological and environmental problems such as air pollution,water pollution and noise pollution have also occurred frequently.An in-depth understanding of the dynamic changes in the quality of the ecological environment in Shijiazhuang City under the background of climate change will undoubtedly have important practical significance for the sustainable development of Shijiazhuang's resources,environment and social economy.As an important city node in Beijing-Tianjin-Hebei,Shijiazhuang plays an indispensable role in controlling air pollution,promoting the construction of ecological civilization,and responding to climate change.The study used Shijiazhuang's meteorological data from 1972 to 2018 to analyze the changes in water and heat conditions in Shijiazhuang.At the same time,part of the remote sensing image data from 2000 to 2018 was selected to comprehensively analyze the vegetation coverage,net primary productivity,land use,ecological livability and other aspects.Thus obtained the changes of the ecological environment quality in Shijiazhuang City.Research indicates:(1)The climate in Shijiazhuang is suitable and stable,the temperature is on the rise,and the rainfall is relatively stable on the whole.In the past 47 years,the average temperature and precipitation in Shijiazhuang City were 13.2? and 503.16 mm respectively.Shijiazhuang City has the highest increase in temperature in summer and the highest precipitation in all four seasons.(2)The overall characteristics of Shijiazhuang's vegetation coverage are higher in the northwest and southeast,and lower in the middle.Compared with 2000,in 2018,except for the decrease in the vegetation area of high vegetation coverage and low vegetation coverage,the area of other vegetation coverage levels increased compared with 2000,and the lower vegetation coverage increased nearly doubled.(3)In terms of land use,the land use/cover types in Shijiazhuang area are mainly farmland,grassland and woodland.The proportion of construction land and water area is relatively low,and the proportion of unused land is the least.The overall trend of changes in Shijiazhuang City in the past 40 years is that construction land has continued to rise rapidly,unused land and cultivated land have declined significantly,and woodland and grassland have declined,but the decline is relatively small.(4)From the perspective of the RSEI model,from 2001 to 2018,the quality of the ecological environment in Shijiazhuang was generally good.RSEI grades are mainly excellent and good,and the area of better areas has always accounted for more than 65% of the total area.From a spatial perspective,there is a big difference in RSEI grades between the east and the west of Shijiazhuang.The areas with excellent and good RSEI grades are mainly concentrated in the eastern plains and the western Taihang Mountains.The RSEI grades of the mountains where the Taihang Mountains connect with the North China Plain are lower.(5)From the perspective of ecological livability,the whole area of Shijiazhuang City is relatively livable.The livability of Shijiazhuang's ecological climate shows an overall trend of increasing from west to east.The distribution trend of livability is more obvious.The low-value areas are distributed near the Taihang Mountain with higher altitude,and the high-value areas are distributed in the relatively flat North China Plain.Regions and Southeastern Regions.The ecological climate livability from 2015 to 2018 was slightly higher than that from 2000 to 2005.