Analysis Of The Evolution And Driving Forces Of Ecological Environment Quality In Ningxia

Since the new century,the impact of human activities on the ecological environment has gradually increased.The ecological environment is the totality of all external conditions that affect the survival and development of living things,and the report of the 20 th Party Congress proposed a high-level planned development in harmony with nature.Ningxia is an important junction of the Silk Road and an important ecological barrier in the upper reaches of the Yellow River.An objective assessment of the spatial and temporal structure of the quality of the ecological environment in Ningxia and the study of the driving mechanism will help promote ecological protection and civilization building in Ningxia.Taking Ningxia Hui Autonomous Region as the study object,this paper builds the RSEI remote sensing environmental index model based on the Google Earth Engine cloud platform calling Landsat remote sensing data,analyzes the spatial and temporal characteristics of environmental quality changes in Ningxia and investigates its driving force.The driving factors were also investigated.The results are as follows.(1)The RSEI model effectively integrates information from four component indicators(humidity,greenness,dryness and heat),the average correlation coefficients between the component indicators are 0.644,0.636,0.569 and 0.695 respectively,the average correlation coefficient between RSEI and the four component indicators is 0.705,the integrated correlation is higher than the average correlation between the four component indicators,and thus the RSEI model better reflects the environmental status of the study area than a single indicator.Moisture and greenness indicators are positively correlated with the model,while drought and heat indicators are positively correlated with the model.(2)Ningxia’s overall ecological quality from 2000 to 2021 can be divided into four stages: quality decline(2000-2005),quality improvement(2005-2015),quality decline(2015-2018)and quality improvement(2018-2021),with 2005-2015 rapidly improving(2005-2008)and gradually improving(2008-2015).(3)The classification of environmental quality in the study areas shows that most have good and moderate assessments,while areas with poor assessments have a relatively small percentage.From 2000 to 2021,the area of improved ecological environment quality in Ningxia,which is more than the degraded area,indicating that the overall ecological environment quality has improved.Depending on the sub-region,the area of improved and degraded green development zones in the north is almost the same,the area of green development zones in the center is slightly larger than the degraded area,and the area of improved water protection zones in the south is much larger than the degraded area.(4)From 2000 to 2021,in terms of trend change,the ecological quality of 3/4 areas in Ningxia region showed a positive trend,of which about 1/5 of them showed a significant positive trend.In terms of stability,the ecological quality of the environment in Ningxia region is relatively stable during the study period,moderate fluctuations occur.In the future,weak fluctuations in environmental quality will occur in most areas of Ningxia,and environmental protection in this region should be further strengthened.(5)The results of the geodetector show that the natural factors have the greatest influence on the regional ecological environment quality,the human activities represented by nighttime lights among the socio-economic factors are closely related to the regional ecological environment quality,and the distance from the administrative center and from the highway among the locational factors have a greater influence.The interaction of various influencing factors has a significantly greater impact on the ecological environment quality than the single-factor effect.There is no significant difference between precipitation and temperature,precipitation and elevation,soil type and night light,which have a more similar mechanism on the spatial distribution of ecological environment quality in Ningxia.When the average annual temperature,elevation,slope and precipitation increased,the mean value of RSEI increased and then decreased,and the socio-economic factors showed a negative correlation on the value of RSEI.Among the location factors,the mean value of RSEI increases with the increase of distance from stations and railroads,and then remains stable.