Study On Spatio-Temporal Evolution And Prediction Of Three-Dimensional Ecological Footprint In Yibin

With the rapid development of industrialization and urbanization,the consumption of natural resources in the region is increasing,resulting in various ecological and environmental problems and making regional sustainable development problem facing severely challenged.To determine whether a region is in a sustainable state,it is necessary to quantitatively assess the utilization of regional natural capital,thereby the ecological footprint model is put up with to solve this problem.As an improvement of the traditional ecological footprint model,the three-dimensional ecological footprint model can measure the occupancy of human capital on flow capital and stock capital respectively,and can more comprehensively and accurately reflect the utilization of natural capital in the region,which is of great significance for evaluating the sustainable development of the region.Yibin City is located in the upper reaches of the Yangtze River and the lower reaches of the“Golden Triangle”area of the Jinsha River and the Minjiang River.It plays an important role in protecting the ecological security of the entire Yangtze River Basin,however,it is sensitive to the ecological environment.In recent years,with the rapid advancement of urbanization in Yibin City,natural resources such as cultivated land and grassland have been continuously occupied,which poses a major threat to the ecological security of the region.Therefore,making scientific measurement of the resource occupation status of Yibin City and correct understanding of the ecological environment issues is conducive to promoting regional sustainable development and providing reference and example for the construction of ecological barriers in the upper reaches of the Yangtze River.This paper uses the three-dimensional ecological footprint model to measure the breadth of per capita footprint,the depth of per capita footprint and the three-dimensional ecological footprint of each district in Yibin City from 2005 to 2016,and analyzes the temporal and spatial evolution characteristics of three parameters.Based on this,it adopts BP neural network model to predict the per capita three-dimensional ecological footprint and per capita ecological carrying capacity of each district and county in Yibin City from 2017 to 2020,measures and divides the ecological sustainability index of each district and county.Finally,this paper put forward corresponding countermeasures and suggestions for each district and county of Yibin City.The main research conclusions are as follows:(1)Analysis from the prospective of time series:During the study period,the time variation of per capita footprint,depth of per capita footprint and per capita three-dimensional ecological footprint of each district and county is fluctuating,and most of which are characterized by periodic changes.The breadth of per capita footprint showed a trend of rising first,then falling,and finally changing smoothly.The highest annual average value in the study period was Changning County,with a value of 0.3079 hm~2/person.The per capita footprint depth generally showed a trend of rising volatility,reaching the peak of the study period in 2011;Cuiping District has the highest per capita footprint with an average annual average of 6.1069.The per capita three-dimensional ecological footprint of each district and county showed a general upward trend;In general,the resource endowment and economic development level were positively correlated with the per capita three-dimensional footprint value,that is,the area with good resource endowment and economic development level has the greater per capita three-dimensional footprint value.(2)Analysis from the prospective of spatial pattern:The breadth of per capita footprints generally shows a distribution pattern with low middle and high sides values.Generally speaking,in areas with a high per capita footprint,the resources in the region are relatively rich and the ecological capacity of the region is high.It is showed that the depth of per capita footprint is high in the east and low in the west.Due to its dense population and low level of capital flow,Cuiping District has maintained a high level of capital consumption in order to maintain regional development.The basic pattern of the three-dimensional ecological footprint per capita is high in the southeast and low in the northwest.(3)Analysis from the prediction results of 3d ecological footprint of each district and county:the three-dimensional ecological footprint and per capita ecological carrying capacity of most districts and counties in the study area showed an increasing trend year by year.According to the evolution trend of the ecological sustainability index of each district and county,the ecological pressure of the northern and southeastern districts and counties in Yibin city is obviously increased,and the ecological pressure of the central districts and counties is decreased.Specifically,the ESI values in Cuiping District,Yibin County and Nanxi District continued to decline,showing that they were the pressure rise zones;the ESI values of Gong County and Xingwen County showed a steady and decreasing trend,showing that they were the pressure warning zone;the ESI values of Jiang’an County,Qilian County,Pingshan County,Changning County and Gao County continued to rise,showing that they were pressure drop zones.