Study On Ecological Security Of Main Cities In Northwest China Based On Improved Ecological Footprint Model

With the advancement of the "Belt and Road" national strategy,Xi'an,Yinchuan,Lanzhou,Urumqi,and Xining,the major cities along the Silk Road in the northwest China,will usher in unprecedented opportunities for development.However,the fragile ecological environment in the northwest region will become an obstacle to development.The assessment of its ecological security status and the proposed countermeasures for improving ecological security have certain practical significance.This paper using the improved ecological footprint model to analyze the long-term changes of five cities.By calculating the city's ecological footprint,ecological carrying capacity,the ecological footprint of million yuan GDP and ecological pressure index from2006 to 2015,and based on the evaluation criteria of the ecological pressure index,the ecological security levels of the five cities in the northwest are divided,and then the trend of changes in ecological security over the years is analyzed.Finally,pointed out the main ecological problems of the five cities at present.Then combined with the local conditions,making a few points to reduce the ecological deficit and improve the ecological security.The main conclusions of this paper are as follows:(1)This article improved the ecological footprint model from the following aspects:replaced the global hectare by district-area,replaced the static global average production capacity by dynamically changing average productivity of various biological resources in the five provinces,replaced static equilibrium factors by dynamic equilibrium factors,replaced static yield factors by dynamic yield factors,replaced consumer biological resources accounts with productive biological resources accounts,the reassignment of land type to livestock product footprint,added pollution accounts and water accounts.These improments maked up for the regrets as follow:Ignored the impact of regional differences,equilibrium factors and yield factors' dynamic changes on ecological footprint.Except that,the traditional ecological footprint model was indistinct between the productive footprint and the consumer footprint,the classification of the category of livestock products does not consider the ratio of feed,ignored other ecological functions in the water,lack of assessment of the impact of pollutants on the ecological environment and so on.The purpose of this article is to establish a series of parameters that are more in line with the actual situation in the northwest.The improvement of the ecological footprint model complements the literature in this area and has certain theoretical value.(2)The per capita ecological footprint,per capita ecological capacity,and per capita ecological deficit of the five cities were generally on a downward trend.In this paper,by studying the dynamic changes of the equilibrium factor and the average production capacity of five provinces,it was found that both of them have changed in the long-term sequence.Therefore,the calculation result of the per capita ecological footprint is different from the calculation result of the traditional model.(3)In the composition of per capita ecological footprint,the proportion of cultivated land footprints in all cities was in the first place,and there was a declining trend.The proportions of energy land and construction land were all in the top three,and both show an increasing trend.In addition to Urumqi,the proportion of polluting areas in the other four cities also increased.Per capita ecological capacity constitutes the largest proportion of cultivated land,followed by construction land,and the proportion of cultivated land showed a downward trend,and the proportion of construction land has increased.(4)From 2006 to 2015,there were ecological deficits in five cities in the northwest.The per capita ecological footprint was multiple of the bearing capacity,which was 18.20 times that of Xi'an,13.53 times that of Yinchuan,11.10 times of Lanzhou,29.15 times of Xining,and19.43 times of Urumqi.The ecological security of each city was threatened,and the ecological pressure index and ecological security level generally showed a decreasing trend.The level of ecological safety of each city was: Lanzhou(Grade 2,safer)> Yinchuan(Grade 2,safer)> Xi'an(Grade 4,moderately unsafe)> Urumqi(Transition from level 5 to level 4,Grade 5 unsafe t,grade 4 moderately unsafe)> Xining(Level 6,extremely unsafe).(5)Based on the analysis of ecological footprint and ecological carrying capacity in each study area,the ecological environment problems in the northwestern region mainly including:cultivated land area decreased,(equalization factor was reduced from 10.71 to 8.35),the scale of construction land increased rapidly(per capita footprint and carrying capacity's annual growth rate of construction landin of the five cities was 135.47% and 23.39%respectively,irrational energy consumption structure,low efficiency of energy use,the discharge of pollutants increased,large production and domestic water consumption,the water resources were wasted,and the ecological environment with great pressure,the ecological security situation is not optimistic.