城市化区域生态风险驱动力及管控策略——以北京市为例

Driving forces and controlling strategies of ecological risks in urbanized areas:A case study of Beijing

快速城市化导致城市及周边区域生态风险不断增加,认知城市化区域生态风险,探究其变化的驱动因素,提出行之有效的风险管控策略,对城市化区域生态环境与社会经济协调发展具有重要意义。以北京市为例,基于生态系统服务对生态风险进行了定量表征,分析了城市化因素对生态风险的驱动作用,探究了生态风险管控策略。研究结果表明:不透水地表扩张、经济增长、人口增长均对生态风险有显著的驱动作用,其中不透水地表扩张的驱动作用占主导地位。经济增长和人口增长通过影响不透水地表率间接作用于生态风险,在2005年时,人口密度对生态风险的驱动作用大于GDP强度,在2010年及之后,GDP强度对生态风险的驱动作用则变得比人口密度的驱动作用更大。北京市的生态风险管控策略为:在不透水地表率介于40%—70%的区域降低不透水地表率和实施土地利用及景观格局优化;不透水地表率大于70%的区域应防止不透水地表进一步扩张;不透水地表率低于40%的区域需通过提升生态系统质量、强化风险防范、降低风险暴露等途径来管控风险。此外,应通过提高海淀、昌平、通州、顺义等辖区的人口和经济城市化集约水平来降低生态风险。本研究阐明了城市化对区域生态风险的驱动作用,可为北京市生态风险管控提供依据。

Rapid urbanization has been a driving force behind the continuous increase in ecological risks in both urban areas and their surrounding regions.Understanding these ecological risks in urbanized areas,exploring the factors responsible for their changes,and proposing effective risk control strategies are of paramount importance for achieving harmonious development between the ecological environment and socio⁃economics in urbanized regions.Taking Beijing as a case study,this study used ecosystem services to quantitatively characterize ecological risks,analyzed the influence of urbanization factors on ecological risks,and explored the strategies for risk control.The findings reveal that the expansion of impervious surfaces(IS),economic growth,and population growth have all had significant driving effects on ecological risks,with the expansion of IS emerging as the dominant driver.Economic and population growth indirectly affect ecological risks by impacting the impervious surface ratio.Notably,the direction and magnitude of their driving effects underwent substantial changes after the year 2010.For Beijing,the ecological risk control strategies involve addressing the IS in different IS ratio ranges.In areas with an IS ratios exceeding 70%,the primary strategy of risk reduction should be reducing the IS ratio.However,these areas tend to have high urban economic and social activity levels,making measures to reduce IS ratios socially and economically costly.Therefore,strict measures should be implemented to prevent further expansion of IS in these areas.Additionally,new urban development should be carried out with IS ratios kept below 70%.In areas where the IS ratio falls between 40%and 70%,the driving effect of IS expansion on ecological risks intensifies,while other factors simultaneously contribute significantly to increased risks.In these areas,multiple measures are recommended for risk control,such as increasing the permeability of paved surface,increasing the green space area,and building compact construction land.In areas with IS ratios ranging from 0%to 40%,ecological risks in Beijing are primarily influenced by factors other than IS.Thus,reducing the IS ratio alone is unlikely to effectively mitigate risks in these areas.Risk control strategies in these areas should focus on increasing ecosystem quality,strengthening risk prevention measures,and reducing exposure to risks.Furthermore,in districts such as Haidian,Changping,Tongzhou,and Shunyi,reducing ecological risks should involve elevating the population and economic urbanization intensity.This study offers insights into the impact of urbanization on regional ecological risks and can provide references for ecological risk control in Beijing.