京津冀地区污染物排放与城市化过程的耦合关系

我国快速的城市化发展不仅带来了经济的迅速发展和人口的大量聚集,同时也对资源和环境产生了巨大的影响。在城市化进程较为快速的城市群地区,城市化带来的生态环境胁迫尤为突出。以典型污染物为指标,定量研究了京津冀地区13个城市在2000年、2005年、2010年的工业和生活污染物的排放总量、人均排放量、排放效率、排放强度的时空特征,研究了经济发展与污染物排放的定量响应模式,以探讨污染物排放与城市化的耦合关系。研究发现:(1)京津冀地区的污染物排放空间分异特征显著,其中北京的生活污水、生活COD等污染物排放总量为地区内最高,唐山、天津、石家庄等城市的工业污染物排放高于其它城市。(2)北京、天津工业污染物的排放效率较高,人均排放量、排放强度低于其它城市。(3)2000—2010年间,京津冀地区的生活污水、工业废气、工业固废排放显著增加(P0.05),而其它生活和工业污染物排放量、排放效率和排放强度等呈显著下降趋势(P0.05)。(4)京津冀地区的工业废水、工业和生活SO2、生活烟尘、工业固废和工业废气等污染物的排放量与经济发展存在环境库兹涅兹曲线特征(R20.5,P0.05)。定量揭示了京津冀地区污染物排放的时空分布特征及其与城市化发展的关系,可为城市群区域污染物排放的管理及环境保护政策的制定提供科学参考。

Spatiotemporal variations of pollutant emissions and their relationship with the urbanization of the Beijing-Tianjin-Hebei agglomeration

Rapid urbanization in China has led to tremendous socio-economic development, but has also caused a variety of environmental problems. The Beijing-Tianjin-Hebei (BTH) agglomeration is one of the most rapidly urbanizing areas in China, and is currently facing with considerable resource depletion challenges and severe local and regional pollution. In order to understand the impact of urbanization on regional environments, we investigated the spatiotemporal characteristic of the emissions of 10 types of pollutants in the 13 cities in the BTH region, from 2000 to 2010. The pollutants included:domestic sewage (DS), industrial waste water (IWW), industrial and domestic chemical oxygen demand (ICOD; DCOD), industrial and domestic sulfur dioxide (ISO₂; DSO₂), industrial and domestic smoke and dust (ISD; DSD), industrial solid waste (ISW), and industrial waste gas (IWG). Pollutant emissions per capita (PEPC), pollutant emissions per unit of GDP (PEPUG), and pollutant emissions per unit of area (PEPUA) were calculated for 2000, 2005, and 2010. We further examined the relationship between the emissions and economic development to investigate whether pollutant emissions in the region fit an environmental Kuznets curve (EKC). The results showed that:(1) There was considerable variation in the pollutant emissions among the cities. Four cities (Beijing, Tianjin, Tangshan, and Shijiazhuang) accounted for 37% to 69% of the total pollutant emissions in the region. Higher average DS and DCOD emissions were noted for Beijing (942.37 million t and 116214 t, respectively) than for the other cities. In contrast, the IWW, ICOD, ISO₂, ISD, ISW, and IWG emissions were higher in Tianjin, Tangshan, and Shijiazhuang than in the other cities; (2) Compared to the other cities, the highest domestic and industrial pollutant emissions were noted in Beijing and Tianjin, respectively. However, the PEPC, PEPUG, and PEPUA were lower in these two cities than in the other cities, except for the DS pollutant. In fact, the PEPC, PEPUG, and PEPUA for DS were much higher in Beijing than in the other cities. For example, the PEPUG for DS in Beijing was 21295 kg/10000 Yuan, while the regional average was 11914 kg/10000 Yuan; (3) From 2000 to 2010, changes in pollutant emissions varied among the cities. The total PEPC and PEPUA for the DS, ISW, and IWG emissions increased for most of the cities. For example, IWG emissions in Tangshan increased from 266.6 billion Nm³ in 2000 to 1687 billion Nm³ in 2010. However, IWW, ICOD, DCOD, ISO₂, DSO₂, ISD, and DSD emissions, decreased from 2000 to 2010; and (4) There were EKC characteristics for the IWW, ISW, IWG, DSO₂, and DSD pollutants in the region (R² < 0.5, P < 0.05). The turning point for pollutant emissions typically occurred when the per capita GDP reached approximately 40000 Yuan. Overall, the considerable variations in total emissions and emission intensity among cities in the region suggested that differentiated policies and actions should be taken to either reduce the total emissions of certain types of pollutants, or increase the efficiency of resource utilities. For example, Beijing should focus more on the reduction of DS emissions, whereas Tangshan, Tianjin, Shijiazhuang, and other industrial cities should focus on controlling the emissions of industrial pollutants. The results further revealed the relationship between pollutant emissions and the degree of urban development, which enhances our understanding of the effect of urbanization on local and regional environments.