Urban development and resource endowments shape natural resource utilization efficiency in Chinese cities

Improving the efficiency with which natural resources are utilized is an indispensable for achieving sustainable development and carbon neutrality. By analyzing the utilization efficiency of energy, water, and land, we established a comprehensive natural resource utilization efficiency index (NRUEI). We then calculated the 2016 index for 165 cities in China, and investigated what caused it to vary. We found three main results: (1) the NRUEI varied greatly across China and there were significant positive correlations between urban energy utilization efficiency (EUE), water utilization efficiency (WUE) and land utilization efficiency (LUE); (2) the NRUEI showed a significant positive correlation with a city's population size, economy (Gross Domestic Product (GDP)), and the level of urban social development (GDP per capita); (3) cities in East China have the highest natural resource utilization efficiency, while cities in Northeast China have the lowest. These results indicate that China's increasing urban development is associated with rising natural resource utilization efficiency and that the city's endowment of natural resources is an important factor affecting that efficiency. Further, the results showed that the determinants of a city's NRUEI differed in large and small cities. Lastly, our results suggest that improving EUE is key for improving NRUEI in urban China, and different efficiencies can be improved intertwined. A major takeaway of this study is that there is great potential for improving natural resource utilization efficiency in Chinese cities and we include city-specific suggestions for efficiency improvements.     

The Integration and Sustainable Development of Chengdu-Chongqing Urban Agglomeration

Urban Agglomeration is an inevitable outcome of urbanization and industrialization, and a main form of urban development. Based on the analysis of urbanization and urban system situation, this paper will discuss the integration of urban agglomeration development, using the urban area of Cheng （Chengdu）-Yu （Chongqing） Urban agglomeration （CYUA） as a case study. By means of industries, population and spatial integrations, the function, strength and competition of CYUA will be improved and this urban agglomeration will transit from a budding state to a growing and mature one in future. The sustainable development of CYUA will depend on countermeasures, such as accelerating industrialization and urbanization, building a traffic network and express roads, strengthening the ability of self-sufficiency, enlarging the ecological construction and environmental protection, and establishing the synergetic institution of cross districts.     

城市交通系统的可持续发展

从城市交通发展战略、交通规划和交通环境量化评价指标三方面，研究了可持续发展理论如何在城市交通体系中得以体现，同时给出了可持续发展观念下的城市交通规划流程。     

太湖流域城镇形态的遥感信息提取模型研究

城市形态学在城市地理学的发展过程中占有重要地位，为战后城市地理学成为一门独立学科起了重要的推动作用。20世纪50年代后，因城市形态的研究没有取得突破性的进展，城市形态的研究似乎变成传统景观研究内容的一部分。20世纪80年代后，城市化、城市郊区化进程加快，城镇研究越来越受到重视，但城市地理学者在研究城镇之前必须对城乡进行划分，而城乡划分的基础是城市形态的信息提取，因而对城市形态的研究又得到重视，但城镇形态信息提取没有找到一个切实有效的方法。利用遥感技术，以太湖流域苏锡常地区为例，建立城镇形态信息的提取模型－仿归一化植被指数法，且通过对比监督分类法，说明仿归一化植被指数法提取城镇信息的特点，为城乡划分，城镇聚落结构，城市群等研究提供客观，简便的获取城镇信息的方法。     

北京市城市发展与水环境演化规律研究

为解决北京市发展和环境的深层次矛盾,需要把握环境质量-污染结构-社会经济发展规律,研究城市发展规模、产业结构、水资源、污染防治措施等对环境质量演化的影响。分析了2000年以来首都水环境演变规律及相关影响因素,对比国外主要城市,分析了北京市水环境质量产生差距的主要原因,提出了水环境保护的综合对策和建议。研究将为解决北京市水环境问题提供参考。     

温州市龙湾区内河水质现状调查研究

龙湾区是温州市的三大城区之一,从20世纪80代以来,随着温州市经济的迅猛发展,人口的增长,龙湾区城市内河水质不断恶化。本文通过对龙湾区内河设置水质监测点,分季度采样分析,对龙湾区内河水质情况进行调查研究,分析各片区的主要污染物,为改善河道水质提供依据。     

异化铁还原对土壤中重金属形态转化及其有效性影响

铁的微生物还原是以Fe(Ⅲ)为末端电子受体在厌氧条件下氧化有机物的产能过程,在生物地球化学循环中起着重要的作用.铁呼吸被认为是地球上最古老的微生物代谢形式,与水体、土壤及沉积物中物质循环息息相关.铁的微生物还原对土壤中重金属形态转化有显著影响,对修复重金属及放射性核素污染的场地有着重要意义.本文综合评述了近年来铁微生物还原研究进展,从生态安全和可持续发展角度,探讨了异化铁还原对重金属的形态改变及重金属污染土壤修复的潜在价值,并对其应用前景进行客观分析.异化铁还原对重金属形态转化的影响机制,可初步归纳为异化铁还原对重金属的氧化还原作用、对重金属的甲基化作用、对重金属的固定作用,其作用机制包含生物过程和化学作用的相互穿插,值得进一步深入研究.     

Characterization of heavy metal desorption from road-deposited sediment under acid rain scenarios

Road-deposited sediments(RDS) on urban impervious surfaces are important carriers of heavy metals.Dissolved heavy metals that come from RDS influenced by acid rain,are more harmful to urban receiving water than particulate parts.RDS and its associated heavy metals were investigated at typical functional areas,including industrial,commercial and residential sites,in Guangdong,Southern China,which was an acid rain sensitive area.Total and dissolved heavy metals in five particle size fractions were analyzed using a shaking method under acid rain scenarios.Investigated heavy metals showed no difference in the proportion of dissolved fraction in the solution under different acid rain pHs above3.0,regardless of land use.Dissolved loading of heavy metals related to organic carbon content were different in runoff from main traffic roads of three land use types.Coarse particles(150 μm) that could be efficiently removed by conventional street sweepers,accounted for 55.1%-47.1%of the total dissolved metal loading in runoff with pH 3.0-5.6.The obtained findings provided a significant scientific basis to understand heavy metal release and influence of RDS grain-size distribution and land use in dissolved heavy metal pollution affected by acid rain.     

不同形态磺胺类药物在根-土界面的空间分布及毒性评价

采用化学分析和发光细菌检测相结合的方法,研究了磺胺类药物在作物根-土界面的形态分布及生态毒性.结果表明,磺胺类药物在根际土壤中主要以水溶态的形式存在,远根区则以有机溶剂可提取态为主要形态.3种形态磺胺类药物对明亮发光细菌的相对发光抑制率均小于30%,表现为低毒性.不同形态磺胺类药物对明亮发光菌表现的生态毒性不同,有机溶剂可提取态对明亮发光细菌的毒性最大,水溶态次之,结合态毒性最小.根际区水溶态的含量及其对明亮发光细菌的相对毒性抑制率大于远根区,而有机溶剂可提取态和结合态的含量及其对明亮发光细菌的相对毒性抑制率则小于远根区.