Ecological network analysis of an urban energy metabolic system: Model development, and a case study of four Chinese cities

Urban metabolism research faces difficulties defining ecological trophic levels and analyzing relationships among the metabolic system's energy components. Here, we propose a new way to perform such research. By integrating throughflow analysis with ecological network utility analysis, we used network flows to analyze the metabolic system's network structure and the ecological relationships within the system. We developed an ecological network model for the system, and used four Chinese cities as examples of how this approach provides insights into the flows within the system at both high and low levels of detail. Using the weight distribution in the network flow matrix, we determined the structure of the urban energy metabolic system and the trophic levels; using the sign distribution in the network utility matrix, we determined the relationships between each pair of the system's compartments and their degrees of mutualism. The model uses compartments based on 17 sectors (energy exploitation; coal-fired power; heat supply; washed coal; coking; oil refinery; gas generation; coal products; agricultural; industrial; construction; communication, storage, and postal service; wholesale, retail, accommodation, and catering; household; other consuming; recovery; and energy stocks). Analyzing the structure and functioning of the urban energy metabolic system revealed ways to optimize its structure by adjusting the relationships among compartments, thereby demonstrating how ecological network analysis can be used in future urban system research.     

打造与城市和谐发展的都市型钢厂的实践和探索

介绍了太原钢铁(集团)有限公司探索城市钢厂与城市和谐发展的实践。太钢结合自身的具体情况,通过全流程技术改造和创新,转变钢厂发展方式,承担社会责任,建设资源节约型、环境友好型企业,产品质量、能源消耗、环境保护水平显著改善,成为城市节能减排、构建循环经济的有机组成部分。     

基于分形理论的农村居民点空间特征研究——以北京市平谷区为例

空间结构与空间形态相互联系、相互作用,共同构成农村居民点空间特征,对二者的综合分析可更好地考察农村居民点用地布局特点。基于分形理论,在总体与部分两个层次上对2004-2012年北京市平谷区农村居民点空间结构与形态特征及其动态变化进行综合分析,并提出空间结构合理优化及空间形态稳定性提高相关对策。研究表明,平谷区农村居民点空间结构和形态分形特征显著。全区尺度上,聚集维数、关联维数随时间变化而减小,形态维数值持续增大,农村居民点空间结构呈聚集发展态势,空间结构自组织不断优化,但形状特征日趋复杂,稳定性降低;分乡镇尺度上,部分乡镇存在空间结构松散、关联性较弱等问题。未来需加强交通等基础设施建设,增强居民点体系内各要素关联度,促进空间结构优化;并科学编制乡村土地利用规划,降低土地利用空间发展的随意性。研究可为优化农村居民点布局,科学指导农村居民点用地调整提供参考。     

A new regeneration approach to cation resins with aluminum salts: application of desalination by its mixed bed

A novel method for the regeneration of cation exchange resins by aluminum (Al) salts was investigated in order to improve the regeneration efficiency of resins and reduce the dosage of regenerant. The influences of Al³⁺ concentration and the pH of regeneration solution on resin transformation had been studied. The desalination experiments were carried out to evaluate the characteristics of the Al form resins. Experimental results showed that the regeneration rate of resins was strictly dependent on Al3+ concentration and the pH of the solution. Compared to the conventional regeneration method, the Al form mixed bed exhibited the same desalination capability as the H form mixed bed (MB), and the total organic carbon (TOC) removal was up to 90%, clearly higher than that of the H form. Al salt solution could be utilized repeatedly to regenerate Al form resins.     

武汉城市群城镇用地空间扩展时空特征分析

基于Landsat影像数据,利用遥感和GIS技术获取了武汉城市群地区3个阶段(1980—1990、 1990—2000、 2000—2010年) 的城镇用地信息,采用城镇扩展指数和城镇扩展模型分析了城镇用地扩展的时空格局、 过程及其驱动力。结果表明:①武汉城市群城镇用地空间迅速扩张,三个时段内的城镇扩展强度指数依次为0.073 2、 0.028 9和0.099 3,呈现显著的阶段性与波动性特征;②城镇用地扩展格局具有明显的空间集中性,主要表现为以武汉为扩展中心的圈层状形态,沿武汉三环、 京广线等交通干道的轴带分布形态,不同阶段的扩展格局各具特质;③城镇用地扩展呈现"一核四带"、 "一核一带"和"三核六带"的空间扩展轨迹,与经济发展的阶段性具有明显的耦合关系;④经济体制改革、 国家非均衡发展战略、 "两型"社会建设以及长江黄金水道、 京广大动脉等交通干道建设是武汉城市群地区城镇用地变化的主要驱动因素,但各时期的主导驱动机制有所差别。     

城市生活垃圾复混肥示范工程工艺设计

提出了适合我国中小城市生活垃圾的处理办法,即利用城市生活垃圾生产有机复混肥。对有机复混肥的效益分析表明,利用城市生活垃圾生产复混具有明显的环境效益,社会效益和的经济效益,是一条利国利民,造福子孙后代的城市生活垃圾处理的好办法。     

Prioritizing urban marine habitats for conservation

Urban coastal wetlands and adjoining coves and embayments can provide habitat for significant numbers of waterbirds, despite being subject to high levels of stressors from human activities. Yet to date little emphasis has been placed on identifying these areas and prioritizing them for conservation. In this study I outline a three-step process to identify and prioritize local sites for conservation using waterbird abundance and diversity and an index of the risk to a site from marine development, and apply it to a series of urban coastal sites in two North Atlantic estuaries located in the northeast US. By combining waterbird abundance and species richness with the risk from marine development I generated a ranked list of sites with the highest listed sites having high bird diversity and low risk from development. From this list individual sites can be prioritized for conservation, and various protection scenarios can be evaluated and compared. For example, 7 of the top 10 ranked sites in Boston Harbor, combined with sites already protected under local, state, or federal statutes, represented over half of the total bird diversity in the Harbor. Similarly, in Narragansett Bay 6 of the top 10 sites when combined with sites already protected represent 48.8% of the Bay’s bird diversity. Formally protecting these sites, all of which are at relatively low risk from marine development, could result in the conservation of considerable waterbird habitat at low economic cost (i.e., from loss of development potential). Other ranking scenarios (by bird diversity alone, or by risk from marine development) were also evaluated and compared to the combined ranking. Identification of sites with high bird diversity and low risk from development could provide important information for local land acquisition groups and planning boards when considering options for the conservation of urban coastal habitats.     

Evaluation of the levels and sources of trace elements in urban particulate matter

An assessment of air quality of Belgrade, Serbia, was performed by determining the trace element content in airborne daily PM₁₀ and PM_2.5 samples collected from a central urban area. The ambient concentrations of Zn were the highest in PM_2.5 (1,998.0 ng m⁻³). Multivariate receptor modelling (principal component analysis and cluster analysis) has been applied to determine the contribution of different sources of specific metallic components in airborne particles. The obtained results showed that vehicle traffic and fossil fuel combustion in stationary objects were the main sources of trace metals in Belgrade urban aerosols.     

Urban soil-lead (Pb) footprint: retrospective comparison of public and private properties in New Orleans

Lead (Pb) is a toxin that after childhood exposure poses a lifetime of health risks. One route of exposure is soil-Pb as a result of ∼12 million metric tons of Pb residue in paint and gasoline sold in the US during the 20th Century. Pb accumulated in soil of the community is a good predictor for blood Pb of children living there. This retrospective study compares the soil-Pb on Housing Authority of New Orleans (HANO) properties with adjacent private residential (RES) properties within a 0.8 km (0.5 mile) radius. The sample subset (n = 951) is from two soil-Pb surveys (total n = 9,493) conducted between 1989 and 2000. The properties were in both the inner city (CORE) and outlying (OUTER) communities. The data were analyzed using multi-response permutation procedures (MRPP). The soil-Pb results differ significantly (P-value < 0.001) on same-aged HANO properties at different locations; thus, year of construction does not give adequate explanation for the soil-Pb differences. HANO and RES soils are significantly more Pb contaminated in the CORE than in OUTER communities (P-value < 0.001). The CORE has many more years of traffic congestion than OUTER communities; therefore, the lead additives to gasoline, and not lead-based paint, best elucidate the differences of the soil-Pb footprint at HANO and RES properties in the CORE and OUTER communites. Currently HANO properties are being redeveloped with cleaner soil, but soil on RES properties in the CORE of New Orleans remains a large source of Pb (median = 707 mg/kg in this study) for human exposure, especially children.     

Use and abuse of Pb-isotope fingerprinting technique and GIS mapping data to assess lead in environmental studies

The danger to health, especially of young children, from lead-bearing particulates in the surface environment is still a valid concern. Given the multifaceted uses of lead today as well as historically, the sources of lead must be investigated to distinguish the etiology of lead contamination on the environment. The lead isotope finger printing technique based on isotopic ratio analyses (IRA) is one of the methods used commonly for provenancing lead sources in environmental studies throughout the world. This technique, however, has some inherited shortcomings. Therefore, caution must be used in the interpretation of the results, as this technique can lead to overestimations as well as underestimations of the true source etiology/apportionment of lead in specific environments. This paper illustrates this with some examples. Data on geographical information systems (GIS) mapping in urban regions are also presented in this paper.