大城市边缘区土地利用空间格局特征分析.以北京大兴区为例

以北京大兴区为例,利用景观格局和空间分析方法,从产业布局和区位角度分析大城市边缘区土地利用空间分异特征.结果表明：（1）该区土地利用程度高,区域产业布局及距城市、村镇和道路距离等区位因素使其土地利用综合水平呈现北高南低、北部和南部区域内部重点镇高于一般镇的等级梯度分异格局.（2）设施农用地、园地和设施耕地等集约利用程度较高的农用地比例很大,集中分布在村镇和道路附近,生产便利性和成本是其空间分异的主要影响因素;（3）各类土地破碎化严重,集聚度和规模化程度低,亟需通过土地综合整治,重构村庄空间体系,充分发挥循环经济和农用地多功能性的优势,优化农业产业间及其与非农用地间的用地结构和空间布局,进一步提高土地利用综合效益.     

近郊生态农业与西部生态城市建设协同发展研究

生态城市是结合了社会、经济和自然的区域综合.生态城市因其追求人与人、人与环境的高度和谐,成为21世纪城市发展的新模式.西部生态环境脆弱,环境污染严重,建设生态城市存在着种种困难.近郊生态农业具有促进生态平衡,改善生态环境;促进近郊经济发展,提高农民收入;提升城乡居民的生态文明意识的作用,城市生态建设与近郊生态农业发展都以取得生态效益、经济效益和社会效益三者相统一为目标.在近郊大力发展生态农业,能够促进生态城市建设进程.建设生态城市,也能够为生态农业发展奠定良好的基础.因此,倡导生态农业和生态城市共同建设,二者相互影响,从而实现协同发展.     

城郊型小城镇生态化发展的思考——以长沙市岳麓区雨敞坪镇为例

随着工业经济的快速发展,工业化在为我们提升经济总量,提高综合竞争力的同时,也给人类的生存和持续发展带来严重问题,如环境恶化、资源紧缺等,需要新的发展方式,对于小城镇来说,尤其是城郊型小城镇具有独特的区位优势,走生态化发展之路是其城镇化的最佳途径。本文以长沙市岳麓区雨敞坪镇为例,分析了雨敞坪镇的发展现状,指出发展中存在的问题,并提出其生态化发展的具体思路。     

近郊丘陵谷地高效农业综合开发研究

在剖析近郊丘陵谷地资源优势及利用问题的基础上，应用生态学和系统论原理及方法，以市场为导向，进行谷地资源的多目标线性规划，通过对区域系统物质循环、能量转化及经济效益的分析，提出“以鱼鸭结合为龙头，稳定果园面积，发展高效种植业”的总体规划方案，采取低产幼龄果园改良、名特优苗木繁育、池塘高产养殖和建立高效种植制度等技术措施，对谷地资源实行立体动态综合开发，建立较稳定的近郊丘陵谷地人工农业生态系统，取得显著的经济、社会和生态效益。     

Assessment of tropical suburban surface soils contamination from Jengka,Malaysia

Heavy metals in suburban soils pose both indirect and direct health risks. This study assessed the concentrations of Cr, Zn, Pb, and Cd in Jengka (Malaysia) suburban soil and estimated the human health risk. Health risk assessment (HRA) was utilized to assess non-cancer and cancer risks. The concentrations of heavy metals increased in the following order: Cd < Zn < Cr < Pb. The heavy metals were found to be divided into two components using principal component analysis (PCA), with PC1 comprising Pb and Cd and PC2 containing Zn and Cr. PC1 originates from anthropogenic sources, while PC2 is often from mixed anthropogenic and natural sources. Despite having the lowest mean concentration, Cd was enriched based on the geo-accumulation index (Igeo) and enrichment factor (EF). Average hazard index values were below the acceptable threshold (HI < 1) for dermal and inhalation pathways suggesting a low non-cancer risk. Jengka suburban soil had total lifetime cancer risk values slightly higher than the acceptable threshold (1 × 10⁻⁵). Skin contact was the most prominent contributing exposure pathway for both non-carcinogenic and carcinogenic risks. This study suggests that heavy metal bioactivity levels be used to make a plausible HRA of heavy metal pollution in suburban soils.     

Spatial and Geographical Variations of Urban, Suburban and Rural Atmospheric Concentrations of Phenols and Nitrophenols (7 pp)

Goal, Scope and Background Atmospheric sampling (gas and particles) of 5 phenols (phenol, m-cresol, p-cresol, o-cresol, pentachlorophenol) and 15 nitrophenols (3-methyl-2-nitrophenol, 3-nitrophenol, 4-methyl-2-nitrophenol, 5-methyl-2-nitrophenol, 2-methyl-3nitrophenol, 3-methyl-4-nitrophenol, 2,6-dinitrophenol, bromoxynil, 2,5-dinitrophenol, 2,6-dinitro-p-cresol, 2,4-dinitrophenol, ioxynil, DNOC, 3,4-dinitrophenol, dinoseb) on XAD-2 resin (20 gr) and glass fibre filters, respectively, were performed in 2002 by using 'Digitel DA80' high volume samplers. These measurements were undertaken in order to show spatial and geographical variations of concentrations and the role of traffic in the emissions of these compounds to the atmosphere. Methods Sampling were performed in Strasbourg (eastern France), in its vicinity (Schiltigheim) and in Erstein. Sites were chosen to be representative of urban (Strasbourg), suburban (Schiltigheim) and rural (Erstein) conditions. Field campaigns were undertaken simultaneously in urban and suburban sites during all the seasons during 4 hours at a flow rate of 60 m3.h-1, which gives a total of 240 m3 of air per sample. Period of sampling varied between 06h00 to 10h00, 11h00 to 15h00 and 18h00 to 22h00 in order to evaluate a variation of concentration during automobile traffic between urban, suburban and rural areas. Gas and particle samples were separately Soxhlet extracted for 12 h with a mixture of CH2Cl2 / n-hexane (50:50 v/v), concentrated to about 1 mL with a rotary evaporated and finally dried under nitrogen. Dry extracts were dissolved in 1 mL of CH3CN. Before analysis, extracts were sylilated by using MTBSTFA. Analysis was performed by GC/MSD in the SIM mode. Results and Discussion Partitioning of phenolic compounds between gas and particle phases seems to be mainly correlated with vapour pressure. Among phenolic compounds analysed, phenol, p-cresol, pentachlorophenol and 2.4-dinitrophenol were detected in all samples and emissions from traffic seems to be the major source for the presence of these compounds to the atmosphere. No increase of concentrations in autumn tend to confirm this hypothesis since, with the use of domestic heating in colder months, increases of PAHs concentrations were observed and these compounds are known to be emitted by all combustion processes. Pentachlorophenol is a special case since this molecule is only used as wood preservative. Its presence in all atmospheric samples, whatever the locations and the period of time is the consequence of its persistence. Conclusions and Perspectives These measurements demonstrate that phenols and nitrophenols are emitted to the atmosphere and further measurements, in order to confirm their sources, their behaviour and their potential impact to the air quality and to human health should be undertaken especially since the literature collected is relatively old. Concentrations of pentachlorophenol measured are very low and, due to its toxicity, further investigations should be undertaken. - * The basis of this peer-reviewed paper is a presentation at the 9th FECS Conference on 'Chemistry and Environment', 29 August to 1 September 2004, Bordeaux, France.     

单双号限行对郊区道路机动车尾气排放的控制效果研究

北京大型活动期间的道路车流量控制是缓解交通拥堵和削减尾气排放的重要手段。郊区道路的车型构成和行驶工况与城市道路有显著差别,研究车辆限行对郊区道路机动车尾气排放的影响是空气质量保障方案制定、控制效果评估和进行空气质量预测预报的基础。以中国人民抗日战争胜利纪念日阅兵期间郊区道路车流信息为基础,采取排放强度计算、路边污染物浓度监测和逆模式法相结合,研究了车辆限行对郊区道路机动车尾气排放的影响。结果显示:郊区道路限行期间国道、省道和县道车流量降比分别为21%、29%和24%,货运车辆降比大于客运车辆,车辆行驶速度上升;CO、NO_x、HC和PM的减排比国道分别为41%、46%、48%和76%,省道分别为43%、31%、45%和47%,县道分别为33%、27%、34%和43%。路边的NO_x浓度监测结果显示,限行期间NO_x浓度下降47%;根据现场的NO_x浓度监测数据以及气象参数,应用逆模式法计算NO_x排放强度,结果显示限行期间NO_x排放强度下降37%。     

Impact of Native Plants on Bird and Butterfly Biodiversity in Suburban Landscapes

Abstract:  Managed landscapes in which non-native ornamental plants are favored over native vegetation now dominate the United States, particularly east of the Mississippi River. We measured how landscaping with native plants affects the avian and lepidopteran communities on 6 pairs of suburban properties in southeastern Pennsylvania. One property in each pair was landscaped entirely with native plants and the other exhibited a more conventional suburban mixture of plants—a native canopy with non-native groundcover and shrubs. Vegetation sampling confirmed that total plant cover and plant diversity did not differ between treatments, but non-native plant cover was greater on the conventional sites and native plant cover was greater on the native sites. Several avian (abundance, species richness, biomass, and breeding-bird abundance) and larval lepidopteran (abundance and species richness) community parameters were measured from June 2006 to August 2006. Native properties supported significantly more caterpillars and caterpillar species and significantly greater bird abundance, diversity, species richness, biomass, and breeding pairs of native species. Of particular importance is that bird species of regional conservation concern were 8 times more abundant and significantly more diverse on native properties. In our study area, native landscaping positively influenced the avian and lepidopteran carrying capacity of suburbia and provided a mechanism for reducing biodiversity losses in human-dominated landscapes.     

广西城市近郊型地下河水中多环芳烃污染特征研究

利用气相色谱-质谱联用仪(GC-MS)对广西清水泉地下河水16种多环芳烃(PAHs)的质量浓度进行了测定,研究地下河水中PAHs的质量浓度、组成和分布,并对其进行生态风险评价,为城市近郊型地下河系统持久性污染物防治提供科学依据。结果表明,地下河水中∑PAHs质量浓度为162.13~224.99 ng/L,平均值为191.71 ng/L,PAHs以2~3环为主,占49.36%;地下河水中PAHs的质量浓度自上游至下游逐渐增大,2~3环PAHs的百分比先升高后降低;地下河水中Ba A和Bb F处于中等污染和高污染风险,应采取控制或修复措施降低污染风险,剩余PAHs除了In P在水中未检出外,均显示为低污染风险。     

城郊地区土地利用总体规划的结构设计

本文运用系统工程中的分解与协调原理，借助成都市龙泉驿区土地利用总体规划，对城郊土地利用总体规划进行结构设计，较好地达到了城郊地区土地利用总体规划的定量、定位与定时的统一，宏观控制与微观操作的统一．