基于因素分析的城市土地集约利用比较研究

构建了一套城市土地集约利用评价的指标体系，利用多元统计分析中的因素分析法，对我国特大城市土地集约利用进行了综合评价，并对我国城市土地集约利用水平进行了比较分析。     

大城市郊区农村居民点整理效果分析——基于典型案例的比较研究

大城市郊区作为农村居民点整理的典型区域之一,如何评价其整理效果具有重要意义。分析大城市郊区农村居民点整理影响机理,构建整理效果评价指标体系,使用规划资料、调查资料和统计资料,对比研究天津市津南区、成都市双流县和上海市金山区典型项目的整理效果。结果表明:①综合评价结果由高到低依次为金山项目、津南项目和双流项目;②整理后农民居住条件均明显改善,生活成本普遍提高,社会保障有所增加,对收入和就业影响不明显;③整理可有效改善土地资源利用状况,农村建设用地节余58%～82%,人均建设用地下降31%～84%,新增耕地超过30%;④3个项目政府的投资风险均较高,项目可持续性有待商榷;农户的拆迁补偿标准和重置新房成本存在较大差异,并导致金山项目的农户搬迁能力高于津南项目和双流项目。研究结论:大城市郊区总体适宜开展农村居民点整理。整理效果呈现差异受政府财政能力与农民收入水平相对大小的影响。     

重庆都市圈可持续发展面临的主要生态环境问题与对策

对重庆都市圈生态环境问题进行了详细的分析;结合都市圈可持续发展和三峡水库安全运行的需求,提出了加大都市圈生态环境建设力度和绿地景观整治工程,优化产业结构与布局,扶持循环经济和生态环保产业发展,控制主城区规模、积极发展周边卫星城市,增加环保投入、加强重点环保基础设施建设、实施"净空"和"碧水"工程,建立都市圈生态环境信息管理系统和预警系统、实施都市圈生态系统管理等8条治理途径与措施。     

中国大都市区域的城乡协调发展研究 --以浙江省宁波市为例

工业化与城市化是伴生的,工业化对城市化有促进作用,工业化的发展阶段不同,城市的规模和结构也不一样,城乡关系也会因为工业化的演进而演变。随着城市的扩张,城乡之间的关系将从二元结构向城乡转型直至城乡融合阶段演变。在不同的阶段,要素流在城乡之间呈现不同的流向,对城乡的发展也起着不同的作用,同时还会影响到产业的地域分布。本文从处于工业化中期阶段的宁波市特殊的区位和区域环境出发,分析了宁波市的城乡发展格局,指出宁波市城乡之间存在着分工不明确、产业竞争严重等问题,尤其是平面化的城镇体系严重影响其中心城市功能的发挥。针对存在的问题,文中提出将宁波市建设成为长三角最大的后勤中心、提升中心城区的功能和产业结构、农村城镇之间实行网络化发展、以及用工业化理念来经营农业等对策和措施。     

Groundwater characterization in major industrial and residential locations of Lagos metropolis

This study investigated the quality of groundwater collected from two industrial and residential locations, each within the Lagos metropolis. Prescribed standard procedures of the American Public Health Association (APHA) were used to measure the physicochemical parameters of each of the groundwater samples, which include pH, electrical conductivity (EC), dissolved oxygen, total dissolved solids (TDS), biological oxygen demand, chemical oxygen demand; the anions chloride (Cl^?), nitrate (NO₃^?), sulfate (SO₄^?), and phosphate (PO₄^?); and heavy metals copper (Cu), zinc (Zn), lead (Pb), manganese (Mn), iron (Fe), cobalt (Co), cadmium (Cd), and chromium (Cr). Based on the laboratory analysis, the physicochemical parameters that were measured were within the permissible ranges specified by the World Health Organization and the Nigerian Standard for Drinking Water Quality Standards Organization of Nigeria (SON), except for pH, TDS, EC, Pb, Mn, and Fe for groundwater samples from the industrial locations and for pH, Pb, Mn, and Fe for residential locations. The elevated concentrations of TDS and EC reported for groundwater samples from industrial locations were attributed to the heavy discharge of effluents from nearby industrial treatment plants as well as the dissolution of ionic heavy metals from industrial activities involving the use of heavy machines. Statistical analysis using Pearson's correlation revealed the physicochemical parameters to be moderately and strongly correlated with one another at either p < .05 or < .01. In conclusion, groundwater samples from residential locations are more suitable for drinking than those from industrial locations.     

长株潭都市区湘江生态经济带建设

都市区作为高密度的人类聚集地,人口与生态环境的矛盾日益突出。都市区生态经济建设显得尤为重要。长株潭都市区3座城市呈“品”字型分布,湘江一水串起3市,建设集旅游观光、生态绿化、科技园区、住宅区和重点小城镇于一体的带状生态经济综合体,即湘江生态经济带,对整个长株潭都市区生态经济建设发挥重要作用。     

Genotype × environment interactions: survival performance of six internationally sourced provenances of <Emphasis Type="Italic">Azadirachta indica</Emphasis> A. Juss in a degraded land in Kano,Nigeria

In order to prevent ‘an impending neem failure’, from the incidence of the twin problems of the neem scale insect infestations and neem dieback, six authenticated provenances (Allahabad, Karnataka, Jodphur, Madinipur, Mukkambu and Annur), from the natural range of the species in India, were collected and appraised for survival in a degraded land in Kano, Nigeria. Established in a completely randomised block design with four replications, the trial was conducted with a view to restrengthening and/or replacing the already weakened Local Land Race of the species in the study area. There was a statistically significant difference in the survival of the seven provenances. The established differences are between Allahabad 83% (6.40 SEM), Mukkambu 83% (6.40 SEM), Annur 76% (4.90 SEM), Jodphur 63% (15.09 SEM) and Madinipur 56% (6.73 SEM), on the one hand, and Karnataka 17% (1.91SEM) and the Local Land Race, with 13% (0.13 SEM), on the other hand. The research recommends Allahabad and Mukkambu 83% (6.40 SEM) based on this outstanding performance.     

北京市人口动态模拟与政策分析

随着城市化进程的加快,我国城市规模不断膨胀,超过1 000万的超大城市不断涌现,城市人口规模过大、增长过快以及带来的城市问题引起社会各界的关注。北京作为一个人口超过2 000万的超大城市,不仅具有超大城市的一般特征,而且具有首都所在城市的特点。本文在厘清北京人口增长机制的基础上,采用系统动力学方法,通过政策模拟,考察不同政策导向对未来北京市人口增长趋势的影响,得到以下结论:1如果保持当前的经济增长速度,并按当前的生产技术水平以及产业结构变化趋势发展,未来北京人口规模将持续快速增长,到2030年将突破3 000万人,2050年将接近5 000万人,城市面临巨大的人口压力。2单纯通过产业结构升级对调控人口作用有限。3适当放缓经济增长速度以及大力提高劳动生产率可以有效控制人口的快速增长,挤出大量的低端劳动力,人口调控效果明显。4户籍制度的适度放开在一定程度上减少了外来人口规模,但对人口总量的减少并没有起到作用。5与单纯采用一种政策调整相比,多种调控政策并举调控人口的效果更佳。由此得到以下几点启示:首先,每个城市都应该有自己的功能定位,决不能搞"大而全"和千城一面,尤其不能将城市经济增长速度和总量作为城市发展的主要目标甚至唯一目标,不顾后果和不择手段地追求GDP。否则城市人口规模的无序扩大就很难避免,也很难治理。对于北京而言,发挥其政治、文化、国际交往以及科技创新中心的首都功能,大力发展现代服务业,提高劳动生产率,优化产业结构才有利于人口的有序发展。另外,政府在人口调控方面必须有所作为,但也不能对人口调控进行大包大揽,取代市场。政府要顺应经济和社会发展的规律,顺势而为,出台相应的系列综合性调控政策。只有这样,才能对人口调控起到更好的效果。     

Characteristics of air pollution by polychlorinated dibenzo-p-dioxins and dibenzofurans in the typical industrial areas of Tangshan City, China

The ambient air in vicinity of different industrial sources for PCDD/PCDFs was sampled by TSP/PM10 active samplers and passive PUF disk samplers in Tangshan City, a metropolis containing clusters of various industrial plants. The TEQ concentrations of PCDD/PCDFs ranged from 44.2 to 394.1 fg I-TEQ/m3 with an average of 169.9 fg I-TEQ/m3. 2,3,4,7,8-PeCDF was the dominant contributor to PTEQ, contributing 41% (12% to 55%), while 1,2,3,4,6,7,8-HpCDF, OCDD and OCDF were the major congeners for the total concentrations. The ratios of PPCDF/PPCDD reached 2.54 on average, suggesting that de novo synthesis in thermal processes played an important role to the airborne pollution of PCDD/PCDFs. The similarities congener profiles indicated that TSP and PM10 active sampling methods are comparable for the determination of the PCDD/PCDFs in ambient air, and the ratios of concentrations determined by the two methods suggested that the PCDD/PCDFs tended to stay in fine particles. It was found that 2,3,7,8-TCDF and OCDD were the dominating congeners in the passive PUF disks samples. Through principal components analysis, the coke industry was suggested to be a relatively high potential emission source for PCDD/PCDFs in the ambient air of Tangshan, which was possibly formed by de novo synthesis mechanism. In this study, the atmospheric impacts to the environment from di erent industrial sources could be ranked as follows (from high to low): coking, iron sintering, steel making, power generation and chlorinate alkali chemical production industries.     

Spatial distribution of particulate matter (PM10) in Warri metropolis,Nigeria

This study examined the spatial distribution of particulate air pollution in the Warri metropolis. This was done to ascertain the differences between the distribution of particulate matter (PM10) in the urban area and the surrounding rural areas. To achieve this, the study generated data from field measurement of PM10 levels for the year 2003. Analysis of variance, the U-test, and simple regression statistical techniques were used to analyze the data. The major finding of the study was that the Warri metropolitan area is polluted with PM10 levels of over 126 μg/m³, which is 81% over the 70 μg/m³ threshold of the World Health Organization. However the built-up area of the Warri metropolis is 150% more polluted with PM10 particulates than the surrounding rural areas. While the traffic-clogged area of Enerhen, Jakpa, Deco, and Estate Junctions are the most polluted areas with levels of 151 μg/m³, traditional areas had the lowest levels of 128 μg/m³. The daily distribution of PM10 showed that Mondays were the most polluted days with levels of 145 μg/m³ and Fridays were the least polluted days with levels of 141.5 μg/m³ in the built-up area, whereas in the rural area Wednesdays were the most polluted days with levels of 57.1 μg/m³ and Sundays were the least polluted days with levels of 53.5 μg/m³. Mondays generally recorded the highest PM10 values because of the large amount of industrial operation, heavy vehicular traffic in the peak period, and increased commercial activities. The study also showed significant variation in the level of PM10 particulates within the urban areas of the Warri metropolis with a calculated F-value (3.29), which is greater than the critical F-value of 3.14 at the 0.05 significance level. It is therefore recommended that urban environmental management policy should be vigorously pursued to curb the adverse consequences of increased PM10 levels in urban areas of the Warri metropolis.