改革开放以来北京市人口空间分布的变动特征——基于1982-2010年四次人口普查资料的分析

本文使用了1982年、1990年、2000年和2010年的北京市第三次、第四次、第五次和第六次共四次人口普查资料的相关数据,综合利用人口重心研究方法和标准离差椭圆分析方法,借助于Arcgis软件分析工具,分析了北京市人口空间分布的集中和离散的变化趋势,揭示了改革开放以来北京市人口空间分布的基本演变态势。研究结论表明,近30年间,北京市人口空间分布的总体格局呈现为人口增长速度提高、人口规模总量不断膨胀的基本态势,城市功能拓展区和城市发展新区的人口增长速度领先,全市人口重心位于城市中心区的北部位置,位移距离变化较小,基本保持稳定;北京全市域人口密度由内到外呈现较为显著的阶梯状递减特征,中心城区人口密度与近郊区人口密度梯度差异逐渐变小,近郊区与远郊区的人口密度的梯度差异逐渐扩大,以中心城区和近郊区分布为主的首都功能核心区和城市功能拓展区人口集聚趋势依然明显,反映了北京市人口空间分布结构具有较强的稳定性特点;北京市人口标准离差椭圆长短轴均呈缩短趋势,长短轴之比亦呈变小趋势,反映了在北京市人口规模整体扩张的基本态势上,北京市人口空间分布呈现出更强烈的向心极化趋势和同心圆集聚趋势。总之,北京市仍然表现为人口增量型的城市化发展阶段,相对稳定的人口重心变化和较小的标准离差椭圆变化表明了北京市人口增加趋势呈现出城市化中后期趋于相对稳定的发展阶段,质量型城市化将进一步成为北京市未来城镇化过程中的主要挑战。     

上海市人口分布变动的空间特征分析

空间自相关分析是一种空间统计的方法。可以揭示区域变量的空间结构形态。通过对2000-2003年期间上海市乡镇人口密度变化率的空间相关性分析，发现上海市近几年人口分布空间变动格局表现为以中心城区为中心的环状分布模式，中心城区和远郊区人口密度变化小。人口增长缓慢，而近郊区人口密度变化大，人口增长迅速。全市人口密度变化率存在着显著的空间集聚现象。四种类型的空间关联在空间分布上具有明显的规律性。研究结果表明，目前上海市人口郊区化趋势明显。高人口密度区域在不断向外扩张，人口分布与经济、交通等社会发展因素的关系日益密切。这些研究结果说明利用空间自相关统计方法能够扩展和加强对人口分布空间模式的研究．从而为经济总体布局和城市化建设提供辅助参考作用。     

20世纪90年代西安市人口空间变化与郊区化动向

20世纪90年代以来，随着社会经济的快速发展，西安市人口的空间分布发生了很大变化。运用第四次和第五次人口普查数据，通过与20世纪80年代情况的对比。剖析20世纪90年代以来西安市人口数量、人口密度在西安不同地域层次上的分布及变化特征；针对人口变化强度较大的市三环线以内，将其划分为十大功能区段，进一步分析论证西安市中心区人口的外迁动向。研究证明：西安市在1990—2000年间开始进入郊区化过程。且处于相对郊区化阶段；市中心区人口主要迁到内圈（区段Ⅱ）及中圈的高新技术开发区（区段Ⅵ）、文教区（区段Ⅴ）和经济技术开发区（区段Ⅺ）。     

转型期南京市制造业郊区化及区位选择

城市郊区化是城市发展的重要阶段，我国城市郊区化有着深层的制度和经济背景。以南京为例，重点研究了制造业郊区化问题。首先分析了南京制造业企业空间聚散格局及郊区化程度，而后建立一个在我国经济和制度转型背景下制造业郊区化的理论框架，就政府行为和企业行为转型对制造业郊区化影响进行了分析，并导出相关要素，采用计量模型对要素检验进行，对其作用方向和强度进行分析。研究发现，南京制造业已进入明显的郊区化进程，城市近郊区的一些重点街镇和中心区外缘的少部分街道是制造业郊区化集聚的主要方向。并认为20世纪90年代开始实施的“退二进三”城市产业结构调整、土地有偿使用、郊区对外交通条件的改善、开发区和工业园区的建设是制造业郊区化的重要影响因素。     

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运用空间自相关的全域指标和局域指标，分析1990年和2000年上海市域及中心城区两个年份的人口密度的Moran's I和Getis's G值。结果表明：从市域的尺度上看，10年间，人口集聚增强，即城市高密度集聚、农村低密度集聚，中心城区及其内部出现的人口密度相对分散的趋势只是表现在城市内部，而市域内城市与农村之间的差异仍在不断扩大，表现为一种从农村向城市的向心型城市化过程，而且城市化还处于不断上升的阶段。从中心城区的尺度看，10年间，中心城区人口密度不断降低，城区核心人口绝对量持续减少，城区外缘绝对量持续增加，上海市城区具有明显的郊区化特点，空间上表现出一种离心型城市化的特点。研究结果的可借鉴性表明空间自相关的统计分析能更好地揭示出人口的分布模式、人口集聚及其变化的热点和内在机制，对于人口的合理布局方案、城市化政策制定等政府宏观决策具有意义。     

世博后上海人口分布新态势

世博后上海经济社会发展转型、现代化城市基础设施和全面调整优化空间载体战略布局等因素将对上海人口分布产生重要影响.该文利用灰色理论模型对人口分布变动进行预测,结果表明:2010-2020年期间,上海市人口继续向郊区集聚,近郊区是人口集聚和流动的最显著区域,同时远郊区常住人口集聚的增长速度开始超过近郊区,成为人口迁移和流动的主要区域.今后一段时期内近郊区和远郊区为上海产业发展和人口布局调整提供空间,近郊区和远郊区的新城镇将成为重点建设区域,上海将加快形成城乡一体化发展的新格局.建议:加强人口发展战略和规划研究,解决土地规划、产业规划和人口规划的问题,统筹考虑土地、产业、人口之间的协调发展;实施城市人口发展功能区战略,引导人口有序流动和迁移,使上海城市人口空间布局与城市形态、区域功能和资源环境协调发展;加强流动人口均等化服务,建立健全流动人口基本公共服务均等化投入保障机制.     

中国大城市郊区化对城市可持续发展的影响分析

进入20世纪80年代以来，中国经济在改革开放的促进下飞速发展，城市化水平大大提高。随着城市的发展和人民生活水平的提高。以及城市产业结构的调整，我国一些大城市一部分工业尤其是污染扰民工业开始从中心区向郊区搬迁，大城市工业进入郊区化发展阶段。随着住房制度的改革，大城市中许多工薪阶层开始住进郊区的单位分房或自购房。人口郊区化及随之而来的商业郊区化也开始显现。我国大城市郊区化是中国城市发展过程中的一种重要现象。城市郊区化对城市发展产生了深远影响。本文以北京、上海、广州、杭州、苏州、沈阳、大连等大城市为例，概括了当前我国大城市郊区化的现状特点，指出了郊区化对城市可持续发展的影响，提出了相应的管理对策，为城市管理部门提供参考。     

长江三角洲地区人口空间演变特征及动力机制

研究区域人口空间演变,可揭示区域人口空间分布的规律性,对于制定合理的人口发展政策,促进区域的可持续发展,均具有重要意义。根据1982、1990、2000年人口普查资料,结合长江三角洲地区各市历年统计年鉴,先对本地区的人口分布空间格局进行了分析,得出各地市人口数量差异巨大、人口密度北高南低、沿交通轴线人口集中分布的特点,然后对20世纪80年代以来人口分布的动态变化特征、规律做了较细致探讨,得出各地区人口增幅存在较大差异、人口密度增长总体放缓、人口分布先集中后分散、人口重心由东北向西南移动等演变特征。并结合影响区域人口空间分布的外部因子进行解释,认为经济因素、城市地位与功能、政策因素以及信息交通等因素是造成本区人口空间结构发生巨大变化的原因。     

1982～2010年湖北省人口分布格局变迁及其影响因素

以人口普查数据为基础,采用空间分析技术,对1982~2010年湖北省人口分布的变迁及原因进行研究。结果表明:(1)湖北省人口分布具有显著的空间差异:区域尺度上,人口分布由东向西梯度递减,且梯度差异不断扩大;地市尺度上,武汉市始终是人口密度最高的地区,神农架、恩施、十堰、宜昌始终是人口密度最低的地区;县级尺度上,人口两极分化明显;省域尺度上,人口密度高值区长期呈三足鼎立的态势,人口重心始终位于几何中心以东,并不断向东迁移;(2)湖北省人口格局形成的原因是多方面的:自然地理差异是奠定湖北人口分布格局的决定因子;社会经济发展对湖北人口分布在自然基础上进行再塑造;区域发展战略对湖北人口分布的变迁起着重要导向作用;开发历史也在一定程度上影响了人口分布的布局。     

武汉城市圈人口分布的时空格局

基于1990~2010年人口统计数据，结合数理统计分析方法和GIS空间分析方法，探讨了武汉城市圈人口空间分布的时空格局分异规律，得出以下结论：（1）圈域人口规模持续稳步增长，可划分为1990~1999年剧增阶段、1999~2006年滞涨阶段和2006~2010年稳步增长3个阶段；（2）圈域人口格局表现为东西向的交通廊道（宜黄 黄黄 黄小高速）指向且不断得到强化；（3）人口密度的空间变异系数先升后降，圈域人口分布的空间差异先扩大后缩小，但空间差异的绝对水平即空间异质性特征仍较为突出；（4）人口分布的动态变化格局表现为“圈层式”空间分异，圈域人口分布的主要方向为西北 东南向，且在进一步的往东南方向集聚；（5）圈域人口格局是自然地理条件、区域公共政策、社会经济发展和交通运输条件共同作用的结果     

WSSD 2002, Latin America and Brazil: Biodiversity and Indigenous People

Latin America comprehends notable variations in terms of natural environment, availability of natural resources, living standards, and demographic patterns. Latin America is a mosaic of cultures, post- and pre-Columbian. The rich variety of life forms discovered and described by chroniclers and traveling naturalists in the Neotropics contributed to the proposal, in mid-XVIIIth century, of a new system of classification and a scientific code of nomenclature for all organisms. Biodiversity was, for many centuries, a source of resources to be exploited in natura. In scientific circles, its inventory became the domain of taxonomists. But modern technology showed how important the miriad of life forms really are as sources of chemical molecules to be engineered as drugs and reassembled as novel manufactured products. We are on the brink of a new agricultural and medical revolution, thanks to the techniques of genetic engineering, which will lead eventually to the elimination of hunger and malnutrition.In this essay, the Brazilian environmental and social heterogeneity will serve as an example to illustrate some key points, which have influenced sustainability policies. The Amazon deforestation and indigenous knowledge (IK), subjects often associated with areas of high biodiversity, are usually the focus of environmental debates. The importance of IK in integrating development, reducing poverty and sustainability are considered together with the intellectual property rights of native populations.In the World Summit on Sustainable Development (WSSD) Implementation Plan, a few paragraphs were dedicated to Latin America, because of the pre-existing Action Platform on the Road to Johannesburg 2002, approved in Rio de Janeiro in October 2001. This paper calls attention to the need to draw up specific environmental policies for a region which shows an extremely high cultural and biological diversity, associated with a high availability of forests and water, among other resources.     

Household water in rural asia: a case study of the construction of a piped water system in Bangui,Ilocos Norte,Philippines

In early 1980 an extension agent was assigned to the rural municipality of Bangui, Ilocos Norte, Philippines to work on development projects – in particular the improvement of the supply of safe water for drinking and sanitation. After many months of visiting spring sites and meeting with community leaders, a small part of the municipality was selected to build a gravity fed piped water system. Although the system took many months to plan, identify funding and construct, the 600 community members were ultimately rewarded with house to house connections that enabled them to achieve per capita water consumption levels above the minimum levels recommended by the World Health Organization. Of course, money was critical to ensure the project’s success, but many other factors played an equally critical role. For instance, without the active participation of the community and the unwavering support of the community leadership the project would not have survived the initial planning stage. Also, the extension agent played a critical role by acting as a conduit between funding agencies, the Bureau of Public Works and the community. The primary lesson to be learned from this experience is that the success of rural development projects is largely driven by the synergy between the community, technical support, financial support, and agents of change such as extension agents. If any of these ingredients had been lacking, the project result would likely have been far different.     

Human exposure to polybrominated diphenyl ethers (PBDE), as evidenced by data from a duplicate diet study, indoor air, house dust, and biomonitoring in Germany

Polybrominated diphenyl ethers (PBDE) are used as flame retardants in a wide variety of products. As part of the Integrated Exposure Assessment Survey (INES), this study aimed to characterize the exposure of an adult German population using duplicate diet samples, which were collected daily over seven consecutive days, and indoor air and house dust measurements. Our study population consisted of 27 female and 23 male healthy subjects, aged 14–60 years, all of whom resided in 34 homes in southern Bavaria. In these 34 residences the air was sampled using glass fiber filters and polyurethane foams and the dust was collected from used vacuum cleaner bags.The median (95th percentile) daily dietary intake of six Tetra- to HeptaBDE congeners was 1.2 ng/kg b.w. (3.3 ng/kg b.w.) or 67.8 ng/day (208 ng/day) (calculated from the 7-day median values of each study subject). Concentrations in indoor air and dust (cumulative Tri- to DecaBDE congener readings) ranged from 8.2 to 477 pg/m³ (median: 37.8 pg/m³) and 36.6 to 1580 ng/g (median: 386 ng/g), respectively. For some congeners, we identified a significant correlation between air and dust levels.The median (95th percentile) blood concentration of total Tetra- to HexaBDE congener readings was 5.6 (13.2) ng/g lipid. No significant sex differences were observed, but higher blood concentrations were found in younger participants. Using a simplified toxicokinetic model to predict the body burden from exposure doses led to results that were of the same order of magnitude as the measured blood concentrations.Based on these measurements and given our exposure assumptions, we estimated for the total tetra- to heptabrominated congener count an average (high) comprehensive total daily intake of 1.2 ng/kg b.w. (2.5 ng/kg b.w.). Overall, our results suggest that dietary exposure is the dominant intake pathway at least in our study population, responsible for 97% (average intake) and 95% (high intake) of the total intake of an adult population.     

A new general mechanistic river model for radionuclides from single pulse fallouts which can be run by readily accessible driving variables

This paper presents a new general, process-based river model for substances such as radionuclides from single pulse fallouts. The new model has been critically tested using data from 13 European rivers contaminated by radiocesium from the Chernobyl accident. This modelling approach gives radionuclide concentrations in water (total, dissolved and particulate phases; and also concentrations in sediments and fish, but the latter aspects are not discussed in this paper) at defined river sites. The model is based on processes in the upstream river stretch and in the upstream catchment area. The catchment area is differentiated into inflow ( approximately dry land) areas and outflow ( approximately wetland) areas. The model also accounts for time-dependent fixation of substances in the catchment. The catchment area sub-model is based on a previous catchment model, which has been tested with very good results for radiocesium, radiostrontium and Ca-concentrations (from liming operations). The new river model is simple to apply in practice since all driving variables may be readily accessed from maps and standard monitoring programs. The driving variables are: latitude, altitude, continentality, catchment area, mean annual precipitation, soil type (percentages or organic and sandy soils), fallout and month of fallout. Modelled values have been compared to independent empirical data from 10 rivers sites (91 data on radiocesium in water) covering a wide domain (catchment areas from 4000 to 180 000 km(2), precipitation from 500 to 960 mm/yr and fallout from 1700 to 660 000 Bq/m(2)). The new model predicts very well--when modelled values are compared to empirical data, the slope is perfect (1.0) and the r(2)-value is 0.90. This is good giving the fact that there are also uncertainties in the empirical data, which set a limit to the achieved predictive power, as expressed by the r(2)-value.     

Narratives,Rhetorical Genres,and Environmental Conflict: Responses to Schwarze's “Environmental Melodrama”

The appearance of Steven Schwarze's essay, “Environmental Melodrama” (Schwarze, 2006) as the lead article in a recent issue of The Quarterly Journal of Speech marks an important moment of recognition for environmental communication scholarship. Schwarze's essay demonstrates how studies of environmental rhetoric can contribute to rhetorical theory more generally, while addressing practical questions regarding the rhetorical aspects of environmental conflict. The contributors to this forum respond to Schwarze's arguments, drawing in part upon their own case studies of rhetorical action and narrative in environmental conflict.     

The influence of hot particle contamination on Sr and Cs transfers to milk and on time-integrated ingestion doses

Most models for transfers of radionuclides through the food chain typically assume that the radioactivity is initially deposited in chemically available forms. It is known, however, that releases of radionuclides in the form of hot particles may significantly influence their environmental transfers and uptake to the food chain. This study presents models for time changes in ⁹⁰Sr and ¹³⁷Cs in milk which incorporate hot particle contamination using observed rates of hot particle dissolution following the Chernobyl accident. A general equation is presented for the influence of hot particles on overall ingestion doses. As expected from previous work, fallout of hot particles significantly influences time changes in radionuclide activity concentrations in foodstuffs. It is also shown that incorporation of radionuclides in hot particles influences time-integrated ingestion doses. For a situation in which a large proportion (90–100%) of fallout is in slowly dissolving hot particles, time-integrated ingestion doses from ⁹⁰Sr and ¹³⁷Cs are reduced by a factor of approximately two compared to the case where all radioactivity is deposited in bioavailable forms. However, the influence of rapidly dissolving hot particles on time-integrated ingestion doses is relatively minor. Remaining significant uncertainties in dose estimates are discussed.     

Communities of hydrobionts developing at the water-rock interface in Lake Baikal

Development of benthic communities on rocks from the interdisciplinary test site near Cape Berezovyi (southern Baikal) is analyzed. Rock plates were placed on the bottom in the shallow-water zone of Baikal for six months, and a community consisting of microorganisms, microphytobenthos, and meiobenthos developed on them. The development and activity of hydrobionts depended on the chemical composition and structure of the rock. Marble and granite plates were populated by them more selectively than amphibolite plates. It is supposed that the biota plays an important role in destruction of rocks in the shallow-water zone of Baikal.     

21世纪我国国土资源可持续利用的形势及战略措施

本文分析了我国国土资源可持续利用的形势,指出了国土资源在经济发展中的地位和作用,提出了国土资源可持续利用的任务和战略措施。     

Radionuclides in terrestrial ecosystems of the zone of Kyshtym accident in the Urals

It was shown that along the Eastern Ural Radioactive Trace central axis, about 100 km in length, decrease of the ⁹⁰Sr and ¹³⁷Cs deposition densities in soil samples may be described as an exponential function. At the western and eastern periphery of the trace, ⁹⁰Sr contents in soils approached to the background level due to global fallout. ⁹⁰Sr and ¹³⁷Cs concentrations in seeds of some herbaceous plants have been determined. The radionuclide concentrations and the resulting dose loads upon plant seeds showed an excess over the background level of about two or three orders of magnitude.