Waste Disposal and Groundwater Management

A bout ONE THIRD of the population of the UK depends on groundwater, which is pumped mainly from the Cretaceous Chalk limestone and the Permo-Trias Bunter Sandstone, for their domestic supply. The recharge areas of both aquifers correspond broadly with areas of high population density and substantial industrial activity. The disposal of solid and liquid wastes which are generated by this large population has caused local contamination of groundwater, and there is evidence of trace concentrations of a large range of man-made organic substances in public supplies. Although total prevention of groundwater pollution is not feasible, it is increasingly evident that groundwater resources and quality management must involve improved waste-disposal management. This paper reviews the main threats, the ways in which the hazards and the resources should be monitored, and legislative changes which are desirable. The problems in the interpretation of data and the models used for prediction are also discussed.     

The built environment and health: Impacts of pedestrian-friendly designs on air pollution exposure

In the wake of the growing popularity of pedestrian-oriented community designs, it is timely to assess potential risk trade-offs of such urban planning strategies. Pedestrian-friendly designs are currently being called for and implemented in the US to tackle in particular problems associated with insufficient physical activity in the population. Unintended consequences may emerge, however, especially due to potential increases in the inhalation of pollutants as the population walking or cycling in polluted environments increases. A risk assessment of such built environment transformations was undertaken to evaluate quantitatively the competing risks and benefits of community design changes in active travel. A simulation model, built incorporating research from the fields of transportation, environmental sciences and exposure analysis, is applied to a case study area that undergoes hypothetical urban transformations. We find that the simulated population experiences roughly the same number of days in a year with decreases as number of days with increases in energy expenditure or inhalation of pollutants. In the 5% of days with greatest shifts, PM₁₀ inhalation was shown to increase by 175% or more, while the 5% of days of greatest decreases exhibited reductions of 45% or more (with similar results for ozone). Of particular concern, some individuals are shown to double their intake of the pollutants on high pollution days. However, uncertainty in the estimates is high. In particular, interpretations are very different according to the approach used to characterize year-long activity patterns. This innovative risk assessment uncovers critical gaps in the literature that must be further researched to allow essential comprehensive analyses of planning decisions.     

The effect of basic employment and regional factors on net migration: A study for Washington state

Relationships between net migration and basic employment, income, and regional urbanization are examined using 1960–70 census data for the state of Washington. Regression analysis indicates that changes in employment in agriculture, forestry, fishing and mining and in manufacturing have a direct effect on the rate of net migration. Change in median family income is also directly related to net migration but the effect is not as strong as that of employment. Location by region has a substantial impact on net population shifts with net inflows attributable to the urbanization which occurred in western Washington from 1960 to 1970. The employment, income, and regional effects are clarified by explicitly recognizing rapid growth in educational, governmental and retirement activity and recent large increases in basic employment which occurred in two small groups of counties. Overall, the results indicate that while the rate of net migration is responsive to changes in basic employment and family income, it is also important to recognize regional factors such as urbanization.A special note of appreciation is expressed to Mr. Sharif Masud who developed background data used in the analysis. Work was conducted under Regional Project W-118 of the Agricultural Research Center, Washington State University.     

Shaken,shrinking, hot,impoverished and informal: Emerging research agendas in planning

This is the second of two special issues in Progress in Planning exploring emerging research agendas in planning. It brings together scholars from diverse schools working on new areas of research and application in urban design and planning. Emergent research agendas include both novel areas of research and important shifts in the direction of a research area. The challenge for planning schools is to reflect critically on these changes and develop long-term research agendas that can better position our field in society and academia, and provide a basis from which to assess our academic programmes. The chapters in this issue display the different scales and fields of planning, including planning for: disaster recovery; climate change, especially opportunities for mitigation; shrinking cities in the First World; and rapidly urbanising informal and impoverished cities in the global South. At the same time, the chapters identify research areas that respond to major social and environmental changes. Olshansky and Chang highlight the increasing losses from catastrophic disasters, and address the need for disaster recovery planning. Wheeler, Randolph and London focus on climate change, and, noting the urgency of action now, their research agenda emphasises opportunities for planners to develop research and policies to reduce greenhouse gas emissions. Hollander, Pallagst, Schwarz and Popper look at increasing economic and population trends in many First World cities that result in city ‘shrinkage’. They present new opportunities for improving cities’ green space networks and natural features, and for research. The trebling of urban population in African cities by 2050, in conditions of poverty and informality, is the major trend driving Parnell, Pietriese and Watson's chapter. They present an agenda for new planning theories and for supporting empirical research to address the actual conditions of African cities.     

Accessibility at the household level using the Structural Accessibility Layer: A forecast of potential future travel behaviour based on self-selection of residential location

The current paper analysis the differences in accessibility categories at the household level and by lifecycle changes by using the Structural Accessibility Layer. Results are evaluated from spatial, numerical and qualitative perspectives. Main findings show differences in residential preference by a single-person household, couple without children and households with children for different potential accessibility categories. This paper provides evidence that external factors influence the population to move from public transport into car-based mobility. Finally, we observe areas categorized as suitable for both walking and public transport mobility presenting low population density and residential development of those areas is suggested.     

Population migration and economic restructuring in the United States

"This article demonstrates that sectoral employment shifts associated with the migration pattern changes of the 1970s are very different than those for the period 1955-60 to 1965-70. Changing competitiveness for jobs in manufacturing and other traditional basic sectors of the economy cannot account for the greatly accelerated levels of core-periphery net outflow that have been the dominant characteristic of interstate movement during the 1970s and 1980s. Instead, an interconnected set of activities that includes government, services, trade, and construction is associated with the broadscale shifts in the geographic pattern of the United States' population. The causal linkage from migration to employment change assumed heightened importance during the 1970s."     

HOW FUNCTIONAL ARE ECONOMIC AREAS? TESTS FOR INTRA-REGIONAL SPATIAL ASSOCIATION USING SPATIAL DATA ANALYSIS

ABSTRACT Spatial associations within eight Southeastern Functional Economic Areas were investigated using three spatial data analysis techniques (Moran's L. G₂(d) statistic and local Moran) and 1980 to 1990 population change at the country and census tract levels. Core hinterland relationships in EEAs were categorized as spread through growth, spread through decentralization, backwards or independent, based on intra regional patterns of spatial association. Findings indicate that all four of the spread backwash typologies were evident among the eight economic regions. Yet, spatial association with the core (spread or backwash) generally was limited to hinterland areas at the core's range. Spatial dependence between core and hinterland areas declined with distance from the economic region's core area. For many rural locations, changes in economic activity are independent of economic development experiences in nearby locations.     

Economic growth and urbanization: a study of Japan

In Japan economic growth and urbanization have occured within a dualistic framework in which modern (imported) and traditional (indigenous) elements coexist, and their interaction has essentially determined the pattern of industrialization. Japan's economic growth has influenced and been influenced by the shifts of population from primary to nonprimary activities and from traditional nonprimary to modern nonprimary activities. By simulating with a computable general equilibrium model calibrated with 1960 data, insight into this process is provided. This kind of model analyzes urbanization and industrialization by examining the mobility of factors of production as a response to various rates of return. The mobility described is primarily intersectoral but a certain share of the laborers who shift from primary to nonprimary is assumed to stay within the rural areas. The size of this share is a function of agricultural and various nonagricultural wage rates. The model used is described and the results of various dynamic sensitivity analyses are reported. The model is a 6-sector computable general equilibrium model, similar to the model by Karlstrom. Only the distinctly different specifications are described here. These include: sector divisions and use of vintage capital in some sectors; macro closure; wage determination; investment determination; migration determination; and import determination. 4 lessons can be learned from the set of experiments presented here. The inclusion of spatial aspects of population movements into the model offers insight into the different sectoral developments, but for macroeconomic effects a careful inclusion of spatially differentiated social capital becomes important. Expanded investment in either nonagricultural or agricultural sectors increases migration with the latter lagging behind the former. The share of laborers remaining in rural areas who have left agricultural employment goes up monotonically in the urban modern sector (HMIV) and urban traditional sector (HTIV) runs and goes down in the agricultural sector (HAIV) run until lower agricultural wages stimulate urban investment. High urban modern wages depress both intersectoral shifts and the share of nonmovers. If the social capital cost needs in urban areas are higher than in rural areas for any job shifter, a larger number of nonmoving shifters (those who change jobs without moving) means a higher potential in the medium run. Economic growth in Japan in the 1960s may be characterized by the decisions of investors who considered the supply of quality labor as virtually unlimited.     

Imported modernity and local design: the creation of resilient public spaces in late Ottoman Palestine, 1878–1918

ABSTRACT

Jewish colonies were established in rural areas of Ottoman Palestine in the late nineteenth century; a period full of radical changes, including the industrial revolution, political and cultural shifts in the Ottoman Empire, and social transformations wrought by World War I. These global and local events had a significant impact on everyday life in the colonies, challenging the resilience of the built-up and open public spaces. According to urban space research, the ability of public spaces to withstand change depends on how these spaces are created and defined and the extent to which they evoke a communal sense of ownership and belonging. In light of the above, this paper combines archival and theoretical research in order to examine and characterize the resilience of public spaces in the Jewish colonies in Ottoman Palestine over four decades – from 1878, the foundation of the first colony, to 1918, the end of World War I. Planned and designed by mostly European-educated designers and entrepreneurs, the colonies’ public spaces demonstrated modernity, accommodated change, and created vibrant centres geared to serve a diverse ethnic local population.     

Influence of temperature and substrate shocks on survival and succinic dehydrogenase activity of heterotrophic freshwater bacteria

The influence of temperature shocks on aquatic bacteria was studied in laboratory experiments with regard to population shifts in lake water communities of aerobic heterotrophic bacteria including coliforms. as well as in synthetic mixed cultures of psychrotolerant aquatic isolates. In addition, succinic dehydrogenase activity was used as a parameter of bioactivity. Each experiment was designed to study concomitant effects of elevated levels of organic substrates.

Simultaneous additions of complex nutrients such as 100–300 mg 1⁻¹ of meat peptone to lake water caused a synergistic action of substrate and temperature on population dynamics by depressing population densities at temperatures below 20°C. In contrast, stimulation was observed at higher temperatures particularly for the coliform group. In mixed cultures consisting of Cytophaga, Chromobacterium and Arthrobacter as important members of the heterotrophic microflora of the investigated lake water, substrate accelerated death was induced by temperature shocks beyond the maximum growth temperatures. The succinic dehydrogenase activity of a psychrotolerant strain of Cytophaga failed to show more sensitive responses to temperature shocks than did viable counts.     

国内外流动人口聚居区之比较

我国流动人口聚居区的形成是以城乡二元结构及“民工潮”为背景的。从内在机制上看，我国缘聚型聚居区的形成主要源于传统乡土观念在现代城市条件下的延伸，混居型聚居区的形成则主要源于进城农民为谋生营利而被动的作出共同的区位选择的被动性结果，这与城市房源的供应状况、“连锁流迁”的多源性、流入地的社会结构等因素有着密切的关系。人口流动相对自由、种族矛盾、“矿产开采”经济活动使得西方国家流动人口聚居区基本上都是缘聚型聚居区。建构国内流动人口聚居区整合的系统，可以为社区的综合性整合提供了一个大体的研究框架。     

大城市边区城市化特征和核心城市功能地域规划策略——以广州市白云区嘉禾组团为例

城市化转型是大城市边缘区的发展趋势,包括经济、人口、用地、交通、景观等方面特征的具体转变。本文以广州市白云区嘉禾组团为例,分析大城市边缘区现状发展特征。结合大城市主城区空间和功能拓展等趋势,分析边缘区城市化的普遍趋势：产业从工业主导向服务业主导转型,用地从城乡交错向布局有序转型,交通功能从对外通道向内外网络转型,景观环境从杂乱污染向山水融城转型。进而提出核心城市功能地域在边缘区城市化转型中的重要作用,提出核心城市功能地域应科学合理划定发展范围、培育具有功能带动和辐射作用的城市功能、构建与主城区紧密联系的城市快速交通设施和构建满足城市功能和城市活动需求的景观设施。     

On the contribution of out-migration to changes in net migration: A time series confirmation of Beale's cross-sectional results

Recent cross-sectional studies of population migration patterns have consistently failed to find any relationship between the economic conditions prevalent in an area and the propensity of its inhabitants to emigrate. Changes in the rate of out-migration apparently occur only slowly as the age composition and mobility history of the population change. Thus, in the short run, changes in out-migration are small and contribute little to changes in net migration. This article tests this model of the migration process by making a time series analysis of gross and net migration between Japanese prefectures. We find that, among rural areas, changes in out-migration are a consistently significant component of changes in net migration. If changes in net migration reflect changes in economic conditions in these areas, then one can only conclude that the latter do have an effect on out-migration rates, an effect which is missed by cross-sectional studies. Beale's graphical analysis, which is also cross-sectional, is a notable exception and would have predicted our results.This study was supported in part by a grant from the National Science Foundation.     

Shifting Trajectories of Homeownership in Japan

In contemporary Japanese society, ‘post-bubble’ housing debates are being shaped by labour market restructuring, demographic change and policy shifts. In this context, this paper explores shifting trajectories of homeownership using three specific housing debates: ‘the emergence of a gap society’, ‘increasing single-person households’ and ‘housing assets in later life’. By exploring these various debates, it attempts to highlight how housing, demography and social policy interact at different levels and in different areas to produce dynamic shifts away from the conventional post-war housing trajectory. Current trends have exhibited shifts away from: the linear upward housing trajectory; the family-centred housing model; the land-orientated housing system; and homeownership dominance per se. The concept of generation is used as a thread to tie the different debates together. Each housing issue is often more relevant to a particular generation, but relationships between generations within families and society add to the dynamism to the current shifts.     

Microbial community dynamics during start-up of acidogenic anaerobic reactors

Start-up of two acidogenic reactors under mesophilic (37 degrees C) and thermophilic (55 degrees C) conditions was carried out with methanogenic granular sludge as an inoculum and dairy wastewater as feed. During these 71 days of the start-up period, microbial community dynamics in these two acidogenic reactors, as monitored by denaturing gradient gel electrophoresis (DGGE) and dot-blot hybridization with group-specific oligonucleotide probes, was correlated to reactor performance. Due to pH drop to 5.5, DGGE community fingerprints for domains Bacteria and Archaea populations showed significant shifts after 13 days of operation, and this change was accompanied with an increase in volatile fatty acid production, a decrease in methane formation, and rapid sludge disintegration. Dot-blot hybridization results further indicated that the decrease in methane production was related to the decrease in Archaea population in particular with methanogens from 34.1% of total 16S-rRNA in the seed sludge to 8% within the first 13 days, and to 2-5% at day 71. Among the methanogens monitored, the class Methanomicrobiales was the most abundant followed up by Methanobacteriales and Methanococcales. Due to an elevated temperature, the microbial community change was more significant and rapid in the thermophilic reactor than in the mesophilic reactor. Significant microbial population changes took place at the first 13 days for both reactors, but a longer period up to 71 days was required to establish a microbial community with a stable metabolic activity.     

Quantitative determination of the population biological activity of biological sludges used in the activated sludge waste water treatment process

The population biological activity of biological sludges used in the activated sludge waste water treatment process is defined as that minimum amount of biological sludge, still able to reduce in a 21 h contact period, the soluble COD of a waste water by one half the value equivalent to the BOD_5d. This A_mg^BOD50% 21 h value was determined by incubating hundred fold serial dilutions of a biological sludge with a previously sterilized waste water and by plotting the residual soluble COD remaining after a 21 h incubation period vs the sludge dilution. The method allows any given biological sludge to be readily assayed on any given waste water. Biological sludges were found stable for periods up to three months in the frozen state or when stored at 4°C. Lyophilization of biological sludges resulted in a severe loss of population biological activity. Biological sludges of trade waste water treatment plants were followed for periods up to 70 days. A correlation was found between the population biological activity and changes in environmental factors such as reduced N and P nutrient feeding, reduced aeration or changes in pH. Minor changes resulted in a decrease in population biological activity. Drastic changes resulted in a modified shape of the soluble COD vs biological sludge dilution curves, presumably reflecting deep modifications of the waste water-treating biological community.     

Using Remotely Sensed Imagery to Detect Urban Change: Viewing Detroit from Space

The data integration capabilities of Geographic Information Systems (GIS) are providing new opportunities for urban analysis. This article describes the work of a multidisciplinary team who used spatial data from NASA's Landsat earth observation satellite to analyze the net vegetation change between 1975 and 1992 in Detroit, Michigan. Furthermore, by integrating the satellite-derived change data with census data from 1970, 1980, and 1990, this research shows how the extensive demographic changes that occurred in Detroit over the past quarter century have resulted in physical landscape changes detectable from space. Strong correlations were found between the patterns of social, economic, and demographic data and the pattern of vegetation change seen in the satellite imagery, both for certain points in time and changes over time. These correlations suggest that the imagery reflects processes of urban growth, inner-city decline, population shifts, and change in urban form.     

National structural change and metropolitan specialization in the United States

The national economy is split into four broad sectors. The observed variation in long-term growth among sectors leads to a shift in the composition of aggregate demand. I test Henderson's propositions, namely that secular shifts in the composition of national demand lead to changes in the numbers and sizes of different types of urban places. The numbers and sizes of places specialized in the information sector has increased while the numbers and sizes of places specialized in manufacturing has decreased or has not changed. Metropolitan population growth and per capita earnings growth are enhanced by specialization in the information sector. Received: 29 January 1998 / Accepted: 9 March 1999     

城乡结合部线性公共空间功能定位新思路

城乡结合部是城市发展到特定阶段所形成的紧靠城区的种不连续的地域实体，是处于城乡之旬，人口密度、建筑密度、产业结构、工作性质、人口构成等要素激烈转换的地带。线性公共空间作为城乡结合部主要公共空间形式，具有得天独厚的区位优势，在功能定位中，应注重体现旅游休闲、文化娱乐、商贸办公职能。     

Education in Architecture

Urban planning is conventionally considered to be strongly influenced by the governmental organization and political system within which it operates. Therefore, one would assume that shifts in planning paradigms would spring forth from these areas. Berlin during the years of division (1945–1989) provides a good opportunity for testing this assumption because the diametrically opposed forms of government would have yielded different urban planning outcomes.

This study presents preliminary evidence from six public housing projects that throws these assumptions into question. The findings presented here suggest that planning paradigm shifts are more closely related to factors that are external to governance, such as economic prosperity and social unrest.