Contribution of different sources to the hydrocarbon pollution during a rain event at the scale of an experimental catchment in Paris centre

Increased impervious surface area is a consequence of urbanization, with correspondent and significant effects on the hydrologic cycle. It is intuitive that an increased proportion of impervious surface brings with it shorter lag times between onset of precipitation and subsequently higher runoff peaks and total volume of runoff in receiving waters. Yet, documentation on quantitative relationships between the extent and type of impervious area and these hydrologic factors remains dispersed across several disciplines. We present a literature review on this subject to better understand and synthesize distinctions among different types of impermeable surface and their relative impacts, and describe the manner in which these surfaces are assessed for their putative impacts on landscape hydrology.     

Happiness and Quality of City Life: The Case of Milan,the Richest Italian City

In this paper we made use of an ad hoc survey on different aspects of city life conducted in 2006 in ten metropolitan areas of the developed word. We investigate the relationship between eight indicators of quality of urban life and subjective well-being expressed by the interviewed citizens, showing that the subjective well-being is strongly correlated with the opportunity of personal relationships, which are given both by the town physical structure (availability of meeting places, accessibility of local shops, mobility) and by the existing social organisation of life (local meeting opportunities, volunteering).     

Local and landscape scale variables impact parasitoid assemblages across an urbanization gradient

Urbanization is a major driver of land cover change worldwide, yet little is known about how urbanization affects beneficial arthropod communities. This study examined how local and landscape scale variables associated with urbanization influenced parasitic Hymenoptera abundance and diversity in residential and commercial properties along a rural to urban landscape gradient in Wisconsin. At a landscape scale, 300 m surrounding sites, land cover percentages were calculated for five cover classes: impervious cover, forest, grassland, agriculture, and urban green space. In addition, habitat diversity (Simpson's index) was calculated for the landscape surrounding study sites. At a local scale (within the boundaries of an individual property), flower diversity, flower area, tree density, and hardscape were measured and related to parasitoid abundance and diversity. During 2006 and 2007, parasitoids were sampled twice a month June-August using yellow sticky cards. Parasitoid abundance was a positive function of flower diversity, a local scale variable. The positive relationship between parasitoid abundance and flower diversity only occurred in areas containing high to moderate levels of urban development, suggesting parasitoids locally benefited from the increased availability of floral resources in urban but not rural sites. Parasitoid diversity decreased as impervious cover increased in the surrounding landscape. Parasitoid diversity decreased by approximately 10% in highly urbanized sites relative to rural sites, a pattern driven by several parasitoid families not detected in urban sites. These results suggest conservation strategies that focus on landscape variables at multiple scales can play an integral role in preserving beneficial arthropods across urban landscapes.     

Analysis of Eastern Mediterranean Oak Forests Over the Period 1965–2003 Using Landscape Indices on a Patch Basis

Although Eastern Mediterranean forests have been exploited for many years, the changing trends in the past 40 years require detailed investigations. Forests in the coastal zone of Lebanon are witnessing major changes mainly because of chaotic urbanisation. The study area at the coastal zone of Lebanon has 96% of its forest cover under oak coppice. The aim of this study is to investigate the applicability of landscape indices on oak forests especially their ability to detect changes between 1965 and 2003. It uses forest canopy closure as another indicator of forest destruction. The 1965 forest map was first checked for its accuracy before being used to extract patch delineations and canopy closures. Landcover types for 2003 were obtained by classifying a SPOT 5 satellite image. FRAGSTATS software was utilised on the 1965 map on a patch basis to calculate patch shapes and sizes. These indices and canopy closures data were investigated for correlation purposes with patterns of forest loss. The edge distances between forest patches in 1965 and new forest patches in 2003 were computed to analyze regeneration processes. Results show that although older forest patches have shown a 48% loss in area, total forest area reached 83%. Abandoned agricultural lands have become new forest. Smaller forest patches (< 40 ha) showed greater losses than large ones. Small and open forest patches recorded greater loss than large and dense patches. Shape indices show no correlation with forest loss. Clearance for agriculture covered 30% of the pre-existing forests, while urban developments accounted for just 4% of forest loss. This research highlights the great need for comprehensive studies of forests using landscape analyses. Such analyses help managers develop practical and relevant conservation measures.     

Post-Soviet forest fragmentation and loss in the Green Belt around Moscow, Russia (1991–2001): a remote sensing perspective

Recent changes in the post-Soviet Russia suggest rapid privatization of previously protected green space around many metropolitan areas. Nowhere is the trend more apparent than near the capital Moscow. Since 1992, formerly protected forests of the Green Belt have been heavily pursued for elite suburban housing development. With the help of two Landsat images (1991 and 2002) and some on-theground analysis, we investigate areas that have experienced the most mature forest loss. We also examine the spatial pattern of this change, as measured objectively by landscape metrics. Within 20 km from the beltline, about 14.6% of the forested land was converted to suburban residential and commercial uses in the 10-year period. The amount of mature forest loss ranged from 14 to 35% per district, but was partially compensated by some new tree plantings and reforestation for a combined tree cover loss of 14.6% for the entire area, including the city of Moscow. If the city proper is excluded, the loss in the suburban green belt was 12.4%. While this is a moderate decrease, it still represents a trend towards less tree cover and more suburban development in the immediate vicinity of a large city, which is likely to result in worsening air quality and negative impacts on wildlife and opportunities for public recreation in suburban forests in the near future.     

Urban influences on the amount and structure of agriculture in the North-Eastern United States

I examine the oft-stated belief that urbanization causes a decline in agricultural activity. Quantitative and structural changes in the agricultural sector between 1969 and 1982 were analyzed for 190 counties in the densely-populated north-eastern region of the United States. Population density, population growth, the farmer/non-farmer ratio in the rural population and the rate of increase in farmland prices were at most weakly correlated with changes in the number of farms, land in farms or total sales of agricultural products. Nor were they related to the changes in the proportion of farmland in crops or sales of agricultural products ha^-1 of farmland. However, these demographic conditions were strongly associated with differences in types of farm, especially part-time vs. full-time and intensive crop farming vs. extensive livestock production. Some of these qualitative adjustments may counteract the most apparent and direct disadvantages of farming in the metropolitan environment.     

Oak forest exploitation and black-locust invasion caused severe shifts in epiphytic lichen communities in Northern Italy

In the last two centuries, native European oak forests have undergone a dramatic decline related to increasing human pressure for agriculture and urbanization. Oak forests were either completely eradicated and transformed into agricultural landscapes or replaced by second-growth formations. Intensive forest management and the replacement of native forests with production forests or arable lands are recognized amongst the main threats to many lichens in Europe. In this study, we used historical information on the epiphytic lichen biota which was hosted in a native oak-dominated forest of Northern Italy to identify shifts of lichen communities due to the changes in land use which occurred during the last two centuries. We also compared the epiphytic lichen communities inhabiting remnant oak forests with those found in the habitats that have replaced native forests: black-locust forests and agrarian landscapes. Almost all the species sampled during the 19th century are now extinct. The loss of native habitat and the subsequent invasion by black locust were probably the most influential factors which affected the composition of lichen communities, causing the local extinction of most of the species historically recorded. Despite the fact that oak remnants host only a few species which were historically recorded, and that they currently are the lichen poorest habitat in the study region, they host lichen assemblages differing from those of black-locust forests and agrarian stands. In these habitats lichen assemblages are mainly composed of species adapted to well-lit, dry conditions and tolerating air pollution and eutrophication. This pattern is likely to be common also in other lowland and hilly regions throughout Northern Italy where oak forests are targeted among the habitats of conservation concern at the European level. For this reason, a national strategy for biodiversity conservation and monitoring of lowlands forests should provide the framework for local restoration projects.     

Effects of land-use master plans in the metropolitan fringe of Japan

The complexity of the landscape in Japanese metropolitan suburbs is the result of high competition among land-demanding economic activities. Although both urban and rural planning legislation has played certain roles in the ordering of land-use, lack of coordination among different zoning systems is still a key issue in the proper development and conservation of limited land. This study investigated the effects of land-use master plans on actual control of land use through maximal utilization of detailed grid data with advanced GIS functions. We analyzed land-use changes in the Osaka metropolitan area for three periods: 1979–1985; 1985–1991; 1991–1996, and compared these changes with the zoning status in each period. This study demonstrates that disordered developments resulted in an increase of vacant areas in urban fringes, which also accelerated the fragmentation of forests and farmlands, causing a disordered spatial pattern from which it will be difficult to recover with the present land-use master plans.     

Effects of land-use master plans in the metropolitan fringe of Japan

The complexity of the landscape in Japanese metropolitan suburbs is the result of high competition among land-demanding economic activities. Although both urban and rural planning legislation has played certain roles in the ordering of land-use, lack of coordination among different zoning systems is still a key issue in the proper development and conservation of limited land. This study investigated the effects of land-use master plans on actual control of land use through maximal utilization of detailed grid data with advanced GIS functions. We analyzed land-use changes in the Osaka metropolitan area for three periods: 1979–1985; 1985–1991; 1991–1996, and compared these changes with the zoning status in each period. This study demonstrates that disordered developments resulted in an increase of vacant areas in urban fringes, which also accelerated the fragmentation of forests and farmlands, causing a disordered spatial pattern from which it will be difficult to recover with the present land-use master plans.     

重庆城市化发展模式研究

重庆是一个二元经济结构明显的直辖市,在研究其城市化发展模式时不能脱离历史阶段和现实条件。因此,文中以城市化发展理论为基础,充分借鉴城市化发达地区经验,结合重庆地区实际情况,提出了重庆城市化“大都市圈 点轴式城市带”的发展模式,即以主城都市圈为中心,以长江、319线(渝怀铁路)为发展轴,以沿线城市为节点,进行串珠式开发,逐步形成以重庆都市圈为中心,万州、涪陵、黔江等城市为区域中心的网络式城镇体系。     

都市区化:中国城市化的新阶段

本文全面分析了都市区以及相关的都市密集区、城市群、都市带等概念的异同 ,从发展的角度对这些概念建立了一定的逻辑关系 ,认为都市区已经成为当代区域发展的基本细胞和城市化的主流组织模式。分析了中国传统城市化战略的不足 ,指出中国以都市区的城市化组织模式取代传统的城镇体系组织模式的重要意义与可能。     

大城市都市区化与规划调控思路的转型

都市化区是大城市由传统单一的城市空间格局,发展到城市和周边地区共融形成整体功能提升的城市化高级形态,都市区化现象必然要求传统的城市规划理念进行转型,以前的相关研究对此较少论及。作者以快速城市化的我国东南沿海城市宁波市为例,分析了宁波市的都市区化发展的空间特点、推动因素,基于此提出了城市规划理念转型的思路。     

Hydro-environmental changes and their influence on the subsurface environment in the context of urban development

The relationship between urban development and hydro-environmental change, particularly with regard to the subsurface environment is examined for three coastal cities affected by Asian monsoons (Tokyo and Osaka in Japan, and Bangkok in Thailand). Major differences in subsurface changes among these cities are closely related to city size, urban structure, and the timing, stage and extent of urbanization as well as the natural environment. The work shows that the urban development has not affected the Bangkok subsurface hydro-environment in the same way it has in Tokyo and Osaka. Three reasons for the difference account for this, (1) Bangkok's abundant annual rainfall, (2) Bangkok has the smallest ratio of impervious pavement surface area, meaning that surface water can more easily infiltrate underground., (3) the degree and extent of urbanization. Bangkok's subsurface hydro-environment has not been heavily affected because underground development has not yet reached deep subterranean areas.By researching yet more cities, at different stages of urbanization to that of Tokyo, Osaka and Bangkok, we plan to quantitatively examine urbanization and its influence on subsurface hydro-environments. This research will help limit damage to developing cities that are not yet experiencing subsurface failures but which are expected to confront these problems in the future.     

Long-term sodium and chloride surface water exports from the Dallas/Fort Worth region

Sodium and chloride in surface water are typically related to urbanization and population density and can have a significant impact on drinking water sources and the subsequent salinity of aquatic ecosystems. While the majority of research has focused on the impact of deicing salts on urban surface waters in colder climates, the effect of urbanization on sodium and chloride concentrations has been found to occur in warmer climates. This study investigated long-term exports of sodium and chloride from watersheds with increasing urbanization in the humid subtropical Dallas-Fort Worth region. We compared exports to characteristics of urbanization: urban land cover, impervious surface area, and calculated contributions from wastewater discharges. Long-term data (1980-2008) were obtained from five USGS gages located in and around the cities. Exports were calculated by regression analysis between concentrations and discharge and normalized for time and the watershed area. Grab samples were collected from June 2009 to May 2010 and sodium and chloride concentrations quantified. Our results show a strong positive relationship between the mean annual sodium and chloride exports from each watershed and the percent urban land cover and impervious surface area. Long-term increases in sodium and chloride fluxes were found for the three watersheds with the highest percentage of urban land cover. The single largest contributor was wastewater effluent that was estimated to contribute approximately half of the total loads in the three urbanized watersheds. Atmospheric deposition and deicing salts accounted for small amounts of the total export for urbanized watersheds. The source of the remaining salt load is still unknown and may be a combination of non-point sources. Estimates of urban salt exports were similar to estimates from northern watersheds affected by deicing salts.     

加入WTO对中国城市化进程

作者从我国就业岗位的变化角度，分析加入WTO后一定时期内给中国城市化进程带来的巨大冲击，以及从长远角度看给中国城市化进程带来的促进作用。并以我国特大和大城市为例探讨了如何抓住这一机遇合理引导中国城市化进程。     

美国和加拿大都市区的划分及我国的借鉴

都市区(Metropolltan Area)是指一个具有较大人口规模的核心区以及空间上与之相连且具有较强经济和社会联系的地区。核心区一般是达到一定规模的城市。     

Biodiversity relationships in urban and suburban parks in Flanders

Urban and suburban parks can play an important role in the conservation of biodiversity, especially in a strongly urbanised region like Flanders (Belgium). A previously developed method for monitoring biodiversity was applied to 15 parks in Flanders. This method took both habitat and species diversity into account and resulted in 13 biodiversity indicators. The results show that urban and suburban parks can have a high species richness, especially if they consist of different more or less semi-natural habitats. The relationships between the biodiversity indicators and the ecological factors affecting the biodiversity were examined using multivariate analyses and correlation techniques. Park area was the main factor explaining the variation in biodiversity indicators, so larger parks could contribute more to the conservation of biodiversity than small ones. A biodiversity score based on habitat diversity and species richness was proposed to summarise and evaluate the biodiversity. This score is not correlated with the park area and is therefore considered as a reliable indicator for comparing biodiversity in parks of different area.     

河北省鹿泉市城乡统筹规划的挑战、路径与空间发展

在区域化发展阶段,大城市空间拓展的边缘地区往往成为开发建设强度最集中、城乡统筹发展问题最突出的焦点地区。受外部与内生发展需求的共同影响,这类地区的发展定位产生了较大幅度的跃升,相应地,城乡空间发展格局也出现较大的不确定性,既有的城镇化与工业化发展路径难以支撑未来的长远发展,这些都是城乡统筹规划需要面对的难题。鹿泉市紧邻石家庄市区,属于大城市空间拓展的边缘地区。其城乡统筹规划从区域背景和鹿泉市发展阶段性的理性判读入手,针对城乡发展面临的核心挑战,提出了两阶段的城镇化路径及兼顾大产业基地与乡镇产业园区建设的工业化路径,采用了将发展路径与空间模式相结合的规划思路,构建了基于城乡要素一体化的空间组织模式,有利于城镇化、工业化的村庄发展指引,基于城乡服务均等化的公共设施布局,基于发展机会均等化的城乡交通体系,基于城乡协调的基础设施布局。     

城市风景园林设计中的新型雨洪控制利用

伴随着城市化进程,大地景观发生了翻天覆地的变化,自然景观被大量建筑物所取代。不透水面积的增加使原有的水循环系统遭到阻碍,也严重地影响了城市生态环境。雨洪问题和水资源匮乏已成为困扰和制约城市发展的难题。有针对性地剖析城市发展中风景园林设计存在的一些问题,阐述新型雨洪控制利用系统与风景园林设计的密切联系,并简要介绍了国内外风景园林设计中的雨洪控制利用实践和启示,以期为中国城市风景园林设计中应用新型雨洪控制利用的理念和技术提供借鉴。     

Evaluation of five landscape-level metrics for measuring the effects of urbanization on landscape structure: the case of Tucson, Arizona, USA

Landscape-level metrics can be used to measure changes in landscape structure over time. Four landscape-level metrics and rank-size distributions were used to describe changes in landscape structure caused by urbanization in a portion of the Tucson, Arizona metropolitan area between 1984 and 1998. This analysis describes what each metric conveys regarding how urbanization affects landscape structure. It also compares the efficacy of rank-size distributions with the other metrics. Results indicate all five metrics provided information about a specific aspect of landscape structure including patch size, shape, or dispersion. Results indicate that rank-size distributions and their scaling exponents are useful because they provide information not available from the other metrics. Rank-size distributions describe the patch-size scaling properties of specific land-cover types, the relative effect of large and small patches on the distribution of patch sizes, the magnitude of change in patch size, where patch sizes differ from what is expected by the regression model, and the range of patch sizes displaying fractal patterns.