苏州地区城镇化过程中水环境变化及影响因子分析

随着近20年来经济的飞速发展和小城镇建设,苏州地区已成为我国城镇化程度较高的地区之一。但经济增长的同时也对水环境带来了巨大压力,在分析对苏州地区水环境变化的基础上,对人口因素、地区产业结构、行业结构及其城乡生活方式对水环境的影响进行了探讨。     

城市大气降尘污染研究进展

随着城市化的发展,城市降尘污染日益得到人们的关注。本文从城市大气降尘概念入手,阐述了城市降尘的理化特征,重点探讨城市大气降尘污染研究现状和大气降尘重金属污染来源示踪研究,以期为大气环境污染的有效整治和改善城市生态环境的决策与管理提供科学参考依据。     

An analysis of urban development and its environmental impact on the Tampa Bay watershed

Urbanization has transformed natural landscapes into anthropogenic impervious surfaces. Urban land use has become a major driving force for land cover and land use change in the Tampa Bay watershed of west-central Florida. This study investigates urban land use change and its impact on the watershed. The spatial and temporal changes, as well as the development density of urban land use are determined by analyzing the impervious surface distribution using Landsat satellite imagery. Population distribution and density are extracted from the 2000 census data. Non-point source pollution parameters used for measuring water quality are analyzed for the sub-drainage basins of Hillsborough County. The relationships between 2002 urban land use, population distribution and their environmental influences are explored using regression analysis against various non-point source pollutant loadings in these sub-drainage basins. The results suggest that strong associations existed between most pollutant loadings and the extent of impervious surface within each sub-drainage basin in 2002. Population density also exhibits apparent correlations with loading rates of several pollutants. Spatial variations of selected non-point source pollutant loadings are also assessed.     

Impervious surface as an indicator of pH and specific conductance in the urbanizing coastal zone of New Jersey, USA

Impervious surface is often used as an indicator of non-point source pollution in urban areas due to the strong relationship between percent impervious surface cover and water-quality impacts. In many cases, a threshold effect exists where water quality rapidly degrades above a given percent cover, but the exact threshold level appears to vary across regions. This study explores the relationship between pH, specific conductance, and percent impervious surface cover in the urbanizing coastal zone of New Jersey (USA) to determine the nature of the relationship in the region. The results of the analysis suggest the system is very sensitive to impervious surface, with a threshold potentially existing between 2.4% and 5.1% impervious surface cover. An examination of future conditions suggests that by 2020 water quality in more than 50% of the catchments in the study area will be negatively impacted by non-point source pollution associated with impervious surface.     

新型城镇化背景下城乡环境基本公共服务均等化推进路径

新型城镇化迫切需要推进城乡环境基本公共服务均等化,而农村环境公共服务的不足成为实现环境基本公共服务均等化的阻碍和制约。在阐述新型城镇化和城乡环境基本公共服务均等化之间关系的基础上,从环境基本公共服务投入总体不足、供给主体单一、城乡不均等突出等方面指出:当前阶段城乡环境基本公共服务均等化现状和面临的问题。探讨了城镇化背景下城乡环境基本公共服务均等化的发展重点领域,包括饮用水安全保障、清洁的大气、污水垃圾治理设施、环境信息服务等,认为推进城乡环境基本公共服务均等化宜采用政府推动、市场参与、多元化供给的协调推进路径,并提出政策建议。     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Driving factors for coordinating urbanization with conservation of the ecological environment in China

Urbanization is a dominant component of social and economic development around the world, but this process creates tremendous pressure on the ecological environment. How to achieve coordination between urbanization and conservation of this environment has become a key issue, especially in developing countries. It is necessary to identify the driving factors that affect this coordination. To identify these factors, we chose 290 Chinese prefecture-level cities to analyze the driving factors behind urbanization using spatial regression analysis, and explored the spatial differences among regions in these factors. Our results show that industrial upgrading and technological progress were the main factors that promoted coordinated development, with industrialization having positive effects under government management, but with differences among regions in how the driving forces affected coordinated development. Using technological progress to promote industrial upgrading, creating new employment to absorb surplus rural labor, and providing workers with skills training so they can take advantage of new jobs can promote win–win solutions that coordinate urbanization with conservation of the ecological environment.     

Plant–pollinator interactions in urban ecosystems worldwide: A comprehensive review including research funding and policy actions

Urbanization has rapidly increased in recent decades and the negative effects on biodiversity have been widely reported. Urban green areas can contribute to improving human well-being, maintaining biodiversity, and ecosystem services (e.g. pollination). Here we examine the evolution of studies on plant–pollinator interactions in urban ecosystems worldwide, reviewing also research funding and policy actions. We documented a significant increase in the scientific production on the theme in recent years, especially in the temperate region; tropical urban ecosystems are still neglected. Plant–pollinator interactions are threatened by urbanization in complex ways, depending on the studied group (plant or pollinator [generalist or specialist]) and landscape characteristics. Several research opportunities emerge from our review. Research funding and policy actions to pollination/pollinator in urban ecosystems are still scarce and concentrated in developed countries/temperate regions. To make urban green spaces contribute to the maintenance of biodiversity and the provision of ecosystem services, transdisciplinary approaches (ecological–social–economic–cultural) are needed.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01410-z) contains supplementary material, which is available to authorized users.     

河北省农村城镇化对生态环境的影响及对策研究

当前河北省农村城镇化进入了快速发展的时期,由于规划不合理、传统经济增长方式制约、基础设施薄弱等原因,出现了自然资源的浪费和耗竭,以及严重的环境污染问题。因此各级政府须科学合理规划、切实推进农村城镇化,转变农村传统经济增长方式,加大对农村环境基础设施建设的资金投入,同时也要加强对农村居民生态环境保护的教育。     

Long-Term Impacts of Land-Use Change on Non-Point Source Pollutant Loads for the St. Louis Metropolitan Area, USA

A land-use-change simulation model (LEAM) and a non-point-source (NPS) water quality model (L-THIA) were closely coupled as LEAMwq in order to determine the long-term implications of various degree of urbanization on NPS total nitrogen (TN), total suspended particles (TSP), and total phosphorus (TP) loads. A future land-use projection in the St. Louis metropolitan area from 2005 to 2030 using three economic growth scenarios (base, low, and high) and a long-term precipitation dataset were used to predict the mean annual surface runoff and mean annual NPS pollutant loads in the region. Results show mean annual TN increases of 0.21%, 0.13%, and 0.14% by 2030 compared to 2000 under the base, high, and low scenarios, respectively. TSP and TP showed similar trends with different magnitudes. Corresponding changes in annual mean surface runoff were shown to be lower than expected, which might be attributed to the small-scale conversion pattern of land uses. In the most dramatic change (high growth) scenario, the runoff would increase across time but at varying rates, and temporal pollutant loads would result in a more complicated pattern than in the other scenarios. This is attributed to the complex interactions between event mean concentrations of pollutants and the magnitude of changes in land-use acreages. By integrating L-THIA with LEAM, LEAMwq was found to be a useful planning tool to illustrate in a quick and simple manner how future water quality is connected to decision-making on future land-use change.