生态优先原则在通州新城建设过程中的应用

为了协调类似城市间的发展,促进区域统筹,引导其有序竞争,构建和谐的社会,以通州与南通两城市为例,积极引入生态优先的思想来处理两城市的职能关系、空间关系、环境保护以及其他可持续发展问题,力求扬长避短,节约发展成本,促进有序城市组群空间的形成,实现跨区域协调发展。     

Combined and synergistic effects of climate change and urbanization on water quality in the Wolf Bay watershed, southern Alabama

This study investigated potential changes in flow, total suspended solid(TSS) and nutrient(nitrogen and phosphorous) loadings under future climate change, land use/cover(LULC)change and combined change scenarios in the Wolf Bay watershed, southern Alabama,USA. Four Global Circulation Models(GCMs) under three Special Report Emission Scenarios(SRES) of greenhouse gas were used to assess the future climate change(2016–2040). Three projected LULC maps(2030) were employed to reflect different extents of urbanization in future. The individual, combined and synergistic impacts of LULC and climate change on water quantity/quality were analyzed by the Soil and Water Assessment Tool(SWAT).Under the "climate change only" scenario, monthly distribution and projected variation of TSS are expected to follow a pattern similar to streamflow. Nutrients are influenced both by flow and management practices. The variation of Total Nitrogen(TN) and Total Phosphorous(TP) generally follow the flow trend as well. No evident difference in the N:P ratio was projected. Under the "LULC change only" scenario, TN was projected to decrease,mainly due to the shrinkage of croplands. TP will increase in fall and winter. The N:P ratio shows a strong decreasing potential. Under the "combined change" scenario, LULC and climate change effect were considered simultaneously. Results indicate that if future loadings are expected to increase/decrease under any individual scenario, then the combined change will intensify that trend. Conversely, if their effects are in opposite directions, an offsetting effect occurs. Science-based management practices are needed to reduce nutrient loadings to the Bay.     

苏州城市化进程中水环境与人居环境关系研究

城市化进程的加快,使城市化地区的水环境也发生了巨大的改变。随着近20年来的经济发展和城市化建设,苏州地区已成为我国城市化程度较高的城市之一,但经济增长的同时也对城市水环境造成了巨大的影响。研究从人居环境的建设角度探讨了人居环境与水环境的关系,分析了苏州水环境在人居环境建设中的地位、作用及水环境的改变对人居环境的影响,并在此基础上提出了相应的对策措施,为苏州人居环境建设提供了一定的参考依据。     

Biotope mapping in an urban environment and its implications for urban management in Turkey

The biotopes of ecological importance in urban environments worldwide are under the pressure of many negative factors such as urbanization, air pollution, human disturbance, etc. Biotope mapping is an important tool for urban planning and management and of importance for the protection of biotopes for future generations. The biotopes in Antalya city of Turkey, which has faced to a great population pressure due to tourism developments and immigration in the last two decades, were investigated in this study. The selective biotope mapping method was used and major biotope sites were determined by the interpretation of panchromatic aerial photographs, assisted with field verifications. A sensitivity assessment based on two parameters, the rarity and the re-establishment ability of biotopes, was made as it was considered important information for urban planning and management. According to the results of the assessment, the majority of biotopes in Antalya city were found to be very sensitive or sensitive. It was concluded that insufficient legislation, the lack of an ecological urban planning approach and poor urban management are the most important reasons for today's pressures on urban biotopes in Turkey.     

Modelling the response of surface water quality to the urbanization in Xi'an, China

The study investigated the response of surface water quality to urbanization in Xi'an, China. We qualitatively described the change in urban land use from 1996 to 2003, analyzed the status of the surface water environment, and constructed a model of urban expansion to simulate the water environment's response to urbanization. Our results revealed that patterns of land use changed dramatically, the rate of economic growth exceeded that of urbanization during the study period, and increasing urban land use was correlated with fluctuations in water quality. The simulated results suggested that urbanization had reached the environmental carrying capacity based on the average land utility and the marginal costs of pollution.     

Spatial Analysis of Soil Erosion and Sediment Fluxes: A Paired Watershed Study of Two Rappahannock River Tributaries, Stafford County, Virginia

Soil erosion is a serious problem in areas with expanding construction, agricultural production, and improper storm water management. It is important to understand the major processes affecting sediment delivery to surficial water bodies in order to tailor effective mitigation and outreach activities. This study analyzes how naturally occurring and anthropogenic influences, such as urbanization and soil disturbance on steep slopes, are reflected in the amount of soil erosion and sediment delivery within sub-watershed-sized areas. In this study, two sub-watersheds of the Rappahannock River, Horsepen Run and Little Falls Run, were analyzed using the Revised Universal Soil Loss Equation (RUSLE) and a sediment delivery ratio (SDR) to estimate annual sediment flux rates. The RUSLE/SDR analyses for Horsepen Run and Little Falls Run predicted 298 Mg/y and 234 Mg/y, respectively, but nearly identical per-unit-area sediment flux rates of 0.15 Mg/ha/y and 0.18 Mg/ha/y. Suspended sediment sampling indicated greater amounts of sediment in Little Falls Run, which is most likely due to anthropogenic influences. Field analyses also suggest that all-terrain vehicle crossings represent the majority of sediment flux derived from forested areas of Horsepen Run. The combined RUSLE/SDR and field sampling data indicate that small-scale anthropogenic disturbances (ATV trails and construction sites) play a major role in overall sediment flux rates for both basins and that these sites must be properly accounted for when evaluating sediment flux rates at a sub-watershed scale.     

Linking biomarkers to reproductive success of caged fathead minnows in streams with increasing urbanization

Reproductive and oxidative stress biomarkers have been recommended as tools to assess the health of aquatic organisms. Though validated in the laboratory, there are few studies that tie a change in gene expression to adverse reproductive or population outcomes in the field. This paper looked at 17 streams with varying degrees of urbanization to assess the use of biomarkers associated with reproduction or stress in predicting reproductive success of fathead minnows. In addition, the relationship between biomarkers and water quality measures in streams with varying degrees of urbanization was examined. Liver vitellogenin mRNA was correlated with reproduction within a period of 11 d prior to sampling irrespective of habitat, but its correlation with egg output declined at 12 d and beyond indicating its usefulness as a short-term biomarker but its limits as a biomarker of total reproductive output. Stress biomarkers such as glutathione S-transferase may be better correlated with factors affecting reproduction over a longer term. There was a significant correlation between GST mRNA and a variety of anthropogenic pollutants. There was also an inverse correlation between glutathione S-transferase and the amount of the watershed designated as wetland. Egg production over the 21-d was negatively correlated with the amount of urbanization and positively correlated to wetland habitats. This study supports the development of multiple biomarkers linking oxidative stress and other non-reproductive endpoints to changes in aquatic habitats will be useful for predicting the health of fish populations and identifying the environmental factors that may need mitigation for sustainable population management.     

上海城市拓展及其环境影响的模拟研究

采用基于元胞自动机的SLEUTH模型模拟上海市1988-2004年间的城市化进程.上海地区的发展进程主要是以中必向外围拓展的面状城市化,加之沿交通干线的线状城市化.城市化的主要影响因子包括人口增长和经济增长,SLEUTH模型与系统动力学模型相耦合,模拟了3个情景设置(基础情景、生态优先情景和道路交通规划引导情景)下20...     

新型城镇化所存在的资源环境问题及对策初探

新型城镇化是我国城镇化发展的必然选择,是我国城镇化健康发展的根本保证。土地资源、水资源、能源等和生态环境是城镇发展的基础和根本保障。城镇化的快速发展导致一系列资源环境问题,因而,城镇化与资源环境有着密切的关系。本文从我国新型城镇化的发展背景、内涵出发,从水资源、土地资源、能源、环境容量几个方面深入探讨了我国新型城镇化所存在的资源环境问题,并在此基础上提出对策,这对于促进新型城镇化的健康发展和我国资源环境的可持续发展均具有重要的学术价值与实践意义。