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421.
Ge Sun Steven G. McNulty Jennifer A. Moore Myers Erika C. Cohen 《Journal of the American Water Resources Association》2008,44(6):1441-1457
Abstract: Assessment of long‐term impacts of projected changes in climate, population, and land use and land cover on regional water resource is critical to the sustainable development of the southeastern United States. The objective of this study was to fully budget annual water availability for water supply (precipitation ? evapotranspiration + groundwater supply + return flow) and demand from commercial, domestic, industrial, irrigation, livestock, mining, and thermoelectric uses. The Water Supply Stress Index and Water Supply Stress Index Ratio were developed to evaluate water stress conditions over time and across the 666 eight‐digit Hydrologic Unit Code basins in the 13 southeastern states. Predictions from two Global Circulation Models (CGC1 and HadCM2Sul), one land use change model, and one human population model, were integrated to project future water supply stress in 2020. We found that population increase greatly stressed water supply in metropolitan areas located in the Piedmont region and Florida. Predicted land use and land cover changes will have little effect on water quantity and water supply‐water demand relationship. In contrast, climate changes had the most pronounced effects on regional water supply and demand, especially in western Texas where water stress was historically highest in the study region. The simulation system developed by this study is useful for water resource planners to address water shortage problems such as those experienced during 2007 in the study region. Future studies should focus on refining the water supply term to include flow exchanges between watersheds and constraints of water quality and environmental flows to water availability for human use. 相似文献
422.
Brack W Klamer HJ López de Alda M Barceló D 《Environmental science and pollution research international》2007,14(1):30-38
Background, Aim and Scope
Extensive monitoring programs on chemical contamination are run in many European river basins. With respect to the implementation
of the European Union (EU) Water Framework Directive (WFD), these programs are increasingly accompanied by monitoring the
ecological status of the river basins. Assuming an impact of chemical contamination on the ecological status, the assignment
of effects in aquatic ecosystems to those stressors that cause the effects is a prerequisite for taking political or technical
measures to achieve the goals of the WFD. Thus, one focus of present European research is on toxicant identification in European
river basins in order to allow for a reduction of toxic pressure on aquatic ecosystems according to the WFD.
Main Features:
An overview is presented on studies that were performed to link chemical pollution in European river basins to measurable
ecotoxic effects. This includes correlation-based approaches as well as investigations that apply effect-directed analysis
(EDA) integrating toxicity testing, fractionation and non-target chemical analysis. Effect-based key toxicants that were identified
in European surface waters are compiled and compared to EU priority pollutants. Further needs for research are identified.
Results:
Studies on the identification of effect-based key toxicants focused on mutagenicity, aryl hydrocarbon receptor-mediated effects,
endocrine disruption, green algae, and invertebrates. The identified pollutants include priority pollutants and other well-known
environmental pollutants such as polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins, furans, and biphenyls,
nonylphenol, some pesticides and tributyltin, but also other compounds that were neither considered as environmental pollutants
before nor regulated such as substituted phenols, natural or synthetic estrogens and androgens, dinaphthofurans, 2-(2-naphthalenyl)benzothiophene,
and N-phenyl-2-naphthylamine.
Discussion:
Individual studies at specific sites in a European river basin demonstrated the power of combined biological and chemical
analytical approaches and, particularly, of effect-directed analysis. However, the available information on effect-based key
toxicants is very limited with respect to the entirety of rivers possibly at risk due to chemical contamination and with respect
to toxicological endpoints considered at a specific site. A relatively broad basis of information exists only for estrogenicity
and aryl hydrocarbon, receptor-mediated effects.
Conclusions:
The development of tools and strategies for an identification of key toxicants on a broader scale are a challenging task for
the next years. Since investigations dealing with toxicant identification are too labor and cost-intensive for monitoring
purposes, they have to be focused on the key sites in a river basin. These should include hot spots of contamination, particularly
if there is evidence that they might pose a risk for downstream areas, but may also involve accumulation zones in the lower
reach of a river in order to get an integrated picture on the contamination of the basin.
Perspectives:
While EDA is almost exclusively based on measurable effects in in vitro and in vivo biotests to date, an increasing focus
in the future should be on the integration of EDA into Ecological Risk Assessment and on the development of tools to confirm
EDA-determined key toxicants as stressors in populations, communities and ecosystems. Considering these requirements and applied
in a focused way, toxicant identification may significantly help to implement the Water Framework Directive by providing evidence
on the main stressors and possible mitigation measures in order to improve the ecological status of a river ecosystem. 相似文献
423.
424.
工业化水平区域差异与中国能源消费 总被引:4,自引:0,他引:4
在对30个省区工业化水平进行了聚类分析的基础上,描述了工业化水平的区域差异。通过对中国煤炭、石油两类非可再生能源的消费在区域工业增长中的判别分析,探讨了区域工业化水平对能源消费水平的影响。这种影响以工业能源密度为动因,促成了区域工业化水平与能源消费总量水平的一致性和差异性。研究结果表明:工业能源密度的降低和能源效率的改进有利于工业化水平提高。 相似文献
425.
以对“人地关系”、“发展内涵”和“人的位置”等的系统认识为理性基础.所提出来的可持续发展观.非常强调公平性。经典的可持续发展概念对“公平性”的理解,主要是强调时间维度上的代际公平。我们从地理学的研究核心“人地关系地域系统协调共生理论。和区域可持续发展实证研究的理论和实践的双重角度.认为公平性不仅是时间维度上的代际公平.而且是空间维度上的地域公平和群际公平。就地域公平而言.我们认为.它不仅包括相关地域的公平性而且包括次级地域的公平性和背景地域的公平性。地域公平性的这样的理论认识。在指导区域可持续发展的实践中将具有重要意义。 相似文献
426.
80年代中国宁夏的“吊庄”:农村区域开发和协调人地关系的新模式 总被引:2,自引:0,他引:2
汪一鸣 《中国人口.资源与环境》1993,3(4):36-41
宁夏回族自治区南部以人口超载导致的贫困和水土流失严重著称于世。针对区域开发的这些限制性因素,选择以协调人地关系为指导思想的“吊庄”模式,取得了良好的综合效益。本文主要论述了吊庄移民规划的方针、原则、理论依据、效益和成功经验。 相似文献
427.
Desertification is one of the most serious eco-environmental problems around Qinghai Lake. Based on GIS and RS, GIS analysis was used to obtain the information of spatial-temporal change and different pattern of desertification in each county around Qinghai Lake in four phases of 1976, 1987, 1995 and 2006. Using the function of intersect and overlay supported by ARCGIS, with analyzing attributes of vector RS images, we obtained transition data and established transfer matrix of land-use types in recent 30 years, besides, protracted land-use transition maps of all desertification classes. In further, we analyzed transition quantity and direction of desertification in each county, moreover, reconstructed the process of spatial-temporal evolution of desertification. The results are showed below: (1) it′s the transition between desertified land and others but not in the desertified that played the main role in Gangcha and Gonghe County, while the transfer between desertified lands were greater than that with other land-use types in Haiyan County. (2) Extremely severe desertified land mainly distributes in Ketu and Sand Islands that belongs to Haiyan County, and moderate desertified land in riversides of Gangcha County, also, the light desertification expanded too rapidly to become the most desertified land-use type in the surrounding of Qinghai Lake since 1976. (3) By using relative change rate of desertified land, the regional variability rank from top to toe was Gangcha, Haiyan and Gonghe. 相似文献
428.
国家竞争优势论是我国目前较流行的国际贸易理论学说,它无论在国家层面还是在区域层面,均对制定相应的区域发展战略具有积极的作用。基于对波特关于国家竞争优势论的理解,阐述了它对我国开展泛珠三角区域合作的若干启示。 相似文献
429.
区域旅游协同发展是区域旅游合作的高级形式,应以系统理论、比较优势理论、资源赋存理论、梯度推移理论为基本理论依据。它是实现区域旅游规模经济的必要条件,解决地区旅游经济发展不平衡的重要途径,发挥地区旅游资源比较优势的有效手段,满足旅游者求异心理、提高游客满意度的重要方法。区域旅游整体形象建设的重要举措与旅游规划的重要指导思想对区域旅游发展在理论上与实践上都具有重要意义。 相似文献
430.
层次分析法在区域湖泊水资源可持续发展评价中的应用 总被引:40,自引:1,他引:39
依据可持续发展理论,区域可持续发展系统一般由人口、资源、环境、经浊和社会五个子系统组成。本文从四个方面(人对资源环境的需求;资源环境的需求;经济发展的需求;社会发展的需求)提出区域湖泊水资源可持续发展的5指标体系。并用层次分析法计算各指标的权重,用于评价区域湖泊水资源可持续发展的保证程度,结果表明:区域湖泊水资源可持续发展指标体系的26个指标中,与人民群众生活息息相关的居民对水物满意程度(P13) 相似文献