红层区城镇地下水对建筑物基础腐蚀及防治研究--以天水市为例

地下水对建筑物基础腐蚀是发育广泛、速率缓慢的地质灾害,它对红层区城市基础工程危害尤显突出。以天水市的红层区为例,利用长期积累的大量地下水化学资料,探讨了腐蚀性地下水的成因,提出了防治地下水对建筑物基础腐蚀的对策。     

作为生态和环境保护手段的空间规划:联邦德国的经验及对中国的启示

联邦德国生态环境保护走过了一条污染-治理-预防的道路, 即由技术性和应激性转为政策性和预防性的环境保护。生态环境保护政策和措施由环保活动家,大企业,学术界,地方及联邦各级有关部门共同制定,并由一个国家级综合的监测体系监督执行。公众不仅有权力了解结果,而且也将参与政策措施的制订和监督。德国空间规划包含欧盟,联邦,州,区域,城镇和城市建设6个层面。空间规划,特别是生态环境规划已成为预防生态环境破坏的重要措施。然而,联邦德国生态环境规划实施也面临个人交通和小企业污染以及环保成本提高造成企业区位劣势所带来的挑战。这些经验教训对中国的生态环境保护目标,政策措施的完善及生态空间规划的制订和监督落实,环境评价,特别是规划本身的环境评价具有借鉴意义。具体包括4个方面: 1)生态环境保护政策实现从提高环保技术手段向预防污染产生转变; 2)保证生态环境保护政策及实施的有效性; 3)把空间规划作为实现区域经济和社会稳定可持续发展的手段,提高生态和环保目标的地位; 4)在规划的技术层面上关注居住,休闲,交通和自然保护区用地的增长。     

Spatial distribution and comparative evaluation of phosphorus release rate in benthic sediments of an estuary dam

A series of experiments and simulations were performed to ascertain the rate at which phosphorus is released using a water quality model in Saemangeum Lake, an artificially constructed lake located in an estuary. The general inflow of seawater once a day contributed to the formation of a halocline in the lake water, which caused variation in the vertical concentration of dissolved oxygen. The halocline was mainly observed in the deep downstream regions of Saemangeum Lake that are close to the op...     

EIAs,power and political ecology: Situating resource struggles and the techno-politics of small-scale mining

Academics across disciplines are increasingly employing political ecology lenses to unpack conflicts related to resource extraction. Yet, an area that remains under-researched and under-theorised is how environmental impact assessments (EIAs) are embedded in politics and imagined as sites of power relations. Drawing on long-term fieldwork in Zimbabwe engaging small-scale gold miners, EIA consultants and government officials, this article examines the changing social significance of EIAs during and after a nationwide police operation that was framed by authorities as targeting non-compliance with environmental policy, illegal mining and illicit trading. Among other articulations of dissent, small-scale miners associations protested that EIA enforcement rhetoric served unjustly as a rationale for halting livelihoods and extracting rent from miners in times of economic difficulty. The article challenges EIA narratives that focus narrowly on risk management or governance failure, exploring technocratic obfuscations and how enforcement rhetoric was perceived in relation to criminalisation and coercion, expert environmental consultancy cultures and adapted legacies of colonial practice in contemporary dynamics of rule. Heavy-handed policing under the banner of enforcing order impinged on livelihoods and had counterproductive effects in addressing environmental problems, while complying with expensive EIA report-producing requirements was far beyond the means of most small-scale miners. The article rethinks how technical EIA rhetoric becomes entangled in spaces of contentious politics, the perils of looking only at particular scales of relations to the exclusion of others, and what it means to re-engage Donald Moore’s notion of “shifting alignments and contingent constellations of power.” Suggesting future directions in political ecology theorising in relation to extractive sectors, it calls for careful attention to the situated politics of EIAs – situated in time and space, amid varying relations of power – and how multiple hegemonic practices are conceptualised and challenged.     

Assessment of uncertainty in environmental contours due to parametric uncertainty in models of the dependence structure between metocean variables

A key factor for computing environmental contours is the appropriate modeling of the dependence structure among the environmental variables. It is known that all the information on the dependence structure of a set of random variables is contained in the copulas that define their multivariate probability distribution. Provided that copula parameters are estimated by means of statistical inference using observations, recordings, numerical or historical data, uncertainty is unavoidably introduced in their estimates. Parametric uncertainty in the copulas parameters then introduces uncertainty in the environmental contours. This study deals with the assessment of uncertainty in environmental contours due to parametric uncertainty in the copula models that define the dependence structure of the environmental variables. A point estimation approach is adopted to estimate the statistics of the uncertain coordinates of the environmental contours considering they are given in terms of inverse functions of conditional copulas. A case study is reported using copulas models estimated from storm hindcast data for the Gulf of Mexico. Uncertainty in environmental contours of significant wave height, peak period and wind speed is assessed. The accuracy of the point estimation of the mean and variance of the contour coordinates is validated based on Monte Carlo simulations. A parametric study shows the manner in which greater parametric uncertainty induces larger variability in the environmental contours. The influence of parametric uncertainty for different degrees of association is also analyzed. The results indicate that variability between contours considering parametric uncertainty can be meaningful.     

海洋生态系统服务非市场价值评估框架:内涵、技术与准则

海洋生态系统服务非市场价值评估是将生态系统服务的效用价值量化为货币价值的过程。通过将无形的生态系统效益转化为有形的经济价值,非市场价值评估有利于提高海洋生态系统管理决策的科学性和有效性。然而现有研究对于评估对象的界定以及评估技术的使用缺乏统一的标准,导致评估结果不具有可比性。本文从内涵、技术与准则三个层面构建了海洋生态系统服务非市场价值评估框架:首先,系统分析了生态系统功能、生态系统服务以及生态效益的区别和联系,明确了非市场价值从生态系统到社会经济系统的转化路径;其次,对比阐释了非市场价值评估技术的差异性与适用性,识别出不同评估方法的技术特征;最后,提出了非市场价值评估的应用准则,确保评估过程的有效性和评估结果的可靠性。     

Recreational boaters value biodiversity: The case of the California Channel Islands National Marine Sanctuary

Marine ecosystems provide a range of valuable services, some of which come with market prices to quantify value and others for which markets have not set prices. Lacking perfect information, policy makers are at risk of undercounting non-priced values and services, leading to biases in policy decisions in favor of services valued through markets. Furthermore, understanding users’ valuation of specific site attributes, such as marine biodiversity, can contribute to effective policy decisions. This paper presents a non-market valuation of private recreational boaters (PRBs) in the Channel Islands National Marine Sanctuary located in California, USA, using data from an intercept survey conducted in 2006 and 2007. A Random Utility Model is used to estimate PRBs’ daily trip values and the importance of specific site attributes. The average consumer surplus was estimated at $48.62 per trip, with a total non-market value of non-consumptive private recreational boating of $86,325 annually. PRBs show a preference for visiting locations with lower exposure to prevailing winds and greater species richness and abundance, which to the authors’ knowledge is the first time that PRBs have been found to value biological diversity in site choices. Furthermore, this suggests that improved biodiversity and productivity of marine ecosystems contribute to better recreational experiences. The results from this study reveal the importance of including non-market services and stakeholder's preferences into policy decisions.     

An integrated monitoring framework for the Great Barrier Reef World Heritage Area

Monitoring provides important feedback on how social and environmental systems are tracking and whether or not human activities, including management activities, are having an impact. This paper describes an approach applied to develop an integrated monitoring framework to inform adaptive management of the Great Barrier Reef World Heritage Area, a complex, multi-jurisdictional, multi-sectoral marine system of international importance. It identifies the gaps and opportunities to integrate the existing long-term, short-term and compliance-related monitoring and reporting initiatives to provide the information for more effective and efficient (adaptive) management of the Great Barrier Reef World Heritage Area. And as importantly it aligns expectations among different agencies about how monitoring will inform management. Fifty two high priority values, processes and pressures for management were identified along with 65 existing monitoring programs. Developing the monitoring framework was useful in several ways. First it brought together scientists, policy-makers, managers, and other interested stakeholders with different agendas, philosophies and incentives and established a common purpose, lexicon and language for an integrated monitoring program. Second, it highlighted the importance and usefulness of qualitative conceptual models as a framework for focused discussion around a set of hypotheses with relevance for management. Third, the process started an important conversation about defining and setting a realistic number of monitoring priorities for management. Finally, it has provided direction for how to build on existing initiatives to develop an integrated monitoring program for a globally significant world heritage area.     

How can marine ecosystem services support the Blue Growth agenda?

The EU Blue Growth Agenda targets maritime economic activities that have the sea and the coasts as drivers. These activities are supported by marine Ecosystem Services (ES) in combination, or not, with abiotic outputs from the marine natural capital. This paper analyses Blue Growth activities with regards to the demand and supply of marine ES and Good Environmental Status (GES). The results show that marine provisioning ES support aquaculture and blue biotechnology, while blue energy is supported by marine provisioning ES and by abiotic provisioning, and abiotic provisioning supports extraction of marine mineral resources. Maritime, coastal and cruise tourism is supported by cultural marine ES and cultural settings dependent on marine abiotic structures. All these multi-sectoral economic activities depend on healthy marine and coastal ecosystems that are provided by regulating and maintenance ES combined with the abiotic regulation and maintenance by natural marine physical structures and processes. In order to balance concurrent sectoral interests and achieve sustainable use of marine resources there is the need to consider indicators for demand for ES, which are social and economically driven, and for the supply, which are dependent on ecosystems capacity to provide the required marine ES. Some of the actions foreseeing GES are already anticipated in legislation that underpin Blue Growth, whilst others could benefit from additional regulation, particularly in what concern the exploration and exploitation of marine mineral and biological resources. Blue Growth options require navigating trade-offs between economic, social and environmental aspects.     

Using choice models to inform large marine protected area design

During the last decade a number of Large Marine Protected Areas (LMPAs) – marine protected areas that exceed a minimum size threshold and are often in offshore or open ocean waters – have been designated in an effort to meet marine conservation objectives. Research on the human dimensions of LMPAs is limited, though comprehensive policy analysis requires an understanding of the full range of social, cultural and economic benefits associated with LMPA designation. This paper addresses this need by employing a stated preference choice experiment survey of U.S. west coast households to examine public preferences for different protected area designs sited off the U.S. west coast. Using data from over 3000 randomly selected households in California, Oregon, and Washington we estimate choice models and calculate economic values for a suite of LMPAs that vary in size and in the types of restrictions within area boundaries. Results show that the LMPA size yielding the highest value is ~15.6% of the west coast Federal waters. Results also underscore the importance of restriction type, as there are considerably different threshold sizes above which diminishing returns and negative economic values are derived from no-access reserves, no-take, and multiple-use designations. While the value of any specific configuration can be estimated using the model, results offer insight on optimal use designations from a public perspective for small (< 2.5% of west coast Federal waters), medium (2.5%–~10%) and large (> 10%) LMPAs sited off the U.S. west coast.