TRICK OR TREAT? AN OFFER TO OBTAIN METERED WATER1

ABSTRACT: In this paper we examine the possible reasons why individuals who live in homes facing a flat monthly rate for water accept or reject an offer to have water metering devices installed at no cost to them. A logit model is used to model the discrete choice of acceptance. Since the demand for metering is directly tied to water demand, we estimate demand models for unmetered households in the Reno/Sparks metropolitan area using contingent data obtained by presenting households with hypothetical prices they might encounter under a metering system. Conditional logit and demand models are then used to examine the potential for metering to promote water conservation in the arid Reno/Sparks, Nevada metropolitan area.     

Stationarity: Wanted Dead or Alive?1

Lins, Harry F. and Timothy A. Cohn, 2011. Stationarity: Wanted Dead or Alive? Journal of the American Water Resources Association (JAWRA) 47(3):475‐480. DOI: 10.1111/j.1752‐1688.2011.00542.x Abstract: Aligning engineering practice with natural process behavior would appear, on its face, to be a prudent and reasonable course of action. However, if we do not understand the long‐term characteristics of hydroclimatic processes, how does one find the prudent and reasonable course needed for water management? We consider this question in light of three aspects of existing and unresolved issues affecting hydroclimatic variability and statistical inference: Hurst‐Kolmogorov phenomena; the complications long‐term persistence introduces with respect to statistical understanding; and the dependence of process understanding on arbitrary sampling choices. These problems are not easily addressed. In such circumstances, humility may be more important than physics; a simple model with well‐understood flaws may be preferable to a sophisticated model whose correspondence to reality is uncertain.     

ARE SOILS LIKE SPONGES?1

ABSTRACT: The purpose of this paper is to explore the validity of the old analogy that “soil is like a sponge.” Laboratory experiments were conducted to measure two hydrologic properties of porous media: drainage under gravity, and water potential curves. A tipping bucket rain gage connected to a data logger was used to measure the rate at which water drained under the force of gravity from a trough filled with four saturated porous media ‐ cellulose sponges, topsoil, peat, and a medium sand. Pressure plate techniques were used to determine water potential curves for soil materials and sponges. In terms of relative cumulative discharge from the trough, sponges were intermediate between peat and topsoil. Because of their tremendous water‐holding capacity, sponges discharged more than 2.5 times as much water as did peat. The water potential curve for sponges was fairly flat, like that of topsoil, but the high water content across all pressures (0.30–15.0 bars) indicated some similarity to peat. The results of these experiments suggest that the general patterns of water retention and release in soil materials and sponges are similar and vary only in degree.     

生态旅游:我们准备好了吗?

近几年来,作为一种新兴的旅游形式,生态旅游在我国可谓方兴未艾,回归大自然逐渐成为一种时尚。“五·一”放长假期间,各地纷纷打出“生态旅游”的招牌吸引游人。但由于一些旅游开发项目缺少科学的规划与管理,也出现旅游开发到哪里,污染与破坏就带到哪里的苗头。生态旅游开发对于自然环境的破坏主要集中在以下几个方面:第一,由于规划开发不当造成的生态系统破坏;第二,游客过度进入超过环境承载力造成破坏;第三,消费者进入以后产生的垃圾污染没有得到很好的回收和管理而造成的破坏。据我国人与生物圈国家委员会的一份调查资料显示:一些自然保…     

国际极年:意味着什么?

被科考界称为南北极科学考察“奥林匹克”盛会的第四次国际极年活动于2007年3月1日正式启动。通过极年活动,可以积累大量资料和科学发展成果,从而增加环境保护能力和改进预报系统。作为本次科考计划的一部分,我国将争取在南极内陆建立第三个科学考察站。本文作者位梦华是国家地震局研究员,曾经率队赴北极科考。多年来,他一直为中国的北极科考事业奔走呼吁。     

环保:个人可以做什么?

环境保护是一个公益问题,涉及各个群体的利益,需要各个层面共同参与,从公民到政府各司其职,构建共同参与、共同建设的环保意识,才能更好地维护环境。在这一过程中,政府需要加大环保宣传和教育,并对环保NGO提供更多的支持,鼓励NGO进行环保活动,开展环保宣传,引导人们积极实施保护环境的行动,因为环保意识最终应该是一种理性的行动意识。     

人类中心主义:生态危机的罪魁祸首?

自人猿相揖别以来,人与自然之间的关系问题便贯穿于整个人类发展史.特别是20世纪60年代以来,伴随着人口急增、科技进步和社会发展而出现的环境污染、生态失衡等一系列危害到人类生存与发展的社会现象的凸显,学术界对人与自然之间关系的思考更加深刻.     

Is Urban Stream Restoration Worth It?1

Kenney, Melissa A., Peter R. Wilcock, Benjamin F. Hobbs, Nicholas E. Flores, and Daniela C. Martínez, 2012. Is Urban Stream Restoration Worth It? Journal of the American Water Resources Association (JAWRA) 48(3): 603-615. DOI: 10.1111/j.1752-1688.2011.00635.x Abstract: Public investment in urban stream restoration is growing, yet little has been done to quantify whether its benefits outweigh its cost. The most common drivers of urban stream projects are water quality improvement and infrastructure protection, although recreational and aesthetic benefits are often important community goals. We use standard economic methods to show that these contributions of restoration can be quantified and compared to costs. The approach is demonstrated with a case study in Baltimore, Maryland, a city with a legal mandate to reduce its pollutant load. Typical urban stream restoration costs of US$500-1,200 per foot are larger than the cost of the least expensive alternatives for management of nitrogen loads from stormwater (here, detention ponds, equivalent to $30-120 per foot of restored stream) and for protecting infrastructure (rip-rap armoring of streambanks, at $0-120 per foot). However, the higher costs of stream restoration can in some cases be justified by its aesthetic and recreational benefits, valued using a contingent valuation survey at $560-1,100 per foot. We do not intend to provide a definitive answer regarding the worth of stream restoration, but demonstrate that questions of worth can be asked and answered. Broader application of economic analysis would provide a defensible basis for understanding restoration benefits and for making restoration decisions.     

又是一年看海季:是天灾?还是人祸?

正"城市看海",饱含讥讽含义的名词成为当今城市下雨场景的"代言"。"井盖吞人"、"城市看海"这些看似"天灾"的背后,难道就没有"人祸"的原因?这个夏天,对于深处全国抗洪斗争中心的武汉市来说,"看海模式"已经不只是一句调侃,而是演变成了一场全城严重内涝、堤防险情丛生的洪水灾情。除一周降雨量达到历史极值的"天灾"因素外,城镇化快速发展过程中"城进湖退",城市排水设     

揭秘中央环保督察组:成员有谁?有啥规矩?

正督察组要求各成员严格执行保密制度、请示报告制度和请销假制度,没有经过批准不准离开驻地。最近一段时间,"中央环保督察"成为人们关注的焦点和热议的话题。这不仅是因为,督察组一到,能迅速有效地解决人们身边的污染问题,震慑污染制造者,也因为这是对地方环保和生态文明建设的一次"问诊把脉"。     

A Field-Based Evaluation of Wet Retention Ponds: How Effective Are Ponds at Water Quantity Control?1

Hancock, Gregory S., Jonathan W. Holley, and Randolph M. Chambers, 2010. A Field-Based Evaluation of Wet Retention Ponds: How Effective Are Ponds at Water Quantity Control? Journal of the American Water Resources Association (JAWRA) 46(6):1145–1158. DOI: 10.1111/j.1752-1688.2010.00481.x Abstract: Wet retention ponds are widely used structural stormwater best management practices (BMPs) with the primary goals of reducing peak flows and extending flow duration. Despite widespread use, few field-based studies have evaluated the success of wet retention ponds at meeting these goals. We determined pond elevation, flow rate, and pond volume over four years in five suburban watersheds in James City County, Virginia. We selected five ponds designed under regulations requiring a 24 hour inflow-to-outflow centroid lag time for a one year, 24 hour design storm. We used pressure transducers to measure pond water surface elevation at 5 min intervals, and calculated pond outflow and volume using rating curves obtained from site stormwater management plans (SWMPs). Peak inflows, peak outflows, and runoff ratios frequently exceeded SWMP calculations in measured events. Four ponds never achieved the required 24 hour inflow-to-outflow centroid lag for storms similar to the one year, 24 hour storm. These BMPs fail to achieve regulatory goals for channel protection because of regulatory loopholes, underprediction of rainfall intensity, unrealistic predictions of postdevelopment flows in SWMPs, and the inability of wet retention ponds to reduce overall runoff volume. While specific to one locality, the shortcomings highlighted suggest similar field-based assessments of retention pond performance are needed in other locations.     

Local Agenda 21: Substance or Spin?

Local Agenda 21 has become well embedded as a mechanism for promoting sustainable development strategies at the municipal level. Quantitative studies indicate an impressive rate of progress on strategy production and adoption. This paper reports on qualitative research focused mainly on four innovative UK case studies, and explores the reality of experiences as revealed by participantsin Local Agenda 21. It considers the nature of claims made in relation to sustainability networks, the role of local government and stakeholder characteristics. The paper concludes that, whilst many of the claims about LA 21 are intractable to test, there is some evidence of genuine attainment. This relates mainly to processes of strategy production, stimulation of environmental citizenship, inclusion of various sectors, challenging traditional assumptions and actions, and assisting local democracy.     

Recycling in Jerusalem: right or privilege?

This study analyses disparities in the provision of environmental services in Jerusalem, specifically through the distribution of recycling bins. The allocation of recycling bins in Jerusalem is uneven. Some neighbourhoods have more than their share of infrastructure, while others do not have any recycling bins at all. The spatial distribution of recycling bins throughout the city is analysed across the ethno-religious and socioeconomic divides, enabling us to determine whether the opportunity to recycle is a right or a privilege. The findings demonstrate that the Arab areas are literally not serviced. Ultra-Orthodox (Haredi) Jewish neighbourhoods are discriminated against unless socioeconomic levels and population size are controlled. Therefore, waste-management policies reproduce social inequalities resulting in environmental injustice. Due to the fact that recycling in Jerusalem is voluntary and not obligatory, and that in general the public wants to recycle, the opportunity to recycle is indeed a privilege.     

探究:污水处理厂因何步履沉重?

“建一个赔一个”“,谁治污谁亏损”,污水处理厂的建设运营似乎陷入了一个怪圈,拧成了一个“死结”,现状令人尴尬……2004年,《经济日报》记者在淮河干流上最大的三个城市——安徽阜阳、淮南和蚌埠逐个走访时发现,污水处理厂个个赔钱,原因是管     

2008:中国企业“从良年”?

30年来,中国式能量大爆发:做了无数的事;生产了无数的产品。可惜,许多事是粗放、草率、野蛮、血腥的;许多产品是低级、劣质的。而代价很沉重:消费者饱受摧残,自然界饱受摧残,中国形象饱受摧残。2008年,企业的坏年头。从今以后,企业干坏事越来越难。日益严格而公正的中国社会,正在明确地引导一股潮流:只有好企业才允许生存。