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291.
Frank L. Kudrna 《Journal of the American Water Resources Association》1977,13(4):825-834
ABSTRACT: The Chicago Metropolitan Floodwater Management Plan is a cooperative planning program under Public Law 566 of the 83rd Congress (The Watershed Protection and Flood Prevention Act). The planning effort was jointly sponsored by the U.S. Department of Agriculture, Soil Conservation Service, and the Metropolitan Sanitary District of Greater Chicago. The project is unique in that it studies a 1260 square mile (3266 sq. kilometer) watershed, which is approximately 35 percent urbanized and contains approximately 7.5 million people. At present, approximately 4.4 percent or 330,600 people live in a floodplain. It is presently estimated that 80,000 acres (32,000 ha.) of the study area are subject to flooding with a current average annual damage estimated at approximately $10 million. The Plan which has been developed to reduce or eliminate these damages is divided into six separate watershed plans, and has been developed through extensive use of local citizen watershed steering committees. The paper discusses the planning process, public participation and implementation both at an overall river basin level and watershed case study level. 相似文献
292.
E. M. Davis D. M. Casserly J. D. Moore 《Journal of the American Water Resources Association》1977,13(5):895-906
ABSTRACT: Data were developed within a three-year period for indicator bacteria and three species of bacterial pathogens following rural storm event hydrographs. The first flush concept was confirmed in all hydrographs. Bacterial density peaking occurred at or before the hydrograph peaks. FC and FS values were higher in more developed areas than the primary rural test site and their numerical ratios followed similar trends. Chlorine demand of storm waters varied between 8 and 16 mg/l and, the ozone requirement was greater than 32 mg/l in the same waters. Aftergrowth of total coliform bacteria occurred following chlorine and ozone doses of 16 mg/l and 32 mg/l respectively. Fecal coliform, fecal streptococci, Salmonella sp., and Pseudomonas sp. all were reduced to near detectable limits by the disinfectants up to 8 days. Staphylococcus sp. demonstrated a propensity to restablish their populations. Multiple regression analysis of the bacterial groups and species in storm waters suggested the fecal streptococci to have been the most useful group in evaluating bacterial storm water quality, with staphylocci have been closely related insofar as their statistical significance was concerned. 相似文献
293.
Michael N. Beaulac Kenneth H. Reckhow 《Journal of the American Water Resources Association》1982,18(6):1013-1024
ABSTRACT: Lake and watershed management strategies and recent environmental legislation dictate that nonpoht nutrient sources associated with storm water runoff must be assessed. Accordingly, a nutrient flu assessment for phosphorus and nitrogen is conducted through an extensive literature review of nutrient export studies. These studies are reevaluated. The nutrient export coefficients are screened according to sampling design criteria and compiled according to land use. The ecological mechanisms within each land use influencing the magnitude of nutrient flux are also discussed 相似文献
294.
295.
ADENA R. RISSMAN†† LYNN LOZIER† TOSHA COMENDANT‡ PETER KAREIVA§ JOSEPH M. KIESECKER M. REBECCA SHAW† ADINA M. MERENLENDER 《Conservation biology》2007,21(3):709-718
Abstract: Conservation easements are one of the primary tools for conserving biodiversity on private land. Despite their increasing use, little quantitative data are available on what species and habitats conservation easements aim to protect, how much structural development they allow, or what types of land use they commonly permit. To address these knowledge gaps, we surveyed staff responsible for 119 conservation easements established by the largest nonprofit easement holder, The Nature Conservancy, between 1985 and 2004. Most easements (80%) aimed to provide core habitat to protect species or communities on-site, and nearly all were designed to reduce development. Conservation easements also allowed for a wide range of private uses, which may result in additional fragmentation and habitat disturbance. Some residential or commercial use, new structures, or subdivision of the property were permitted on 85% of sampled conservation easements. Over half (56%) allowed some additional buildings, of which 60% restricted structure size or building area. Working landscape easements with ranching, forestry, or farming made up nearly half (46%) of the easement properties sampled and were more likely than easements without these uses to be designated as buffers to enhance biodiversity in the surrounding area. Our results demonstrate the need for clear restrictions on building and subdivision in easements, research on the compatibility of private uses on easement land, and greater public understanding of the trade-offs implicit in the use of conservation easements for biodiversity conservation. 相似文献
296.
How conservation messages are framed will impact the success of our efforts to engage people in conservation action. This is highly relevant in the private land conservation (PLC) sector given the low participation rates of landholders. Using a case study of PLC schemes targeted at Australian landholders, we present the first systematic analysis of communication strategies used by organisations and government departments delivering those schemes to engage the public. We develop a novel approach for analysing the framing of conservation messages that codes the stated benefits of schemes according to value orientation. We categorised the benefits as flowing to either the landholder, to society, or to the environment, corresponding to the egoistic, altruistic and biospheric value orientations that have been shown to influence human behaviour. We find that messages are biased towards environmental benefits. Surprisingly, this is the case even for market-based schemes that have the explicit objective of appealing to production-focussed landholders and those who are not already involved in conservation. The risk is that PLC schemes framed in this way will fail to engage more egoistically oriented landholders and are only likely to appeal to those likely to already be conservation-minded. By understanding the frame in which PLC benefits are communicated, we can begin to understand the types of people who may be engaged by these messages, and who may not be. Results suggest that the framing of the communications for many schemes could be broadened to appeal to a more diverse group (and thus ultimately to a larger group) of landholders. 相似文献
297.
This paper contributes to on-going attempts at bringing together two influential ideas in water governance: Integrated Water Resource Management (IWRM) and adaptive governance. In particular, a tension remains between the call in IWRM for the use of formal institutions, such as river basin organisations, to secure public policy integration, and the assumptions in adaptive governance in favour of informal collaboration between essentially independent policy actors. To clarify this relationship, this article draws on theoretical research on public policy integration, and uses these insights in an empirical setting to identify mechanisms that can facilitate effective policy integration for adaptive water governance. The research is based on recent attempts in Scotland to implement IWRM ideas to improve flood management. Several governance mechanisms were adopted to facilitate the integration of flood, water and rural land use policies. Six Scottish policy regimes are analysed using documentary sources and interviews. Results challenge the idea that collaboration should primarily be built on either river basin organisations or informal mechanisms. We identify a mix of informal and statutory-based mechanisms which may secure political and technocratic commitment to policy integration. 相似文献
298.
农用地资源修正法定级之技术路线探讨——以佛山市高明区为例 总被引:1,自引:0,他引:1
目前我国农用地资源定级很少运用修正法,少数学者对修正法定级做过尝试性的实证研究工作,以期探讨修正法定级技术路线的科学性与可行性.在前人研究的基础上,以佛山高明区为例,探讨了修正法定级之修正基础的确定、修正因素的选择、修正系数的计算、定级指数的确定等几个关键技术步骤,提出了以农用地自然质量等指数作为修正基础,采用标准化方法对修正因素分值进行订正,用连乘法计算农用地质量定级指数来划分农用地级别的修正法定级的技术路线,并与因素法定级的成果进行对比分析与验证. 相似文献
299.
发达与欠发达地区耕地保护行为中的利益机制分析 总被引:6,自引:0,他引:6
俞文华 《中国人口.资源与环境》1997,7(4):22-27
本文从当前发达与欠发达地区耕地保护上的利益矛盾入手,以它们之间的内在经济关系为基础,运用局部均衡分析方法,构建了一个简单的经济模型,对上述矛盾“零和博弈”的长期效应进行了揭示,并讨论了消除这种不良影响的政策或制度安排。 相似文献
300.
改革开放以来,我国城市化过程出现快速发展时期,特别是长江下游地区(长江三角洲及其周边地区),由于人口与产业不断集聚,重大基础设施项目投资加大,道路网密度增加,开发区扩大,使得城市空间迭加扩展,造成了严重的水土资源利用失衡,生态环境日趋恶化,使本地区城市发展出现了许多新问题。以长江下游地区为例,对本区城市化过程中有关水土资源环境恶化、水污染增加、土地资源流失,以及城镇化速度过快的情况,作了深入分析论证,同时对长江下游地区水土资源合理开发利用与保护提出了新的思维、新的方法措施,特别是对如何加强长三角地区水质环境的整治提出了4点切实可行的办法与措施,为本地区的经济发展与生态安全提供科学依据. 相似文献