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891.
C. B. Griffin 《Journal of the American Water Resources Association》1999,35(3):505-518
ABSTRACT: There is increasing interest in using watershed councils to provide information to public natural resource managers, particularly in the western states. Watershed councils are composed of interested governmental and nongovernmental stakeholders that form to collaboratively manage water and other natural resources at the scale of a watershed. This research is the first step in a multi-step policy analysis designed to answer the question of whether watershed councils are an improvement over traditional methods of public involvement in natural resource management. This paper outlines why watershed councils form and discusses their structure and operation. There is considerable variability in terms of watershed councils' goals, their effectiveness, stakeholder composition, their involvement in the “real” decision-making process, types of participation that are allowed, leadership, financing, decision-making procedures, efficiency, and temporal scale. These structural components are presented as a framework that can be used by researchers to develop criteria to evaluate watershed councils. 相似文献
892.
Melissa L. Mika Randel L. Dymond Marcus F. Aguilar Clayton C. Hodges 《Journal of the American Water Resources Association》2019,55(5):1216-1234
The development of Watershed Management Plans (WMPs) in urban areas aids municipalities in allocating resources, engaging the public and stakeholders, addressing water quality regulations, and mitigating issues related to stormwater runoff and flooding. In this study, 124 urban WMPs across the United States were reviewed to characterize historic approaches and identify emerging trends in watershed planning. Planning methods and tools were qualitatively evaluated, followed by statistical analyses of a subset of 63 WMPs to identify relationships between planning factors. Plans developed by a municipality or consultant were associated with more occurrences of hydrologic modeling and site‐specific recommendations, and fewer occurrences of characterizing social watershed factors, than plans authored by agencies, organizations, or universities. WMPs in the past decade exhibited greater frequency in the use of pollutant load models and spatially explicit hydrologic and hydraulic models. Project prioritization was found to increasingly focus on feasibility to implement proposed strategies. More recent plans additionally exhibited greater consideration for water quality, ecological health, and public participation. Innovation in planning methods and consideration of future watershed conditions are primary areas that were found to be deficient in the study WMPs, although analysis methods and tools continue to improve in the wake of advancing technology and data availability. 相似文献
893.
Antarctic specially protected areas (ASPAs) are a key regulatory mechanism for protecting Antarctic environmental values. Previous evaluations of the effectiveness of the ASPA system focused on its representativeness and design characteristics, presenting a compelling rationale for its systematic revision. Upgrading the system could increase the representation of values within ASPAs, but representation alone does not guarantee the avoided loss or improvement of those values. Identifying factors that influence the effectiveness of ASPAs would inform the design and management of an ASPA system with the greatest capacity to deliver its intended conservation outcomes. To facilitate evaluations of ASPA effectiveness, we devised a research and policy agenda that includes articulating a theory of change for what outcomes ASPAs generate and how; building evaluation principles into ASPA design and designation processes; employing complementary approaches to evaluate multiple dimensions of effectiveness; and extending evaluation findings to identify and exploit drivers of positive conservation impact. Implementing these approaches will enhance the efficacy of ASPAs as a management tool, potentially leading to improved outcomes for Antarctic natural values in an era of rapid global change. Evaluación del impacto de conservación de las áreas protegidas de la Antártida 相似文献
894.
我国的农业非点源污染治理正处于攻坚期,但部分政策一定程度上缺少具体执行标准和规范,难以执行到位,法律法规碎片化、分散且难以评估执行效果。本文从美国治理非点源的国际经验出发,梳理了联邦层面的法律法规、农业环境管理机构的运作形式以及州层面流域管理规划和非点源控制计划。最后,根据国际经验提出了如下建议:一是建议要求各省在农业规划中加入推进农业流域治理清单;二是建议制定流域地表水质达标规划,实现点源与非点源联合管理;三是建议形成最佳管理实践规范技术指南,并对执行者进行相应补贴,形成监管机制;四是建议建立农业绿色补贴制度,鼓励地方形成可持续的农业发展机制。 相似文献
895.
GIS和情景分析辅助的流域水污染控制规划 总被引:14,自引:2,他引:12
总结了流域水污染控制规划中的正向算法和反向算法及其优缺点.以江西赣江流域为例, 以ARCGIS8.1为平台,建立了流域水环境功能区划、污染源、监测断面和排污口等空间数据库. 基于正向算法,利用情景分析法构造了流域水污染控制的4种情景,并在4种情景下生成了对污染源实行逐级控制的10组规划方案. 利用费用函数对各方案的污水处理投资进行估算;结合污染源预测,利用水质模型对各方案进行水质模拟,并将模拟的结果通过GIS的可视化表达来进行辅助决策. 以水质达标和投资费用作为规划方案的决策依据,通过赣江流域水污染治理的经济可承受能力的分析,优选出2套经济上能承受、水质上可接受的流域水污染控制方案.结果表明,GIS和情景分析法对于流域水污染控制规划在综合性、完整性和可持续性等方面具有良好的指导意义. 相似文献
896.
应急避难场所建设进度优化模型研究 总被引:1,自引:1,他引:0
以规划效率评价为基础,定义了应急避难场所的公益收益,体现在服务性、可达性和安全性3个方面。以全部应急避难场所在整个建设规划期的总公益收益最大化为目标,建立了无偏好和有偏好两类建设进度优化模型,对应急避难场所在规划期内各年的投资额度、建设对象和建设数量进行优化。案例研究结果表明,无偏好模型能最大限度地获得公益收益,但不能很好地表达公众的真实需求;有偏好模型,不可避免会造成一定公益收益损失,但能更多地考虑实际存在的各方面影响因素,更接近真实的决策。实际应用中对模型的选择应根据具体情况确定。 相似文献
897.
研究复杂地形对含硫气井应急计划区(EPZ)划分的影响,为高风险油气田的安全生产提供参考。根据含硫气井井口与周边地形的关系,将复杂地形分为3类;选择不同类型复杂地形的3口含硫气井,采用大涡模拟方法模拟不同H2S释放速率、不同风速和风向、不同井喷点火时间的组合条件下H2S大气扩散质量浓度场,积分计算各井H2S毒性负荷的时空分布。在此基础上,研究EPZ半径与H2S释放速率之间的关系,然后建立以H2S释放速率为指标的不同类型复杂地形含硫气井EPZ的划分方法。结果表明第一类模型计算结果明显大于第二类和第三类模型,第三类模型的计算结果最小,此差异随着H2S释放速率增大而愈显著。计算结果合理,方法适用且可行。 相似文献
898.
Fast economic and social changes in recent years in China have brought massive expansion, redevelopment, and restructuring
of cities. These changes offer cities the opportunity to improve environmental quality through urban green spaces (UGSs) and
to address the challenges of meeting community aspirations. This study explored peoples’ minds concerning UGSs in Guangzhou
city in south China in relation to the following: (1) knowledge and perception of 25 ecosystem services and 8 negative impacts;
(2) attitude toward site condition and management; (3) expectation of landscape design; and (4) preference ranking of venues.
A questionnaire was designed to solicit opinions from 340 respondents randomly chosen from residents living in the study area.
The results indicated widespread recognition of ecosystem services and strong support of UGS programs. Negative responses
were weakly expressed. Amelioration of urban microclimate and environmental quality were emphasized. Environmental functions
stressed in publicity programs, together with aggravating environmental problems in the city, tended to focus respondents’
attention on UGS benefits. Wildlife habitat, species conservation and other natural ecosystem services drew limited concerns.
Awareness of economic benefits was very low. Visual-landscape contributions with strong preference for naturalistic design
and recreational benefits were highlighted. Compared with other countries, Guangzhou residents were characterized by visual–scenic–recreation
orientation and pragmatic–utilitarian perception of UGSs, reflecting underlying differences in the understanding of inherent
ecosystem services of green spaces. Relevant UGS policies and practices could adopt the approaches of market survey, citizen
participation, and precision planning in order to meet increasingly mature and refined demands. Citizens’ understanding of
high-order ecosystem services could be enhanced to encourage appreciation of nature and their associated benefits. 相似文献
899.
Linking linear programming and spatial simulation models to predict landscape effects of forest management alternatives 总被引:1,自引:0,他引:1
Forest management planners require analytical tools to assess the effects of alternative strategies on the sometimes disparate benefits from forests such as timber production and wildlife habitat. We assessed the spatial patterns of alternative management strategies by linking two models that were developed for different purposes. We used a linear programming model (Spectrum) to optimize timber harvest schedules, then a simulation model (HARVEST) to project those schedules in a spatially explicit way and produce maps from which the spatial pattern of habitat could be calculated. We demonstrated the power of this approach by evaluating alternative plans developed for a national forest plan revision in Wisconsin, USA. The amount of forest interior habitat was inversely related to the amount of timber cut, and increased under the alternatives compared to the current plan. The amount of edge habitat was positively related to the amount of timber cut, and increased under all alternatives. The amount of mature northern hardwood interior and edge habitat increased for all alternatives, but mature pine habitat area varied. Mature age classes of all forest types increased, and young classes decreased under all alternatives. The average size of patches (defined by age class) generally decreased. These results are consistent with the design goals of each of the alternatives, but reveal that the spatial differences among the alternatives are modest. These complementary models are valuable for quantifying and comparing the spatial effects of alternative management strategies. 相似文献
900.
Understanding effects of flow alteration on stream biota is essential to developing ecologically sustainable water supply
strategies. We evaluated effects of altering flows via surface water withdrawals and instream reservoirs on stream fish assemblages,
and compared effects with other hypothesized drivers of species richness and assemblage composition. We sampled fishes during
three years in 28 streams used for municipal water supply in the Piedmont region of Georgia, U.S.A. Study sites had permitted
average withdrawal rates that ranged from < 0.05 to > 13 times the stream’s seven-day, ten-year recurrence low flow (7Q10),
and were located directly downstream either from a water supply reservoir or from a withdrawal taken from an unimpounded stream.
Ordination analysis of catch data showed a shift in assemblage composition at reservoir sites corresponding to dominance by
habitat generalist species. Richness of fluvial specialists averaged about 3 fewer species downstream from reservoirs, and
also declined as permitted withdrawal rate increased above about 0.5 to one 7Q10-equivalent of water. Reservoir presence and
withdrawal rate, along with drainage area, accounted for 70% of the among-site variance in fluvial specialist richness and
were better predictor variables than percent of the catchment in urban land use or average streambed sediment size. Increasing
withdrawal rate also increased the odds that a site’s Index of Biotic Integrity score fell below a regulatory threshold indicating
biological impairment. Estimates of reservoir and withdrawal effects on stream biota could be used in predictive landscape
models to support adaptive water supply planning intended to meet societal needs while conserving biological resources. 相似文献