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61.
The Stream and Its Altered Valley: Integrating Landscape Ecology into Environmental Assessments of Agro-Ecosystems 总被引:2,自引:0,他引:2
Little is known about the importance of landscape and land cover to the implementation and performance of agricultural conservation projects designed to improve stream quality. In our study, we addressed the potential importance of landscape and land cover to conservation projects by measuring variation across 191 μ-basins (100–2400 ha) and integrating the observed variation into a study design aimed at determining the effectiveness of conservation projects. Our findings indicate that there are strong gradients across which landscape and land cover attributes vary. Land cover varied along a gradient of agricultural intensity, basin morphometry across gradients of stream closure and basin size, basin substrate was described by variation in drumlin formation, glacial landform type, and soil drainage, while agricultural conservation projects varied according to the level of project implementation. Correlation of these gradients found several associations between landscape and land cover, indicating that agricultural intensity was being constrained predominantly by drumlin formation and glacial landform type. Landscape and land cover did not appear to be determining factors in the implementation of conservation projects by land owners. Based on these findings we chose 32 μ-basins which represented the variability along each of the defined gradients for further study. We conclude that landscape scale variables demonstrate important variation and covariation that can and should be integrated into study designs for the assessment of streams and human activities affecting streams. 相似文献
62.
农村生活污水治理示范工程的成本有效性研究——以上海和苏南地区为例 总被引:3,自引:0,他引:3
成本有效性是农村生活污水治理工程从示范到普及推广的生命线.本文在上海和苏南地区9个示范工程调研的基础上,将农村生活污水的治理技术简化为"城镇污水处理厂小型化"和"自然处理系统"两种工艺,对示范工程的成本有效性进行了分析.研究发现,示范工程在管网费用、设备费用、主地占用成本和日常运营费用等方面都存在成本下降的空间.针对这些问题,本文提出了相应的政策建议:合理的项目选址是影响管网费用的决定性因素;政府层面的集中研发可以削减单个项目的重复研发费用;设定工程建造标准可以避免土地利用和工程建设中不必要的浪费;农民和第三方企业的广泛参与则可以节省建设和运营成本,更重要的是可以保证工程建成后的有效运行. 相似文献
63.
64.
结合实践工作,从建设项目竣工环境保护验收监测的前期准备、现场监测、样品交接与分析、数据处理及报告编制、验收监测超标情况的处理等方面简述了的经验和体会。指出目前验收监测规范执行中存在的验收条件、管理检查、现场质控、监督管理等方面问题,提出尽快制定或修订相关标准、验收技术规范及详细的实施细则,确保验收工作规范化、程序化的建议。 相似文献
65.
葛洲坝对长江径流过程的影响 总被引:5,自引:0,他引:5
水流是河流生境的主要决定因素之一,影响生物群落的组成和多样性。河流径流过程及特征可以通过水文参数值及其统计特征来反映,包括水文值的大小、发生时间、持续时间、发生频率和变化特征等。水利工程会改变河流天然径流过程。采用IHA法对葛洲坝的河流径流过程影响进行了评价,结果显示总体上葛洲坝水利枢纽对河流天然径流的改变不大,但其一定的削峰坦化作用可能是上涨率和下降率等参数值在建坝后发生一定变化的原因。 相似文献
66.
对现有安全维度研究进行总结,结合中国项目安全管理特征以及地铁工程特征,在专家调查及一轮补充调查的基础上,通过决策实验室分析法(DEMATEL)对地铁工程建设安全气候的维度进行筛选,获得可以对安全效果进行预测的安全气候的维度。结合各个维度在安全气候问卷调查中的调研要素,概括中国地铁工程建设安全气候主要调查指标。研究确定的安全气候主要因子可以为地铁工程建设中安全气候问卷调查提供基础,并通过对安全效果的有效预测指导安全管理决策。 相似文献
67.
The Economic and Environmental Outcomes of Microfinance Projects: An Indian Case Study 总被引:1,自引:0,他引:1
Microfinance projects now seek to achieve improvement in environmental quality in addition to poverty alleviation. Achievement
of these goals may depend upon the economic and environmental impact of microfinance businesses. This study is a quantitative
analysis of these outcomes for Ecodevelopment, an Indian microfinance project, which aims to prevent forest degradation by
poverty alleviation. The study divides businesses into perishable goods, non-perishable goods, simple skills, and special
skills and measures their economic outcome by two indicators, repayment percentage and continuity of businesses. The study
examines the effect of loan amount on the economic outcome of businesses. To quantify the environmental outcome, it analyzes
the use of firewood or fodder and release of pollutants by businesses. The results show that loan amount does not affect the
economic outcome, special skills have best performance, and skills cause less pressure on forest resources. These results
suggest the need for development of knowledge-intensive skills, involvement of institutions in the operations of business,
and inclusive policies for protected area management. 相似文献
68.
通过对工程项目特点的分析和对参与项目建设当事人对工程质量安全的影响归因分析,认为,制度安排的缺陷及诚信文化缺失是我国建设工程质量安全事故频繁发生的根本原因。根据我国国情并借鉴国际工程保险的经验,笔者指出,专业保险公司介入建设工程项目监理,是弥补制度缺陷和诚信文化缺失、提高工程的质量安全系数的最佳选择。 相似文献
69.
ABSTRACT: The optimization of real-time operations for a single reservoir system is studied. The objective is to maximize the sum of hourly power generation over a period of one day subject to constraints of hourly power schedules, daily flow requirement for water supply and other purposes, and the limitations of the facilities. The problem has a nonlinear concave objective function with nonlinear concave and linear constraints. Nonlinear Duality Theorems and Lagrangian Procedures are applied to solve the problem where the minimization of the Lagrangian is carried out by a modified gradient projection technique along with an optimal stepsize determination routine. The dimension of the problem in terms of the number of variables and constraints is reduced by eliminating the 24 continuity equations with a special implicit routine. A numerical example is presented using data provided by the Bureau of Reclamation, Sacramento, California. 相似文献
70.
A conceptual model is developed herein for the purpose of stimulating discussions within groups planning and carrying out
integrated natural resource projects. We first describe four basic components of integrated planning and modeling efforts:
people, databases, technology, and organizational commitment. Second, we provide one view of the relationship between the
size of the project's decision-making body and the timing of decisions during a project's life cycle. Finally, these two discussions
are combined into a conceptual model describing the dynamic nature of decision-making within integrated projects. The abstractions
and generalizations described here are not unique to private industry or governmental organizations and should provide the
basis for a discussion of decision-making issues among interdisciplinary professionals embarking on large-scale or complex
modeling efforts. 相似文献