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排序方式: 共有993条查询结果,搜索用时 93 毫秒
221.
乌鲁木齐市与北方四城市的空气污染对比及原因分析 总被引:6,自引:1,他引:6
根据乌鲁木齐、兰州、太原、石家庄和北京五大北方城市的空气污染特征,结合各城市人口、经济和地理位置等要素,分析了乌鲁木齐市与其它城市空气污染及成因的主要异同点,对目前乌鲁木齐市大气污染治理中的若干问题进行了探讨。 相似文献
222.
Despite much discussion about the utility of remote sensing for effective conservation, the inclusion of these technologies in species recovery plans remains largely anecdotal. We developed a modeling approach for the integration of local, spatially measured ecosystem functional dynamics into a species distribution modeling (SDM) framework in which other ecologically relevant factors are modeled separately at broad scales. To illustrate the approach, we incorporated intraseasonal water-vegetation dynamics into a cross-scale SDM for the Common Snipe (Gallinago gallinago), which is highly dependent on water and vegetation dynamics. The Common Snipe is an Iberian grassland waterbird characteristic of European agricultural meadows and a member of one of the most threatened bird guilds. The intraseasonal dynamics of water content of vegetation were measured using the standard deviation of the normalized difference water index time series computed from bimonthly images of the Sentinel-2 satellite. The recovery plan for the Common Snipe in Galicia (northwestern Iberian Peninsula) provided an opportunity to apply our modeling framework. Model accuracy in predicting the species’ distribution at a regional scale (resulting from integration of downscaled climate projections with regional habitat–topographic suitability models) was very high (area under the curve [AUC] of 0.981 and Boyce's index of 0.971). Local water-vegetation dynamic models, based exclusively on Sentinel-2 imagery, were good predictors (AUC of 0.849 and Boyce's index of 0.976). The predictive power improved (AUC of 0.92 and Boyce's index of 0.98) when local model predictions were restricted to areas identified by the continental and regional models as priorities for conservation. Our models also performed well (AUC of 0.90 and Boyce's index of 0.93) when projected to updated water-vegetation conditions. Our modeling framework enabled incorporation of key ecosystem processes closely related to water and carbon cycles while accounting for other factors ecologically relevant to endangered grassland waterbirds across different scales, allowed identification of priority areas for conservation, and provided an opportunity for cost-effective recovery planning by monitoring management effectiveness from space. 相似文献
223.
A. G. Coon 《Journal of Environmental Planning and Management》1989,32(2):77-85
The present development plan system in Scotland began in 1975. Its origins and purpose are discussed. Progress in the submission and adoption/approval of local and structure plans and in reviewing these plans is outlined. Performance to date is assessed and means of improvement are suggested, in relation to timeliness, transparency, scope and quality. 相似文献
224.
Bryan H. Massam 《Journal of the American Water Resources Association》1984,20(4):483-491
ABSTRACT The Central Arizona Water Control Study (CAWCS) was initiated by the Bureau of Reclamation in 1978. The study attempted to identify and evaluate alternate water management schemes for Central Arizona. By 1981 a set of seven plans had been developed and for each an assessment on a number of economic, environmental, and social factors had been undertaken. This paper offers a formal procedure, using concordance analysis and multi-dimension scaling, to compare alternate plans using multiple factors in order to produce a classification of the attractiveness of the alternatives. Empirical data for the CAWCS are used to clarify the procedure. The results of the formal analysis are compared to those produced by the CAWCS. A critique of the formal procedure is offered, and it is suggested that it may have utility to assist in the collection of data as well as in the search for a best plan. The procedure allows a number of different types of sensitivity tests to be conducted. 相似文献
225.
中国农村人口问题与中国可持续发展 总被引:17,自引:0,他引:17
中国人口问题是中国可持续发展面临的首要问题。中国13亿人口中约有9亿是农村人口。因此所谓“中国人口问题”根本上是中国农村人口问题。人口为什么会成为一个“问题”则是关注的焦点。通过对人口问题本质进行剖析发现。研究人口问题必须着眼予人与自然的关系以及人与社会的关系。而解决中国的人口“问题”则必须着眼于农村人口生存方式的改变。从当前我国农村人口的生存方式和状况来看。中国的农村人口问题折射在农业、农村问题上。故统称为“三农”问题。为此,着眼于中国可持续发展提出解决中国农村人口问题的途径和建议。 相似文献
226.
Zimbabwean provincial plans were instituted to help in the achievement of the national goal of the creation of an egalitarian, socialist and integrated society. The national goal itself was adopted as an antithesis to the dualist society characterised by spatial, economic, social, politican and technological inequalities that Zimbabwe inherited from colonialism. This meant that provincial plans had to play both a functional (or growth allocating/distribution) and a territorial (or redistribution) role.
This paper reviews their role in achieving the national goal by examining their functions, content, structure and methodology. The paper concludes that because of their nature, provincial plans are not suitable tools for the achievement of the national goal. 相似文献
227.
228.
为了保障香港市民的身体健康,保护鱼类及其他海洋生物并提高维多利亚港的水质,必须对香港的150万m3/d污水采取处理措施,介绍了策略性污水排放计划的产生及一期工程的进展情况. 相似文献
229.
自然保护区生态旅游开发及保护规划探讨——以武夷山自然保护区为例 总被引:3,自引:0,他引:3
对自然保护区生态旅游开发意义和特点进行阐述,并以武夷山自然保护区为例,探讨如何制订自然保护区生态旅游保护规划,提出管理监控的内容和方法。 相似文献
230.
尹韶青 《防灾技术高等专科学校学报》2005,7(4):17-20
本项目旨在通过开发公共场所火灾事故应急预案编辑平台与管理系统,使公共场所火灾事故应急预案的编写和管理简单化、规范化、科学化,以提高预案制定人员的工作效率。 相似文献