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901.
为提高煤矿防治水管理水平,预防和消除矿井水害,在层次分析法的基础上建立中性值作为参照对象对矿井水害风险进行实时评判的方法。根据《煤矿防治水细则》建立以矿井水文地质类型、矿井涌水量标准分数、突水预兆、采掘面位置、探水结果为准则层的层次结构模型,并对各评价指标赋权。依据制定的水害风险评价指标的评分细则和监测监控数据并结合其权重得到水害评价总得分。通过总得分与中性参照分数比较得出预测结果:水害评价总得分大于中性参照分数,证明水害的威胁小,分数越高越安全;反之则水害的威胁较大,分数越低越危险,这时需要加强防治水的力度,令评价分数管控大于中性参照分数。这种方法依赖于井下监测监控数据进行量化评价,能实时、客观、全面且准确地反映煤矿水害的风险情况。 相似文献
902.
为了研究波浪与抛石潜堤相互作用过程中大自由表面变形和堤内渗流等强非线性紊流运动问题,利用改进的MPS法,建立了模拟波浪与抛石潜堤相互作用的MPS法数值计算模型。模型将抛石潜堤假定为均质多孔介质,采用Drew的二相流运动方程描述多孔介质内外的流体运动;通过在动量方程中增加非线性阻力项,并引入亚粒子尺度紊流模型,模拟波浪与可渗结构物相互作用过程中的紊流运动。选取“U”型管中多孔介质内渗流过程和孤立波与可渗潜堤相互作用两个典型的渗流问题,通过将数值计算结果与理论解和实测值的对比分析,对所提出的MPS法紊流渗流模型的模拟精度进行验证。结果表明:基于改进的MPS法构建的垂向二维紊流渗流模型可以很好地再现 “U”型管中多孔介质内渗流以及波浪作用下可渗潜堤内外的复杂流场,显著缓解流-固界面处的压力震荡与粒子分布不均匀问题,实现了较高的模拟精度。 相似文献
903.
Yapeng Song Hui Gong Jianbing Wang Fengmin Chang Kaijun Wang 《Frontiers of Environmental Science & Engineering》2020,14(4):64
904.
Chaojin Jiang Xiaoqian Jiang Lixun Zhang Yuntao Guan 《Frontiers of Environmental Science & Engineering》2020,14(3):47
905.
Mona Akbar Muhammad Farooq Saleem Khan Ling Qian Hui Wang 《Frontiers of Environmental Science & Engineering》2020,14(6):98
906.
Zhen Bi Deqing Wanyan Xiang Li Yong Huang 《Frontiers of Environmental Science & Engineering》2020,14(3):38
907.
908.
Chou CJ 《Environmental monitoring and assessment》2006,119(1-3):571-598
Statistical analyses were applied at the Hanford Site, USA, to assess groundwater contamination problems that included (1) determining local backgrounds to ascertain whether a facility is affecting the groundwater quality and (2) determining a ‘pre-Hanford' groundwater background to allow formulation of background-based cleanup standards. The primary purpose of this paper is to extend the random effects models for (1) assessing the spatial, temporal, and analytical variability of groundwater background measurements; (2) demonstrating that the usual variance estimate s
2, which ignores the variance components, is a biased estimator; (3) providing formulas for calculating the amount of bias; and (4) recommending monitoring strategies to reduce the uncertainty in estimating the average background concentrations. A case study is provided. Results indicate that (1) without considering spatial and temporal variability, there is a high probability of false positives, resulting in unnecessary remediation and/or monitoring expenses; (2) the most effective way to reduce the uncertainty in estimating the average background, and enhance the power of the statistical tests in general, is to increase the number of background wells; and (3) background for a specific constituent should be considered as a statistical distribution, not as a single value or threshold. The methods and the related analysis of variance tables discussed in this paper can be used as diagnostic tools in documenting the extent of inherent spatial and/or temporal variation and to help select an appropriate statistical method for testing purposes. 相似文献
909.
Sargaonkar A 《Environmental monitoring and assessment》2006,117(1-3):491-503
Non-point source (NPS) pollution is the result of various land use practices such as agriculture, sites of construction and
waste disposal, urban development and so on. The control of NPS pollution is possible by regular monitoring and assessment
on watershed basis to educate people for implementing well-known structural and non-structural measures. Recent trend is to
use GIS based modelling tool for assessment of rainfall-runoff and non-point loading. The approach requires generation and
analysis of basin wide data on various features of land and estimates of Event Mean Concentrations (EMCs) of pollutants in
the runoff. In the present paper, basin wide data in different districts of Tapi basin has been analysed for land use distribution;
fertilizer application; low, medium and high-density habitation; and annual rainfall. Coefficients of runoff have been estimated
considering pervious and impervious area for different land use types, and compared with the reported values for Indian conditions.
The estimated mean annual runoff flow indicated that two districts Jalgaon and Dhule contribute maximum runoff to the Tapi
River. Estimates of EMCs for BOD and nutrients (N and P) in the runoff from various districts are useful in GIS-based modelling
study for NPS pollution assessment. 相似文献
910.
The Atlantic Coastal Action Program (ACAP) is a unique, community-based program initiated by Environment Canada in 1991 to help Atlantic Canadians restore and sustain watersheds and adjacent coastal areas. ACAP is the eastem-most Environment Canada Ecosystem Initiative. The ACAP family is currently made up of 14 ecosystem-based organizations in the four Atlantic provinces. Each one of these non-profit organizations operates independently, but is formally linked under the umbrella of ACAP to represent a force stronger than the individual parts. In Environment Canada's experience, the program consistently demonstrates the value of a community-based approach and produces results on an ecosystem basis. This paper will examine some of the impacts of ACAP in terms of economics, credible community science, and environmental results which most often align with Environment Canada's objectives. It will explore the influences of the community-based approach to environmental management on multiple scales (local, regional, etc.). Through examples, the paper will demonstrate the effectiveness of ACAP in influencing some of the policies, programs and attitudes of various levels of government and industry in the region, as well as describe how the community-based model has been exported internationally. The paper will conclude with a discussion on a planned path forward for ACAP. 相似文献