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171.
陕西未来50年区域旱涝气候预测研究 总被引:7,自引:0,他引:7
用陕西省近526a的旱涝等级资料,根据超低频气候振动理论和尺度对应原理,通过旱涝气候对天体物理、太阳活动等周期,特别是ENSO对天体物理显著敏感的周期响应关系的物理统计分析,选取周期概率显著的周期,进行外延叠加集成预测,给出了未来50a陕西省不同区域旱涝趋势的预测结果. 相似文献
172.
苏州河水量水质预报模型研究 总被引:8,自引:0,他引:8
根据建立的一维非恒定流水量模型和一维非稳态水质模型,定量预测苏州河在截污工程实施前后的水量和水质变化规律,探讨进一步改善苏州河水环境的措施。 相似文献
173.
公路汽车尾气扩散模式研究 总被引:6,自引:0,他引:6
通过实测资料和理论计算的对比分析,认为在有风条件下对源参数作适当修正后,可以利用线源模式预测公路汽车尾气扩散浓度分布,同时提出了适合高速公路汽车尾气扩散浓度预测的源参数修正方法,可供高速公路环境影响评价时参考。 相似文献
174.
Applications of artificial neural networks for patterning and predicting aquatic insect species richness in running waters 总被引:3,自引:0,他引:3
Two artificial neural networks (ANNs), unsupervised and supervised learning algorithms, were applied to suggest practical approaches for the analysis of ecological data. Four major aquatic insect orders (Ephemeroptera, Plecoptera, Trichoptera, and Coleoptera, i.e. EPTC), and four environmental variables (elevation, stream order, distance from the source, and water temperature) were used to implement the models. The data were collected and measured at 155 sampling sites on streams of the Adour–Garonne drainage basin (South-western France). The modelling procedure was carried out following two steps. First, a self-organizing map (SOM), an unsupervised ANN, was applied to classify sampling sites using EPTC richness. Second, a backpropagation algorithm (BP), a supervised ANN, was applied to predict EPTC richness using a set of four environmental variables. The trained SOM classified sampling sites according to a gradient of EPTC richness, and the groups obtained corresponded to geographic regions of the drainage basin and characteristics of their environmental variables. The SOM showed its convenience to analyze relationships among sampling sites, biological attributes, and environmental variables. After accounting for the relationships in data sets, the BP used to predict the EPTC richness with a set of four environmental variables showed a high accuracy (r=0.91 and r=0.61 for training and test data sets respectively). The prediction of EPTC richness is thus a valuable tool to assess disturbances in given areas: by knowing what the EPTC richness should be, we can determine the degree to which disturbances have altered it. The results suggested that methodologies successively using two different neural networks are helpful to understand ecological data through ordination first, and then to predict target variables. 相似文献
175.
对齐齐哈尔市经济发展和主要污染物排放趋势进行了预测,并对面临的环境压力、环境质量主要问题和影响环境质量的污染原因进行了分析。该文对为我市各级政府和环境管理部门的决策提供科学依据。 相似文献
176.
Logistic回归模型在尘肺发病预测与控制中的应用研究 总被引:4,自引:1,他引:3
目的 :探讨 L ogistic回归模型在尘肺发病预测与控制中的应用。方法 :采用多元Logistic回归统计方法建立粉尘作业工人的接尘工龄 (ET)、工龄平均浓度 (AEC)、粉尘毒性 (T)三因素与尘肺发病概率的回归模型。结果 :尘肺发病预测与控制的回归模型为 :P=1/ { 1+ exp[- (- 5.4 70 7+ 0 .0 94 7ET+ 0 .0 0 2 4 AEC+ 1.9784 T) ]} ,接尘工龄等三因素对尘肺发病影响的比数比分别为 :1.0 994 (ET)、1.0 0 2 4 (AEC)和 7.2 310 (T)。结论 :所建立尘肺发病预测与控制的回归模型与所研究人群的符合率较高 ,对今后预防尘肺发生的科学化管理与决策有较好的实用性和应用价值。 相似文献
177.
用灰色建模法预测矿井瓦斯涌出量 总被引:13,自引:4,他引:9
在分析了传统的矿井瓦斯涌出量预测方法的基础上 ,应用灰色系统理论 GM(1,1)模型 ,对矿井瓦斯涌出量进行预测 ,并在实际中得到了较好的验证。 相似文献
178.
A simple method for predicting the consequences of land management in urban habitats 总被引:2,自引:0,他引:2
Land management in urban areas is characterized by the diversity of its goals and its physical expression in the landscape,
as well as by the frequency and often rapidity of change. Deliberate or accidental landscape alterations lead to changes in
habitat, some of which may be viewed as environmentally beneficial, others as detrimental. Evaluating what is there and how
changes may fit into the landscape context is therefore essential if informed land-management decisions are to be made.
The method presented here uses a simple ecological evaluation technique, employing a restricted number of evaluation criteria,
to gather a spatially complete data set. A geographical information system (GIS) is then used to combine the resulting scores
into a habitat value index (HVI). Using examples from Wolverhampton in the United Kingdom, existing real-world data are then
applied to land-management scenarios to predict probable landscape ecological consequences of habitat alteration.
The method provides an ecologically relevant, spatially complete evaluation of a large, diverse area in a short period of
time. This means that contextual effects of land-management decisions can be quickly visualized and remedial or mitigating
measures incorporated at an early stage without the requirement for complex modeling and prior to the detailed ecological
survey. The strengths of the method lie in providing a detailed information baseline that evaluates all habitats, not just
the traditional “quality” habitats, in a manner that is accessible to all potential users—from interested individuals to professional
planners. 相似文献
179.
本文论述了本世纪以来,地质灾害防治现状:1.无预报、无预防;2.有预报而无预防;3.有预报、有预防方案而没有实施;4.有预报、有预防方案并组织实施。最后,提出减轻地质灾害8条对策。 相似文献
180.
Importance of insects in environmental impact assessment 总被引:9,自引:0,他引:9
Insects are particularly suited for use in environmental impact assessment (e.i.a.) because of their high species diversity, ubiquitous occurrence, and importance in the functioning of natural ecosystems. Examples are given of the use of insects in the predictive phase of e.i.a., in the monitoring and assessment phase, and in the much rarer instance of an e.i.a. that includes both of these phases. The importance of working at the species level to understanding the results of e.i.a. is emphasized. 相似文献