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181.
The results of the census of stray dogs and data on their territorial distribution in the city of Petrozavodsk are reported. The population density of these animals has been found to vary within the urban area, depending mainly on the availability of secluded areas to live in and on population control by municipal services.  相似文献   
182.
Application of harmonic analysis to daily mean air, water temperature records for a location indicates that the first harmonic accounts for a major portion of the total variance in the records. Water temperature residuals are well correlated with air temperature residuals. Parametric values of the mathematical model for predicting water temperatures from air temperature records are stable from year to year. The air-water temperature relationship appears to be a stationary linear process. Consequently, it is possible to predict water temperatures at a location from the ambient temperature records provided both air and water temperature records are available for another similarly situated water body.  相似文献   
183.
武进区花卉苗木基地产业生态化建设方案研究   总被引:3,自引:0,他引:3  
苏南地区的快速城市化在带动地方经济大发展的同时,却给农村环境造成了巨大的压力,如何实现农村环境与经济协调发展是亟待研究的任务。江苏省常州市武进区花卉苗木基地的实践表明,对区域做出科学的生态经济区划,在严格保护基本农田的基础上,充分利用其它类型的土地资源因地制宜地发展花卉苗木生态产业,成为农村生态环境建设的优化途径之一。武进花木基地环境建设包括:(1)优化生态经济区划,将整个基地划分为平原水网和漏湖圩田两个生态经济区;(2)根据各生态经济区的不同特点采取相应的生态产业布局和实施方案;(3)发展具有“水乡、花卉、休闲”特色的生态旅游产业。  相似文献   
184.
ABSTRACT: Regionalization of design storms can enhance their utility. Otherwise they have to be separately developed for different regions. Huff curves developed from point rainfall data collected at Coshocton, Ohio, and Chicago, Illinois, and from area-averaged Illinois and Texas precipitation data, are compared. The curves are similar in shape and position, with some visual differences depending on quartile. Kolmogorov-Smirnov tests showed no significant differences in moat of the comparisons. Where significant differences existed, they may not represent real differences due to the small number of storms sampled. Consequently, regionalization of Huff curves from Ohio to Illinois to Texas may be appropriate. The comparison of Huff curves is affected to an unknown degree both by the effects of area averaging of data and by basis. of-development differences. The effects of observed differences in Huff curves on watershed response variables (e.g., peak flow) requires further study.  相似文献   
185.
Much attention has been invested in the model choice problem for peak annual flows, in the context of flood frequency analysis. The authors would sidestep this dilemma through non-parametric density estimation methodology, but recognize that the standard nonparametric estimators preclude the use of prior information and related data, and furthermore have virtually no tail at all. Here we offer a remedy for these inadequacies by introducing an estimator which mixes parametric and nonparametric density estimates. We prove that our mixture rule is consistent. By this procedure, we do allow incorporation of prior information, experience, and regional data information, but nevertheless provide a safeguard against incorrect model choice.  相似文献   
186.
ABSTRACT: Two dimensional sliding polynomials were adapted to pattern analysis of watershed monthly rainfall and runoff. Contours of runoff in the two-dimensional space of time and rainfall are constructed on a grid of 16 nodes whose values are determined by least squares. This method is form free, hence derived patterns are not biased to selected functional forms, but can directly represent the smoothed data. Values of the nodes are localized averages of the data constrained by required mathematical continuity across the grid of values. An advantage of the method is that the standard deviation can be calculated for each node, thus producing patterns of uncertainty of the deterministic component revealed by the data.  相似文献   
187.
Sulphur dioxide (SO2) is one of the main atmospheric pollutants in central Taiwan. This article analyses the SO2 concentration seasonal variations and spatial distribution using data obtained from ten air quality monitoring stations and the Taiwan Weather Bureau. It reveals that SO2 concentration is high in winter and low in summer and that high concentration centers are located south of the Taichung coal-fired power plant, the main source of SO2 emissions in the region.The location of high concentration centers changeswith different prevailing winds. SO2 variations due towind direction are not unique. During short periods,when meteorological conditions are constant, variationin the pollution sources cause variations in thespatial distribution. This has been deduced byappreciation of Intervention analysis to time seriesof hourly data.  相似文献   
188.
Ozone biomonitoring is a detection and monitoring techniquethat involves documenting ozone-induced visible injury toknown ozone-sensitive species under conditions of ambientexposure. The USDA Forest Service administers a long-term,nationwide ozone biomonitoring program to address public andscientific concerns about ozone impacts on forest health. Asystematic grid is used as the basis for biomonitoring sitelocations. At each site, trained field crews evaluate amaximum of thirty plants of up to six species and record the amount and severity of leaf-injury on individualplants. Injury from ozone was found more often on biomonitoring sites in the eastern Unites States than in theinterior or west-coast areas. Further results from thenortheast reveal that in any year, there is a higherpercentage of ozone-injured plants with more severe symptomsin areas with relatively high ozone concentrations than inareas with relatively low ozone. In very dry years (e.g.,1999) the percentage of injured plants and injury severityestimates are both sharply reduced even though ambient ozoneexposures are high. These findings demonstrate thatbiomonitoring data provide meaningful evidence of when highozone concentrations during the growing season have biologicalsignificance. Any assessment of ozone stress in the forestenvironment must include both biomonitoring (i.e., plantresponse) and air quality data to be complete.  相似文献   
189.
曲靖市环境噪声达标规划   总被引:1,自引:0,他引:1  
对曲靖市城区进行了环境噪声功能区划分;分析了曲靖市噪声污染现状和趋势、噪声污染原因,对噪声污染结果进行了预测;分析了环境噪声达标规划,提出了噪声污染控制方案。  相似文献   
190.
利用静态箱-气相色谱法对鼎湖山3 种处于演替不同阶段的森林类型(季风常绿阔叶林、针阔叶混交林和马尾松林)的地表N2O 通量进行了 1 年的原位观测和研究.结果表明,3 种林型地表 N2O 通量按从大到小的顺序为:季风林>混交林>松林;不同林型间的 N2O 通量差异与森林土壤的性质有密切关系,C/N 比值较低的季风林凋落叶对土壤中产生N2O 的微生物过程有较为明显的促进作用;从全年来看,松林地表N2O 通量的季节变化不明显,而季风林和混交林的地表 N2O 通量在雨季存在明显的降雨驱动效应,统计分析显示在该地区影响森林地表N2O 通量的主要因子是土壤湿度.  相似文献   
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