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151.
通过四明山红色旅游目的地开发建设的优势、机遇及劣势与挑战的分析,提出了开发与建设四明山红色旅游目的地的六大策略,即政府主导与市场运作相结合的开发策略、社会效益和经济效益兼顾的开发策略、红色旅游目的地品牌策略、"红绿结合"的开发策略、区域合作策略、基于和谐旅游发展的开发策略。  相似文献   
152.
A forest ecological inventory and monitoring system combining information derived from maps and samples is proposed based on ecosystem regions (Bailey, 1994). The system extends the design of the USDA Forest Service Region 6 Inventory and Monitoring System (R6IMS) in the Pacific Northwest of the United States. The key uses of the information are briefly discussed and expected results are illustrated with examples. The system is flexible, allowing regions based on ecological considerations to be modified. Sampling intensities that are affordable are likely to be insufficient to provide meaningful estimates for key parameters relating to rare and endangered species, watersheds, and other ecological units. Methods are proposed for collecting additional information in follow-up surveys and combining it with relevant information obtained in R6IMS. Near-continuous information on weather and possible pollution variables recorded by instruments at sampling sites is needed to develop meaningful models to understand what is happening in the ecoregions. R6IMS and the proposed additions constitute a dynamic system which will be modified further as data are analyzed.  相似文献   
153.
Restricted adaptive cluster sampling   总被引:4,自引:0,他引:4  
Adaptive cluster sampling can be a useful design for sampling rare and patchy populations. With this design the initial sample size is fixed but the size of the final sample (and total sampling effort) cannot be predicted prior to sampling. For some populations the final sample size can be quite variable depending on the level of patchiness. Restricted adaptive cluster sampling is a proposed modification where a limit is placed on the sample size prior to sampling and quadrats are selected sequentially for the initial sample size. As a result there is less variation in the final sample size and the total sampling effort can be predicted with some certainty, which is impor- tant for many ecological studies. Estimates of density are biased with the restricted design but under some circumstances the bias can be estimated well by bootstrapping. © Rapid Science 1998  相似文献   
154.
Composite sampling techniques for identifying the largest individual sample value seem to be cost effective when the composite samples are internally homogeneous. However, since it is not always possible to form homogeneous composite samples, these methods can lead to higher costs than expected. In this paper we propose a two-way composite sampling design as a way to improve on the cost effectiveness of the methods available to identify the largest individual sample value.  相似文献   
155.
生物资源在减轻农业草害中的作用与技术对策   总被引:1,自引:0,他引:1  
论述了生物资源在减轻农业草害和促进农业可持续发展中所具有的生态效益和经济效益,提出了开发生物资源防治农业草害的技术对策。  相似文献   
156.
博物馆室内微环境中碱性气体的被动采样方法研究   总被引:3,自引:1,他引:2  
针对博物馆微环境中的碱性污染气体-氨气,采用自行研制的被动采样器,建立了一套适合博物馆馆藏文物保存环境中氨气含量分析的被动采样-离子色谱检测方法,应用于博物馆的实地采样分析,通过与主动法采样对照,获得了被动采样器在博物馆微环境中氨的吸收系数,从而获得采样点空气中氨气的浓度,为博物馆文物保存环境监测提供了可行方法。  相似文献   
157.
Studies on quantitative soil contamination due to heavy metals were carried out in Katedan Industrial Development Area (KIDA), south of Hyderabad, Andhra Pradesh, India under the Indo-Norwegian Institutional Cooperation Programme. The study area falls under a semi-arid type of climate and consists of granites and pegmatite of igneous origin belonging to the Archaean age. There are about 300 industries dealing with dyeing, edible oil production, battery manufacturing, metal plating, chemicals, etc. Most of the industries discharge their untreated effluents either on open land or into ditches. Solid waste from industries is randomly dumped along roads and open grounds. Soil samples were collected throughout the industrial area and from downstream residential areas and were analysed by X-ray Fluorescence Spectrometer for fourteen trace metals and ten major oxides. The analytical data shows very high concentrations of lead, chromium, nickel, zinc, arsenic and cadmium through out the industrial area. The random dumping of hazardous waste in the industrial area could be the main cause of the soil contamination spreading by rainwater and wind. In the residential areas the local dumping is expected to be the main source as it is difficult to foresee that rain and wind can transport the contaminants from the industrial area. If emission to air by the smokestacks is significant, this may contribute to considerable spreading of contaminants like As, Cd and Pb throughout the area. A comparison of the results with the Canadian Soil Quality Guidelines (SQGL) show that most of the industrial area is heavily contaminated by As, Pb and Zn and local areas by Cr, Cu and Ni. The residential area is also contaminated by As and some small areas by Cr, Cu, Pb and Zn. The Cd contamination is detected over large area but it is not exceeding the SQGL value. Natural background values of As and Cr exceed the SQGL values and contribute significantly to the contamination in the residential area. However, the availability is considerably less than anthropogenic contaminants and must therefore be assessed differently. The pre- and post-monsoon sampling over two hydrological cycles in 2002 and 2003 indicate that the As, Cd and Pb contaminants are more mobile and may expect to reach the groundwater. The other contaminants seem to be much more stable. The contamination is especially serious in the industrial area as it is housing a large permanent residing population. The study not only aims at determining the natural background levels of trace elements as a guide for future pollution monitoring but also focuses on the pollution vulnerability of the watershed. A plan of action for remediation is recommended.  相似文献   
158.
采用碱片-离子色谱法测定空气的硫酸盐化速率,方法在硫酸盐质量浓度为1.00~20.0 mg/L范围内线性良好(r≥0.999 0);碱片剪碎或不剪碎对空白碱片中硫酸根离子质量浓度的测定无明显影响,且高低两种加标浓度的回收率均在80.0%~120%之间;对于碱片实际样品,碱片剪碎更有利于硫酸根离子的快速溶出;随浸泡时间的延长,碱片中溶出的硫酸根离子质量浓度呈上升趋势,7 h硫酸根离子基本溶出完全,从保证结果质量和节省时间的角度考虑,确定最佳浸泡时间为3.5 h,建议碱片全部采取剪碎处理。  相似文献   
159.
针对生活垃圾焚烧企业烟气排放烟囱6个断面单点采样的试验结果,分析按照《固定污染源排气中颗粒物测定与气态污染物采样方法》(GB/T 16157—1996)多断面点采样与单一固定断面点采样对监测结果的影响。试验表明,烟道气在不同断面点质量浓度分布差异较大,相对于样品实际监测值,各断面点二噁英毒性当量浓度最大正偏差达到+306%,最大负偏差达到-96%,测定的18个断面点样品,只有2个样品与实际样品监测值相近。  相似文献   
160.
Land managers need better techniques to assess exoticplant invasions. We used the cross-correlationstatistic, I YZ, to test for the presence ofspatial cross-correlation between pair-wisecombinations of soil characteristics, topographicvariables, plant species richness, and cover ofvascular plants in a 754 ha study site in RockyMountain National Park, Colorado, U.S.A. Using 25 largeplots (1000 m2) in five vegetation types, 8 of 12variables showed significant spatial cross-correlationwith at least one other variable, while 6 of 12variables showed significant spatial auto-correlation. Elevation and slope showed significant spatialcross-correlation with all variables except percentcover of native and exotic species. Percent cover ofnative species had significant spatialcross-correlations with soil variables, but not withexotic species. This was probably because of thepatchy distributions of vegetation types in the studyarea. At a finer resolution, using data from ten1 m2 subplots within each of the 1000 m2 plots, allvariables showed significant spatial auto- andcross-correlation. Large-plot sampling was moreaffected by topographic factors than speciesdistribution patterns, while with finer resolutionsampling, the opposite was true. However, thestatistically and biologically significant spatialcorrelation of native and exotic species could only bedetected with finer resolution sampling. We foundexotic plant species invading areas with high nativeplant richness and cover, and in fertile soils high innitrogen, silt, and clay. Spatial auto- andcross-correlation statistics, along with theintegration of remotely sensed data and geographicinformation systems, are powerful new tools forevaluating the patterns and distribution of native andexotic plant species in relation to landscape structure.  相似文献   
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