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Citizen science may be especially effective in urban landscapes due to the large pool of potential volunteers. However, there have been few evaluations of the contributions of citizen scientists to knowledge of biological communities in and around cities. To assess the effectiveness of citizen scientists' monitoring of species in urban areas, we compared butterfly data collected over 10 years in Chicago, Illinois (U.S.A.), and New York City, New York (U.S.A.). The dates, locations, and methods of data collection in Chicago were standardized, whereas data from New York were collected at any location at any time. For each city, we evaluated whether the number of observers, observation days (days on which observations were reported), and sampling locations were associated with the reported proportion of the estimated regional pool of butterfly species. We also compared the number of volunteers, duration of volunteer involvement, and consistency of sampling efforts at individual locations within each city over time. From 2001 to 2010, there were 73 volunteers in Chicago and 89 in New York. During this period, volunteers observed 86% and 89% of the estimated number of butterfly species present in Chicago and New York, respectively. Volunteers in New York reported a greater proportion of the estimated pool of butterfly species per year. In addition, more species were observed per volunteer and observation day in New York, largely due to the unrestricted sampling season in New York. Chicago volunteers were active for more years and monitored individual locations more consistently over time than volunteers in New York. Differences in monitoring protocol--especially length of sampling season and selection protocol for monitoring locations--influenced the relationship between species accrual and sampling effort, which suggests these factors are important in volunteer-based species-monitoring programs. 相似文献
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Field experiments were carried out in the vicinity of anisolated building using open-path and point monitoring airpollution detectors to measure concentrations of a tracer gasreleased from a source located either on the building or at thedownwind face of the building. Experiments were conducted underneutral or slightly unstable weather conditions. Either threeor five fast-response point monitors were located along thebeam path of an open-path instrument, in the wake of thebuilding. Experiments were performed with different sourcelocations, detector locations and building orientations to thewind. Visual comparison of data time series showed that datafrom the two types of instruments followed similar trends. Thebest degree of correlation occurred for an averaging timesimilar to the response time of the open-path monitor. Meanconcentrations detected by the open-path instrument weregenerally in very good agreement with the path averaged meanconcentrations from the point monitors. The point monitors werealso capable of providing time-resolved data needed to describedetailed concentration fluctuation statistics. 相似文献
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Casanovas R Morant JJ López M Hernández-Girón I Batalla E Salvadó M 《Journal of environmental radioactivity》2011,102(8):742-748
The automatic real-time environmental radiation surveillance network of Catalonia (Spain) comprises two subnetworks; one with 9 aerosol monitors and the other with 8 Geiger monitors together with 2 water monitors located in the Ebre river. Since September 2006, several improvements were implemented in order to get better quality and quantity of data, allowing a more accurate data analysis. However, several causes (natural causes, equipment failure, artificial external causes and incidents in nuclear power plants) may produce radiological measured values mismatched with the own station background, whether spurious without significance or true radiological values. Thus, data analysis for a 50-month period was made and allowed to establish an easily implementable statistical criterion to find those values that require special attention. This criterion proved a very useful tool for creating a properly debugged database and to give a quick response to equipment failures or possible radiological incidents. This paper presents the results obtained from the criterion application, including the figures for the expected, raw and debugged data, percentages of missing data grouped by causes and radiological measurements from the networks. Finally, based on the discussed information, recommendations for the improvement of the network are identified to obtain better radiological information and analysis capabilities. 相似文献
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