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891.
Carita Aschan Mikko Hirvonen Erkki Rajamäki Tarmo Mannelin Johanna Ruotsalainen Reija Ruuhela 《Safety Science》2009,47(8):1195-1200
In Finland about 70,000 people are annually injured in pedestrian and bicycle falling accidents occurred at the street, walkways and courtyards. Around 2/3 of these occur when the walking surface is covered by ice or snow. In general, slipping is caused by both environmental and human factors. The primary environmental factor behind slipping accidents is slip resistance characteristics of underfoot surface. Especially in winter slipping accidents are mainly due to inadequate friction between footwear and underfoot surfaces. Portable devices measuring friction, i.e. slipmeters, may be used for assessing slipperiness on different walking surfaces in situ. During winter seasons 2003 and 2004 a study was performed to evaluate the usability of portable slip simulator for measuring slipperiness of walkways on varying weather conditions and to assess slip resistance of different footwear. The Portable Slip Simulator proved to be applicable for measuring in situ the slipperiness of wintry walking surfaces and evaluating quality of winter maintenance. Significant differences in traction between footwear were found especially in normal Finnish climate winter days when friction provided by slip-resistant footwear was multifold compared to a poorer one. On very slippery icy surfaces no footwear provided enough grip and, therefore, in such conditions anti-slip devices should be used. 相似文献
892.
Past changes and possible future variations in the nature of extreme precipitation and flood events in Central Europe and
the Alpine region are examined from a physical standpoint. An overview is given of the following key contributory physical
processes: (1) the variability of the large-scale atmospheric flow and the associated changes of the North-Atlantic storm
track; (2) the feedback process between climate warming and the water cycle, and in particular the potential for more frequent
heavy precipitation events; and (3) the catchment-scale hydrological processes associated with variations in major river flooding
events and that are related to land-use changes, river training measures, and shifts in the proportion of rain to snowfall.
In this context an account is provided of the possible future forecasting and warning methodologies based upon high-resolution
weather prediction and runoff models. Also consideration is given to the detectability of past (future) changes in observed
(modeled) extreme events. It is shown that their rarity and natural fluctuation largely impedes a detection of systematic
variations. These effects restrict trend analysis of such events to return periods of below a few months. An illustration
using daily precipitation from the Swiss Alps does yield evidence for pronounced trends of intense precipitation events (return
period 30 days), while trends of stronger event classes are not detectable (but nevertheless can not be excluded). The small
detection probability for extreme events limits possible mitigation of future damage costs through an abatement of climate
change alone, and points to the desirability of developing improved early forecasting/warning systems as an additional no-regret
strategy.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
893.
Ali-Khodja H Belaala A Demmane-Debbih W Habbas B Boumagoura N 《Environmental monitoring and assessment》2008,138(1-3):219-231
Total suspended particulate matter and deposition fluxes of particles were investigated in the town of Didouche Mourad which
is located 13 km north of Constantine. Samples of air particulate matter were collected at one site located in the heart of
the town and situated 3 km north of a cement plant. Samples were collected from 2 November 2002 to 28 April 2003 every 3 days
using a high volume air sampler. Sampling intervals were 24 h in all cases. During the same period, samples of dust fallout
were collected at the same site. Samples were collected at 30-day intervals. Lead, chromium, manganese, nickel, copper, cobalt
and cadmium deposition fluxes were measured and both the soluble and insoluble fractions were determined. Furthermore, the
information gathered by this study was correlated with the corresponding hourly weather data provided by a weather station
installed at the study station. The possible sources for dust and trace metals were analyzed by comparing average contributions
of wind aspects to the concentrations and depositions of mass and chemical species with the average frequencies of wind direction.
The mean concentration was 300 μg/m3. The average dust deposition rate through the period of study was 221 mg/(m2.day). Results indicate that anthropogenic sources contribute greatly to trace elements. An exposure assessment to the heavy
metals taking into account the inhalation route and soil dust ingestion was carried out and allowed direct comparison of trace
metal intakes via these routes. 相似文献
894.
Schaefer CE do Amaral EF de Mendonça BA Oliveira H Lani JL Costa LM Fernandes Filho EI 《Environmental monitoring and assessment》2008,140(1-3):279-289
The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even
at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL
project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of
intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones:
Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The
highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the
high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed
to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus
lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow
soils from the Roraima and Rondonia highlands. A consistent east–west decline in biomass carbon in the Rio Negro Basin sector
is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of
sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable
capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high
C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed
to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need
for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting
C stocks in Amazonia when such great pedological variability is not taken into account. 相似文献
895.
Foran J. Brosnan T. Connor M. Delfino J. DePinto J. Dickson K. Humphrey H. Novotny V. Smith R. Sobsey M. Stehman S. 《Environmental monitoring and assessment》2000,62(2):147-167
The International Life SciencesInstitute (ILSI) Risk Science Institute (RSI) convenedan expert panel of scientists to developrecommendations for a comprehensive monitoring programfor the Croton and Catskill/Delaware watersheds, whichprovide drinking water to New York City's residents. This effort was conducted as part of efforts topreserve and enhance the quality of New York City'sreservoir system through a watershed protectionprogram. The panel developed recommendations for astrategic framework on which to construct a monitoringprogram. As part of this activity, the paneldetermined whether existing monitoring activities weredeficient and, where activities were deficient, thepanel developed recommendations for additionalinformation that should be collected.The panel recommended the development and use of anintegrated approach to watershed monitoring, whichdraws on modeling, risk-based planning and analysis,statistical sampling and design, and basic compliancemonitoring. The approach should be designed toprovide an assessment of natural and anthropogenicsources of stress to the system as well as anassessment of water quality trends in response tostresses acting in concert, both over the long termand over the five-year New York City Memorandum ofAgreement (MOA) assessment time frame. It should alsoprovide an assessment of the human health andenvironmental risks posed by a variety of stressors,and the impact of management actions implemented toameliorate stressors. 相似文献
896.
K. Bruce Jones Anne C. Neale Maliha S. Nash Kurt H. Riitters James D. Wickham Robert V. O'Neill Rick D. van Remortel 《Environmental monitoring and assessment》2000,63(1):159-174
Using a new set of landscape indicator data generated by the U.S.EPA, and a comprehensive breeding bird database from the National Breeding Bird Survey, we evaluated associations between breeding bird richness and landscape characteristics across the entire mid-Atlantic region of the United States. We evaluated how these relationships varied among different groupings (guilds) of birds based on functional, structural, and compositional aspects of individual species demographics. Forest edge was by far the most important landscape attribute affecting the richness of the lumped specialist and generalist guilds; specialist species richness was negatively associated with forest edge and generalist richness was positively associated with forest edge. Landscape variables (indicators) explained a greater proportion of specialist species richness than the generalist guild (46% and 31%, respectively). The lower value in generalists may reflect finer-scale distributions of open habitat that go undetected by the Landsat satellite, open habitats created by roads (the areas from which breeding bird data are obtained), and the lumping of a wide variety of species into the generalist category. A further breakdown of species into 16 guilds showed considerable variation in the response of breeding birds to landscape conditions; forest obligate species had the strongest association with landscape indicators measured in this study (55% of the total variation explained) and forest generalists and open ground nesters the lowest (17% of the total variation explained). The variable response of guild species richness to landscape pattern suggests that one must consider species' demographics when assessing the consequences of landscape change on breeding birds. 相似文献
897.
898.
Adomako D Nyarko BJ Dampare SB Serfor-Armah Y Osae S Fianko JR Akaho EH 《Environmental monitoring and assessment》2008,141(1-3):165-175
Waters and sediments of Subin River, which flows through the industrial and commercial areas of Kumasi in the Ashanti region
of Ghana, were geochemically investigated to ascertain heavy metal pollution levels due to anthropogenic activities. The study
shows preoccupying pollution levels that constitute a threat to public and ecological systems. The waters of Subin River are
neutral to slightly basic, inferred from pH values of 6.89–7.65). Electric conductivity (EC) of the waters ranges from 822
to 1,821 μs/cm and the range of total dissolved solids (TDS) is from 409 to 913 mg/l. Toxic elements contents of sediments
and waters from 10 sites along the river were analysed by instrumental neutron activation analysis (INAA), and Al, As, Cd,
Cr, Cu and Zn were determined. The concentrations of Al, As, Cd, Cr, Cu and Zn in the waters range between 4.02–15.18, 0.007–0.16,
0.002–0.05, 0.001–0.019, 1.32–7.04 and 4.28–10.2 mg/l, respectively. The contamination factors (CF) computed for the elements
indicate that with the exception of sampling site S10, the sediments are polluted with Cd. Chromium contamination in the sediments
is observed at S6 and S7, where the CF values were 1.39 and 1.52, respectively. The pollution load indices (PLI) were low
(<1) and ranged from 0.14 to 0.75, suggesting that the overall sediment column of the river is not polluted. 相似文献
899.
A. Veldkamp P.H. Verburg K. Kok G.H.J. de Koning J. Priess A.R. Bergsma 《Environmental Modeling and Assessment》2001,6(2):111-121
This paper introduces some of the issues that are relevant to the spatially explicit modeling of land use systems. A short overview is given of the ways and means in which a number of different land use change models describe the land use system. Specific attention is given to the empirical modeling approach used in the CLUE (Conversion of Land Use and its Effects) modeling framework. This approach is demonstrated for three case studies in China, Ecuador and the Atlantic Zone of Costa Rica. These case-studies illustrate the methodology for multi-scale analysis of land use driving factors and their application in spatially explicit modeling exercises. Model functioning, performance and limitations are discussed. The presented case-studies indicate that empirical modeling results can contribute to a better theoretic imbedding of land use change research in scale sensitive and integrated theories. 相似文献
900.
Majagi SH Vijaykumar K Vasanthkaumar B 《Environmental monitoring and assessment》2008,138(1-3):273-279
In this study, some heavy metals concentrations (Zn, Pb, Fe, Mn, Cu, Ni) and other physico-chemical parameters were studied
during October 2001 to September 2003 in Karanja reservoir, Bidar district. Water quality parameters were collected monthly
basis whereas heavy metals were analyzed by Atomic Adsorption Spectrometer (AAS). Heavy metals have shown within the permissible
limits, except Fe and Ni were recorded higher values in southwest monsoon, where as Mn has showed higher concentration in
northeast monsoon in and summer. All other physico-chemical parameters are with in the permissible limit. Water is moderately
hard and reservoir is productive. 相似文献