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121.
Schuller P Iroumé A Walling DE Mancilla HB Castillo A Trumper RE 《Journal of environmental quality》2006,35(5):1756-1763
Rapid and reliable methods for documenting soil erosion associated with forest harvest operations are needed to support the development of best management practices for soil and water conservation. To address this need, the potential for using 7Be measurements to estimate patterns and amounts of soil redistribution associated with individual post-harvest events was explored. The 7Be technique, which was originally developed for use on agricultural land, was employed to estimate soil redistribution associated with a period of heavy rainfall within a harvested forest area located in the Lake Region of Chile (39 degrees 44'7' S, 73 degrees 10'39' W; 22% slope; and mean annual rainfall 2300 mm yr(-1)). The results provided by the 7Be technique were validated against direct measurements of soil gain or loss during the same period obtained using erosion pins. The information produced by the two approaches was similar. The results of this study demonstrate the potential for using 7Be measurements to document event-based erosion in recently harvested forest areas. 相似文献
122.
The residual pollution after the Aznalcóllar (southwestern Spain) pyrite mine spill is still a threat due to the continuing oxidation of sulfuric minerals. The objective of this paper was to analyze the combined effect of pyrite oxidation, sugar beet foam applications, and meteorological conditions on the spatiotemporal evolution of the pH and EDTA-extractable Zn concentration, using non co-located data from 11 sampling dates between June 1999 and March 2002. Median pH values ranged from 4.4 at the beginning of the monitoring period to 7.6 at the end, although values near 2.5 were observed throughout the entire period, despite of two sugar beet foam (SBF) applications. Zinc distributions were positively skewed and median concentrations ranged from 17 to 94 mg kg(-1). The inverse relationship between pH and Zn became weaker toward the end of the monitoring period as a consequence of the precipitation and posterior dissolution of newly formed minerals from the reaction products of the pyrite oxidation. Normal score maps showed that after the SBF applications only 0.5% of the monitored area was below the pH = 4 threshold, while on other dates up to one-third of the area remained below this value. The better performance of the second SBF application could be explained in terms of pyrite oxidation pathways and environmental conditions. From this analysis, with data obtained under uncontrolled field conditions, it is concluded that SBF should be applied before or during the wet and cold season to alleviate acidification, caused by the oxidation of pyrite or other sulfuric minerals. 相似文献
123.
Chile ratified the Montreal Protocol in 1990 which sets out an agenda for the reduction and then elimination of ozone depleting substances (ODS); however, by 1998 the country had not yet defined a strategy to encourage greater compliance, so that in the same year the National Environmental Commission decided to examine the policy options available. This paper examines the process followed to develop this strategy. As a first step it was necessary to look at how far the implicit policy of "business as usual" could be stretched without jeopardizing Chile's compliance obligations. A second step included quantifying compliance costs and their impact on different policy instruments and so policy choice. Finally, the attitudes of decision-makers or participants were identified, by interviews with officials of the different public agents involved, in order to weigh their views about policy. A strategy was proposed, based on this information, which the Chilean regulator has used, although not in its entirety. The methodology developed could well be useful for developing-country Protocol signatories building their own appropriate compliance strategy. 相似文献
124.
Drozdova Irina Machs Eduard Kalimova Irina Terentyeva Larisa Bech Jaume Roca Núria Latypov Iscander 《Environmental geochemistry and health》2021,43(4):1617-1628
Environmental Geochemistry and Health - Accumulations of potentially toxic metals were investigated in soils and five North Caucasian Alyssum species from metalliferous areas and non-metalliferous... 相似文献
125.
Felton Adam Löfroth Therese Angelstam Per Gustafsson Lena Hjältén Joakim Felton Annika M. Simonsson Per Dahlberg Anders Lindbladh Matts Svensson Johan Nilsson Urban Lodin Isak Hedwall P. O. Sténs Anna Lämås Tomas Brunet Jörg Kalén Christer Kriström Bengt Gemmel Pelle Ranius Thomas 《Ambio》2020,49(5):1065-1066
Ambio - In the original published article, the sentence “Nevertheless, semi-natural forest remnants continue to be harvested and fragmented (Svensson et al. 2018; Jonsson et al. 2019), and... 相似文献
126.
García del Barrio JM Ortega M Vázquez De la Cueva A Elena-Rosselló R 《Environmental monitoring and assessment》2006,119(1-3):137-159
This paper mainly aims to study the linear element influence on the estimation of vascular plant species diversity in five Mediterranean landscapes modeled as land cover patch mosaics. These landscapes have several core habitats and a different set of linear elements -habitat edges or ecotones, roads or railways, rivers, streams and hedgerows on farm land- whose plant composition were examined. Secondly, it aims to check plant diversity estimation in Mediterranean landscapes using parametric and non-parametric procedures, with two indices: Species richness and Shannon index.Land cover types and landscape linear elements were identified from aerial photographs. Their spatial information was processed using GIS techniques. Field plots were selected using a stratified sampling design according to relieve and tree density of each habitat type. A 50×20 m2 multi-scale sampling plot was designed for the core habitats and across the main landscape linear elements. Richness and diversity of plant species were estimated by comparing the observed field data to ICE (Incidence-based Coverage Estimator) and ACE (Abundance-based Coverage Estimator) non-parametric estimators.The species density, percentage of unique species, and alpha diversity per plot were significantly higher (p < 0.05) in linear elements than in core habitats. ICE estimate of number of species was 32% higher than of ACE estimate, which did not differ significantly from the observed values. Accumulated species richness in core habitats together with linear elements, were significantly higher than those recorded only in the core habitats in all the landscapes. Conversely, Shannon diversity index did not show significant differences. 相似文献
127.
San Vicente Bay is a coastal shallow embayment in Central Chile with multiple uses, one of which is receiving wastewater from
industrial fisheries, steel mill effluents, and domestic sewage. A simulation model was developed and applied to dissolved
oxygen consumption by organic residues released into this embayment. Three compartments were established as function of: depth,
circulation and outfall location. The model compartments had different volumes, and their oxygen saturation value was used
as baseline. The parameters: (a) BOD5 of the industrial and urban effluents, (b) oxygen demand by organic sediments, (c) respiration, (d) photosynthesis and (e)
re-aeration were included in the model. Iteration results of the model showed severe alterations in Compartment 1, with a
decrease of 65% in the oxygen below saturation. Compartment 2 showed a small decline (10%) and compartment 3 did not show
apparent changes in oxygen values. Measures recommended for remediation were to decrease the BOD5 loading by 30% in the affected sector. Iteration of the model for 200 h following recommendations derived from the preceding
results produced an increase in saturation of 60% (5 ml O2 L−1), which suggested an improvement of the environmental conditions. 相似文献
128.
Reich S Magallanes J Dawidowski L Gómez D Groselj N Zupan J 《Environmental monitoring and assessment》2006,119(1-3):441-457
Air pollutant concentrations from a monitoring campaign in Buenos Aires City, Argentina, are used to investigate the relationships between ambient levels of ozone (O3), nitric oxide (NO) and nitrogen dioxide (NO2) as a function of NO
x
(=NO + NO2). This campaign undertaken by the electricity sector was aimed at elucidating the apportionment of thermal power plants to air quality deterioration. Concentrations of carbon monoxide (CO) and sulphur dioxide (SO2) were also registered. Photo stationary state (PSS) of the NO, NO2, O3 and peroxy radicals species has been analysed. The ‘oxidant’ level concept has been introduced, OX (=O3 + NO2), which varies with the level of NO
x
. It is shown that this level is made up of NO
x
-independent and NO
x
-dependent contributions. The former is a regional contribution that equates the background O3 level, whereas the latter is a local contribution that correlates with the level of primary pollution. Furthermore, the anticorrelation between NO2 and O3 levels, which is a characteristic of the atmospheric photo stationary cycle has been verified.The analysis of the concentration of the primary pollutants CO and NO strongly suggests that the vehicle traffic is the principal source of them. Levels of continuous measurements of SO2 for Buenos Aires City are reported in this work as a complement of previously published results. 相似文献
129.
A Characterization of Selected Endocrine Disruptor Compounds in a Portuguese Wastewater Treatment Plant 总被引:1,自引:0,他引:1
Maurício R Diniz M Petrovic M Amaral L Peres I Barceló D Santana F 《Environmental monitoring and assessment》2006,118(1-3):75-87
Anthropogenic compounds that are able to disrupt the endocrine system of wildlife species are a major cause for concern and
have led to a demand for new screening methods. The identification and quantification of endocrine disruptor compounds at
wastewater treatment plant is of major interest to assess the endocrine activity of wastewater treatment plant discharges
into the environment. This study consists of a preliminary survey of concentrations of previously selected endocrine disruptor
compounds, undertaken to establish environmental concentrations and to support a biological program assay exposing freshwater
fish to them. Selected endocrine disrupting chemicals (APEs, bisphenol A and 17 β-estradiol) were measured in samples from a wastewater treatment plant located in Lisbon (Portugal), using recent commercial
enzyme-linked immunosorbent assay kits and also LC-MS/MS. The results show that the wastewater treatment plant treatment process
is efficient on the removal of target endocrine disruptor compounds. However, environmentally significant concentrations are
still present in the treated effluent. The results also show that enzyme-linked immunosorbent assay kit is suitable for routine
analysis of the selected compounds. The results are also useful since the wastewater treatment plant is located in a Mediterranean
region, which results in an effluent with its own characteristics. 相似文献
130.
Thomassen Y Koch W Dunkhorst W Ellingsen DG Skaugset NP Jordbekken L Arne Drabløs P Weinbruch S 《Journal of environmental monitoring : JEM》2006,8(1):127-133
The number concentration and size distribution of ultrafine particles in a S?derberg and a prebake potroom of an aluminium primary smelter have been measured using a scanning mobility particle spectrometer. The particle morphology was studied by transmission electron microscopy (TEM). The study shows the existence of elevated number concentrations of ultrafine particles in both potrooms. The main source of these particles is likely to be the process of anode changing. The ultrafine particles were measured directly at the source but could also be identified as episodes of high number concentrations in the general background air. Unlike the larger particles belonging to the 50-100 nm mode, the nanoparticle mode could not be detected in the TEM indicating that they may not be stable under the applied sampling conditions and/or the high vacuum in the instrument. 相似文献