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1.
Jeffries D. S. Semkin R. G. Beall F. D. Franklyn J. 《Water, Air, & Soil Pollution: Focus》2002,2(1):5-22
The Turkey Lakes Watershed (TLW) was established in 1980 as asite for study of the ecosystem effects of acidic deposition, andsince then there has been 40% reduction in North AmericanSO2 emissions. Monitoring records for bulk deposition,shallow and deep ground water, two headwater streams and two lakeoutflows have been tested to identify statistically significantmonotonic trends. The TLW appears to be responding to decliningacidifying emissions because the most prevalent chemical trendacross sample types/stations was decreasing SO4
2-. Increasing pH was detected in four of the seven data sets, butonly the H+ decrease in bulk deposition was of a magnitudeto be an important ionic compensation for the SO4
2-decline. There is little evidence of acidification recovery inTLW waters however. Increasing alkalinity was found only in theoutflow of the penultimate lake of the basin, and in fact, deepground water and the other lake outflow had decreasing alkalinitytrends (i.e., continuing acidification). For the surface waterstations, the greater part of the ionic compensation fordeclining SO4
2- was decreasing base cations, and as aresult, these waters are probably becoming more dilute with time,although only the headwater streams exhibited decliningconductivity. Five of seven data sets had increasing dissolvedorganic carbon concentrations. Increasing NO3
- wasimportant in ground waters. Drought has strongly influencedtrends and delayed recovery by mobilizing S stored in catchmentwetlands and/or soils. 相似文献
2.
Michel Robert L. Turk John T. Campbell Donald H. Mast M. A. 《Water, Air, & Soil Pollution: Focus》2002,2(2):5-18
Measurements of the cosmogenically-produced 35S, a radioisotope of sulphur (t1/2 = 87 days), are reported for the Ned Wilson Lake watershed in Colorado. The watershed contains two small lakes and a flowing spring presumed to be representative of local ground water. The watershed is located in the Flattops Wilderness Area and the waters in the system have low alkalinity, making them sensitive to increases in acid and sulphate deposition. Time series of 35S measurements were made during the summers of 1995 and 1996 (July–September) at all three sites. The system is dominated by melting snow and an initial concentration of 16–20 mBq L-1 was estimated for snowmelt based on a series of snow samples collected in the Rocky Mountains. The two lakes had large initial 35S concentrations in July, indicating that a large fraction of the lake water and sulphate was introduced by meltwater from that year's snowpack. In 1995 and 1996, 35S concentrations decreased more rapidly than could be accounted for by decay, indicating that other processes were affecting 35S concentrations. The most likely explanation is that exchange with sediments or the biota was removing 35S from the lake and replacing it with older sulphate devoid of 35S. In September of 1995 and 1996, 35S concentrations increased, suggesting that atmospheric deposition is important in the sulphate flux of these lakes in late summer. Sulphur-35 concentrations in the spring water were highly variable but never higher than 3.6 mBq L-1 and averaged 2 mBq L-1. Using a simple mixing model, it was estimated that 75% of the spring water was derived from precipitation of previous years. 相似文献
3.
Long-term monitoring of a predominantlyconiferous catchment (PC-1) in central Ontario has enabledmass budgets of base cations to be estimated between 1983and 1998. During this period, sulphur deposition decreasedby approximately 30%, although this region still receivesacid deposition that exceeds the critical load with respectto acidity for forest soils. Between 1983 and 1998 therewas a net loss of 76.3 kg ha-1 Ca and 13.7 kg ha-1Mg from PC-1, and a net retention of K of 55.7 kg ha-1. A net loss of Ca and Mg occurred every year during the studyperiod (except 1986/87 for Mg), although annual losses of Caand Mg have been generally lower in recent years. On anannual basis, net losses of Ca and Mg were extremelyvariable and were strongly related to export of SO4,which in turn appeared to be strongly influenced by climatefactors. Measured losses of Ca and Mg over the 16-yearperiod represented 37% and 59% of their respectiveexchangeable pools measured in the upland soils in 1983.These values probably overestimate base cation losses fromthe upland however, because losses from organic soils in thecatchment were proportionately greater during yearsfollowing El Niño events. There was no change in basal areabetween 1983 and 1998, although there was a shift towardless nutrient-demanding species (white pine, hemlock). Pools of Ca and Mg in tree biomass are approximately doubletheir exchangeable pools in podzols, and so losses from soilmay be offset by changes in forest structure (size,composition) in the short-term (decades). If net losses ofCa and Mg continue due to harvesting and/or acid depositionand estimates of weathering and exchangeable pools arecorrect, then the long-term sustainability of the uplandforest at PC-1 must be in doubt. 相似文献
4.
Trends have been analysed for 12 years ofchemical data from six mountain lakes in the UK AcidWaters Monitoring Network (AWMN). With minimal localanthropogenic impacts, these sites offer the bestavailable opportunity for clear identification of surfacewater chemical response to external factors, whethernatural or anthropogenic. Results indicate that naturalclimatic variations have had a major impact on lakechemistry, through fluctuations in (i) intensity ofstorms, which cause dilution of weathering-derived basecations, and/or displacement of hydrogen and aluminiumions on soil exchange sites by deposited marine basecations; and (ii) winter temperature, which is thought tobe inversely related to spring nitrate (NO3) maxima.Both climatic factors can be linked to the North AtlanticOscillation. For the first decade of AWMN monitoringthese natural `confounding factors' to a significantextent obscured any recovery from acidification due todeclining anthropogenic sulphur deposition. However, theadditional data presented here provide strengtheningevidence for chemical recovery at a number of sites, atwhich decreases in sulphate (SO4), acidity andlabile aluminium can now be identified. It is believedthat changes at these sensitive mountain lake sites mayherald more widespread recovery in UK surface waters aspollutant emissions decline further. However, largeincreases in dissolved organic carbon, and hence inorganic acidity, may have partially offset reductions inmineral acidity. The cause of these increases remainsuncertain, but may be linked to climatic change. 相似文献
5.
Relation of Lake Acidification and Recovery to Fish,Common Loon and Common Merganser Occurrence in Algoma Lakes 总被引:3,自引:0,他引:3
Models are needed that predict both spatial and temporal improvements to ecosystems following reductions of acidifying emissions that produce `acid rain'. Logistic regression models were developed for the occurrence of fish and two fish-eatingbirds, common loons (Gavia immer) and common mergansers(Mergus merganser), using monitoring data collected onlakes across Ontario. These models were applied in the Algomaregion, including the Turkey Lakes Watershed (TLW). Using theWaterfowl Acidification Response Modeling System (WARMS), severalSO2 emission reduction scenarios were simulated, i.e. thosecontributing to measured 1982–1986 sulphate deposition levels, 1994levels (corresponding to full implementation of Canadian SO2emission reductions as stipulated in the 1991 Canada/U.S. AirQuality Agreement), 2010 levels (1994 plus full U.S. reductions),and both a 50% and a 75% further reduction beyond 2010 levels. Some habitat improvements in Algoma were predicted under the 2010scenario for all biota, but substantial increases in habitatquality, especially for mergansers, would occur only under further reductions. The TLW showed little change in chemistry orbiota, while lakes near the Montreal River were predicted toimprove substantially. 相似文献
6.
Trends in the Water Chemistry of High Altitude Lakes in Europe 总被引:2,自引:0,他引:2
Mosello R. Lami A. Marchetto A. Rogora M. Wathne B. Lien L. Catalan J. Camarero L. Ventura M. Psenner R. Koinig K. Thies H. Sommaruga-Wögrath S. Nickus U. Tait D. Thaler B. Barbieri A. Harriman R. 《Water, Air, & Soil Pollution: Focus》2002,2(2):75-89
Here we present the chemical trends of seven high altitude lakes, analysed within the AL:PE and MOLAR Projects of the EU (1999) and selected on the basis of the availability of complete and reliable data for the period 1984–1999. The lakes are representative of the Scandinavian Alps, the Cairngorm Mountains in Scotland, the Alps and the Pyrenees. Significant trends were identified for some indicators of acidification, for instance pH and alkalinity, but not all lakes reacted similarly to decreasing depositions of sulphate and base cations. Differences in lake response are discussed in relation to recent variations of atmospheric deposition chemistry and associated changes in climatic conditions. Beside individual variations of the studied lakes, depending, among other things, on altitude and morphology, catchment characteristics and climate trends play a major role for the reaction of high altitude lakes on changes in atmospheric depositions. 相似文献
7.
Long-term (i.e. >10 years) whole community fish dataincluding catch-per-unit-effort, abundance, biomass, andproduction from three lakes were used: 1) to examine variabilityin fish population and community measures among years using wholelake assessments of fish populations derived from mark recaptureexperiments, 2) to assess implications arising from monitoringindividual species vs. the whole fish community, and 3) toascertain whether, in fisheries assessments (science) a commonlyused surrogate measure, [catch-per-unit-effort (CPUE)] reflectedannual changes in the fish assemblage, and thus may be a goodestimator of abundance. High, long-term variability was evident in the abundance andbiomass of a fish species in our lakes, yet the communityremained relatively stable in terms of its biomass andproduction. Changes in total fish community biomass appear drivenby large species, which, relative to small fish species, remainstable among years. Among years, species richness remainedstable; however, fish species changed in the community. AnnualCPUE was found to be a suitable surrogate for abundance (N) ofsmall fishes; CPUE x mean weight of the catch (bCPUE) was asuitable surrogate for biomass (B) of large fishes. Prior toconcluding that a change in a fish population has occurred as aresult of a stressor, care must be taken to critically examinethe level of population assessment in order to avoid acceptingpotentially invalid conclusions. 相似文献
8.
Reduced emissions of acidifying pollutants have changed the acidification process, and as a result, forest soils and surface
waters are slowly recovering in Sweden. However, model calculations show that some areas may never recover completely unless
further measures, such as liming, are undertaken. Liming of surface waters (lakes, rivers and wetlands) has been successfully
practised in Sweden since the 1970s, but repeated treatments are necessary. A full recovery of acidified lakes and streams
without frequent liming is however not possible until soil acidification is reversed in the most strongly affected areas.
In this study, the recovery of acidified streams was examined using ‘the total catchment approach’ i.e. treatment of both
recharge and discharge areas. The aim was to compare the quantitative effect of different treatments on run off chemistry
and the recovery of brown trout. Catchments in southwest Sweden were treated with a combination of 2 tons of wood ash and
4, 6 or 12 tons of crushed limestone per hectare in 1998/1999. Treatment of both recharge and discharge areas resulted in
fast and significant changes in stream water quality, e.g. increased concentrations of calcium, higher pH and ANC and a decreased
concentration of inorganic aluminium. The initial changes were dependent on the distribution of the applied lime between discharge
and recharge areas rather than the average dose on the total catchment. Treatment of recharge areas only, resulted in smaller
but still significant effects on calcium, pH and ANC in stream water. Furthermore, there was an initial leaching of nitrate
but it was only minor compared with the elevated leaching that occurs after a clear-cut. As a result of the treatments, brown
trout is now successfully reproducing.
Olle Westling (deceased). 相似文献
9.
Curtis C. J. Barbieri A. Camarero L. Gabathuler M. Galas J. Hanselmann K. Kopaček J. Mosello R. Nickus U. Rose N. Stuchlik E. Thies H. Ventura M. Wright R. 《Water, Air, & Soil Pollution: Focus》2002,2(2):115-126
Critical load models for acidityprovide a measure of the sensitivity of surfacewaters to acid deposition, and can be used todetermine critical load exceedance and potentiallong-term harmful effects. Three static models,the Steady-State Water Chemistry model, diatommodel and First-order Acidity Balance model, arehere applied to 11 high mountain lakes in Norway,Scotland, the Alps, the Pyrenees and the Tatras.Between five and seven of the lakes show criticalload exceedance, depending on the model used.Nitrogen as well as sulphur deposition isimportant in causing exceedance. Since soil andvegetation cover are generally sparse, geologyand lake retention time appear to be key factorsin the determination of critical load. Retentionof nitrogen is observed, but it is unclearwhether this occurs within the lake or theterrestrial part of the catchment. 相似文献
10.
11.
David Moncoulon Anne Probst Liisa Martinson 《Water, Air, & Soil Pollution: Focus》2007,7(1-3):307-316
To evaluate the acid deposition reduction negotiated for 2010 within the UNECE LRTAP Gothenburg Protocol, sulphur and nitrogen
deposition time-series (1880–2100) were compared to critical loads of acidity on five French ecosystems: Massif Central basalt
(site 1) and granite (2); Paris Bassin tertiary sands (3); Vosges mountains sandstone (4) and Landes eolian sands (5). The
SAFE model was used to estimate the response of soil solution pH and ratio to the deposition scenario. Among the five sites, critical loads were exceeded in the past at sites 3, 4 and 5. Sites
3 and 4 were still expected to exceed in 2010, the Protocol year. Further reduction of atmospheric deposition, mainly nitrogen,
would be needed to achieve recovery on these ecosystems. At sites 3, 4 and 5, the delay between the critical load exceedance
and the violation of the critical chemical criterion was estimated to be 10 to 30 years in the top soil and 50 to 90 years
in the deeper soil. At site 5, a recovery was expected in the top soil in 2010 with a time lag of 10 years. Unexpectedly,
soil pH continued to decrease after 1980 in the deeper soil at sites 2 and 5. This time lag indicated that acidification moved
down the soil profile as a consequence of slow base cation depletion by ion exchange. This delayed response of the soil solution
was the result of the combination of weathering rates and vegetation uptake but also of the relative ratio between base cation
deposition and acid compounds. 相似文献
12.
Strongly decreasing atmospheric emissions and acidic deposition during the 1990s have initiated chemical reversal from acidification
in several drinking-water reservoirs of the Erzgebirge, SE Germany. We studied responses of phytoplankton, zooplankton and
fish stocks in five reservoirs and at enclosure scale after experimental neutralization of 1,200 m3 of lake water. About 4 months after this treatment, diatoms and cryptomonads replaced the predominating chrysophytes and
dinoflagellates. The colonization by acid-sensitive species of green algae, cryptomonads, rotifers and Cladocera (e.g. Bosmina longirostris) is explained by the occurrence of dormant stages or by survival of individuals in very low abundances. Analogous to the
enclosure experiment, three reservoirs showed significantly (p < 0.01) falling trends of chlorophyll a and phytoplankton biovolume, mainly due to the decline of dinoflagellates. Picoplankton and diatoms increased slightly in
two reservoirs. The zooplankton communities were dominated by rotifers and small Cladocera. Representatives of the genus Daphnia were lacking. Two reservoirs were re-colonized by zooplanktivorous fish populations of either perch (Perca fluviatilis) or sunbleak (Leucaspius delineatus). The latter exhibited extremely high fluctuating abundance and biomass and even suffered from a population crash. This natural
mortality was caused by a limited food supply. Hence, severe top-down control may delay the recovery of larger zooplankton
species like daphnids. Fishery management comprising the introduction of predatory fishes can help to control zooplanktivorous
fish populations and to prevent their mass mortality. 相似文献
13.
Hysteresis in Reversal of Central European Mountain Lakes from Atmospheric Acidification 总被引:2,自引:0,他引:2
Kopáček Jiří StuchlÍk Evžen Veselý Josef Schaumburg Jochen Anderson Iris C. Fott Jan Hejzlar Josef Vrba Jaroslav 《Water, Air, & Soil Pollution: Focus》2002,2(2):91-114
Extremely high emissions of S and N compounds in Central Europe (both 280 mmol m-2 yr-1) declined by 70and 35%, respectively, during the last decade. Decreaseddeposition rates of SO4
-2, NO3
-, and NH4
+ in the region paralleled emission declines. The reduction in atmospheric inputs of S and N to mountain ecosystemshas resulted in a pronounced reversal of acidification in the Tatra Mountains and Bohemian Forest lakes. Between the 1987–1990and 1997–1999 periods, concentrations of SO4
-2 and NO3
- decreased (average ± standard deviation) by 22±7 and 12±7 mol L-1, respectively, in theTatra Mountains, and by 19±7 and 15±10 mol L-1, respectively, in the Bohemian Forest. Their decrease was compensated in part (1) by a decrease in Ca2+ + Mg2+ (17±7 mol L-1) and H+ (4±6 mol L-1), and an increase in HCO3
-(10±10 mol L-1) in the Tatra Mountains lakes, and (2) by a decrease in Al (7±4 mol L-1), Ca2+ + Mg2+ (9±6 mol L-1), and H+ (6±5 mol L-1), in Bohemian Forest lakes. Despite the rapid decline in lake water concentrations of SO4
-2 and NO3
- in response to reduced S and N emissions, their present concentrations in some lakes are higher than predictionsbased on observed concentrations at comparable emission rates during development of acidification. This hysteresis in chemical reversal from acidification has delayed biological recovery of the lakes. The only unequivocal sign of biological recovery hasbeen observed in erné Lake (Bohemian Forest) where a cladoceran species Ceriodaphnia quadrangular has recentlyreached its pre-acidification abundance. 相似文献
14.
Reduction of sulphur deposition causesrecovery of acidified surface waters. Processes in thecatchment delay recovery. The acidification model MAGICwas applied to the Vikedal and Tovdal rivers in southernNorway. Response in water chemsitry is delayed by 10–20 yr. The delay is due to release of old sulphate atVikedal and cation exchange at Tovdal. Assuming that theGothenburg protocol is fully implemented by the year2010, much of the predicted increase of ANC will occur inthe next 10 yr with a levelling off by about 2040. Ifnitrogen leaching increases in the future, however,recovery of ANC will not be as rapid, nor as complete.Critical load for acidity calculated by steady-statemodels is confirmed by the MAGIC predictions. Futurerequirement for mitigation measures such as liming willdecrease in the future as acid deposition decreases. Bythe year 2046 the liming requirement will be reduced byabout 45% at Vikedal and 65% at Tovdal. One of the mainpurposes of the Norwegian national monitoring programmeis to provide documentation of changes in environmentalquality due to long-range transported air pollutants.Modelling applications such as this clearly show that thedata fill this purpose. 相似文献
15.
The critical loads concept is used by the UN-ECEConvention on Long Range Transboundary Air Pollution(CLRTAP) for setting pollution reduction targets.Increasing numbers of countries are adopting the SimpleMass Balance equation (SMB) to calculate critical loads ofacidifying S and N for forest soils. The equation is madeup of a series of mass balances each of which is used tocalculate a leaching flux. The assumptions in the SMBequation were investigated by testing its ability topredict current sulphur load and by comparing each of thecalculated leaching fluxes to measured rates. It was notpossible to predict current sulphur load at our sites usingthe SMB equation. The leaching tests demonstrated that,primarily due to its steady state assumptions, the SMBequation generates critical loads that are theoretical longterm estimates of risk, and are untestable. Thesimplifying assumptions sometimes lead to illogicalresults. Some of these can be improved by adding a final,simple but dynamic, calculation step to determine theexpected time until effects are observed. Theacceptability of combining annual average data, which bestapproximates steady state, with a biological indicator isquestionable. It is not possible to test critical loadscalculated using the SMB equation when applied with all ofits assumptions but it is possible to test its fundamentalapproach using non steady state data. 相似文献
16.
J. Aherne T. Larssen P. J. Dillon B. J. Cosby 《Water, Air, & Soil Pollution: Focus》2004,4(2-3):37-48
One of the principal influences on elemental fluxes from forestedcatchments in south-central Ontario is the atmospheric deposition rate of strong acids. While sulphate deposition has decreased by ~40% in the past two decades, nitrate deposition has remained unchanged and is now equivalent to sulphate deposition. Sulphate concentrations in headwater lakes and their inflows have decreased, but much less than expected based on the anticipated direct response of the catchments. Reduction-oxidation (redox) processes occurring in wetlands have been identified as the reasonfor delayed recovery, and climate events as controlling these redoxprocesses. A new version of the biogeochemical model MAGIC (modelof acidification of groundwater in catchments) with a wetland compartment that incorporates redox processes driven by climate events has been generated. The application of MAGIC to a subcatchmentof Plastic Lake in south-central Ontario indicates that the basic structure of the model appears to be consistent with the observeddata. Moreover, the wetland component was essential in reproducingthe observed trends, which include sulphate retention in non-droughtyears and re-oxidation of previously stored (reduced) sulphur in drought years. 相似文献
17.
D. Williams B. A. Emmett S. A. Brittain B. Reynolds P. A. Stevens D. Benham 《Water, Air, & Soil Pollution: Focus》2004,4(6):187-196
A field-based system used to quantify the response of acid grassland to reduced atmospheric nitrogen and sulphur deposition, and to investigate the effects of elevated soil temperature on acid grassland development is described. The system is based on 12 retractable roofs, covering undisturbed experimental plots of acid grassland and three controls. Nine roofs are used to exclude natural precipitation and three roofs used to retain emitted IR radiation at night. An irrigation system has been developed to simulate natural precipitation, allowing for the application of specific treatment regimes of ambient, reduced nitrogen and reduced nitrogen/sulphur deposition beneath the nine rain exclusion plots. Plant, soil parameters, leachate chemistry and gaseous fluxes are being monitored and initial results on soil water chemistry are described. Warming appeared to enhance nitrate concentrations in soil water but this was not sustained beyond the first year of treatment. In contrast, the deposition reduction treatments decreased soil water nitrate concentrations within a few weeks of reducing deposition. This was not observed for other solutes such as sulphate or ammonium suggesting a more direct link between deposition of nitrate and leaching losses. 相似文献
18.
Mizpah Asase Ernest K. Yanful Moses Mensah Jay Stanford Samuel Amponsah 《Waste management (New York, N.Y.)》2009,29(10):2779-2786
Integrated waste management has been accepted as a sustainable approach to solid waste management in any region. It can be applied in both developed and developing countries. The difference is the approach taken to develop the integrated waste management system. This review looks at the integrated waste management system operating in the city of London, Ontario-Canada and how lessons can be drawn from the system’s development and operation that will help implement a sustainable waste management system in the city of Kumasi, Ghana. The waste management system in London is designed such that all waste generated in the city is handled and disposed of appropriately. The responsibility of each sector handling waste is clearly defined and monitored. All major services are provided and delivered by a combination of public and private sector forces.The sustainability of the waste management in the city of London is attributed to the continuous improvement strategy framework adopted by the city based on the principles of integrated waste management. It is perceived that adopting a strategic framework based on the principles of integrated waste management with a strong political and social will, can transform the current waste management in Kumasi and other cities in developing countries in the bid for finding lasting solutions to the problems that have plagued the waste management system in these cities. 相似文献
19.
Bauxite residue (red mud) is a hazardous waste generated from alumina refining industries. Unless managed properly, red mud poses significant risks to the local environment due to its extreme alkalinity and its potential impacts on surface and ground water quality. The ever-increasing generation of red mud poses significant challenges to the aluminium industries from management perspectives given the low proportion that are currently being utilized beneficially. Red mud, in most cases, contains elevated concentrations of iron in addition to aluminium, titanium, sodium and valuable rare earth elements. Given the scarcity of iron supply globally, the iron content of red mud has attracted increasing research interest. This paper presents a critical overview of the current techniques employed for iron recovery from red mud. Information on the recovery of other valuable metals is also reviewed to provide an insight into the full potential usage of red mud as an economic resource rather than a waste. Traditional hydrometallurgy and pyrometallurgy are being investigated continuously. However, in this review several new techniques are introduced that consider the process of iron recovery from red mud. An integrated process which can achieve multiple additional values from red mud is much preferred over the single process methods. The information provided here should help to improve the future management and utilization of red mud. 相似文献
20.
Major sulphur emission control programs have been implemented in North America, resulting in current emissions being ~30% less than those in 1980. However, the level of acidic deposition remaining is still unlikely to promote widespread recovery of aquatic ecosystems. The First-order Acidity Balance (FAB) model has been applied to south-central Ontario (285 lakes in the Muskoka River Catchment) to evaluate the need for further reductions in emissions. As a result of the past decline in deposition, the proportion of lakes with critical loads exceedance has dropped substantially; however, further reductions in sulphur and nitrogen emissions are required to eliminate critical loads exceedance. Based on bulk deposition of sulphate and nitrogen (41.1 mmolc m-2 yr-1 and 62.5 mmolc m-2 yr-1, respectively) for the period 1995–1999, 166 lakes (58.3%) exceedcritical loads. Even with full implementation of SO2 abatementprograms in Canada (achieved in 1994) and the United States (legislated for 2010), critical loads will be exceeded in a large proportion (46.6%) of the study lakes. 相似文献