Modelling the recovery of acid-sensitive Finnish headwater lakes under present emission reduction agreements

International audienceAbstract: Over the past two decades, substantial reductions in the deposition of acidifying substances (primarily sulphur) have occurred in most parts of Europe and, following recent agreements, this trend is likely to continue. The question arises as to how have sensitive ecosystems reacted, and will react in the future, to these reduced inputs of acidity? In this paper, the SMART dynamic acidification model predicts the possible recovery of 36 acid-sensitive Finnish headwater lakes, for which both catchment soil and water quality measurements were available. The model was calibrated to measurements by adjusting poorly known parameters; it was then used to simulate soil and water chemistry until 2030 under the ?current legislation scenario' resulting from implementing current European emission reduction agreements. Whereas most of the catchment soils show very little change in base saturation, the positive trends in lake ANC and the negative trends in lake sulphate concentrations, observed over the past decade, continue into the future, albeit at a slower pace. The model predicts that, during 2010?30, all lakes will have reached a positive ANC, a pre-requisite for the recovery of fish populations. Keywords: acidification, lake, catchment, recovery, SMART model, Finland</p

Acidification in Europe : A Simulation Model for Evaluating Control Strategies

RAINS (Regional Acidification Information and Simulation) is an integrated model of acidification in Europe designed as a tool for evaluating control strategies. It is currently sulfur-based, but is being expanded to include nitrogen species. Emphasis of the model is on the transboundary aspects of the acidification problem. Model computations are performed on a personal computer. Linked submodels are available for SO2 emissions, cost of control strategies, atmospheric transport of sulfur, forest soil and groundwater acidity, lake acidification, and the direct impact of SO2 on forests. The model can be used for scenario analysis, where the user prescribes a control strategy and then examines the cost and environmental consequences of this strategy, or for optimization analysis, in which the user sets cost and deposition goals, and identifies an "optimal" sulfur-reduction strategy. Preliminary use of the model has pointed to 1. the importance of examining long-term environmental consequences of control strategies, and 2. the cost advantages of a cooperative European sulfur-reduction program

Pioneeriaselajissa sodan jälkeen tapahtuneen kehityksen suuntaviivat

Artikkeli on useiden kyvykkäiden pioneeriupseerien laatimien selostusten yhdistelmä. Pioneeritoiminta on jaettu linnoittamiseen, sulutustoimintaa, ylimenotoimintaan, tietöihin, selustan rakennustoimintaan sekä pioneerihuoltoon. Johdannossa todetaan, että kehittämisessä tuloksia tuottavaksi menettelytavaksi ovat osoittautuneet tehtävä- tai tutkimusalakohtaisesti muodostetut toimikunnat. Toisessa luvussa tarkastellaan pioneerijoukkojen tehtäviä ja organisaatioita. Pioneerijoukot jaetaan siinä käsitteellisesti taistelupioneereihin ja rakentajapioneereihin sekä käsitellään niiden tehtäviä. Organisaatiota käsiteltäessä todetaan, että pioneerijoukkojen käytölle on luonteenomaista keskittäminen. Perusyhtymä on alin johtoporras, jolla on orgaanisia pioneereja. Lisäksi käsitellään lyhyesti pioneeritoiminnan johtamista. Kolmannessa luvussa tarkastellaan linnoittamista, ottaen esille yleisperiaatteiden lisäksi ulkomaisen ja suomalaisen linnoittamisen kehittämisen. Siinä todetaan muun muassa että, linnoittamisalan ohjesäännöt on uusittu ja eritystä huomiota on kiinnitetty rakenteiden yksinkertaistamiseen, työmäärän vähentämiseen ja nopeuttamiseen sekä materiaalitarpeen pienentämiseen lujuutta vähentämättä. Sulutustoimintaa ( hävittäminen, miinoittaminen ja miinoitteiden raivaaminen) ja käsittelevässä luvussa käsitellään ensin perusteena sodista saatuja oppeja ja sen jälkeen niiden perusteella tehtyjä taktillisia johtopäätöksä. Lopuksi todetaan, että suluttamisella on tulevaisuuden sodissa yhä kasvava merkitys. Ylimenotoimintaa käsittelevässä luvussa esitellään ensi ulkomaisia kalustoja ja sitten tarkastellaan kotimaisten kalustojen kehittämispiirteitä. Loppuluvuissa tarkastelun kohteena ovat tietyöt ja pioneerihuolto. Loppulauseessa todetaan, että pioneerit eivät käy omaa sotaansa , vaan "Pioneeritoiminnan tuloksellisuus perustuu ennen kaikkea kitkattomaan yhteistoimintaa.

Integrated Analysis of Acidification in Europe.

This paper presents the interim status of the RAINS model developed at IIASA. The principle purpose of the model is to provide a tool to assist decision-makers in their evaluation of strategies to control acidification of Europe's environment. Model design emphasizes user comprehension and ease of use. The overall framework of RAINS consists of three linked compartments: "Pollutant Generation," "Atmospheric Processes" and "Environmental Impact." Each of these compartments can be filled by different substitutable submodels. The four submodels currently available are "Sulfur Emissions," EMEP Sulfur Transport," Forest Soil Acidity" and "Lake Acidity." Submodels which deal with NOx emissions and deposition and other environmental impacts will be added to the model. To operate the model, a user must select (1) an energy pathway, (2) a pollution control strategy and (3) an environmental impact indicator. This information is inputed to RAINS and yields a "scenario" which is a consistent set of energy pathway, sulfur emissions, forest soil acidity and lake acidity. In an iterative fashion, a model user can quickly evaluate the consequences of many different alternatives to control acidification in Europe

Acidification of forest soils : Model development and application for analyzing impacts of acidic deposition in Europe.

Acidification is considered to be an unfavourable process in forest soil. Timber logging, natural accumulation of biomass in the ecosystem, and acidic deposition are known sources of acidification. Acidification causes a risk of damage to plant roots and subsequent risk of a decline in ecosystem productivity. A dynamic model is introduced for describing the acidification of forest soils. In 1-year time steps the model calculates the soil pH as a function of the acid stress and the buffer mechanisms of the soil. Acid stress is defined as the hydrogen ion input into the top soil. The buffer mechanisms counteract acidification by providing a sink for hydrogen ions. The concepts buffer rate and buffer capacity are used to quantify the buffer mechanisms. The model compares (a) the rate of acid stress (annual amount) with the buffer rate, and (b) the accumulated acid stress (over several years) with the buffer capacity. These two comparisons give an estimate of the soil acidity. The model was incorporated into the Regional Acidification Information and Simulation (RAINS) model system of the International Institute for Applied Systems Analysis for analyzing the acidic deposition problem in Europe. This system links information on energy production, pollutant emission, pollutant transport, and pollutant deposition. The data on acid stress entering the soils was obtained from other submodels. Data on buffer rate and buffer capacity were collected from soil maps and geological maps. The model system as a whole is now available for analyzing the impact of different emission scenarios. The soil acidification model assumes sulfur deposition estimates from the other submodels as input, and as output it produces estimates of the acidity of European forest soils in a map format. Additionally it computes the total area of forests in Europe with the estimated soil pH lower than any selected threshold value. Sources of uncertainty in the soil acidification model are listed and briefly evaluated

Water quality monitoring in the former Soviet Union and the Russian Federation : Assessment of analytical methods

Monitoring of surface water quality in the former Soviet Union (FSU) and the present-day Russian Federation historically held an important place in the hierarchy of science, legal framework and relations between agencies. Sadly, the gap between the intentions, qualification of managers and effective programmes has always been sizeable. Since disintegration of the FSU this gap has become a formidable barrier for collecting reliable monitoring information and producing effective water quality management decisions in the Russian Federation. Updating the federal system for freshwater quality monitoring in the Russian Federation is complicated by several unresolved problems. The principal issues are political, technical, institutional and financial. The existing Russian model of water chemistry data collection inherited from the FSU has proved unreliable, outdated and unrelated to modern national issues of water management. The quality of produced data is one of the greatest weaknesses of the federal monitoring system both in the Russian Federation and in other states of the FSU. A significant cause of the low reliability of the produced information is the analytical methods used in monitoring, their inappropriate use, non-compliance to laboratory practices when following expert recommendations, insufficient training level of managers and laboratory personnel and under-funding of the federal monitoring system. The growing national priorities in the field of surface water quality control and improvement conflict with the capacity of the Russian Federation to provide necessary information of guaranteed high quality. Here we make the first attempt to present a critical analysis of the analytical methods used to assess and control surface water quality, to show the main errors arising when applying the recommended analytical methods, and to assess the degree of reliability of produced monitoring information from 1977-1978 and to the present. Our overall objective is to summarize the current situation in order to facilitate implementation of future improvements

Modelling the response of soil and runoff chemistry to forest harvesting in a low deposition area (Kangasvaara, eastern Finland)

A simple dynamic soil model developed to analyse the effects of atmospheric deposition and nutrient cycling on terrestrial ecosystems, SMART 2, was applied to the Kangasvaara catchment in eastern Finland. Given the historical deposition and forest growth patterns and reasonable values for the input parameters, SMART 2 was calibrated successfully to reproduce present-day soil and Kangasvaara catchment on the soil and runoff water chemistry under a future deposition scenario (GRP scenario). These impacts were also compared to the effects of further reducing the deposition of sulphur and nitrate under the maximum feasible reduction (MFR) scenario. The model demonstrates the consequences of breaking the nutrient cycle, and predicts that final cutting results in increased leaching of inorganic nitrogen and base cations from the cut part of the catchment for about 10 years. The resulting concentrations in the stream will depend on the ability of the buffer zones surrounding the stream to capture and utilize these nutrients

Simulation of the long-term soil response to acid deposition in various buffer ranges

A soil acidification model has been developed to estimate long-term chemical changes in soil and soil water in response to changes in atmospheric deposition. Its major outputs include base saturation, pH and the molar Al/BC ratio, where BC stands for divalent base cations. Apart from net uptake and net immobilization of N, the processes accounted for are restricted to geochemical interactions, including weathering of carbonates, silicates and Al oxides and hydroxides, cation exchange and CO2 equilibriums. First, the model's behavior in the different buffer ranges between pH 7 and pH 3 is evaluated by analyzing the response of an initially calcareous soil of 50 cm depth to a constant high acid load (5000 molc ha-1 yr-1) over a period of 500 yr. In calcareous soils weathering is fast and the pH remains high (near 7) until the carbonates are exhausted. Results indicate a time lag of about 100 yr for each percent CaCO3 before the pH starts to drop. In non-calcareous soils the response in the range between pH 7 and 4 mainly depends on the initial amount of exchangeable base cations. A decrease in base saturation by H/BC exchange and Al/BC exchange following dissolution of Al3+ leads to a strong increase in the Al/BC ratio near pH 4. A further decrease in pH to values near 3.0 does occur when the A1 oxides and/or hydroxides are exhausted. The analyses show that this could occur in acid soils within several decades. The buffer mechanisms in the various pH ranges are discussed in relation to Ulrich's concept of buffer ranges. Secondly, the impact of various deposition scenarios on non-calcareous soils is analyzed for a time period of 100 yr. The results indicate that the time lag between reductions in deposition and a decrease in the Al/BC ratio is short. However, substantial reductions up to a final deposition level of 1000 molc ha-1 yr-1 are needed to get Al/BC ratios below a critical value of 1.