Browsing by Subject "sulfaatit"

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  • Alasaarela, Erkki (Vesihallitus. National Board of Waters, 1982)
    Vesientutkimuslaitoksen julkaisuja 49, 3-16
    Kyrönjoen tulvasuojelutöiden aiheuttamista happamuusongelmista
  • Mattsson, Tuija (Finnish Environment Institute, 2010)
    Monographs of the Boreal Environment Research 36
    The terrestrial export of dissolved organic matter (DOM) is associated with climate, vegetation and land use, and thus is under the influence of climatic variability and human interference with terrestrial ecosystems, their soils and hydrological cycles. The present study provides an assessment of spatial variation of DOM concentrations and export, and interactions between DOM, catchment characteristics, land use and climatic factors in boreal catchments. The influence of catchment characteristics, land use and climatic drivers on the concentrations and export of total organic carbon (TOC), total organic nitrogen (TON) and dissolved organic phosphorus (DOP) was estimated using stream water quality, forest inventory and climatic data from 42 Finnish pristine forested headwater catchments, and water quality monitoring, GIS land use, forest inventory and climatic data from the 36 main Finnish rivers (and their sub-catchments) flowing to the Baltic Sea. Moreover, the export of DOM in relation to land use along a European climatic gradient was studied using river water quality and land use data from four European areas. Additionally, the role of organic and minerogenic acidity in controlling pH levels in Finnish rivers and pristine streams was studied by measuring organic anion, sulphate (SO4) and base cation (Ca, Mg, K and Na) concentrations. In all study catchments, TOC was a major fraction of DOM, with much lower proportions of TON and DOP. Moreover, most of TOC and TON was in a dissolved form. The correlation between TOC and TON concentrations was strong and TOC concentrations explained 78% of the variation in TON concentrations in pristine headwater streams. In a subgroup of 20 headwater catchments with similar climatic conditions and low N deposition in eastern Finland, the proportion of peatlands in the catchment and the proportion of Norway spruce (Picea abies Karsten) of the tree stand had the strongest correlation with the TOC and TON concentrations and export. In Finnish river basins, TOC export increased with the increasing proportion of peatland in the catchment, whereas TON export increased with increasing extent of agricultural land. The highest DOP concentrations and export were recorded in river basins with a high extent of agricultural land and urban areas, reflecting the influence of human impact on DOP loads. However, the most important predictor for TOC, TON and DOP export in Finnish rivers was the proportion of upstream lakes in the catchment. The higher the upstream lake percentage, the lower the export, indicating organic matter retention in lakes. Molar TOC:TON ratio decreased from headwater catchments covered by forests and peatlands to the large river basins with mixed land use, emphasising the effect of the land use gradient on the stoichiometry of rivers. This study also demonstrated that the land use of the catchments is related to both organic and minerogenic acidity in rivers and pristine headwater streams. Organic anion dominated in rivers and streams situated in northern Finland, reflecting the higher extent of peatlands in these areas, whereas SO4 dominated in southern Finland and on western coastal areas, where the extent of fertile areas, agricultural land, urban areas, acid sulphate soils, and sulphate deposition is highest. High TOC concentrations decreased pH values in the stream and river water, whereas no correlation between SO4 concentrations and pH was observed. This underlines the importance of organic acids in controlling pH levels in Finnish pristine headwater streams and main rivers. High SO4 concentrations were associated with high base cation concentrations and fertile areas, which buffered the effects of SO4 on pH.
  • Sutela, Tapio; Vuori, Kari-Matti; Louhi, Pauliina; Hovila, Karoliina; Jokela, Sinikka; Karjalainen, Satu Maaria; Keinänen, Marja; Rask, Martti; Teppo, Anssi; Urho, Lauri; Vehanen, Teppo; Vuorinen, Pekka J.; Österholm, Peter (Suomen ympäristökeskus, 2012)
    Suomen ympäristö 14/2012
    Tähän kirjallisuuskatsaukseen on koottu kattavasti tietoa happamien sulfaattimaiden (HS-maat) vaikutuksista vesistöjemme vedenlaatuun, eliöstöön ja kalakuolemiin. Kirjallisuuskatsaus tehtiin Suomen ympäristökeskuksen koordinoiman CATERMASS-hankkeen yhteydessä laajan tutkijaryhmän yhteistyönä. Happamia sulfaattimaita muodostui Itämeren rehevissä rannikko-vesissä 4000–8000 vuotta sitten, kun mikrobit pelkistivät meriveden sulfaattia sulfidiksi. Maankohoamisen myötä sulfidisavikoita sisältäviä maita alettiin kuivata viljelyskäyttöön. Tällöin hapetusreaktiossa vapautuva rikki alkoi muodostaa maaperän veden kanssa rikkihappoa, joka liuottaa maaperästä myrkyllisiä metalleja, kuten alumiinia, kadmiumia ja kuparia. Runsaiden sateiden ja kevään sulamisvesien mukana happamuus ja metallit huuhtoutuvat vesistöön. Viime vuosikymmeninä lisääntyneen salaojituksen myötä peltojen kuivatus-syvyys on kasvanut lisäten samalla HS-maiden haitallisia vesistövaikutuksia. Happamuus ja siihen liittyvä metallien myrkyllisten olomuotojen runsastuminen aiheuttavat muutoksia vesistöjen kaikissa eliöryhmissä mukaan lukien kalat, pohjaeläimet, vesikasvit ja pohjalevät. Yksilötasolla on havaittu epämuodostumia, kuten vesihyönteistoukkien rakenne-vaurioita. Kalat yrittävät suojautua hengitysveden haitallisilta aineilta lisäämällä kidusten limaneritystä, jolloin hengitys vaikeutuu. Altistuminen happamuudelle ja metalleille haittaa kalojen lisääntymistä mm. viivästyttämällä munasolujen kypsymistä sekä vaikeuttamalla mätimunien hedelmöittymistä ja alkionkehitystä. Eliöyhteisötasolla HS-maiden vaikutus näkyy usein happamuudelle herkkien lajien tai lajiryhmien puuttumisena. Virtavesien kalalajeista happamuudelle herkkiä ovat esimerkiksi kivisimppu, made ja taimen, ja jokisuistojen pohjaeläinryhmistä esimerkiksi simpukat. HS-maiden aiheuttamista kalakuolemista joissa, järvissä, jokisuistoissa ja rannikkovesissä koottiin mahdollisimman kattava listaus, joka todentaa ongelmien keskittymistä Pohjanmaan alueelle. Pahiten happamuuden ja myrkyllisten metallien vaivaamat pikkujoet ovat olleet käytännössä kalattomia viimeisten vuosikymmenten ajan.
  • Mussaari, Ismo (Vesihallitus, 1974)
    Vesihallitus. Tiedotus 79
    Agricultute as a contributor to water pollution in Southwestern Finland.
  • Vuorenmaa, Jussi (Finnish Environment Institute, 2007)
    Monographs of the Boreal Environment Research 30
    The present work provides a regional-scale assessment of the changes in acidifying deposition in Finland over the past 30 years and the current pattern in the recovery of acid-sensitive lakes from acidification in relation to changes in sulphate deposition. This information is needed for documenting the ecosystem benefits of costly emission reduction policies and further actions in air pollution policy. The development of sulphate deposition in Finland reflects that of European SO2 emissions. Before the 1990s, reductions in sulphur emissions in Europe had been relatively small and sulphate deposition showed no consistent trends. Due to emission reduction measures that were then taken, sulphate deposition started to clearly decline from the late 1980s. The bulk deposition of sulphate has declined 40-60% in most parts of the country during 1990-2003. The decline in sulphate deposition exceeded the decline of base cation deposition, which resulted in a decrease in acidity and acidifying potential of deposition over the 1990s. Nitrogen deposition also decreased since the late 1980s, but less than that of sulphate, and levelling off during the 1990s. Sulphate concentrations in all types of lakes throughout Finland have declined from the early 1990s. The relative decrease in lake sulphate concentrations (average 40-50%) during 1990-2003 was rather similar to the decline in sulphate deposition, indicating a direct response to the reduction in deposition. There are presently no indications of elevated nitrate concentrations in forested headwater lakes. Base cation concentrations are still declining in many lakes, especially in south Finland, but to a lesser extent than sulphate allowing buffering capacity (alkalinity) to increase. The recovery has been strongest in lakes in which sulphate has been the major acidifying agent, and recovery has been the strongest and most consistent in lakes in south Finland. The recovery of lakes in central Finland and north Finland is not as widespread and strong as observed in south. Many catchments, particularly in central Finland, have a high proportion of peatlands and therefore high TOC concentrations, and runoff-induced surges of organic acids have been an important confounding factor suppressing the recovery of pH and alkalinity in these lakes. Chemical recovery is progressing even in the most acidified lakes, but the buffering capacity of many lakes is still low and still sensitive to acidic input. Chemical recovery is resulting in biological recovery with populations of acid-sensitive fish species increasing. Increasing TOC concentrations are indicated in small forest lakes in Finland, which appear to be related to decreasing sulphate deposition and improved acid-base status of the soil. A new challenge is climate change with potential trends in temperature, precipitation and runoff, which are expected to affect future chemical and biological recovery from acidification. The potential impact of mobilization and leaching of organic acids may become particularly important in Finnish conditions. Long-term environmental monitoring has evidently shown the success of international emission abatement strategies. The importance and value of integrated monitoring approach including physical, chemical and biological variables is clearly indicated, and continuous environmental monitoring is needed as a scientific basis for further actions in air pollution policy. The effect of climate change will increase data requirements, and should be taken into account when assessing long-term surface water quality and developing future monitoring networks, due to more complex processes involved.