Browsing by Subject "water quality"

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  • Västilä, Kaisa; Väisänen, Sari; Koskiaho, Jari; Lehtoranta, Virpi; Karttunen, Krister; Kuussaari, Mikko; Järvelä, Juha; Koikkalainen, Kauko (MDPI, 2021)
    Sustainability 13, 16
    Conventional dredging of ditches and streams to ensure agricultural drainage and flood mitigation can have severe environmental impacts. The aim of this paper is to investigate the potential benefits of an alternative, nature-based two-stage channel (TSC) design with floodplains excavated along the main channel. Through a literature survey, investigations at Finnish field sites and expert interviews, we assessed the performance, costs, and monetary environmental benefits of TSCs in comparison to conventional dredging, as well as the bottlenecks in their financing and governance. We found evidence supporting the expected longer-term functioning of drainage as well as larger plant and fish biodiversity in TSCs compared to conventional dredging. The TSC design likely improves water quality since the floodplains retain suspended sediment and phosphorus and remove nitrogen. In the investigated case, the additional value of phosphorus retention and conservation of protected species through the TSC design was 2.4 times higher than the total costs. We demonstrate how TSCs can be made eligible for the obligatory vegetated riparian buffer of the European Union agri-environmental subsidy scheme (CAP-AES) by optimising their spatial application with respect to other buffer measures, and recommend to publicly finance their additional costs compared to conventional dredging at priority sites. Further studies on biodiversity impacts and long-term performance of two-stage channels are required.
  • Bhattacharjee, Joy; Marttila, Hannu; Launiainen, Samuli; Lepistö, Ahti; Kløve, Bjørn (Elsevier, 2021)
    Science of The Total Environment 779 (2021), 146419
    Maintaining and improving surface water quality requires knowledge of nutrient and sediment loads due to past and future land-use practices, but historical data on land cover and its changes are often lacking. In this study, we tested whether land-use-specific export coefficients can be used together with satellite images (Landsat) and/or regional land-use statistics to estimate riverine nutrient loads and concentrations of total nitrogen (TN), total phosphorus (TP), and suspended solids (SS). The study area, Simojoki (3160 km2) in northern Finland, has been intensively drained for peatland forestry since the 1960s. We used different approaches at multiple sub-catchment scales to simulate TN, TP, and SS export in the Simojoki catchment. The uncertainty in estimates based on specific export coefficients was quantified based on historical land-use changes (derived from Landsat data), and an uncertainty boundary was established for each land-use. The uncertainty boundary captured at least 60% of measured values of TN, TP, and SS loads or concentrations. However, the uncertainty in estimates compared with measured values ranged from 7% to 20% for TN, 0% to 18% for TP, and 13% to 43% for SS for different catchments. Some discrepancy between predicted and measured loads and concentrations was expected, as the method did not account for inter-annual variability in hydrological conditions or river processes. However, combining historical land-use change estimates with simple export coefficients can be a practical approach for evaluating the influence on water quality of historical land-use changes such as peatland drainage for forest establishment.
  • Hashemi, Fatemeh; Pohle, Ina; Pullens, Johannes W. M; Tornbjerg, Henrik; Kyllmar, Katarina; Marttila, Hannu; Lepistö, Ahti; Klove, Bjorn; Futter, Martyn; Kronvang, Brian (MDPI, 2020)
    Water 12 6 (2020)
    Optimal nutrient pollution monitoring and management in catchments requires an in-depth understanding of spatial and temporal factors controlling nutrient dynamics. Such an understanding can potentially be obtained by analysing stream concentration–discharge (C-Q) relationships for hysteresis behaviours and export regimes. Here, a classification scheme including nine different C-Q types was applied to a total of 87 Nordic streams draining mini-catchments (0.1–65 km2). The classification applied is based on a combination of stream export behaviour (dilution, constant, enrichment) and hysteresis rotational pattern (clock-wise, no rotation, anti-clockwise). The scheme has been applied to an 8-year data series (2010–2017) from small streams in Denmark, Sweden, and Finland on daily discharge and discrete nutrient concentrations, including nitrate (NO3−), total organic N (TON), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP). The dominant nutrient export regimes were enrichment for NO3− and constant for TON, DRP, and PP. Nutrient hysteresis patterns were primarily clockwise or no hysteresis. Similarities in types of C-Q relationships were investigated using Principal Component Analysis (PCA) considering effects of catchment size, land use, climate, and dominant soil type. The PCA analysis revealed that land use and air temperature were the dominant factors controlling nutrient C-Q types. Therefore, the nutrient export behaviour in streams draining Nordic mini-catchments seems to be dominantly controlled by their land use characteristics and, to a lesser extent, their climate.
  • Aaltonen, Heidi; Tuukkanen, Tapio; Palviainen, Marjo; Laurén, Annamari (Ari); Tattari, Sirkka; Piirainen, Sirpa; Mattsson, Tuija; Ojala, Anne; Launiainen, Samuli; Finér, Leena (2021)
    Understanding the anthropogenic and natural factors that affect runoff water quality is essential for proper planning of water protection and forest management, particularly in the changing climate. We measured water quality and runoff from 10 unmanaged and 20 managed forested headwater catchments (7-12,149 ha) located in Finland. We used linear mixed effect models to test whether the differences in total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) export and concentrations observed can be explained by catchment characteristics, land use, forest management, soil fertility, tree volume and hydrometeorological variables. Results show that much of variation in TOC, TN and TP concentrations and export was explained by drainage, temperature sum, peatland percentage and the proportion of arable area in the catchment. These models explained 45-63% of variation in concentrations and exports. Mean annual TOC export in unmanaged catchments was 56.4 +/- 9.6 kg ha(-1) a(-1), while in managed it was 79.3 +/- 3.3 kg ha(-1) a(-1). Same values for TN export were 1.43 +/- 0.2 kg ha(-1) a(-1) and 2.31 +/- 0.2 kg ha(-1) a(-1), while TP export was 0.053 +/- 0.009 kg ha(-1) a(-1) and 0.095 +/- 0.008 kg ha(-1) a(-1) for unmanaged and managed, respectively. Corresponding values for concentrations were: TOC 17.7 +/- 2.1 mg L-1 and 28.7 +/- 1.6 mg L-1, for TN 420 +/- 45 mu g L-1 and 825 +/- 51 mu g L-1 and TP 15.3 +/- 2.3 mu g L-1 and 35.6 +/- 3.3 mu g L-1. Overall concentrations and exports were significantly higher in managed than in unmanaged catchments. Long term temperature sum had an increasing effect on all concentrations and exports, indicating that climate warming may set new challenges to controlling nutrient loads from catchment areas.
  • Lehtoranta, Virpi; Louhi, Pauliina (Elsevier Science, 2021)
    Environmental Science & Policy 124, 226-234
    Non-market values pose a challenge in decision making. In a contribution to the issue, the study assesses the potential positive impact on residents’ wellbeing of improving the ecological status of water bodies making up the Saarijärvi watercourse in Central Finland, a region with numerous Natura areas. The benefits provided by the aquatic environment and the factors affecting them were assessed using the contingent valuation method (CVM). A split-sample design made it possible to analyse expressed uncertainty with two payment vehicles: in one, the question of uncertainty was included in the willingness-to-pay (WTP) questions (multiple bounded discrete choice, MBDC); in the other, it was queried separately after the payment card (PC) question. Where respondents saw added value in Natura 2000 sites and received new information on water management, they experienced increased wellbeing from improved water quality. Perceived importance of sustainable hydropower and water regulation also figured in a desire to improve the ecological status of waters in the region. The results show that there is a noticeable positive WTP among residents (N = 473) for improved water status and that estimated WTP differs according to uncertainty: mean WTP every year per individual fell in the range EUR 29.70 to EUR 75.50. Improvement of water status and protection of Natura 2000 sites were found to be mutually reinforcing goals. Higher net social benefits could be realized if implementation of the applicable directives were more closely coupled to regional planning.
  • Popin, Rafael Vicentini; Delbaje, Endrews; de Abreu, Vinicius Augusto Carvalho; Rigonato, Janaina; Dorr, Felipe Augusto; Pinto, Ernani; Sivonen, Kaarina; Fiore, Marli Fatima (2020)
    The bloom-forming cyanobacterium Nodularia spumigena CENA596 encodes the biosynthetic gene clusters (BGCs) of the known natural products nodularins, spumigins, anabaenopeptins/namalides, aeruginosins, mycosporin-like amino acids, and scytonemin, along with the terpenoid geosmin. Targeted metabolomics confirmed the production of these metabolic compounds, except for the alkaloid scytonemin. Genome mining of N. spumigena CENA596 and its three closely related Nodularia strains-two planktonic strains from the Baltic Sea and one benthic strain from Japanese marine sediment-revealed that the number of BGCs in planktonic strains was higher than in benthic one. Geosmin-a volatile compound with unpleasant taste and odor-was unique to the Brazilian strain CENA596. Automatic annotation of the genomes using subsystems technology revealed a related number of coding sequences and functional roles. Orthologs from the Nodularia genomes are involved in the primary and secondary metabolisms. Phylogenomic analysis of N. spumigena CENA596 based on 120 conserved protein sequences positioned this strain close to the Baltic Nodularia. Phylogeny of the 16S rRNA genes separated the Brazilian CENA596 strain from those of the Baltic Sea, despite their high sequence identities (99% identity, 100% coverage). The comparative analysis among planktic Nodularia strains showed that their genomes were considerably similar despite their geographically distant origin.
  • Kokkonen, Tom (2013)
    Suomessa jääpeite kattaa vesistöjä 3 - 7 kuukautta vuodessa. Jokien jääolosuhteilla on suuri merkitys jokivarsien asukkaille ja teollisuuslaitoksille. Jokien jäätymiseen liittyvät ongelmat aiheuttavat suuria taloudellisia menetyksiä ja ympäristövahinkoja, vaikka niitä pyritäänkin ehkäisemään erilaisilla jääntorjuntamenetelmillä ja vesistönkäyttö- ja tulvantorjuntatoimenpiteillä. Kymijoella suurin ongelma on suppojää, joka aiheuttaa vahinkoja lähes joka vuosi. Kymijoki sijaitsee Kaakkois-Suomessa ja laskee Itämerelle Suomenlahteen. Kymijoen valuma-alueen pinta-ala on 37 107 km2, joka kattaa lähes 11 % koko Suomen pinta-alasta. Keskimääräinen virtaama joen pääuomassa on 283 m3/s. Kymijoki on valuma-alueeltaan ja virtaamaltaan maamme neljänneksi suurin joki. Tämän tutkimuksen ensimmäisenä tavoitteena oli valita sopivat mittauspisteet Kymijoen pääuomasta, sen kaikista haaroista ja lähtöjärvistä sekä tutkia niiden sopivuutta kuvaamaan Kymijoen olosuhteita. Kymijoen veden laatua ja jääoloja tutkittiin kenttämittauksina talvella 2011–2012. Toisena tavoitteena oli koostaa tehdyistä mittauksista kattava kuva Kymijoen jääolosuhteista ja veden laadusta talviaikana. Näitä tietoja verrattiin Kymijoen vesi- ja ympäristö ry:n vedenlaatututkimuksiin, Suomen ympäristökeskuksen virtaamahavaintoihin ja Ilmatieteen laitoksen säähavaintoihin. Kymijoen eri mittauspisteiden välillä oli hyvin paljon eroja jääkannen peittävyydessä ja rakenteessa, johtuen erilaisista olosuhteista ja Kymijoella käytetyistä jääntorjuntakeinoista. Osalla mittauspisteistä oli reunajäätä vain vähän tai ei jäätä ollenkaan ja osalla mittauspisteistä oli koko joen kattava kiinteä jääkansi. Jään paksuus eri mittauspisteillä vaihteli 0-55 cm välillä. Veden laatu oli koko Kymijoella kohtuullisen hyvä, vaikkakin eri osissa jokea oli selvästi havaittavissa vaihtelua. Happitilanne oli koko joella kohtuullisen hyvä ja suurimmat hapen kyllästysasteet olivat odotetusti hyvin vettä hapettavan koskijakson jälkeen. Sameudessa ja kiintoainespitoisuudessa oli huomattavan suurta vuodenaikaisvaihtelua. Lumen sulaminen keväällä ja runsaat sateet loppuvuodesta 2011 nostivat sameusarvoja selvästi. Perustuotannon vaikutus oli selvästi havaittavissa kesäkuun korkeissa kiintoainespitoisuuksissa. Kymijoen pH oli koko tarkastelujaksolla lähes neutraalilla tasolla. Kevään sulamisvesien happamoittava vaikutus ja perustuotannon pH:ta kohottava vaikutus olivat kuitenkin havaittavissa. Jätevesien sähkönjohtavuutta nostava vaikutus oli selvästi havaittavissa Kymijoella. Valon sironta ja näin ollen partikkelien määrä Kymijoella lisääntyi joen alajuoksulle päin. Kymijoen yläosien järvissä vesi oli huomattavasti puhtaampaa kuin varsinaisessa joessa ja myös partikkelien sirontavaikutukset olivat häviävän pieniä. Jään rakenteessa tai peittävyydessä ei havaittu merkittäviä eroja, jotka johtuisivat siirtymisestä yläjuoksulta alajuoksulle, vaan erot johtuivat lähinnä hyvin erilaisista virtausolosuhteista ja Kymijoella käytetyistä jääntorjuntakeinoista. Jääpuomien vaikutusta jääkanteen ei havaittu kaikilla mittauspisteillä, mutta muutamilla mittauspisteillä vaikutus oli merkittävä jääkannen rakenteeseen ja peittävyyteen. Veden laatu oli koko Kymijoella kohtuullisen hyvä, mutta se muuttui selvästi huonommaksi siirryttäessä alajuoksulle päin. Veden laadun muutokset aiheutuivat joen alajuoksulla sijaitsevista teollisuuslaitoksista ja vedenpuhdistamoista. Kymijoen kahden päähaaran välillä ei havaittu merkittäviä eroja. Veden laadussa ei havaittu kerroksellisuutta johtuen virtauksen turbulenttisesta luonteesta.
  • Nieminen, Mika; Sarkkola, Sakari; Hasselquist, Eliza Maher; Sallantaus, Tapani (Kluwer Academic Publishers, 2021)
    Water, Air, & Soil Pollution 232 (2021), 371
    Contradictory results for the long-term evolution of nitrogen and phosphorus concentrations in waters discharging from drained peatland forests need reconciliation. We gathered long-term (10–29 years) water quality data from 29 forested catchments, 18 forestry-drained and 11 undrained peatlands. Trend analysis of the nitrogen and phosphorus concentration data indicated variable trends from clearly decreasing to considerably increasing temporal trends. While the variations in phosphorus concentration trends over time did not correlate with any of our explanatory factors, trends in nitrogen concentrations correlated positively with tree stand volume in the catchments and temperature sum. A positive correlation of increasing nitrogen concentrations with temperature sum raises concerns of the future evolution of nitrogen dynamics under a warming climate. Furthermore, the correlation with tree stand volume is troublesome due to the generally accepted policy to tackle the climate crisis by enhancing tree growth. However, future research is still needed to assess which are the actual processes related to stand volume and temperature sum that contribute to increasing TN concentrations.
  • Nieminen, Mika; Sarkkola, Sakari; Haahti, Kersti; Sallantaus, Tapani; Koskinen, Markku; Ojanen, Paavo (Suoseura, 2020)
    Suo - tutkimusartikkelit
    Viime vuosina julkaistujen tutkimusten mukaan metsäojitettujen soiden vesistö kuormituksen epäillään olevan moninkertaisesti aiemmin arvioitua suurempaa. Syynä tähän on se, että kuormitusta syntyy aiemmista käsityksistä poiketen silloinkin, kun ojitusalueilla ei ole vuosikausiin tehty mitään toimenpiteitä. Tässä työssä arvioitiin metsäojitusalueilta syntyvä vesistökuormitus ottamalla huomioon sekä tämä nykyisistä metsätaloustoimenpiteistä riippumaton ”ojituslisä” että kunnostusojituksen, lannoituksen ja hakkuiden aiheuttama kuormitus. Tehdyn arvion mukaan metsätaloudesta ojitetuilla soilla syntyy Suomessa vuosittain typpikuormitusta noin 8500 Mg ja fosforikuormi tusta 590 Mg. Kun ojituslisä otetaan huomioon, typpikuormitus on noin 18-kertainen ja fosforikuormitus 6–7-kertainen aiempiin vain eri toimenpiteiden kuormitukset huomioon ottaviin arvioihin verrattuna. Vesiensuojelun kannalta oleellista olisi selvittää, mitkä tekijät ojitusalueilla aiheuttavat ojituslisän muodossa tapahtuvaa pysyvää kuormitusta ja mitä tämän kuormituksen torjumiseksi on tehtävissä.
  • Laurén, Annamari (Ari); Guan, Mingfu; Salmivaara, Aura; Leinonen, Antti; Palviainen, Marjo; Launiainen, Samuli (2021)
    Responsible forest management requires accounting for adverse environmental effects, such as increased nutrient export to water courses. We constructed a spatially-distributed nutrient balance model NutSpaFHy that extends the hydrological model SpaFHy by introducing a grid-based nutrient balance sub-model and a conceptual solute transport routine to approximate total nitrogen (N) and phosphorus (P) export to streams. NutSpaFHy uses openly-available Multi-Source National Forest Inventory data, soil maps, topographic databases, location of water bodies, and meteorological variables as input, and computes nutrient processes in monthly time-steps. NutSpaFHy contains two calibrated parameters both for N and P, which were optimized against measured N and P concentrations in runoff from twelve forested catchments distributed across Finland. NutSpaFHy was independently tested against six catchments. The model produced realistic nutrient exports. For one catchment, we simulated 25 scenarios, where clear-cuts were located differently with respect to distance to water body, location on mineral or peat soil, and on sites with different fertility. Results indicate that NutSpaFHy can be used to identify current and future nutrient export hot spots, allowing comparison of logging scenarios with variable harvesting area, location and harvest techniques, and to identify acceptable scenarios that preserve the wood supply whilst maintaining acceptable level of nutrient export.
  • Gaudig, G.; Krebs, M.; Prager, A.; Wichmann, S.; Barney, M.; Caporn, S. J. M.; Emmel, M.; Fritz, C.; Graf, M.; Grobe, A.; Pacheco, S. Gutierrez; Hogue-Hugron, S.; Holztraeger, S.; Irrgang, S.; Kämäräinen, A.; Karofeld, E.; Koch, G.; Koebbing, J. F.; Kumar, S.; Matchutadze, I.; Oberpaur, C.; Oestmann, J.; Raabe, P.; Rammes, D.; Rochefort, L.; Schmilewksi, G.; Sendzikaite, J.; Smolders, A.; St-Hilaire, B.; van de Riet, B.; Wright, B.; Wright, N.; Zoch, L.; Joosten, H. (2017)
    Sphagnum farming - the production of Sphagnum biomass on rewetted bogs - helps towards achieving global climate goals by halting greenhouse gas emissions from drained peat and by replacing peat with a renewable biomass alternative. Large-scale implementation of Sphagnum farming requires a wide range of know-how, from initial species selection up to the final production and use of Sphagnum biomass based growing media in horticulture. This article provides an overview of relevant knowledge accumulated over the last 15 years and identifies open questions.
  • Jaakkola, Sauli (Helsingfors universitet, 2013)
    Assessing and avoiding environmental impact of agriculture and forestry has become more and more important during recent years. In Finland, half of the phosphorus load and nearly 40 % of the nitrogen load in the water system is caused by agriculture and forestry. Traditionally water quality monitoring has been carried out with manual water sampling and laboratory analyses. The problem with manual sampling is low amount of samples. Continuously working water quality sensors have been used for a relatively short time, which is why continuous water quality monitoring needs more research. The objective of the study is to clarify the feasibility of optical sensors in monitoring water quality and nutrient loading in an agricultural and forest management area. The study was carried out in three monitoring stations of the Savijoki catchment in Southwest Finland. Two of the stations were identically equipped and were located in forested subcatchments. A third station was located at the Savijoki catchment discharge point, making it possible to study how sensors work in different water qualities. According to the study, monitoring with continuously working sensors will result in more accurate nutrient loading estimates. With sensors used in the study it is also possible to draw conclusions about dynamics between run-off and nutrient concentrations in water. A prerequisite for successful monitoring is utilizing the appropriate sensors in the correct location. For example, low nitrate levels in water in forested areas have to be taken into consideration when choosing sensors. During the monitoring it is important to actively keep track of the quality of data and to check that sensors are working properly. Water quality sensors always need good calibration and control water samples from the entire concentration range. Sensors also have to be equipped with an automatic cleaning mechanism.
  • Voigt, H.-R. (Karolinum-Nakladatelstvi Univerzity Karlovy, 2000)
  • Stuart, Elliot (Helsingfors universitet, 2013)
    The primary characteristic of urbanisation is the addition of hard surfaces to catchments, which affects water and habitat quality in urban streams and alters natural hydrological processes by reducing infiltration, evapotranpiration and efficiently conveying storm runoff to streams, gathering a variety of urban polluants along the way. This is typical of the 'urban stream syndrome'. Catchment imperviousness (especially Effective Impervious Area or percent connectivity) can be used as one of the primary indicators of the severity of this phenomenon. This research was initiated through a collaboration between the City of Helsinki and the University of Helsinki to determine the baseline water quality of Hakuninmaanoja, a small urban stream in Helsinki, Finland, and the imperviousness of its catchment, where a pilot ecological housing development 'Kuninkaantammi' (KUNTA) will be built beginning in 2013. The purpose of the project is to assess the current characteristics of the catchment prior to the development in the headwaters of the stream. An automatic water quality monitoring station was built on the lower part of the stream approximately 200m upstream of its junction with Mätäjoki, the second largest river of Helsinki. Water Sensitive Urban Design can be used as part of a holistic stormwater treatment train to limit newly created imperviousness, and minimise the connectivity of the necessary remainder, allowing stormwater runoff to be reused, infiltrated and treated through soil media, or slowed down enough to attenuate the urban hydrograph. Some of these features such as raingardens, green roofs and detention ponds will be included in the KUNTA development for this purpose. A detailed calculation of catchment imperviousness was completed via field survey and land use categorization methods. Total Impervious Area (TIA) was determined to be 22%, Effective Impervious Area 15% and catchment wide runoff coefficient given by land use categorisation method to be 0.32. TIA is expected to increase to 30% following development of KUNTA, however EIA is not expected to increase in proportion with TIA due to planned Water Sensitive Urban Design features. Yearly runoff volumes based on each method of calculating imperviousness were estimated, as well as for the future following KUNTA development. Water quality in the stream currently is quite satisfactory in relation to other streams in Helsinki, however the urban stream syndrome is already evident with particular concern regarding temperature, sediment and peak flow fluctuations. Effective Impervious Area should be used in urban planning of new and existing developments rather than TIA because it will give much greater accuracy of runoff volumes and infiltration rates by taking into account unconnected impervious surfaces. Strengthening local solutions to reduce connectivity should be a municipal priority. Water quality monitoring will continue at the site until after KUNTA has been built, and further research should focus on determining the technical performance of stormwater Best Management Practices (BMPs) at the site.