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Drainage-induced diffuse pollution and erosion are key water quality problems in peatland forestry. A major part of the pollutant load is transported during peak runoff periods after snowmelt or intense rainfall. This study investigated possibilities to increase retention time of runoff waters in drained peat- land catchments on purpose to diminish peak runoff and improve settling conditions of suspended solids (SS). To create retention, a peak runoff control (PRC) structure was developed and its functioning, dimen- sioning and practical applications were studied in five partly or completely ditch-drained catchments in Central Finland. The method reduced runoff peaks by 10-73% or 5.07-57.63 l −1 s −1 km −2 , and func- tioned especially well during largest runoff peaks. The effectiveness of the PRC method depended on (i) catchment topography (slope) and available detention volume, (ii) dimensioning and location of the PRC structure, and (iii) runoff rates. The PRC structure is cheap and can easily be created with forest drainage machinery during the ditching and ditch network maintenance operations. Different issues relating to the structural design, water quality benefits, and impacts on forestry are discussed. © 2010 Elsevier B.V. All rights reserved.

Agriculture is a major economic sector in sub-Saharan African (SSA) countries, where it contributes 32 percent of the gross domestic product (GDP) and employs 65 percent of the population. However, SSA countries are farming only a small percentage of their potential cultivable area and are using only a fraction of their renewable water resources. Moreover, despite the importance of land and water resources in SSA, especially in rural areas, there has been little research on their potential. In this study, an index was developed to assess the potential for agriculture, considering renewable water availability of both surface water and groundwater. The index-based approach was then used to assess the potential increase in arable land area in 15 selected SSA countries. The selected countries were classified using the index, based on the availability of renewable water resources nationwide. We also assessed the future water demand by employing three scenarios and combining different rain-fed and irrigated options. The results show that, except for Zimbabwe, the current available surface water or groundwater resources could be sufficient to farm all of the potential cultivable areas in the selected countries when both rain-fed and irrigated systems are fully operational. The findings also indicate that targeted infrastructure projects (e.g., reservoirs, channels), crop management, and water saving techniques could improve surface and groundwater availability in the SSA region.

Summary Erosion and suspended sediment transport dynamics were studied in the open water season (April–November) of three consecutive years in a drained peatland forest. Discharge and suspended solids were monitored continuously and sediment properties surveyed with individual samples. Sediment transport dynamics were studied using statistical methods and plotted as hysteresis, duration and effective discharge plots. Sediment rating curves for averaged daily data for months and total season were established to seek empirical sediment yield predictive model(s). The discharge patterns in the study catchment were dominated by peak runoff events resulting from snowmelt and intensive rainfall. Fluctuations in suspended sediment concentrations (SSC) were associated with discharge fluctuations. Sediment transport varied markedly during the study months and years, with organic sediment playing an important role. The present study demonstrates sediment transport processes and reveals the underlying mechanics operating in forested peatland areas. These include inter-storm sediment storage, bank collapse and the role of peak runoff rate on erosion in peak flow events. Sediment availability in drainage network channels also played a major role in erosion and SSC. The results indicate that summer runoff peaks can be a dominant element controlling annual sediment yield, partly contradicting previous studies in drained peatland areas identifying spring snowmelt as the dominant element. Sediment yield prediction with the empirical sediment-transport rating curve gave good regressions for some data, but simple regression models were not adequate to provide accurate annual predictions.

Retention of stormwater can in theory reduce peak flows, sediment and nutrient transport. This study presents results of peak runoff control (PRC) as a water protection method to decrease sediment and nutrient loads from drained peatland forestry in boreal conditions. Peak runoff rate and peak concentrations were reduced. The PRC method reduced suspended solids (SS) load (86%) by reducing flow velocities and improving settling conditions in the ditch network. The method had a considerable effect on SS-bound nutrients, reducing total nitrogen (Ntot) load by 65% and total phosphorus (Ptot) load by 67%. Reductions in velocity resulted in smaller particle size distributions in transported SS. No effect on groundwater elevation was observed and drainage conditions for forestry were maintained. The results clearly show that the PRC method can be used efficiently in peatland forestry as a water protection method to improve water quality.

Peatland drainage results in several environmental impacts such as release of greenhouse gas to the atmosphere and leaching of nutrients to watercourses. These hazardous environmental effects can partly be controlled with soil management, and different drainage and remediation practices. Grading is a new method developed for soils with low conductivity suffering from poor drainage, water logging and ice. The soil surface is graded towards the ditch to increase surface runoff and drainage. The present study compares environmental effects of peatland grading compared to traditional intense pipe drainage. Detailed measurements of hydrology, climate, leaching and gas emissions were carried out at adjacent drainage areas with grass cultivation. Additional measurements were made at plots that were abandoned, cultivated with perennial crops, and remained as pristine peatlands. The results show that the leaching of nutrients is highest from pipe drainage. Climate gas emission was considerably higher at all managed sites than from the reference pristine site. Drainage, soil hydrology and soil nutrient status seemed to control gas emissions. The gas emissions were higher than assumed for Norwegian cold conditions. The results confirm observations made on peat soils in other climatic regions. The highest emissions of CO2 were observed when the soil temperature was high and groundwater table low. The N2O emission showed a large variation with no clear pattern. However, at some locations it peaked after a dry period when NO3–N was leached. More CH4 was emitted from the intensively drained site than the graded site, but more CO2 was emitted from the graded site. The difference in leaching and emission properties is partly due to differences in near surface hydrology. At grade sites, a faster runoff response to rainfall occur probably due to shallow throughfall or overland flow which provides better drainage. The abandoned peat field no longer in cultivation continued to leach greenhouse gases in a same way as the cultivated sites.

Summary A robust conceptual and statistical approach is presented for the study of ground water table fluctuations with precipitation and temperature as input variables. A conceptual hydrological model was developed to generate daily rainfall, snowmelt and evapotranspiration values and these values were cross-correlated with observed ground water levels to find representative time lags and significant correlations to describe the ground water system. A statistical model linking rainfall, snowmelt, evapotranspiration and ground water level was then developed and validated for an unconfined esker aquifer in boreal environment in central Finland. The model predicted very well fluctuation of ground water level and timing of the minimum and maximum water levels. A future climate change scenario for the years 2010–2039 was subsequently simulated. The simulation indicates higher ground water levels in milder winter climate. This is due to increase in winter recharge. The model provides a new tool to assess the impacts and address the uncertainties related to climate variation and change in complex ground water systems in cold regions with snow cover.

A literature review of the impacts of anticipated climate change on unconfined aquifers is presented, along with a conceptual framework for evaluating the complex responses of surface and subsurface hydrology to climate variables in cold regions. The framework offers a way to conceptualize how changes in one component of the system may impact another by delineating the relationships among climate drivers, hydrological responses, and groundwater responses in a straight-forward manner. The model is elaborated in the context of shallow unconfined aquifers in the boreal environment of Finland. In cold conditions, climate change is expected to reduce snow cover and soil frost and increase winter floods. The annual surface water level maximum will occur earlier in spring, and water levels will decrease in summer due to higher evapotranspiration rates. The maximum recharge and groundwater level are expected to occur earlier in the year. Lower groundwater levels are expected in summer due to higher evapotranspiration rates. The flow regimes between shallow unconfined aquifers and surface water may change, affecting water quantity and quality in the surface and groundwater systems.

Suspended sediments have a clear impact on fluvial water quality and aquatic habitats. As the concentrations are highly variable, continuous measurement offers a good way to provide accurate and precise values of sediment concentration and yield. However, there is a lack of information regarding the effect of organic peat particles, which typically appear in boreal fluvial systems. In the present study, the effect of different types of suspended sediments on calibration of a turbidity meter and an acoustic Doppler velocimetry (Triton-ADV) was studied in laboratory conditions. The measurements were performed using particulate organic peat, clay and silt with several concentrations ranging from clear water to 3500 mg L⁻¹. The present study primarily provides organic peat sediment calibration data for used sensors. Regression equations were developed for the different sediment. The results indicate that particle size, shape, concentration and sediment type have an effect on calibration. When the turbidity and the ADV calibration were performed for different particle size groups, sediment types and concentrations, the calibration and suspended solids calculation error was reduced. For the turbidity sensor used, the reliable upper continuous measurement limit for clay, peat and silt sediments was found to be at 1000, 2500 and 3500 mg L⁻¹, respectively. The ADV-sensor was noticed to be reliable only with fine particles. The results enable easy and first step calibration and error assessment for automatic turbidity and acoustic monitoring of the suspended sediment quality typically present in headwater fluvial systems. This study can be used to evaluate the effect of different sediments on turbidity and ADV-measuring error and reliability during changing particles size distributions, characteristics and concentrations. The laboratory-based approach used in this study indicates that the shape of organic peat particles has an influence on sensor calibration, especially when suspended sediment concentrations are high. Copyright © 2009 John Wiley & Sons, Ltd.

Four treatment peatlands were studied in Northern Finland in order to determine peat P, Al and Fe concentration distributions and to find removal parameters for nutrient modelling. The sites had been under loading for 10–16 years. About 20 peat samples for analyses of oxalate-extractable and total P, Al and Fe were collected from the depth 0–10 cm in each peatland. The peat P concentration ranged from 0.097 mg g−1 to 14 mg g−1 being 1.7 mg g−1on average. P accumulated in preferential flow path areas. Although P concentrations were locally high, DSSP (the index of potential soil P release from peat to water) was very low in all studied peatlands, indicating that peat was not saturated by phosphorus. The results indicate that Al-based precipitation chemicals increase substantially P retention capacity of peatland and maintain a stabile P reduction in spite of varying P loads. The results also show long-term phosphorus accumulation in peatlands polishing municipal wastewater from activated sludge treatment. The regression analyses showed that k-value for N removal depends on N loading and hydraulic loading. The first-order area model together with regression analysis of the rate constant result in a good agreement between observed and calculated nitrogen concentration. The NH4-N loading to the peatland should be below 0.10 mg m2 d−1 in order to achieve a high reduction of 70%.

The purpose of this research was to evaluate peak runoff control as a water protection method to reduce sediment and nutrient loads. Increased eutrophication of surface waters and risk of floods demands cost effective methods to reduce pollutant input and risks of flooding. With the peak runoff control it is possible to cut the main peaks and store the runoff water temporarily in ditches. The method decreases the suspended solids (SS) and nutrient loads by reducing flow velocities, and improving the settling of sediment particles. The method was tested in two heavily drained adjacent peat harvesting areas suffering considerable erosion. The peak flows were cut by 27–87%, the SS load by 61–94%, the total nitrogen ( Ntot ) by 45–91%, and the total phosphorus ( Ptot ) load by 47–88%. The peak runoff control method operated most effectively during extreme events when most of the SS load is transported. A detailed particle analysis of runoff water showed that water detention reduced the median particle size of...

In this study, we evaluated flow structure, effective flow area (A(eff)) and effective porosity (theta(eff)) in three peatlands using the stable isotope (18)O/(16)O ratio and tracer tests. We also applied the readily available groundwater modelling MODFLOW code for wetland flow modelling and simulated in one study site how the hydraulic performance of the wetland will be improved by changing the design of the distribution ditch. Preferential flow paths occurred in all three studied wetlands and A(eff) varied from 40% to 90% of total wetland area while theta(eff) was 0.75-0.99. Constructed flow models accurately simulated the hydraulic head across wetlands (r(2)=0.95-0.99). Similarities between the flow models and the stable isotope distributions observed in this study suggest possibilities in using MODFLOW to design peatlands. The improvement of the inlet ditch configuration (ditch length/wetland width0.45) can prevent or reduce short-circuiting and dead zones in peatlands treating wastewater.

Summary The understanding of flow processes is one of the key elements in evaluating treatment efficiency in constructed wetlands. This study use a new method based on analysis of stabile oxygen and hydrogen isotope distributions in surface water in order to find water flow pathways in a treatment system established on a natural peatland in Ruka, Finland. The 18 O/ 16 O distributions of surface water samples were analysed in three field campaigns (2002, 2004, and 2005) and 2 H/ 1 H distribution in one field campaign (2002). Two conventional tracer (KBr and KI) tests and a tracer (NaCl) test in ground water tubes were conducted to study residence times and soil water flow characteristics. Online registration of electrical conductivity and temperature were used to analyse the NaCl experiment. The results showed clear spatial differences in 18 O/ 16 O distributions that were similar in each field campaign. Both 18 O/ 16 O and 2 H/ 1 H also varied clearly with depth until 40 cm. The results indicate that a strong preferential pathway exists in the wetland and that the water flows mainly in the top of peat layer. The observed flow path was the reason for the varying NH 4 -N distribution showing that a large potential area for nutrient removal is not used. The results show that the isotope method can be used to evaluate the water flow structure in peatlands and determinate the active flow area for wastewater purification. Along with the traditional tracer test the method can be used to estimate the active flow volume. A modification to the potential residence time equation is proposed by including active flow area, flow depth and an effective porosity.

Constructed wetlands (CWs) are commonly established to reduce pollution load from different sources. In environmental permits, the load remaining after CW purification is typically estimated through concentration and flow measurements. This load monitoring is often carried out using long water quality sampling intervals, which causes uncertainty in load estimation. In this study, a large suspended solids (SSs) and dissolved organic carbon (DOC) dataset was used to quantify the uncertainty in load estimation at the inlet and outlet of a CW with different sampling frequencies (sampling every 1, 2, 3 or 4 weeks). A method to reduce the uncertainty by dividing the CW flow duration curve (FDC) into four equal categories and assigning mean/median concentration for each category according to the measured concentrations was also tested. The results showed that estimated SS load was associated with considerable uncertainty and that this uncertainty increased with lower sampling frequency. The FDC method was able to decrease the uncertainty, but much still remained, especially when concentrations of the measured variable showed great variation. In such cases, sensor technology might be a feasible option for further reducing the uncertainty.

The natural resources conservation service (NRCS) curve number method is widely used to estimate runoff from rainfall events for four hydrological soil groups (A, B, C, and D). However, the NRCS soil groups do not yet include peat soils. Therefore, this study analyzed 59 rainfall-runoff events from two peat-dominated watersheds in Finland (Marjasuo, Royvansuo) and one in Norway (Grualia). The analysis used the United States Army Corps of Engineers Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS) to calibrate curve numbers and initial abstraction ratios (Ia/S). This gave a mean Ia/S of 0.036, with a mean standard error of 0.003 and 95% confidence interval of 0.030–0.042, which is significantly lower than the value of 0.2 recommended in the NRCS curve number method. The mean curve number was 61, with a mean standard error of 0.9 and 95% confidence interval of 59–63 for the study watersheds. This study confirmed that application of the NRCS curve number method in HEC-HMS required se...

Summary Content of 18O, 2H, 3H and geochemical components in rainfall, stream water, peat water and bedrock groundwater in four headwater catchments were compared to reveal differences in sources of runoff and hydrological vulnerability to tunnel drainage during summer. Water previously stored within the catchments was the predominant component of streamflow during small and moderate events. The proportion of event water increased at high discharge in autumn. Neither the isotopic nor the hydrochemical composition of stream water indicated any considerable contribution from old bedrock groundwater. Stream water hydrochemistry revealed clear influence of soil water pathways. The differences in land cover could be seen in water quality and runoff generation. Water storage and mixing in lakes and lowland wetlands reduced fluctuations in runoff and water quality. Runoff retention and the solute trapping effect in peatlands were most efficient in flat areas near the catchment outlet. In lowflow periods fluxes from hillslopes were of minor importance compared to discharges from wetland water storage. Water delivery from hillslopes with thin till cover (

The suitability of shell sand as a P sorbent has been tested both with laboratory batch experiments as well as in a sub-surface flow (SSF) meso-scale constructed sand filter treating municipal wastewater from a single household. The batch experiments suggest that retention of P in shell sand occurs both as sorption and precipitation. The soil–water ratio was found to be a crucial parameter when performing laboratory batch experiments. The maximum retention capacity was about 8000 and 800 mg P kg −1 sand, and the K d was 33.7 and 82.9 L kg −1 for soil–water ratios of 5 g–75 mL and 50 g–50 mL, respectively. The average total accumulated P concentration in samples from the SSF sand filter was 335 mg P kg −1 . The K d value based on [PO 4 3− ] and accumulated concentration of inorganic P in the SSF filter was 89.8 L kg −1 . Thus the batch experiments overestimated the retention capacity of shell sand in real sand filter systems, however, a ratio of 50–50 gave a more reasonable estimate than a ratio of 5–75. The K d value from batch samples with a ratio of 50–50 also gave a good estimate of the K d value in the constructed sand filter. Ca–P was found to be the predominant form of P mineral in samples collected from the SSF sand filter. Some Al–P, loosely bounded P, and occluded P were also present in the sand.

Laboratory incubations with varying O2 and NO3 concentrations were performed with a range of filter materials used in constructed wetlands (CWs). The study included material sampled from functioning CWs as well as raw materials subjected to laboratory pre-incubation. 15N-tracer techniques were used to assess the rates of denitrification versus dissimilatory nitrate reduction to ammonium (DNRA), and the relative role of nitrification versus denitrification in producing N2O. The N2O/(N2+N2O) product ratio was assessed for the different materials. Sand, shell sand, and peat sustained high rates of denitrification. Raw light-weight aggregates (LWA) had a very low rate, while in LWA sampled from a functioning CW, the rate was similar to the one found in the other materials. The N2O/(N2+N2O) ratio was very low for sand, shell sand and LWA from functioning CWs, but very high for raw LWA. The ratio was intermediate but variable for peat. The N2O produced by nitrification accounted for a significant percentage of the N2O accumulated during the incubation, but was dependent on the initial oxygen concentration. DNRA was significant only for shell sand taken from a functioning CW, suggesting that the establishment of active DNRA is a slower process than the establishment of a denitrifying flora.

Horizontal subsurface flow constructed wetlands have proven their efficiency in treating wastewater and removing the pollutants of concern. Treatment efficiency depends on the wastewater residence time, which is a function of the hydraulic loading and the physical conditions of the constructed filter system, which can be described with effective parameters such as: hydraulic conductivity, porosity, dispersivity etc. Because spatial variability is often scale dependent, these effective parameters may be affected by the scale of the system being studied. In this paper the results of tracer experiments in constructed filters using saturated horizontal flow at three scales (small and medium lab scales and full-scale system) using the same filter media is reported. Light-weight aggregate (filter media termed Filtralite-PTM) was used at all scales. Increasing the scale was associated with increasing dispersivity, meanwhile hydraulic conductivity experienced dramatic reduction and variation by increasing the examined scale. Observed changes in the hydraulic parameters indicate that heterogeneity at different scales should be taken into account when the performance of LWA filters are evaluated from small-scale experiments.

Corrigendum to “Long-term trends and variation of acidity, CODMn and colour in coastal rivers of Western Finland in relation to climate and hydrology” [Sci Total Environ 408/21 (2010) 5019–5027] Tuomas Saarinen⁎, Kari-Matti Vuori , Erkki Alasaarela , Bjorn Klove a Water Resources and Environmental Engineering Laboratory, Department of Process and Environmental Engineering, P.O. Box 4300, University of Oulu, FIN-90014 Oulu, Finland b Finnish Environment Institute, P.O. Box PL 35, FIN-40014 University of Jyvaskyla, Finland c Thule Institute, P.O. Box 7300, University of Oulu, FIN-90014 Finland

The European Groundwater Directive could be improved by limiting the scopes of the Annexes I and II to the manmade and natural substances, respectively, and by defining a common monitoring protocol. The changes in the European landuse patterns, in particular the urban sprawl phenomena, obscure the distinction between the point and diffuse sources of contamination. In the future more importance will be given to the household contamination. Moreover, the agricultural environment could be used for developing new conceptual models related to the pharmaceuticals.

Determination of metal risk levels in potable water and their effects on human health are vital in assessment of water resources. Risk assessment of metals to human health in a watershed, which has not been studied before, is the main objective of the present study. Surface and groundwater sampling was carried out between September 2010 and August 2011 in the Melen Watershed, Turkey, an important drinking water resource for millions of people. Metals were analyzed in the laboratory using inductively coupled plasma. Of the 26 different metals monitored, Al, B, Ba, Cr, Cu, Fe, Mn, Mo and V were found in surface water and As, B, Ba, Cr, Cu, Mn, Mo, V and Zn in groundwater. In groundwater, unitless hazard quotient (HQ) values were 6 for As, 2.7 for Mn and 1 for Zn, while in surface water all metals were below the risk level (HQ < 1). The ingestion risk was found to be higher than the dermal uptake risk. Arsenic mean concentration was observed to be 0.044mg/L in groundwater. The As carcinogenic risk (CR) value was higher than the internationally accepted risk level (10(-4)) and with maximum ingestion of groundwater the carcinogenic risk was found to be higher in adults than children. These results show that even unpolluted watersheds can pose a risk to human health and that potential carcinogenic impacts should receive more attention.

Runoff water quality from a peat mine was studied during 1995 and 1996 in Central Finland. Water samples from three drained sub-catchments and groundwater were analysed for all the standard physio-chemical parametres including different forms of nitrogen and phosphorus. The annual leaching of phosphorus, nitrogen and suspended solids was estimated to be 16–38 kg km−2, 1073–1500 kg km−2, and 2–8 t km−2, respectively. The variation in nutrient concentrations could be best explained by the relative volumes of new water (5-day sum of rainfall), ditchwater temperature and conductivity. Heavy rainfall caused new water to infiltrate washing nitrate out of the unsaturated peat layer resulting in high concentrations in ground- and ditchwater. Ditchwater phosphorus concentrations always decreased with increased runoff and peaked, as did COD and colour, after dry spells when old groundwater dominated runoff. A large part of the suspended solids load occurred during snowmelt, whereas dissolved solids and nitrogen loads peaked during summer flows.

The hydrology of a cutover fen was studied from May to October in 1995 and 1996. Rainfall equivalent depths were measured every 15 min and stream runoff was continuously monitored. Water table depths were measured bi-weekly during 1995 and continuously during 1996. Storm runoff was separated into different components; rain falling directly into channels and rapid groundwater response based on a contributing area method and on different electrical conductivities of rain-, ground- and streamwater. The results show three sources of storm runoff from cutover fens. Frequent small runoff peaks were caused by rain falling directly into channels. The amount of quick runoff increased when rain fell on wet soil, resulting in intermediate sized runoff peaks generated by rapid groundwater response. The largest runoff values were observed after prolonged rainfall when water from the upper part of the catchment flooded the fen. (C) 1999 Elsevier Science B.V. All rights reserved. (Less)

Major factors affecting sediment erosion from peat mines were assessed to provide information on the peat delivery mechanism. Surface runoff and erosion from three plots of 100 m 2 were measured in the field using three different rainfall intensities varying from 0.58–4.38 mm/min. The settling of peat was studied in the laboratory using a settling column. The settling of peat increased with the wetness of the peat. Within the range of the characteristics studied, water temperature and sediment concentration did not change the settling velocity. The erosion process exhibits three different time dependent stages. First, the sediment concentration decreases rapidly from the onset of runoff due to a decrease in erosion by rainfall as more water is added to the surface. During constant surface runoff and rainfall, the erosion decreases due to a decrease in rill development. When the precipitation ceases, the decrease is more pronounced. Ditch erosion is highest in ditches where there is floating peat or the bed material consists of mineral soils. Results obtained in this study suggests that efficient sediment control procedure includes runoff detention during the early stage of a runoff event and the continuous pounding of water above the erodible bed deposits.

Settling ponds are used to prevent erosion and the transport of suspended material from peat mines into downstream watercourses. In this study, three different sedimentation ponds were compared under laboratory conditions. The ponds were built on 1/10 and 1/20 scales. Two types of experiments were carried out. Hydraulic characteristics were determined using tracers and the flow‐through curve approach. The efficiency of removal was measured by the settling of peat during constant inflows. The results of settling experiments show that a circular vortex‐settling basin is superior in the reduction of suspended solids during high hydraulic loads; a rectangular basin favours settling during low flow. Because, during constant surface load, the settling efficiency decreases with increasing depth, due to increased turbulence, it is suggested that sufficient settling is achieved by shallow artificial floodplains.

[EN] Multi-criteria decision analysis (MCDA) methods are increasingly used to facilitate both rigorous analysis and stakeholder involvement in natural and water resource planning. Decision making in that context is often complex and multi-faceted with numerous trade-offs between social, environmental and economic impacts. However, practical applications of decision-support methods are often too technically oriented and hard to use, understand or interpret for all participants. The learning of articipants in these processes is seldom examined, even though successful deliberation depends on learning. This paper analyzes the potential of an interactive MCDA framework, the decision analysis interview (DAI) approach, for facilitating stakeholder involvement and learning in groundwater management. It evaluates the results of an MCDA process in assessing land-use management alternatives in a Finnish esker aquifer area where conflicting land uses affect the groundwater body and dependent ecosystems. In the assessment process, emphasis was placed on the interactive role of the MCDA tool in facilitating stakeholder participation and learning. The results confirmed that the structured decision analysis framework can foster learning and collaboration in a process where disputes and diverse interests are represented. Computer-aided interviews helped the participants to see how their preferences affected the desirability and ranking of alternatives. During the process, the participants knowledge and preferences evolved as they assess their initial knowledge with the help of fresh scientific information. The decision analysis process led to the opening of a dialogue, showing the overall picture of the problem context, and the critical issues for the further process., This study was funded by the GENESIS project (contract number 226536) under the EU’s 7th Framework Programme and the Academy of Finland (project number 128377).

High level expertise is increasingly important for the development in cold region countries. Doctoral degree is a clear advantage in international cooperation in business, consultancy, education and sciences. In Finland, nationwide systematic doctoral education was introduced in 1995 in a form of a graduate school system. The system aims to ensure high quality and systematic training for doctoral students with entry into working life within four years. By 2012 the expanded system consisted of 1600 funded 4year student positions in 112 graduate schools. Most of these graduate schools are based on nationwide or local cooperation between universities and research institutes. The doctoral training system in its present form will be terminated by the end of 2015, and each university will establish their own graduate school systems. This paper introduces the systematic Finnish doctoral education system and examines its future.

Transport of particulate pollutants in fluvial systems can contribute greatly to total loads. Understanding transport mechanics under different hydrological conditions is key in successful load estimation. This study analysed trace elements and physico-chemical parameters in time-integrated suspended sediment samples, together with dissolved and total concentrations of pollutants, along two agriculture- and peatland-dominated boreal river systems. The samples were taken in a spatially and temporally comprehensive sampling programme during the ice-free seasons of 2010 and 2011. The hydrochemistry and transport of particle-bound elements in the rivers were strongly linked to intense land use and acid sulphate soils in the catchment area, with arable, pasture and peat areas in particular being main diffuse sources. There were significant seasonal and temporal variations in dissolved and particulate fluxes, but spatial variations were small. Continuous measurements of EC, turbidity and discharge proved to be an accurate indicator of dissolved and particulate fluxes. Overall, the results show that transport of particle-bound elements makes a major contribution to total transport fluxes in agriculture-dominated boreal rivers. (C) 2013 Elsevier B.V. All rights reserved.

The authors investigate the sources and processes of groundwater contamination and their assessment within the Drivers-Pressures-State-Impact-Response (DPSIR) framework. Naturally occurring substances, trace elements, radionuclides, nutrients, and salt (sodium chloride) are reviewed with emphasis on the assessment of the natural background load. Some synthetic substances are also considered, these being petroleum hydrocarbons, chlorinated aliphatics, pesticides and organic-waste contaminants. Newly emerging contaminants cannot be described within the DPSIR; therefore monitoring approaches and indicators of contamination are discussed in order to propose improved monitoring plans that combine physical, chemical and biological indicators and combine science with policy.

Drainage of acid sulphate soils (ASS) increases oxidation, leading to extensive leaching of acidity and metals to rivers (Al, Cd, Cr, Fe, Ni and Zn). This is often apparent during high runoff periods in spring and autumn after long dry periods with low groundwater levels and associated ASS oxidation. Regression models were used to study changes in these water quality variables according to various discharge scenarios. The knowledge of seasonal patterns of water quality variables in future is important for planning land use of the catchments in relation to WFD of European Union. The data showed that river water acidity (pH and metals) increased with discharge, with the correlation being strongest in low runoff periods in winter and summer and less clear in spring. With future climate change, river acidity can increase radically, especially during winters following extremely dry summers, and pH and metal peaks may occur even during winter.

WOS:000295658500007 Groundwater dependent ecosystems (GDEs) include valuable ecosystems such as springs, wetlands, rivers, lakes and lagoons. The protection of these systems and services they provide is highlighted by international agreements, i.e. Ramsar convention on wetlands, and regional legislation, i.e. the European Water Framework Directive. Groundwater provides water, nutrients and a relatively stable temperature. However, the role of groundwater in surface ecosystems is not fully understood. The ecosystem can depend on groundwater directly or indirectly, and the reliance can be continuous, seasonal or occasional. This has implications for the vulnerability of ecosystems, as some may be easily affected by external pressure. Conceptual models and quantitative assessments of how groundwater interacts with the environment are needed. GDEs are also threatened by different land use activities and climate change. Hence, we need to understand how GDEs are affected by changes in groundwater quantity and quality, as severe groundwater changes have been observed in many regions. This study examines key aspects of GDEs (hydrogeology, geochemistry and biodiversity) in order to improve conceptual understanding of the role of groundwater in such ecosystems. The status and baseline of different types of GDEs are discussed, with particular emphasis on past evidence of environmental change and potential thresholds and threats in GDEs in various parts of Europe with different land use, climate and geology. (C) 2011 Elsevier Ltd. All rights reserved.

In drained peatland forests ditch networks need regular maintenance operations in order to sustain their drainage capacity. These operations however have a significant impact on the quality of the runoff water from the ditched areas. Peak runoff control (PRC) method has been proposed as a possible method to diminish the load to water courses through retention of the runoff temporarily in the ditch network during maximum runoff events using dams with a plastic control pipe. However, blocking water into the ditched area for periods of varying length during the growing season may have a negative impact on the growth of the tree stands. In this study past stand growth was investigated in Central Finland in altogether 10 sample Scots pine thinning stands in which the PRC method has been applied 5 growing seasons earlier. In each stand, a pair of sample plots was established: one plot next to the dam within the influence of periodic flooding and the other one outside the effect of periodic flooding. For determining stand growth, field measurements were made in August 2009. Stand growth near the dam was on average 0.54 m ha a lower than farther away from the dam but the analysis of covariance showed that the dam effect was not significant. The results of this study suggest that the PCR method does not decrease Scots pine stand growth during the first five year growth period after ditch cleaning.3-1-1

High acidity caused by geochemical processes and intensive land use of acid sulphate (AS) soils have continuously degraded the status of water bodies in Western Finland. Despite this, research on the long-term pattern and dynamics of acidification in rivers affected by acid sulphate soils is scarce. This study examined changes in alkalinity and pH value during the period 1913–2007 in nine large Finnish rivers discharging into the Gulf of Bothnia. In addition, patterns of COD Mn and colour were analysed during the period 1961–2007. Relationships between pH, alkalinity, COD Mn and colour and climate variables were also studied. In four rivers with no AS soil impact (Kokemaenjoki, Kemijoki, Iijoki and Oulujoki), critically low pH levels did not occur during the study period, whereas three rivers exposed to minor or moderate levels of runoff from AS soils (Lestijoki, Kalajoki, and Siikajoki) had all periods with critically low pH and alkalinity. The most severe acidity problems occurred in the rivers Kyronjoki and Lapuanjoki, with extensive drainage of AS soils being the main reason for the low pH status. Maximum discharge was clearly related to the acidity status of many rivers during the autumn–winter runoff period, when a significant negative linear correlation was found between maximum discharge and minimum pH in the rivers affected by AS soils. There was also a more distinct relationship between maximum chemical oxygen demand (COD Mn ) and minimum pH in autumn runoff than in spring. COD Mn levels significantly increased with increasing discharge in the rivers with no or minor AS soil impact. Climate change is predicted to increase river flow in general and winter discharge in particular, and therefore the acidity problems in affected rivers may increase in a future climate.

The Skjonhaug constructed wetland (CW) is a free surface water (FSW) wetland polishing chemically treated municipal wastewater in southeastern Norway and consists of three ponds as well as trickling, unsaturated filters with light weight aggregates (LWA). Fluxes of nitrous oxide (N(2)O) and methane (CH(4)) have been measured during the autumn, winter and summer from all three ponds as well as from the unsaturated filters. Physicochemical parameters of the water have been measured at the same localities. The large temporal and spatial variation of N(2)O fluxes was found to cover a range of -0.49 to 110 mg N(2)O-N m(-2) day(-1), while the fluxes of CH(4) was found to cover a range of -1.2 to 1900 mg m(-2) day(-1). Thus, both emission and consumption occurred. Regarding fluxes of N(2)O there was a significant difference between the summer, winter and autumn, with the highest emissions occurring during the autumn. The fluxes of CH(4) were, on the other hand, not significantly different with regard to seasons. Both the emissions of N(2)O and CH(4) were positively influenced by the amount of total organic carbon (TOC). The measured fluxes of N(2)O and CH(4) are in the same range as those reported from other CWs treating wastewater. There was an approximately equal contribution to the global warming potential from N(2)O and CH(4).

Hydraulics of subsurface flow filters (SSF) was studied by measurement of soil hydraulic conductivity (K) variation and performing tracer tests in two SSF filters consisting of 1-4 mm Ca rich sand (shell sand). Soil samples were carefully taken at several locations in Filter I. A tracer experiment was conducted in the undisturbed Filter II using KI. The measured K variability in Filer I was used to analyze the variations in tracer breakthrough. The spatially distribution of K was obtained by fitting a variogram to observed data and interpolation using Kriging. The tracer residence probability density function (PDF) was determined by modelling the tracer movement with a 3-D groundwater model. The observed and simulated tracer arrival was compared for cases with constant K, constant K and dispersion (D), and for spatially variable K and dispersion. The results show that groundwater models were well suited to simulate solute movement in the SSF system studied. An almost perfect fit to observed tracer PDF was obtained when variable K and dispersion was included in the model. This indicates that information on K variability and dispersion is important for studying solute movement in SSF constructed wetlands.

Aquifers are facing severe pressure from water extraction and irrigation. In many regions groundwater tables have declined considerably and aquifers have become polluted by various pollutants such as nitrates. The changes observed in groundwater quantity and quality are a threat (i) to the crucial ecosystems services groundwater provides such as drinking and irrigation water provision, natural attenuation processes, storage functions and habitats, as well as (ii) to groundwater dependent ecosystems such as springs, rivers, wetlands, and lakes. In order to provide sustainable solutions new methods are needed in groundwater management where groundwater systems are seen in a more holistic and integrated way. The impact-response ecosystem service models are a model class useful to show potential known or predicted changes, among those the European Commission adopted the DPSIR framework that defines the Drivers that by Pressures affect the water Status causing Impacts and Reponses. However the full application of the DPSIR requires the development of different conceptual models. The one related to biogeochemistry requires the identification of the sources and pathways of contamination and the biogeochemical processes that have influence on the transfer of the contaminants from the soil to the groundwater. Once the conceptual model is well developed, it is possible to use software tools for leaching assessment at different scales and it is possible to apply the impact response model assessing the impact of future scenarios considering climatic and land-use changes. The special issue reports paper that are investigating on the assessment of the pollutant input into groundwater systems and on the measures for protecting groundwater, considering also the assessment of the effect of climate and land-use change. Case studies are reported. The substances that are stated in the issue are trace metal, salt, nutrient, pesticide and organic waste water contaminants. The special issue includes mainly papers coming from GENESIS project (Groundwater and Dependent Ecosystems: New Scientific and Technological Basis for Assessing Climate Change and Land-use Impacts on Groundwater; EU project, contract number: 226536) and the issue addressed in the final conference on Integrated Management of Groundwater Resources and Dependent Ecosystems held in Prague from 5th to 7th March 2014.

Uncertainty is definitely one of the key topics in environmental assessment and management. Typically, attempts to reduce uncertainty are subject to expenses. But how to compare and trade-off expenses and the reduced uncertainty? They only seldom allow the use of a single unit. Instead, the whole analysis and decision procedure is very subjective. This paper presents one approach to handle such problems, namely the combined use of Bayesian influence diagrams, and probabilistic risk attitude analysis. The approach was used in the evaluation of three alternatives for a real time river water quality forecasting system. A trade-off analysis of risk attitudes, costs and uncertainty indicated the levels of socioeconomic utility required for investments in the respective systems, and accordingly illuminated the impact of the uncertainties involved on inference and decision-making with various risk attitudes and discount rates.

The hygienic quality of the water of the Kerava river, southern Finland, deteriorates occasionally. The purpose of the study was to design a real-time monitoring system that would inform the public using the river for recreational purposes about the changes in water quality. The system was constrained to consist of on-line sensing of water quality and quantity, and adjacent forecasting models. Four different system alternatives were analyzed and compared. The first alternative observes river flow in real-time; the second alternative also monitors water temperature, turbidity, pH, conductivity and dissolved oxygen. The data collected in this way are used to forecast Streptococcus and E. coli concentrations, using canonical correlation and regression analysis. The third configuration is a two-step procedure, where river flow is first predicted by an ARMAX model and the hygienic state is then based on the flow estimate, as in the first assemblage. The most expensive monitoring system, which at present is the least well-known, is to apply the Lidar system, where the hygienic status of the river quality is observed directly using laser technology, placing less emphasis on modeling. In this paper, the alternatives are formulated and a preliminary comparison is made, using the criteria of operational feasibility, prediction uncertainty, investment and maintenance costs, and suitability for in-situ monitoring.

DOI of original article: 10.1016/j.watres.2008.05.008. * Corresponding author. Tel.: þ358 8 553 4491; fax: þ358 8 553 4507. E-mail address: anna-kaisa.ronkanen@oulu.fi (A.-K. Ronkanen). 0043-1354/$ – see front matter a 2008 Elsevier Ltd. All rights reserved doi:10.1016/j.watres.2008.08.017 Minus signs are missing in front of values 15.25, 11.45, 11.17, 10.04, 13.66 and 10.79 in the chapter 3.2. Isotope distributions: ‘‘The measured d values related to VSMOW standard varied from 15.25 to 11.45& in the Kompsasuo wetland, from 11.17 to 10.04& in the Puutiosuo wetland and from 13.66 to 10.79& in the Mellanaava wetland’’. The authors apologize for the error.