Search

A key question in environmental flow (EF) allocation from reservoirs is the annual distribution of flow. Flow release from reservoirs can be partly supplemented or compensated for by natural runoff from the downstream (residual) part of the catchment. Here we present a new hydrological approach to estimate the optimal intra-annual flow regime for EF which also considers water inflow from the downstream residual sub-catchment. First, the standard intra-annual regimes at downstream target points are defined for reference. This annual hydrograph is then divided into two main parts: a variable hydrograph (related to upstream of the reservoir and the point of EF release) and a residual hydrograph (associated with downstream catchment runoff). Based on the magnitude of the residual hydrograph, the allocated EF is estimated by optimization. This method provides a first estimate of the intra-annual EF regime based on hydrological data, but biological, geomorphological, and other effective components can also be included in the optimization procedure. To test the method, the intra-annual EF regime was estimated for four different points of the Kor river in southern Iran. The results showed that the best fit between the EF regime and the natural river regime at the reference point depended on the magnitude of allocated flow and the allocation site in the catchment.

Atmospheric circulation generally influences regional climate variability and thereby controls catchment hydrology and consequently transport of elements in natural riverine systems. This study examined dependencies between total organic carbon (TOC) variability in the River Oulujoki (Finland) during 1963–2011 and prominent atmospheric circulation patterns (ACPs), which manifest natural climatic conditions over Finland and control hydrological processes in the river catchment. North Atlantic Oscillation, Scandinavia, East Atlantic and East Atlantic/West Russia patterns were statistically significant ACPs affecting variations in TOC export at River Oulujoki lower basin area. In the River Oulujoki, TOC export was largely controlled by changes in TOC fluxes generated from tributaries of river and near areas to its main channel. Besides, runoff from Lake Oulujarvi slightly influenced TOC export variability in the River Oulujoki. Understanding such responses of TOC fluxes to ACPs is a useful tool for sustainable water resources planning and management on regional and local scales.

In the Boreal region, anticline eskers aquifers are recharged in upland hillslopes and water discharges in the surrounding lowlands. Organic peat soils often confine the aquifer discharge area and drainage of these confining peat layers can decrease the flow resistance in the peat soil, which may cause unintentional groundwater level drawdown. This poses a risk to groundwater bodies and their good water status in the Boreal region. To increase awareness of the risk areas and to assess potential areas for drainage restoration, a model based on geographical information systems (GIS) was developed to predict the locations of high groundwater discharge. The output of the model is a map highlighting the potential areas where groundwater is more likely to discharge. The model output was validated with stream flow data collected from two eskers located in Finland. The developed GIS model is recommended as a tool to delineate groundwater protection areas where drainage of the peat soil should not be allowed and for assessing areas where such drainage networks could be restored to protect vulnerable groundwater systems.

Peat extraction runoff water requires chemical treatment to remove organic matter and phosphorus. In Finland, ferric sulphate (FS) is normally used as coagulant agent, but significant variations in runoff water quality and the lack of optimisation of process parameters has led to increased acidity, metal and sulphate concentrations in the purified water. The use of synthetic organic polymers as an alternative to the commonly applied metal salt coagulant is suggested to better cope with typical variations in runoff water quality. This study evaluated the suitability of two synthetic organic polymers (polyDADMAC and polyAmine) for the purification of humic and sediment-rich diffuse runoff by comparing their performance to the normally applied iron-based coagulant. FS was found to require up to fourfold higher dosages but achieved higher overall purification levels than the organic polymers. In particular, removal of organic matter was substantially higher when FS was used. Of the two synthetic organ...

A combination of driving forces are increasing pressure on local, national, and regional water supplies needed for irrigation, energy production, industrial uses, domestic purposes, and the environment. In many parts of Europe groundwater quantity, and in particular quality, have come under sever degradation and water levels have decreased resulting in negative environmental impacts. Rapid improvements in the economy of the eastern European block of countries and uncertainties with regard to freshwater availability create challenges for water managers. At the same time, climate change adds a new level of uncertainty with regard to freshwater supplies. In this research we build and calibrate an integrated hydrological model of Europe using the Soil and Water Assessment Tool (SWAT) program. Different components of water resources are simulated and crop yield and water quality are considered at the Hydrological Response Unit (HRU) level. The water resources are quantified at subbasin level with monthly time intervals. Leaching of nitrate into groundwater is also simulated at a finer spatial level (HRU). The use of large-scale, high-resolution water resources models enables consistent and comprehensive examination of integrated system behavior through physically-based, data-driven simulation. In this article we discuss issues with data availability, calibration of large-scale distributed models, and outline procedures for model calibration and uncertainty analysis. The calibrated model and results provide information support to the European Water Framework Directive and lay the basis for further assessment of the impact of climate change on water availability and quality. The approach and methods developed are general and can be applied to any large region around the world., Journal of Hydrology, 524, ISSN:0022-1694, ISSN:1879-2707

Numerous studies have reported significant declines in snow resources in Finland and elsewhere during the 20th century. To identify the main climate factors controlling these declines in Finland, this study evaluated long-term variations and trends in wintertime climate, snowpack hydrological processes (SHPs) and continuous snow cover duration (CSCD), and their links to atmospheric circulation patterns (ACPs). Analyses were conducted using observed daily climatological time series and simulated SHPs at three stations in southern (Kaisaniemi), central (Kajaani) and northern (Sodankyla) Finland with about 100 years of data. The Mann-Kendall nonparametric test was used to detect significant trends, the Pearson's coefficient (r) to identify relationships within snow-related variables, and Spearman's coefficient (ρ) to measure correlations of these variables with ACPs. Sensitivity of the snow-related variables with projected changes in temperature and precipitation was assessed. The results showed increases in wintertime temperature only at Kaisaniemi, but decreases in wintertime precipitation, snowfall and snow water equivalent (SWE) and shorter CSCD at all stations. In general, variations in wintertime temperature were positively associated with the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO). However, wintertime precipitation showed significant relationships with the East Atlantic/West Russia (EA/WR), AO and West Pacific (WP) patterns in southern, central and northern Finland, respectively. SHPs and CSCD in southern Finland were associated with the same ACP influencing wintertime temperature (AO), and those in central and northern areas with the patterns influencing wintertime precipitation (EA, EA/WR and AO). Thus, declines in snow resources in Finland are mainly the result of reductions in snowfall owing to both wintertime warming and decreased precipitation at Kaisaniemi, while only to decreases in wintertime precipitation at Kajaani and Sodankyla stations. However, increase in precipitation (up to 30%) plays an important role in offsetting effects of temperature warming (up to 4 °C) on snow resource decline in Finland.

Using daily mean temperature datasets applied at regular grid points (10 × 10 km2) throughout Finland for the period 1961–2011, interannual variations and trends in thermal growing season (GS) parameters, in terms of start (GSS), end (GSE) and length (GSL) and their relationships with various atmospheric teleconnection patterns (ATPs) were analysed. The GSL in Finland naturally increases from north to south, in association with earlier GSS and later GSE. However, the results showed that during the last 50 years, GSL on national scale in Finland significantly (p

Chemical treatment of non-point derived pollution often suffers from undesirable oscillations in purification efficiency due to variations in runoff water quality. This study examined the response of the chemical purification process to variations in water quality using a 2(k) factorial design for runoff water rich in humic substances. The four k factors evaluated and the levels applied were: organic matter as dissolved organic carbon (DOC) (20-70 mg/L), suspended solids (SS) (10-60 mg/L), initial water pH (4.5-7), and applied coagulant dosage (ferric sulphate) (35-100 mg/L). Indicators of purification efficiency were residual concentration of DOC, SS and total phosphorus (tot-P). Analysis of variance and factor effect calculations showed that the initial DOC concentration in raw water samples and its interactions with the coagulant dosage applied exerted the most significant influence on the chemical purification process, substantially affecting the residual concentration of DOC, SS and tot-P. The variations applied to the factors SS and pH only slightly affected purification efficiency. The results can be used in the design of purification systems with high organic matter load variation, e.g. peat extraction runoff.

Summary Water resources management is moving towards integration, where groundwater (GW), surface water (SW) and related aquatic ecosystems are considered one management unit. Because of this paradigm shift, more information and new tools are needed to understand the ecologically relevant fluxes (water, heat, solutes) at the GW–SW interface. This study estimated the magnitude, temporal variability and spatial distribution of water fluxes at the GW–SW interface using a fully integrated hydrological modelling code (HydroGeoSphere). The model domain comprised a hydrologically complex esker aquifer in Northern Finland with interconnected lakes, streams and wetlands. The model was calibrated in steady state for soil hydraulic conductivity and anisotropy and it reproduced the hydraulic head and stream baseflow distribution throughout the aquifer in both transient and steady state modes. In a novel analysis, model outputs were compared with the locations and magnitude of GW discharge to lakes estimated using field techniques. Spatial occurrence of GW–lake interaction was interpreted from airborne thermal infrared imaging. The observed GW inflow locations coincided well with model nodes showing positive exchange flux between surface and subsurface domains. Order of magnitude of simulated GW inflow to lakes showed good agreement with flux values calculated with a stable water isotope technique. Finally, time series of GW inflow, extracted as model output, showed moderate annual variability and demonstrated different interannual inflow changes in seepage and drainage lakes of the aquifer. Overall, this study demonstrated the ability of a fully integrated numerical model to reproduce observed GW–SW exchange processes in a complex unconfined aquifer system. The model-based estimates obtained for GW influx magnitude and spatial distribution, along with information on GW quality can be used to estimate ecologically relevant fluxes in future water resources management.

Lake water level regimes are influenced by climate, hydrology and land use. Intensive land use has led to a decline in lake levels in many regions, with direct impacts on lake hydrology, ecology and ecosystem services. This study examined the role of climate and river flow regime in controlling lake regimes using three different lakes with different hydraulic characteristics (volume-inflow ratio, CIR). The regime changes in the lakes were determined for five different river inflows and five different climate patterns (hot-arid, tropical, moderate, cold-arid, cold-wet), giving 75 different combinations of governing factors in lake hydrology. The input data were scaled to unify them for lake comparisons. By considering the historical lake volume fluctuations, the duration (number of months) of lake volume in different ‘wetness’ regimes from ‘dry’ to ‘wet’ was used to develop a new index for lake regime characterisation, ‘Degree of Lake Wetness’ (DLW). DLW is presented as two indices: DLW1, providing a measure of lake filling percentage based on observed values and lake geometry, and DLW2, providing an index for lake regimes based on historical fluctuation patterns. These indices were used to classify lake types based on their historical time series for variable climate and river inflow. The lake response time to changes in hydrology or climate was evaluated. Both DLW1 and DLW2 were sensitive to climate and hydrological changes. The results showed that lake level in high CIR systems depends on climate, whereas in systems with low CIR it depends more on river regime.

Ditch network maintenance in drained peatland forests increases sediment load and causes harmful effects on downstream watercourses. The objective of this study was to identify the immediate erosion processes in the ditch network and quantify the impact of the ditch network maintenance on suspended solids (SS) load at the catchment outlet. Ditch level processes were measured by conducting field campaigns and catchment-level responses were obtained by using the paired catchment approach. Measurements were conducted at two nested catchments in Koivupuro, Eastern Finland, where runoff and turbidity were monitored continuously at the catchment outlets and erosion and deposition were measured in selected ditches with a pin meter, erosion pins and sediment collectors. According to the results, the sediment load was at its highest during the first year after the ditch network maintenance and especially high during the first spring snow-melt period. Pin-meter measurements, sediment-collector data and results of ditch-bed erosion pins showed that the erosion was more severe in the ditch cut into mineral subsoil than in the ditch cut into thick peat. The SS load from the whole Koivupuro catchment during the first year after the ditch network maintenance was, depending on the estimation method, 185 or 250 kg treated-ha −1 a −1 (0.56 or 0.75 kg ditch-m −1 ), while the net erosion within the ditch network was much higher, 6300 kg treated-ha −1 a −1 (19 kg ditch-m −1 ), indicating that suspended solids were deposited before reaching the outlet of the catchment. Compared to the earlier studies which have focused on the catchment-level effects of ditch network maintenance on the SS loads, the current study succeeded in showing erosion processes and their variability within the ditch network and provided information for improving water protection during ditch network maintenance.

The number of metal mines, the amount of ore processed, and thus the amount of mine wastewaters have been rapidly increasing in recent decades. Pretreated process effluent and drainage waters containing high concentrations of e.g., arsenic (As), antimony (Sb), and nickel (Ni) have been purified for up to 6 years in treatment peatlands at a gold mine in Finnish Lappland prior to their release into downstream water bodies. Retention efficiencies based on monitoring of peatland inflow and outflow waters indicated that retention of As, Sb, and Ni was generally good (up to 95%) but temporarily variable. Other contaminants such as sulfate or iron were retained less efficiently or were even leaching from the peatland. Most of the As, Sb, and Ni was retained close to the wastewater distribution ditch, and there was a near-linear increase in As, Sb, and Ni concentrations in the peatlands over time. Adsorption experiments indicated the high potential of peat soils to adsorb As, Ni and especially Sb. Accumulation of contaminants has led to or will lead to concentrations exceeding higher guideline values for contaminated soils within the next 1–18 years, which indicates a limited lifetime for treatment peatlands. Leaching of contaminants is anticipated in situations where clean natural waters mix with mine waters, e.g., during snowmelt or after mine closure, and desorption experiments suggest that especially easily mobilized (i.e., loosely-bound) fractions of As, Sb, and Ni are likely to leach from the treatment peatlands. The collective data indicate (i) high purification efficiencies for As, Sb, and Ni in the peatlands, (ii) high adsorptive capacity of the peat soil for those contaminants, (iii) increased risk of contaminant leaching e.g., after mine closure, and (iv) a need for further studies of environmental parameters and retention processes affecting contaminant removal efficiencies and potential lifetimes of treatment peatlands.

Treatment wetlands are considered best management practice as they can remove nitrogen, phosphorus and suspended solids from peat extraction or forestry runoff. Treatment wetlands are established on intact or formerly drained peatlands after restoration of the site hydrology by ditch blocking or other methods. However, drainage changes the physical properties of peat, so the hydraulic and hydrological conditions in peatlands may change. Consequently, treatment wetlands constructed on drained areas may have short residence times, resulting in poor purification results. This study determined the hydrological and hydraulic characteristics of treatment wetlands constructed on drained peatlands by studying peat hydraulic conductivity and water distribution in 20 different wetlands in Finland. Four wetlands were studied in more detail using tracer tests, water balance and continuous groundwater measurements. More than 50% of the drained treatment wetlands studied had a lower active flow depth layer (only 10 or 20 cm) with higher hydraulic conductivity ( K ) than normally found in pristine peatlands. At 25% of the sites, K was high at all depths investigated (down to 60–70 cm). At several sites, the water was unequally distributed across the wetland surface, indicating that only part of the wetland was being used for purification. The residence time, as determined by tracer tests, varied significantly between sites. These results indicate that past drainage still influences the hydraulics of treatment wetlands.

The main aim of this paper is to analyze the characteristics of the drinking water quality in Kabul city and identify its suitability for drinking. During the work, a total of 60 water samples were collected from four drinking water sources (qanat, open well, tap water, and a hand pump) located at different points and were tested for physical, chemical, and biological parameters. Physical and chemical analyses were performed according to the standard methods, while a bacterial analysis was performed by using the Wagtech Potatest single incubator test kit and membrane filter method. The results obtained were compared with the standards of the World Health Organization (WHO) and Afghanistan’s National Standards Administration (ANSA). The study showed that physical parameters were within acceptable limits for qanat, open well, and tap waters. However, color, taste, odor, and turbidity values exceeded the recommended limits for hand pump wells. All analyzed chemical parameters were within permissible limits recommended by WHO/ANSA. The bacteriological analysis showed total coliform and fecal coliform contamination, particularly in warm weather conditions. The bacteriological contamination reveals the mixing of the sewage water with drinking water due to expired corroded pipes and discharge of wastewater to the groundwater. Several governance recommendations are proposed for improving water quality. They include strengthening coordination between government and public, considering options to install a new water distribution and sewage collection networks, enforcing standards for adequately preventing contamination from septic tanks, and increasing public awareness on low-cost measures such as boiling the drinking water before intake.

Interest in climate change effects on groundwater has increased dramatically during the last decade. The mechanisms of climate-related groundwater depletion have been thoroughly reviewed, but the influence of global warming on groundwater-dependent ecosystems (GDEs) remains poorly known. Here we report long-term water temperature trends in 66 northern European cold-water springs. A vast majority of the springs (82%) exhibited a significant increase in water temperature during 1968-2012. Mean spring water temperatures were closely related to regional air temperature and global radiative forcing of the corresponding year. Based on three alternative climate scenarios representing low (RCP2.6), intermediate (RCP6) and high-emission scenarios (RCP8.5), we estimate that increase in mean spring water temperature in the region is likely to range from 0.67 °C (RCP2.6) to 5.94 °C (RCP8.5) by 2086. According to the worst-case scenario, water temperature of these originally cold-water ecosystems (regional mean in the late 1970s: 4.7 °C) may exceed 12 °C by the end of this century. We used bryophyte and macroinvertebrate species data from Finnish springs and spring-fed streams to assess ecological impacts of the predicted warming. An increase in spring water temperature by several degrees will likely have substantial biodiversity impacts, causing regional extinction of native, cold-stenothermal spring specialists, whereas species diversity of headwater generalists is likely to increase. Even a slight (by 1 °C) increase in water temperature may eliminate endemic spring species, thus altering bryophyte and macroinvertebrate assemblages of spring-fed streams. Climate change-induced warming of northern regions may thus alter species composition of the spring biota and cause regional homogenization of biodiversity in headwater ecosystems.

A new precipitation index-based model, which includes a snow accumulation and melt component, has been developed to simulate hydrology in high latitude catchments. The model couples a point snowmelt model with a current precipitation index (CPI) formulation to simulate continuous daily runoff from catchments with seasonal snow cover. A new runoff conversion factor: CT and Lf, threshold flow factor ThQ and runoff transformation function Maxbas were introduced into the CPI equation, which converts and transforms the routed daily CPI into daily runoff and maintains the daily base flow in the catchment. The model was developed using twelve sub-arctic boreal catchments located above and below the Arctic Circle in northern Finland, representing a region with considerable seasonal snow cover. The results showed that the model can adequately simulate and produce the dynamics of daily runoff from catchments where the underlying physical conditions are not known. An open-access Excel-based model is provided with this paper for daily runoff simulations. The model can be used to estimate runoff in sub-arctic regions where little data is typically available but significant changes in climate are expected, with considerable shifts in the amount and timing of snowmelt and runoff.

Effective groundwater monitoring and status assessment is vital in the management and protection of groundwater systems according to e.g., the European Groundwater Directive. This study determined metal concentrations in groundwater in the Melen watershed close to Istanbul and assessed land use effects on groundwater status. In the monitoring period (2010–2011), elevated metal concentrations were observed in regions close to industrial zones and seasonally in agricultural fields. The highest values of metals (As, Mn, Zn, V, Cu, Na and Ba) concentrations were found in autumn and winter, when groundwater recharge occurs. Detectable levels of dissolved metals, such as Cr and Cd, were only found close to industrial zones. The aquifer can be considered to be in good qualitative status regarding some metals. However, As, Mn and Zn are present in concentrations higher than approved by international standards and pose a risk to human health. Therefore, measures to prevent metal contamination close to potential sources and good watershed management are needed.

Annual and seasonal variations in surface air temperature (SAT) during the period 1961–2011 were analysed using daily mean temperature data sets from regular grid points (10 × 10 km2) throughout Finland. The Mann–Kendall nonparametric test was used to detect significant historical trends in SAT and Spearman's correlation coefficient (ρ) to test the relationships between SAT patterns and various atmospheric circulation patterns over the northern hemisphere. The results showed that mean annual SAT in Finland increased (p

Construction of dams affects river flow regimes and changes downstream ecosystems in many ways. The impacts of dams depend on local climate, dam purpose and operation policy. This study analysed the impacts of dam construction on river flow regimes and developed a new method to evaluate the effects on river flow. By using three main flow characteristics of river regime (magnitude, timing and intra-annual alteration), a new combined river impact (RI) index to assess construction impacts based on monthly flow data was developed. A preliminary evaluation of the method was made using the river Ebro as a case. A classification was developed where the impact was assessed using a scale from low to drastic. The method was further tested to quantify the effect of dams in 15 rivers located in different regions. The method showed good potential to classify different dam types of variable sizes constructed for different purposes. The RI index method also proved suitable for assessing the environmental impacts of dam construction and could be extended by adding other characteristics of flow regime to evaluate the effects of climate change or changes in land use on river flow regimes.

Interannual variability in meteorological dryness and wetness in central Finland during the period 1959–2009 was analysed using Standardized Precipitation Index (SPI) on three timescales (annual, seasonal and monthly). For different time steps (12, 3 and 1 months) of SPI values (SPI12, SPI3 and SPI1), trends based on the Mann-Kendall non-parametric test and the most significant relationships with a number of climate teleconnection patterns based on Spearman correlation coefficient (rho) were determined. Analysis of the SPI values on different timescales showed a general decreasing trend in dryness and an increasing trend in wetness; only August showed an increasing trend in dryness. The longest wet period observed was 5 years (between 1988 and 1992), while the longest dry period was 4 years (in the mid-1960s). Wet conditions were more frequent than dry conditions and mainly occurred at extreme or moderate level. Typically, the extremely wet level was more frequent than the extremely dry level. The dry and wet conditions were negatively correlated with the East Atlantic/West Russia and Scandinavia teleconnection patterns and positively correlated with the North Atlantic Oscillation.

Peat extraction for energy purposes causes major changes in the aquatic and terrestrial environment. According to national strategies for extracting peat in Finland, new peat extraction areas should be established on previously drained peatlands. On such areas it is difficult to find the natural, intact peatland required for treatment wetlands or so-called overland flow areas, which are considered the best available technology for runoff water purification. Therefore treatment wetlands must be constructed on drained peatland. It is known that drainage causes physical, biogeochemical and hydraulic changes in the peat layer, as well as changes in vegetation. It is probable that these changes affect the purification efficiency of wetland treatment systems in many ways. This study evaluated the function and characteristics of drained peatland areas for purification of peat extraction runoff water. Study sites were established on 11 drained wetlands and their purification efficiency was evaluated. Detailed measurements of peat physical properties and hydraulic conductivity, as well as studies on vegetation, were also made in the study areas. The results showed that wetlands constructed on drained peatland areas can purify peat extraction runoff. However, leaching of phosphorus (P) and iron (Fe) was observed in some areas. Leaching is influenced e.g. by pH and the soil P pool. The chemical oxygen demand was also observed to increase in runoff water from the wetland. The results indicated that low (Fe + aluminium (Al) + manganese (Mn))/P ratio (≤ 25) and quite high P content (> 1200 mg/kg) in the surface peat characterised those areas where P leaching was observed. The presence of a dense tree stand in a drained peatland area also seemed to indicate release of nutrients from the area after its rewetting and use as a treatment wetland. Thus, potential nutrient release from a drained peatland area intended for use as a treatment wetland can be assessed by studying the characteristics of the peatland area, especially the peat mineral content, and the vegetation, especially tree stand density in the area. Using the findings obtained, a conceptual decision tree was drawn up in order to help to establish and design wetlands in previously drained peatland areas.

Groundwater dependent ecosystems (GDEs) include many terrestrial and aquatic systems with high biodiversity and important ecosystem services. The need for protection of these systems has recently received increasing recognition in many regions, including the European Union (EU), as pressures on groundwater are increasing due to increased consumption in agriculture and intensive land use. A key issue is to provide legislative frameworks that safeguard the ecosystem services these systems provide. This paper reviews European legislation and present methods for theoretical frameworks, and hydrological and ecological observations of GDEs. Insights into the current state of research are provided and gaps in scientific knowledge identified. Different restoration and protection measures, such as buffer zones, are presented and evaluated. Recommendations are given for the future protection of GDEs. Future research should focus on nationally important GDE sites to establish conceptual models describing the individual and interactive impacts of multiple stressors on the hydrological and ecological functioning of GDEs. Proactive management is required to protect GDEs from contamination, for example by using extended buffer zones and careful land use planning in the groundwater capture zone.

Properties of suspended particulate matter play a vital role in transport processes, but information from boreal lowland river systems with high organic loads is limited. This study analysed data from 2 years of sampling at 30 locations in Finland (204 samples in total) using suspended particulate matter samplers to determine effective and absolute particle size and organic fractions. Mean d50 value was 22 and 49 µm for absolute and effective particle size, respectively. The organic fraction content ranged from 2.1% to 36% (mean 9.6%), highlighting the importance of particle organic matter for suspended particulate matter flux in the region. The results indicated that the suspended particulate matter particle size distribution and load in the study region is dominated by composite particles. There were considerable spatial and temporal variations in transport of organic fractions, effective particle size and degree of aggregation (range 1.5–93%). Headwaters and, in particular, late summer and spring flood conditions with flow peaks produced the largest composite particles, whereas agriculture-dominated sites produced smaller but more tightly compacted particles. Organic plant fibres appeared to play a vital role in floc formation in peat-covered catchments, whereas in agriculture-dominated catchments, land use-derived aggregates dominated the composition. This study provides empirical evidence of the importance of effective particle size measurement in understanding the dynamics of suspended particulate matters in boreal lowland river systems. Copyright © 2014 John Wiley & Sons, Ltd.

Erosion from peat extraction areas is known to cause siltation of water courses and poor water quality. However, the main soil parameters affecting peat erosion and suspended sediment (SS) yields from different catchments are not well understood. This paper used peat properties (degree of humification, peat type, ash content, porosity, moisture content, bulk density, and shear strength) and novel erosion threshold measurements from intact soil cores to explain peat erodibility and spatial variations in SS concentrations (SSCs) and SS loads (SSLs) at 20 Finnish peat extraction sites. The erosion threshold measurements suggested that critical shear stresses for particle entrainment decrease with increasing degree of humification (von Post scale) and are significantly lower in well-decomposed peat than in slightly or moderately decomposed peat. Two critical shear stresses were obtained from moderately decomposed peat samples, indicating a degree of surface armoring by coarse peat fibers. Monitored long-term average SSC was highest at study sites with well-decomposed peat, while very fine-grained mineral subsoil explained some of the highest long-term SSC in areas where drainage ditches penetrated below the upper peat layer. Average SSL (kg d−1) at the study sites was best explained (R2 = 0.89) by average discharge and surface peat decomposition level. Overall, this study provides new knowledge on peat erosion and critical shear stresses that can be used in water conservation and sediment management practices for cutover peatlands and other similar land uses.

Esker aquifers are common groundwater bodies in Europe. Management of these aquifers should take account of the sustainability of groundwater-dependent ecosystems and land use in an integrated way. An unconfined esker aquifer in northern Finland was modelled with MODFLOW to determine how groundwater resources are impacted by the surrounding peatland drainage scheme and to simulate scenarios for possible drainage restoration. The impacts of groundwater abstraction and climate change were also simulated. A calibration-constrained Monte Carlo method was used to provide information on the uncertainties associated with model predictions. The results suggest that peatland drainage in the vicinity of eskers can have a significant role in lowering the water table, even though climate variability may mask these impacts. Drainage restoration by filling the ditches might have positive impacts on the aquifer water levels. Comparison of water-table changes caused by peatland drainage with the changes brought by water abstraction and climate variability helped to quantify impacts of different land-use scenarios and facilitated discussion with the local stakeholders. Based on this study, more attention should be devoted to peatland drainage schemes in integrated groundwater management of esker aquifers.

Annual, seasonal and monthly variations in precipitation during the period 1911–2011 were evaluated using spatially interpolated monthly precipitation records at 165 stations with more than 30 years of data (of which 32 stations had 101 years of data referring to full length of study period). Historical trends and cyclic patterns of precipitation and links to teleconnection indices were analysed. The results show that annual precipitation in Finland increased by 0.92 ± 0.50 mm year−1 (p 0.05). Winter precipitation was most strongly correlated with the North Atlantic Oscillation (NAO) index (ρ = 0.55, p

Highlights • Investigate the impact of instant energy demand on sub-daily river regime. • Introducing power market impact index. • Introducing system efficiency ratio index. • Provides an efficient tool for sustainable river management. • Assess the interaction of power market and regulation practices. With increasing power production from renewable energy sources, sub-daily variations in energy demand need to be balanced. Today, hydropower is commonly used as balancing power. In this study, we quantified the impact of capacity constraints, in terms of reservoir volume and hydropower capacity, on the potential to comply with instant energy demand. To evaluate the impact, we developed two new metrics, power market impact and system efficiency ratio, which are based on two threshold flow regimes derived from natural flow as lower threshold release and regulated flow (based on hourly energy prices) as upper threshold release. The operation support model comprises 96 different regulation scenarios based on varying combinations of hydropower and reservoir capacities. For each scenario, an hourly water balance was simulated, to obtain the highest complying with upper threshold release based on actual energy demand. We tested the framework on the Kemijoki river with defined thresholds based on the natural flow regime (tributary river Ounasjoki) and the hourly energy price in Finland in 2017, and estimated the impact of regulation on hourly flow regime at the Taivalkoski hydropower station. The annual flow regime impact in 2013, 2014 and 2015 was estimated to be 74%, 84% and 61%, respectively, while the monthly impact varied from 27% to 100%. Our framework for evaluating interactions between the power market and sub-daily regulation practices is a useful novel tool for sustainable river management and can be easily applied to different rivers and regions and evaluated for different timescales.

Ecosystem protection requires a better definition of groundwater (GW) dependence and tools to measure this dependence. In this study, a classification method for the GW dependence of headwater streams was devised based on the fact that GW affects discharge, thermal regime, and water quality. The method was tested in three boreal headwater streams discharging from two esker aquifers. Spatial and temporal variability of GW dependence were studied in the stream continuum at several locations, by combining continuous measurements of temperature, electrical conductivity, and discharge with discrete sampling of environmental tracers (e.g., stable water isotopes, silica, chloride). The stream tracer index method developed was used to classify stream sections into GW-dominated, GW-surface water (SW) transition, and SW-dominated zones. We found that, spatially, GW dependence along the stream varied widely, with calculated stream tracer index values ranging from 33 to 94%. The GW-dominated areas extended at least 745, 1 682, and 4 202 m downstream from the main GW discharge points in the three streams studied. A stream located in a pristine peatland-dominated catchment was more prone to rapid change from GW- to SW-dominated than two streams located in catchments dominated by peatland forestry. These results suggest that to evaluate the GW dependence of streams, it may be sufficient to sample stream sections only once, during summer low-flow conditions. The proposed method can serve as a water management tool, especially for streams of exceptional ecological importance or in places where anthropogenic activities are expected to change local hydrology and ecology.

Climate change’s effect on sea surface temperature (SST) at the regional scale vary due to driving forces that include potential changes in ocean circulation and internal climate variability, ice cover, thermal stability, and ocean mixing layer depth. For a better understanding of future effects, it is important to analyze historical changes in SST at regional scales and test prediction techniques. In this study, the variation in SST across the Persian Gulf and Gulf of Oman (PG&GO) during the past four decades was analyzed and predicted to the end of 21st century using a proper orthogonal decomposition (POD) model. As input, daily optimum interpolation SST anomaly (DOISSTA) data, available from the National Oceanic and Atmospheric Administration of the United States, were used. Descriptive analyses and POD results demonstrated a gradually increasing trend in DOISSTA in the PG&GO over the past four decades. The spatial distribution of DOISSTA indicated: (1) that shallow parts of the Persian Gulf have experienced minimum and maximum values of DOISSTA and (2) high variability in DOISSTA in shallow parts of the Persian Gulf, including some parts of southern and northwestern coasts. Prediction of future SST using the POD model revealed the highest warming during summer in the entire PG&GO by 2100 and the lowest warming during fall and winter in the Persian Gulf and Gulf of Oman, respectively. The model indicated that monthly SST in the Persian Gulf may increase by up to 4.3 °C in August by the turn of the century. Similarly, mean annual changes in SST across the PG&GO may increase by about 2.2 °C by 2100.

The aim of this study is to compare empirical (pseudo first-order, pseudo second-order, and Elovich models) and theoretical models (second order chemical reaction rate, film diffusion, and particle diffusion models) in the modeling of nitrate uptake by ion exchange resin. The modeling showed that the pseudo first and second order models describe the experimental kinetic data satisfactorily; however, the estimated rate constants varied significantly with the experimental conditions. In comparison with empirical models, theoretical models describe the experimental data with higher precision. In addition, the relative differences between the computed constants of each theoretical model are much less than the estimations of empirical models. The estimated constants of film diffusion model and particle diffusion model for different sets of experimental data were close to the average values, confirming that these models are indeed superior when it comes to the description of the kinetics of nitrate removal. Finally, the performance of ion-exchange column was evaluated using the particle diffusion model in conjunction with mass balance equation in column, with the results of the model predictions being compared to the experimental breakthrough curves. The selected mathematical equations reproduced the experimental breakthrough data very well.

Summary Different indices have been developed to classify rivers and assess land use and climate change impacts on rivers. These methods are not universal, but tend to depend on local conditions such as climate. This paper presents a general, dimensionless index for studying the impacts of hydrological changes in river regimes. The concept of the unit river and monthly river regime point (MRRP) is developed first and then the river regime index (RRI) is defined as the sum of MRRPs. RRI is a measure of the intra-annual flow regime of rivers ranging from completely uniform (RRI = 0) to ephemeral or dry (RRI = 1200). Data on the river Nile and its tributaries were used to illustrate the benefit and use of the RRI. The Nile was chosen as it is a long river with tributaries flowing though different climate zones. The RRI proved to be sensitive to climate and the annual distribution of excess rainfall, which decreases from upstream to downstream for the Nile in natural conditions. The impacts of lakes, wetlands and dams were clearly demonstrated. The RRI can be used to classify rivers and to study the impacts of changes in climate, base flow and river regulation. It is also useful as a tool for environmental flow allocation.

summary Groundwater–surface water interactions were studied in a Finnish esker aquifer system where some lakes suffer from periodic water level decline and others from eutrophication. Natural tracers (Ca 2+ , SiO2 and PO 3� 4 ) were used on the aquifer scale and seepage meter measurements and water level recordings on the single lake scale to better understand the complex interactions between groundwater, lakes and streams in the area. The natural tracers showed that lakes located in lower landscape positions and connected with streams were richer in tracer concentrations and that their water chemistry resembled that of the groundwater. On the other hand, closed basin lakes located at higher altitudes were nutrient-poor seepage lakes with some groundwater through flow. The data suggests that the subsurface acts as a phosphate source for the surface water bodies and the nutrient rich groundwater inseepage dictates the trophic status of the lakes in the area. The seepage meter measurements verified a strong interaction between groundwater and surface water and revealed spatial distribution of lake seepage and a temporal co-variation in lake seepage rates. A statistical analysis of seepage meter and water level observation time series were useful to show groundwater flow regimes controlling lake seepage. Using the natural tracer analysis and seepage meter measurements, we developed a novel conceptual model for the study site where the differences in lake trophic state and water table behavior were explained by assigning lakes to local and regional groundwater flow regimes. The obtained results provide new knowledge on using natural tracers in complex glacial aquifer systems and can be used in integrated groundwater–surface water management.

Lowland catchments in Finland are intensively managed, promoting erosion and sedimentation that negatively affects aquatic environments. This study quantified fine-grained bed sediment in the main channel and upstream headwaters of the River Sanginjoki (399.93 km2) catchment, Northern Finland, using remobilization sediment sampling during the ice-free period (May 2010–December 2011). Average bed sediment storage in river was 1332 g m−2. Storage and seasonal variations were greater in small headwater areas (total bed sediment storage mean 1527 g m−2, range 122–6700 g m−2 at individual sites; storage of organic sediment: mean 414 g m−2, range 27–3159 g m−2) than in the main channel (total bed sediment storage: mean 1137 g m−2, range 61–4945 g m−2); storage of organic sediment: mean 329 g m−2, range 13–1938 g m−2). Average reach-specific bed sediment storage increased from downstream to upstream tributaries. In main channel reaches, mean specific storage was 8.73 t km−1, and mean specific storage of organic sediment 2.45 t km−1, whereas in tributaries, it was 126.94 and 34.05 t km−1, respectively. Total fine-grained bed sediment storage averaged 563 t in the main channel and 6831 t in the catchment. The proportion of mean organic matter at individual sites was 15–47% and organic carbon 4–455 g C m−2, with both being highest in small headwater tributaries. Main channel bed sediment storage comprised 52% of mean annual suspended sediment flux and stored organic carbon comprised 7% of mean annual total organic carbon load. This indicates the importance of small headwater brooks for temporary within-catchment storage of bed sediment and organic carbon and the significance of fine-grained sediment stored in channels for the suspended sediment budget of boreal lowland rivers. Copyright © 2013 John Wiley & Sons, Ltd.

Several rivers around the Baltic Sea coast have poor water quality status due to occasional low pH and high metal concentrations. One potential cause of low pH is intensive drainage of shallow peat soils (

DRAINMOD 6.1 was evaluated for hydrological simulation of two drained (1.0 m drain depth, 20 m spacing) peat extraction areas in Northern Finland. Water table depth (WTD) and drainage outflow were recorded continuously during two years, and the data were used for model calibration and validation. Despite some under- and overestimation of certain events, WTD fluctuations simulated quite accurately, whereas the model did not simulate drainage outflow well compared to observed data, especially for daily runoff. Mean absolute error (MAE) was 11.29 and 9.09 cm and Nash–Sutcliffe modeling efficiency (EF) was 0.64 and 0.62 for both study sites during the validation period, indicating good agreement between predicted and observed WTD. These results demonstrate that DRAINMOD 6.1 can satisfactorily simulate the WTD fluctuations in peat extraction areas in the cold climate of northern Finland, but further studies are needed to improve the model to better include frozen condition and peat extraction activities.

Peatland drainage and peat extraction result in runoff water rich in humus, sediments, and nutrients that requires simple purification methods to prevent pollution of surface waters. Chemic...

Wetlands are commonly used to treat phosphorus from the effluent of municipal wastewater plants after conventional treatment and wastewater from various diffuse sources, with good results. The long term phosphorous (P) retention capacity of wetland treatment systems is a key research question. This study examined phosphorus retention in wetland (peat) soil columns in order to clarify the role of aluminium (Al) and iron (Fe) concentrations in wastewater on P removal. Since Al and Fe in wastewater could be expected to increase P uptake by increasing peat sorption capacity, laboratory flow-through column experiments were run for almost 700 days in conditions replicating the natural conditions in treatment wetlands. The study set comprised 18 peat columns and five water types from different origins (municipal wastewater, peat extraction runoff, distilled water with phosphate solutions containing 0.1 or 0.4 mg PO43- L-1, and pure distilled water). To study retention of sudden P peak concentrations, a high P peak was injected into the columns after about 500 days of wastewater loading. The results clearly showed that Al and Fe in input water maintained P removal in peat soils, with Al form also affecting retention processes, and P saturation did not occur. Therefore constructed wetlands can in some cases be safely used without the risk of P saturation. Furthermore, in the high P peak test, the additional P was successfully retained in columns with accumulated metals, showing that artificial addition of Al can be used to increase P retention capacity in peat soils with low sorption capacity. (C) 2015 Elsevier B.V. All rights reserved.

Large parts of the northern hemisphere are covered by snow and seasonal frost. Climate warming is affecting spatiotemporal variations of snow and frost, hence influencing snowmelt infiltration, aquifer recharge and river runoff patterns. Measurement difficulties have hampered progress in properly assessing how variations in snow and frost impact snowmelt infiltration. This has led to contradicting findings. Some studies indicate that groundwater recharge response is scale dependent. It is thus important to measure snow and soil frost properties with temporal and spatial scales appropriate to improve infiltration process knowledge. The main aim with this paper is therefore to review ground based methods to measure snow properties (depth, density, water equivalent, wetness, and layering) and soil frost properties (depth, water and ice content, permeability, and distance to groundwater) and to make recommendations for process studies aiming to improve knowledge regarding infiltration in regions with seasonal frost. Ground-based radar (GBR) comes in many different combinations and can, depending on design, be used to assess both spatial and temporal variations in snow and frost so combinations of GBR and tracer techniques can be recommended and new promising methods (auocostics and self potential) are evolving, but the study design must be adapted to the scales, the aims and the resources of the study. View Full-Text

Summary Declining lake levels (Aral Sea syndrome) can be caused by changes in climate, increased water use or changed regulation patterns. This paper introduces a novel lake geometry index (LGI) to quantify lake hydrological characteristics. The index was developed using a large representative dataset of lake hypsographic characteristics from 152 lakes and man-made reservoirs. Using the LGI index, lakes can be classified into five groups: groups 1–4 when LGI is 0.5–2.5, 2.5–4.5, 4.5–6.5 and 6.5–8.5, respectively, and group 5 when LGI is >8.5. Naturally shallow and vast lakes and wetlands fall into the first group and deep man-made reservoirs in narrow valleys are in group 5. The response of three different lake systems (LGI 0.75, 2.75 and 6.5) to different water flow scenarios was then simulated using the water balance equation. From this, the index ‘potential lake area’ (A pot ) was developed to show lake responses to changed hydro-climatological conditions. A pot and LGI can be used to classify lakes into open or closed systems. Simulations showed that lakes with low LGI have a shorter response time to flow and climate changes. As a result, the impact of water balance restoration is faster for lakes with low LGI than for lakes with high LGI. The latter are also more vulnerable to climate variation and change.

Continuous determination of suspended solids (SS) by turbidity measurements in drained peatland is expanding, increasing the demand for reliable calibration data for load calculations. Turbidity was used to estimate SS (n=333) and particulate nutrient loads (n=157) after peatland drainage for forestry in Central Finland for three study catchments. SS data from the drainage outlet correlated well with turbidity, demonstrating that turbidity can be used as an accurate measure of SS in drained peatland conditions. Measurement error was found to be approximately 8% (p

Summary Groundwater discharge from an esker aquifer to a fen was studied to understand relevant hydrological processes for groundwater-surface water interaction in an esker–peatland hillslope. Piezometric levels of the peat layer and esker sand layer were continuously monitored and compared to climate data. Groundwater exfiltration points were spatially mapped and related to peat depth. The study showed a clear interaction between fen surface water and sand esker groundwater although the hydraulic conductivity of peat was low and the peat depth thick. In the artesian aquifer beneath the fen, the piezometric head showed a clear response to precipitation and evapotranspiration. Wetting of the peat is rapidly seen as pressure increase in the confined aquifer. This provides new information on hydraulics of wetlands found in aquifer discharge areas. Groundwater exfiltrated through thick peat layers in vertical preferential point discharges demonstrating how double porosity provides flow through the peat layer with low hydraulic conductivity in the peat matrix. The “pipe flow” channels were found in the deep peat area in the transition zones from deep peat to shallow peat. Diffuse seepage through the ditch bottom was found where ditches cut into the sand layer. Increased discharge through the ditch bed reduced the flow resistance at the aquifer boundary which can lower the groundwater level in the esker. The results show new processes in the groundwater discharge zone that are useful for groundwater modelling and policy development for future groundwater protection.

Samples of groundwater, surface water, snow and precipitation were collected to identify potential end-members for aquifer recharge in an unconfined esker aquifer connected to nearby surface waters. Concentrations of Ca 2 + , Cl − , NO 3 –N and SiO 2 and electrical conductivity were determined in these water samples. Time series, ANOVA followed by HSD test and biplots were used to investigate temporal and spatial variations in surface water and groundwater chemistry. Examination of the spatial and temporal variations in groundwater solutes revealed that water quality was similar in perched groundwater and the main aquifer. The exception was NO 3 –N concentration, which increased in the perched groundwater with rising groundwater level, indicating a nitrogen source from the overlying airport. In the main aquifer, solute concentrations generally decreased during and immediately after snowmelt periods, indicating the importance of snowmelt input for groundwater quality. Groundwater solute concentrations generally decreased with declining groundwater level. During the spring melt period, the surface water level rise higher than groundwater level and the Cl − concentration in groundwater decreased showing a seasonal surface water intrusion. During the anomalously warm period in winter (T > 0 °C) the solute concentration decreased, implying that groundwater quality may be sensitive to future warming.

Peatland drainage can affect headwater systems, causing changes in bed substrate composition and hydraulic geome-try in small brooks. We studied hydraulic geometry and sediment properties in 14 boreal forest brook reaches (width < 2 m), characterised by well-vegetated banks, high sinuosity and low width-to-depth ratio, in north-east Finland. The aims were to obtain information from channel geometry and to study brook response to extensive sediment load from land use. The results indicate that bed sediment in brooks is almost continuously mobile, which negatively reflect to ecological status of the brooks. These headwater meandering parts have limited sediment transport capacity and require a long period to recover from artificially increased sediment input from peat drainage. However, different reaches can be prioritised for restoration according to the characteristics of silted bed sediment or sediment origins. Brook width appeared to have large natural variation, causing great local velocity variations. This needs to be taken into consideration when restoring straightened reaches in small headwater areas, e.g., width in restored reaches cannot be uniform but should include variations.

Evaluation of river condition is complicated by dynamic relationships between river assemblages and their environment. We assessed variation of ecological status classifications of stream diatom and macroinvertebrate communities within a boreal river system. We specifically examined whether results of ecological classifications are concordant across taxonomic groups and among main channel and headwater side tributaries of this river system. We further assessed whether ecological classifications are stable from year to year and whether classifications show predictable relationships to major stressor gradients. The estimated ecological condition varied considerably among and between reaches of main channel and tributaries for both examined taxonomic groups. Ecological classifications also differed between the two taxonomic groups and were generally lower and temporally more variable for diatoms. Ecological Quality Ratios (EQR) of the metrics were mainly related to pH representing a major disturbance gradient in our study, but in general, relationships to stressor gradients were weak. Our results suggest that ecological classifications could be weakly extrapolated among sites and, depending on the taxonomic group, also among different years in river systems disturbed by anthropogenic activities. Spatially and temporally extensive monitoring is therefore needed to reliably classify ecological condition of a water body. With this regard, it would be important to assess and monitor whole river networks instead of linear segments of large rivers.

This article presents an application of the choice experiment method in order to provide estimates of economic values generated by water quantity improvements in the environment. More importantly, this is the first choice experiment study valuing scientific information and in particular scientific information on climate change. The case study of interest is Rokua in Northern Finland, a groundwater dependent ecosystem very sensitive to climate change and natural variability. The study deals with the uncertainty about the actual dynamics of the system and the effect of future climate change by exploring whether the public values sustained provision of resources for scientific research to better understand long-term environmental changes in Rokua. Data are analysed using a nested multinomial logit and an error component model. Evidence from this study suggests that individuals are willing to pay in order to assure scientific research so as to better understand long-term environmental changes. As a result, policy should consider investing in and supporting related research. Other aspects of water management policy valued by the public are water quantity, recreation, and total land income., We gratefully acknowledge the financial support from the European Union via the 7th Framework Program GENESIS: Groundwater and dependent ecosystems: New Scientific basis on climate change and land-use impact for the update of the EU Groundwater Directive; WP-6 Groundwater systems management: scenarios, risk assessment, cost-efficient measures and legal aspects. We finally thank two anonymous referees for constructive and insightful comments

In this study, nitrate removal from aqueous solutions was studied using a nitrate selective ion exchange resin in both batch and fixed bed experiments. Nitrate retention experiments were carried out using nitrate-rich groundwater and several synthetic waters with different initial nitrate concentrations and the presence of competitive ions, such as sulfate. The equilibrium data were modeled and compared using the Langmuir adsorption isotherm and the mass action law and both models described the experimental data well. However, different values of Langmuir coefficients were obtained for different operating conditions, whereas it is possible to state all equilibrium data with a simple general equation obtained by applying the mass action law. A mathematical model (advection–dispersion equation) was solved numerically to predict the dynamic behavior of the columns. The experimental breakthrough curves from column experiments were in good agreement with the model predictions. The mass action isotherm parameters obtained from these column experiments were confirmed by the results of the batch experiments. Consequently, column behavior can be predicted from the batch equilibrium data by using the mass action isotherm. Finally, sensitivity analysis showed that the variation of dispersion coefficient between two times higher and two times lower than the base value was negligible.

Preferential flow affects subsurface flow and solute transport processes in forested glacial till soils. Preferential flowpaths (PFPs) have been detected in forest soils, with higher microbial biomass, organic carbon content and increased nitrogen cycling compared with the soil matrix. However, the role of preferential flow in phosphorus (P) cycling in forest soils is still unknown. This study characterised the P forms of a forested podzolic till soil profile in Southern Finnish Lapland using P extraction and ignition procedures, fractionation and solution 31 P nuclear magnetic resonance (NMR) spectroscopy. PFPs were identified by introducing the dye tracer Acid Blue 9 at the surface of a 1.25 m 2 study plot. The soil profile was vertically sliced and samples were collected from the unstained soil matrix and the dye-stained PFPs of each horizon of the podzol. Amorphous metal sesquioxides, naturally bound P (P ox ), total P (P t ), inorganic P (P in ), organic P (P o ), different inorganic P fractions (soluble P, Al–P, Fe–P, Ca–P, occluded P) and organic and inorganic P forms ( 31 P-NMR spectroscopy) were analysed in the samples. The concentrations of different forms of P and amorphous metal sesquioxides varied between the different PFPs and the soil matrix within the podzol soil horizons. The PFPs in soils on stone surfaces contained less amorphous metal sesquioxides, P ox and P t than the other flow regions. The PFPs related to coarse grains and roots contained equivalent or higher P ox and P t concentrations than the soil matrix. Inorganic P was present as orthophosphates and pyrophosphates, and was mainly bound with Al and Ca oxides in PFPs, but also with Fe oxides in the soil matrix. PFPs contained more occluded P than the soil matrix, especially on stone surfaces. The results indicate increased mobilisation and P losses in PFPs on stone surfaces due to enhanced mineral weathering, root uptake and leaching of P adsorbed by the sesquioxides. The results of the 31 P NMR study also showed higher proportions of pyrophosphate, orthophosphate diesters and monoesters other than phytic acid in the PFPs on stone surfaces than in the other flow regions, indicating higher amounts of labile forms of inorganic and organic P on stone surfaces than in other flow regions. To conclude, PFPs seem to have a twofold role in P dynamics: P can leach through PFPs on stone surfaces and accumulate on PFPs related to coarse grains and roots.

Summary Methodology was developed to estimate surface water–groundwater interactions in a changing climate in cold, snow-dominated regions and tested on an unconfined esker aquifer in northern Finland. The Watershed Simulation and Forecasting System (WSFS) model was used to simulate surface water levels. A coupled heat and mass transfer model for soil–plant–atmosphere systems (CoupModel) was used to simulate recharge. The CoupModel is able to simulate water flow through frozen soil. The simulated surface water level and recharge data were linked to the Groundwater Modelling System (GMS) version 6.5, and the three-dimensional groundwater flow model MODFLOW was used to study the impact of climate variability on groundwater levels and groundwater–surface water interactions. In addition, under A1B climate change scenario changes in aquifer storage and groundwater–surface water interactions were studied through the end of the 21st century. Recharge was shown to be sensitive to changes in soil frost and hence modelling approaches should include a soil frost component to account for the impact of frost on hydraulic conductivity. Under A1B climate change scenario study, groundwater recharge is projected to increase in winter months due to increase in snowmelt and decrease in soil frost depth. The spring snowmelt peak in late spring will decrease. This will reduce aquifer storage in early spring, increasing the vulnerability to summer droughts.

Groundwater in sufficient amounts and of suitable quality is essential for potable water supplies, crop irrigation and healthy habitats for plant and animal biocenoses. The groundwater resource is currently under severe pressure from land use and pollution and there is evidence of dramatic changes in aquifer resources in Europe and elsewhere, despite numerous policy measures on sustainable use and protection of groundwater. Little is known about how such changes affect groundwater dependent ecosystems (GDEs), which include various aquatic and terrestrial ecosystems above ground and inside the aquifer. Future management must take this uncertainty into account. This paper focuses on multiple aspects of groundwater science, policy and sustainable management. Examples of current management methods and practices are presented for selected aquifers in Europe and an assessment is made of the effectiveness of existing policies such as the European Water Framework Directive and the Habitat Directive in practice and of how groundwaters and GDEs are managed in various conditions. The paper highlights a number of issues that should be considered in an integrated and holistic approach to future management of groundwater and its dependent ecosystems. © 2011 Elsevier Ltd., The work was carried out as part of the GENESIS project on groundwater systems (http://www.thegenesisproject.eu) funded by the European Commission 7FP large scale project contract 226536.