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Fluvial sediment samples (river bottom sediment, suspended sediment and active floodplain/overbank) were collected in 2 baseline stations of the Transnational Monitoring Network for each of the 12 countries in the Danube Basin Region: Austria, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic, Hungary, Republic of Moldavia, Montenegro, Romania, Republic of Serbia, Slovakia and Slovenia, according to a harmonized methodology. The sediment samples were analyzed for selected hazardous substances (HSs):8 metals, 8 polycyclic aromatic hydrocarbons (PAHs) and 6 pesticides in an accredited laboratory selected as reference laboratory, as well as in national laboratories. Risk ratios were computed in order to compare the results to the Environmental Quality Standards listed in the European Directives, to the national threshold values in the Danube Basin, and to other available international European and American quality standards, and the risk ratios were classified as background, alert and intervention values for readily evaluation. Results show widespread metal(oid) (As, Cd, Cu, Hg, Pb, and Zn) contamination in the Danube Basin, most often associated with historic mining. Concentration values of Ni and Cr exceeding the thresholds are caused by the geological background (ultrabasic and metamorphic rocks in Bosnia and Herzegovina, Republic of Serbia and Romania). Concentration values higher than the thresholds for some of the PAHs (e.g. Fluoranthene) and sometimes for Total PAHs were also noted almost in every countries, caused by industrial activities, wastewater discharges or navigation on the Danube River. Pesticides were below the detection limit or below the legislative intervention thresholds at all national baseline sampling sites.

Discharge of hazardous substances (HSs) in hydrographic basins represent a danger to aquatic biological activity and water supplies and can severely pollute surface water sediments. The increase of pollution in the Danube Basin requires the implementation of systematic monitoring and evaluation of the sediments quality as dictated by the EU Water Framework Directive. For this system development, applicable in mountainous conditions, the Upper Tisa region in the northwest part of Romania on the border with Ukraine, Hungary and Slovakia was selected as a test area. Sampling of overbank (floodplain) sediment, river bottom sediment and suspended sediment was carried out at 10 locations in the test area in order to analyze the concentration and distribution of eight metal(oid)s (Cu, Pb, Zn, Cd, Hg, Ni, Cr and As), in addition to 3 organic components (anthracene, fluoranthene, benzo(e)pyrene) as hazardous substances (HSs). The sediment quality assessment was carried out according to the 2013/39/EU Directive and EU Water Framework Directive standards. Most of the analyzed HS concentrations in river bottom sediment and overbank (floodplain) sediments fall within the limits of environmental quality standards (EQS). As, Cu, Pb, and Zn tend to exceed the EQS at some locations. The highest exceedances were recorded for Pb, for which contents of up to 987 mg/kg were detected. The highest contents were found in the overbank sediments sampled, and the lowest in river bottom sediments, which may indicate historical pollution. Mercury contents in overbank sediment samples exceed all standards, while cadmium content is below the international standards. Anthracene, fluoranthene and benzo(e)pyrene concentrations in overbank and bottom sediments comply with international standards. A few samples in suspended sediments slightly exceed the lowest environmental standard value (i.e., Romanian normal value). HS concentrations remain low in the suspended sediments showing that it is not the main transport route for pollution in this area. HS contents decrease gradually from upstream to downstream due to dilution along the river course. In the last testing point at Someș Aciua, the concentration of metal(oid)s measured in the sediments remain below the EQS limit values, thus there is no risk of transboundary pollution. The main source of metal(oid) contamination is historic base-metal ore mining and the associated mine waste sites in the Baia Mare and other mining areas scattered around the whole region. The main source of the studied organic compounds is the incomplete or low-temperature coal combustion processes that occur in households in rural areas.

The EU Water Framework Directive requires the monitoring and evaluation of surface water sediment quality based on the assessment of risk posed by contamination on the biotic receptors. Fluvial sediments are important receptors of hazardous substances (HSs) pollution from the upstream catchment areas in the Danube River Basin (DRB). For the development of systematic sediment quality monitoring and evaluation, the Drava River region on the border of Hungary and Croatia was selected as a test area representative of lowland hydromorphological conditions. Overbank (floodplain) sediments and river bottom sediments (stream sediments) were sampled at two depths at 9 locations in the test area. Eight heavy metal(oid)s were analyzed As, Cd, Cr, Cu, Hg, Ni, and Zn as hazardous substances. The sediment quality assessment was carried out according to the 2013/39/EU Directive and EU Water Framework Directive standards. Most of the analysed HS concentrations in river bottom sediment and overbank (floodplain) sediments fall within the limits of environmental quality standards (EQS). Results show that there is no significant differences in metal(oid) HS concentrations among the various sediment types and between shallow (0- 5cm) and deeper (stream sediment: 5-10cm ; floodplain sediment: 40-50cm) sediment which suggests that the large lowland Drava River fluvial system is an extensive single fluvial system with homogeneous distribution of sediments and the associated contaminants. Specifically, the studied sediments in the tributaries of the Drava River do not seem to be contaminated with metal(oid) hazardous substances but at certain sites concentrations are elevated above the environmental limit values, especially for As and Zn, and to lesser extent for Cr. The data analysis techniques used enabled the identification of sites with anthropogenic pollution and the recognition of regional pattern in HSs distribution.

This study demonstrates the use of digital image processing for the spatial pattern recognition and characterisation of Ni concentrations in topsoil in Europe. Moving average smoothing was applied to the TIN-interpolated grid model to suppress small irregularities. Digital image processing was applied then to the grid. Several NE-SW, E-W and NW-SE oriented features were revealed at the continental scale. The dominant NE-SW linear features follow the Variscan and Alpine orogenies. The highest variability zones are in the Alps and the Balkans where mafic and ultramafic rocks outcrop. A single major E-W oriented north-facing feature runs along the last continental glaciation zone. This zone also coincides with a series of local maxima in Ni concentration along the glaciofluvial deposits. The NW-SE elongated features are located in the Pyrenees, northern Italy, Hellas and Fennoscandia. This study demonstrates the advantages of digital image processing analysis in identifying and characterising spatial geochemical patterns unseen before on conventional colour-surface maps.

International audience; The ThermoMap project (http://www.thermomap-project.eu/) is an EC co-funded project (FP7-ICT Policy Support Programme) and focuses on mapping very shallow geothermal energy potentials (vSGP) in Europe. Geothermal energy, as defined in the directive on renewable energy sources from 2009, is energy in the form of heat beneath the Earth's surface. Horizontal and vertical heat exchangers and other very shallow heat exchange systems including ground source heat pumps (GSHP) are effective devices to exploit the energy of the shallow underground. The key objective of the project is to provide an appropriate visualisation of the estimated very shallow geothermal energy potential by using a specially developed open-source web mapping (WebGIS) application running in a web browser on the Internet. ThermoMap collects, harmonises, combines, analyses and validates available pedological, climatological, topographical, geological, groundwater and administrative (meta-)data to estimate the shallow geothermal energy potential at depths up to ten metres below surface. A multitude of further background information on a medium scale (European Outline Map) to regional and local scale (14 Test Areas) across Europe has been derived. The results show variations of temperature and heat flow at depths up to ten metres. These variations are controlled by internal soil properties like texture, moisture, pore size distribution (characteristic air and water balance) and bulk density as well as climatic conditions (temperature, precipitation) and hydro-/geological parameters (groundwater level, saturation conditions) . Using the approach and formulas according to Kersten (1949) and Dehner (2007) geothermal energy potentials have been calculated with a resulting spatial dataset of heat conductivity values in W/(m*K) and volumetric heat capacity in MJ/(m3*K). The GIS pre-processing takes into account parameters such as legal constraints, slope and unsuitable soil types as well as the availability of the softrock zone required for the efficient installation and operation of different horizontal and vertical heat collector systems. One main output of the project work is a WebGIS-based open-source mapping application named ThermoMap MapViewer (http://thermomap.edu-zgis.net/). The contained visualised geodata consists of the technically and semantically harmonised, processed and analysed datasets from each case study area. No spatial analysis is performed by the web mapping application, it acts as a central portal visualising pre-processed GIS results collected from distributed databases via Web Map Services from each project country partner. For end-users of the developed estimation system, four possible target groups have been identified: research, industry, public and public agencies. The different target groups are invited to use the WebGIS interface according to their different needs. In tailoring the demands and needs of the end-users, graduated information levels within the MapViewer application were developed. These are represented by different 'Info Tools' allowing for differing levels of focus, content, terminology, data volume and information scope. For the general end-user a special query tool was created that displays interpreted information which can also be downloaded as PDF-file or printed as a 'Location Information Sheet' enriched with map details, diagrams and tables. To ensure a continual validation and improving of the ThermoMap R&D outcomes, a testing phase in the form of user seminars has been performed and evaluated. Additionally, modelling results have been cross-validated with field measurements and laboratory analyses of key characteristics such as soil texture, bulk density, and heat conductivity. The appropriate evaluation of both activities will create not only valuable feedback for an enhancement of the user-friendliness of the WebGIS service, but also provides the consortium with comparable measured data to be able to validate the developed process concept as well as to improve the accuracy of the ThermoMap estimation system for the very shallow geothermal potential (vSGP) across Europe.