Zohorský kanál

Geological structure beneath the water

Which rock lies beneath the water line (Geological Map of Slovakia 1:50,000), how old it is, how thick the Quaternary cover is and in which tectonic unit the water flows. The bedrock decides the hardness of the water, the bottom, the turbidity after rain and the abundance of springs.

The points follow the water line (for a stream and a basin, fishing district after fishing district). The strip is a cross-section by distance, not a map; the width of a section corresponds to the number of points.

• River alluvium100%SR 72 %

marker on the bar: share among all sample points on streams in Slovakia

River alluvium: Gravelly and sandy bottom and floodplains; the water is replenished from groundwater in the alluvium.

Geological age of the rocks

• Quaternary100%

Most common rock units

Quaternary cover

• fluvial sediments of terraces50%SR 3.1 %
• fluvial sediments of floodplains25%SR 68 %
• proluvial sediments25%SR 1.1 %

marker on the bar: share among all sample points on streams in Slovakia

• Typical thickness of the Quaternary cover7.5m

• 5 – 10100%SR 20 %

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Tectonic division

• NEOALPÍNSKE TEKTONICKÉ ŠTRUKTÚRY ZÁPADNÝCH KARPÁT100%SR 84 %

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Neotectonic units

• positive unit (lowland hills)67%SR 14 %
• negative unit (lowland plains and basins, neotectonic depressions)33%SR 13 %

marker on the bar: share among all sample points on streams in Slovakia

Direction of neotectonic movements

• medium uplift67%SR 32 %
• medium subsidence33%SR 6.8 %

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Regional geological division

• intramontane basins100%SR 44 %

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Regional geological division (subunits)

• Vienna Basin100%SR 4.0 %

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Engineering-geological districts

• region of lowland-stream deposits67%SR 20 %
• region of aeolian sands33%SR 0.1 %

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Engineering-geological formations

• formation of Quaternary sediments100%SR 71 %

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Susceptibility of the area to slope deformations

• Region of stable areas100%SR 95 %

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The map covers 4 of 6 points on the water line.

Hydrogeology: aquifers and groundwater

Streams and rivers are fed by groundwater. Hydrogeological maps show in which rocks the water is stored, how permeable they are and what the water in them is like. The data come from ŠGÚDŠ maps, not from measurements at a particular water.

Aquifer rocks (hydrogeological map 1:200,000)

• Gravel75%SR 52 %
• Sand25%SR 3.9 %

marker on the bar: share among all sample points on streams in Slovakia

Aquifer type

• Zvodnence s prevažne medzizrnovým typom priepustnosti (prevažne nespevnené sedimenty) (Gravel; Fluviálne)75%SR 27 %
• Zvodnence s prevažne medzizrnovým typom priepustnosti (prevažne nespevnené sedimenty) (Sand; Eolické)25%SR 0.3 %

marker on the bar: share among all sample points on streams in Slovakia

Main hydrogeological region

• Quaternary and Neogene of the southern and southeastern parts of the Borská lowland67%SR 0.0 %
• Quaternary of the Morava from Brodské to Vysoká pri Morave33%SR 0.0 %

marker on the bar: share among all sample points on streams in Slovakia

Genetic type of groundwater

• potamogenic mineralization40%SR 4.1 %
• silicate-carbonate, silicate-sulphidogenic mineralization40%SR 1.1 %
• silicate, or silicate-sulphidogenic mineralization20%SR 2.0 %

marker on the bar: share among all sample points on streams in Slovakia

Chemical type of groundwater

• Ca-HCO3, or Ca-SO4-HCO3, or Ca-SO440%SR 3.4 %
• Ca-HCO3, or Ca-HCO3-SO4-NO3, Ca-SO4-HCO3-NO340%SR 0.9 %
• Ca-HCO3, or Ca-SO4-HCO3 type20%SR 1.7 %

marker on the bar: share among all sample points on streams in Slovakia

Groundwater quality class

• C75%SR 4.3 %
• H25%SR 8.8 %

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Geothermal groundwater bodies

• Vienna Basin100%SR 3.6 %

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Surface water chemistry according to the atlas

Modelled composition of the water in the area the fishing district line runs through. The rasters of the Geochemical Atlas of Slovakia (surface waters) are an interpolation of measurements in sampled streams, so they show the typical background of the area, not a measurement in a particular stream.

Ionic composition of the water

Water type by dominant ions: Ca–HCO₃–SO₄

Shares are in equivalents, the usual way of comparing the composition of waters.

Major ions

• SulphatesSO4117 mg/lpercentile 92
• ChloridesCl41.4 mg/lpercentile 87
• PotassiumK7.51 mg/lpercentile 87
• SodiumNa26.1 mg/lpercentile 86
• CalciumCa90.2 mg/lpercentile 80
• MagnesiumMg22.5 mg/lpercentile 72
• FluoridesF0.134 mg/lpercentile 59
• BicarbonatesHCO3225 mg/lpercentile 54

dot: average along the water line, line: from the lowest to the highest value, scale: position among sample points on streams in Slovakia (0 to 100th percentile)

Nutrients and organic pollution

• PhosphatesPO41.04 mg/lpercentile 95
• Chemical oxygen demandChSK6.23 mg/lpercentile 89
• AmmoniumNH40.372 mg/lpercentile 82
• NitratesNO312.2 mg/lpercentile 80

Metals

• ManganeseMn104 μg/lpercentile 80
• ZincZn12.9 μg/lpercentile 74
• AluminiumAl68.6 μg/lpercentile 51
• IronFe0.103 mg/lpercentile 50

Elements in river sediments

The Geochemical Atlas of Slovakia (river sediments) describes what the river carries in the fine material on its bed. Sediment collects metals from rocks, ore occurrences and past mining and industry. It is not a legal limit or a health risk assessment: it shows how an element on this stream ranks among streams in Slovakia.

Potentially toxic and trace elements

• MolybdenumMo1.62 mg/kgpercentile 95
• SeleniumSe0.865 mg/kgpercentile 95
• ZincZn242 mg/kgpercentile 92
• CopperCu54.1 mg/kgpercentile 90
• BismuthBi0.487 mg/kgpercentile 89
• CadmiumCd0.603 mg/kgpercentile 89
• NickelNi39.1 mg/kgpercentile 88
• AntimonySb3.04 mg/kgpercentile 87
• MercuryHg0.346 mg/kgpercentile 85
• TinSn3.49 mg/kgpercentile 74
• ArsenicAs8.55 mg/kgpercentile 69
• CobaltCo9.56 mg/kgpercentile 66
• LeadPb16.3 mg/kgpercentile 54
• ChromiumCr69.2 mg/kgpercentile 45
• VanadiumV55.3 mg/kgpercentile 18

dot: average along the water line, line: from the lowest to the highest value, scale: position among sample points on streams in Slovakia (0 to 100th percentile)

Natural radioactivity and radon

Airborne gamma-ray spectrometry by ŠGÚDŠ measures radiation from potassium, uranium and thorium in rocks and soil. Granites and some acidic volcanic rocks have the highest values, limestones and floodplains the lowest. Caesium-137 is a remnant of fallout from the Chernobyl accident and nuclear weapons tests.

• Equivalent thorium (eTh)eTh6.67 ppm23th percentile
• Potassium (K)K1.20 %percentile 21
• Equivalent uranium (eU)eU1.76 ppm4th percentile

dot: average along the water line, line: from the lowest to the highest value, scale: position among sample points on streams in Slovakia (0 to 100th percentile)

• Areal activity of 137CsCS1371,297 Bq/m²percentile 38

Radon risk by isopleths

• low80%SR 36 %
• medium20%SR 64 %

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Geophysical fields: magnetics and gravity

Maps of the magnetic field and gravity (ŠGÚDŠ) reveal what lies beneath the sediments and the surface: volcanic bodies, faults and crustal thickness. For an angler they are interesting indirectly: they show where the bedrock changes, and with it the water.

Geothermal potential

The Atlas of Geothermal Energy of Slovakia records rock temperature and heat flow from the Earth's interior. It is the potential of the area, not the actual warmth of the water in the stream. Specific geothermal boreholes and springs near this water are in the geothermal energy section below.

Geothermal groundwater bodies beneath the water line

• Vienna Basin100%SR 3.6 %

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Relief, climate and soils

A basin is not just water: slope and elevation determine the speed of runoff, climate the temperature and amount of water, and soils what is washed into the stream. The data come from the geomorphological division, climatic-geographical types and soil maps of ŠGÚDŠ.

• Elevation of geomorphological units (from–to)132–216m a.s.l.
• Average elevation of the units151m a.s.l.
• Average slope0.6°
• Average January temperature-2.5°C
• Average July temperature20.0°C
• Annual precipitation590mm

Geomorphological units

• Borská Lowland100%SR 2.2 %

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Geomorphological regions

• Záhorie Lowland100%SR 2.5 %

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Climatic-geographical types

• lowland climate100%SR 38 %

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Susceptibility of soils to acidification

• soils very susceptible to acidification100%SR 2.4 %

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Soil contamination (map 1:500,000)

• relatively clean soil83%SR 53 %
• uncontaminated soil, the geogenically determined content of some risk elements reaches limit values A17%SR 45 %

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Lithogeochemical types

• Neogene100%SR 48 %

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Map of the corridor

Where the nearest mine workings, deposits, burdens, geothermal boreholes and gold finds are. Groups can be switched off.

Trace elements in surface waters

Arsenic, antimony, cadmium, lead, copper, zinc and other elements in samples from rivers and streams (Geochemical Atlas of Slovakia, surface waters, 2015). The bar shows where the highest value lies among all samples in Slovakia; the light marker is the median of the samples at this water.

• AntimonySbhigh (top 5 %)
  highest 5.00 μg/lmedian 0.500 μg/l17 samples76 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: kanál pretekajúci V okolo Záhorskej Vsi, cca 1 km od obce2003, 740 m from the water. Comparison: percentile 95 of all samples in Slovakia.

• BariumBaelevated (top 10 %)
  highest 113 μg/lmedian 61.0 μg/l17 samples
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: ľavostranný prítok Zohorského kanála 1 km V od kóty 1452003, 150 m from the water. Comparison: percentile 93 of all samples in Slovakia.

• LeadPbslightly elevated
  highest 3.00 μg/lmedian 2.50 μg/l17 samples94 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: Malina, potok2003, 600 m from the water. Comparison: percentile 87 of all samples in Slovakia.

• ArsenicAsslightly elevated
  highest 3.00 μg/lmedian 0.500 μg/l17 samples53 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: Močiarka, potok2003, 980 m from the water. Comparison: percentile 83 of all samples in Slovakia.

• CopperCuslightly elevated
  highest 3.50 μg/lmedian 1.00 μg/l17 samples53 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: kanál pretekajúci V okolo Záhorskej Vsi, cca 1 km od obce2003, 740 m from the water. Comparison: percentile 83 of all samples in Slovakia.

• LithiumLislightly elevated
  highest 16.0 μg/lmedian 5.00 μg/l17 samples65 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: Stupavský, potok2003, 510 m from the water. Comparison: percentile 80 of all samples in Slovakia.

• ChromiumCrslightly elevated
  highest 2.00 μg/lmedian 1.00 μg/l17 samples94 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: Zohorský, kanál2003, 100 m from the water. Comparison: percentile 75 of all samples in Slovakia.

• SeleniumSebelow half of Slovakia
  highest 0.500 μg/lmedian 0.500 μg/l17 samples100 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: Stupavský, potok2003, 510 m from the water. Comparison: percentile 46 of all samples in Slovakia.

• CadmiumCdbelow half of Slovakia
  highest 0.150 μg/lmedian 0.150 μg/l17 samples100 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: Stupavský, potok, 510 m from the water. Comparison: percentile 26 of all samples in Slovakia.

Major ions, mineralisation and pH

Basic water chemistry: which rocks the minerals in it come from.

• Silicon dioxideSiO2slightly elevated
  highest 24.3 mg/lmedian 9.51 mg/l17 samples
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: Močiarka, potok2003, 980 m from the water. Comparison: percentile 82 of all samples in Slovakia.

Gold and ore minerals in river sediments

Regional panning prospecting: the heavy fraction was washed out of river gravel and the mineral grains in it were counted. The map of finds is positive: a sample without gold is not listed in the atlas, so the absence of a find is not proof that there is no gold.

• Ilmenit (FeTiO₃)21 samples, at most 1815 grains
• Rutil (TiO₂)21 samples, at most 315 grains
• Magnetite (Fe₃O₄)20 samples, at most 155 grains
• Monazit ((Ce,La,Nd)PO₄)20 samples, at most 55 grains
• Kasiterit (SnO₂)18 samples, at most 9 grains
• Anatas (TiO₂)18 samples, at most 55 grains
• Hematite (Fe₂O₃)14 samples, at most 55 grains
• Limonite (FeO(OH)·nH₂O)9 samples, at most 5 grains
• Pyrite (FeS₂)8 samples, at most 55 grains
• Barite (BaSO₄)7 samples, at most 5 grains
• Gold (Au)1 sample, at most 1 grains

Nearest samples with gold

Rock-forming and accessory minerals

• Amfiboly (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂)21 samples, at most 815 grains
• Andaluzit (Al₂SiO₅)21 samples, at most 55 grains
• Epidot (Ca₂(Al,Fe)₃Si₃O₁₂(OH))21 samples, at most 555 grains
• Granáty ((Fe,Mg,Ca,Mn)₃Al₂Si₃O₁₂)21 samples, at most 4115 grains
• Pyroxény ((Mg,Fe,Ca)₂Si₂O₆)21 samples, at most 815 grains
• Staurolit (Fe₂Al₉Si₄O₂₃(OH))21 samples, at most 555 grains
• Zirconium (ZrSiO₄)21 samples, at most 315 grains
• Tourmalines (complex borosilicate)20 samples, at most 155 grains
• Kyanit (Al₂SiO₅)20 samples, at most 55 grains
• Sillimanit (Al₂SiO₅)20 samples, at most 5 grains
• Spinel (Cr-spinel) ((Mg,Fe)(Al,Cr)₂O₄)18 samples, at most 5 grains
• Titanit (CaTiSiO₅)4 samples, at most 40 grains

Groundwater: chemistry, water types and radioactivity

Hydrogeochemical objects (analyses of springs and boreholes), the geochemical atlas of groundwater (1996) and radiohydrochemical sampling. Groundwater feeds streams, so its composition also affects the water in the stream.

Chemical water types nearby

• Ca-HCO37×
• Ca-Mg-HCO3-SO46×
• Ca-SO4-HCO36×
• Ca-SO43×
• Ca-Mg-SO4-HCO33×
• Ca-Mg-NO3-SO42×
• Ca-Mg-HCO32×
• Ca-Na-HCO32×

Water quality class according to the hydrogeochemical map

• class H17×
• class D14×
• class C4×
• class E3×
• class B2×
• class F1×
• class G1×
• class A1×

Metals in groundwater

• LeadPbextreme (top 1 %)
  highest 34.0 μg/lmedian 0.500 μg/l43 samples67 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: vrt1994, 2.6 km from the water. Comparison: percentile 99 of all samples in Slovakia.

• ChromiumCrextreme (top 1 %)
  highest 17.2 μg/lmedian 1.00 μg/l43 samples14 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: studňa1994, 2.7 km from the water. Comparison: percentile 99 of all samples in Slovakia.

• AluminiumAlextreme (top 1 %)
  highest 0.670 mg/lmedian 0.0200 mg/l43 samples23 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: drén1994, 1.4 km from the water. Comparison: percentile 99 of all samples in Slovakia.

• ArsenicAsextreme (top 1 %)
  highest 21.0 μg/lmedian 0.500 μg/l43 samples51 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: studňa1994, 1.6 km from the water. Comparison: percentile 99 of all samples in Slovakia.

• CadmiumCdextreme (top 1 %)
  highest 4.00 μg/lmedian 0.250 μg/l43 samples93 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: vrt1994, 2.3 km from the water. Comparison: percentile 99 of all samples in Slovakia.

• CopperCuhigh (top 5 %)
  highest 10.1 μg/lmedian 1.30 μg/l43 samples
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: studňa1994, 2.9 km from the water. Comparison: percentile 97 of all samples in Slovakia.

• AntimonySbhigh (top 5 %)
  highest 1.80 μg/lmedian 0.100 μg/l43 samples60 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: studňa1994, 2.9 km from the water. Comparison: percentile 97 of all samples in Slovakia.

• LithiumLihigh (top 5 %)
  highest 74.0 μg/lmedian 13.0 μg/l43 samples
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: studňa, 2.0 km from the water. Comparison: percentile 96 of all samples in Slovakia.

• ZincZnhigh (top 5 %)
  highest 1,910 μg/lmedian 87.0 μg/l43 samples
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: studňa, 2.4 km from the water. Comparison: percentile 96 of all samples in Slovakia.

• MercuryHghigh (top 5 %)
  highest 0.200 μg/lmedian 0.100 μg/l43 samples88 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: studňa1994, 960 m from the water. Comparison: percentile 95 of all samples in Slovakia.

• SeleniumSeelevated (top 10 %)
  highest 2.00 μg/lmedian 0.500 μg/l43 samples86 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: studňa1994, 2.5 km from the water. Comparison: percentile 92 of all samples in Slovakia.

• IronFetypical value
  highest 0.00500 mg/lmedian 0.00500 mg/l3 samples100 % below the limit of quantification
  1. up to 50 %
  2. 50–75
  3. 75–90
  4. 90–99
  5. above 99

  Highest value: studňa1994, 1.8 km from the water. Comparison: percentile 50 of all samples in Slovakia.

Radon in waters

Mine workings, deposits and ore occurrences

Old mine workings outside mining areas (Geofond register), deposits and mining areas, and the metallogenetic map. Gold, silver and other metals near streams can get into sediments and water.

Deposits and mining areas

Boreholes and Geofond archive reports

Register of hydrogeological boreholes, other boreholes and geothermal boreholes. Each borehole has a report in the Geofond archive (geological profiles, pumping tests, chemical analyses of the water); the report number is in the table.

1,145 boreholes in the 3 km zone, of which 74 hydrogeological and 1071 other; with an archive report number 882.

Borehole depths

• up to 10 m685×
• 10–30 m117×
• 30–100 m40×
• 100–300 m99×
• over 300 m82×

Nearest boreholes

Environmental burdens, landfills and anthropogenic sediments

Recorded environmental burdens (industrial sites, landfills, mining), the register of waste landfills and monitoring of anthropogenic sediments (industrial sludge). It is a list of places, not a measurement of water pollution.

Environmental burdens

Waste landfills

Landslides and slope deformations

Register of documented slope deformations (Geofond). Landslides by a stream can bring fine material into the water, change the bed and dam the channel.

Types of deformations

• Landslides2×

Degree of activity

• Aktívny2×

Current state

• SD prebraná z archívnych materiálov (existuje inž. geologick2×