Shandal Geological Field Survey System · geologicalfieldsurvey.com
Laboratory results
Hydrochemistry of surface and groundwater
Enter the major-ion analysis of one or many samples. The lab checks the ionic balance, classifies the water on the Piper, Gibbs, Schoeller, Stiff and USSL diagrams, and evaluates it for drinking against the Iraqi standard or WHO, and for irrigation against FAO and USDA criteria.
Quality control: ionic balance
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Piper diagram
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Gibbs diagrams: what controls the chemistry
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Schoeller diagram
Concentrations in meq/L on a logarithmic axis (Schoeller 1962). Parallel lines indicate waters of the same origin; crossing lines indicate mixing or different sources.
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Stiff diagrams
Each polygon is one sample: cations to the left, anions to the right, in meq/L on a common scale (Stiff 1951). The shape identifies the water type at a glance.
Drinking water
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USSL diagram: salinity and sodium hazard for irrigation
Richards (1954). Salinity classes C1–C4 from EC; sodium classes S1–S4 from SAR, with boundaries that fall as salinity rises.
Irrigation indices
Hydrochemical interpretation
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Sample locations
Markers coloured by the water-quality class. Export the results and open them in the Contour Lab to map any parameter.