Hydrogeology. Kevin M. Hiscock

soil moisture deficit mm STP standard temperature and pressure of gases (0 °C, 1 atmosphere pressure) Sv sievert (unit of dose equivalent that accounts for the relative biological effects of different types of radiation; 1 Sv = 100 rem) s groundwater level drawdown m s solubility g (100 g)⁻¹ solvent T transmissivity m² s⁻¹ T absolute temperature K TDS total dissolved solids mg L⁻¹ TOC total organic carbon mg L⁻¹ t time s t _1/2 radionuclide half‐life s V volume m³ V volt (electrical potential) V _s volume of solid material m³ VOC volatile organic compound V_SMOW Vienna Standard Mean Ocean Water v groundwater or river water velocity m s⁻¹ average linear velocity (groundwater) m s⁻¹ average linear contaminant velocity m s⁻¹ average linear water velocity m s⁻¹ WHO World Health Organization WMO World Meteorological Organization WMWL World Meteoric Water Line W(u) well function w width m ZFP zero flux plane z (hydraulics) elevation m z (chemistry) electrical charge

       Greek symbols

Symbol	Description	Units
α	aquifer compressibility	m^2 N^−1 (or Pa^−1)
α	aquifer dispersivity	m
α	isotope fractionation factor
β	water compressibility	m^2 N^−1 (or Pa^−1)
γ (chemistry)	activity coefficient	kg mol^−1
γ (hydraulics)	specific weight	N
δ	stable isotope notation
δ−	partial negative charge
δ+	partial positive charge
θ	volumetric moisture content
λ	radionuclide decay constant	s^−1
μ	viscosity	N s m^−2
μ/ρ	kinematic viscosity	m^2 s^−1
ρ	fluid density	kg m^−3
ρ b	bulk mass density	kg m^−3
ρ s	particle mass density	kg m^−3
σ e	effective stress	Pa (or N m^−2)
σ T	total stress	Pa (or N m^−2)
T	total competing cation concentration	meq (100 g)^−1
∑	sum of
Φ	fluid potential