The relationship between surface and subsurface waters: Water quality aspects in areas of low precipitation

In the temperate and semiarid environment the salinity of both surface and subsurface (meteoric) waters is dominated by the weathering products of soil and aquifer minerals, since even surface waters have a history of subsurface flow. In the desert environment, in contrast, surface flows are more superficial and their chemistry dominated by the aeolian salinity. This has both a marine input and a contribution from recycled salinity from surface accumulation of evaporitic minerals. Both these sources have chloride (and to a lesser extent sulphate) as the dominant anion.