Partitioning young and old groundwater with geochemical tracers

摘要: Abstract Groundwater age—defined as the time elapsed since groundwater entered subsurface—is a helpful indicator of quality and renewal. Some tracer-based age calculations require assumptions about distribution ages in sample that, unfortunately, cannot be validated. Here, straightforward mixing models are developed that do not priori knowledge distributions able to quantify fraction recharged more recently than calendar year 1953 (using tritium) or within past ~ 12 thousand years carbon-14). Calculations young old can used map velocities flow systems driven by diverse climate conditions, extraction rates, rock types, topographic gradients plant populations.