A NEW METHOD FOR MEASURING NEAR-SURFACE MOISTURE BUDGETS IN HYDROLOGICAL SYSTEMS

Preliminary results from a groundwater experiment set up near Matamata (New Zealand) reveal that confined aquifers can act as giant weighing lysimeters, with pore water pressures giving real-time measures of changes in amounts of surface and near-surface water. This opens the possibility of water balance studies at the scale of hectares using measurements from a single site. Given suitable confined aquifers, the technique has application in various environments for hydrological measurements as diverse as quantification of evapotranspiration loss, areal precipitation measurement, monitoring the water content of an accumulating snowpack, and net lateral groundwater transfers in unconfined aquifers.