This is an award to provide support for research on the development of an instrument that can be used to measure the velocity of water flowing in subsurface aquifers. The basis of instrument operation is the generation and observation of a migrating thermal plume in the vicinity of the heated probe. The proposed instrument will be equipped to sense the motion of groundwater by monitoring the discharge of heat from the isothermally heated cylinder to the surrounding soil as a function of location on the probe surface. Unlike presently available devices, groundwater flow is directed around rather than through the probe. This provides the instrument with the advantage of component isolation from the groundwater environment. Hence, the probe is expected to maintain excellent long term stability (years). An accurate knowledge of groundwater movement is needed as greater pressures are exerted on our available groundwater resources. The depletion and recharge of groundwater supplies as well as the migration of contaminant "plumes" through groundwater can only be predicted given a knowledge of groundwater flow characteristics. This primarily entails a complete knowledge of groundwater flow speed and direction for the zone of interest. This award was made in accord with criteria outlined in NSF 89-85, Small Grants for Exploratory Research (SGER).
