ABSTRACT
As resistivity detection depends upon the distribution in the ground of water precipitated from the sky, it was realized early on that response must be conditioned not only by the nature of the remains and the soil containing them, but also by the ‘water balance’—precipitation input and water loss by ‘evapotranspiration’, a combination of evaporation and take-up by vegetation. Experiments to quantify these effects require an undisturbed site containing features of known composition and size, available for at least a year, and precipitation data from a local weather station. Measurements are repeated along the same fixed traverse line at intervals of usually a month.
