ESTIMATION OF TEMPORAL CHANGES IN SOIL-MOISTURE USING RESISTIVITY METHOD

The temporal variation in a soil moisture profile can be studied using resistivity sounding data acquired at different times. The layered ea rth model based estimation of soil moisture from apparent resistivity data is a two-step non-linear inversion. Firstly, the apparent resisti vity data are inverted to derive the layer resistivity variations and thicknesses and, secondly, the moisture content is estimated from thes e layer resistivity variations using a calibration equation. The soil moisture-resistivity problem was studied using the one-dimensional for mulation of resistivity problem. A generalized geoelectric earth model was considered to simulate the soil moisture distribution and its tem poral variation in the unsaturated zone. An algorithm (RESMOS) for the interpretation of the apparent resistivity data in terms of soil mois ture variations through this two-step inversion process is reported.