Abstract

It is known that rainwater infiltrating into soil tends to drop infiltrating velocity to the vertical direction and tends to flow horizontally when it reaches an unpermeable layer. Therefore it is necessary to determine exactly the location and depth of the groundwater vein stream flowing above the unpermeable layer for effectively using groundwater.

In order to accomplish this, an electric resistivity survey and an electric logging have been carried out. The information on the location of the groundwater is obtained by these methods. It is very difficult though to obtain information on the location and depth of flowing groundwater in vein streams.

The authors developed an underground temperature survey method to detect the accurate information on groundwater vein stream. This method uses the difference between temperature of flowing groundwater and ground temperature of a shallow layer. It is composed of a one-meter- depth temperature survey, a multiple point's temperature logging and/or usual temperature logging, and a flowing direction and a velocity measurement.