To obtain a method and an apparatus in which a water leak from a water-supply pipe line buried in the ground can be detected precisely and with good efficiency.
A sensor device 2 which detects the temperature or the electric conductivity around a water-supply pipe line buried in the ground is installed. A signal from the sensor device 2 is detected on the ground. Its detection data is compared with data obtained at a time when a water leak does not exist. Alternatively, a sensor device 2 which detects the temperature or the electric conductivity around a water-supply pipe line 1 buried in the ground is provided, a means 4 by which a signal from the sensor device 2 is detected on the ground is provided, and a means 4 by which data detected by the detection means 4 is compared with data obtained at a time when a water leak does not exist is provided.
KAWAKUBO TOMOKAZU
NAKAYAMA AKIRA
