Abstract
To establish a method to investigate leakage from small earth dams by measuring ground temperature at a depth of one meter, its daily range and seasonal variation and the surface temperature of the small earth dam body were measured at the Aoike Irrigation Pond in Kagawa Prefecture. The relationship between the ground temperature at a depth of one meter and the conditions of the small earth dam body surfaces, leakage paths and seepage surfaces was investigated through simulation. The results indicate that ground temperature anomalies caused by partial leakage from a low-height small earth dam can be detected by the measurement of the ground temperature at a depth of one meter on the crest of the small earth dam during summer or winter, when ground temperature differences are more likely to occur. A method to set leakage paths, seepage surfaces and fixed temperature boundaries for simulation is also presented. From the simulation of ground temperature at a depth of one meter, the width and depth of leakage paths can be estimated by determining the conditions of leakage paths and seepage surfaces that are concordant with the measured temperature values.
