Temperature monitoring for seepage detection in dams
Distributed seepage detection uses the natural seasonal temperature variations that occur in all surface water, such as lakes, reservoirs and rivers.
The seepage flow causes a seasonal temperature variation inside the dam. With Silixa’s range of distributed fibre optic sensing technologies and fibre optic cables this seasonal temperature variation can be measured with good spatial resolution along an embankment or tailings dam. The measured data can then, via XSeepT™ (a real-time data evaluation system), be used for automatic evaluation of the seepage flow through the dam. Temperature measurements can also detect seepage flow changes that cause internal erosion.
Generally, a constant temperature indicates a minimal seepage of fluid, whilst large seasonal variations may indicate significant seepage. At increasing seepage flows the temperature in the dam will change, and the seasonal variation will increase as shown in the figure. This temperature variation is therefore dependent on seepage flow, the seasonal variation at the inflow boundary, and the distance from the boundary to the measuring point.