REMOTE MONITORING OF LAKE DEPTH USING MULTI-CHANNEL ACCESS TO FIELDS OF SEICHES ORIGIN

Purpose. Given limited information on depths of remote lakes, particularly in transboundary monitoring of hydrological threats, the only possibility of alarm forecasting may be remote monitoring. The purpose of the paper is develop a method of remote monitoring of the lake depth. Design/methodology/approach. Variations of the depth of lake cause variations of its characteristic oscillations (seiches). The basic principles of the method are stability of periods of damped seiches restricted by timetable of one series of oscillations, and multi-channel manifestation of oscillations of seiches origin. Findings. We examined primary metrological performance of the geophysical method of depth monitoring. The receiver, sensitivity of oscillations is based on the signal damping in the “lake?receiver” system and determines further application effect of the method. Time delay of signal interpretation is at least an interval, including the duration of signal propagation in the medium and the duration of sampling of seiches half-period. Noise immunity of the “lake?receiver” system is based on its capability to discern signals with adjusted reliability. Accidental error of the method is defined by variations of seiches periods determined by external causes. Practical value/implications. The application of a multi-channel access to signals of different physical nature with space multiplexing of oscillations provides greater receiver sensitivity and noise immunity of the “lake?receiver” system. To decrease accidental measurings error, the duration of signal observations must significantly exceed the seiches period. So, the proposed method serves for monitoring slow depth changes, particularly in over-filtration of water through the lake soil bed, the body of a dam (for example, as in filtration into soil during 2 years (as of 14.02.1994) of 5 mln. m3 of water contaminated radioactive isotopes from the Olympic tailing dump, Australia.