Bathymetric Survey

Bathymetric survey means surveying features permanently under the water, like bottom of the lakes, oceans, etc. (example: Contouring Holmes Lake in Lincoln, Nebraska). Elevation data gathered with GPS, sonar, and a data recorder/processor mounted on a boat. In order to determine sediment deposits it was necessary to calculate present volume of the lake. Actual sediment was calculated by subtracting present surface and surface when lake was constructed. Resulting contour map is shown on images below.