Depth change in lakes and ponds: easy monitoring solutions

By Ray Valley

Aquatic Biologist and BioBase Product Expert

One of BioBase’s strengths is its simplicity. You don’t need an advanced engineering degree in hydrography to make a high quality bathymetric map with an off-the-shelf sonar device. If you have your transducer installed correctly, settings correct on your Lowrance, and achieve good coverage on your waterbody of interest, then BioBase’s EcoSound algorithm will produce a very precise, high quality bathymetric map output within minutes of upload to biobasemaps.com. The speed and ease of bathymetric mapping wins the day for many of our users, but perhaps even more valuable, is the benchmark you are setting for an unknown day in the future when something has changed on the lake and you need to have some “historical” information to understand how much change has taken place

Use Case: Monitoring Sedimentation

One of our most frequently asked questions by new users is “will BioBase measure sediment thickness or the depth of the sludge?” This was a source of a recent blog. Interestingly, the answer is different depending on how long our customers have been using BioBase. For the user who has no prior information about how deep the lake or pond is supposed to be, BioBase may not provide detailed enough information about the actual thickness of the sediment (sediment depth is correlated with EcoSound hardness but it is highly variable; see this blog for further details).  However, for the pond management consultant who happened to “BioBase” a client’s pond in 2013 while she happened to be on site for another matter and is now hearing from the client in 2019 that his pond is “filling in,” the answer about whether BioBase can tell him how much sediment has filled in is a most definite yes! For this pond consultant, it was a most fortuitous (or perhaps prudent?) thing that she decided to voluntarily map her clients pond in 2013.  Now with a 2019 survey, she can precisely quantify exactly how much sediment has accumulated and where over the 7 years by doing a simple subtraction of the depth and water volume between surveys and comparing maps.  The comparison of maps can be done a fancy GIS way like described in this blog. Or a quick and easy way through BioBase (see examples below).

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