Monday, April 29, 2013

Mapping Ponds with BioBase

As an addendum to our blog series on rapid, portable applications we wanted to experiment with a "thru-hull" mount of the 83/200 khz Lowrance HDS transducer on a kayak for mapping storm water retention ponds in an urban area of Minnesota (City of Maple Grove).  Electrician putty (sold as "Duct Seal") available for a few dollars at the neighborhood hardware store worked as a perfect medium for this application.  Follow the series of pictures and captions to see how this worked!
Electrician putty or "Duct Seal" available at most hardware stores can be used for shoot "thru-hull' applications on kayaks or canoes

Figure 2. A 83/200 Lowrance skimmer transducer secured to the hull of a polyethylene kayak by duct seal putty. Care should be taken to remove all air bubbles from the mold before pressing in the transducer
James Johnson from Freshwater Scientific Services LLC (www.fixmylake.com) gets his Lowrance HDS-5 all set to log data. 
Tracks showing a concentric circle approach toward mapping ponds smaller than 10 acres.  This one is 3 acres located in an urban area of Minnesota near Minneapolis (Maple Grove).  Data took 30-min to collect
Blue-scale bathymetric output created after 10-minutes of data processing time by Contour Innovations servers after upload.  Map was produced by 1,000 passively acquired GPS and bottom points.  All map outputs (e.g., water volume or hardness - next picture) can be analyzed in your private ciBioBase online account or exported to GIS for more sophisticated data analyses and layering
Bottom hardness automated output automatically created along with bathymetric and aquatic vegetation layers  in ciBioBase.  Areas that are maroon represent hard areas that remained from the original construction of the pond.  Soft areas are represented by the lighter brown colors and represent sand deltas from parking lot runoff.  Hardness and bathymetric outputs can be used to assess whether storm water retention ponds require maintenance and where specifically to focus efforts

5 comments:

  1. I've been mapping urban stormwater ponds using a kayak and Lowrance sonar unit for the past two years. I was excited to find that this method could also be used to collect data for use in ciBioBase. The through-hull transducer mount with duct-seal putty is simple and effective, but generally does not last more than a few weeks.

    Over the course of mapping 300 ponds, I came up with a better mounting method that gives more consistent results and is not affected by hot weather, standing water, or dirt accumulation. However, for most people, the short-term use of duct-seal will do the job perfectly.

    If you are interested in trying the duct-seal approach, there are several YouTube videos that explain how ---> http://youtu.be/GEZ9_C1iKP0


    - James A. Johnson, MS, CLM
    Freshwater Scientific Services, LLC
    www.fixmylake.com

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  3. • Using Duct-Seal to Mount a Sonar Transducer •

    I've been mapping urban stormwater ponds in the Twin Cities for the past two years using a kayak and a Lowrance sonar unit. I was very excited to find that this method could also collect data for use in ciBioBase. The duct-seal transducer mounting method is simple and effective, but generally does not hold up for more than a few weeks of heavy use (need to remove old putty and replace periodically). However, for short-term projects, duct-seal will do the job perfectly. Over the course of mapping 300 ponds, I came up with a more permanent method for mounting the transducer, but the quality of the data collected using the two mounts were the same.

    If you're interested in the duct-seal mounting method, there are several YouTube videos that explain how to do it ---> http://youtu.be/GEZ9_C1iKP0


    - James A. Johnson, MS, CLM
    Freshwater Scientific Services, LLC
    www.fixmylake.com

    ReplyDelete
  4. We've experimented with the thru hull on aluminum canoes too recently and it works but there is some modest signal extinguishment. No big deal if your ponds don't have dense aquatic vegetation, but if they do, bottom (and thus water volume calculations) could be off. We encourage experimentation and finding something that works for your needs. As always, we're here to help provide survey design advice

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  5. We've recently noticed that there is modest signal attenuation with thru-hull designs with Duct Seal. It will work fine for getting depth in clean bottom ponds, but the vegetation and bottom hardness outputs are not reliable. A better kayak design is through a scupper hole as showcased here - http://cibiobase.blogspot.com/2013/02/portable-lowrance-hds-units-and.html

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