On-water Bathymetric Survey of the 1,237-Acre Old Abe Flowage in Chippewa County Utilizing a Lowrance Integrated GPS/HD-Sonar

Abstract

Bathymetric mapping employs a diverse set of cartographic skills proceeding from the survey of lake depths to the interpolation of depth contours, and the design and printing of maps that meet DNR standards. Over the past 20 years, advances in GPS, GIS and PostScript mapping technologies have reshaped bathymetric mapping methodologies and created an opportunity to update outdated bathymetric maps. While the impact of these new technologies is evident in all three stages of bathymetric mapping, knowledge of glacial and fluvial landforms remains a critical asset for accurate mapping. The Old Abe Flowage is a riverine that flows Cornell and Jim Falls, Wisconsin in Chippewa County and is a part of the Chippewa River. The reconstruction of the Jim Falls Dam was completed on in 1985 and a sonar based bathymetric was completed in 1987. This revision provides better positional accuracy of depths with the employment of an integrated GPS/Sonar. Utilizing this technology generates hundreds of Lat/Long/Depth survey points per hour. The collection of 193,939 allows for the generation on a very detailed and accurate rendering of the bathymetric topography.