Cross-section Generating Campaign
To continue our cross-section generating campaign, the eE+E had to get creative in May 2019. The Acoustic Doppler Current Profiler (ADCP) was unfortunately not available for us to use in the allotted time frame, so the eE+E designed and constructed a fieldwork boat made out of PVC plumbing pipe and fittings, cargo boxes and cable ties. First, a prototype was designed and tested in Germany to make sure that the design would serve our chart-plotting purposes and, especially, survive in South African conditions. Once successful, a ‘South Africanised’ version was built with consideration of local riparian conditions thanks to our close cooperation with Dr. Marius Claassen, a veteran fieldwork specialist and Fauna and Flora expert. We named our iWaGSS fieldwork boat ‘The Boytjie’.
We mounted ‘The Boytjie’ with a chart plotting instrument so that we could draw river-bed profiles from the available x, y and z coordinates that the plotter provides. From the points we are also able to interpolate using various contour-drawing techniques that software such as ArcGIS provides. The results were, of course, not as accurate as we have come to expect from technology such as the ADCP which we used in May 2018, but the affordability and efficacy of the profiles drawn are suitable enough for what our one-dimensional hydrodynamic model requires. In fact, the technology is being used further by our German partner KIT to compare bathymetry-drawing technology created in their previous fieldwork campaign on the Phalaborwa Barrage and is also being used by a South African partner to draw bathymetry in other reservoirs and dams in the Olifants river basin. We are grateful to DIE GEWÄSSER-EXPERTEN! for the use of their chart plotter for our fieldwork campaign. The iWaGSS group have secured the use of the ADCP for future fieldwork campaigns and a comparative study will be made on the same locations using various chart plotting techniques.
Apart from this campaign, the eE+E and Dr. Marius Claassen spent some additional time in the basin doing various ground-truthing studies as well as drawing weir geometry, by hand, from important weirs that don’t have any geometry information available from the Department of Water and Sanitation (DWS). The final monitoring weirs that weren’t previously available to build into the model have now been included and can be used for calibration purposes in the future.