CARIS/MIWB Lake Survey 2015 Results

Following two previous editions, on the Spiegelplas (Nederhorst den Berg, The Netherlands) in 2013 and Wijdeblik (Kortenhoef, The Netherlands) in 2014, the third edition of the Lake Survey project was held on the Vlietland in Leidschendam, The Netherlands. CARIS joined forces with Fugro Survey BV to organise a practical survey week for the third-year students of the Maritime Institute Willem Barentsz (MIWB). During the week the students went through the entire surveying process from survey platform mobilisation to product generation.

Before it became a lake, Vlietland used to be a polder. Vlietland’s formation started late 1969 when sand was excavated for use in civil engineering projects. Due to the nature of the lake it has some specific and interesting bottom features. The bottom varies significantly with depths up to 37 metres. Nowadays the lake is used for recreational purposes. Although this made it challenging to survey, during the nice weather that was experienced, a couple of wrecks were found. Also, to ensure the water quality, a pipeline that blows air into the water column is laid out on the bottom. Normally bubbles disturb the sonar’s echoes, but in this case they were used to trace the pipeline. Together, all these characteristics made Vlietland a very interesting survey area.

With 18 students it was a much bigger group than previous years. The students were split up into 5 smaller groups and were offered a varying programme with boatwork-, GNSS-, processing- and cartographic workshops. The survey motor boat, Fugro Calibrator, was moored in the Vlietland marina and the facilities around it were used to accommodate the computers and equipment used during the workshops. The students and representatives from CARIS and Fugro put up camp on the Vlietland campsite next to the lake.

Data was collected with an R2Sonic 2022 multibeam system. Positioning was done with Starfix and this was also an additional subject in the GNSS workshop. CARIS HIPS and SIPS was used to process the bathymetric data after which the surface analysis and cartographic product creation was completed with CARIS BASE Editor. The students really got to experience all the different steps in a survey campaign. The weather, with temperatures exceeding 30 degrees Celsius, also helped to make it a memorable week. At the end of the week a complete dataset of the Vlietland Lake was collected. A sample of the dataset is available for download together with CARIS Easy View.