ViWaT-Engineering: Field test of a quality monitoring station for surface water

Monitoring
Field test for the first surface water monitoring station at Talsperre Hullern (SEBA Hydrometrie)
Monitoring
Oxygen concentration, pH, Redox potential and chlorophyll-a content at the intake of Talsperre Hullern between 27. July and 27. September (SEBA Hydrometrie)

In ViWaT-Engineering, the companies SEBA Hydrometrie and bbe Moldaenke are developing innovative monitoring stations to monitor surface water quality in the Mekong Delta. Already in October 2020, a pilot test of the first monitoring station was successfully completed in the hydraulic engineering laboratory of the Karlsruhe Institute of Technology (KIT). However, as the station could not subsequently be installed in the Mekong Delta as planned due to the COVID-19 pandemic, it was tested at the Hullern Dam (NRW) in the period from June to September 2021. It is planned to implement the station at its intended location in Vietnam later this year.

The automated and continuous monitoring of water quality in rivers and canals within Ca Mau Province in the southern Mekong Delta provides important information regarding the status and dynamics of water quality. Of particular importance here is the increasing salinization of surface waters due to seawater intrusion. This plays a crucial role in the assessment of surface waters in terms of their potential use for local water supply, which may reduce the current common groundwater overexploitation.

Therefore, automated monitoring stations will be set up at several sites selected jointly with the Vietnamese project partners as part of ViWaT-Engineering. The measuring techniques used consist of multi-sensor devices, field photometer probes(MPS-D8 and SPS-NO3; SEBA Hydrometrie) and fluorometer probes(AlgaeTorch; bbe Moldaenke). These are suitable for the simultaneous determination of a multitude of physicochemical water parameters (e.g. water level, temperature, salinity, pH, redox potential, oxygen concentration) as well as for the in-situ determination of phytoplankton (total chlorophyll-a content) and the differentiation of algae classes (e.g. green algae and cyanobacteria). In addition to the water turbidity, the nitrate concentration is also determined photometrically. With a high-performance data collector (SEBA NetLogCom) with integrated 4G modem, the continuously determined measurement data are stored and made available online on a central server for the project partners. The measurement data can be viewed graphically visualized via the web-based platform SEBA Hydrocenter. In the course of the measurements at the Hullern dam, the planned long-term operation of the measuring station in Vietnam was successfully tested. During the three-month pilot measurements, the dam operator was provided with high-resolution information on the change in raw water quality in the inflow of the dam during the dry summer months of June - September 2021 (cf. Fig.).