WasMon-CT

Under the EU Water Framework Directive (EU WFD) environmental agencies are obliged to report regularly on ecological conditions and trophic state indices of water bodies. The measurement campaigns required to fulfil these tasks are costly and time-consuming.

The State Office for the Environment of Baden-Wuerttemberg (LUBW) contracted EOMAP for multi-source water quality monitoring of more than 20 lakes within the federal state boundaries over a period of 17 years to 2017. The initiative served as a pilot project for government use of satellite-derived water quality information.

EOMAP used high-resolution sensors on Landsat 7 and 8 and Sentinel-2 in order to derive the water parameters of turbidity, Secchi disc depth, total absorption, organic absorption, chlorophyll-a and harmful algae blooms for small lakes and reservoirs. Quality indication layers as well as spatially aggregated layers were also supplied. Lake Constance, Germany’s biggest lake, was also covered by medium resolution sensors on the Sentinel-3 satellites and the MODIS instrument on the Aqua and Terra satellites to reach the highest possible temporal coverage from 2011 to 2017, dependent on environmental conditions. The datasets were pushed to a customised copy of EOMAP’s eoApp© web visualisation tool.

Baden-Wuerttemberg has no fewer than 1300 lakes bigger than 1 hectare, illustrating the potential of high-resolution satellite-based water quality monitoring for government applications. Following the LUBW pilot project, other federal or state agencies expressed their interest and began similar projects. Within the federal state of Baden-Wuerttemberg, a follow-up project to incorporate satellite data into operational measurement and reporting routines is envisaged.