Satellite data of Dutch waters can be of great value for monitoring ecology within water boards. The data can provide insight into the presence and development of various types of vegetation cover. NEO automatically measures this vegetation development with satellite data. In 2020, NEO will carry out its third duckweed monitoring assignment for Hoogheemraadschap De Stichtse Rijnlanden (HDSR).
Undesirable vegetation
Diverse plant growth is desirable in a healthy ecosystem with good water quality. When sufficient water plants are present, it creates habitat for other organisms, such as insects and fish, to develop. However, not all vegetation growth is desirable: Too many nutrients in the water can put additional pressure on the ecosystem as some vegetation species proliferate. An example is fast-growing duckweed, which can cover the water surface in a short time. This disrupts other aquatic life because of a lack of light and oxygen. Exotics such as large water pennywort can also overgrow an entire area in a short time. The locations of such fast-growing hotspots can be mapped faster with satellite data applications to support management.
Insight
In 2020, NEO will automatically monitor duckweed and various water quality parameters for the entire HDSR management area. Optical satellite data is used to map the distribution in the management area of duckweed, among others. By using multiple satellite images during the growing season, NEO gives HDSR insight into the locations, amount of biomass and rate of biomass increase in a watercourse. In 2019, measurements from satellite imagery were validated against HDSR's field measurements in the field: by using near-daily satellite imagery, satellite measurements could be compared with field measurements from the same day.
Information from the air
Monitoring the landscape with risk-driven aerial information gives a water manager an area-wide overview that he cannot get from the road. Using this information service over several years also provides a trend of the development of, for example, floating leaf plants during the growing season. Hotspots can thus be identified in advance.
