A healthy natural environment is important for social wellbeing and for the economy. That is why the government wants to preserve and strengthen the natural environment of the Netherlands. Biodiversity is in decline all over the world. The number of species of animals, plants and microorganisms is decreasing. The National Ecological Network (NEN) is made up of existing and planned nature areas. It is known as the Main Ecological Structure, or EHS, in legislation. The network is designed to link nature areas more effectively with each other, and with surrounding farmland. The NEN encompasses: existing nature conservation areas, including the 20 National Parcs; areas where new wildlife habitats are being created; agricultural land under nature-friendly management; over six million hectares of water: lakes, rivers, the North Sea coastal zone and the Wadden Sea; all Natura 2000 areas.
To be able to assess the health and overall state of nature periodically, monitoring is essential as input for management decisions. Time series of geo-data are used as basis for nature monitoring and to determine trends. Basic indicators relate to the area, fragmentation and the quality of the various ecosystems. As technology, scientific methods and policies influencing observation efforts keep evolving so is the compilation of the geo-data. For example topographical maps were initially based on fieldwork data, but are currently derived from aerial photographs and satellite imagery impacting the comparability of geo-data representing specific land use in different periods.
How do the data anomalies in timeseries of geodata, that occur as result of technological and policy changes, impact the quality of the nature trend indicators?
Technical team of a cartographer a Remote Sensing specialist, a GIS specialist and a Bayesian Statistics expert.
Peer group of two ecologists, a forester, a reporter and specialists of the Dutch Environmental Agency.
During 5 half-a-day workshops the technical team analysed the trends while adding completeness and precision in every iteration. After 3 workshops the first out of three peer meetings were organised in which results were presented and feedback gathered as input for a next iteration.
A test area of 30x25 km at a 25x25 m resolution: Protected areas and 4 editions of the nature landuse map of the Netherlands (BasisKaartNatuur) for the years: 1990, 2004, 2009 and 2013. The maps distinguish between: Build up area and infrastructure, Water, Arable land, forest, heath lands, reed swamps, drifting sands, dunes, beaches and sandbanks; natural grasslands and other graslands
Results and impact
For the test area one percent of all landuse transitions were found to be suspicious. The top 3 of suspicious transitions were all involiving natural grasslands. It has become clear at which location the suspicious transitions take place. The study has strengthened the trust in the use of the nature landuse map of the Netherlands for trend reporting purposes.
References and impact
- Dutch forest as source for CO2 from Dutch Het Nederlandse bos als bron voor CO2
- Dutch TV item on rtl nieuws laat