The retention ability of the agricultural landscape in the emergency planning zone of the Temelín nuclear power plant and its changes since the 19th century

Drainage and loss of wetland sites is a major problem of the agricultural landscape, as it reduces the landscape’s ability to retain water, nutrients, matter, and minimize erosion. With this in mind, the issue of the ability of wet sites to retain radionuclides and contaminated water in the case of a radiation accident was studied. In 2013, field research examined the occurrence of wetland retention sites in the emergency planning zone (EPZ) of the Temelín nuclear power plant (NPP; Czech Republic). As data sources, wetland biotopes (European network Natura 2000) were considered; in addition, retention features were field mapped, i.e. landscape elements of a wetland nature not normally considered nationally significant for conservation. Within the emergency zone, 2854.7ha of wetland biotopes were registered and 318.9ha retention features mapped. Density of retention sites (inha/km2) per cadastre (local administrative units) was used to represent their spatial distribution within the zone. For an assessment of possible revitalization measures, leading to an increase in the landscape’s retention ability, spatial changes in the area of retention sites between 2013 and the mid-19th century, a period before extensive drainage of landscape occurred and a simplification of its structure, were mapped. Historic land maps (The Imperial Obligatory Imprints of the Stable Cadastre) were used as a basis of information on the occurrence and area of fens and wet meadows (4771.5ha).For spatial comparisons of drained and undrained landscape in the past and present, the density of retention sites per cadastre was calculated. In the mid-19th century, 80% of cadastres had a density of retention sites exceeded 5ha/km2; in 2013 only 40% of cadastres achieved this. In the most part, drained areas of the zone belong to the central part (around the power plant), as well as the EPZ’s eastern and south-eastern regions. From the density maps of retention sites, as well as from the stable cadastre imprints, it is possible to identify areas and retention features suitable for wetland restoration, thus leading to an increase in the retention capacity of the landscape in terms of water and radionuclide retention. Suggestions as to how to restore and turn retention features into semi-natural wetlands, as well as integrating small wetlands into an agriculture landscape are outlined.