Map shows floodplain types and floodplain condition in terms of floodplain extent (habitat loss), structure degradation and processes alteration on a European scale. Data are presented on two levels: country (less detailed scales) and floodplain subcatchment (more detailed scales).

The datasets available include a Copernicus riparian zone dataset, modelled hydrological parameters, and results from the ‘Free-Flowing Rivers’ database.

Floodplain types: The development of a European floodplain typology follows an ecological approach based on environmental factors like altitude and slope, which are known to govern floodplain habitats and biota but not affected by human alterations. Several environmental factors were selected a priori according to their relevance and data availability at European scales. A cluster analysis was used to identify the most important environmental factors (= typology factors) to distinguish between seven ecological floodplain types. Type 1 ‘Very flat lowland floodplains’ and Type 2 ‘Flat lowland floodplains’ cover most parts of the European lowlands, while Type 3 ‘Mid-altitude high run-off floodplains’ and Type 4 ‘Mid-altitude low run-off floodplains’ are located in the hilly regions – with Type 3 mostly located in hilly areas exposed to higher precipitations, and Type 4 located in the Mediterranean and eastern parts of the continent. The Type 5 ‘Mid-altitude plateau floodplains’ are predominantly situated in the flat uplands of Spain and Turkey, but also in parts of the Scandinavian Mountains. Type 6 ‘Highland floodplains’ is distributed across the Alps and Pyrenees, while Type 7 ‘Nordic lowland floodplains’ is limited to Scandinavia and parts of the Baltic countries.

Floodplain condition: the assessment of floodplain condition is done separately for the three modules ‘extent’, ‘structures’ and ‘processes’. The indicator for the assessment of floodplain extent quantifies the loss of floodplain type-specific habitats. The assessment of floodplain structures includes two indicators: (1) the land use pressure based on land use data as a proxy for anthropogenic changes of floodplain forms and topography and (2) the presence and abundance of large distinct natural floodplain features such as oxbow lakes, bars and dunes and wetlands. They are compared to floodplain type-specific natural reference conditions. The assessment module of floodplain processes is evaluated using three indicators: (1) the ‘base flow index alteration’ approximates the human modification of base flow and groundwater conditions in the floodplain as an indicator of altered hydrodynamics, (2) the ‘degree of flow regulation index’ relates to a change in channel- and floodplain-forming river discharges as an indicator of altered morpho-dynamics, and (3) the ‘sediment trapping index’ relates to the amount of sediment retention by dams in the catchment upstream, thus quantifying the alteration of the floodplain sediment dynamics. Indicators were assessed against a standard of least disturbed conditions for each of the three modules and categorized into three classes according to the degree of degradation: 1 - no to moderate degradation, 2 - substantial degradation and 3 - severe degradation,.

Map shows floodplain types and floodplain condition in terms of floodplain extent (habitat loss), structure degradation and processes alteration on a European scale. Data are presented on two levels: country (less detailed scales) and floodplain subcatchment (more detailed scales).

The datasets available include a Copernicus riparian zone dataset, modelled hydrological parameters, and results from the ‘Free-Flowing Rivers’ database.

Floodplain types: The development of a European floodplain typology follows an ecological approach based on environmental factors like altitude and slope, which are known to govern floodplain habitats and biota but not affected by human alterations. Several environmental factors were selected a priori according to their relevance and data availability at European scales. A cluster analysis was used to identify the most important environmental factors (= typology factors) to distinguish between seven ecological floodplain types. Type 1 ‘Very flat lowland floodplains’ and Type 2 ‘Flat lowland floodplains’ cover most parts of the European lowlands, while Type 3 ‘Mid-altitude high run-off floodplains’ and Type 4 ‘Mid-altitude low run-off floodplains’ are located in the hilly regions – with Type 3 mostly located in hilly areas exposed to higher precipitations, and Type 4 located in the Mediterranean and eastern parts of the continent. The Type 5 ‘Mid-altitude plateau floodplains’ are predominantly situated in the flat uplands of Spain and Turkey, but also in parts of the Scandinavian Mountains. Type 6 ‘Highland floodplains’ is distributed across the Alps and Pyrenees, while Type 7 ‘Nordic lowland floodplains’ is limited to Scandinavia and parts of the Baltic countries.

Floodplain condition: the assessment of floodplain condition is done separately for the three modules ‘extent’, ‘structures’ and ‘processes’. The indicator for the assessment of floodplain extent quantifies the loss of floodplain type-specific habitats. The assessment of floodplain structures includes two indicators: (1) the land use pressure based on land use data as a proxy for anthropogenic changes of floodplain forms and topography and (2) the presence and abundance of large distinct natural floodplain features such as oxbow lakes, bars and dunes and wetlands. They are compared to floodplain type-specific natural reference conditions. The assessment module of floodplain processes is evaluated using three indicators: (1) the ‘base flow index alteration’ approximates the human modification of base flow and groundwater conditions in the floodplain as an indicator of altered hydrodynamics, (2) the ‘degree of flow regulation index’ relates to a change in channel- and floodplain-forming river discharges as an indicator of altered morpho-dynamics, and (3) the ‘sediment trapping index’ relates to the amount of sediment retention by dams in the catchment upstream, thus quantifying the alteration of the floodplain sediment dynamics. Indicators were assessed against a standard of least disturbed conditions for each of the three modules and categorized into three classes according to the degree of degradation: 1 - no to moderate degradation, 2 - substantial degradation and 3 - severe degradation,.