Reconstructing valley landscapes. GIS-analyses of past land use changes in three Flemish river valleys since the late 18th century

Abstract

The restoration of riverine ecosystem services and floodplain landscapes has become an important tool in climate mitigation, however, it is often unclear what landscape a restoration is (or should be) referring to. Little is known moreover, about long-term transitions in historic valley land use or how they echo in contemporary perceptions of floodplain landscapes. Also in densely populated Flanders (in the north of Belgium), where floodplains are quickly losing their natural functions, policymakers are actively in pursuit of climate change adaptation strategies and sustainable valley management. We present the results of a GIS-based reconstruction of historical land use in three Flemish river valleys from 1771 to 2002 and compare them to changes in regional land use. We find that while grasslands initially and to a vast extent covered our selected floodplains, the latter were by the mid-19th century cultivated for agricultural production, in line with a global expansion of arable land and regional demographic growth. Also forest cover in the studied river valleys grew exponentially from the late 19th century, unmatched by regional forest cover. After the Second World War, a denser road network, more area that is built-up and forest plantations visually contributed to valley compartmentalisation and the perception of a closed landscape. Varying soil textures and drainage levels or the (in)ability to manage them properly accounted for different(ly) (timed) land use changes between the studied floodplain areas. Regional changes in historic land use were of lesser importance.