Article,
Climate or land cover variations: what is driving observed changes in river peak flows? A data-based attribution study
Hydrology and Earth System Sciences, 23 (2): 871-882 (2019)
DOI: https://doi.org/10.5194/hess-23-871-2019
Abstract
<p><strong>Abstract.</strong> Climate change and land cover changes are influencing the
hydrological regime of rivers worldwide. In Flanders (Belgium), the
intensification of the hydrological cycle caused by climate change is
projected to cause more flooding in winters, and land use and land cover changes
could amplify these effects by, for example, making runoff on paved
surfaces faster. The relative importance of both drivers, however, is still
uncertain, and interaction effects between both drivers are not yet well
understood.</p> <p>In order to better understand the hydrological impact of climate variations
and land cover changes, including their interaction effects, we fitted a
statistical model for historical data over 3 decades for 29 catchments in
Flanders. The model is able to explain 60 % of the changes in river peak
flows over time. It was found that catchment characteristics explain up to
18 % of changes in river peak flows, 6 % of changes in climate variability and 8 % of land
cover changes. Steep catchments and catchments with a high proportion
of loamic soils are subject to higher peak flows, and an increase in urban
area of 1 % might cause increases in river peak flows up to 5 %.
Interactions between catchment characteristics, climate variations and land
cover changes explain up to 32 % of the peak-flow changes, where flat
catchments with a low loamic soil content are more sensitive to land cover
changes with respect to peak-flow anomalies. This shows the importance of
including such interaction terms in data-based attribution studies.</p>
