Review papers
Refsgaard et al. (2022) review
developments in hydrological modelling of catchment response over the
past 60 years. Several important advancements have driven these
developments. Scientists now have much better understanding of
hydrological processes, leading to their improved representation in
models. Another advancement is improved availability of data – more
variables, at higher frequency, and observed at more places. Multi-band
remote sensing data at higher spatial and temporal resolutions and
algorithms to compute data of missing variables at the required scales
by using the satellite data have added to the richness of databases.
Scientists also have access to increasing computational power, enabling
them to use larger volumes of data and an ensemble of models. However,
it has also been realized that such developments have not necessarily
resulted in better modelling approaches. In addition, Refsgaard et al.
(2022) illustrate the importance of spatial resolution and improved data
resolutions in a case study, where a model setup was run at 100 m and
500 m resolutions. While the two models perform equally well for
simulation of catchment discharge, the underlying processes such as
streamflow partitioning differ significantly.
The paper by Wheater et al. (2022) reviews recent developments and
discusses scientific and technical challenges of large-scale cold region
hydrological modelling with a focus on the Canadian community
hydrological land surface scheme MESH (Modélisation Environmental
Communautaire – Surface and Hydrology). Cold regions are crucial for a
large part of the global population and face major and rapid changes due
to global warming. At the same time the hydrology is particularly
complex, because it includes cold region processes such as permafrost,
frozen soil, snow and glaciers, where hydrological processes often are
controlled by phase change energetics. Modelling of large river basins
in cold regions are often subject to relatively sparse data coverage and
application of remote sensing data has recently shown important
benefits. A key conclusion is that cold region hydrology is particularly
sensitive to temperature changes and that even small biases in forcing
data from global climate models pose large challenges. Wheater et al.
(2022) furthermore conclude that the understanding and description of
hydrological processes related to permafrost and frozen soil as well as
certain glacier processes poses significant challenges and scopes for
improvement.