Current water resources in Europe and Africa - Matching water supply and water demand

An assessment for Europe on available water resources and a comparison with water
demands from various economic sectors shows that freshwater availability over the
European continent varies significantly. Large areas in Spain and Eastern Europe have
on average less than 200 mm generated freshwater per year. At the same time, in parts
of those areas annual water demand from the various sectors is equal or even larger than
the freshwater generation. However, estimating water scarcity is not a straightforward
exercise, since important parts of the ‘puzzle’ are missing, such as inter-riverbasin water
transfers, detailed information on various storages in lakes and reservoirs, as well as the
use of deep/fossil groundwater. Therefore, estimating water scarcity still includes many
uncertainties, and the estimation made here needs further improvement.
In addition, although data needed for water resources assessment do exist in Europe, the
access to these data to make a pan-European overview could still be improved - the
public availability of observed river flows is still a particular concern. The availability
of meteorological observations, together with increased availability of satellite
observations, has greatly improved already.
An assessment of the African continent reveals large areas with less than 200 mm
freshwater generation per year. Areas with freshwater generation larger than 200 mm
are situated in Morocco, equatorial Africa, Southwest Ethiopia, Eastern South-Africa
and Madagascar. Estimating water scarcity is again a challenging exercise. First of all,
the most recent pan-African data on water abstractions date from the year 2000, which
needs improvement. Next, as in Europe, information on large inter-riverbasin water
transfers is not available.
There are many future research challenges, knowledge gaps, and data gaps in the field
of water resources estimation. The lack of available observed river flow data for Africa,
for example, creates a major bottleneck in calibrating and verifying hydrological models
for this continent. Satellite data provide improved meteorological data for Africa, but
data on water abstractions need to be updated more frequently. In general, information
on long-distance water transfers - intra riverbasin, inter-riverbasin, or cross-border - is
largely unavailable at continental and global level.