To understand the processes which control the seasonal
hydrological budget of the semi-arid Messara Valley of Crete,
especially those which control groundwater levels, and to
identify those processes which may lead to the desertification of
Measurements and models will be used to determine the seasonal
hydrological budget of the Valley and for relating it to
atmospheric conditions, and hence to global climatic change.
The data required to develop and validate an integrated model for
the seasonal hydrological budget of the Valley include daily
rainfall, runoff, and groundwater levels at numerous sites, for
which there are detailed historical records. These data will be
supplemented by measurements taken by local authorities and by
the project teams during the duration of the project.
The hydrological models require potential and actual
evapotranspiration to estimate rainfall losses to the atmosphere.
PET will be estimated from data collected by an automatic weather
station while ET will be estimated at two significant periods of
the Mediterranean hydrological cycle. These correspond to the
end of the dry season (September-October) and the end of the wet
season (April-May). To extend the evapotranspiration estimates
to the whole Valley, satellite data will be used to delineate
land-cover patterns (Landsat and/or SPOT) and to characterise the
surface energy budget (AVHRR).
A limited amount of hydrological and energy budget field work
will be possible in this phase. Soil moisture and groundwater
level monitoring is planned to fill in possible gaps in the
existing data, while energy budget measurements over selected
vegetation will take place during the wet and dry seasons. Field
work to delineate land cover will take place over the project
An integrated hydrological-energy budget model will be developed
comprising a daily rainfall-runoff model, a 2-D groundwater-level
model, and an evapotranspiration model. The integrated model
will be used to examine climatic change effects on the Valley's
water budget based on GCM scenarios for the region.
Call for proposalData not available
Funding SchemeCSC - Cost-sharing contracts
6701 AP Wageningen