Towards a Mediterranean GEWEX
361
remote sensing data from the surface and space have been involved. At some places
precipitation radar is being operated. This information, if synthesised, would render
new insights into the Mediterranean water cycle. Many questions nevertheless
remain open to solve the problem of the future water resources. The role of the sea
in the context with extreme events has more carefully to be studied (e.g. is it correct
to say, more frequent and intensive extreme precipitation events are caused by the
increasing SST?). Do models represent atmospheric water vapour concentrations
and regional precipitation accurately enough (what at all is their accuracy?). Little
is known about the regional development of the soil water content and the ground
water level. Are the available data about water budgets consistent with each other?
Is the Mediterranean water cycle accelerating?
Beside these basic problems this sector also includes a number of application
directed questions such as:
Are the fresh water resources more endangered by precipitation changes or by
exploitation? This relates to the problem of the retention capacity of soils,
aquifers and artificial storage for winter/spring rains which are needed in
summer.
Is the sea-atmosphere interaction changing? What is the function of the sea with
its temperature stabilising function and its high potential evaporation rates in
summer which may be reduced by an increasing capacity of the atmosphere to
take up water vapour with increasing temperature? Model simulations indicate
even regional negative water vapour fluxes at high air temperatures and the
question is, whether these results can be validated by measurements.
• To what degree is it possible to enhance the storage capacity for water needed in
drought situations without creating other problems?
If a system undisturbed by man is compared with one that uses water for
increasing the economy (irrigation, tourism, industry), what are the changes in
the water flows and how does the consumption of water matter in the budget?
Much independent information has to be brought together to deal with these
problems and with the improvement of predictive tools. A first inventory should be
undertaken how the mosaic of information pieces can be amalgamated and which
gaps exist that must be closed by additional measurements for which Anchor
Stations (see item 5) could play an important role. This may then lead to a GEWEXtype experiment or a decade of research into the Mediterranean water cycle (Fig.3).
The water cycle problem outreaches to atmospheric chemistry, pollution and
geo-biochemical cycles. Since a number of chemical processes are intimately
connected with hydrological processes a close cooperation between these two
communities is imperative. Certain processes have jointly to be studied in depth
(such as the relationship between carbon and water fluxes from the biosphere, soil
transformation due to drought periods, fires and application of new agricultural
techniques) and data connecting ground based and satellite measurements have to
be produced. Obvious is also the link to the marine community.
Notwithstanding that a narrower network of hydro meteorological stations should
be and may be established, an integration over the whole basin to assess the water
361
remote sensing data from the surface and space have been involved. At some places
precipitation radar is being operated. This information, if synthesised, would render
new insights into the Mediterranean water cycle. Many questions nevertheless
remain open to solve the problem of the future water resources. The role of the sea
in the context with extreme events has more carefully to be studied (e.g. is it correct
to say, more frequent and intensive extreme precipitation events are caused by the
increasing SST?). Do models represent atmospheric water vapour concentrations
and regional precipitation accurately enough (what at all is their accuracy?). Little
is known about the regional development of the soil water content and the ground
water level. Are the available data about water budgets consistent with each other?
Is the Mediterranean water cycle accelerating?
Beside these basic problems this sector also includes a number of application
directed questions such as:
Are the fresh water resources more endangered by precipitation changes or by
exploitation? This relates to the problem of the retention capacity of soils,
aquifers and artificial storage for winter/spring rains which are needed in
summer.
Is the sea-atmosphere interaction changing? What is the function of the sea with
its temperature stabilising function and its high potential evaporation rates in
summer which may be reduced by an increasing capacity of the atmosphere to
take up water vapour with increasing temperature? Model simulations indicate
even regional negative water vapour fluxes at high air temperatures and the
question is, whether these results can be validated by measurements.
• To what degree is it possible to enhance the storage capacity for water needed in
drought situations without creating other problems?
If a system undisturbed by man is compared with one that uses water for
increasing the economy (irrigation, tourism, industry), what are the changes in
the water flows and how does the consumption of water matter in the budget?
Much independent information has to be brought together to deal with these
problems and with the improvement of predictive tools. A first inventory should be
undertaken how the mosaic of information pieces can be amalgamated and which
gaps exist that must be closed by additional measurements for which Anchor
Stations (see item 5) could play an important role. This may then lead to a GEWEXtype experiment or a decade of research into the Mediterranean water cycle (Fig.3).
The water cycle problem outreaches to atmospheric chemistry, pollution and
geo-biochemical cycles. Since a number of chemical processes are intimately
connected with hydrological processes a close cooperation between these two
communities is imperative. Certain processes have jointly to be studied in depth
(such as the relationship between carbon and water fluxes from the biosphere, soil
transformation due to drought periods, fires and application of new agricultural
techniques) and data connecting ground based and satellite measurements have to
be produced. Obvious is also the link to the marine community.
Notwithstanding that a narrower network of hydro meteorological stations should
be and may be established, an integration over the whole basin to assess the water