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Mediterranean desertification and land use impacts - Project 2 - Modelling and regionalisation


To develop techniques to extend the physically based and
agricultural systems based models, developed under Medalus I, up
to the regional scale and climatic models down to the regional
scale in preparation for application in the test areas of Project
4 of Medalus II, in order to successfully interface the research
programme with the need for scientifically informed policy
decisions at regional scales.

Sections of the physically based model (mainly the mechanistic
sub-model of vegetation) developed under MEDALUS I will be
refined, and the whole system will then be extended to the
regional scale (up to 5,000 km{2}). Extension of the model to
the regional scale (MEDRUSH) will be through the development of
distributions of land-use and vegetation from remotely sensed
images; the incorporation of topographic-scale terms in storm
precipitation tracks and the integration of plot run-off and
sediment yield up to moderate-sized catchments through an
explicit hydrological model. Distributions of land- use and
vegetation will be based on remotely sensed data across the
Mediterranean zone, empirically relating to Desertification
Response Units (DRUs) to observe and simulate interactivel
patterns of change over time.

The work on remote sensing will concentrate on the use of
multi-date Landsat TM and NOAA AVHRR data for characterising the
temporal and spatial variability of vegetation and land use at a
range of spatial scales (10-1000 km{2}) for field sity and
target catchments across the whole of the Mediterranean zone.

The concept of Desertification Response Units (DRU's) was
developed under Medalus I to link spatial patterns in the field
to aid in understanding the spatial dynamics of desertification
processes. This work will be extended under the current project
to better determine the mechanisms involved in the DRU model
(regeneration and colonisation process of sparse vegetation,
water distribution at different spatial and temporal scales, etc)
and to develop techniques for extending networks of DRU's to the
regional scale with the use of remote sensing measurements.

The SHE model will be used to simulate impacts of environmental
change in the regional scale. Use of the SHE at the various
spatial scales will involve comparisons with the extension of the
MEDALUS model to provide cross-validation of the MEDALUS.

The climate group investigate the implications of the enhanced
greenhouse effect for changes in extreme events, and the
potential impacts of such changes for the agricultural economy of
the field site and target areas. Routine archiving of climate
data will also continue. In addition, the large-scale regional
climate change scenarios developed under MEDALUS I will be
up-dated as information from new GCM runs becomes available. It
is hoped that detailed regional scenarios can be generated for
the MEDALUS II target areas, as suitable data become available.

Appel à propositions

Data not available

Régime de financement

CSC - Cost-sharing contracts


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Contribution de l’UE
Aucune donnée

Participants (8)