Geographical Information and Climatology for Hydrology - Geographical Information and Climatology - page 225

spatial structure of the rainfall with the density of the network that is required. As
far as the networks of rain gauges are concerned it is possible to create different
networks with different densities [CHA 00].
The information that is produced by the rain gauges provides information on
temporal distance, but does not always provide accurate information on the spatial
distribution of rainfall. For the last 25 years we have been working towards the
following goal: it is necessary to include geographical information within the
interpolation process that is applied to rainfall. Even if this geographical information
were to be progressively adopted when it comes to plotting the parameters of
precipitation on a map (median averages, values recorded over a period of 10 years,
gradex, etc), this would not be the case for plotting the isohyetal lines on a map that
provides information on a particular period of rainfall. Studies carried out in the
French regions of Corsica and Provence-Alpes-Côte d'Azur (PACA) and in Algeria
have shown that whenever geographical information is used in the interpolation
process that is applied to rainfall, more information is known about the drainage
basin. Using geographical information in conjunction with the interpolation process
is only applied to certain parameters of hydrological models that are specific to the
drainage basins. It is no longer used to correct values of the rainfall.
Initially, the geostatistical approach used to study rainfall seems to be rather
complex and to have little to do with the physical make up of the rainfall. The
geostatistical approach is, however, a particularly constructive approach in the sense
that all hypotheses need to be clearly formulated, all uncertainties need to be
quantified and at the end a coherent spatio-temporal model should be created.
7.5. Bibliography
[ALE 96] A LEXANDRE C., “Conception et dimenssionnement des barrages en terre de
Mauritanie”, Mémoire d'ingénieur, Ecole nationale du génie de l'eau et de
l'environnement de Strasbourg, 1996.
[ASS 00] A SSABA M., L ABORDE J.P., “L'intérêt de la prise en compte du relief dans
l'estimation des pluies mensuelles: le cas de la Corse”, International Assocation for
Climatology Publications , vol. 13, pp. 149-157, 2000.
[ASS 04] A SSABA M., “La connaissance des pluies mensuelles au service de la modélisation
hydrologique des apports mensuels en eau de surface”, PhD thesis, University of Nice -
Sophia Antipolis, 2004.
[ASS 06] A SSABA M., L ABORDE J.P., A CHOUR F., “Global and distributed modelling of runoff
in northern Algeria”, 7 th International Conference on Hydroinformatics , Nice, 2006, pp.
1551-1558.
[BEN 87] B ENICHOU P. , L E B RETON O., “Prise en compte de la topographie pour la
cartographie des champs pluviométriques statistiques”, Météorologie , vol. 19, pp. 23-44,
1987.