este artículo contiene 13 páginas, 7 figuras y 3 tablasThis paper analyses the spatial and temporal variability of the hydrological response in a small Mediterranean catchment (Cal
Rod´o). The first part of the analysis focuses on the rainfall–runoff relationship at seasonal and monthly scale, using an 8-year
data set. Then, using storm-flow volume and coefficient, the temporal variability of the rainfall–runoff relationship and its
relationship with several hydrological variables are analysed at the event scale from hydrographs observed over a 3-year period.
Finally, the spatial non-linearity of the hydrological response is examined by comparing the Cal Rod´o hydrological response
with the Can Vila sub-catchment response at the event scale. Results show that, on a seasonal and monthly scale, there is no
simple relationship between rainfall and runoff depths, and that evapotranspiration is a factor that introduced some non-linearity
in the rainfall–runoff relationship. The analysis of monthly values also reveals the existence of a threshold in the relationship
between rainfall and runoff depths, denoting a more contrasted hydrological response than the one usually observed in humid
catchments. At the event scale, the storm-flow coefficient has a clear seasonal pattern with an alternance between a wet period,
when the catchment is hydrologically responsive, and a dry summer period, when the catchment is much less reactive to any
rainfall. The relationship between the storm-flow coefficient and rainfall depth, rainfall maximum intensity and base-flow shows
that observed correlations are the same as those observed for humid conditions, even if correlation coefficients are notably
lower. Comparison with the Can Vila sub-catchment highlights the spatial heterogeneity of the rainfall-runoff relationship
at the small catchment scale. Although interpretation in terms of runoff processes remains delicate, heterogeneities between
the two catchments seem to be related to changes in the ratio between infiltration excess and saturation processes in runoff
formation.PIRIHEROS (REN2003-08678/HID) and CANOA
(CGL2004-04919-C02-01) projects funded by the Spanish
Government, and the TEMPQSIM (EVK1-CT-2002-
00112) project funded by the European Commission.Peer reviewe