Rainfall interception in laurel forest in the Canary Islands

Abstract

Throughfall, stemflow, incident rainfall and meteorological variables necessary for estimation of potential evaporation were monitored over the period December 1994 to December 1995 in a laurel forest plot on Tenerife Canary Islands). Observed interception losses were compared with those predicted using the Rutter model and the Gash model. All approaches predicted interception losses reasonably, the best prediction was obtained with the Gash model (only 2% over-estimation of the measured total for the study period), with the method of estimation of r a having little effect. Application of the Gash model with 30 years’ rainfall data (1967–1997) from the study area indicated a mean interception loss of 30% of rainfall, with a maximum of 41% in 1995. The marked differences between our results and those of previous studies are attributable to both canopy characteristics (notably the high canopy storage capacity, 2.45 mm) and climatic characteristics (notably the low mean evaporation rate during post-saturation rainfall, 0.028 mm h −1, due to the presence of orographic cloud during rainfall).