RESUMEN
The Mediterranean area is historically characterized by high human pressure on water resources. Today, while climate is projected to be modified in the future, through precipitation decrease and temperature increase, that jointly and non-linearly may affect runoff, concerns about water availability are increasing. For these reasons, quantitative assessment of future modifications in the mean annual water availability are important; likewise, the description of the future interannual variability of some hydrological components such as runoff and evapotranspiration are highly wished for water management and ecosystems dynamics analyses. This study investigates at basin spatial scale future runoff and evapotranspiration, exploring their probability density functions and their interdependence as functions of climatic changes. In order to do that, a parsimonious conceptual lumped model is here used. The model is forced by different future climate scenarios, generated through a weather generator based on a stochastic downscaling of an ensemble of General Circulation Models (GCMs) realizations. The use of the adopted hydrological model, under reliable stochastic future climate scenarios, allows to project future values of evapotranspiration and runoff in a probabilistic framework and, at the same time, the evaluation of their bivariate frequency distributions for changes through the Multivariate Kernel Density Estimation method. As a case study, a benchmark Mediterranean watershed has been proposed (Imera Meridionale, Italy). Results suggest a radical shift and shape modification of the annual runoff and evapotranspiration probability density functions. Possible implications and impacts on water resources management are here addressed and discussed.
RESUMEN
BACKGROUND: The significance of ambulatory venous pressure measurement in the diagnosis of chronic venous insufficiency of the lower limbs is evaluated. METHODS: 190 limbs of 120 outpatients were investigated from 1991 through 1997; the study was performed whenever clinical and ultrasound evaluation did not allow to establish the diagnosis of "simple varices". The technique standardized according to Nicolaides was followed. RESULTS AND CONCLUSIONS: The results of the study confirm the importance of ambulatory venous pressure measurement in the differential diagnosis of chronic venous hypertension of the lower limbs, especially when caused by vein compression, as well as in the follow-up of these patients when submitted to surgical treatment.