TDR soil moisture measurements at the Lago Maggiore MAP target area: Preliminary results

Surface moisture was measured at selected sites in the L ago Maggiore (Ital y) target area before and during Mesoscale Alpine Programme (MAP) Special O bserving Period (SOP). Additional soil moisture measurements were performed contemporaneously with remotely sensed microwave measurements carried out by another MAP team. The soil moisture conditions influence the runoff prod uced during heavy precipitation events but long records of soil moisture me asurements, like that presented here, are difficult to obtain. This data se t, available at MAP Data Center, may be useful to improve real time flood f orecasting and Numerical Weather Prediction models. TheOsservatorio Geofisi co (University of Modena and Reggio Emilia) team collected volumetric water content measurements by the Time Domain Reflectometry (TDR) technique. The TDB system was equipped with multiplexer so that 14 buriable probes, insta lled at different depths, were automatically scanned at four hour time inte rvals and the daily soil moisture profiles were recorded. The data have bee n collected from the end of March 1999 up to the end of MAP-SOP (November 1 5, 1999), During this period, the first 70 cm of soil were monitored; the m inimum of the soil moisture was 17.7 %; the maximum of the soil moisture wa s 56.0 %. The data allow also investigation of the soil behaviour after hea vy precipitation events (e.g. the one happened during the MAP Intensive Obs ervation Period (IOP) 02) depending on its moisture condition before the pr ecipitation. Finally, from the soil water content profile, the cumulative e vaporation is computed on the basis of a mass balance, when drainage is sup posed to be ceased and no horizontal flux is present. (C) 2001 Elsevier Sci ence Ltd, All rights reserved.