Objectif The objectives of this project are the measurement and the modelling of the local water losses to the atmosphere in Eucalyptus globulus and Pinus Pinaster in central Portugal. Interception losses will be measured during wet periods and transpiration losses during dry canopy periods. The study of soil moisture profile under the 2 aforementioned forest species will also be made. Testing and development of models of interception and transpiration is also one of the objectives of this project. Interception losses will be evaluated using the classical method, based on the continuity equation, measuring gross precipitation, throughfall and stemflow. As in the methods based on this equation, the error in the interception loss will be an accumulation of the errors in the other measured variables. To obtain good results these variables will be measured with fairly high accuracy. Gross precipitation will be sampled at ground level in an opening near the experimental plots. Throughfall will be sampled by a dense network of gauges and each gauge will be randomly relocated within the grid after each measurement. Stemflow will be measured on some trees within the area of the random grid. Aerodynamic resistance for the 2 species investigated will be estimated solving the Penman Monteith equation for periods in which evaporation of intercepted water is known from the measurements previously described. For that an automatic meteorological station will be installed above the canopy of each stand. It will provide measurements of net radiation, air temperature, air humidity, wind speed and wind direction at a reference level above each stand. The relationship between aerodynamic resistance and wind speed above the canopy will also be studied. Canopy storage capacity will be estimated by the method proposed by Leyton, where gross precipitation is compared with net precipitation for all the recorded storms. For a better understanding of the rainfall interception process the Rutter model and the Gash analytical model will be adapted to the case study. To estimate transpiration losses from the pine and eucalyptus stands during dry periods the Penman Monteith equation will be used. Data needed to apply this model will be obtained from the automatic meteorological stations as well as from additional measurements of leaf area index (using a multicone sensor) and stomatal resistance (using a null balance porometer) which will allow estimation of the surface resistance. Complementing the study, leaf water potentials and soil moisture profiles will be followed throughout the year using a pressure chamber and a neutron probe. Champ scientifique engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringsensors Programme(s) FP2-STEP - Two specific research and technological development programmes (EEC) in the field of the environment STEP/EPOCH - STEP -, 1989-1992 Thème(s) Data not available Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur INSTITUTO SUPERIOR DE AGRONOMIA Contribution de l’UE Aucune donnée Adresse Tapada da Ajuda LISBOA Portugal Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée Participants (1) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire NATURAL ENVIRONMENT RESEARCH COUNCIL Royaume-Uni Contribution de l’UE Aucune donnée Adresse Maclean Building, Crowmarsh Gifford OX10 8BB WALLINGFORD Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée
