4 th ESA CHRIS PROBA Workshop ESA-ESRIN, Frascati, 19-21 September 2006 Semi-arid Wetlands: Assessment of their Degradation Status and Monitoring by Multi-Sensor Remote Sensing Thomas Schmid 1 , Jose Gumuzzio 2 , Magaly Koch 3 and Paul Mather 4 1 CIEMAT, Av. Complutense 22, 28040, Madrid, Spain. 2 Autonomous University of Madrid, Science Faculty, Madrid, Spain. 3 Centre for Remote Sensing, Boston University, Boston, MA, USA. 4 School of Geography, The University of Nottingham, UK. thomas.schmid@ciemat.es Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas Boston University