Using air photographs to detect geomorphological and riparian vegetation changes in a streamflow regulated river. The case of Guadarrama river (Central Spain) - EUFRASIA AGUIRRE YEVES; CARRERO DIEZ, LETICIA; GARCIA DE JALON LASTRA, DIEGO M; MERINO DE MIGUEL, SILVIA; Marchamalo Sacristán, Miguel (Geophysical Research Abstracts, Vol. 11, Egu2009-12653, 2009, 2009)