Glacier development and topographic context

10 páginas, 4 figuras, 2 tablas.-- The definitive version is available at www3.interscience.wiley.comThis paper analyses the topographic context of the remaining glaciated areas in the Maladeta Massif (Central Spanish Pyrenees). These ice-covered surfaces have been incorporated into a geographic information system (GIS) in an attempt at correlating the presence of ice with a range of topographic variables obtained from a digital elevation model. The use of generalized additive models and binary regression tree models enabled us (i) to quantify the spatial variability in the distribution of glaciers attributable to characteristics of the local terrain, (ii) to investigate the interaction between the variables that account for the ice cover distribution and (iii) to map the probability of glacier development. Our results show that although the development of glaciers depends on regional climate conditions, the topographic context is of paramount importance in determining the location, extent, shape and recent evolution of each glacial body. Thus, the joint effect of altitude, exposure to incoming solar radiation, slope and mean curvature is able to explain more than 70 per cent of the observed variance.This study was supported by the following research projects: ‘Hydrologic and erosive processes in Pyrenean catchments, related to land use changes and climate variability’ (PIRIHEROS, REN 2003-08678/HID) and ‘Characterization and modelling of hydrological processes in gauged basins for the prediction of ungauged basins’ (CANOA, CGL 2004-04919-c02-01), both funded by the CICYT, Spanish Ministry of Science and Technology; and ‘Estudio de la dinámica de los glaciares del Pirineo Aragonés’ (H9007- CMA), funded by the Gobierno de Aragón. David Nogués-Bravo is a post-doctorate researcher working on the ALARM project (GEOCE-CT-2003-506675).Peer reviewe