South Georgia is a highly glacierized island with a range of glacier types including corrie, valley and tidewater ice bodies. Glaciologically, it occupies a strategic location between South America and the Antarctic Peninsula and is potentially an important locality for establishing glacier-climate relationships in the region. Baseline surveys of ice front positions and ice surface profiles have been repeated to determine recent changes in several glacier types. Corrie and small, land-based valley glaciers have continued to thin and recede during the period of study, following an advance during the 1930s. Their behaviour primarily reflects the effects of seasonal temperature variations in controlling net balances, and particularly the climatic warming since 1950. The larger valley and tidewater glaciers display a lagged response and in the 1970s were at their most advanced positions since the Little Ice Age of the 17–19th centuries. However, in the last few years they too have commenced to thin and recede.

Climatic changes could alter the frequency and magnitude of rainfall events and the distribution of rainfall with altitude, with important consequences for management of aquatic ecosystems, water resources and flood risk. This study investigates changes in observed rainfall amounts across a range of altitudes in the Lake District region, northwest England, and spatial and temporal changes to the orographic "rainshadow" effect. Between the 1970s and 1990s there have been marked changes to the seasonality of precipitation, such that winters have become wetter, and increasingly dominated by heavy precipitation events. The intensity of these events has increased most markedly at higherelevation sites. Such changes could hinder recovery of sensitive upland sites from acidification and increase the risk of downstream flooding. An inter-decadal weakening of the region's rainshadow suggests a greater proportion of winter precipitation crosses the high-elevation Lake District dome. This is linked to changes in the frequency and character of wet weather patterns.Key words climate change; Lake District, England; Lamb weather types; rainshadow Variations à long terme des précipitations orographiques: analyse et implications pour des bassins versants d'altitudeRésumé Les changements climatiques pourraient changer la fréquence et la magnitude des événements de précipitation et la distribution des précipitations selon l'altitude, avec des conséquences importantes pour la gestion des écosystèmes aquatiques, des ressources en eau et du risque d'inondation. Ce travail étudie les changements dans les hauteurs de précipitation observées selon une gamme d'altitude dans la région du Lake District, dans le nord-ouest de l'Angleterre, ainsi que les changements spatiaux et temporels dans l'effet orographique de l'ombre pluviométrique. Entre les années 1970 et les années 1990 il y a eu des changements marqués dans la saisonnalité de la précipitation, tendant vers des hivers plus humides et de plus en plus dominés par des événements de forte précipitation. L'intensité de ces événements a augmenté le plus nettement aux lieux les plus élevés. De tels changements pourraient gêner le rétablissement de sites d'altitude sensibles à l'acidification et augmenter le risque d'inondation à l'aval. Un affaiblissement inter-décennal de l'ombre pluviométrique de la région suggère qu'une plus grande proportion de la précipitation hivernale traverse le dôme de haute altitude du Lake District. Ceci est lié aux changements dans la fréquence et dans le caractère des schémas de temps humide.

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