L'Hôte Yann auteur aut IRD Chevallier Pierre auteur aut IRD Coudrain Anne auteur aut IRD Lejeune Y. auteur aut IRD Etchevers P. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Determining the precipitation phase-rain or snow-is an important factor in modelling discharge in mountainous basins. In a study carried out in the outer tropical Andes Cordillera of Bolivia, half-hourly determination of precipitation phase was obtained by applying a suitable expert system, taking I I meteorological parameters into consideration that are measured over 21 months at an altitude close to 4800 m. Straightforward relationships between the determined precipitation phase and observed air temperature were analysed in histograms that contain percentage occurrences of snowfall, rainfall and mixed precipitation events for 0.5 degrees C air temperature increments. The graph shows a nearly identical distribution of percentage occurrences of snowfall in the Andes to that on a 1600-m high site in the Swiss Alps. This result suggests that, for hydrological modelling purposes in the outer tropical Andes, the same rain/snow threshold temperature as in the compared Swiss site can be applied. specialized air temperature Alps Andes Bolivia hydrological modelling meteorological data precipitation phase Switzerland 062 50 6 989-997 2005 0262-6667 https://www.documentation.ird.fr/hor/fdi:010041223 0262-6667 [F B010041223] https://www.documentation.ird.fr/hor/fdi:010041223 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2024-12/010041223.pdf IRD - Base Horizon / Pleins textes 2006-03-30 2024-12-18 fdi:010041223 fre