Furture Projection of Glacier Variation of the Tropical Huayna Potosi West Glacier with Mass Balance and Melt Model

Abstract

 Meltwater is one of the valuable water resources in LaPaz and ElAlto, Bolivia. We conducted simulations of glacier variation of Huayna Potosi West Glacier, Bolivia (16ºS) under the current climate condition and three types of global warming conditions. The simulation is carried out for thirty years. Mass balance and glacial melt were estimated for each 50m elevation zone with Enhanced Temperature Index (ETI) model. Four type of meteorological dataset for the input to ETI model are produced; one assume current climate condition based on observation and the other three assume temperature rise ratio of 0.024, 0.034 and 0.044°C/year derived from general circulation models.
 Simulation under the current climate condition shows that glacial area and meltwater decrease to 4% and 52% of present by the end of next three decades. Accumulation and abluation area reach equilibrium condition by next one decade. The other simulations under different temperature rise also show that glacier does not disappear in the next three decades although the response of glacier shrinking to climate change becomes high with temperature rise. Glacial area decrease by 21-44% of present by the end of next three decades. Annual meltwater is 12% increase to 39% reduction. There are large uncetainties of glacier metl for 30years due to high altitudinal distribution of glacieal area around Equilibriun-Line Altitude.