Rock glaciers as water stores in the Bolivian Andes: an assessment of their hydrological importance

Water scarcity is a growing issue for high altitude arid countries like Bolivia, where serious water resource concerns exist because of climate change and population growth. In this study we use a recent Bolivian rock glacier inventory (Rangecroft et al., 2014) to estimate the water equivalent storage of these understudied cryospheric reserves. This paper shows that Bolivian rock glaciers currently store between 11.7 and 137 million cubic meters of water. Rock glacier water equivalents are compared to corresponding ice glacier water equivalent to allow an assessment of the hydrological importance of rock glaciers as water stores in this water scarce region. It can be seen that in the densely glaciated Cordillera Real (15 degrees-16 degrees S) rock glaciers form a small component of mountain water stores; however, along the Cordillera Occidental (17 degrees-22 degrees S), where ice glaciers are absent, rock glaciers are a more important part of the cryospheric water store, suggesting that they could be important for local water management. This is the first time that the water equivalence of the Bolivian rock glacier store has been quantified and is a first step toward assessing the contribution and importance of alternative high altitude water sources.