Hydro-meteorological trends in semi-arid north-central Chile (29–32°S): water resources implications for a fragile Andean region

Abstract

Changes in hydro-meteorological historical records are of considerable importance for future planning. This study analyses trends of hydro-climatological indices of annual and seasonal precipitation, temperature and discharge in the “Norte Chico” region of Chile (29–32°S), located in the Central Andes. It addresses how these trends possibly impacted on the water resources in a nival regime, typical for arid mountainous regions. Homogenous records were tested against monotonic trends using the non-parametric rank-based Mann-Kendall test. The results suggested, at a very high confidence level, a strong warming signal trend over recent decades, consistent at the annual and seasonal levels. Furthermore, warmer days are observed in summer, especially at higher elevations. The region also experienced a shift in the rainy season over the last 42 years. However, an increase in precipitation was observed over recent decades, whereas an annual decrease was the general tendency when the whole century was considered. Changes in discharge were not unequivocal and glacier retreat has been compensated for possibly by an increase in snowmelt in recent years. Hence, in an under-studied area, from the hydrological perspective, this work provides some insights for a better understanding of changing hydrological processes in the mid-latitude Andes Cordillera. Editor Z. W. Kundzewicz Citation Souvignet, M., Oyarzún, R., Verbist, K.M.J., Gaese, H. and Heinrich, J., 2012. Hydro-meteorological trends in semi-arid north-central Chile (29–32°S): water resources implications for a fragile Andean region. Hydrological Sciences Journal, 57 (3), 479–495.