Abstract

Glaciated Andean mountains have experienced several decades of shrinkage in their transition to non-glaciated regimes. This study analyses the period of hydrologic transition 1956-2020 in a watershed of the Sierra Nevada del Cocuy (SNC), which is the most extensive, remaining tropical glacier in Colombia. Using ground hydrometeorological data, remote sensing products, a metric of extreme flows regulation, and decadal flow duration curves, the study shows how the combined effect of continuous glacier shrinkage, highly variable precipitation regimes and increasing human extractions have altered the hydrological capacity of the watershed to regulate high, low, and mean flows. The alteration is noticeable since the 2000s, when communities have effectively benefited from the surplus of baseflow provided by the shrinking glacier to the limit, creating an unsustainable dependency with potential restrictions of use in the short run and major implications for water security of humans and the environment in the forthcoming decades.

摘要

冰川化的安第斯山脉在向非冰川化状态过渡的过程中经历了数十年的收缩。本研究分析了 1956-2020 年内华达山脉 (SNC) 流域的水文过渡期，该流域是哥伦比亚现存最广泛的热带冰川。该研究利用地面水文气象数据、遥感产品、极端流量调节指标和年代际流量持续时间曲线，展示了冰川持续收缩、高度可变的降水状况和人类开采量增加的综合影响如何改变了流域的水文容量调节高、低和平均流量。自 2000 年代以来，这种变化是显而易见的，当时社区有效地受益于冰川萎缩至极限提供的过剩基流，