Mapping glacier lakes in Peru

One consequence of current and likely future melting of high mountain glaciers is the development of glacial lakes. Their evolution over time has implications for future water supplies in arid mountains and for the timing and magnitude of glacier hazards, such as Glacial Lake Outburst Floods (GLOFs).

GLOF initiation depends on how lakes are connected to the glacial system, resulting from myriad processes such as the destabilisation of moraine dams and glacier front calving. To better understand these processes, we have undertaken an inventory of all glacier lakes in the Cordillera Blanca of Peru for 2019. We used manual digitisation from Landsat RGB at 30m resolution and have recorded the type of lake dam and its connection with surrounding glaciers and mountain slopes. We have also obtained lake inventories from INIAGEM (Instituto Nacional de Investigación en Glaciares y Ecosistemas de Montaña; 2016) and ANA (Autoridad Nacional del Agua; 2018), and have created an automatic inventory using the Normalised Difference Water Index and Normalised Difference Snow Index in Google Earth Engine. In this presentation we compare these different inventories and discuss both the methods and effectiveness of each for understanding GLOF hazards in the Peruvian Andes.