Hazard mitigation of glacial lake outburst floods in the Cordillera Blanca (Peru): the effectiveness of remedial works

Almost 40 glacial lakes have been remediated in the Cordillera Blanca since the 1940s by implementing different types of structural measures to prevent (mitigate) glacial lake outburst floods. These are (1) open cuts; (2) artificial dams; (3) tunnels; and their combinations. The first part of the paper provides an overview and description of the implemented remedial works. In the second part, the effectiveness of these remedial works is evaluated on the basis of a comparison of the quantified susceptibility of nine selected lakes to outburst floods before and after remediation. Our investigation showed that different types of remedial works have different impacts on the susceptibility of a given lake to outburst floods and are effective for different scenarios (causes and subsequent mechanisms) of outburst floods. Hazard management implications in the framework of risk management and ongoing geo‐environmental change are also discussed.