Early Warning

Kyrgyz Republic

16 February 2026

Originating high in the Tien Shan mountains, the Ala-Archa River flows through Ala-Archa National Park before reaching Bishkek, Kyrgyz Republic’s capital. The park was established to protect the unique wildlife of the Northern Tien Shan and today is one of the country’s most popular destinations for hiking and tourism.

The valley is also among the most debris-flow-prone areas in the region. Outbursts from glacial lakes such as Aksai and Teztor have repeatedly triggered destructive debris flows. The most recent major event, recorded in 2024, destroyed more than 25 houses and caused one fatality.

Against this backdrop, a new scientific article published in «Natural Hazards and Earth System Sciences» evaluates how different disaster risk reduction measures can reduce the impacts of glacial lake outburst floods (GLOFs) and debris flows using Ala-Archa National Park as a case study. Utilizing numerical mass movement models, the study assessed three measures: the artificial lowering of lake levels, a deflection dam, and a retention basin. It presents a comparison of the impact of such measures on the exposure of people and infrastructure to the risk of GLOFs and debris flows.

The study, led by Laura Niggli and co-authored by scientists from the University of Zurich, the Central Asian Institute for Applied Geosciences (CAIAG) and the University of Central Asia (UCA), was conducted within the framework of the GLOFCA project. Funded by the Adaptation Fund and implemented by the UNESCO Regional Office in Almaty in partnership with the University of Zurich, the project supports regional efforts to reduce vulnerability to GLOFs across Central Asia.

The installation of GLOF Early Warning Systems is a key component of the GLOFCA project. The findings of this study provide a quantitative basis for evaluating structural measures that can complement Early Warning Systems and strengthen overall risk reduction strategies. The results show that although artificial lowering of lake levels offers the best cost-to-benefit ratio, it is important to also consider the relatively high maintenance costs of such measures.

Holger Frey from the University of Zurich, co-author of the study, emphasises that “The most effective, cheapest and most sustainable approach to disaster risk management is still long-term spatial planning, based on systematic hazard maps.”

The link to the study: https://nhess.copernicus.org/articles/26/733/2026/