Assessing Climate Change Impacts on Glacierized Catchments in Central Asia Using an Open Source Toolkit

The impacts of climate change and the retreat of mountain glaciers will significantly affect the headwaters of high mountain river systems. Accurate predictions of future water availability are essential to mitigate local impacts. Despite the availability of various glacio-hydrological modeling tools and high-quality input datasets, their effective application in less developed countries facing severe climate change impacts remains limited. Accessible and cost-effective tools are particularly scarce, hindering engagement with water management stakeholders, especially at the local level.

We present MATILDA, an open-source toolkit for glacierized catchments that allows users to acquire and process public data, apply well-established glacio-hydrological modeling routines, and estimate climate change impacts on the catchment of their choice. The workflow integrates Google Earth Engine, several state-of-the-art online data sources, and calibration algorithms. Published as a Jupyter book, it can be executed in an online Python environment, allowing users to generate scenario-based hydrological projections and analyze trends in runoff contributions, requiring only runoff observations.

The workflow is outlined and discussed in terms of practical application, sensitivity and uncertainty, limitations, and possible improvements. With a view to two regional studies in the Tian Shan Mountains, we evaluate MATILDA’s practical potential to support water management decisions in high mountain areas. The first study assesses the impacts of glacier change on lake levels and local agriculture in the endorheic Issyk-Kul basin in Kyrgyzstan. The second study focuses on the Chirchik River Basin in Uzbekistan and it's crucial role for hydropower production and fresh water supply for the Tashkent metropolitan area.