ALBERT

Description: Climate change and retreating mountain glaciers will have a profound impact on the headwaters of river systems in High Mountain Asia. Robust estimates of future water availability are essential to mitigate local impacts. While various glacio-hydrological modeling tools and high quality input datasets are available, most are not ready for effective application in less developed countries that will be severely affected by climate change. Very few tools provide the low access and cost needed to engage water management professionals and stakeholders in these regions, especially at the local scale. Initiated in a Kyrgyz-German research project, we have compiled an open-source toolset for modeling glacier evolution and water resources in glacierized catchments (MATILDA), combining open-access datasets (e.g. climate, Terrain, and glacier data) and well-established modeling routines (temperature index model, Δh glacier rescaling, HBV model) with useful tools (e.g. Google Earth Engine, PySheds, SPOTPY, plotly). MATILDA is designed as an easy-to-use online workflow in Python, documented in Jupyter notebooks, from public data acquisition and preprocessing, through multi-objective calibration and parameter optimization, to analysis and visualization. It allows users to generate scenario-based hydrologic projections and analyze runoff contribution trends requiring only runoff observations as input. In the associated study, we showcase MATILDA on two glacierized catchments in the Kyrgyz Tien Shan and evaluate different reanalysis products as forcing data. Furthermore, we test two possible calibration approaches and investigate parameter sensitivity and model uncertainty. We then discuss limitations and possible improvements, and look forward to further applications in Kyrgyzstan and a new project in Uzbekistan.