Spatially assessing the role of glacier and snowmelt for meeting environmental flow requirements in a high mountain Andean catchment
- 1Institute for Landscape Ecology and Resources Management (ILR), Research Centre for BioSystems, Land Use and Nutrition (iFZ), Justus Liebig University Giessen, Heinrich-Buff Ring 26, 35392 Giessen, Germany
- 2Department of Physical Geography, Utrecht University, Princetonlaan 8a, 3584 CB, Utrecht, Netherlands
- 3Centre for International Development and Environmental Research (ZEU), Justus Liebig University Giessen, Senckenbergstrasse 3, 35390 Giessen, Germany
As climate change continues to alter the dynamics of hydrological flows, quantifying the associated environmental impacts become more and more vital.
Here we present a study focusing on analyzing the spatial and temporal distribution of flow components, particularly the contributions of glacier melt, snowmelt, rainfall-runoff, and groundwater flow to river discharge in the high mountain Santa River catchment. The catchment is located in the Cordillera Blanca of Peru, the region with the largest glacier cover in the tropics, and has an area of 12,279 km², an average discharge of 133 m3/s, and average annual precipitation of 750 mm.
We used the spatially distributed cryospheric-hydrological model SPHY, forced with W5E5 meteorological data (1979 - 2019) to simulate daily spatial discharge components. Additional static inputs such as a digital elevation model, land use maps, soil hydraulic properties, and glacier extent, thickness, and debris cover were collected from freely available remote sensing-based datasets.
The model runs at a spatial resolution of 500 x 500 meters with daily time steps. Data from 1995 to 1997 were used to spin up the model. Calibration (1998 - 2001) and validation (1998 - 2018) were performed through the comparisons of simulated and observed discharge. The model's performance was evaluated by the percent bias (1.5%; -7.2%), Nash-Sutcliffe efficiency (0.81; 0.65), and R2 (0.82; 0.68). With the best runs, the complete 41 years were simulated.
Further analysis evaluates how glacier melt and snowmelt compensate the discharge amount in dry periods to meet environmental flow requirements and the derived environmental services chain.
The overall outcome of this assessment will define spatially distributed compensated zones, ensuring an informed management of glacier covered watersheds, as well as open up new horizons to better understand, and mitigate, the impacts of climate change.
How to cite: Marinelli, B., Lutz, A., Breuer, L., Weeser, B., and Correa, A.: Spatially assessing the role of glacier and snowmelt for meeting environmental flow requirements in a high mountain Andean catchment, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8477, https://doi.org/10.5194/egusphere-egu22-8477, 2022.
