University of Arizona Researcher Explores the Link between Cattle Grazing and Flooding

June 25, 2026

By Bella Chin, The Cambridge School Student and SDSC Communications Intern 

Over the years, a combination of overgrazing and intensifying rains has made flooding a critical issue in Kyrgyzstan’s capital city, Bishkek. As a result, University of Arizona researcher Sam Anderson, in collaboration with local partners at Osh State University in Kyrgyzstan, has investigated the link between livestock grazing and its impact on the environment. In his project entitled, “Seasonal Monitoring of Grazing Impacts and Infiltration near Bishkek: A Schema-Compliant Ecological Baseline,” Anderson aims to create an ecological baseline for future research. 

“Building a robust ecological baseline is essential for understanding how seasonal changes in cattle grazing and vegetation cover affect infiltration and for guiding long-term resilience strategies,” Anderson said. “We compared two contrasting watersheds near Bishkek, the overgrazed Alamedin and the relatively ungrazed Ala-Archa, as our primary research sites to gain further clarity on how grazing pressure, soil infiltration and flood risk interact throughout time.” 

To begin quantifying these relationships, the team seasonally measured land characteristics that are typically impacted by grazing – vegetation cover and height, soil compaction, aggregate stability (soil’s resistance to breaking apart), and infiltration rates (how quickly water soaks into the soil) – of land plots in Alamedin and Ala-Archa. These field measurements were then incorporated into the Rangeland Hydrology and Erosion Model (RHEM) to predict the two sites’ runoff and erosion rates. Additionally, they were overlaid with satellite rainfall estimates that supplied the storm inputs for the model. 

Overall, the results demonstrated a strong relationship between vegetation cover and watershed resilience. Areas with greater vegetation cover were more resistant to erosion, reflecting healthier soil structure and higher water-infiltration capacity. Contrastingly, where grazing had reduced vegetation cover and degraded soil, watersheds were more vulnerable to erosion. More specifically, in the overgrazed Alamedin, the data revealed significantly shorter vegetation, greater soil compaction, and higher modeled erosion and runoff rates than in the relatively ungrazed Ala-Archa; In Ala-Archa, the soil remained soft, the vegetation tall and the hydrological conditions (the movement of water within an environment) stable. Furthermore, sites categorized as intact consistently produced the lowest runoff and erosion prediction, while the disturbed sites resulted in the highest values, leaving them vulnerable especially in the face of extreme weather patterns. 

Caption: Study area - Ala-Archa (protected) and Alamedin (grazed)

“Our findings work to participate in the broader conversation of environmental conservation: quantifying the impact of overgrazing on vegetation, soil and hydrology while emphasizing the importance of sustainable grazing management and other environmental regulations,” Anderson said. “Our field data is made intentionally accessible to the public, with systematic tagging, a Jupyter notebook outlining the data collection process and a guideline document, in order to effectively serve as an ecological baseline for future resilient-oriented research.“

Anderson’s research was made possible from funding through EarthCube’s Democratized Cyberinfrastructure for Open Discovery to Enable Research (DeCODER) project, a program dedicated to addressing critical geosciences challenges through data discovery and reuse. His results are now published on Zenodo, a data and software repository for researchers.