UAV-Derived Volumetric Monitoring of Artificial Ice Reservoirs for Climate Adaptation in Ladakh, India

Climate change is exacerbating spring water scarcity in the trans-Himalayan region of Ladakh, India, owing to increased uncertainty in winter snowfall. Amidst this growing concern, artificial ice reservoirs emerged as a climate adaptation technique and have gone through several engineering iterations since the late 1980s. These gravity-based systems capture winter streamflow in the form of ice and release meltwater during the crucial spring agricultural season. Despite their rapid implementation across the region, data integration into their construction process and quantitative monitoring of their water systems and volumetrics remain limited.

This study demonstrates the application of a lightweight, consumer-grade unmanned aerial vehicle (UAV) for photogrammetry-based volumetric analysis of ice reservoirs. A DJI Mini 3 was used to conduct 20 repeat surveys during the winter–spring 2024–2025 season on ice reservoirs constructed by a Ladakh-based startup, Acres of Ice, in two villages: Igoo and Sakti. Oblique imagery was captured at a 65° camera angle with 80% overlap to constrain ice reservoir geometries. Photogrammetric data processing was used to generate high-resolution digital elevation models (DEMs), which were coregistered using ground control points surveyed in situ with a Trimble RS2 GNSS with real-time kinematics (RTK). Finally, on-site weather station and pipeline-based sensor inputs provided water and air temperatures, as well as discharge data, to further contextualise the construction process.

Preliminary results reveal a maximum ice volume of approximately 4,116 m³ at the Igoo site, with mean discharge rates of ~3.5 L s⁻¹ and a low water-to-ice efficiency of 13% between November and April. During this period, water temperature averaged 4 °C and mean air temperatures averaged −8 °C. At the Sakti site, ice volumes reached ~1,814 m³, with average discharge rates of ~5 L s⁻¹, indicating a lower water-to-ice efficiency of 6% between December and April. During this period, water temperatures averaged ~2 °C, while air temperatures averaged −10 °C. These results indicate a need to optimise design parameters for water management and better integrate microclimate data into ice reservoir construction.

This research offers the first comprehensive, data-driven approach to volumetric measurements of ice reservoirs, laying the groundwork for future studies on groundwater hydrology, watershed management, and socio-ecological impacts, and contributing to a holistic, scalable approach to adaptive climate strategies in high-altitude villages in Ladakh.