A global instantaneous reservoir water level product from ICESat-2 (2018-2025)

This dataset provides the Global, Instantaneous Reservoir Water Level Product from ICESat-2 (2018-2025), as described in the GIScience & Remote Sensing manuscript. This product addresses critical gaps in current hydrological monitoring by leveraging the unique capabilities of NASA's ICESat-2 photon-counting lidar. Its novelty is twofold: 1) It provides enhanced spatial coverage, effectively monitoring reservoirs in complex topographies (e.g., narrow river valleys) and smaller surface areas often missed by traditional radar altimetry. 2) It delivers "instantaneous" retrievals for each satellite overpass, rather than aggregated monthly or annual means. This is crucial for capturing event-scale hydrological dynamics (such as flood peaks and rapid drawdowns) that are masked by temporally averaged data. The product was rigorously validated against in-situ measurements from 46 globally distributed reservoirs, demonstrating exceptionally high accuracy (Pearson’s r = 0.995, RMSE = 1.05 m, bias = –0.18 m). The dataset is provided in CSV / shapefile format and includes unique reservoir identifiers, acquisition timestamps, latitude, longitude, and instantaneous water levels (meters, referenced to WGS84).