Global Monthly Reach-Level Water Surface Slopes from SWOT

This dataset provides global, monthly, reach-level median water surface slope (WSS) derived from the SWOT Level 2 River Single-Pass Vector Product, Version C, aggregated from August 2023 through May 2025. For each reach and month, we compute the median WSS after quality control. We also provide a per-reach annual file that combines the 12 monthly values into an overall median of available months. Companion variables include potential explanatory data from SWORD v16 and GEOGLOWS retrospective daily discharge sampled on the calendar day corresponding to each reach’s monthly median WSS timestamp. The dataset supports the manuscript: Chen, Y., Dhital, S., Cohen, S., Baruah, A., & Devi, D. (2025). Spatial and Temporal Variability in Global River Slopes from the Surface Water and Ocean Topography (SWOT) Satellite (under revision). These data are suitable for hydrologic and hydraulic modeling across spatial scales, particularly studies that consider temporal variability in WSS.