Land surface hydrology is characterized at selected sites (area extent up to 400 km²) in arctic and sub-arctic environments by (1) open water classification at a range of spatial resolutions (nominal 3 m from ALOS PRISM, 10 m from ALOS AVNIR, ~7/16m from ALOS PALSAR fine beam), (2) the topographic wetness index (based on 10 m DEMs from ALOS PRISM where available, or the 90 m ESA DUE Permafrost dataset) and (3) seasonal inundation dynamics (75 m from ENVISAT ASAR Wide swath).The datasets are available as GeoTIFFs grouped by site and include documentation (pdf), validation results and an overview map as png at selected sites. The dataset has been compiled as part of the PAGE21 WP5 'Multi-scale integration and remote sensing'.ALOS datasets have been available through JAXA PI agreements #80, and #1200 by Vienna University of Technology.