QGIS
The free, open-source GIS that has become the default spatial platform for water engineers worldwide.
Global 10m land cover from Sentinel-1/2 — the highest-resolution free global land cover map available.
by European Space Agency
ESA WorldCover classifies the entire global land surface at 10m resolution into 11 land cover classes, derived from Sentinel-1 radar and Sentinel-2 optical composites for 2020 and 2021, validated with a dedicated field campaign. At 10m it resolves individual fields and urban blocks that 300m-1km legacy land cover products (like ESA CCI Land Cover) blur together.
For runoff-coefficient and curve-number derivation, impervious-surface estimation and any study where land-cover resolution matters as much as its classification accuracy, WorldCover is the current global standard.
Other geospatial & hydro-gis tools covering similar workflow stages.
The free, open-source GIS that has become the default spatial platform for water engineers worldwide.

500+ fast geospatial analysis tools with the best DEM hydrology toolkit in open source.
JAXA's 30m global DSM from PRISM stereo imagery — a strong third opinion alongside SRTM and Copernicus DEM.
A 30m global DEM reaching to 83° latitude — the go-to where SRTM/NASADEM have no coverage at all.
Esri's free hydrology framework for ArcGIS Pro — terrain preprocessing and the data model behind many agency workflows.
ESA's TanDEM-X-derived global DEM — the most accurate free global surface model available today.