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Credits & Citation

The algorithm is Matthew Heberger's

The delineation method at the heart of pourpoint, the approach summarized in How it works, is the work of Matthew Heberger (ORCID 0000-0001-9122-0030). He designed the method, validated it against reference watersheds, published it, and released a reference implementation as the open-source, MIT-licensed delineator tool, alongside the point-and-click Global Watersheds web application.

pourpoint is an independent Rust reimplementation of that method. The algorithm design is entirely Heberger's; what pourpoint adds is engineering reach: Heberger's delineator is built specifically around the MERIT-Hydro and MERIT-Basins datasets, while pourpoint runs the same method on normalized HFX inputs. Every raw source fabric requires an adapter compile step. The existence of an adapter does not imply that this project hosts its output; GRIT is the only currently hosted dataset. Because delineator is MIT-licensed, the license permits this reimplementation. This page credits him because correctness and courtesy require it.

A note on lineage

Heberger's own paper is candid about precedent, and so is this page. The idea of combining raster and vector methods for watershed delineation traces back to Djokic and Ye (1999); Heberger's contribution is the modern open-source, free, and global implementation that made the hybrid method fast and widely usable.

The GRIT hydrofabric

pourpoint's canonical hosted example dataset is GRIT (Global River Topology), a global river-network dataset by Wortmann et al. GRIT is a separate work from the delineation algorithm; if you delineate over the GRIT hydrofabric, cite the GRIT vector dataset alongside Heberger's method:

Wortmann, M., et al. (2025). Global River Topology (GRIT) vector datasets. Zenodo. doi:10.5281/zenodo.17435232

Also cite the GRIT paper:

Wortmann, M., et al. (2025). Global River Topology (GRIT). doi:10.1029/2024WR038308

The hosted HFX compilation also includes GRIT's planetary direction and accumulation raster archive. Cite the GRIT raster dataset too:

Wortmann, M., et al. (2025). Global River Topology (GRIT) raster datasets. Zenodo. doi:10.5281/zenodo.15715535

The combined hosted dataset is licensed CC BY-NC 4.0 for NonCommercial use. Installing the MIT-licensed engine does not grant commercial rights to the hosted GRIT data.

Upstream Tech provides only in-kind hosting infrastructure. It is not the project owner, dataset vendor, or commercial partner.

How to cite Heberger's work

If the delineation algorithm matters to your work, please cite Heberger.

The paper:

Heberger, M. (2025). Fast, accurate watershed delineation with a hybrid of raster and vector methods. Manuscript submitted to Environmental Modelling & Software. SSRN preprint: https://doi.org/10.2139/ssrn.5939056 (https://ssrn.com/abstract=5939056). Author copy: preprint PDF.

The Global Watersheds web application:

Heberger, M. Global Watersheds (web application). https://mghydro.com/watersheds

BibTeX for the delineator software:

@software{delineator,
  author    = {Matthew Heberger},
  title     = {delineator: Global Watershed Delineation with Python},
  year      = {2026},
  publisher = {GitHub},
  version   = {2.1},
  url       = {https://github.com/mheberger/delineator}
}

How to cite pourpoint

pourpoint and its Python bindings are MIT-licensed and do not have their own DOI or paper. If you use them in research, cite Heberger's algorithm as above and point to the repository:

pourpoint: watershed delineation from normalized HFX datasets. https://github.com/CooperBigFoot/pourpoint