AZ-Hydro — Historical and Projected Arizona Annual Water Use: Software, Input Data, Models, Raster and Well Package Predictions, and Validation at 2 km Resolution (1896–2099)

AZ-Hydro: Historical and Projected Arizona Annual Water Use, 1896–2099

A 2 km-resolution gridded dataset of Arizona groundwater and surface-water withdrawals, irrigation consumptive use, and pumping-induced surface-water capture, spanning 204 years (1896–2099) with quadrature-combined uncertainty bands. Companion data archive for Majumdar et al. (in prep., Nature Scientific Data) and Majumdar et al. (in prep., AGU Earth's Future).

Graphical Abstract: https://github.com/montimaj/az-hydro/blob/main/docs/images/Graphical_Abstract_Fig1.png

What's in this deposit

File

Size

Contents

Audience

az-hydro-headline.7z

~8.8 GB

Focused subset: published per-pixel/per-year predictions (6-band augmented rasters with σ + CV + SNR + 95 % CI), per-well GeoPackage + Parquet, SW capture index, aggregated time series, CAP shortage scenario outputs, validation against USGS/ADWR/Reitz, era-mean and trend spatial figures. Most users want this.

Reviewers, downstream researchers using the published product

az-hydro-data.7z

~80 GB

Full reproducibility archive: all of the above plus raw inputs (GEE tiles, ADWR meter records, well registry, GW basin / AMA-INA / CAP / SRP / streamflow / USBR vectors, statewide WTD), Step 2 cross-validation outputs, intermediate predictor stacks, per-component σ rasters (σ_MACA / σ_Model / σ_Irr / σ_LULC / σ_GW / σ_USBR / σ_CU).

Anyone reproducing the full pipeline from scratch

az-hydro-1.0.0.zip

~55 MB

Source code release (Python pipeline, GEE export scripts, documentation). Same content as the GitHub repository at the tagged release.

Anyone running the pipeline

Inside each .7z, see Data/HEADLINE_README.md (headline archive) or Data/README.md (full archive) for a complete per-directory inventory and external-source citations.

Important: how to unpack the .7z files

The .7z format is not openable by macOS Archive Utility. Use one of:

macOS — Keka or The Unarchiver

Windows — 7-Zip, WinRAR, or Bandizip

Linux — p7zip (e.g. apt install p7zip-full), then 7z x az-hydro-data.7z

LZMA2 + solid-block compression yields ~35 % ratio (74 GB compressed from 209 GB raw; 8.8 GB compressed from ~40 GB raw).

Methods overview

AZ-Hydro is a four-step physics-constrained ML pipeline:

XGBRF prediction of total annual water-use depth per pixel, trained on    per-well ADWR meter records (1984–2024) with 16 predictor bands (climate, ET, Peff, irrigation fraction, well density, canal density, water-rights density, etc.).

Density-ratio partition decomposing the total prediction into Irrigation/Non-Irrigation × GW/SW × CU using era-mapped factors anchored    to USGS Circulars 1950–2015 and ADWR Annual Reports 2016–2024.

Six-component quadrature uncertainty quantification: σ_MACA (5 GCMs) + σ_Model (10 XGBRF seeds, t-corrected) + σ_LULC (4 USGS FORE-SCE    scenarios) + σ_USBR (5 CMIP3 Upper-Colorado streamflow members,  t-corrected) + σ_GW (5 recent ADWR Well Registry snapshots, t-corrected) + σ_CU (analytic propagation through Irrigation Efficiency).

Per-pixel SW Capture Index with σ_GW propagation to quantify pumping-induced streamflow depletion.

Key validations

2016 ADWR Total: model 6.72 MAF vs ADWR ~7.0 MAF (within −0.28 MAF)

2017 ADWR: 6.81 vs 7.0 MAF; GW share 44.9 % vs 41 % (within 4 pp)

2015 USGS GW pumping: 2.96 vs USGS 3.09 MAF (within −0.13 MAF)

2019–2020 ADWR irrigation share: 73.8 % vs 74 % (essentially exact)

WestWater (2026) CAP shortage scenarios: AZ-Hydro Basic Coordination cumulative ΔGW = 7.24 MAF vs WestWater Fig 4 anchor 8.0 MAF (within   −9 %); Extreme Shortage = 13.08 MAF vs Fig 4 anchor 8.7 MAF (gap reflects AZ-Hydro's no-regulatory-ceiling framing).

CAP delivery shortage scenario sweep

Eight scenarios (Baseline_900kAF, DCP Tier 0/1/2a/2b/3, WestWater Basic Coordination, Extreme Shortage) re-partitioned 2026–2099. Cumulative additional GW pumping over 2027–2060: DCP Tier 3 = 10.7 MAF, Basic Coordination = 7.24 MAF, Extreme Shortage = 13.08 MAF. Spatial maps (basin choropleth, per-pixel cumulative ΔGW, σ_cum context, basin/pixel signal-to-noise) included for both 2027–2060 (WestWater anchor) and 2027–2099 windows.

External datasets required to reproduce the pipeline (not redistributed here)

The pipeline reads four USGS ScienceBase data products that you must download separately:

USGS NHM withdrawals (Haynes et al. 2023)   — irrigation withdrawals + efficiency by HUC12, 2000–2020

USGS NHM CU / IE reanalysis (Martin et al. 2023;   Martin et al. 2025) — irrigation consumptive use + Peff by HUC12

USGS public-supply reanalysis (Luukkonen et al. 2023;   Alzraiee et al. 2024) — public-supply withdrawals by HUC12

USGS Reitz historical ET / Peff (Reitz et al. 2023;   Reitz, Sanford & Saxe 2023) — 800 m gridded irrigation ET, 1980–2018

Bundled here directly: ADWR Well Registry, ADWR Meter Data, GW basin / AMA-INA / CAP / SRP / streamflow / USBR vectors, HarDWR water-rights shapefile (Lisk et al. 2024), GRAIN canal network (Suresh et al. 2026), and the Ma et al. 2026 statewide WTD TIFs.

See Data/README.md inside each .7z for exact filename / sub-directory naming required.

Citation

Data archive (this deposit):

Majumdar, S., Smith, R.G., ReVelle, P., Hasan, M.F., & Wogenstahl, C. (2026). AZ-Hydro — Historical and Projected Arizona Annual Water Use: Software, Input Data, Models, Raster and Well GeoPackage Predictions, and Validation at 2 km Resolution (1896–2099). Zenodo. https://doi.org/10.5281/zenodo.19057936

Companion papers:

Majumdar, S., Smith, R.G., ReVelle, P., Hasan, M.F., & Wogenstahl, C.  (2026). Historical and projected groundwater/surface-water withdrawals, irrigation consumptive use, and pumping-induced surface water capture for Arizona, 1896–2099. In prep. for Nature Scientific Data.

Majumdar, S., Smith, R.G., ReVelle, P., Hasan, M.F., & Wogenstahl, C. (2026). Where Arizona's Water Goes: Declining Agricultural Dominance and Rising Urban Demand Drive a Two-Century Shift in Withdrawal Patterns (1896–2099). In prep. for AGU Earth's Future.

License

Data archives (az-hydro-data.7z, az-hydro-headline.7z): CC-BY-4.0

Source code (az-hydro-1.0.0.zip): BSD 3-Clause "Revised" (see   LICENSE inside the zip)

External datasets bundled here (HarDWR, GRAIN, WTD, ADWR products)   retain their original upstream licenses

Acknowledgments

This work was supported by NASA (Grant numbers 80NSSC21K0979 and 80NSSC23K1453) and U.S. Army Corps of Engineers (Grant number W912HZ25C0016). We thank the open-source software and data communities, the OpenET consortium, and the Arizona Department of Water Resources for making their resources and datasets publicly available, and Google Earth Engine for compute and storage support. S.M. and P.R. acknowledge Dr. Justin L. Huntington, Christopher Pearson, Charles G. Morton, Blake A. Minor, Dr. Samapriya Roy at the Desert Research Institute, and Dr. David Ketchum at the University of Montana for their contributions to related projects that informed this work. We also thank Rahel Pommerenke at Colorado State University for presenting preliminary results from this work at the 2025 ESA Living Planet Symposium. The views expressed herein are those of the authors and do not necessarily reflect those of the funding agencies.

Related links

Live web app — AZ-Hydro Explorer: https://azhydro.projects.earthengine.app/view/azhydro-explorer (interactive GEE App: year slider 1896–2099, side-by-side category compare, click-driven pixel/basin/sub-basin/well time series with 95 % CI, CAP scenario × window dropdowns)

GitHub repository: https://github.com/montimaj/az-hydro

Issue tracker / bug reports: https://github.com/montimaj/az-hydro/issues

Nature Scientific Data preprint (when available): (link)

AGU Earth's Future preprint (when available): (link)