Study sites

Seven real river reaches, each anchored to a real, already-public town or village named in the source reporting itself — not a precise mine coordinate. See each source before drawing any conclusion about the reach.

Yamuna — Kairana, India

Case study — reported extraction

Reporting period: 2019-2024 · Label tier: C · 146 usable sample points

https://sandrp.in/2024/08/24/uttar-pradesh-yamuna-aug-2024-ngt-com-finds-sand-mining-rules-violated/

Krishna — Vijayawada, India

Case study — reported extraction

Reporting period: 2016-2024 · Label tier: C · 146 usable sample points

https://sandrp.in/2020/06/19/andhra-pradesh-riverbed-mining-2020-quicksand-of-mismanagement/

Dudhganga — Badgam, India

Case study — reported extraction

Reporting period: 2021-2025 · Label tier: C · 150 usable sample points

https://kashmirobserver.net/2025/10/23/who-is-plundering-doodh-ganga-again/

Mekong (Hậu/Bassac branch) — Châu Đốc, Vietnam

Case study — reported extraction

Reporting period: 2018-2020 · Label tier: C · 44 usable sample points

https://www.nature.com/articles/s43247-023-01161-1

Benue — Makurdi, Nigeria

Case study — reported extraction

Reporting period: unknown (see data_provenance.md open question 5) · Label tier: C · 150 usable sample points

https://rsisinternational.org/journals/ijrias/articles/socio-economic-and-environmental-impact-of-sand-mining-on-the-floodplains-of-river-benue-makurdi-town-benue-state-nigeria/

Kallada — Kollam, India

Comparison — no report found

Reporting period: ban since 2015, enforcement disputed · Label tier: C · 103 usable sample points

https://www.thequint.com/news/india/in-news-sand-mining-banned-in-6-rivers-by-kerala-state-government

Saint Croix River — Grantsburg, USA

Comparison — no report found

Reporting period: undated (adjacent frac-sand operation, not in-channel) · Label tier: C · 70 usable sample points

https://www.nps.gov/sacn/blogs/whats-the-matter-with-the-sand.htm

Reach AOIs are built from live OpenStreetMap river geometry clipped to a ~13-27km window around the anchor town, buffered 600m — reach-scale, not point-precise. See Methods for the full construction process and its limitations (fixed buffer width, crowd-sourced geometry).