Erdőfigyelő: linking citizen reports and satellite alerts for forest and water monitoring in Hungary

Erdőfigyelő (Hungarian for “forest watcher”; forest.equora.institute) is a public web system that links citizen reports on forests and water, open satellite change alerts, and forest-compartment records from the Hungarian National Forest Stand Database (NÉBIH) on a single map. This white paper describes the architecture, the data sources and the processing methods — a forest mask, cell-based patch delineation, the per-patch daily alerted area, pixel-level intersection with Natura 2000 sites and a single-date 2021 tree-cover flag from ESA WorldCover — as well as report moderation and privacy-by-design measures. First results as of 30 September 2026: between 1 January and 21 September 2026, 3,734 DIST-ALERT patches of at least 3 ha were recorded within the forest mask (total patch area 30,994.5 ha). Of the tree cover loss in Hungary between 2001 and 2017 (approx. 182 kha), 81.7% falls on cells classified as tree cover in ESA WorldCover 2021. In the Börzsöny sample area, 87.4% of the 582.8 ha alerted in the third quarter of 2026 lies within Natura 2000 sites. Pixel-level intermediate results are published, so that the area figures can be recomputed independently. The paper documents the limitations, the corrections made after two rounds of independent expert review, and a research agenda led by a pre-specified, stratified national validation (Olofsson et al. 2014; Stehman 2014). Files: English version (erdofigyelo-white-paper-v1.0-en.pdf) and Hungarian version (erdofigyelo-white-paper-v1.0-hu.pdf).Open data (CC BY 4.0): forest.equora.institute/nyilt-adat Magyar összefoglaló. Az Erdőfigyelő nyilvános webes rendszer, amely egy térképen kapcsolja össze a lakossági erdő- és vízügyi bejelentéseket, a nyilvános műholdas változásjelzéseket és a NÉBIH erdőrészlet-adatait. A dokumentum a rendszer felépítését, módszertanát, első eredményeit, korlátait és kutatási tervét írja le; a magyar változat a második fájl.