A Decade of PhotoMappers: A Longitudinal Study of Crowdsourced Disaster Photos Geolocalization with Vision-Language Models and Geospatial Reasoning
This study analyzes a ten-year dataset from the PhotoMappers crowdsourced disaster-mapping initiative and tests GeoAI models on cross-view image geolocalization and geographic reasoning. Fusing volunteered geographic information, street-view imagery, and remote sensing imagery via Sinkhorn re-ranking achieved a top-1 retrieval recall rate of 40.90%, with yearly performance fluctuating between 25.00% and 65.07%. Evaluation across 30 geographic indicators showed that the Qwen3.6-27B vision-language model achieved 67% agreement with human geographic reasoning, outperforming InternVL3-8B at 51%, though both models struggled to interpret fine-grained, localized place cues.
Why it matters — Automated GeoAI models can scale up the retrieval of candidate locations for disaster imagery, but human interpretation remains essential for verifying ambiguous, context-dependent local features.