Pluvial Flood Hotspots in Zhengzhou: Resident Complaints, Government Replies, and Field Verification

Rapid urbanization and extreme rainfall have increased pluvial flood pressure in dense urban areas, yet many drainage problems emerge at microscale interfaces that conventional flood monitoring does not capture well. Focusing on the built-up area of Zhengzhou, this study uses waterlogging complaints from the People’s Daily Online Leadership Message Board to identify resident-perceived flood hotspots. Government replies, field verification, and built-environment indicators are then combined to examine how these sites are described, assigned, and validated. The complaint records reveal recurrent flood pressure at interface settings, including underground-space entrances, residential-compound–road edges, road depressions, and project boundaries. Field checks confirm that several reported hotspots correspond to visible site conditions. Government replies, however, differ in how clearly they recognize local drainage settings and responsibility boundaries. Persistent mismatches are concentrated at sites shared by multiple actors, and project-edge areas where maintenance and construction responsibilities are difficult to separate. Grid-based diagnosis further shows that planning priority is identified more effectively through the overlap of built-environment exposure, observed site pressure, and governance mismatch than through exposure indicators alone. The study treats complaint–reply exchanges as participatory spatial evidence and proposes a diagnostic procedure linking hotspot interfaces, responsibility boundaries, and field verification for pluvial flood planning.