Smart Flood Detection and Impact Mapping System: An IoT-Driven Framework for Real-Time Early Warning and Spatial Risk Visualisation

Abstract: Year after year, floods establish themselves as one of nature’s most relentless and costly hazards — stripping communities of lives, agricultural stability, and infrastructure built over generations. Much of this destruction is not unavoidable; a substantial share of it can be traced directly to the failure of existing warning systems to reach at- risk populations quickly enough, and reliably enough, when conditions deteriorate. This paper presents the Smart Flood Detection and Impact Mapping System, a hardware-first, internet-independent platform that integrates IoT environmental sensing, embedded microcontroller processing, and GSM cellular communication to deliver autonomous real-time flood alerts without relying on cloud infrastructure. The system continuously measures water level, rainfall intensity, temperature, and humidity through field-deployed sensor arrays; evaluates incoming readings against pre- calibrated safety thresholds; and immediately dispatches SMS warnings to residents, farmers, local authorities, and emergency management teams the moment dangerous conditions are detected. Because alert delivery travels through the GSM cellular network rather than the internet, the system remains fully operational during the network outages that characteristically accompany severe weather events. A complementary Python-based visualisation pipeline converts accumulated sensor telemetry into colour-indexed spatial heat maps, providing disaster coordinators with a structured, geographically explicit picture of inundation severity that supports evidence-based evacuation planning and rescue resource allocation. The resulting system is low-cost, energy-efficient, portable, and suited for deployment across both urban centres and the remote rural communities where the gap between flood risk and monitoring capability is widest.

Keywords: Flood Monitoring, IoT, GSM Module, Early Warning System, Heat Mapping, Disaster Management, Real-Time Monitoring, Embedded Systems, Arduino, Edge Computing, Environmental Sensing, SMS Alert, SIM800L.