Real-time rainfall monitoring and flood inundation forecasting for the city of Kolkata

Abstract

Kolkata, the capital city of the Indian state of West Bengal, is prone to occasional flooding at times of moderate to heavy rainfall owing to relatively flat terrain and tide-dominated drainage outfalls. This article describes an instrumentation network that attempts to capture the distributed rainfall information in real time over the city with the help of an array of automatic rain gauges. Digital water level sensors, which monitor the elevations of the drainage channels, provide information about the water level in real time. Both rainfall and water level data, transmitted through GSM technology as SMS to a server at the Indian Institute of Technology (IIT) Kharagpur, get uploaded to a website continuously. Future plans include linking the rainfall and channel water level data with an overland flow and inundation numerical simulation model for predicting possible inundation scenarios in the city. Plans also propose to utilise the real-time data of the Kolkata Doppler Weather Radar for supplementing the ground rainfall data for producing longer lead-time forecasts.