A comprehensive flood-vulnerability assessment conducted by the Trichy district administration has revealed alarming data, identifying a significant portion of the district as being in grave danger during heavy rains. The study, which employed advanced Geographic Information System (GIS) tools, has mapped out areas most susceptible to inundation, providing crucial data for disaster preparedness.
Key Findings of the Flood Risk Assessment
The mapping exercise has classified a substantial 373 square kilometres, which accounts for roughly 8% of Trichy district's total area, under the 'very high' flood risk category. Within this vulnerable expanse, authorities have pinpointed 154 specific locations and sorted them into four distinct risk tiers. The assessment indicates that approximately 200,000 residents live within these demarcated high-risk zones, highlighting the scale of potential human impact.
The analysis was carried out with technical support from the PG & Research Department of Geography at Thanthai Periyar Arts and Science College. Experts evaluated five critical parameters to determine flood susceptibility: rainfall patterns, soil type, geomorphology, geology, and land slope. This multi-faceted approach ensures a scientifically robust vulnerability model.
High-Risk Rivers and Urban Pockets
The zones of greatest concern are predominantly located along the banks of the Cauvery and Koraiyar rivers, including several densely populated pockets within Trichy city itself. The report flags heavy rainfall in the Cauvery catchment area and the subsequent water discharge, combined with flows in the Kollidam river, as major threats to the region.
Other specific water bodies also pose localized dangers. Surplus flow in the Ariyaru river, whose catchment extends into parts of neighbouring Dindigul district, can lead to flooding in Vayalur Road, Dheeran Nagar, and Pirattiyur. Similarly, overflow from the Koraiyar river, which drains rainwater from Manapparai, threatens areas like Crawford and Karumandapam.
Among the 154 mapped locations, several city areas have received the dire 'very high' risk ranking. These include Tharanallur Rettaivaikkal, Odathurai, Melachinthamani, and Veeramuthu Nagar. Other notable high-risk zones encompass Srirangam, Uyyakondan Thirumalai, and Manapparai.
Preparedness and Future Action Plans
District disaster management officials have clarified that the primary goal of this mapping is to enhance preparedness, particularly for the northeast monsoon. Over the past decade, drainage congestion and river bank erosion have been identified as key contributors to flooding during this season.
"This mapping is a proactive tool," explained a senior district disaster management official. "It helps us prepare during the northeast monsoon by identifying safe shelters and mobilising support ahead of heavy-rainfall alerts from the India Meteorological Department (IMD). We have been advised to update this list annually to reflect any changes."
To translate this data into actionable safety, authorities plan to organise mock drills. These exercises will focus on areas where the National Disaster Response Force (NDRF) and State Disaster Response Force (SDRF) have previously conducted rescue operations. The aim is to strengthen preparedness among local residents and all stakeholder departments, ensuring a coordinated and efficient response when disaster strikes.
