Between 2001 and 2018, Odisha witnessed repeated floods and cyclone-induced inundations that devastated villages, damaged infrastructure, destroyed crops and displaced millions of people. From the overflowing Mahanadi and Brahmani rivers in coastal districts to flash floods in the hilly southern regions, the disasters revealed how vulnerable large parts of the state remain to extreme rainfall and cyclonic systems. These recurring events also highlighted the urgent need for scientific flood mapping and long-term planning based on actual flood experiences across Odisha.
The repeated floods during this period affected extensive areas in districts such as Kendrapara, Jagatsinghpur, Bhadrak, Balasore, Jajpur, Cuttack, Ganjam and Gajapati. Agricultural lands remained submerged for days, roads and embankments were breached and communication systems collapsed in many places. Lakhs of people were displaced repeatedly, often taking shelter in schools, cyclone shelters and elevated embankments. Floodwaters destroyed standing crops, contaminated drinking water sources and severely disrupted livelihoods dependent on agriculture and fisheries.
The floods of 2006, 2007, 2008 and 2009 demonstrated the recurring nature of monsoon flooding in Odisha’s river basins. Rivers overflowing simultaneously due to heavy rainfall across catchment areas inundated low-lying settlements and deltaic plains. The repeated flooding of agricultural lands caused severe economic distress among farming communities. Damage to roads, bridges, irrigation channels and power supply systems further intensified the crisis.
Cyclone-induced floods added another layer of vulnerability. Cyclone Phailin in 2013 caused widespread destruction across coastal Odisha. Heavy rainfall and rising river levels submerged large tracts of farmland and damaged houses and infrastructure in several districts. Although improved evacuation measures helped reduce casualties, the economic damage remained enormous.
Similarly, Cyclone Titli in 2018 caused severe flooding and landslides in southern Odisha districts such as Gajapati, Ganjam and Rayagada. The disaster highlighted that Odisha’s flood risks are not limited to coastal plains alone. Hilly districts also face serious threats from intense rainfall, flash floods and slope failures.
These repeated disasters made it increasingly clear that Odisha required a scientific understanding of flood-prone areas based not on assumptions, but on actual flood inundation patterns observed over many years. This is where satellite-based flood hazard mapping became extremely important.
Using satellite remote sensing technology, scientists analysed flood inundation across Odisha over an 18-year period from 2001 to 2018. Nearly 100 satellite datasets from Indian and international satellites were used to identify areas repeatedly submerged during floods and cyclones. By overlaying flood inundation maps from multiple years, it became possible to classify areas according to the frequency and extent of flooding.
The flood hazard mapping exercise categorised flood-prone regions into five classes i.e., very high, high, moderate, low and very low hazard zones. Areas repeatedly inundated during floods were identified as high-risk zones. District administrations also carried out field verification of the mapped flood-prone areas to ensure accuracy.
The importance of such flood hazard mapping lies in its practical applications. The mapping helps identify which villages, agricultural lands and infrastructure corridors are repeatedly affected by floods. This information enables authorities to prioritize flood preparedness, strengthen embankments, improve drainage systems and plan evacuation routes more effectively.
The hazard mapping also supports long-term land-use planning. Floodplains that face repeated inundation can be regulated more carefully to avoid unsafe settlement expansion and infrastructure development. Public infrastructure such as roads, bridges, schools and hospitals can be planned with flood resilience in mind. The maps also help in crop planning, watershed management and climate adaptation strategies.
One of the most significant aspects of the mapping effort was the use of satellite remote sensing technology. Optical and microwave satellite sensors enabled scientists to observe floodwaters over large areas, even during cloudy monsoon conditions. Synthetic Aperture Radar (SAR) sensors from satellites such as RISAT and Sentinel proved especially useful because they could monitor inundation through cloud cover during storms and heavy rainfall.
The flood experiences between 2001 and 2018 also demonstrated that flood management cannot rely only on structural measures such as dams and embankments. Odisha already has extensive flood control systems, including embankments, drainage channels and reservoirs such as Hirakud and Rengali. However, repeated inundation showed that non-structural approaches like hazard zonation, floodplain regulation and scientific planning are equally critical.
The flood hazard mapping initiative therefore emerged as an important tool for disaster risk reduction. It transformed years of flood experiences into actionable scientific information. Instead of responding to floods only after disasters occur, authorities can now use historical inundation patterns to anticipate risk, strengthen preparedness and reduce future losses.
The repeated floods during this period also highlighted broader environmental concerns. River siltation, shrinking wetlands, poor drainage and encroachment into floodplains have increased vulnerability in many regions. Climate change is expected to intensify extreme rainfall and cyclonic activity over the Bay of Bengal, making scientific flood risk assessment even more important in the future.
Odisha’s experience between 2001 and 2018 demonstrates that floods are not isolated natural events but recurring developmental challenges affecting agriculture, infrastructure, livelihoods and public health. By scientifically documenting flood-prone areas through satellite-based analysis, Odisha has taken a significant step toward more informed disaster preparedness, sustainable planning and climate resilience.
Dr. Bishnupada Sethi
The author is the Chairman of OFDC and Chief Administrator of KBK districts of Odisha.
