Assam State Disaster Management Authority (ASDMA) reported that fatalities due to floods and landslides reached 82 with more than 50 lakhs affected this year. This is just the beginning of the season. Even as one wishes that we see no more flood furies, there are already reports of floods and landslides in other parts of the Country.
Why are we seeing floods and landslides year after year? Several factors contribute. First is massive rainfall. Consequently, there are overflowing rivers and collapsed Dams. Inadequate drainage systems and ineffective infrastructure designs add to the misery. Several people contributed disasters like the snowmelt, deforestation, climate change and emission of greenhouse gases compound the tragedy. Consequently, we see water all over, in the homes, in paddy fields, under the bridges, over the bridges, inundating and sometimes washing away everything on the way.
Inadequate capacity within riverbanks to contain high flows, riverbank erosion, silting of riverbeds, landslides leading to obstruction of flow and change in the river course, retardation of flow due to tidal and backwater effects, poor natural drainage in the flood prone area, cyclone and associated heavy rainstorms, cloud bursts, and dam break flows are all reasons. These may look natural to the uninitiated but are all accelerated due to man led development. They bring misery to people destroying infrastructure which is built painstakingly over the years. Certain contributory factors can be mitigated. Others cannot be.
Amongst those that cannot be, is the Moon’s orbit that undergoes a natural alteration, known as ‘wobble’. If this is coupled with rising sea levels, it can lead to dramatic increases in floods. A study by NASA in collaboration with scientists from the University of Hawaii, says this can come true by 2030 and can last for about 10 years thence.
A couple of years ago, the above average monsoon rains resulted in severe flooding in parts of Kerala and Karnataka former being the hardest hit, where at least 350 fatalities were reported and as many as 800,000 people displaced. Will this happen again this year? Is this avoidable? Can the future be secured against such disasters? The solution is simple. Respect mother Nature. It has everything for everyone. It has nothing for our greed. The Assam floods periodically affect at least 10,000 people every year.
Floods are the most recurring of the natural disasters and classified in zones of flooding. Brahmaputra river basin, Ganga River basin, North-West River basin, and Central India and Deccan River basin. Mitigation methodologies vary for each classification. 4,000 billion Cubic Meter is the annual precipitation, in India that includes snowfall. A seasonal rainfall in monsoon is of the order of 3,000 BCM. The Central Water Commission (CWC) under Ministry of Water Resources reports that the annual average area affected by floods is in the excess of 8000 million ha. The National Flood Commission has reported that the total flood prone area of India was more than 40 million ha.
Based on data collected by the Centre on actual areas flooded since 1950, among the top 10 most vulnerable states, Punjab is followed by West Bengal, Bihar, UP, Andhra Pradesh, Haryana, Kerala, Assam, Gujarat and Odisha, in that order.
Apart from primitive embankment management, reluctance of villagers to evacuate even when flood waters cross the danger levels is a serious issue. Aon, a global professional services firm headquartered in London that provides risk, retirement and health consulting, revealed, “Total economic losses in India were estimated to reach as high as Rs 200 billion, and India’s General Insurance Corporation claims possibly reaching up to Rs 20 billion,”.
However, there are benefits of flooding too. For farmers and those in the agricultural sector, it helps in the long run, by providing nutrients to the soil that were lacking. Flood deposits, fine silt or alluvium onto the floodplain that makes the soil more fertile and increases agricultural production.
Each year, around 30 million people are affected by floods. If the prices are adjusted for inflation, the average annual loss because of floods, heavy rains, works out to 15,000 Cr. Apart from these losses at least a thousand lives are lost every year. Floods may be ‘acts of God,’ but flood losses are largely acts of man.
Preventing floods altogether is not feasible. However, Flood mitigation is. It involves management and control of flood water movement. Floodwalls and flood gates can redirect flood waters. Management of people is important through measures such as evacuation. Even dry or wet proofing properties will help. Flood risk maps can be used effectively to proactively evacuate people to higher reaches. Prevention is better than cure. Some more methods such as better flood warning systems, modifying homes and businesses to help withstand floods, constructing buildings above flood levels, tackling climate change, increasing spending on flood defences, protecting wetlands, planting trees strategically, restoring rivers to their natural courses, creating water storage areas, improving soil conditions and creating more flood barriers must all be followed. Risk assessment can play a major role in awareness and insurance in mitigating the financial and other hardships.
A serious question in flood mitigation, is the timing for opening of the flood gates operated by controlling water surface elevation stored. In case of flood bypass systems, floodgates sometimes are used to lower the water levels in a main river or canal channel. Detention basins are also critical. The flow of water must be unhindered and smooth. The timing is extremely important and must be attempted only when the evacuation is complete.
At a time when the Government thrust is on creating smart cities where water supply or the sewage systems are controlled, understanding when water is flowing or if there are leaks, or if a flood is building up is important. Putting a command-and-control system, where the entire water flow situation can be monitored and controlled is the strategy. Can we afford to live through periodic floods that wash away even the basic utilities each year? Our priorities, our respect for nature and mitigation strategies must be equally smart for “God has cared for trees, saved them from drought, disease, avalanches, and a thousand tempests and floods. But he cannot save them from fools” said John Muir, the Scottish-American naturalist, author and environmental philosopher.