By K Rajan in New Delhi
Surrounded by three seas — Arabian Sea, Indian Ocean and Bay of Bengal– India presents a strange paradox – of coexistence of abundance and scarcity at the same time. Almost 40 million hectares or 12.5% area covering 10 states – West Bengal, Orissa, Andhra Pradesh, Kerala, Assam, Bihar, Gujarat, Uttar Pradesh, Haryana and Punjab is ravaged by reoccurring floods while about 50 million peopleinhabiting 68% arable land of the country in seven states Rajasthan, Gujarat, Maharashtra, Uttar Pradesh, Madhya Pradesh, Orissa and Andhra Pradesh go place to place looking for water with parched throats, dry fields and cattle dying on account of extreme drought. The real tragedy is that some 108.11 million hectares out of a total 329 Million hectares land area is drought prone.
Three of the main rivers Brahmaputra, Ganga and Yamuna swell up due to southwest monsoon rains causing flood in the adjacent areas. The entire central India suffers the fury of the torrential rains and flash floods. The other flood prone areas are on the banks and deltas of Ravi, Yamuna-Sahibi, Gandak, Sutlej, Ganga, Ghaggar, Kosi, Teesta, Brahmaputra, Mahanadi, Mahananda, Damodar, Godavari, Mayurakshi, Sabarmati and their tributaries.
The flood prone areas on the north-Indian plains can be broadly categorized into:
- Ganga Basin: Areas in West Bengal, Bihar and Uttar Pradesh which get flooded by the Ganga, Sarada, Rapti, Gandak and Ghagra. The Yamuna mostly floods Haryana and Delhi. Kosi, Burhi, Bagmati, Gandak, Kamla and many small rivers inundate Bihar every year while Mahananda, Bhagirathi, Damodar and Ajay causes floods in West Bengal.
- Brahmaputra and Barak Basins: Brahmaputra and Barak rivers along with their tributaries flood the northeastern states like West Bengal, Assam and Sikkim. Jaldakha, Teesta and Torsa overflow their banks in northern West Bengal and Manipur.
- Central India and Deccan Rivers Basin: Mahanadi, Baitarni and Brahmani cause havoc In Orissa. Heavy rainfall causes Narmada, Godavari, Tapi, Krishna and Mahanadi to flood Southern and central India. Cyclonic storms in Godavari, Mahanadi and Krishna lead to deluge in Coastal Andhra, Orissa and Tamil Nadu.
Bihar is the most flood-prone State- 76 % population in the north Bihar and 73% i.e. 68800 sq Km geographical area is flood affected. It has not only seen the highest number of floods in the last 30 years – in 1978, 1987, 1998, 2004 and 2007 but each successive flood widened the area it could flood in future as well. A number of Himalaya rivers originating in Nepal – Kosi, Gandak, Burhi Gandak, Bagmati, Kamla Balan, Mahananda and Adhwara deposit high discharge and sediments in the plains of Bihar. Only 35% of catchments area of these rivers falls in Bihar and the rest is in Nepal/Tibet. In 2004 even though Ganga was not in spate, the so called secondary river Bagmati, Kamla and Adhwara claimed 800 human lives and damaged a 23490 Sq Km area.
A flood is caused when water overflows the banks of a river due to cracks or damage to its banks or dikes, or heavy accumulation of rain water and submerges land on its sides. Floods happen when the soil and vegetation cannot absorb the falling rain or when water runs off the land in such quantities that it cannot be carried in normal stream channels or retained in natural ponds and human-made reservoirs. Flash floods are the result of too much rain falling in too small an area, in too short a time. On the contrary flash floods are caused by rapid flooding of low lying areas, washes, dry lakes and basins due to heavy rain caused by severe thunderstorm, hurricane, tropical storm or water from rapidly melting snowfields. Flash floods have a short time fuse — that is they can flood an area in less than six hours. While floods occur over hours and days Flash floods frequently occur in seconds and minutes.
Typically, flash floods occur at night and when there is an abundance of atmospheric moisture. Flash-flood waves, moving at incredible speeds, can roll boulders, tear out trees, destroy buildings and bridges, and scour out new channels. Killing walls of water can reach 10–20 ft and lead to quick rise in water levels of small streams. Flash floods can begin before the rain stops falling. There is little time between detection and flood crest. Swift action is essential for the protection of life and property.
A cloudburst is sudden, abrupt, heavy or rapid unforecasted rainfall, hail or thunderstorm, usually no longer than a few minutes but capable of causing massive flashflood. In the Indian subcontinent, cloudburst usually occurs when a monsoon cloud drifts from the Arabian Sea or the Bengal Bay bursts, bringing moderate to heavy rainfall as high as 75 millimeters per hour. Cloudburst’s can be disastrous and often lead to flashfloods.
According to the Tenth Five Year Plan, natural disasters have affected 6% of the Indian population and 24% of deaths in Asia were caused by disasters in India. Almost 2% of national GDP was lost due to natural disasters, and nearly 12% of Government revenue was spent on relief, rehabilitation and reconstruction between 1996 and 2001. A World Bank study equates natural disasters as the greatest impediment to India’s economic development.
Destructive floods occur hundreds of times each year in every part of United States. Floods are the reason why some 75,000 Americans are forced to vacate their homes, nearly 127 deaths and an estimated $2 billion worth of property damage every year. Between1985–2001, the number of floods or flash floods registered a jump from 361 (1988) to 3,376 in 1998. A total of 32,047 flash flood/floods were recorded in 1985–2001.
Approximately 30 million people living in the Indo–Gangetic–Brahmaputra plains are exposed to the flood hazard almost without fail every year. A few hundred lives are lost, millions are rendered homeless and several hectares of crops are damaged every year. Almost 75% of the total rainfall occurs over a short monsoon season (June – September). Floods are a perennial phenomenon in at least 5 states – Assam, Bihar, Orissa, Uttar Pradesh and West Bengal but lately floods have also occurred in areas that are normally not flood prone. For instance even drought prone parts of Rajasthan experienced floods in 2006. All this is the impact of climate change.
About 50 million people are affected annually by drought in about 40 million hectares of rain-fed areas prone to scanty or no rain. Nineout of 36 meteorological subdivisions have poor rainfall. Some 33% areas receive less than 750 mm rainfall (low) and 35 % area receive between 750 to 1125 mm rainfall (Medium rainfall) and only 32 % area has high rainfall (>1126 mm).
Recurrent drought is the cause of extreme poverty, unemployment and malnutrition in arid Rajasthan and Gujarat as well as parts of Uttar Pradesh, Madhya Pradesh, Orissa and Andhra.
Almost 75% of the annual rainfall of 400 million hectare meters is received during four months of monsoon (June- September) as a result almost all the rivers are saturated during this period. The sediment deposition, drainage congestion and sea tides in the coastal plains leads to floods affecting some 30 million people every yearin the Indo–Gangetic–Brahmaputra plains
The main cause of all this is that while the demand for water has risen by over 800 BCM, the supply has stagnated at 1,123 billion cubic metres (BCM). A NASA study groundwater predicted faster depletion of groundwater than its replenishment in Punjab, Haryana, Delhi and parts of Uttar Pradesh and Bihar. According to a study by the Forum for Policy Dialogue on Water Conflict in India, parts of Rajasthan, Vidharba, Bundelkhand and Uttar Pradesh have become water-deficient.
As a result some 17,500 farmers committed suicide in the water-deficient areas and the in the near future water riots are likely to aggravate in cities like Delhi where 30% of the population gets less than 30 litre per person per day while 5% get about 200 litres. In Mumbai, 34% of the population gets less than 75 litre, while 8% get more than 175 litres. The situation is unlikely to improve with demand set to outpace supply in the next decade. By 2020, India’s water demand is expected to be around 1,000 BCM against the supply of only 700 BCM.
This has serious implications in India where in spite of spending close to Rs 1,20,000 crore only only 30% of cropped land has been irrigated as compared to the global average of 60%.
As a result farmers in different parts of India have to depend on bore wells – which are depleting the water table even faster. All this is a vicious circle.