By Simon Denyer

NEW DELHI, Aug 8 (Reuters) - Climate change might get some blame for South Asia's catastrophic floods, but government ineptitude has dramatically magnified the misery facing tens of millions of people in India, aid groups and experts say.

Global warming is likely to cause even heavier monsoons with more devastating storms in the region, and India needs to wake up fast to the risks.

"You can blame it on climate change or you can blame it on other factors, but the frequency and misery due to flooding is increasing with each passing year," said P.V. Unnikrishnan, ActionAid India's emergencies adviser.

"But what we are seeing is more of a knee-jerk, reactionary response that lacks both sensitivity and vision," he added. "The government is not going the extra mile to reach out to the poor."

At least 490 people have been killed and 50 million affected by the floods hitting northern India, Bangladesh and Nepal in the past three weeks.

More than 100,000 people are still marooned -- many perched on rooftops -- in eastern India's Bihar, a state that is a byword for poverty at the best of times. Anger is rising at what is seen as the lackadaisical response of the state government.

Four air force helicopters were pressed into action in Bihar this week, not nearly enough to bring food and drinking water to all the victims, U.N. officials say.

To add insult to injury, officials have been accused of stealing or hoarding food, while a 17-year-old boy was killed when police opened fire on an angry crowd.

The United Nations says state governments, especially in Bihar, simply do not have the capacity to deal with a crisis of almost unprecedented proportions. The governments themselves admit to being overwhelmed and say they are doing their best.

But a lack of planning for the vagaries of the annual monsoon seems to have left parts of India cruelly exposed.

"How do we stop a disaster becoming a crisis? That is exactly when disaster preparedness comes in," Unnikrishnan said.

"If we make an investment of one pound in disaster prevention and reduction, that has 100 times more effect than after disaster strikes."

WHEN THE LEVEE BREAKS

Measures like building shelters on higher ground, raising borewells to prevent drinking water becoming contaminated and developing early warning systems can all help. Officials need to be trained and systems put in place to deliver food and water.

"The measures are there, it's only a question of the government being conscious, worried and serious about it," said Aditi Kapoor of Oxfam. "The response would still be needed, but at least peoples' lives would be saved."

India has set up community early warning systems on its east coast after frequent devastating cyclones and the 2004 tsunami.

Low-lying Bangladesh is also better prepared these days for storms and floods, with warning systems and provision for evacuation, shelter, food distribution and healthcare.

Two-thirds of the country is submerged and 164 people died in flooding this year, but the annual tolls have fallen since the 1998 floods killed more than 3,500.

But in northern India, many experts say, state governments have taken completely the wrong approach.

Embankments built along many rivers have simply made matters worse, causing catastrophic flooding when they break and preventing water draining away again -- just as the levee breaks did when Hurricane Katrina struck New Orleans in 2005.

Siltation has reduced the effective height of many embankments, which have also been poorly maintained.

Himanshu Thakkar of the South Asia Network on Dams, Rivers and People has logged nearly 100 reports of embankments being breached in Bihar and Uttar Pradesh this year.

"Embankment floods are sudden, have greater destructive power, often bring a huge quantity of sand and remain for longer periods than would have been the case without the embankments."

CLIMATE CHANGE

Nevertheless, this year has been exceptional. Many Biharis had never seen as much rain in their lifetimes, around 900 mm, close to a year's quota in just two weeks of incessant deluge.

At the Indian Meteorological Department (IMD), officials are unwilling to blame global warming for any individual weather pattern, and say that the average annual rainfall across India does not appear to have changed much.

What has changed -- and risen significantly -- is the number of "extreme rainfall events", says the IMD's M. Rajeevan.

UNICEF's India health chief Marzio Babille says what many now believe -- climate change has led to a dramatic increase in the scale and frequency of natural disasters, and demands a completely new response.

"What emerges from my experience in Bihar is that the scale of the inundation is so vast, even communities that are used to coping with floods were completely overwhelmed," he said.

"We cannot continue to respond to these kinds of challenges with the same pace or technology we did 10 years ago."

AlertNet news is provided by