By Mark Dummett
BBC News, Kaijuri, Bangladesh
The river banks are made of nothing more than clay and sand
The United Nations says it has developed a plan to help the thousands of Bangladeshis who lose their homes every year because of river bank erosion.
Using satellite images, the United Nations Development Programme (UNDP) says it can predict which areas will be destroyed by rivers shifting course, so that the affected people receive assistance.
Every year it is estimated that about 100,000 people are made homeless by the unstoppable force of the country's two largest rivers - the Brahmaputra and the Ganges (which are known in Bangladesh as the Jamuna and the Padma).
Their river banks are made of nothing more than clay and sand, so thousands of hectares of land are washed away each monsoon, when the rivers run fastest.
Usually the rivers' victims receive little help, and many are forced to migrate to the slums of the overcrowded capital, Dhaka
"This is a silent disaster," the UNDP's assistant country director Aminul Islam says.
"Every year thousands of people are losing their lands and they are silently suffering because nobody keeps any records.
"If there were statistics and you put them all together you'd see that this was a much bigger disaster than one single event like a cyclone which draws much more attention and global resources."
The UNDP is currently managing a pilot project in three areas, which are expected to be washed away this year.
It is working with the Dhaka-based Centre for Environmental and Geographic Information Services (CEGIS) to warn people that their homes and fields are in danger.
Ahmad Ali is a victim of river bank erosion
They use red and yellow-coloured flags to indicate risk levels.
They work these out by studying 25 years of satellite images and soil samples.
Their predictions have already proved accurate at Kaijuri, near the city of Sirajganj, north-west of Dhaka.
A 10km stretch of bank there has been destroyed by the Jamuna since the start of the monsoon in June, and 2,000 people have already lost their homes.
"It just happens so quickly," one of the victims, Ahmad Ali said. "There is a splash of water and suddenly the ground you're sitting on disappears."
The head of the local council, Safiuddin Chowdhury, also saw his home crumble into the river, which at this time of year can be 15km wide.
"The only way to explain to people who know nothing about our problem of river bank erosion is this - those who had a very happy and healthy life, with beautiful houses, and fields full of crops and cattle, are now like beggars. They sleep in the markets and in the open," he said.
But the people here are grateful for the warnings they received this year.
"At least this time we were able to save our furniture and possessions," Rahimullah, another victim, said.
"In previous years people just moved when the erosion came up to their doorsteps, when the house was about to collapse into the river."
For the first time, these victims of river bank erosion have been registered, so the hope now is that the government will provide them with support, and help in resettling.
The rivers deposit much of the land they take away further downstream, so if they are lucky, people can still reclaim what they have lost.