By M Ilyas Khan
BBC News, Keti Bandar, southern Pakistan
Keti Bandar was once a thriving river port in the Indus river delta region in southern Pakistan, with impressive public buildings, a customs office and warehouses for exports.
Today, it can barely stay above water.
Sea waves lash against its protective embankments on three sides, leaving only a thin, 2km long isthmus by way of a land bridge to the mainland.
And the water levels keep rising.
Two years ago, the high tide barely came up to the ruins of a rice mill located just outside the town. Now that has been completely submerged.
"The tide will ebb, but it will come back with greater force. Two more years, and the whole town will be under water," said Bachal Khanejo, a local boatman.
While there is still time to save Keti, the town of Kharo Chhan, about 20 minutes drive east, has reached the point of no return.
"In 1946, it was a part of the mainland," says Abdullah Murgher, a local farmer. It is now an island, about 30 minutes' boat ride from the shore.
The signs of a prosperous past are still visible, such as the crumbling pillars of a vast villa that belonged to a Hindu village head.
But all that remains on the island today are a few hundred fishermen's huts, made of straw-mat walls and thatched roofs.
Both Keti and Kharo Chhan have been important towns on one of the world's nine largest delta regions.
Over the millennia, the Indus river cut some 17 major and numerous minor creeks in the region as it disgorged into the Arabian Sea in the south.
The soft mud plates between the creeks, enriched by hundreds of millions of metric tones of silt load carried down by the river each year, were the most fertile in Sindh province.
The 1921 British Imperial Gazette for Sindh cites the chief produce of the delta region as rice paddy, bananas, camels, charcoal and timber. Wool and fish products were also produced in large quantities.
In two years, parts of Keti Bandar have gone from this...
Until 1935, cargo boats regularly sailed up the Ochito Creek to Keti harbour from where they collected products for export to the Middle East.
Over the subsequent decades, an uglier face of change started to reveal itself all across the delta region.
"It came about when a huge irrigation infrastructure, built upstream in the Punjab province, started drawing water from the Indus and its four tributaries," says Abdul Majid Qazi, a former senator, engineer and expert on water issues.
... to this.
The first major irrigation canal on the Indus river system was built by the British in the Punjab in 1859. Five more canals were built between 1885 and 1914.
In Sindh province, three barrages were built between 1932 and 1962.
In 1960s, two of the Indus tributaries were apportioned to India under a water treaty, and two major dams were built on the remaining rivers with another network of canals supplying water to the Punjab.
Some experts from the Punjab dispute the view that irrigation works caused degradation of the delta, arguing that it is a natural process.
Since the mid-1980s, farmers in Punjab have carried out an aggressive campaign for a third major dam on Indus to meet the growing food and power shortages in the country.
But most experts, including those of International Conservation Union and the World Wildlife Fund, believe the delta's woes are linked to the "over-extraction" of water for agriculture.
They cite various reports of the Water and Power Development Authority (Wapda) that show that river flows into the delta decreased from around 80 million acre feet (Maf) in 1947 to less than 10 Maf during the 1990s.
During 2001-02, the flows dropped to as low as 0.72 Maf and 1.9 Maf respectively.
They believe that as the river flows diminished, the sea waters ran up the creeks and waterways of the entire delta region, turning its lush green fields into a grey, saline desert.
Since then, sea intrusion has turned millions of acres of the delta region into a vast saline wasteland, destroyed its rich mangrove forests and causing massive land erosion.
"More than 160 settlements, spread over 1.3m acres of delta, have been lost to the sea since 1970," said Nadir Akmal Leghari, the Sindh Minister for Irrigation.
Sea intrusion has also turned the ground water brackish, while the canals that used to draw water from the river remain dry for most of the year.
This has caused a widespread shortage of drinking water, and forced women to walk for miles in the hope of finding a puddle in a dry canal bed.
Meanwhile, the shrinking of pastures have caused livestock and poultry numbers in the region to dwindle from 227,000 in 1991 to less than 80,000 in 2000, a government report says.
No figures are available for population displacement, but local people say that those who have stayed on are either too poor to contemplate migration, or just don't want to leave a place where they were born and raised.
Ibrahim Soomro, the 80-year-old ironsmith of Kharo Chhan island, is one such person.
"I remember the times when this area was a lush green heaven. Then it started to change. There was salt water all around us. For a time we thought it will get better. Then we got used to it."