Sunday, December 22, 2013

Irrawaddy Dwindling: Delta Losing Land To Rising Sea

(News article and photo direct from the Eleven Media on December 17, 2013.)

Irrawaddy River and the Delta.
Our great river Irrawaddy is flowing sluggish and thus carrying down fewer tons of silt downstream every year and the disturbing result is clearly seen in the Delta for well over two decades. Our seemingly ever-expanding Irrawaddy Delta has stopped expanding and even losing average five square-miles per year to the rising sea since 1990.

According to Professor Maung Maung Aye the Riverine Geological Expert holding a seminar at the “Public Forum for Strategic Environmental Valuation of Irrawaddy River Basin” held at Rangoon University’s Judson (Yuu-da-than) Centre, Irrawaddy Delata is losing 13 Sq-Km (5 Sq-miles) a year average from the dual causes of lower flow from Irrawaddy and rising sea level in the Gulf of Martaban (Moat-ta-ma).

According to Professor Maung Maung Aye his intensive studies of Irrawaddy Basin and the Delta shows that between 1925 and 1989 Irrawaddy had had a high rate of silt delivery to the Delta and the result is 8.7 Square Km per year average creation of new land in the Delta. But after 1990 till 2006 the rate of silt delivery from the dwindling Irrawaddy slowed down substantially while soil erosion from the rising sea level had accelerated.

“Just from the Delta’s land-area point of view there were two distinctive periods. From 1925 to 1989, because of silt settling from the Irrawaddy, the land area in Delta increased average 8.7 Sq-Km a year. Sea was basically pushed back down further south. But later the trend reverses and sea has been eating away the land from the southern end of Irrawaddy Delta since 1990,” said Professor Maung Maung Aye.

“Right now we are in the period of sea eating away the land. It started from 1990 and by 2006 the rate of land erosion becomes so much greater. It is like a never-ending battle between the giant river and the sea. From 1925 to 1989 the high-flowing river was winning and that was the only reason our Delta was expanding steadily. But, right now the sea has been winning as the river flow is gradually dwindling and the result is the Delta retreating back at the average rate of 13 Sq-Km a year,” added Professor Maung Maung Aye.

The Confluence of Irrawaddy  and Myitsone Dam.
“In other words, the quantity of river water reaching to the Delta is becoming less and less every year since 1990. The main reason is the building of so many flow restrictions like dams and river-water pumping stations upstream along the Irrawaddy. Not just the main river but also the tributaries flowing into Irrawaddy. Chin-dwin River is one of them. Right now there is not a single dam on the Irrawaddy yet, but her tributaries have so many dams on them. Natural flow has been severely disturbed by all those restrictions,” continued Professor Maung maung Aye.

He also commented that since there are so many foreign-direct-investment projects starting on the valley plain of Irrawaddy their environmental impacts should be studied and the suitable implementations to reduce that impact should be included.

In recent years the average yearly-silt-delivery-rate of Irrawaddy from the Confluence (Myit-sone) to Mandalay is 32 million tons and from Mandalay to Henzada (Hin-tha-da) is 120 million tons.

Vast Irrawaddy Delta.
Monthly water surplus-or-deficit in the River Irrawaddy.
Suspended Myitsone Dam site.
Myitsone Dam Project model.
Related posts at following links:
Irrawaddy Waters and Ne Win's Gold Trees