A protracted drought has aggravated seasonal brackish water intrusion in the Mekong Delta, significantly damaging the region's rice crop



A farmer from Soc Trang Province's My Xuyen District watering his watermelon field on March 13. The Mekong Delta is suffering from harsh drought and saline water intrusion caused by climate change and upstream hydropower dams, experts said.

Half of Banh Van Ha's rice paddy yielded empty husks this season due to an early arrival of the dry season's brackish tide.

"Saline water arrived early this year and affected my farm badly," said Ha from his farm in Soc Trang Province's Long Phu District. "Half of the grains are empty. I have no other choice than to use them as poultry feed."

Down the road, farmer Kim Hen only managed to harvest three quarters of his 2.5 hectare rice paddy.

Both Ha's and Hen's farms are situated along the Hau River a major tributary of the Mekong River in Vietnam.

Farmers all over the region have traditionally relied on seasonal floods to bring silt-rich freshwater to their wet rice paddies and farms.

Every year, as Vietnam's dry season gets underway, the flow of the Mekong River slows allowing brackish water from the East Sea to flow inland.

This year the degree of the saline intrusion appears to be getting more pronounced.

A recent United Nations report found that drought and brackish water intrusion arrived long before the annual dry season.

Sixteen provinces have hit level five drought conditions the maximum warning level for risk of forest fires.

Experts expect water shortages and salinization to continue over the next three months, according to last month's situation report on "drought, forest fires and salt water intrusion" released by the UN Program Coordination Group on Natural Disasters and Emergencies.

On March 22, the Council for Security Cooperation in the Asia Pacific Study Group (CSCAP) gathered in Hanoi for a conference on water resources security.

Scientists and experts in the region painted a rather grim picture for South East Asia's future.

"Climate change is causing worse extreme weather events, including droughts, extreme rainfall and floods, probably intensified typhoons and storm surges, and heat waves," said Koos Neefjes, climate change advisor to the United Nations Development Program (UNDP) in Vietnam.

Neefjes described freshwater use in much of the Mekong region as unsustainable and warned that it threatened national and global food security.

Meanwhile, scientists from Vietnam's Southern Institute for Water Resource Planning presented a report which charged that saline water could intrude into more than 50 percent of the river delta by the dry season of 2050.

Suffering farmers

Tra Cu District is considered the hardest hit region by saline water intrusion in Tra Vinh Province, where many farmers have given up efforts to salvage a withering rice crop.

Thach Na, a farmer in Tap Son Commune, said this is the first time he's seen a rice crop die-off on such a large scale.

On a nearby farm, Thach Thi Thai said she only managed to net a ton of rice per hectare far less than her usual harvest of between 7.5 to 9 tons.

To make matters worse, most of the rice hulls she harvested this season were empty, she said.

"Rice was badly damaged but I'll still go ahead with the harvest in the hope of making up part of my investment," she said.

In Tra Cu District, local farmers grow more than 10,000 hectares of rice but severe saltwater intrusion killed more than 70 percent the area's total crop this year, according to officials from the District Agriculture Agency.

In nearby Ben Tre Province, saltwater claimed most of the corn crop in Thanh Phu District's Thoi Thanh Commune.

All 77 hectares of corn have been attacked by saltwater, according to a representative from Huynh Dong Ha, a communal farmers association. The association claimed that local farmers have lost between 30 and 100 percent of their corn, this year.

In Ca Mau Province, saltwater has contaminated shallow ground wells, forcing thousands of people in the area to buy water, at considerable cost, from outside suppliers.

Huu Van Minh, a local official in U Minh District's Khanh Lam Commune, said that his constituents pay roughly VND116,000 (US$5.57) per cubic meter for water a sum roughly 28 times the cost paid by city dwellers.

Tang Van Tap, a Khanh Lam resident, said his family hired a company to drill four wells each deeper than the next.

In the end, the contractor failed to draw up clean water. Salinity levels reached as high as 1 percent, he said.

Adaptation

To Van Truong, former director of the Southern Institute for Water Resource Planning, said that this year's severe drought and saltwater intrusion were caused by low rainfall but the conditions have been exacerbated by upstream Chinese hydropower dams.

"The Mekong River's upstream countries pay attention to their own interest when building hydropower dams," he said, adding that conditions could get worse if China decides to divert the upstream Mekong flow to its own parched regions.

Truong stressed the importance of better resource integration among Mekong River nations, based on the tenets of regional agreements like the Mekong River Commission's Agreement on the Cooperation for the Sustainable Development of the Mekong River Basin in 1995.

Ky Quang Vinh, director of Can Tho City's Center for Natural Resources and Environmental Monitoring, advised Vietnam to improve its storage systems.

"It's not necessary to build large lakes," he said. "Each commune could use their own pond systems."

Nguyen Ngoc Anh, acting director of the Southern Institute for Water Resource Planning, said that there should be stronger dyke and dam systems to store water.

"We are planning to build two dams at Cai Lon and Cai Be and expect to complete them in 2015," he said. "There should be more dams to store water."

Meanwhile, scientists have advised farmers to shift toward more adaptive cultivation methods to accommodate rising salinity. They have pushed farmers to plant more resilient rice varietals or farm shrimp during seasons when salinity reaches its highest levels.

Tran Quang Cui, deputy director of Kien Giang Department of Agriculture and Rural Development, said that local authorities have built 17 dams to prevent saline water intrusion.