VIETNAM: Employing improved technology against typhoons, flooding

Photo: Brennon Jones/IRIN

Truong Thi Hanh (left) with neighbours at the Vinh Hau residential cluster. She and her family were forced to flee in a boat in the dark when a typhoon eroded the bank and their house was destroyed

AN GIANG, 19 August 2008 (IRIN) - Vietnam is experiencing more frequent and powerful typhoons and floods, and the UN Development Programme (UNDP) Human Development Report 2007-2008 has said as many as 22 million Vietnamese could be displaced if sea levels rise by one metre.

The government is collaborating with UN agencies and the humanitarian community, as part of its overall disaster preparedness plan, to design effective ways to hold back the increasingly damaging storm surges and flood waters that wreak havoc on vulnerable rural communities.

From June to November, most regions of the Mekong Delta face three threats of flooding, according to the Department of Agriculture and Rural Development (DARD) of An Giang Province (southeast of Ho Chi Minh City and bordering on Cambodia): heavy volumes of upstream Mekong water that sweep down into the delta; tidal flooding where water from the South China sea surges into the area; and flooding caused by continuous heavy rainfall over the delta region.

Flood-proofing projects

One model flood-proofing project is being implemented in the Mekong Delta by the People's Committee of An Giang Province and DARD.

It has US$182,250 of funding and other support from the US Agency for International Development (USAID), with UNDP being the facilitating agency. The project involves the construction - at two residential clusters - of steep embankments that use innovative technology to protect the communities from flooding.

Photo: Brennon Jones/IRIN

The flood-proof embankment at Donh Kenh Ba residential cluster is constructed with a geosynthetic material sandwiched between layers of earth and covered with large stones. The embankment will protect the 140 families who live there

Residential clusters are sites where the government has in the past decade been relocating to higher ground families who have lost their homes and possessions, even crops. As of 2006, according to DARD, in An Giang, 57 percent of the households in the province - nearly 17,000 families in all - had been relocated to such clusters.

Two model project sites - Vinh Hau residential cluster, which has 104 families, and Donh Kenh Bay residential cluster, which has 140 families - were chosen after some months of consultation with farmers and local authorities. In each site, between February and May 2008, steep embankments some 500 metres long and three metres high were constructed using an innovative technology that consists of sandwiching "geosynthetic material" (strong textiles) between layers of earth and covering it with a heavy stone overlay.

Geosynthetic material

"In other parts of Vietnam, such geosynthetic material has been used since 1997 to build river dykes and reinforce roads, but not yet in the southern part of the country for such embankments," Nguyen Phuong Dong, a geotechnical engineer and consultant to the project, told IRIN. "What the fabric does is allow the water to pass through but the soil to remain firmly in place."

"The two residential communities in which the embankments were built are amongst 200 in An Giang Province alone that need similar flood proofing." Dong said.

The embankments will only get their true test in the coming months when the typhoons and heavy downpours arrive, but residents are clearly pleased they have been built.

Nguyen Thanh Phuong, a 53-year-old farmer living at the Donh Kenh Bay residential cluster and whose former house had been destroyed by a typhoon, told IRIN: "I am glad to see this embankment. Now there will be no more landslides or erosion; we are safe."

At the Vinh Hau residential cluster, Truong Thi Hanh, who is in her 60s, told IRIN: "Our first house, just near here, was washed away when the embankment collapsed... We had to flee at night in a very small boat with our two children who couldn't swim. It was terrifying… This new embankment makes my family feel safe."

Photo: Brennon Jones/IRIN

Nguyen Thi Gai of Vinh Thuan commune, Vinh Hau village, stands in front of her house, which sits well above historic flood water levels on a model platform constructed using geosynthetic material and reinforced construction

Model raised platform

As part of the flood proofing project, a model raised platform for a house was constructed in Vinh Thuan commune, Vinh Hau village, also using geosynthetic technology. "I feel secure now because the platform keeps the house well above flood level - even the highest in memory, which was in 2000, the house owner, Nguyen Van Lam, told IRIN.

The vice-director of DARD and flood proofing-project director Do Vu Hung told IRIN with some pride: "The programme is helping us reduce our vulnerability to disasters. We are piloting new and effective construction."

According to Hoang Thi Phuong, UNDP project assistant, "There are two components to the project. One is the actual construction and the second, which is equally important, is demonstrating the enhanced flood-proofing technologies."

"As part of the project," Pham Van Le, the head of DARD, told IRIN, "provincial and local authorities and some 200 villagers have now been trained in constructing embankments and raised platforms using geosynthetic material."

Handbook

A handbook is also being created to raise community awareness about the technology. It will be distributed within An Giang and to vulnerable neighbouring provinces. In mid-September, a regional workshop will be held in An Giang to demonstrate the flood-proofing technologies to provincial and local authorities, humanitarian agencies and donors.

"With the workshop, we will be able to increase the capacity of others to deal with flooding," Pham Van Le told IRIN. "It will be like a breath of fresh air to people in vulnerable communities, in flood-prone areas."

bj/cb