VietNamNet Bridge – The 4% salinity has encroached by 40-50 kilometers far into the Mekong Delta. Hydrologists say the saltwater intrusion this year comes too early, which is unusual and unprecedented.

The most severe in history

In Soc Trang province, drought and salinity both have seriously affected the agricultural production, damaging tens of thousands of hectares of the winter-spring rice fields in the areas bordering Bac Lieu province. More than 20,000 hectares of rice fields in some communes along the Long Phu – Tiep Nhat canal have been in the danger of getting suffered from the drought and saltwater intrusion.

Local authorities have affirmed that the saltwater intrusion this year may be the most severe in the history, following the last small flood season and the strong northeast wind.

Since mid February 2013, it has been unable to find fresh water at the river mouths, just 30 kilometers from the sea. Meanwhile, scientists have warned that in March, April and May, the coastal areas may lack freshwater for daily lives.

According to the Ben Tre provincial Center for Hydrometeorology Forecast, on Cua Dai River, the salinity has reached 27 ‰ -30 ‰ in Binh Dai district, 13 ‰ -16 ‰ in Loc Thuan, 2 ‰ -3,5 ‰ in Long Hoa.

On the Ham Luong River, the salinity is as high as 27 ‰ -30 ‰ in An Thuan, 0.1 ‰ -1 ‰ in Vam Mon. Local authorities have been hurrying taking actions to protect over 64,500 hectares of the winter-spring crop rice fields and 25,000 hectares of aquatic ponds.

Learning to adapt and live in climate changes

Under the climate change and sea water rise scenario, if the sea water rises by 30 cm, 50,000 hectares of agricultural land in Mekong Delta would suffer from the saltwater intrusion, which means that the delta would lose up to 120,000 tons of rice.

In the worst case, the mangrove area may be larger of up to 500,000 hectares, farmers would lose one million tons of rice.

In fact, local farmers have been familiar with the salinity intrusion over the last many years. Coping with the salinity intrusion has always been very important for the survival of the agricultural production in the area.

Experts have suggested changing the crop seasons, cultivation techniques and plant varieties, and utilizing the plant varieties with high salinity resistance, emphasizing that these are the measures to optimize the use of agriculture land.

Pham Thanh Vu, MA, from the Can Tho University, believes that the rotational rice cultivation & shrimp hatchery model should be applied to the areas with the long salinity intrusion time and high salinity. The areas with the salinity intrusion duration of more than seven months a year should turn into shrimp farming areas.

Meanwhile, the 3-crop would still be applied in the areas which have embankments to prevent the salt intrusion, or have irrigation works to provide fresh water.

Diversifying plantations to make it suitable to the different conditions of the land areas has been considered the long term solution to get adapted to the climate change. In Soc Trang province, for example, farmers have been using the high salinity resistance rice varieties in the rotational crop model. However, experts say the model would be helpful in the areas with the low land salinity.

It may happen that when farmers try to rescue rice fields by blocking water inlet sluice, this would lead to the lack of salt water for shrimp.

NLD