VietNamNet Bridge – Severe, frequent droughts are seriously threatening water security, Truong Dinh Du, formerly with the Viet Nam Institute for Water Resources Development, tells Nong Thon Ngay Nay.

Illustrative image. – File photo

Droughts and saline intrusion have become more and more serious and complicated, affecting large areas in the central and southern regions during the past several years, particularly this year. Is this due to an abnormal weather situation?

Based on data that the IWRD had announced recently, severe drought and saline intrusion have become a serious natural issue that is threatening the whole Mekong (Cuu Long) Delta and the south-central region, with water flow deficiency in some areas pegged at as high as 80 to 90 per cent, which is the highest ever in history. This is a really strange weather situation.

Meanwhile, in the Red (Hong) River Delta, between 3 and 5 billion cubic metres of water are discharged annually from the Hoa Binh reservoir to support irrigation in the delta.

This clearly proves that national water security is being threatened at an alarming rate and is effecting not only the country's socio-economic development, but also its political achievement.

During many environmental workshops held recently, scientists and environmentalists had raised water security as one of the most urgent issues that needs an immediate solution, which is focused on preserving and recovering the water flow.

Weather forecasts have warned that this year's drought season would last until September. Warnings have also been given about the main cause being the impact of ENSO or the El Nino Southern Oscillation. Is this purely a consequence of natural climate change?

There are different causes for water deficiency in different areas. The causes obviously and commonly include not only an impact from natural climate change, but also an increase in human demand for water for production and daily life.

In the Tay Nguyen region, for example, the rapid development and expansion of coffee cultivation areas has surpassed 20 per cent over the planned target, while there is no target set for irrigation. Others agricultural and industrial sectors in the region are also suffering the same fate.

However, a more serious problem is the rapid decrease in forest cover, which has resulted in high evaporation rates and deficiency of water flows.

In the central provinces, where there are high slopes facilitating water flow, droughts come very quickly and right after the floods, while in the Cuu Long Delta, water reservoirs have been recognised as an effective solution for preventing drought.

What are the long-term consequences of water deficiency?

Scientists have warned that prolonged water shortage in the Central Highland (Tay Nguyen) and Cuu Long (Mekong) Delta will lead to changes in the entire cultivation pattern, with the land area being narrowed or destroyed due to an increase in the sea level and desertification.

Water deficiency will lead to various social and economic issues, including the prevalence of poverty, unemployment and national security being threatened.

As I have mentioned before, water is a very important natural resource, and it needs adequate investment and consideration. A boost in investment and in the construction of reservoirs or dams to protect water flows during the past several years can still not meet demand for water resource preservation.

Do you mean the current measures that help prevent drought are not comprehensive solutions?

There should be different solutions relevant for different areas. In the Cuu Long (Mekong) Delta, for example, water reserves depend much on outside flows and thus there should be projects for crossing the river to preserve fresh water and preventing saline intrusion. For the longer term, there should be fresh water reservoirs in the sea like some countries have created.

In the Tay Nguyen and central provinces, along with the river crossing projects, new large-scale reservoirs should be built up connecting the current smaller ones to make up a complete system of inter-reservoirs.

Moreover, these regions also need to change their cultivation scheme. These plants grow rapidly and need less water so are more favourable for these regions.

You have suggested outstanding measures for drought prevention, including the crossing river and sea guarding ideas. However, many scientists have cautioned against their feasibility due to their high cost and high risk. Can you explain that further?

Our river crossing initiative, which includes setting up barge dams to preserve river water, in fact, has been highly appreciated by many experts and has been put into implementation in many areas across the country. The largest project is on the Thao Long River in Hue City.

It is true that it needs more consideration, but I can say that our initiative could be implemented more effectively all over the country as the cost for construction of barge dams in this initiative is much less than the older dams.

In the Hong (Red) River Delta, if our project for building barge dams for water preservation was approved by the government, there would be no need to discharge an annual water resource of 3 to 5 billion cubic metres for irrigation and electricity production. Actually, 70 per cent of such water would be wasted and go to sea.

VNS