On-farm irrigation planning to reduce emissions for rice

Lack of solutions for irrigation structures to ensure water sources in the Mekong Delta

Bài liên quan

Minister Le Minh Hoan: 'The irrigation system is also a living space for people'

Assessing the current situation in the Mekong Delta, Dr. Tang Duc Thang, former Deputy Director of the Vietnam Academy for Water Resources (VAWR) and former Director of the Southern Institute of Water Resources Research (SIWRR), said that the water source to the Mekong Delta has now changed completely, with a decrease in flood season and an increase of 50% in water exhausted in dry season.

This helps to develop upstream but makes the flow regime controlled and outside the natural laws, with which humans cannot interfere, forcing them to actively adapt.

In addition, the current alluvium flowing to the delta is now severely reduced, with only less than half remaining. In the future, according to calculations by SIWRR and international agencies, by 2040–2050, the alluvium will be estimated at only about 4–6%, maybe even completely lost.

"Loss of alluvium is the biggest loss for Vietnam and the delta for the development of the Mekong River, while the water source is gained and lost, with advantages and disadvantages," said Dr. Tang Duc Thang.

According to Dr. Tang Duc Thang, at present, floods have decreased and fresh water sources for the delta in the dry season have increased compared to before, creating a significant advantage in stabilizing agricultural development if there are structural solutions to ensure water sources.

Increasing water sources in the dry season and decreasing the saltwater season created favorable conditions for developing coastal regions. However, the current shortage is the lack of solutions for irrigation structures to ensure water sources.

Dr. Tang Duc Thang said that at present, the Mekong Delta irrigation system has only been able to serve relatively stable production in normal years, but in extreme years and anomalous periods, the system has not served production with complete assurance and high reliability.

Up until now, in the middle and upper delta areas, the water source has been quite good with year-round production. Many places even produce seven crops in two years, such as Dong Thap and Hau Giang. However, coastal regions have always been dependent on water sources, while the current ones are unstable.

Specifically, in the dry season in coastal regions, the water sources are not enough, although there is a source at the top that cannot be transferred to the bottom, so the production models deployed for deep development in the lower areas cannot be done due to unstable water sources.

"If we can stabilize water sources, we will develop deeply in coastal regions, not only in fisheries but also in diversified agriculture, especially in fruit and rice sources. When grown in a coastal region with low salinity, that source of fruit is priceless, and rice will also be more delicious than in the upper areas, "said Dr. Tang Duc Thang.

Dr. Tang Duc Thang suggested that, in the Development Strategy, the Ministry of Agriculture and Rural Development (MARD) should increase fresh water supply and stabilize saltwater sources for coastal regions. At the same time, strengthen water sources for two regions, including the South of the Cai Lon River (Ca Mau, Bac Lieu, Kien Giang) and the Southeast of Dong Thap Muoi (Dong Thap, Long An). "These are important regions that need to be solve the problems of water sources to stabilize production and enhance the industry’s deep development in the Mekong Delta," he said.

Proactive management of internal water sources with structural and non-structural solutions

At the meeting with SIWRR led by Minister Le Minh Hoan last week, Director of the Department of Water Resources Nguyen Tung Phong said that disaster prevention and irrigation planning have been approved by the Prime Minister under Decision 847 dated July 14, 2023. This is an important basis for the irrigation industry to have the opportunity to access and promote the existing results and foundations, especially in the Mekong Delta, which has many challenges.

Therefore, Director Nguyen Tung Phong proposed SIWRR review the irrigation planning and structural solutions, especially the Mekong Delta irrigation planning, to meet the target and think of transforming from serving into providing multi-purpose services.

Regarding water source security for the Mekong Delta, according to the Director of the Department of Water Resources, this is a big issue, especially in taking the initiative on internal water sources with structural and non-structural solutions. For irrigation in general and large multi-purpose irrigation structures, investments have been made basically, but 60% of the irrigation efficiency is in the field.

If implementing 1 must - 5 decrease, 3 increase - 3 decrease without irrigation system, irrigation structure, and on-farm irrigation planning, the irrigation regime will certainly not be guaranteed to reduce emissions for rice in the Mekong Delta.

Mr. Nguyen Tung Phong suggested that SIWRR pay attention to the issue of field re-planning and multi-purpose services, especially reducing emissions with the World Bank's 1 million-hectare rice project.

"This year will definitely have El Nino; the rainfall will decrease by 20% compared to many years. The problem of saltwater intrusion will appear earlier, peaking from February to May 2024. Therefore, The Department suggests SIWRR continue to promote and improve the capacity of forecasting and warning drought and saltwater intrusion," said Mr. Nguyen Tung Phong.

Regarding the problems of river and coastal erosion, coastal management, river and coastal erosion forecasting capacity, etc., it is necessary to develop integrated management solutions for both social and economic issues and identify areas of fundamental and long-term nature, including the issue of population arrangement.

Minister Le Minh Hoan suggested that, in the coming time, the SIWRR’s irrigation scientific research will not only solve the problem of ensuring water sources for production but also create livelihoods for local people and an economy for the locality.