Experts on Wednesday discussed the merits and demerits of at least four dyke and sluice gate solutions that have been proposed to help HCM City deal with increasingly frequent flooding that it has faced over the past few years.
by Phuoc Buu
HCM CITY —
|This street in HCM City's District 2 was one of many flooded during the rainy season last November. More than 900,000 of the city residents were affected by the swirling water. One local solution proposed is to build a flood prevention system by upgrading irrigation facilities. — VNA/VNS Photo Anh Tuan |
They said the city should carefully consider its choice or combinations of choices before taking a decision on the issue.
One local solution that has been proposed is to build a flood prevention system in the city itself by upgrading its irrigation facilities and building small dykes at the estuaries of rivers and canals to block high tide inflows.
The second solution calls for a master project that would close estuaries and efficiently operate reservoirs in the upper reaches of Sai Gon and Dong Nai rivers.
According to the HCM City Steering Committee for Flood Prevention and Control, the city is investigating four options of sluice and open dyke construction in parallel with a Japan International Co-operation Agency (JICA) supported project to upgrade its irrigation system.
The first option, proposed by the Ministry of Agriculture and Rural Development, is an open dyke system with 12 small sluice gates that borders the city's coast.
VN launches climate-change strategy
HA NOI – The Ministry of Natural Resources and Environment (MONRE) has launched a national climate change strategy to deal with rising sea levels.
At the launch ceremony in Ha Noi on Wednesday, Minister Nguyen Minh Quang said the Vietnamese Government had ratified the UN Framework Convention on Climate Change and the Kyoto Protocol and was completing legal documents on the control and mitigation of natural disasters.
The strategy, which was approved by the Prime Minister on December 5, 2011, comprises six components with 10 strategic tasks to deal with climate change. It outlines overall objectives, priority projects to be implemented in 2011-2015, and plans for 2016-25, as well as objectives for 2050, with a vision to 2100. It also identifies strategic tasks to cope with global climate change.
Director of the Viet Nam Institute of Meteorology, Hydrology and Environment Dr Tran Thuc said MONRE had completed the plan in 2009 based on estimates of greenhouse gas emissions and the global climate change scenario by the Inter-Governmental Commission on Climate Change.
Also at the event, the international community highlighted the Vietnamese Government's efforts to cope with global climate change and pledged continued financial and technological assistance in the field.
The Ministry of Natural Resources and Environment has also organised discussions on increasing co-ordination in coping with and implementing policies on climate change and financial issues arising from global warming. Viet Nam will also enhance awareness of climate change through education and training programmes, as well as scientific and technological research. — VNS
This plan has been criticised as focusing solely on controlling vulnerability to floods and lacking measures to tackle other flooding risks.
The city has come up with a second option that adds several variations to the ministry plan to reduce the risks. Details of this option were not immediately available.
Prof Nguyen Tat Dac of the HCM City University of Industry has recommended building a 1km-wide sluice on the 3-km Soai Rap estuary of Dong Nai River. With this sluice, the number of sluices planned by the ministry would be reduced from 12 to six.
Dac's recommendation is considered the third option.
The last one is a 23-km long sea dyke that would be extended from one point on the coastline near Vung Tau City to another point on the coastline off Long An Province. This idea was mooted by Dr Dao Xuan Hoc, deputy Minister of Agriculture and Rural Development, early last year.
Speaking at yesterday's seminar, Peter Kerssens, a Netherlands flood control expert, said research indicated that the sluice recommended by Prof Dac "could prevent a large amount of tide (inflow) to the city."
The sluice will block only part of the Soai Rap estuary and will not block the Long Tau estuary. These two estuaries are the largest on the city coast and crucial to the city's seaport development plans as well as natural water flows.
Guus Sutmuller of the Netherlands Royal Haskoning, an architect and engineering constancy firm said he preferred the first option proposed by the ministry. "This plan is probably the best solution for protecting the urban areas in the city until 2025," he said.
Nguyen Ngoc Cong, deputy director of the Steering Committee for Flood Prevention and Control, said the seminar was part of a project to formulate a master strategy for flooding prevention in the city.
The project has received US$2 million in assistance from the Netherlands Government and is technically supported by Dutch firms like Royal Haskoning, Deltares and DHV.
Experts at the seminar agreed that the city should take care to choose the optimal solution for flood prevention because it affects residents' daily lives, the environment and socio-economic development.
Hoang Van Thang, deputy Minister of Agriculture and Rural Development, said: "Flood prevention in HCM City is an urgent task but it also needs a long-term vision. A very important thing is that we should change our outlook from controlling flooding to controlling the vulnerabilities caused by natural disasters". — VNS