Vetiver grass offers a sustainable, green, and inexpensive means to tackle hill erosion
Thai Princess Maha Chakri Sirindhorn has inaugurated a vetiver grass demonstration centre at Tigerpass as part of a joint Bangladesh-Thailand project to prevent hill erosion in Chattogram.
She also planted the grass on the slope of Tigerpass hill on Wednesday.
The Chittagong City Corporation has earmarked four hills – Burma Haji Pahar, Khulshi Pahar, and hills on both sides of the Tigerpass intersection – for vetiver grass plantation.
Vetiver (vetiveria zizanioides), a clumping grass without stolons or rhizomes, is known for its ability to reduce siltation and stabilize soil. Its non-fertile seeds ensure that the plants will not spread beyond where they are planted.
Engineers liken the vetiver root to a “living soil nail” with an average tensile strength (used to describe the extent to which something can stretch without breaking) of 1/6 mild steel. The deep root system makes vetiver extremely drought tolerant and difficult to dislodge.
The inaugural ceremony was attended by the Minister of Environment, Forests and Climate Change Anisul Islam Mahmud, CCC Mayor AJM Nasir Uddin, Buet Prof Dr Md Shariful Islam, Thai Ambassador to Bangladesh Panpimon Suwannapongse, Bangladesh Ambassador to Thailand Saida Muna Tasneem, CCC Chief Executive Officer Md Shamsuddoha, Chattogram Deputy Commissioner Elius Hossain, Chattogram police chief Noor E Alam Mina, and representatives from Chaipattna Foundation.
Mayor Nasir said the centre, the first of its kind in Bangladesh, has been set up to impart training and host workshops for the widespread use of the grass.
“Waterlogging has turned out to be a major problem for the port city due to soil erosion and landslides,” he said, describing how soil eroded from the hills after torrential rains clog the drains and nearby water bodies and trigger water stagnation.
“The practice of dumping solid waste into the drains and canals has made matters worse,” he added.
Nasir said the Thai princess, after learning about waterlogging, expressed her willingness to provide financial and technical assistance through the Chaipattna Foundation to address the perennial problem.
“The vetiver grass has also proved successful for addressing soil erosion in Thailand. Taking a cue from there, we are going to the cover the four major hills of the port city with the grass to control slope erosion,” he said.
If the pilot project yields positive results, the CCC plans to plant the grass on the hill slopes of the city on a large scale. The Ministry of Environment, Forests, and Climate Change has promised to allocate Tk2 crore for the pilot project.
‘Simple and economic method’
Prof Islam, who is providing technical assistance to the CCC in this regard, said: “Vetiver is a miracle grass. It is being used as an efficient bio-technology for slope protection in many countries for its special attributes like longer life, strong and finely structured root system, and high tolerance of extreme climatic conditions.”
The Buet teacher has been conducting research on vetiver for over a decade.
“Many tropical countries have been using it as a simple and economical method to conserve soil. It slows the water velocity and stabilizes steep slopes. The grass can survive extreme weather conditions ranging from -14 degrees Celcius to 55 degrees Celsius,” he added.
The extremely deep and massively thick root system of vetiver binds the soil and at the same time makes it very difficult for it to be dislodged under high velocity water flows.
This deep and fast growing root system also makes vetiver drought tolerant and highly suitable for steep slope stabilization.
Prof Islam said: “Vetiver grass is available in Bangladesh. It can grow on both silt and clay soil. Apart from saline soil, the grass can even grow in heavy metal contaminated soil.
“It is not a weed. This grass is non-competitive with adjacent crops and cost-effective. So, vetiver grass plantation could be a sustainable, green, and cheaper bio-engineering solution to slope protection.”