Northern region at risk of desertification

Professor ASM Woobaid Ullah

Mindless withdrawal of river water and unbridled extraction of groundwater are to blame, Professor ASM Woobaid Ullah of the Delta Research Centre at Dhaka University tells New Age

by Shahidul Islam Chowdhury

MINDLESS withdrawal of river water and unbridled extraction of groundwater have put the northern region at a risk of desertification, says Professor ASM Woobaid Ullah, director of the Delta Research Centre at Dhaka University.

However, due to fund constraints, the centre, which came into being in 1991, has not been able to conduct any in-depth research into the formation of land in Bangladesh and desertification, he said in an interview with New Age on Tuesday.

The largest ‘living’  delta and its geological phenomena provide a large and rich area for geological research, the kind of research necessary for infrastructure design, risk reduction, and resources optimisation, which can ensure the well-being and prosperity of over 160 million residents of the delta., he added.

Excerpts:

Bangladesh is called a living delta created by silt carried by rivers. Observers often say that the rivers are dying. What would be its impact?

It is true that Bangladesh is a living delta as rivers flowing through the land have carried silt for millions of years. Most of the 54 major rivers have entered into Bangladesh, an almost horizontal floodplain, from mountains and hills in upper riparian countries including India, Myanmar and China.

Silt carried by rivers becomes deposited on riverbeds. Shoals are created in this process.  Now many rivers are dying due to natural and human interventions.

Unbridled and unplanned human interventions, including constructing dams, embankments and roads and encroachment into the rivers, in both upper and lower riparian countries, have expedited the process of siltation drastically reducing the river flows and the capacity of a river to carry silt.

Most of the rivers are flowing from north to south while most of the roads are constructed from east to west obstructing the riverbeds.

What is the magnitude of human interventions? Is there any statistics on how many structures, irrespective of their size, have been erected in the past 50 to 100 years?

There is no specific information about the number and size of infrastructures on rivers. It is, however, understandable that people becomes both beneficiary and victims of human intervention.

Rivers waters are used in farms and industries. Unplanned and inappropriate obstructions of river flows, on the other hand, also create havoc through creating water logging, floods and erosion of habitats.

How do you assess the impact of the surge in construction of large barrages and dams on the rivers in upper riparian countries?

Water is a basic right. Many countries in different continents share common rivers with neighbouring countries. India is a huge country. They need water. But they also need to understand that no authority or law allows monopoly of a country on a common river or water body.

Unilateral withdrawal of water at the upstream will jeopardise relations between the two countries.

The governments of Bangladesh and India are now talking about holding a joint study on the construction of the Tipaimukh Dam on the river Barak that carries water for Surma, Kushiyara and Meghna rivers in Bangladesh. A group of experts believe it should be an international study as there is trust deficit between the two countries. What is your opinion?

I do not see the necessity of involving third party experts at the beginning of the process. Scientists, researchers and experts are expected to provide unbiased data, analysis and recommendations for consideration of the political authorities in respective side. So, at the initial level, the two countries can hold a joint study keeping experts from both sides involved in the process.

However, the two countries can seek international support on disputed issues, if there is any.

Successive governments have implemented many development projects that also include intervention in rivers. People’s perception is that, in most of the cases, the authorities concerned do not go for a quality impact assessment. Is such perception right?

It is true many projects were implemented without conducting impact assessment in the past. The authorities concerned have, however, conducted impact assessment for most of the large and medium projects implemented in the past 20 years.

Do you believe that quality of impact assessment was ensured in most of the cases?

In most of the cases the authorities concerned accept the assessment reports. The Department of Environment can give objection if it deems an assessment faulty.

Is the environment department really capable of evaluating impact assessments done across the country?

It is their responsibility. They must perform.

Each delta holds some specific characteristics. Do you observe any major change in the formation of land in Bangladesh?

With increasing withdrawal of rivers waters in both upper riparian countries as well as inside Bangladesh, the flow of sweet water is constantly decreasing. As a result, salinity is increasing in many parts of the country.  

Recently we have noticed salinity at subsoil level in northern areas.

Has brackish water from the Bay of Bengal reached northern districts?

I do not think so. Many parts of the central districts were coastal areas several thousand years ago. The Bay of Bengal has had shifted southward with rapid siltation of rivers and formation of lands in the southern delta. Brackish waters, which could not match with the pace of siltation and formation of lands, have remained trapped for years at the subsoil level in many central districts.

Now with decreasing groundwater level and rivers flows, we have been getting signs of salinity at the subsoil level in that locality.

How do you see the pace of ‘shifting delta’? 

The major rivers, including the Ganges, the Brahmaputra and the Meghna, formed the largest river delta in the world leaving behind over three to four billion tonnes of sediment each year. The rivers, which are also carrying sediments to canyons into the deep sea, have been slowly changing their courses as well as the landscape.

Does groundwater extraction have any impact on formation of delta?

People depend on surface water as well as groundwater for living. With decreasing flow of rivers water, dependency on groundwater extraction increased significantly. Over extraction of groundwater may lead to landslide and intrusion of brackish water inside Bangladesh.

Do you see any sign of desertification anywhere in Bangladesh?

With decreasing availability of sweet water due to declining river flows and less rain and mindless extraction of groundwater, the northern region of the country is at the risk of desertification.

What is the state of research on formation delta and desertification?

There are some research works on the river Jamuna.

Is there any basic research?

There is dearth of funds for research in general, in this field in particular. The Dhaka University authorities allocate only Tk 2 lakh for the Delta Research Centre every year. The University Grants Commission provides Tk 1 lakh for the centre.

In this situation, we can allocate only Tk 30,000­–40,000 for a research work although we understand that it is difficult for a researcher to conduct quality research with this budget.

What is the use of keeping the centre open unless you can conduct substantive research?

We have kept it open with a hope for better research in future.