Northern region drying up amid freshwater loss

Freshwater, both surface and
groundwater, from northern Bangladesh has been declining steadily for the past
two decades, reveals a new global study.
The research,
led by Arizona State University and published in Science Advances, analysed
over 20 years of satellite data.
Titled "Unprecedented continental drying, shrinking
freshwater availability, and increasing land contributions to sea level
rise", it found that 101 countries in the northern hemisphere have
suffered unprecedented freshwater loss since 2002, driven by climate change,
unsustainable groundwater use, and extreme droughts.
"Bangladesh
is among the countries where freshwater has been declining for over the last
two decades. Every year, it is reducing by 2.5mm–10mm. This is very alarming
for us," said Md Rayhan, a Bangladeshi PhD student at Arizona State
University who contributed to the study.
Using GRACE/FO
satellite data from 2003 to 2024, the study tracked total water storage (TWS)
across the Ganges-Brahmaputra Basin, which covers much of Bangladesh. It found
a consistent decline over 21 years.
The North-West
and North-Central regions appeared in reddish shades on satellite maps, showing
annual TWS losses between −1 and −2cm.
"These TWS
patterns show that over the past 21 years, parts of Bangladesh within the
Ganges-Brahmaputra Basin have experienced long-term declines in water storage.
"This water
loss is not just a short-term change, but a long-term trend that has remained
consistent even as more data has been added to the study. Scientists call this
kind of steady, ongoing change a 'robust' trend," Rayhan said.
"It means the drying pattern in Bangladesh has been
strong and consistent, not just due to random weather or short-term events. The
study shows that Bangladesh is one of the places in the world where water
storage has been going down consistently over the study period."
As the water
level continued to decline, last month, the government announced fifty unions
in 26 upazilas of Rajshahi, Chapainawabganj, Naogaon and Chattogram as severely
water-stressed. Of the unions, 47 are in Rajshahi, Chapainawabganj, and
Naogaon, while three are in Chattogram's Patiya upazila. The government is
working on preparing a guideline to restrict water abuse in those areas.
A GLOBAL CRISIS
The study warns
that nearly six billion people in 101 countries -- about 75 percent of the
global population -- have lost freshwater over the past two decades.
Researchers
found that 68 percent of land-based water loss came from groundwater alone,
contributing more to sea level rise than the Greenland and Antarctic ice sheets
combined.
"These
findings send perhaps the most alarming message yet about the impact of climate
change on our water resources," said Jay Famiglietti, the study's
principal investigator and a Global Futures Professor at ASU's School of
Sustainability.
"Continents
are drying, freshwater availability is shrinking, and sea level rise is
accelerating. The consequences of continued groundwater overuse could undermine
food and water security for billions of people."
Lead author
Hrishikesh A Chandanpurkar added, "Glaciers and deep groundwater are like
ancient trust funds. Instead of using them sparingly during crises such as
prolonged droughts, we are depleting them without replenishment, edging towards
an imminent freshwater bankruptcy."
According to the
United Nations, by 2030 the world will need at least 30 percent more water, 45
percent more energy, and 50 percent more food.
Climate change
is compounding this crisis in Bangladesh, as declining Himalayan meltwater
inflows and sea level rise are already causing saltwater intrusion in northern
districts, further reducing both surface and groundwater availability.
As a downstream
nation, the country also faces a regional disadvantage. Upstream extraction in
India and Nepal continues to affect flows, yet no effective cross-border
water-sharing agreements exist. This imbalance worsens seasonal stress across
the country.
GROUNDWATER EXTRACTION
The country
extracts about 32 cubic kilometres of groundwater every year, 90 percent of
which is used for irrigation and 10 percent for domestic or industrial use.
"Due to
such over-extraction, groundwater is being contaminated with salt and heavy
metals. Twenty-four percent of lands are now exposed to extremely elevated
arsenic, salinity and groundwater depletion hazards," said Dr Anwar Zahid,
former director of groundwater hydrology at the Bangladesh Water Development
Board.
"We've
observed that groundwater levels in urban areas, particularly Dhaka and the
Barind Tract, have been declining permanently at an alarming rate. This implies
that the water level is not being recharged even after monsoon. With increased
extraction, fluctuation of groundwater levels has also increased with
time."
A 2019 study
found Bangladesh losing groundwater at an average rate of 8.73 millimetres per
year. In 2006, the number of shallow pumps was 11.8 lakh; by 2019, it had risen
to 16 lakh. Dhaka Wasa alone pumps about 3.3 million cubic metres of water
every day -- enough to fill 20 Mirpur stadiums.
For families in
Dhaka, tube wells are increasingly unreliable, forcing many to rely on costly
water deliveries.
In Keraniganj,
villagers face water scarcity for months. "From March to June, we get no
water," said resident Akhil Chandra Das.
Farmers also
struggle. "All the farmers use groundwater to irrigate their paddy field
because it is cheaper than surface water. To irrigate one bigha [33 decimals]
of boro, it takes Tk 3,000 for a season. But to irrigate with surface water, we
need to hire day labourers or install shallow machines which are even
costlier," said Shimul Ali, a farmer from Rajshahi's Paba upazila.
"However,
since it rained a lot this year, we didn't need to irrigate our fields."
Meanwhile,
coastal villagers face salinity intrusion in drinking water, leaving them
dependent on rainwater harvesting or unsafe sources.
DRAWBACKS AND SOLUTIONS
"The
population is increasing every year, and so is the demand for freshwater,
particularly for irrigation and industry. Naturally, our natural water storage
is shrinking day by day," Dr Zahid told The Daily Star.
He stressed the
need to shift towards surface water and rainwater retention.
Large-scale
rainwater harvesting has not materialised, while chronic urban waterlogging
prevents effective recharge. Experts warn that without urgent updates and
enforcement, water governance will remain inadequate.
A 2023 global
study published in Nature and supported by NASA's GRACE satellite data shows
Bangladesh losing significant amounts of freshwater annually.
According to the
World Bank (2021), groundwater levels in parts of Dhaka are dropping by nearly
2–3 metres every year, threatening long-term water security.
This crisis is
further compounded by salinity intrusion in coastal regions and reduced
dry-season flows of major rivers such as the Ganges, Brahmaputra, and Meghna.
"Without
urgent interventions in sustainable water management, Bangladesh's freshwater
decline could severely impact agriculture, public health, and overall
resilience to climate change," warned urban planning expert Ahmed Mukta.















