Prospects and challenges in development of ground water resources of bangladesh

Prospects and Challenges in
Development of Ground Water Resources
of Bangladesh
GROUP 07

Groundwater is an important resource for livelihoods and the
food security of billions of people, and especially in booming
Asia’s agricultural economies. Globally, groundwater provides
approximately 50% of current potable water supplies, 40% of
the industrial water demand, and 20% of the water used for
irrigation (UNESCO 2003).
The Groundwater Information Center, California (2003) reported
that although surface water and groundwater appeared to be
two distinct sources of water but in fact they are not. Surface
water and groundwater are basically one singular source of
water connected physically in the hydrologic cycle.
Therefore, Development of Ground Water Resources of
Bangladesh is an important issue.
INTRODUCTION

OBJECTIVES
1. To know the current status of Groundwater in Bangladesh
2. To find out the challenges of Groundwater problem in Bangladesh
3. To know the adaptation against Challenges of Groundwater

Groundwater is the water found underground in the
cracks and spaces in soil, sand and rock. It is stored
in and moves slowly through geologic formations of
soil, sand and rocks called aquifers.
What is Groundwater

• Groundwater makes up nearly 30% of all the world’s freshwater; only
0.2% is found in lakes, streams or rivers and 70% is bound up in snow
and ice on mountains and in the polar regions.
• Groundwater plays a number of very important roles in our environment
and in our economies. In the environment it supports rivers, lakes and
wetlands, especially through drier months when there is little direct input
from rainfall.
• The flow of groundwater into rivers as seepage through the river bed,
known as base flow, can be essential to the health of wildlife and plants
that live in the water.
• Groundwater also responds slowly to changes in rainfall, and so it stays
available during the summer and during droughts when rivers and
streams have dried up.
• Groundwater doesn’t require expensive reservoirs to store water in
before it is used.
Why groundwater is important?

Physical Context
• Bangladesh is located at the lowermost reaches of Ganges – Brahmaputra -
Meghna river system which drains 1.72 million km2 of land. Crucially,
Bangladesh itself comprises only 8% of the watershed.
• Generally, four major physiographic units exist at the surface of Bangladesh.
These are:
1. Tertiary sediments in the northern and eastern hills
2. Pleistocene Terraces in the Madhupur and Barind Tracts
3. Recent (Holocene) floodplains of the Ganges, the Brahmaputra and the
Meghna rivers and
4. The Delta covering the rest of the country.
• Most of the present land surface of the country covered by the Holocene flood
plains deposited by the GBM river systems.

Physiographic map of Bangladesh (Alam et al, 1991)
Physical Context

Aquifers is a body of permeable rock that can contain or
transmit groundwater. On a regional basis, three aquifers
have been identified and named by BWDBUNDP (1982).
These are:
• The Upper (Shallow) or the Composite
Aquifer
• The Pleistocene Aquifers
• The Holocene Aquifers
Pleistocene Dupi Tila aquifer of Dhaka city (Zahid et al, 2004)
Physical Context

Area irrigated with (a) surface water and (b) groundwater in Bangladesh
(BADC, 2013)
• The introduction of high yielding varieties in 1980s revolutionized rice
cultivation in Bangladesh.
• Increased water availability encouraged farmers to grow irrigated Boro rice
during the dry winter season. Currently, about 4.2 million ha of land is
irrigated by groundwater (both shallow and deep tubewells) whereas only
1.03 million ha is irrigated by surface water using low lift pumps (BADC
2013).
• This was probably due to decline in groundwater table depths in most
intensified areas which increases costs of groundwater irrigation. The area
irrigated by surface water declined from 76% in 1981 to 2013.
Patterns of Groundwater use

Hydrological Region of Bangladesh
Map of Bangladesh indicating the North West, North East, North Central, South Central, South East, and Eastern Hill
hydrological regions.

Hectares irrigated by groundwater and surface water by sub-district in the eight hydrological regions of Bangladesh
(Data: BADC 2012). NW: Northwest. SW: Southwest. SC: South Central. RE: River and Estuary. EH: Eastern Hills.
SE: South East. NE: North East. NC: North Central.
Zoning of ground and surface water

The achievement of sustainable groundwater development through the balance of recharge inputs to aquifer storage (the
groundwater resource) against discharge outputs for economic, environmental and human (social) benefits.
Sustainable Ground Water Development

1. Improving agricultural water use efficiencies
Prospects in Development of Ground Water Resources
• Due to lack of sufficient knowledge of irrigation scheduling and the
threat of non availability of irrigation water at the right time, farmers
rarely plan their irrigations in advance or attempt to coincide them with
critical periods of crop need.
• Where hose piping is not used, water is usually delivered through
unlined irrigation channels to fields that are poorly levelled.
• The additional pumping required as a consequence of inefficient
application also involves increased energy and financial costs for pump
owners.

2. Balancing aquifer recharge and discharge
The emergence of groundwater challenges poses two very major
challenges to the State.
• First, the performance of currently operational surface water supply
systems needs to be improved.
• Secondly, groundwater will have to be managed – for related
reasons of quantity and quality – much more aggressively than has been
the case in the past.
Aquifer management is considered as the most effective away of
establishing a balance between discharge and recharge components.
This practice is widely used in industrialized countries to recover
groundwater reserves.

3. Diversifying cropping patterns
Changes in the cultivated area of wheat and boro rice during 1970-2014.
• In Bangladesh’s main boro growing areas, more than 90% of irrigation water is
supplied through groundwater.
• Maize is another potential alternative crop to boro rice. Wheat and maize both
need very little water (300 to 500 mm) to meet their evapotranspiration demand,
especially when they are grown after the rice crop.
• A significant water requirement of these crops can be met through the
excessive moisture present in the root zone from the previous rice crop
especially if the strip or zero tillage method is used.

Cropping intensity, usually expressed as percentage, is the ratio of the
“total cropped area” in a year with “net cropped area” of that year.
Spatial variation and trend in cropping intensity

4. Revisiting groundwater governance policies
• Encouraging low water demanding high value crop in the NW region. Particularly
in Rajshahi, where GWT is declining rapidly.
• An estimated water budget should be prepared considering recharging,
extraction rates and change in the aquifer(s).
• Managed Aquifer Recharge should be undertaken as a national programmed
and strategy considering different regional contexts.
• Local planners should consider recharge areas when making land use planning
decisions that could reduce recharge or pose a risk to groundwater quality.
• Irrigation water price should be determined as a rule on volumetric basis in order
to meet equity, efficiency and economic principles
• Modern water management technology like alternate wetting and drying (AWD),
water saving technology, climate change adaptive technology would bear no
value without carrying out irrigation volumetrically
• National Sustainable Development Strategies by the government is a good effort
to achieve sustainability in all developmental activities
• Awareness campaign and advocacy on sustainable water management
concepts

• The increased availability of equipment led to the maturation of
Bangladesh’s mechanized agricultural economy.
• The leap in the population of STWs was linked their suitability to the
prevailing socioeconomic conditions of Bangladesh’s growing boro
rice.
• The temporal development of DTWs, STWs, and LLPs in
Bangladesh is shown in Figure 4. Currently, about 79% of the total
cultivated area is irrigated by groundwater, whereas the remaining is
irrigated by surface water (BADC 2013).
5.Groundwater consumption for irrigation

1. Declining water tables due to groundwater overdraft
Challenges in Development of Ground Water Resources
The substantial drawdown of
aquifers due to over-exploitation of
groundwater during the last decade
has been widely documented (Jahan
et al. 2010; Shahid 2011). Using data
from the Bangladesh Water
Development Board (BWDB), we
have determined that in areas with
water tables less than 8 m in depth,
decline has increased significantly
over time. Between 1998–2002, this
area was only ~4% of the
country’s total, but increased to
11% in 2008 and 14% in 2012. The
most significantly affected areas
lie in the north-west (e.g., Braind
Tract) and north-central (i.e.,
Madhupur Tract) regions.

2. Groundwater - Energy Nexus for Bangladesh
Kilograms of grain to buy one liter
of diesel (Data: BBS 2013)
Operational Characteristics of deep, shallow & low lift pumps for Boro rice season
• Groundwater irrigation requires large amounts of energy to
lift water from underlying aquifers.
• In 2012, about 49 billion kwh of electricity was generated in
Bangladesh, and about 2% of this total generation was used
to pump groundwater for irrigation.
• The subsidized cost of this electricity is about USD 50 million.
• Increasing power cuts and the generally poor electricity
network in many rural areas comprise other potential reasons
for farmers’ diesel pump preferences.

3. Arsenic contamination of groundwater
Fig: Arsenic concentration in
groundwater wells at different
depths (Source: BGS/DPHE,
2001)
Arsenic concentrations in STWs irrigation water (Duxbury et al.
2009)
• Groundwater by Arsenic (As) was
discovered in shallow aquifers of
Bangladesh (BGS-DPHE 2001)in
1990’s.

Total Wetland area in Northwest Bangladesh during the dry period
Changes in Wetland
areas in the Northwest
region of Bangladesh
during the dry period
4. Changes in Wetland areas during the dry period

• The availability of surface water is not consistent because of seasonal
variation. Ninety-five per cent of the surface water in the river system also
originates outside the country (Ahmad et al. 2001).
• Bangladesh experiences a tropical monsoon climate with significant variations
in rainfall and temperature. Average annual rainfall varies from 1,200 mm in
the extreme west to over 4,000mm in the northeast.
• Therefore there is a seasonal water shortage depending on the duration of the
monsoon.
5. Water shortage due to the duration of the monsoon
AVERAGE MONTHLY AND ANNUAL RAINFALL IN SELECTED REGIONS OF
BANGLADESH OVER 2002-2012(BMS 2013)

Deviation of monsoon (Jun-Sep) rainfall from normal over Rajshahi and Rangpur Division during
1980-2010*
Water resources consists of three main components - rainfall, stream flow
and ground water storage. These components, however, are closely
interrelated. For example, refilling of ground water reservoir each year
depends on monsoon season rainfall, stream flow and flood water.
Specially to the North-West region such as Rajshahi and Rangpur
division are mainly effected area for this reason.

• Ahmad MD, Turral H, Masih I, Giordano M, Masod Z (2007)
Water saving technologies: myths andrealities revealed in
Pakistan’s rice-wheat systems. International Water
Management Institute, Colombo, Sri Lanka (IWMI Research
Report 108), 44 pp.
• BADC. 2005. Survey Report on Irrigation Equipment and
Irrigated Area in Boro 2004 season. Bangladesh Agriculture
Development Corporation. p183.
• IUCN (2000) Balochistan conservation strategy. Government
of Balochistan and International Union for Conservation of
Nature.
• IWMI (2000) Water issues for 2025: a research perspective.
Research contribution to the World Water
• Vision. International Water Management Institute, Colombo.
REFERENCES

Prospects and challenges in development of ground water resources of bangladesh

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