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Effect of Climate Change on Water Resources in Barind Tract of Rajshahi District

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The Barind tract under Rajshahi district is a highland drought prone area where needs of water meet up mainly from groundwater and small water bodies. Huge water is extracting from groundwater mainly for irrigation in this region. Moreover, climate change becomes a additional threat for this region like other part of globe. The study focuses on the effect of climate change on the water resources in this region for the better understanding the present situation to take necessary action for proper management of water resources. The surface water area calculation is mainly a software based analysis process from satellite image using GIS and Erdas Imagine. Air temperature and rainfall data as well as static water level of nine Upailas of Rajshahi district were analyzed to understand the relationships. The study shows that the annual average maximum and minimum temperature follow increasing trends while rainfall follows decreasing trend. It means that availability of water is reducing with increase of air temperature. Similarly surface water areas are decreasing significantly of 50.6 sq.km from 1990 to 2010 at an average rate of 2.53 sq.km per year. During the study period, on an average more than 2.5 m groundwater table was depleted which is extremely alarming for future water resources management planning. Therefore, immediate actions need to be taken overcome the situation.
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Proceedings of the 5th International Conference on Engineering Research, Innovation and Education
ICERIE 2019, 25-27 January, Sylhet, Bangladesh
378
Effect of Climate Change on Water Resources in Barind Tract
of Rajshahi District
Bari, M.N.a*, Roknuzzaman, M.b and Islam, M.T.a
aDepartment of Civil Engineering, Rajshahi University of Engineering &
Technology, Bangladesh. E-mail: niamulbari@yahoo.com
bDepartment of Civil Engineering, Hajee Mohammad Danesh Science & Technology
University, Bangladesh. E-mail: mrz.civil@hstu.ac.bd
*Corresponding author [Md. Niamul Bari]
Keywords:
Climate change;
surface water body;
groundwater table
depletion;
rainfall;
atmospheric
temperature.
Abstract: The Barind tract under Rajshahi district is a highland drought
prone area where needs of water meet up mainly from groundwater and
small water bodies. Huge water is extracting from groundwater mainly for
irrigation in this region. Moreover, climate change becomes a additional
threat for this region like other part of globe. The study focuses on the effect
of climate change on the water resources in this region for the better
understanding the present situation to take necessary action for proper
management of water resources. The surface water area calculation is mainly
a software based analysis process from satellite image using GIS and Erdas
Imagine. Air temperature and rainfall data as well as static water level of
nine Upailas of Rajshahi district were analyzed to understand the
relationships. The study shows that the annual average maximum and
minimum temperature follow increasing trends while rainfall follows
decreasing trend. It means that availability of water is reducing with increase
of air temperature. Similarly surface water areas are decreasing significantly
of 50.6 sq.km from 1990 to 2010 at an average rate of 2.53 sq.km per year.
During the study period, on an average more than 2.5 m groundwater table
was depleted which is extremely alarming for future water resources
management planning. Therefore, immediate actions need to be taken
overcome the situation.
1. Introduction
Water resources comprises of surface water and groundwater resources that is the major
resource for availability of water. Water is a part of life in all respects which is threatened by
climate for its sustainability considering quantity and quality. Temperature is one of the
important factors that influence the availability of water. Water loss increases with increase of
temperature through evaporation and transpiration to return to the atmosphere (Kumar, 2012).
Not only losses of water but demand of water also increases at higher temperature. As a
consequence, consumption of water increases and water resources reduce.
The Intergovernmental Panel on Climate Change (IPCC) estimates that the global mean surface
temperature has increased 0.6 ± 0.2 o C since 1861, and predicts an increase of 2 to 4 oC over the
next 100 years. Global sea levels have risen between 10 and 25 cm since the late 19 th century.
As a direct consequence of warmer temperatures, the hydrologic cycle will undergo significant
379
impact with accompanying changes in the rates of precipitation and evaporation (Kumar, 2012).
Climate change can have profound effects on the hydrologic cycle through precipitation,
evapotranspiration, and soil moisture with increasing temperatures.
The effect of climate change on unconfined aquifers is more compare to confined aquifers due to
they are generally shallow and often hydraulic connection with surface water where river-
groundwater interactions control the impact of recharge on both systems (Caballero and
Ladouche, 2015; Scibek and Allen, 2006; Allen et al., 2004). Although groundwater resources are
often critical for agricultural and drinking water uses, the impact of climate change on
groundwater is less frequently analyzed than for surface water (Caballero and Ladouche, 2015).
The relationship between the changing climate variables and groundwater is more complicated
and poorly understood. The greater variability in rainfall could mean more frequent and prolonged
periods of high or low groundwater levels. Groundwater resources are related to climate change
through the direct interaction with surface water resources, such as lakes and rivers, and indirectly
through the recharge process. The direct effect of climate change on groundwater resources
depends upon the change in the volume and distribution of groundwater recharge.
Moreover, the major long-term climate variables such as air temperature and precipitation
directly affect the surface water resources. Climate change is expected to exacerbate current
stresses on water resources resulting from population growth, economic factors and land use
changes, including urbanization. On a regional scale, mountain snow packs, glaciers and small
ice caps play a crucial role in freshwater availability. Widespread mass losses from glaciers and
reduction in snow cover, reported in recent times, are projected to accelerate throughout the 21st
century, reducing water availability, hydropower potential, and changing seasonality of flows in
regions supplied by melt water from major mountain ranges, where more than one-sixth of the
world population currently lives. Runoff is projected with high confidence to increase by 10 to
40% by mid-century at higher latitudes and in some wet tropical areas, including populous areas
in East and South-East Asia due to increase in rainfall and lower rates of evapotranspiration.
Also, it is projected to decrease by 10 to 30% over some dry regions at midlatitudes and dry
tropics, due to decrease in rainfall and higher rates of evapotranspiration. There is also high
confidence in the projection that many semi-arid areas will suffer a reduction in water resources
due to climate change. Drought-affected areas are projected to increase in extent, with the
potential for adverse impacts on multiple sectors, including agriculture, water supply, energy
production and health.
Regionally, large increase in irrigation water demand is projected as a result of climate change.
In Asia, it is estimated that the mean continental surface temperatures increased by
approximately 0.7°C over the 20th century and a further warming of 0.2-0.5°C per decade is
predicted for 2070-2100. This rise in surface air temperatures will affect the quantity and
quality of regional water resources. Since hydrologic conditions vary from region to region, the
influence of climatic change on local hydrological processes will likely differ between
localities, even under the same climatic scenarios. Studies in recent years have shown important
regional water resources vulnerabilities to changes in both temperature and precipitation
patterns (Raneesh, 2014).
The part of greater Rajshahi, Dinajpur, Rangpur and Bogra District of Bangladesh and the
Indian territorial Maldah district of west Bengal is geographically identified as Barind Tract.
The Rajshahi Barind Tract is in the North-West region of Bangladesh. In Barind Area surface
water sources are very limited. Rainfall is very less compared to the other parts of the country.
The annual rainfall varies from minimum 1250 mm to a maximum 2000 mm and the average
annual rainfall is 1418 mm (IWM, 2012) whereas the country average is 2500 mm. Almost 80%
380
of the rainfall occurs during June to October. High temperature prevails in this area during dry
period, which goes above 35oC. Due to high elevation of Barind, it is located in flood free zone.
So, only source of groundwater recharging in this area is rainfall, but lowest amount of rainfall
occur in this northwestern part of Bangladesh and it is also a very severely drought prone area
(Rahaman and Mahbub, 2012). The main focus of this research is to understand the effects of
climate change on surface water and groundwater in barind tract of Rajshahi district considering
the parameters, temperature and precipitation (rainfall) of Rajshahi District for ensuring its
appropriate management and utilization.
2. Methodology
This study is mainly based on the estimation of area of surface water bodies by using GIS
(Geographic information system) and groundwater level fluctuation at Barind tract in Rajshahi
District to determine the effect of climate change. Temperature and rainfall data of 1990 to 2010
is collected from Bangladesh Meteorological Department (BMD) and static Ground water level
data is collected from Barind Multipurpose Development Authority (BMDA). GIS and ERDAS
IMAGINE (version 2015) software is used for classification and area calculation with the
Satellite image collected from an open source. Landsat images of different years were
downloaded from website www.earthexplorer.usgs.gov. The image was added to ArcGIS and
Composite Band image was created. The shape file of Rajshahi area was exported to ERDAS
IMAGINE for image classification. The classified area using Zonal Geometry as table was
calculated by using ArcGIS.
3. Results and Discussions
The experiences in climate variability and extreme events of the observed climate change of
Rajshahi District were analyzed and discussed in this study. It contains the detail results of the
changing trend of water surface area, temperature variability and rainfall scenario of the study
area. The observations are discussed in the following sections.
3.1 Area variation of water bodies
A geographic information system or geographical information system (GIS) is a system
designed to capture, store, manipulate, analyze, manage, and present all types of spatial or
geographical data. GIS is a broad term that can refer to a number of different technologies,
processes, and methods. It is attached to many operations and has many applications related to
engineering, planning, management, transport/logistics, insurance, telecommunications, and
business. For that reason, GIS and location intelligence applications can be the foundation for
many location-enabled services that rely on analysis and visualization.
ERDAS IMAGINE is aimed primarily at geospatial raster data processing and allows the user to
prepare, display and enhance digital images for mapping use in geographic information system
(GIS) or in computer-aided design (CAD) software. It is a toolbox allowing the user to perform
numerous operations on an image and generate an answer to specific geographical questions. By
manipulating imagery data values and positions, it is possible to see features that would not
normally be visible and to locate geo-positions of features that would otherwise be graphical.
The level of brightness or reflectance of light from the surfaces in the image can be helpful with
vegetation analysis, prospecting for minerals etc.
Areas of water bodies in study area were analyzed for year of 1990, 1996, 2000, 2004 and 2010
with help of ERDAS IMAGINE and GIS system. The images are presented in Fig. 1 where blue
381
coloured area in image indicates the water bodies and the estimated area of water bodies from
image analysis is shown in Table 1.
Fig. 1: Image showing the water bodies of Rajshahi District
Table 1: Variation of areas of water bodies of Rajshahi district
382
Year Water area (sq. km) Loss of area (sq. km) Rate of area loss (sq. km)
1990 282.5 - -
1996 267.9 14.6 2.43
2000 256.5 11.4 2.85
2004 251.6 4.9 1.23
2010 231.9 19.7 3.28
Total loss 50.6 2.53
It is observed from Table 1 that the areas of water bodies are decreasing gradually. About 50.6
sq.km of area was reduced from 1990 to 2010 at an average of 2.53 sq.km in every year.
Furthermore, the rate of water body loss is also gradual increasing and about 17.9% of water
bodies are lost from 1990 to 2010. From this analysis it could be assessed that the loss of water
bodies will be of 75.9 sq. km. by 2020 and 101.2 sq.km by 2030 that 26.9% and 35.8%,
respectively. It means that water body will remain only two-third if the rate of water body loss
follows the same trend. However, rapid urbanization accelerates the loss of water bodies.
3.2 Effect of temperature variation on rainfall
It is well established that the hydrologic cycle is influencing by atmospheric temperature. Due
to the change in air temperature rainfall intensity, distribution and frequency are varying. For
the local management of water resources appropriately the effect of temperature variation on
rainfall for particular region is essential to determine. Moreover, water storage in water bodies,
groundwater recharge and evapotranspiration are directly dependent on temperature and
rainfall. The variation of air temperature and rainfall are presented in Fig. 2 to understand the
relationship between these two elements of climate.
Fig. 2: Relationship between air temperature and rainfall
Fig. 2 depicted that the trend is increasing for both annual maximum and minimum temperature
variation from 1990 to 2010. On the other hand, the trend of rainfall is decreasing for same
period. The figure clearly explains that the rainfall is decreasing with increase of temperature in
Rajshahi district. From this study it could be mentioned that Rajshahi district will face extreme
conditions with higher temperature and lower rainfall in near future.
10
15
20
25
30
35
40
500
1000
1500
2000
2500
1985 1990 1995 2000 2005 2010 2015
Year
Rainfall Min. Temp. Max. Temp.
383
3.3 Effect of temperature variation on water body
Area of water bodies depends on the availability of storage water and it mainly comes from
rainfall and evapotranspiration. Evapotranspiration increases with increase of temperature. Area
of water bodies increases mainly from storage of rainwater. The relationship between
temperature and available area of water bodies is presented in Fig. 3. From figure it is obvious
that areas of water bodies are reducing with increase of temperature. It could be due the use of
more water to fulfill the increased demand, more evaporation and transpiration, and less rainfall.
Fig. 3: Relationship between air temperature and area of water body
3.4 Effect on groundwater table
Barind Multipurpose Development Authority (BMDA) keeps record of groundwater
fluctuations for Barind tract. The available groundwater table data for 2005 to 2015 are plotted
in Fig. 4 to understand the groundwater condition.
It is obvious that the groundwater is replenishing in few years but the trend of groundwater
fluctuation is decreasing except Bhaga and Charghat Upazila under Rajshahi district. It means
that the groundwater table is depleting gradually with year in seven Upazilas out of nine in the
study area. The fluctuation of this groundwater table is mainly due to the abstraction of
groundwater and natural recharge from rainfall. BMDA uses groundwater from deep aquifer by
abstracting for irrigation in their command area and natural recharge is very limited due the clay
layer at top 10 to 15m.
0
5
10
15
20
25
30
35
40
0
50
100
150
200
250
300
1985 1990 1995 2000 2005 2010 2015
Year
Water body Min.Temp. Max.Temp.
384
Fig. 4: Variation of groundwater table in Barind tract
4. Conclusion
Most of the part of Rajshahi district is considered as highland Barind tract which drought prone
area of Bangladesh. The study shows that the maximum and minimum air temperature
following the increasing trend and annual rainfall trend is decreasing. As a result, availability of
water is reducing due to shortage of water storage in water bodies and groundwater table due to
less recharge. As a consequence, areas of surface water bodies are reducing and groundwater
table is also depleting gradually. If same climatic trend is continuing, the Barind tract will
experience extreme situation due to the scarcity of water and high atmospheric temperature in
near future. Therefore, immediate necessary actions need to be taken.
5. References
Kumar, C.P. (2012), Climate Change and Its Impact on Groundwater Resources,
RESEARCH INVENTY: International Journal of Engineering and Science ISSN: 2278-
4721, Vol. 1, Issue 5 (October 2012), PP 43-60.
Caballero, Y. and Ladouche, B. (2015), Impact of climate change on groundwater in a
confined Mediterranean aquifer’, Hydrol. Earth Syst. Sci. Discuss., 12, 1010910156.
doi:10.5194/hessd-12-10109-2015.
Allen, D.M., Mackie, D.C. and Wei, M. (2004), Groundwater and climate change: a
sensitivity analysis for the Grand Forks aquifer, southern British Columbia, Canada,
Hydrogeol. J., 13, 270290.
Scibek, J. and Allen, D.M. (2006), Modeled impacts of predicted climate change on
recharge and groundwater levels, Water Resour. Res., 42 doi:10.1029/2005WR004742,
2006.
Raneesh K.Y. (2014), Impact of Climate Change on Water Resources’, J Earth Sci
Clim Change 5: 185. doi:10.4172/2157-7617.1000185
0
5
10
15
20
25
30
2004 2006 2008 2010 2012 2014 2016
Year
Godagari
Tanore
Paba
Mohonpur
Bagmara
Durgapur
Puthia
Bagha
Charghat
Avg.
385
Rahman, M. and Mahbub A.Q.M, (2012), Groundwater Depletion with Expansion of
Irrigation in Barind Tract: A Case Study of Tanore Upazila, Journal of Water Resource
and Protection, 4, 567-575.
https://file.scirp.org/pdf/JWARP20120800001_35403762.pdf
IWM, (2012), Groundwater Resources Study and Decision Support System
Development of Rajshahi, Naogaon, Chapai Nawabganj, Pabna and Natore Districts
and Also Remaining District of Rajshahi Division through Mathematical Model Study
for Barind Integrated Area Development Project, Phase-III, Final Report, Vol. 1.
... Its average temperature ranges from 25 to 35 • C in the hottest season and 9 to 15 • C in the coolest season. In summer, some of the hottest days experience maximum temperatures of about 45 • C or more, while in winter it falls to around 5 • C [21]. So, this region experiences extremes that are in clear contrast to the climatic condition of the rest of the country. ...
... summer, some of the hottest days experience maximum temperatures of about 45 °C or more, while in winter it falls to around 5 °C [21]. So, this region experiences extremes that are in clear contrast to the climatic condition of the rest of the country. ...
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Groundwater Resources Study and Decision Support System Development of Rajshahi, Naogaon, Chapai Nawabganj, Pabna and Natore Districts and Also Remaining District of Rajshahi Division through Mathematical Model Study for Barind Integrated Area Development Project
https://file.scirp.org/pdf/JWARP20120800001_35403762.pdf  IWM, (2012), 'Groundwater Resources Study and Decision Support System Development of Rajshahi, Naogaon, Chapai Nawabganj, Pabna and Natore Districts and Also Remaining District of Rajshahi Division through Mathematical Model Study for Barind Integrated Area Development Project', Phase-III, Final Report, Vol. 1.