A STUDY ON GROUNDWATER LEVEL IN THE SELECTED WELLS IN CHITTAGONG CITY

Presented by

Linkon Bhattacharjee MD.Misbah Uddin

Mahin ID: 0901024 ID: 0901079

  Supervised by

Dr. Aysha Akter Associate Professor

Department of Civil Engineering

Chittagong University of Engineering & Technology

BACKGROUND

Chittagong is the second largest city of Bangladesh, having around 157

km2 inhabited by 4.2 million people. Chittagong WASA is responsible for

water supply to one third of city dwellers and rest of people depends on

the shallow tube well and deep tube well.

Being the industrial capital of Bangladesh, paved area and withdrwal of

ground water in Chittagong is increasing day by day reducing infiltration

as well as natural recharge system. Thus ground water lowering has been

causing problem drawing our attention in to the project.

AIM AND OBJECTIVE

To determine the variation of ground water table in Chittagong city. The sub objectives are:

• To develop statistical relationship between yield and water depth using trend analysis; and

• To prepare a predictive map using kriging interpolation under GIS environment

METHODOLOGY Literature study

Investigation of location of tube wells in Chittagong City

Data collection from CWASA

Showing the variation of water level using Kriging method under GIS

Calculation of water table lowering

Result analysis and future recommendation

Available Information (CWASA,2014)

Halisohor-2

Halisohor-1

Dulalabad

Rongipara

Uttora

Fire S

ervice

Kornofully R/A

Agrabad

-1

Agrabad

-2

Agrabad

-3

CGS Colony

MOD-1

Bohutola

Jublee Road

Sadarg

hat

Love lan

e

Collegia

te

Firozsh

ah-1

firozsh

ah-3

Goalpara

policelin

e

Ice Fa

ctory

Bakolia

koibollo

dham

Hazicam

pFu

lcoli

Syedsh

ah0

5000

10000150002000025000

300003500040000

200920102011

Pum

ped

out w

ater

(gal

/hr)

Halisohor-2

Halisohor-1

Dulalabad

Rongipara

Uttora

Fire s

ervice

Karnofully

Agrabad

-1

Agrabad

-2

Agrabad

-3 CGS

MOD-1

Bahutola

Jublee Road

sadarg

hat

Love lan

e

Collegiat

e

Firozsh

ah-1

Firozsh

ah-3

Gowalpara

Policelin

e

Ice Fa

ctory

Jelaka

ragar

Koibollodham

Hazicam

p

Basundhora

Hajiprar

a

Syedsh

ahFu

lkoli

0102030405060708090

100

20112013

Wat

er Le

vel (

m)

KRIGING METHOD

STUDIED TUBEWELLSThe study area lies between 22°18'0 ″ to 22°24'0 ″ N latitude and 91° 46'0 ″

to 91° 51'0 ″ E longitude.

WATER TABLE VARIATION IN FIVE DIFFERENT WELLS (CWASA,2014)

In figure the groundwater level exhibits slow declining trend in five different locations which is within 14m range except in FIDC industrial area.

ANALYSIS PROCEDURE• For analyzing the average depth to water level and its variability in the

study area, the water level data of 2 years (2011 and 2013) recorded at CWASA was collected. The water level fluctuation was analyzed for year 2009 to 2013.

• Curve fitting using the regression equation y=mx+c was done for the required places to fill in for the missing data.

• The groundwater data and the discharge data assembled on yearly basis were analyzed for their long - term pattern, and were interpreted graphically to understand the dynamics of the groundwater level and discharge.

• The results were used to make the spatial variation maps of average depth to water level and water level fluctuation from the groundwater data.

• From analysis it is seen that discharge rate is decreasing year by year and hence water level is increasing.

RELATION BETWEEN DISCHARGE AND WATER TABLE

Thus discharge and water table are inversely proportional

GROUNDWATER LEVEL IN 2009• The minimum groundwater level was 4.88 m and the maximum

groundwater level was 84.76 m in 2009.• The average groundwater level in 2009 was found 43.83 m.

GROUNDWATER LEVEL IN 2010• The minimum groundwater level was 7.47 m and the maximum

groundwater level was 84.91 m in 2010.

• The average groundwater level in 2010 was found 47.06 m.

GROUNDWATER LEVEL IN 2011• The minimum groundwater level was 10.06 m and the maximum

groundwater level was 85.06 m in 2011.• The average groundwater level in 2011 was found 50.29 m.

GROUNDWATER LEVEL IN 2012• The minimum groundwater level was 12.65 m and the maximum

groundwater level was 86.72 m in 2012.• The average groundwater level in 2012 was found 53.54 m.

GROUNDWATER LEVEL IN 2013• The minimum groundwater level was 15.24 m and the maximum

groundwater level was 92.26 m in 2013.• The average groundwater level in 2013 was found 56.74 m.

VARIATION IN WATER TABLE FROM 2009 TO 2013

GROUND WATER LOWERING RATE It has seen that water level lowering rate is 0.122 to 7.922 m/year in

the studied wells.

Halisohor-2

Halisohor-1

Dulalabad

Rongipara

Uttora

Fire S

ervice

Agrabad

-1

Agrabad

-2

Agrabad

-3

CGS Colony

MOD-1

Bohutola

Jublee Road

Sadarg

hat

Love lan

e

Collegiat

e

Firozsh

ah-1

firozsh

ah-3

Goalpara

policelin

e

Ice Fa

ctory

koibollo

dham

Hazicam

pFu

lcoli

Syedshah

0

2

4

6

8

10Water table decline rate (m/year)

Decli

ne ra

te (m

/yea

r)

Halisohor-2

Halisohor-1

Dulalabad

Rongipara

Uttora

Fire s

ervice

Karnofully

Agrabad

-1

Agrabad

-2

Agrabad

-3 CGS

MOD-1

Bahutola

Jublee Road

sadarg

hat

Love lan

e

Collegiat

e

Firozsh

ah-1

Firozsh

ah-3

Gowalpara

Policelin

e

Ice Fa

ctory

Jelaka

ragar

Koibollodham

Hazicam

p

Basundhora

Hajiprar

a

Syedsh

ahFu

lkoli

0102030405060708090

100 Water level of five years

20092010201120122013W

ater

Leve

l (m

)

RECOMMENDATIONS

• The groundwater table monitoring should be done regularly for

assessment of annual safe yield.

• Large scale groundwater withdrawal by tube wells should be limited

during dry period up to safe yield limits.

• An alternative pump can be installed for drinking water supply in

the areas where water is highly abstracted.

Thank You