Hydrological, Sedimentological, KII and

FGD Approach for Social and

Environmental Evaluation in Waterlogged

Areas of Tala Upazila, Satkhira

A Report Submitted In partial fulfillment of the Requirement for the Syllabus of

2nd

year, B.S. Honors in Disaster Science & Management

A Report Submitted by

Name: Ariful Islam

Exam Roll: 313

Registration no: 2012-212-208

Session: 2012-2013

Department of Disaster Science & Management

Faculty of Earth and Environmental Science

University of Dhaka

July, 2015

i

Acknowledgement

I first express my gratitude, devotion, love and respect to Almighty ALLAH for

making this happen. This field work along Tala Upazilla, Satkhira was really

very exciting and a very memorable one. I got chance to become more friendly

and free to my friends and my teachers by this field work in Sylhet.

I express my thanks and deepest sense of gratitude to our Honorable Chairman

Sir Prof. Dr. A.S.M. Maksud Kamal, Chairman of Disaster Science and

Management, University of Dhaka and Mamunur Rashid, National Project

Manager, PECM Project, United Nations Development Programme for their

spontaneous arrangement and caring guidance.

I also owe a debt of gratitude to our Team Leader Chairman Sir Prof. Dr.

A.S.M. Maksud Kamal, Chairman of Disaster Science and Management,

University of Dhaka. He deserves our thanks for his valuable lectures, good

planning for the trip and great affection.

My sincere appreciation and indebtness goes to our respected teacher B. M.

Rabby Hossain, Lecturer of Disaster Science and Management, University of

Dhaka for his technical suggestion and cordiality and his friendly attitude

during field work. His theoretical knowledge and previous research paper

helped me much to clarify my concept and complete this report.

My deepest gratitude and appreciation goes to our respected teachers Israt

Ferdous, Lecturer of Disaster Science and Management and S.M. Kamrul

Hassan, Lecturer of Disaster Science and Management for their technical

information, valuable lectures and quotes and much more their friendly

attitudes.

Special thanks to Jalalpur and Khesra Upazilla Parishad and UNO for various

support and in other purposes. My sincere appreciation also goes to the

UTTARAN, for our accommodation support. I am quite convinced with the

committee of food, transport and other first aid for their great and quick

voluntary service and all to my classmates and to my group members for their

sincere co-operation. My thanks also extend to the personnel of Disaster

Science and Management Department, the cooks and office assistants.

ii

Abstract

Three coastal districts of the South West Bangladesh (SWB) have been

experiencing problems of water-logging since the early 1980s. The term „water

logging‟ in this context means poor drainage of monsoon rain, with standing

water persisting for any period up to 6 months after the rains. This can cover

tens of thousands of hectares with a devastating effect on livelihoods, and

quality of life. Upazilas from Jessore (3), Satkhira (3) and Khulna (2) were

affected in the most recent episode during the last months of 2013.

Water logging in the south west coast is not just related to heavy rainfall and

extreme climatic events; it is also related to changes in the built-up areas

themselves. The south west coastal area is part of the tidal floodplain bounded

in the north by the Ganges floodplain and in the south by the Sundarban

mangrove tidal forest. The tidal floodplain is strongly influenced by tide,

salinity and rainfall. This plain is also crisscrossed by numerous tidal creeks or

channels and has high drainage density. Through natural process the rivers carry

both sweet water from upstream and tides from the sea. The major portion of

the floodplain is low-lying, barely one metre above mean sea level and below

high tide level. Homesteads, roads, vegetable gardens and orchards were

developed on areas artificially raised by digging ponds and ditches. Daily tides

used to inundate the lowlands twice a day.

Southwest coastal region in Bangladesh is faced with a challenge to manage

water resources and river basins. Development interventions since sixties to

increase food production, though resulted in high crop yield, have disrupted the

unique ecological systems of the region. Undermining the indigenous ecological

knowledge and community practice of water management has resulted in a

massive water logging crisis rapidly spreading to the whole region. The river

system of the region is passing through a critical time. Failure in urgent action

will unleash an environmental and humanitarian disaster of unprecedented

extent.

The way forward to work collectively, to bring the stakeholders together,

towards finding solution that is embedded in local traditions of water

management. Local communities have unique knowledge about the region.

Initiatives and projects without consulting them will only lead to failure and

aggravate the situation.

iii

Table of Contents

Page No

Abstract i

Acknowledgements ii

Table of Contents iii

Chapter 1: Introduction 1

Chapter 2: Literature Review 3

Chapter 3: Methodology 5

Chapter 4: Data Analysis, Result and Discussion 9

Chapter 5: Hazard Assessment 46

Chapter 6: Conclusion 47

References 48

Appendix 49

1

Chapter-1

Introduction

The study area, Satkhira, a coastal region of Bangladesh is situated within

Khulna division in the South-West part of the country, that has 7 upazilas and

one of which is Tala, the study area (specifically Kheshra and Jalalpur union).

The Tala upazila is located between 22°32‟ and 22°50‟ North latitudes and

89°05‟ and 89°20‟ East longitudes. The upazila has an area of 337.24 sq. km.

and population here is 299820 with the density being 889 per sq. km among

which 149389 are male and 150431 are female. The literacy rate is 50.9%. The

upazila has 12 unions and 229 villages within it. Khesra and Jalalpur are two of

the unions where study had been conducted. The population of these areas are

25,603 and 22,501 respectively and literacy rates are 44.66 and 44.67.

Figure 1: Map of study area (Tala upazila)

2

Bangladesh is known as a riverine country and like the other areas of the

country, Satkhira district is also blessed with a number of river (Kopotakkho)

and beels. But in the last few years the conditions of the rivers had been

worsened. Most of the rivers in the Southwestern region have been disturbed as,

continuous sediment deposition has risen up the river bed which is hampering

the natural flow of river, in turn it is also accelerating the deposition process as

low tide velocities. For this reason the rivers fail to play the role of natural

reservoir in the monsoon season and as a result overflows the surrounding areas.

As the drainage systems of these areas are not sufficiently good enough, the

areas remain waterlogged for even few months a year. Again, restricted river

flow due to embankments built for shrimp farming and fish cultivation,release

of water in monsoon from barrages in India (notably Farakkah Barrage and

Durgapur barrage) are all factors which have contributed to the current

situation. Besides water logging, people here also suffer from salinity and

scarcity of pure drinking water.

The socio-economic conditions of the people in these unions are not that up to

the mark. Domestic violence, premature marriage, unemployment problems are

quite prevalent here. People mainly earn livelihood by agriculture, fishing or as

day laborers. The communication system here is very poor. People are mainly

dependent on local transportation.

The purpose of the study was to evaluate the overall situation of the area by

assessing hydrological, sedimentological, vulnerability and socio-economic

condition.

3

Chapter-2

Literature Review

Depending on hazards, climate, hydrology, sedimentology, socio-economic,

agricultural conditions of sathkhira district many research works have been

done and there are many literature found on this topic that has a main or

common issue called water logging problem.

According toInvestigation of soil and water salinity, its effect on crop

production and adaptation strategy Salinity causes unfavorable environment

and hydrological situation that restrict the normal crop production throughout

the year. The factors which contribute significantly to the development of saline

soil are, tidal flooding during wet season (June to October), direct inundation by

saline water, and upward or lateral movement of saline ground water during dry

season (November to May). The severity of salinity problem in Bangladesh

increases with the desiccation of the soil. It affects crops depending on degree

of salinity at the critical stages of growth, which reduces yield and in severe

cases total yield is lost.

Impacts of Water logging on Biodiversity – Study on South-western Region of

Bangladesh describes significant effects on biodiversity in South-western

region. The study also finds that water logging affects peoples‟ wellbeing by

narrowing down the livelihood options of the people. Water logging squeezes

the scope for maintaining household economy by reducing the number of

livestock, fisheries, and restraining the growth of vegetation, fruit trees and

timber trees.

From the report The Development Disaster: Waterlogging in the Southwest

region of Bangladeshmillions of lives in this region become completely

stagnant. Now their life is on water. It is unbelievable that it is not natural

calamities like flooding or tsunami. It is truly man-made.

From the "Final Report Desakota Part II F1 Case Study Bangladesh" the

significant changes in hydro-morphological dynamics of Satkhira district and

the reasons behind the changes can be known. According to the report the

4

implementation of the Coastal Embankment Project (CEP) has brought

significant initial benefits to local population, by allowing them to cultivate

lands without being adversely affected by saline tidal effects. Crop production

has been demonstrated by enhanced sedimentation within the riverbeds, which

eventually choked up the rivers (Sarker, 2004; Islam et al., 2004). In absence of

coastal embankments, sedimentation could have otherwise happened naturally

in the entire floodplain, thereby rapid upliftment of riverbeds could have been

avoided.

Initial Assessment on Floods and Water Logging in South-West Bangladesh

Describes the situation the people, who were seriously affected by water

logging from late July, which are really indescribable. The affected villages

were under water with houses, livestock‟s and other assets including field &

homestead crop. At least 25% houses of the areas were inundated & flooded and

the people were taken shelter on the roads, schools grounds and other high areas

under the open sky as they still do not have any significant support for them and

they are marooned at the own hoping outsiders to support them to recover.

A report of "Mapping Exercise on Water logging in South-West of

Bangladesh" by Food and Agricultural Organization of the United Nations has

divided the effects of water-logging into two categories and they are:

(a) Immediate loss of life, property and access to essential services (such as

water and food) requiring humanitarian assistance, and

(b) Damage to infrastructure and other assets which affects livelihoods, health

and sanitation, shelters etc.

Snapshot on Waterlogging Situation in South-West Region of Bangladesh

highlights on severely affected upazila, No. of Affected Unions, Damage

Information on shelter, roads, embankments, agriculture, water, fisheris, and

Death of Livestocks

Also there are some reports on water logging situation in south west region by

Department of Disaster Management Ministry of Disaster Management and

Relief. At the homestead level, the direct impact is the loss of shelter, loss of

animals and sensitive plants, less access to safe food and water, loss of basic

services such as health or education; over the longer term, as water stands and

stagnates, risks are to health are described.

5

Chapter-3

Methodology

The study aims for a better understating of social and environmental evaluations

in water logged areas of tala upazila. Different types of data gathering

approaches were taken to collect data on water logged areas and the conditions

of the people of the affected areas (i.e. hydrological approach, sedimentological

approach, KII and FGD approach)

Hydrological Process

- Situation of tidal flow, tidal velocity, tidal current and other aspects in

the water logged areas: For better investigation tidal flow situation can

only be understood in high and low tides. The change in water level in river

is calculated by measuring tape, flow velocity is determined by using visible

floating objects. Travel time and distance is measured and flow velocity is

calculated and the process is done multiple times to get a real value.

- Water table and potentiometric surface of the area: It is the imaginary

plane where a given reservoir of fluid will "equalize out to" if allowed to

flow. A potentiometric surface is based on hydraulic principles.

- Hydraulic gradients and hydraulic heads: It is usually measured as a

liquid surface elevation, expressed in units of length, at the entrance (or

bottom) of a piezometer.

- Groundwater pH: pH is calculated from water collected from each aquifer

using pH meter. The pH scale ranges from 0 to 14. A pH of 7 indicates

neutral water; greater than 7, the water is basic; less than 7, it is acidic. A

one unit change in pH represents a 10-fold difference in hydrogen-ion

concentration.

- Groundwater salinity (expressed as milligrams per litre of chloride): It

refers to the total dissolved concentration of major inorganic ions (i.e.

Na,Ca, Mg, K, HCO3, SO4 and Cl) in irrigation, drainage and ground waters.

TDS, EC can be measured using an Electrical conductivity meterin the field.

The electrical conductivity of water is actually a measure of salinity.

Excessively high salinity can affect plants in the following ways:

Specific toxicity of a particular ion (such as Sodium)

6

Higher osmotic pressure around the roots prevents an efficient water

absorption by the plant.

Water class Electrical

conductivity

dS/m

Salt

concentration

mg/l

Type of water

Non-saline <0.7 <500 Drinking and

irrigation water

Slightly

saline

0.7 – 2 500-1500 Irrigation water

Moderately

saline

2 – 10 1500-7000 Primary drainage

water and

groundwater

Highly saline 10-25 7000-15 000 Secondary drainage

water and

groundwater

Very highly

saline

25 – 45 15 000-35 000 Very saline

groundwater

Brine >45 >45 000 Seawater

Table 1: Classification of Saline Water

- Environmental situation (water, sanitation): Focused Group

Discussion (FGD)

- Crop Pattern depending on water supply: Focused Group

Discussion (FGD)

- On-going projects conducted by government agencies, NGOs,

and community based organizations (CBOs) (FGD)

Sedimentation Process

- Sediment Types, Sedimentation Process, Influence of ocean current

- Quality of sediment, Quantity of Sediment

- How much sediment comes with high tide

- How much sediment might require to complete the TRM

- How many days it might take to deposit sediments at scale in the

pilot sites

7

Sampling

i. Suspended Sediment Concentration (SSC) in Water: Water samples

are to be collected in bottles and processed in order to quantify

Suspended Sediment Concentration.

ii. Deposited Sediments-inland (Auger-Method): Auger drilling is used

to collect previously deposited sediments. It is essentially manual

drilling equipment that can collect relatively undisturbed cores of

samples upto a certain (shallow) depth from the surface.

Overlaying cross-sectional data of the river bed

Amount/ Intensity of Sedimentation: The intensity of sedimentation

over a specified time frame can be determined using Sediment Traps.

PVC pipes/ Carpet/ Tiles are placed properly over the course of the study

area. Sediments deposited on top of them (Inside, in case of PVC pipes)

is measured and collected for further Analysis. Brick dust can also be

used as a marker horizon for this purpose.

Grain Size Analysis:

Samples collected can be analyzed in order to determine the grain size of

sediments using either of the following:

A) Sieve Method

B) Hydrometer

Sediment required to complete TRM:Auger method, cross section,

titles

Auger method and Sediment trap provide information about recent

sediment deposit rates in river bank and other parts of lands whereas

overlying cross sections of riverbeds provide information about sediments

deposited in the riverbed. The sediment traps (Tiles) to be deployed in the

field can provide measurements of sediment being deposited at the

current time. From this observation, the timeframe required to deposit

sediments at scale in the the pilot sites can also be determined. The

suspended sediment concentration measurements provide an idea of the

amount of sediments being carried by the rivers. Also taking SSC

measurements in both during high tide and low tide, can yield variation in

sediments in river water due to tidal variation. These measurements can

quantitatively provide an idea of the amount of sediments available for

deposition in the study area.

8

Environmental Assessment

- Rapid IEE of the TRM sites

- Probable Impact of TRM on Natural, Built and Cultural Ecosystem

(KII & FGD)

- Probable consequences on bio-diversity (flora and fauna) (KII &

FGD)

IEE Format:

Environmental clearance requirements

GOB Laws, regulations and guidelines on environmental

management

Specific Donor's environmental requirements (as applicable)

Environmental Issues and Concerns under the Project

Description of the available environment in the Project Area(s)

Currently available environmental quality of lands, air, and water

and their past trends (~20 years)

Environmental assessment of each activity envisaged (as in sub-

section 1.5 above): a present time, (b) into the future (~20 to 30

years)

Envisaged environmental safeguard actions (KII and FGD)

Potential of failures of envisaged safeguard actions (based on

current practices) (KII and FGD)

Final assessment of degradation of environmental quality due to

project implementation

Notification of unavoidable irreversible degradation of

environment

Modalities of stakeholders' response on environmental assessment

(prior disclosure is a pre-requisite)

Specific responses and recommendations of various stakeholder

groups

9

Chapter-4

Data Analysis, Results and

Discussion

4.1 The Sedimentation Process in the Study Area

Sedimentation Processes

Silt and clay with 15-20% fine and very fine sand is carried by the river system

as sediment load and these are deposited in the delta system and the rest is

flushed into the Bay of Bengal. Some of the flushed sediments may be reworked

by waves and ocean currents and can be deposited in the lower parts of the

delta. As the study area is located on the lower part of the delta plain having

lower elevations, the surface sediments of the region are generally silts to clayey

silts with generally <5% sand. The sediment accumulation of the overall region

is up to 1.1cm/yr. (based on some studies based on 137

Cs geochronology).

But the study area differs from such causes as the Kobadak River where

siltation process is ongoing and water logging due to drainage congestion. The

drainage congestion is considered to be a result of the following reasons:

Polderization

Encroachment

No freshwater from upstream during dry season (due to construction of

dams in upstream)

Siltation in streams influenced by tidal waters

Construction of unplanned bridges and roads that hinder natural flow

Natural Subsidence

10

Sediment Type and Grain Size :

Sediment grain size in analyzed from different sites of the study area using

sediment traps and recently deposited sediments were collected from there and

analyzed for grain size distribution using Hydrometer. The sediments deposited

in the area within the timeframe are 79-94% silt, 6-21% clay and 0.06-1.4% fine

sand. However, the study was carried out during the dry season whereas, in the

wet season, a higher energy condition prevails leading to coarser sediment

deposition. Sampling by auger method ( upto ~2.5m deep) was carried out to

determine the sediment types of the monsoon season. Silt dominated samples

throughout with presence of clay and minor sands were collected in auger.

Figure 2: Jalalpur-side channel (T-7)

Figure 3: Grain size analysis (T-7)

11

Figure 4: Jalalpur-TRM side channel (T-8)

Figure 5: Grain size analysis (T-8)

Figure 6: Khesra-main & side channel-Southern part of TRM (T-2)

12

Figure 7: Grain size analysis (T-2)

Figure 8: T-3 (Khesra near T2 beside paddy field-outside polder)

Figure 9: Grain size analysis (T-3)

13

Figure 10: T-4 (Khesra-inside polder-paddy field canal)

Figure 1: Grain size analysis (T-4)

Figure 2: T-5 (Khesra-near T2 lower bank)

14

Figure 3: Grain size analysis (T-5)

Figure 4: RIV-T5 (riverbed deposit near T5)

Figure 5: Grain size analysis (RIV-T5)

15

Figure 6: T-6 (Khesra northern end of TRM side)

Figure 7: Grain size analysis (T-6)

Figure 8: RIV-T6 (Khesra-riverbed deposit- T6)

16

Figure 9: Grain size analysis (RIV-T6)

Figure 20: Sediment Height (cm)

Figure 21: Sediment Amount (gm)

17

Figure 22: Sediment height (cm)

Figure 23: Sediment Weight (gm)

Quantity of Sediments

Riverbank Deposits:

The charts exhibit total sediments deposited in terms of deposited height and

weight in multiple days. The Cyan/Blue coloured trap sites mark Jalalpur site

whereas green/purple/blue marks the Kheshra Sites. The location of each trap

number is described in the table:

18

Trap

Name

Location

T-1 Jalalpur Kheyaghat

T-2 Kheshra -main&side channel-Southern part of TRM

T-3 Kheshra near T2 beside paddy field-outside polder

T-4 Kheshra -inside polder- paddyfield canal

T-5 Kheshra- near T2 lower bank

RIV-T5 Riverbed deposit near T5

T-6 Kheshra-northern end of TRM side

RIV-T6 Kheshra-riverbed deposit-t6

T7 Jalalpur - side channel (T-7)

T8 Jalalpur -TRM Side Channel(T-8)

Table 2: Trap name and location

To determine values of daily Sediment deposition in term of height and weight

the measured values have been recalculated. The factor that should be noted is

high tides and low tides occur twice a day. However, these sediments are loose

and will undergo compaction, consolidation and other processes, which will

ultimately compress the sediments. Jalalpur: Jalalpur have shown sediment

deposition of 0.1-0.7 cm/day. The average sediment deposition is considered to

be about 0.35 cm/day (See figure 44).Kheshra: Kheshra has sediment deposition

rate of 0.2-0.83 cm/day with average of 0.45cm/day. (See figure 45).

Riverbed Deposits

The following cross-sections of Kobadak River (BWDB) are observed below in

the figure. The Cross-Section number RMKBD11 and RMKBD11.1 are located

near the sites of Jalalpur and Kheshra respectively. As overlapping process

could not be carried out, the only one cross-sections each were available.

19

However, there was a cross-section RMKBD9.1, available in the upstream area,

which had temporal cross sections from which deposition in the riverbed were

measured. The depositional environment is similar in these locations, so the

values can provide an estimation in the target sites. The changes occurring from

2009-2013 in RMKBD 9.1 was 11 square meter which provides the average rate

of 2.75 square meter cross sectional area increase per year.

Figure 24: location of cross sections

Quality of Sediments

Grain size of the sediments carried out and deposited by the river, are

predominantly silt with clay and sometimes minor fine sand (<1%). The grain

isze is considered best for cultivation and nutrients and the flood plains are full

of nutrients so farming and grazing is done in dry seasons and often these places

remain waterlogged in wet seasons, thus subjected to significant amount of

20

organic materials and their relative decomposition. As the sediment is excellent

for cultivation, abundancy of paddy fields and vegetation is more significant in

these areas than the areas further away from river. Though sometimes paddy

fields near river bank follows salinity and crop damage can be seen.

Sedimentation Process and Influences

As the water flow has been absent over these years Kabadak River has been

subjected to massive siltation and as a result clogging up in the river is seen and

little or no flow from upstream is followed. The sediment caused drainage

congestion and decrease in river depth. The area is mainly drained by water

from these sources during the rising tide towards north and, during low tide, the

water flow back towards southern ocean. The flushed sediments are reworked

by strong tidal action and ocean current circulation and wave action generated

by waves.

Sediment Concentration in High Tides

The suspended sediment concentration (SSC) values are shown in following

graphs and the location, time of sampling and comments are shown in the

following table. The sampling shows higher values of SSC and greater velocity

but the water level is much lower and hence, the total amount of sediment

carried is also lower. Also, the riverbed being very shallow, the riverbed may

have been disturbed in some cases due to human activities nearby. (See figure

46)

Figure 25: SSC (gm/l)

21

The variations in SSC due to tidal influence was much more constant in

Jalalpur, compared to Kheshra which justifies the field observation of less tidal

influence in Jalalpur compared to the latter. (See figure 25)

SSC SITE

LOCATION

SSC

Value

(g/l)

LOCATION

DETAIL

COMMENT DATE

S-1 2.74 JALALPUR HIGH TO LOW TIDE 26-Nov

S-2 1.17 KHESHRA HIGH TIDE 26-Nov

S-3 5.58 KHESHRA LOW TIDE 27-Nov

S-4 1.22 KHESHRA LOW TIDE-INSIDE

POLDER-FLOWING

TOWARDS RIVER

27-Nov

S-5 7.02 KHESHRA LOW TIDE

(Turbulance nearby due

to human interference)

27-Nov

S-6 9.34 SHAHJADPU

R

-Natural TRM

LOW TIDE (Kheya

ghat, disturbed

sampling)

28-Nov

S-7 2.5 JALALPUR LOW TO HIGH TIDE 28-Nov

Table 3: SSC Value (g/l)

22

Figure 26: Comparison of Tidal variation in SSC

Jalalpur Site:

Figure 27: TRM++

Boundary in Jalalpur Union

23

Volume Estimation of Jalalpur TRM++ Site:

In order to identify how much sediment is required to fill up the TRM++ site in

Jalalpur union, we measured length, width and height of the filling site with

respect to the ground level. Findings are:

Average width of the TRM++ site: 260 m

Average Length of the TRM++ site: 450 m

Average height of the TRM++ site: 0.87 m

Volume of the proposed TRM++ site: (Length x height x height) =

(450x260x0.87) = 100620 m3

Average rate of deposition in Jalalpur TRM++site is 0.0035 m. So, the

deposition within the TRM boundary in Jalalpur site is 409.5m3/d. Total no of

day required to fill up the TRM site 245 if there is no regulation of the site and

without compaction.

Khesra Site:

Figure 28: TRM++

Boundary in Khesra Union

24

Volume Estimation of Khesra TRM++ Site:

In order to know how much sediment is required to fill up the TRM++ site in

khesra union, we measured length, width and height of the filling site with

respect to the polder level. Findings are:

Average width of the TRM++ site: 260 m

Average Length of the TRM++ site: 525 m

Average height of the TRM++ site: 1.7 m

Volume of the proposed TRM++ site: (Length x height x height) =

(525x260x1.7) =232050 m3

Average rate of deposition in Jalalpur TRM++

site is 0.0045 m. So, the

deposition within the TRM boundary in Jalalpur site is 614.25m3/d. Total no of

day required to fill up the TRM site 377 day if there is no regulation of the site

and without compaction.

5.2 Hydrological Process of Study Area

By hydrological process, the current hydrological condition and the probable

impact on hydrology and surrounding environment of the study area namely

jalalpur and khesra union of sathkhira district is studied.

Tidal Flow Situation and Current Velocity

To understand the complex tidal influences for better hydrological process as its

greater impact on geomorphology of the river it is very essential. Most

sediments come from ocean in high tides and deposits on the river back in low

tide. Velocity is measured to understand the sedimentation process.

25

Tidal velocity is measured using this formula, s = v x t

Here, S = Traveled distance of the floating object

V= Velocity of the current

T= Time required to travel the floating object

Tidal influence and current velocity of Jalalpur TRM++ site:

Tidal effect is less in Jalalpur and river depth is shallow (0.80 m water depth

during low tide +2.25 m water height with respect to low tide water depth=3.05

m). the river gets water only from tidal effect. Due to low current energy

sediment is suspended in these sites river bed is rising from the surrounding

low lying areas and thus creating water logged condition as the natural drainage

system becomes useless. Low tide velocity (around 1:15 pm) was 1 m/s. The

site of interest is 770 m away from the main river channel that is not straight,

having some angles thus interrupting the natural river or tidal flow. High tide

velocity was 0.78125 m/s (3:54 pm) which is lower than the velocity of the low

tide. The velocity must increase in summer season as the measurements were

taken in winter season.

Figure 10: Distance between the river and proposed TRM site in Jalalpur

26

Velocity value is also important as higher velocity or high energy condition can

carry more sediments and also retards the setting process of the sediments and

erode the river beds to maintain channel depth. From the velocity value we can

say that at what velocity and what grain size can be setteled using Hjulstroms

diagram. The graph is logarithmic.

Figure 30: Hjulström diagram for Jalalpur TRM site

The upper curve shows the critical erosion velocity in cm/s as a function of

particle size in mm, while the lower curve shows the deposition velocity as a

function of particle size. The plot shows relationships between erosion,

transportation, and deposition. For particle sizes where friction is the

dominating force preventing erosion, the curves follow each other closely and

the required velocity increases with particle size.

SILSiltT

Low Tide velocity Silt

27

Tidal influence and current velocity of Khesra TRM++ site:

TRM site of Khesra union is very near to the river Kobadak (Figure 22). Depth

of the river (9 meter) is deeper than that of Jalalpur area and has greater tidal

influence compared to the Jalalpur site. Tidal influence on the river bank site is

greater as the channel is wide. Width of the river at the study site is 35 meter.

Low tide measurement of river velocity (around 1:15 pm) was 0.87 m/s and

during the high tide it was 0.316 m/s. (3:20 pm). The studied site was 120 m

away from the main river channel.

Figure 31: TRM site of Khesra Union adjacent to the Kapotakkho River

Figure 32: Hjulström diagram for Khesra TRM site

SILT

SILT

28

The upper curve shows the critical erosion velocity in cm/s as a function of

particle size in mm, while the lower curve shows the deposition velocity as a

function of particle size. Note that the axes are logarithmic. From the velocity

value and sediments type which is mostly silt, the sediments will be transported

by current velocity and for deposition, the water need to be rested for hours as

well for this site as well and the system must be regulated.

Water table and Hydraulic gradient:

Knowledge of ground water process as it helps us to understand the

underground water movement. It can be explained if saline water encroachment

underground flow direction.

Water Table and Hydraulic Gradient of Jalalpur:

Water table Measurement – Jalalpur Union

Well

Name

Location Elevation

(m)

Water Table from ground

surface N E

TRM W

13

22.70842 89.26289 3 -1.8 m

TRM W

14

22.70339 89.26403 3 -2.08 m

TRM W

15

22.70067 89.26386 3 -1.7 m

TRM W

16

22.7058 89.26247 3 -1.5 m

TRM W

17

22.71404 89.25825 3 -0.6 m

TRM W

18

22.70994 89.25341 3 -1.6 m

TRM W

19

22.71351 89.25591 3 -1.1 m

TRM W

20

22.71095 89.25593 3 -1.1 m

TRM W

21

22.70693 89.25562 3 -1.3 m

Table 4: Water table data of Jalalpur Union

29

We have measured water table at nine different wells on both side of the

Kobadak river in Jalalpur union. Wells are well distributed on the north western

part (left side of the figure 24) but only 4 wells are measured for the water table

on the North eastern part of the river.

Figure 33: Well locations on both side of the Kobadak River in Jalalpur union

Water table in Jalalpur union from where shallow tube wells are extracting

water from underground is very shallow. Due to absence of piezometric well we

had to measure the water table using the shallow tube wells. Water encounters

at a depth of 0.6 m to 2.08 m at nine (9) different wells near the TRM site in

Jalalpur union (See table 6). The reason is to found water at very shallow depth

is the river bed is above the surrounding ground surface.

30

Figure 34: River is feeding the surrounding aquifers in Jalalpur union:

From figure 34 we can clearly see that the river is feeding the surround aquifer

which indicates as an influent river. The reason behind it may be the uprising of

the river bed due to lack of water flow in the river from upstream and energy

condition is also very low during tides.

Water Table and Hydraulic Gradient of Khesra

Water table measuring hand tube wells are well distributed in the Khesra Union

(Figure 35). Measurements were taken on both side of the river to understand

the influence of the river with groundwater table. Twelve tube wells water table

depth were measured and all of them were found at very shallow depth shown

in (See table 5).

River

31

Table 5: Water table data of khesra Union

Figure 35: Well locations on both side of the Kobadak River in Khesra union

Water table Measurement – Khesra Union

Well Name Location Elevation

(m)

Water Table from

ground surface N E

TRM W 1 22.6544 89.28146 3 -1.47 m

TRM W 2 22.65488 89.27811 3 -1.34 m

TRM W 3 22.6552 89.27829 3 -2.31 m

TRM W 4 22.65385 89.27951 3 -2.3 m

TRM W 5 22.66265 89.2858 3 -1.72 m

TRM W 6 22.6673 89.28401 3 -3 m

TRM W 7 22.66454 89.27985 3 -2 m

TRM W 8 22.66254 89.28369 3 -2 m

TRM W 9 22.66505 89.28371 3 -2.32 m

TRM W 10 22.65525 89.27344 3 -1.3 m

TRM W 11 22.65178 89.27348 3 -1.06 m

TRM W 12 22.65056 89.27696 3 -2.2 m

32

Groundwater levels was monitored using a measuring tape with a metal

"plopper" attached to the end of it. When jiggled up and down, we hear sound if

the plopper hits the water surface.

Figure 36: River is feeding the surrounding aquifers in Khesra union

From figure 36 we can clearly see that the river is feeding the surround aquifer

which indicates as an influent river. The reason behind it may be the uprising of

the river bed due to lack of water flow in the river from upstream and energy

condition is also very low during tides.

Groundwater salinity

For salinity, normal crop production in khesra and jalalpur is hampered due to

unfavorable environment and hydrological situation. Its responsible for low land

use as well as cropping intensity in the area. A practical index of salinity is

electrical conductivity (EC), expressed in dS/m or µS/cm. We also measures

33

TDS (Total dissolved solids), expressed in PPM (Parts per million), using

Electrical conductivity meter in the field.

Salinity condition in Jalalpur Union:

In total, salinity value is measured in 9 different wells on both side of the

Kobadak River. Well No. 13-16 on the north eastern side of the river and 17-21

on the north western part of the river which are very near to the proposed TRM

site.

Well

Name

Location Water Chemistry

N E EC TDS Temp

(c)

TRM W

13

22.70842 89.26289 4.63 dS/m 4630

µS/cm

>2000

PPM

26.7

TRM W

14

22.70339 89.26403 2.64 dS/m 2640

µS/cm

1970

PPM

TRM W

15

22.70067 89.26386 3.74 dS/m 3740

µS/cm

>2000

PPM

27.4

TRM W

16

22.7058 89.26247 1.22 dS/m 1220

µS/cm

820 PPM

TRM W

17

22.71404 89.25825 0.62 dS/m 620

µS/cm

450 PPM

TRM W

18

22.70994 89.25341 0.59 dS/m 590

µS/cm

428 PPM

TRM W

19

22.71351 89.25591 0.53 dS/m 530

µS/cm

371 PPM 27.2

TRM W

20

22.71095 89.25593 0.55 dS/m 550

µS/cm

382 PPM 27.2

TRM W

21

22.70693 89.25562 0.54 dS/m 540

µS/cm

409 PPM 26.2

Table 6: Water Chemistry Measurement – 1st site Jalalpur Union

34

Figure 37: TDS value distribution in different wells and ponds in Jalalpur Union

Figure 38: EC Value distribution at various wells and ponds in Jalalpur Union

35

Figure 11: EC value at different wells in Jalalpur Union

North eastern part of Kobadak River in shows the EC value relatively higher

than North western part of the river that shows relatively low EC value (0.5

Ds/M) which is very much drinkable and safe for health hazard.

Salinity condition in Khesra Union:

Well Name Location Chemistry

N E EC TDS Temp

(c)

TRM W 1 22.6544 89.28146 1.93 dS/m 1930

µS/cm

1560

PPM

24.9

TRM W 2 22.65488 89.27811 0.66 dS/m 660

µS/cm

474 PPM 24.1

TRM W 3 22.6552 89.27829 0.69 dS/m 690

µS/cm

488 PPM 25.4

TRM W 4 22.65385 89.27951 0.53 dS/m 530

µS/cm

383 PPM 24.7

TRM W 5 22.66265 89.2858 0.75 dS/m 730

µS/cm

540 PPM

TRM W 6 22.6673 89.28401 0.58 dS/m 580

µS/cm

418 PPM 25.1

TRM W 7 22.66454 89.27985 1.5 dS/m 1500 1090 25.2

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

TRM W 13

TRM W 14

TRM W 15

TRM W 16

TRM W 17

TRM W 18

TRM W 19

TRM W 20

TRM W 21

4.63

2.64

3.74

1.22

0.62 0.59 0.53 0.55 0.54

EC Value dS/m

EC Value dS/m

36

µS/cm PPM

TRM W 8 22.66254 89.28369 0.67 dS/m 670

µS/cm

485 PPM 25.4

TRM W 9 22.66505 89.28371 0.68 dS/m 680

µS/cm

496 PPM

TRM W 10 22.65525 89.27344 0.76 dS/m 760

µS/cm

550 PPM 26.7

TRM W 11 22.65178 89.27348 0.67 dS/m 670

µS/cm

470 PPM

TRM W 12 22.65056 89.27696 0.85 dS/m 850

µS/cm

618 PPM 26.6

Table 7: Water Chemistry Measurement – 2nd Site Khesra union

EC value in khesra union have measured in twelve different wells and we found

almost no anomaly except two wells namely w-1 and w-7 which falls in the

group of moderately saline water. Except these two wells all wells are safe for

drinking. (See figure 32)

Figure 40: TDS Value distribution at various wells in khesra Union

37

Figure 41: EC value distribution in Khesra

Figure 42: EC value at different wells in khesra Union

The bar diagram above shows the salinity distribution in different wells in

khesra. The range of the salinity in terms of EC value indicates that most of the

wells are safe for drinking except two wells namely w-1 and w-7.

0

0.5

1

1.5

2

TRM W 1

TRM W 2

TRM W 3

TRM W 4

TRM W 5

TRM W 6

TRM W 7

TRM W 8

TRM W 9

TRM W 10

TRM W 11

TRM W 12

EC Value dS/m

EC Value dS/m

38

Groundwater pH

Ground water, especially if the water is acidic, in many places contains

excessive amounts of iron. Iron causes reddish stains on plumbing fixtures and

clothing. Like hardness, excessive iron content can be reduced by treatment. A

test of the acidity of water is pH, which is a measure of the hydrogen-ion

concentration. The pH scale ranges from 0 to 14. A pH of 7 indicates neutral

water; greater than 7, the water is basic; less than 7, it is acidic. A one unit

change in pH represents a 10-fold difference in hydrogen-ion concentration. For

example, water with a pH of 6 has 10 times more hydrogen-ions than water with

a pH of 7. Water that is basic can form scale; acidic water can corrode.

According to U.S. Environmental Protection Agency criteria, water for

domestic use should have a pH between 5.5 and 9.

Jalalpur Union

Water table & Water Chemistry Measurement - Jalalpur(TRM)

Location Water Chemistry

Well

Name

N E PH W T

TRM W 1 22.70842 89.26289 6.8 1.8 m

TRM W 2 22.70339 89.26403 7 2.08 m

TRM W 3 22.70067 89.26386 7 1.7 m

TRM W 4 22.70058 89.26247 7 1.5 m

TRM W 5 22.71404 89.25825 7.2 0.6 m

TRM W 6 22.70994 89.25341 7.1 1.6 m

TRM W 7 22.71351 89.25591 7.2 1.1 m

TRM W 8 22.71095 89.25593 7.1 1.1 m

TRM W 9 22.70693 89.25562 7.1 1.3 m

Table 8: Water table & Water Chemistry Measurement - Jalalpur (TRM)

Figure 43: Bar diagram of PH value distribution in wells of Jalalpur

6.6

6.8

7

7.2

TRM W 1TRM W 2TRM W 3TRM W 4TRM W 5TRM W 6TRM W 7TRM W 8TRM W 9

PH

PH

39

Figure 44: PH value distribution in Jalalpur wells

Khesra Union

Water table & Water Chemistry Measurement - Khesra(TRM)

Location Water Chemistry

W T Well

Name

N E PH

TRM W 10 22.6544 89.28146 7.1 1.47 m

TRM W 11 22.65488 89.27811 6.5 1.34 m

TRM W 12 22.6552 89.27829 6.9 2.31 m

TRM W 4 22.65385 89.27951 6.9 2.3 m

TRM W 5 22.66265 89.2858 7.3 1.72 m

TRM W 6 22.6673 89.28401 7.2 3 m

TRM W 7 22.66454 89.27985 7.2 2 m

TRM W 8 22.66254 89.28369 7 2 m

TRM W 9 22.66505 89.28371 7.1 2.32 m

TRM W 10 22.65525 89.27344 6.9 1.3 m

TRM W 11 22.65178 89.27348 7.2 1.06 m

TRM W 12 22.65056 89.27696 7 2.2 m

Table 9: Water table & Water Chemistry Measurement – Khesra

40

Figure 45: Bar diagram of PH distribution in wells at Khesra Union

Figure 46: PH

distribution at wells in Khesra Union

6

6.2

6.4

6.6

6.8

7

7.2

7.4

TRM W 10

TRM W 11

TRM W 12

TRM W 4

TRM W 5

TRM W 6

TRM W 7

TRM W 8

TRM W 9

TRM W 10

TRM W 11

TRM W 12

PH

PH

41

Soil reaction values (pH) range from 6.8- 7.2 in Jalalpur union. Most of the well

waters falls into the normal range for drinking purpose. The pH values of the

paddy, land water and ponds are a bit higher than the tube well waters. In places

with higher pH values in the paddy fields, micronutrients‟ deficiencies are

expected.

Water Quality

Ph EC TDS Temp Sampling

area

1 7.9 3.03 mS 1* 23.8 c Paddy

2 7.8 2.71 mS 1* 25.5 c Drain

3 7.7 2.52 mS 1962 PPM 22.4 c Paddy

Table 10: Water chemistry of Jalalpur Pond and paddy field

5.3 Community Survey on Socio-Economic Condition (FGD & KII)

In general, vulnerability refers to the degree of loss. It is the degree to which an

individual, a household, a community or an area may be adversely affected by a

hazard (Zyl, 2010). To understand the social and environmental vulnerability of

the unions FGD and KII were conducted.

Data Analysis

Kheshra Union

Khesra is a union under Tala upazila of Satkhira district, which has an area of

47.84 km2. There are Jalalpur, Magura and Khalishkhali unions surrounding

Kheshra. Total population of the union is 25,603 and the number of households

is 5,523. 25.01% of the population of Khesra lives below the poverty line. Only

6.30 % households have electricity facility. In this union 53.3 % are farmers,

28.1 % are laborers and 7.7 % are businessman and 3.09 % are services holders.

Hygienic latrine is used by 37.7 % people. The union is protected by

embankment which is 5.3 km in length. There is no cyclone shelter in Khesra.

FGD‟s were done Shahzadpur, Gazipara and Shalikha village in Kheshra union.

Gazipara and Shahzadpur

This two neighboring villages share similar socio-economic and other

characteristics. They had to face devastating cyclone Aila in 2009 and a severe

flood in 2011. People in this two villages are mostly farmers. Mainly after Aila

and flood the villagers are constantly suffering from long term waterlogged

42

condition. The agricultural lands remain under 1-2 feet water during monsoon

season. As the river depth is decreasing day by day, the shallow river cannot

carry the excessive water during rainy season and as a result it overflows the

villages. Even after the monsoon the agricultural lands remain marshy for some

more periods and kills the season ripe for aman production. In past people of

this villages used to cultivate different types of crops like Sugarcane, Beatle

leaves, cauliflower, turmeric, date, radish, mustard, garlic etc. But after Aila,

saline water intrusion has decreased the fertility of the lands. Now only rice is

produced in this areas.

In the last five years the casualties due to disasters have been quite low. Proper

early warning system has improved the condition. It has lessened the death tolls.

But the casualties of domestic animals are very high. Because of waterlogging

there is shortage of food supply for livestock. Dry grazing zone for animals

become limited every year. During this crisis productivity of animals goes down

and some animals died of starvation in recent years.

The long term waterlogging has also changed the structure of houses in these

villages. Previously they used to live in earthen house which has short durability

and cannot hold on water. As a result people are now replacing the old structure

with CI sheet, brick or other water resistant materials at high cost. As people

can't bear the expenses most people are living in half constructed houses

without finishing inish the construction. There were houses with incomplete

window or door and people were living despite of less safety and security.

Waterlogging occurs not only due to shallow depth of river but also for some

canals which connects the low lying lands to the river that worked as drainage

system. At present these don‟t exist as they have been filled up by land owners.

For this the drainage system has been closed which is causing waterlogging.

There hasn‟t been any devastating flood since 2011. According to the union‟s

chairman, both aman and boro rice have been cultivated in the lands by the side

of the river which are a bit higher than villages.

Because of waterlogging people don't have any farmland. So every year they

remain workless for a long period of time. This has inspired migration of people

to other areas of the country or event to abroad (mainly India). In this time of

year they go to work at brick kilns for six months or go to Bay of Bengal for

fishing. Most common is migration to India which has intesified in the last few

years.

43

Shalikha

Shalikha is another village under Kheshra union where study had been

conducted. Shalikha river flows by the side of the village. It is a cluster village

where people were replaced for adjacent areas in 1980 by the government. The

people in this village are poorer than other villages. They own no other extra

land other than the land where they have built home. Most of them work as

agricultural day laborer.

There was no problem of waterelogging in this village when the river was in

motion. But as time passed by, the increased sedimentation has made the river

shallow and the water used to cause flood by overflowing. Deposition of

sediment has had clogged the sluice gate. But according to the villagers the river

was re-excavated in 2012, since then the problem of waterlogging has been

solved.

During the season of harvesting most of the people work as day laborer in other

peoples' field. As mentioned before, the economic condition of the residents are

very poor. So like men, women also work side by side. Bt because of gender

discrimination women get less wages than men though they work as hard as

men. For the same amount of work women are paid 100-150 taka while men are

paid 150-200 taka. The landlords of this area prefer shrimp cultivation over

agriculture as they get higher profit by cultivating shrimp. But the shrimp

cultivation doesn't require much human resource so there is less opportunity of

employment. In a bigha of agricultural land 5-6 people can work at the same

time as laborer but in the same amount of land in shrimp cultivation hardly one

wage earner can be employed properly. So people migrate to Bay of Bengal for

fishing or to Dhaka city and work as rickshaw puller.

Jalapur union

Jalalpur is a union located in Tala upazila of Satkhira district, with an area of

24.10 km2. The union is surrounded by Khalilnagar, Magura and Khesra unions.

There are 22,501 people in total and the number of households is 5,061. 25.01%

of the population of Jalalpur lives below the poverty line. Only 19.03% of the

households have access to electricity. Out of the total household, 48.5 % are

farmers, 24.8 % are laborers, 13.9 % are businessman and 2.91 % are services

holders. Hygienic latrine user is 46.8 %. There is 4.22 km flood protection

embankment. Also there is one cyclone shelter in Jalalpur.

Jalalpur :

Jalalpur village has an area of 785 km2

. 2148 people live here among which

1076 are male and 1072 are female. The literacy rate is 46.27%.The inhabitants

of Jalalpur village are vulnerable because their agricultural land is relatively at

44

low height than their housings so waterlogged situation influence the yearly

agricultural production. Waterlogged condition doesn't affect the people in

household and the livestock also remain safe.The increase in average inundation

depth is related with increased loss of agricultural production. Most of the

people in Jalalpur village is economically solvent as they have their own land

and many are associated with business.Every year during rainy season the Beel

area remains under 2-2.5 feet water for 2-3 months.

Majority of inhabitants belong to Hindu community, as a result they have their

own social norms so dowry related violence is prevalent in the society.

They have access to safe drinking water though their water contain very little

amount of saline.

During Aila and 2011's flood Jalalpur faced less damage than the Kheshra

union. But like Kheshra, the lands of Jalalpur has also become less fertile due to

saline intrusion.

Jethua:

The people of this village are resilient and they have social instrument to

reduce the adverse effects of water logging situation resulted from excessive

rainfall and poor drainage system. They cut canals by themselves. The increased

depth of canal allows more water to flow which reduces the chance of

waterlogging. They do not have enough property and most of them work as a

labor. During rainy season they switch to different occupation and migrate to

cities as most of the land remains inundated. Since there was a auto TRM in the

area, caused by polder breach, the depth of water in inundated areas are lower

than past years.

Result and Discussion:

From the FGD and KII important information were gathered about these areas.

Following outlines can be drawn from the above analysis.

I. The fertility of agricultural land have been decreased after the Aila of

2009 and flood of 2011. Saline intrusion is the main reason behind it.

II. Human casualties due to disasters are low in the region. But livestock

death during disaster due to no shelter and after disaster because of

scarcity of food is quite high.

III. Landlords are more interested in shrimp cultivation rather than

agriculture because of high profit. Besides waterlogging this fact is also

contributing to migration of people.

45

IV. Re-excavation or dredging may help to solve the waterlogging problem

according to the locals.

V. Returning the Kopotakkho river to its previous depths can result in better

opportunities for employment and communication.

The vulnerable elements in the locality can be presented as below

Elements at risk Possible vulnerabilities which allow this impact

Land Lower productivity

Reduced fertility

Livestock Starvation

Death

House Unstable

Reconstruction cost

Livelihood Job insecurity

Food insecurity

Income insecurity

Risky migration

Social cohesion Corruption, Mistrust

Conflict, Chaos

Table 11: Vulnerable elements in the locality

46

Chapter-5

Hazard Assessment

People from Different villages (Shahzadpur, Gazipara, Dumuria, Shalikha under

Khesra Union and Jetua & Jalalpur under Jalalpur union) in the study area were

interviewed to get an idea about different hazards of the area besides water

logging, though water logging is considered the primary hazard and the rest is

considered as the secondary hazards.

Village

Name

Location Primary

Hazard

Secondary Hazard Inundation Water

depth

Shahzadpur Khesra

Union

Flood, Water

logging

Scarcity of pure drinking

water due to salinity and

iron contamination and

crop failure

Moderately

inundated area (depth

of water 1-3 feet)

Gazipara Khesra

Union

Flood, Water

logging

Insufficient pure

drinking water due to

Arsenic contamination,

iron and salinity.

Highly inundated

area due to its lower

elevation than

Shahzadpur and other

villages (avg. depth

1.5-3 feet)

Dumuria Khesra

Union

Not exposed to

water logging

(in last 10

years)

Salinity Low inundated area

(avg. depth 1-2 feet)

Shalikha Khesra

Union

Water Logging

( Due to

sedimentation

near sluice

gates)

Social Conflicts due to

shrimp and fish

cultivation in beel areas

during rainy season

Low inundated area

(avg. depth 1-1.5

feet)

Jetua Jalalpur

Union

Flood in rainy

season

Waterlogging and crop

damage due to heavy

rainfall

Low inundated area

Jalalpur Jalalpur

Union

Surrounding

beel area

including the

cultivable

lands inundates

almost every

year

Waterlogging due to

sedimentation in

Kopothakho River

Low inundated area

47

To sum up, it can be said that the villages named Gazipara, Kanaidia,

Shahzadpur under Khesra Union can face more damage due to any hazard than

the other villages of Khesra Union. Beel areas of Jalalpur Union can also be

damaged.

Chapter-6

Conclusion

This report presents the results of a study conducted in 2014 into the factors leading to

water logging in the South West region of Bangladesh. It is intended to assist the

relevant institutions of the Government of Bangladesh address the underlying causes

of water logging. Ultimately, this will be for the benefit of local communities, and of

local institutions, and will improve their resilience to the threat of recurring and/or

long-lasting flooding. In 2008-09 Kobadak river almost lost drainage capacity due to

huge sedimentation and large area was inundated in the river basin. By this time, the

East Beel Khuksia tidal basin was brought under TRM operation in November 2006 to

maintain the drainage capacity of Teka-Hari River which improved drainage condition

of adjacent area. Again in 2011, sedimentation clogged Betna and Marirchap rivers

which caused severe water logging in the Kalaroa, Satkhira Sadar and Tala upazillas.

Water Master Plan prepared in 1964 introduced a compartmentalized polder or

enclosure system in the southwest tidal areas. 37 polders, 1566 kilometers of coastal

embankment and 282 sluice gates were constructed in the coastal area with funding

from USAID to prevent intrusion of saline water from sea and “recover” more land for

cultivation. On completion of the project, paddy production increased, but this was not

sustainable. But due to improper management and unplanned establishment of the

sluice gate the polder area gets affected by water logging because silt could not be

deposited in the tidal plain due to the embankments. Inside the polders, the wetlands

subsided due to subsidence and non-deposition of silt and gradually took the shape of

lakes. Thousand hectares of land have become waterlogged. The embankment

decreased the depth and the area of tidal prism. Salinity of the soil has increased due

to capillary action and vast agricultural lands have lost fertility. Many rivers are

drying up due to increasing silt on their beds during the dry months, only a very small

area of land can be cultivated since huge area remains under water.

48

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15. Ministry of Water Resources, Government of the People‟s Republic of

Bangladesh, Guidelines for Participatory Water Management, 2001.

16. M. Z. Hiader, and N. N. Moni, Consequences of Water logging: A Study on the

South-West Region of Bangladesh, Plan Plus, 5, 2009, 26-40.

17. Uttaran and Pani Committee, Water Resource Management in Southwest Region,

Peoples perspective and Participation, 2008.

18. Uttaran, Peoples„ Plan of Action: Management of Rivers of Southwest Coastal

Region in Bangladesh, 2011

19. WARPO, Guidelines for Environmental Assessment of Water Management (Flood

Control, Drainage and Irrigation) Projects, 2005.

49

Appendix

1. List of Tables

Table No. Table Name Page No.

1 Classification of Saline Water

6

2 Trap name and location 18

3 SSC Value (g/l) 21

4 Water table data of Jalalpur Union

28

5 Water table data of khesra Union 31

6 Water Chemistry Measurement – 1st site

Jalalpur Union

33

7 Water Chemistry Measurement – 2nd Site

Khesra union

35

8 Water table & Water Chemistry Measurement

- Jalalpur (TRM)

38

9 Water table & Water Chemistry Measurement

– Khesra

39

10 Water chemistry of Jalalpur Pond and paddy

field

41

11 The vulnerable elements in the locality 45

50

2. List Of Figures:

Figure No. Figure Name Page No.

1 Map of study area (Tala upazila) 1

2 Jalalpur-side channel (T-7) 10

3 Grain size analysis (T-7) 10

4 TRM side channel (T-8) 11

5 Grain size analysis (T-8) 11

6 Khesra-main & side channel-

Southern part of TRM (T-2)

11

7 Grain size analysis (T-2) 12

8 T-3 (Khesra near T2 beside paddy

field-outside polder)

12

9 Grain size analysis (T-3) 12

10 T-4 (Khesra-inside polder-paddy

field canal)

13

11 Grain size analysis (T-4) 13

12 T-5 (Khesra-near T2 lower bank) 13

13 Grain size analysis (T-5) 14

14 RIV-T5 (riverbed deposit near T5) 14

15 Grain size analysis (RIV-T5) 14

16 T-6 (Khesra northern end of TRM

side)

15

17 Grain size analysis (T-6) 15

18 RIV -T6 (Khesra-riverbed deposit-

T6)

15

19 Grain size analysis (RIV-T6) 16

20 Sediment Height (cm) 16

21 Sediment Amount (gm) 16

22 Sediment height (cm) 17

23 Sediment Weight (gm) 17

24 Location of cross sections 19

25 SSC (gm/l) 20

26 Comparison of Tidal variation in

SSC

22

27 TRM++

Boundary in Jalalpur Union 22

28 TRM++

Boundary in Khesra Union 23

29 Distance between the river and

proposed TRM site in Jalalpur

25

30 Hjulström diagram for Jalalpur 26

51

TRM site

31 TRM site of Khesra Union adjacent

to the Kapotakkho River

27

32 Hjulström diagram for Khesra TRM

site

27

33 Well locations on both side of the

Kobadak River in Jalalpur union

29

34 River is feeding the surrounding

aquifers in Jalalpur union

30

35 Well locations on both side of the

Kobadak River in Khesra union

31

36 River is feeding the surrounding

aquifers in Khesra union

32

37 TDS value distribution in different

wells and ponds in Jalalpur Union

34

38 EC Value distribution at various

wells and ponds in Jalalpur Union

34

39 EC value at different wells in

Jalalpur Union

35

40 Value distribution at various wells

in khesra Union

36

41 EC value distribution in Khesra 37

42 EC value at different wells in khesra

Union

37

43 Bar diagram of PH value

distribution in wells of Jalalpur

38

44 pH value distribution in Jalalpur

wells

39

45 Bar diagram of PH distribution in

wells at Khesra Union

40

46 PH

distribution at wells in Khesra

Union

40