Geographic Information System and Remote Sensing Data Analysis at ArcGIS

1. Meghna River Bank Erosion Analysis
At Haimchar Upazila, Chandpur using
GIS and RS Techniques
Presented by:
Masuda Sultana
B-150602060
12th Batch
GEO-4207: Dissertation.
Supervised by:
Dr. Muhammad Al-amin Hoque
Associate Professor
Dept. of Geography & Environment,
Jagannath University.
Department of Geography & Environment
JAGANNATH UNIVERSITY

2. BACKGROUND
 River bank erosion is the wearing away of the banks of a stream or river. More
than 750 million South Asian people depend on the transboundary Ganges-
Brahmaputra-Meghna river basin for their livelihood. Along with Bangladesh
one million Souh Asian people affected and up to 200,000 displaced every
year.
 River bank erosion is one of the frequent but the most unpredictable disasters
that occur every year in Bangladesh (Hasan, 2016). The Lower Meghna moves
down to the Bay of Bengal through the Haimchar Upazila at Chandpur and
causes many impact like migration every year their livelihood.
 Geospatial analysis can help to identify the impact and to determine the
solution for this severe problem.
 Khan et al. 2014; Akter et al. 2017; Hassan et al. 2017 conducted their
research on Jamuna river band erision and Biswajit et al. 2013 conducted
research on Meghna River bank erosion. Taleb et al. 2009 conducted research
on socio-economic impact on displaced people at Haimchar Upazila, Chandpur
District, Bangladesh. I will focus on the erosional change on the study area.

3. STATEMENT OF THE PROBLEM
 Bangladesh is a riverine country. People are directly or indirectly dependent
on the rivers of this country. River plays a vital role in the livelihood pattern
of the people who are mostly influenced by the rivers.
 River bank erosion is taking place in about 94 out of 489 upazilas of the
country. Researchers have identified 56 upazilas with incidence of erosion. It
is estimated that about 5% of the total floodplain of Bangladesh is directly
affected by river bank erosion.
 The changing trend of Riverbank is creating many socio-economic problems in
the proximate areas. Millions of people have been dislocated from their
original living places because of acute riverbank erosion in Bangladesh. Every
year, millions of people are affected by erosion that destroys standing crops,
farmland and homestead land during heavy rainfall in the monsoon period
which causes monsoon or riverine flood.

4. LITERATURE REVIEW
 From the above review of literature, I can say many of the research had been
conducted on the Jamuna River bank and those work had been done in the
Meghna they were not in recent time. The above research work had been
conducted before 2017. And the reseach had been conducted for socio-
economic purpose to identify thw impact of the peopled near erosion prone
area for continuous migration and displacement. Recently I did not found any
research work on Meghna River bank erosion near at Haimchar Upazila,
Chandpur district. So, I wanted to show Meghna River bank erosion-accretion
and the change of river bank from 1988 to recent year 2021. I will also show
some mitigation ways for preventing river bank erosion in the study area.

5. AIM & OBJECTIVES
 The aim of this research is to identify and assess Meghna riverbank erosion at
Haimchar upazila, Chandpur. The following objectives are kept in mind in
order to fulfill the aims:
i. To discuss the factors causes river bank erosion.
ii. To create Meghna river bank erosion map and assess erosion and accretion at
Haimchar upazila.
iii. To recommend the mitigation measures to prevent the bank shifting or
erosion to prevent the displacement of the local people.

6. STUDY AREA
 Haimchar is an Upazila of Chandpur District in the Division of Chittagong,
Bangladesh. The study area is located at between 23.0667° N latitude and
90.6375° E longitude. It is bounded by Chandpur Sadar and Bhedarganj
upazila on the north, Hizla upazila on the south, Raipur and Faridganj
upazilas on the east, and Gosairhat upazila on the west.

7. METHODOLOGY
 Data collection- Landsat and Sentinel imageries were downloaded from the
United States of Geological Survey (USGS) website in order to analyze
riverbank erosion with WGS 1984 UTM zone 46N. And Upazila shapefile were
downloaded from the DIVA-GIS website.
 Software- ArcGIS 10.5 software and Microsoft Excel software used to
complete the research work.
 Data methods- The satellite images of 1988, 2000, 2010 and the sentinel 2A
image of 2021 were considered for image processing, image classification and
image analysis for the study. The images will be processing through NDWI and
unsupervised classification to find out the dynamic changes and erosion-
accretion of the last 33 years’ period.
Figure: Methodological framework.
Satellite
images
Layer
stake
NDWI Unsupervised
classification
Erosion &
Accretion
assessment
Map
export

8. Time table
 A timeline is a very important part of a project proposal. It basically shows
the chronological order of events that we plan to do in our project. It is
supposed to give the reader a broad overview of the project at a glance. It
does not have to be very detailed. We need to schedule our time to do a
dissertation in a time table. The target time table is given below:
 The target time of this research project is selected within 60 to 75 days.
Activity Number of Days
Topic or title selection 3
Proposal writing 12
Analysis 10
Report writing 15
Correction 10

9. FINDINGS
 From the analysis of the satellite images, I have found that there was huge
changed in the river bank and their erosion and accretion.
 The erosion rate was very high in the year between 1988 to 2000 and very low
in the year between 2010 to 2021. The accretion was very high between 2000
to 2010 and low between 2010 to 2021. So, the highest rate of the unchanged
river area was between 2010 to 2021.
Table: Erosion and accretion data from 1988 to 2021 from the satellite images.
Year Erosion (km2) Accretion (km2) Unchanged River (km2)
1988-2000 42.19 40.85 50.62
2000-2010 39.83 42.15 50.66
2010-2021 22.18 30.03 60.45
1988-2021 33.44 42.28 49.19

10. FINDINGS
▶ Here are the images of erosion-accretion of 1988-2000 and
2000-2010.

11. FINDINGS
▶ Here are the images of erosion-accretion of 2010-2021 and
1988-2021.

12. Mitigation
 For minimizing the rate of the erosion in the study area, I will discuss some
way of mitigation measures that will also lessen the impact on livelihood of
the people of the affected area.
 There are two types of mitigation measures-
 Structural mitigation measures-
 Tree plantation near the bank
area.
 Constructing embankment or
dam.
 Riprap or hard armoring which
can stabilize the riverbank.
 Non-structural mitigation measure-
 Dredging the channel for making
the area shallow which will
reduce the flow velocity.
 Re-channelized the bank area.
 Trap bag for improving barrier
system.