Aung Thura Hein
23/12/2016
Dr. Aung Zaya
23/12/2016

Aye Mya Thein

Theme: Water and Livelihood

 Topic: River Morphology changes along the Ayeyarwady River from Sagaing to

Nyaung U Township”

By Aye Mya Thein

 

 Location of the Study Area

Myanmar is situated in the mainland South East Asia with the total area of 677,000 square kilometers, which is well endowed with natural river resources of the Ayeyarwaddy, the Chindwin, the Sittaung, the Thanlwin, the Mekong and numerous small rivers. The Ayeyarwady (Irrawaddy) flows through Myanmar from the North to the South. It is the largest and longest river about 1350 miles or 2170 km long with a drainage area of about 158700 square mile or 411,000 km². The Ayeayarwady River has five major tributaries; Taping, Shweli, Myitnge, Mu and Chindwin rivers. Ayeyarwady river after passing through Mandalay turns to the right and joins with its largest tributary the Chindwin River. The study area is located in Nyaung U City & Sagaing City  between the latitudes of 21° 12′ 16″ North and 21° 55′ 37″ North, and between the longitudes of 94° 55′ 47″ East and 95° 57′ 58″ East. Its distance from Nyaung U City to Sagaing City is 83.23 miles This study took that drained through Pakokku, Myingyan, Si Mee Khon, Myimu and Ywar Thit Gyi townships The climate of the study area is tropical monsoon. Water level of all rivers in Myanmar rise at May and June. Highest water level reach during July to September and falling stage start at October. The location of study area is shown in Figure 1.

amt

Figure 1.Location of study map

  1. Situation or Problem Statement

Local people suffer from in such a way that damaged their residential land, cultivated land, livestock, socio-economic condition and health including relocation. Along the study Ayeyarwady river reach, many villages suffer from bank erosion especially within Sagaing and Nyaung U Townships during rainy season every year. The probable causes of deterioration of this are destruction of forest and vegetation coverage, high sediment input from non-perennial streams of arid zone, negligence on river conservancy, improper use of river in different aspects of river- users and insufficient river training works..The negative impacts of the situation or problem is Local people are facing with severe impacts in such a way that their residential land lost, cultivated land lost and bank erosion & sedimentation.The causes of situation or problem, these causes are coming out because of the weak awareness, no budget, ill plan, lack of knowledge, sedimentation problem and Mining. The Solution are

 

  • Providing Information & Mapping for river course changes,
  • Relocation potential settlements area
  • River Course Training (dredging/channelization of river bed)
  • Awareness to communality

 

 The positive impacts would result from the solution are

  • Formation of Agriculture Land Area
  • More Information
  • Better Planning Disaster Risk Reduction
  • Bank Protection & Prevention Sedimentation

 

What is needed to reduce/ fix the causes of the problem or situation?

  • Sharing Information & Mapping
  • Enhancement Capacity Building

 

 

 What will you do to fix the causes?

 

  • River Course Change Detection Map
  • Bank Erosion Map
  • Proposed Resettlement Map

 

What will be the change from what you will do

  • Regular monitoring on River Course Using remote sensing & GIS

       (a) Research Question

  • What are the situations during the year in 1985 – 1995, 1995-2005, 2005-2015?
  • What are the impacts on livelihoods and environment?
  • What could be provide for preventive measure or method?
  • Is it possible to extract information from Remote sensing for DM support?

 

  • Methodology

       Data Preparation and Defining the Study Area

The basic data used in this study are digital satellite images comprising of scenes for the years 1985, 1995, 2005 and 2015. In order to bring all the images under one geometric co-ordinate system, these are geo-referenced with respect to Survey of India (1:50,000 scale) topo-sheets using second order polynomial. The UTM projection and world geographic system (WGS) 1984 datum are taken for geo-referencing. The data preparation for the study is shown in Table.

       (c) Data Preparation for the Study

NO. Types of Data Year Path/Row Source
1 Landsat 7 (ETM+) 1985 133/45 & 134/45 Landsat ETM
2 Landsat 5 (TM) 1995 133/45 & 134/45         Landsat TM
3 Landsat 7 (ETM+) 2005 133/45 & 134/45 Landsat ETM
4 Landsat 7 (ETM+) 2015 133/45 & 134/45 Landsat ETM
5 Digital Elevation Model 30 m Resolution www.asterdem.com
6 Toposheets 2002 1:50000 scale Survey of India (SOI)

 In order to define the study area, required ten topographic maps are collected to cover for the reach from Nyaung U to Sagaing. Then, these topo maps are geo-referenced and combined as combined map by rectifying. Digital elevation model is clipped with this combined topo map for the study area. Flow direction, flow accumulation and watershed are calculated using Arc Map from elevation model to define study area. Boundary is extracted from watershed map to cover the study area. Flow chart for defining the study area is shown in Figure 2.

DEM Map
Flow Direction Map
Flow Accumulation Map
Watershed Map
Define Study Area

Figure  2. Flow Chart for Defining the Study Area

 In this way, river channel changes is carried out for the whole study river reach with the three periods; 1985-1995, 1995-2005 and 2005-2015. For each period, loss or deposition and gain or erosion areas are measured at every North latitude five minute interval about 9200 meter apart. The total loss and gain areas or deposition and erosion areas are also calculated. The average erosion and deposition rates are enumerated by dividing total areas of loss and gain by the period or time. The workflow of the study is shown in Figure 3.

Band 4, 3, 2

Composite

 

Unsupervised Classification

 

Extract River

(Water Body)

 

Compute Change Detection year by year

 

Measure Channel Erosion (Gain) and Deposition (Loss)
Satellite Images

Figure  3. Workflow for River Change Detection

 The changes are quantified and analyzed by the application of different tools of remote sensing and GIS softwares. Morphological changes are identified using four different years (1985, 1995, 2005, and 2015). Landsat Enhanced Thematic Mapper Plus (ETM+). False color composite i.e., band combination 4, 3, 2 is selected for unsupervised classification of Landsat imagery.

 (d) Expected Outcomes

The expected outcomes of this research are as follow:

  • River course change detection map
  • Bank Erosion map
  • Proposed resettlement Map

 

(e) Contribution

Expected outcomes will be contribute to the following organization

  • Relief and Resettlement Department (RRD)
  • Directorate of water resources and Improvement of river systems (DWIR)
  • Local and national level leaders, villagers and decision makers

REMARK: To revise the first paragraph of the Location of the Study Area; since it is same with Aung Aung Kyaw.

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