1. A.K.M. Saiful Islam Associate Professor, IWFM, BUET December 2010 Email: akmsaifulislam@iwfm.buet.ac.bd

2.  Changes of River Banks  Change detection using Satellite Images ◦ Types and sources of Satellite Images ◦ Image Acquisition Processes ◦ Image Analysis Tools: ILWIS, ERDAS ◦ ILWIS: A Open Source Software  Google Earth: ◦ As a free image source & analysis tool  Hands on Exercise using ILWIS and LandSat Images

3.  Most of the Major rivers of Bangladesh are either Meandering or Braided.  Every year, millions of people are affected by erosion that destroys standing crops, farmland and homestead land.  It is estimated that about 5% of the total Floodplain of Bangladesh is directly affected by erosion.

4. JamunaGangesPadmaUpper Megh na Lower Meghn a Averag e width (m) 19849,7204,3675,6893,4066,661 1993*11,2204,6937,1163,3918,897 Rate of change of width (m/yr) 184361592248 Changes during 1984-93 Jamun aGanges Padm a Upper Megh na Lower Megh na Bank erosio n rate (m/yr) Left *100-2038766 Right*8456121-9182 Maximum bank erosion rate (m/yr)*784665620NA824 Bank erosion (ha/yr)*5,0202,2401,800481,172 Bank accretion (ha/yr)*8901,01023349402 Change of width of the rivers Source: ISPAN, 1995 Note: * Rates derived for the period 1984-92

5. Teesta River at Sundarganj

6.  Satellite data is useful for monitoring changes of Bank lines.  However, careful inspection and Ground Truthing is necessary to verify the changes.  Using images of various Bands, False Color Composite images are developed to identify various features of the landscape.

7. True Color CompositeFalse Color Composite image

8. Spectral Images can be used  Low resolution (<=1km): ◦ NOAA, MODIS  Moderate resolution (<100m): ◦ Landsat, SPOT  High resolution (<5m): ◦ ICOKON, Quickbird, IRS, World View-2

9. Spectral Reflectance of Water, Vegetation, Soil and Rock 123457 TM

10.  Landsat-7  Orbit: 705 km, 98.2 0 inclination, sun-synchronous  Swath width: 185 km (FOV = 15 0 )  Revisit time: 16 days  Spatial resolution: 15 m (PAN), 30 m (bands 1-5, 7), 60 m (band 6)  SPOT-1, 2, 3, 4  Orbit: 832 km, 98.7 0 inclination, sun-synchronous  Swath width: 60 km  Revisit time: 26 days  Spatial resolution: 10 m (PAN), 20 m (Multispectral)

11.  SPOT-5 Orbit: 822 km, 98.7 0 inclination, sun-synchronous Swath width: 60 km Revisit time: 2-3 days Spatial resolution: 5 m (PAN) 10 m (Multispectral)  IKONOS Orbit: 681km, 98.20 inclination, sun-synchronous Swath width: 11km Revisit time: 1-3 days Spatial resolution: 1m (PAN), 4 m (Multispectral)

12. QuickBirdWorldView-1WorldView-2 23 m6.5 m QuickBirdWorldView-1WorldView-2 Panchromatic (B&W) 450 - 900 nm400 - 900 nm450 - 800 nm Multispectral: Coastal Blue 400 - 450 nm Blue450 - 520 nm 450 - 510 nm Green520 - 600 nm 510 - 580 nm Yellow 585 - 625 nm Red630 - 690 nm Red Edge 705 - 745 nm Near-IR 1760 - 900 nm 770 - 895 nm Near-IR 2 860 - 1040 nm

13.  High Resolution images need to be purchased.  However, some of the moderate resolution images can be downloaded freely.  Landsat TM and ETM images can be downloaded from USGS Global Visualization Viewer.  MODIS Images can be downloaded from LP DAAC web site at https://lpdaac.usgs.gov/lpdaac/get_data/wist https://lpdaac.usgs.gov/lpdaac/get_data/wist

15. 11 November 19894 November 2005

16. BankShifting of bankline from base year (1989) to present year (2010) in meter Left BankRight Bank At the bridge Location -198.94+240.8 1 km upstream -157.16+190.5 1 km down stream -34.2+67.35

17. November 11, 1989November 17, 2000 November 04, 2005January 21, 2010

20. February 19, 2006 February 27, 2004

21. Shifting of bank line from base year (2004) to present (m) At the bridge Location -1.916.2 1 km upstream-1.315.3 1 km down stream -2.915.3

22. A.K.M. Saiful Islam IWFM, BUET

23.  Input Data: ◦ Landsat Images of Year 1989 and 2010 of Band 1-4 ◦ Bridge Location Text File (Lat, Long)  Software: ILWIS 3.7  Assignment: ◦ Develop False Color Composite Images ◦ Show the location of the Bridge Site ◦ Determine the Bank lines during 1989 and 2010 ◦ Detect Changes of Banks

26.  Import Bridge Location Text File “Bridge_Sundar_Teesta.txt”  It will imported as Table  Create a Point Map from the Table  Assign coordinate as “Lat-Lon” Longitude, Latitude 90.33028611, 23.09426389

27.  Use Import Wizard, Select Text files, Press Next Button

28.  Import as “Comma Delimited” ILWIS Table

29.  Skip 1 Lines as Header

30.  Change domain as “value”  Change precision as “1e-006”

31.  Finish importing table “kalkini_bridge”

32.  Open Table, Column1 as longitude and Column 2 as Latitude Create Point Map from the Table by Clicking right mouse > Table to Point Map

33.  X Column as Long and Y Column as Latitude  Coordinate System as LATLON  Output PointMap “Kalkini_Bridge” > Show

34. Shows Bridge location As point map

35.  Band 1, 2, 3, 4, 5, 6, and 7 in folder 2010 and 1989  Import using via GDAL as TIF format Band 1-7 as TIF images Import Geo-Tif Images to ILWIS format

36.  Import using TIF format and write file name Change image format as (TIF) and give a name

38.  Import Band 1 to 7 using the same tools with and save file name as b1 to b7.  Make a Map List using Band 1 to 7.

39.  Make map list using “>” and name it as “maps” Add all 7 layers to create a maplist “Maps”

40. Use display tool Select band 7-4-2 as RGB

41. False color composite of landsat image

42. Use add layer button Select bridge point map and add it

43. Change color to red Location of the bridge in red color

44. Use zoom tool Zoom the map over bridge site

45. Create new segment For bank lines Write segment names

46. Change tolerance Values to small value Customize Using right Mouse button

47. Start digitizing using Insert tool and then save Insert tool

48. Bank lines in 2010 Bank lines in 1989

49. Field visit to the bridge site Changes over 21 years

50. BankShifting of bank line from base year (2000) to present year (2005) in meter At the bridge Location -332+398.57 1 km upstream -266.55+389.108 1 km down stream -121.33+206.10