Application of Satellite Based Geoinformation TechnologyIntegrated with GIS for Monitoring and Understanding the          ...
ACKNOWLEDGEMENTI am very much obliged to many individuals who have contributedto the development of this thesis.At first I...
SummaryBangladesh is a disaster prone country. Cyclone, Tornado, Hailstorm, Drought and theflood are the most well known i...
Contents1. Introduction .....................................................................................................
5.3.1 Geography ........................................................................................................ 2...
1. Introduction1.1 IntroductionFlood and cyclone are the two most common and frequently occurred events inBangladesh that ...
Fig. 1: Location map of Bangladesh1.2 Aims and ObjectivesIn this section the aims of the research are identified. The prim...
2. Physical Features of Bangladesh2.1 Climatic ConditionBangladesh lies between 20o 34. and 26° 38. north, between 88° 01....
2.3 HydrologyBangladesh has unique hydrological regime. It has been divided into 7 hydrologicalzones. Hydrological zones a...
2.5 Land TypesIn order to understand the flooding and flood management, it is better have look into theland types. Seasona...
3. River System, Statistics of Flood & Cause of Flood ofBangladesh3.1 Bangladesh River SystemThe Ganges originates near th...
Fig. 3: River system of Bangladesh                                Salah Uddin | 032013
Rivers of different morphological characteristics e.g. meander, braided, incise etc. arefound in this country. Major river...
3.2 Statistics of Bangladesh FloodBangladesh is very much affected by flood. The following table provides information onim...
1983                           11.0                          1984                           27.9                          ...
carrying capacity of the rivers flood results. The magnitude of the flood depends on themagnitude of excess water that is ...
It is estimated about 2.4 billion tons of sediments are carried by the river systemof Bangladesh every year and part of th...
4. Materials & Methods4.1 Data UsedIn the present study, remote Sensing (RS) and Geographical Information System (GIS)have...
Landsat travels along a sun synchronous orbit over the North and South poles, at roughlyright angles to the equator, at an...
4.1.4 Agricultural statistics and population census data   -   Historical crop yield data and population census supplied b...
•     Finalization of pre-flood raster layer.- Phase 3: Generation of various thematic layers containing information on ro...
-   Combination of vector layers obtained from all the images.   -   On-screen editing of the vector data.   -   On-screen...
processing procedures are categorized into the following types of computer-assistedoperations.   A) Image processing: This...
The present study has been supplemented by extensive field investigation over someselected locations in the study areas. T...
5. Study Area                                                                    N                                        ...
5.1 Chandpur DistrictChandpur is a district in east-central Bangladesh. It is located at the mouth of theMeghna River. It ...
5.2.2 SubdivisionsIt consists of 4 upazilas, 3 municipalities, 30 wards, 55 mahallas, 47 union parishads, 445mouzas and 53...
5.3.2 SubdivisionsNoakhali district, whose earlier name was Bhulua, was established in 1821. It consists ofeight upazilas,...
6. Flood Reports of the study areas (non-flood period & floodperiod)6.1 Non-flood period Report                           ...
The following tables (Table 5, Table 6 & Table 7) shows the informations about Non-flood period of Chandpur, Lakshmipur & ...
6.2 Flood Report, July 7, 1998The following tables (Table 8, Table 9 & Table 10) shows the informations about floodperiod ...
6.3 Flood Report, September 10, 1998             Legend                                                          N        ...
The following tables (Table11, Table 12 & Table 13) shows the informations about floodperiod of September 10, 1998 of Chan...
6.4 Flood Report, August 25, 1998The following tables (Table14, Table 15 & Table 16) shows the informations about floodper...
7. Result & DiscissionsThe first phase of the study was carried out with objectives such as, monitoring floods asaccuratel...
7.1 Vulnerability of FloodComparision between non-flood period & Flood period dataIn non-flooded period the water areas of...
Fig: 6 shows the daily water discharge in m3/sec of the river Meghna at the BhairabBazar measuring station near the presen...
8. ConclusionThis thesis work has been carried out for the partial fulfillment of the requirements forBachelor of Sciences...
In the following a number of specific remark has been made:       The study areas (Chandpur, Lakshmipur & Noakhali) are th...
9. References     Information for Flood Management in Bangladesh: Main Report, Riverside     Technologies Inc. and Environ...
10. AppendixList of FiguresFig. 1: Location map of BangladeshFig. 2: Hydrological zones of BangladeshFig. 3: River system ...
Table 15 : Information about flood period of August 25, 1998 of Lakshmipur districtTable 16 : Information about flood peri...
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Application of Satellite Based Geoinformation Technology Integrated with GIS for Monitoring and Understanding the Flood Phenomenon in Bangladesh

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Application of Satellite Based Geoinformation Technology Integrated with GIS for Monitoring and Understanding the Flood Phenomenon in Bangladesh

  1. 1. Application of Satellite Based Geoinformation TechnologyIntegrated with GIS for Monitoring and Understanding the Flood Phenomenon in Bangladesh A thesis submitted for the partial fulfillment for the award of Bachelor of Sciences (B.Sc.) Degree in Information Technology By Mohammad Salah Uddin Id: 032013 Supervised by Prof. Dr. Hafizur Rahman Formaer Head, School of Computer Science & Engineering And Principal Scientific Officer (PSO)Bangladesh Space Research and Remote Sensing Organization (SPARRSO), Agargaon, Shere Bangal Nagar, Dhaka-1207, Bangladesh. Cell:+8801715012025 ,Email: hafiz1961@yahoo.com Term: Spring 2007 School of Computer Science & EngineeringUniversity of Information Technology & Sciences (UITS) Salah Uddin | 032013
  2. 2. ACKNOWLEDGEMENTI am very much obliged to many individuals who have contributedto the development of this thesis.At first I would like to express thanks to our honorable andsagacious supervisor, Prof. Dr. Hafizur Rahman, Head School ofComputer Science & Engineering, University of InformationTechnology & Sciences (UITS), for his generous help,encouragement, constant guidance, enthusiasm and wholeheartedsupport throughout this thesis for its successful completion.Sincere appreciation to Fida Ashfaq Ahmed, Marufa Tahmid & RidfaRahman, students of IT, for their wholehearted help andencouragement to complete this thesis.In addition to the above mention, I am aware of the direct andindirect contributions of many others towards achieving the successof this thesis work. I am sincerely thank all them.Finally, I would like to thank all the teachers of the Schools ofComputer Science & Engineering and all the students of ourDepartment for their cooperation and support to complete the thesis. Salah Uddin | 032013
  3. 3. SummaryBangladesh is a disaster prone country. Cyclone, Tornado, Hailstorm, Drought and theflood are the most well known issues in terms of disaster. For the last two decades, spaceborne remote sensing along with other geo-spatial technology (e.g., GIS) has beenappeared to be as an effective tool for monitoring of such surface events that contributedsignificantly to reduce the losses of lives and properties of the people living in the area.In the present work, multitemporal data acquired by the ScanSar (sensor) on board theCanadian satellite RADARSAT has been used to monitor flood in Bangladesh. GIS aidedanalysis of RADARSAT image coupled with various hydrological data regarding rainfall,river water level and river water discharge have been performed to study the dynamics offlood in the spatiotemporal domain. Detailed analysis has been made on the floodsituation in relation to landform, surface topographic characteristics etc. over someselected districts. Investigation has been made to study the correspondence betweenprogressive devastation and evolution of flood situation in the country.Assessment of aerial extent of flood causing damages and casualties to agricultural crops,land and urban areas has been attempted. Basin-wise investigation on the riverhydrographs in relation to flood extent as derived from time series RADARSAT datahave been analyzed. Analysis of time series Geostationary Meteorological Satellite(GMS) data has been used to provide the cloud cover condition and possible rainfall overthe region both inside the country and its outside upstream regions during the mentionedperiod. Analysis of water level data has been incorporated to the analysis to understandand interpret the variation of water levels in the river areas including Ganges,Brahmaputra and Meghna. GIS-based operation has provided area-wise crop underdifferent damage categories. Comparison of river hydrographs with satellite derivedinundated areas has been made to show the correspondence between the two. GIS-aidedspatial analysis of the pre-flood and post-flood imageries provides area-wise actualflooded areas. Salah Uddin | 032013
  4. 4. Contents1. Introduction ..................................................................................................................... 6 1.1 Introduction ............................................................................................................... 6 1.2 Aims and Objectives ................................................................................................. 72. Physical Features of Bangladesh ..................................................................................... 8 2.1 Climatic Condition .................................................................................................... 8 2.2 Topography ............................................................................................................... 8 2.3 Hydrology.................................................................................................................. 9 2.4 Soils ........................................................................................................................... 9 2.5 Land Types .............................................................................................................. 103. River System, Statistics of Flood & Cause of Flood of Bangladesh ............................ 11 3.1 Bangladesh River System........................................................................................ 11 3.2 Statistics of Bangladesh Flood ................................................................................ 14 3.3 Causes of flood in Bangladesh ................................................................................ 154. Materials & Methods ..................................................................................................... 18 4.1 Data Used ................................................................................................................ 18 4.1.1 Remote sensing data ......................................................................................... 18 4.1.2 Ancillary data ................................................................................................... 19 4.1.3 Agro climatic data ............................................................................................ 19 4.1.4 Agricultural statistics and population census data ........................................... 20 4.2 Software Used ......................................................................................................... 20 4.3 Methodology ........................................................................................................... 20 4.3.1 Preparation of Base Layer ................................................................................ 21 4.3.2 Field data collection and verification ............................................................... 22 4.3.3 Post fieldwork .................................................................................................. 22 4.3.4 Other Processing .............................................................................................. 225. Study Area ..................................................................................................................... 25 5.1 Chandpur District .................................................................................................... 26 5.1.1 Geography ........................................................................................................ 26 5.1.2 Subdivisions ..................................................................................................... 26 5.2 Lakshmipur District................................................................................................. 26 5.2.1 Geography ........................................................................................................ 26 5.2.2 Subdivisions ..................................................................................................... 27 5.3 Noakhali District ..................................................................................................... 27 Salah Uddin | 032013
  5. 5. 5.3.1 Geography ........................................................................................................ 27 5.3.2 Subdivisions ..................................................................................................... 286. Flood Reports of the study areas (non-flood period & flood period) ........................... 29 6.1 Non-flood period Report ......................................................................................... 29 6.2 Flood Report, July 7, 1998 ...................................................................................... 31 6.3 Flood Report, September 10, 1998 ......................................................................... 32 6.4 Flood Report, August 25, 1998 ............................................................................... 347. Result & Discissions ..................................................................................................... 35 7.1 Vulnerability of Flood ............................................................................................. 36 7.2 Flood affected areas calculation in 25th August 1998 ............................................. 378. Conclusion..................................................................................................................... 389. References ..................................................................................................................... 4010. Appendix ..................................................................................................................... 41 List of Figures ............................................................................................................... 41 List of Tables ................................................................................................................. 41 Salah Uddin | 032013
  6. 6. 1. Introduction1.1 IntroductionFlood and cyclone are the two most common and frequently occurred events inBangladesh that cause significant damages and casualties to the lives and properties ofthe people. Bangladesh is perhaps the unique country in the world where casualties due toa cyclone could rise up to hundreds of thousands. Flood can devastate more than half ofthe country causing damages to billions of dollars. The rate of visit of all these naturaldisaster varies from year to year and the amount of losses and damages depends on theintensity and the length of occurrence period.During the last half century at least 9 nos. of extreme flood events occurred affecting50% of land area. Since early sixties of the last century the country has adopted differentkinds of measures for flood management with mixed experiences.A location map of Bangladesh is given in fig. 1. Because of its unique geographicallocation and topography, flood of different magnitudes and types occurs every year.Table 1: Important flood events in Bangladesh Year 1954 1955 1956 1962 1963 1987 1988 1998 2004Flooded area 36400 49900 35100 39600 42500 56600 818000 83000 57000 (Sq. Km) Salah Uddin | 032013
  7. 7. Fig. 1: Location map of Bangladesh1.2 Aims and ObjectivesIn this section the aims of the research are identified. The primary objectives of theresearch is to observe the flood Phenomenon in Bangladesh during summer period. Indetail, the following objectives are set. Causes of flood in Bangladesh. Comparision between non-flood period & Flood period by collecting Field data and verification. And find the effects of flood Salah Uddin | 032013
  8. 8. 2. Physical Features of Bangladesh2.1 Climatic ConditionBangladesh lies between 20o 34. and 26° 38. north, between 88° 01., and 92° 41. east. Itsclimate is tropic and humid. It has mainly four seasons, e.g. Pre-monsoon (March toMay), Monsoon (June to September), Post monsoon (October to November), Dry(December to February). Its climate is influenced by the Indian monsoon. Averagerainfall is 2200-2500 mm but the range of which is between 1200 to 6500 mm. 80% ofthe rainfall occurs during monsoon i.e. from June to September. Average temperature isaround 30 C except during the dry season.2.2 TopographyTopography is mostly flat excepting some part in the northeast and southeast, which arehilly. Entire country was formed due to sedimentation of the large river systems e.g.Ganges, Brahmaputra & Meghna. Land Elevation ranges from -3m to 60 m in the plainsand in the hilly areas land elevation varies from100 to 1000 m. Salah Uddin | 032013
  9. 9. 2.3 HydrologyBangladesh has unique hydrological regime. It has been divided into 7 hydrologicalzones. Hydrological zones are shown in the following figure. Fig. 2: Hydrological zones of Bangladesh2.4 SoilsA total of 483 soil series was identified and described in the Soil Reconnaissance Surveyof Bangladesh. It does not include Sunderban, a mangrove forest, and Chittagong Hilltracts. General soil types are differentiated into three physiographic groups, e.g.floodplain soils, Terrace soils and Hill soils. Floodplain soils have been formed inalluvial sediments from a few months to several thousand years. General pattern offloodplain soils is of sandy or loamy soils on higher parts of floodplain ridges into clay inthe adjoining basins. Terrace soils comprises of a wide range of soils formed over theModhupur Clay. Soil differences are due to differences in drainage and in depth anddegree of weathering. Hill soils include a wide range of soils formed over consolidatedand unconsolidated sandstones, siltstones and shale. Salah Uddin | 032013
  10. 10. 2.5 Land TypesIn order to understand the flooding and flood management, it is better have look into theland types. Seasonal flooding regime has been characterized by means of inundation landtypes. Usually, it is classified into 5 categories and detailed description of land type withthe area coverage is given in Table 2. Table 2: Land Types information of BangladeshLand Type Description Area in ha % AreaHigh Land Land above normal inundation 4199952 29Med. High Land Land normally inundated up to 90 cm deep 5 039 724 35Med. Low Land Land normally inundated up to 90-180 cm 1 771 102 12 deepLow Land Land normally inundated up to 180-300 cm 1 101 560 8Very Low Land Land normally inundated deeper than 300 cm 193 243 1Total Soil Area 12 305 85 581River, Urban etc. 2 178 045 15From the land types it is evident that except high lands all other land types are subjectedto flood inundation to different degrees. Normally, 20-25% of the country is inundatedduring every monsoon from June to September. In case extreme flood events 40-70%area can be inundated which was amply proved during the extreme flood events of 1954-55, 1974, 1987-88 and 1998. All kinds of land type are distributed all over the country.High lands are situated in some parts of the western, south central, northeastern andsoutheastern regions of the country. Excepting very low lands, human settlements can befound in all other land categories. Of course population density is high in the MediumHigh and Medium Low Lands. People live in the Low Lands building earthen mounds. Salah Uddin | 032013
  11. 11. 3. River System, Statistics of Flood & Cause of Flood ofBangladesh3.1 Bangladesh River SystemThe Ganges originates near the Gangotri Glacier of the Himalayes with an elevation ofover 23,000 ft and has a length of about 1600 miles. It receives the flow of a number ofmajor tributaries namely Gogra, Gandak and Kosi originates in Nepal and Tibet. Anothertributary of the Ganges, the Mohananda, which flows through Bangladesh, originates inIndia. The catchments area of the Ganges is about 3,50,000 square miles spread over fourcountries namely China, Nepal and Bangladesh.The Brahmaputra originates in Tibet and has a length of about 1800 miles upto itsconfluence with Ganges. It flows under the name of Tsangpo in Tibet north of theHimalayan range for a distance of 700 miles. It turns south under the name of the Dihangand is joined by its main tributaries the Dibang, the Lohit and the Dihing. It then flowswestwards down the Assam valley as Brahmaputra, thereafter it enters Bangladesh(where the main flow is known as Jamuna) and is joined by Dharala at Kurigram andTista at Chilmari. The catchment area of he Brahmaputra is about 2,24,000 square milesand is spread over China, India, Bhutan and Bangladesh.The Meghna is formed by the confluence of the Surma and Kushiara together with otherstreams from hills in the northeast. The Surma is fed mainly by the tributaries from JaintaHills while Kushira is fed by tributaries from Tripura hills. The Meghna system is about500 miles long of which about 260 miles lies in Bangladesh and the rest in India. Thetotal catchments area of the Meghna above Bhaira Bazar is about 25,000 square miles ofwhich about 32% lies in Bangladesh. Salah Uddin | 032013
  12. 12. Fig. 3: River system of Bangladesh Salah Uddin | 032013
  13. 13. Rivers of different morphological characteristics e.g. meander, braided, incise etc. arefound in this country. Major rivers having length of 500 to 2500 km and width rangefrom 1km to 20 km can also be found in this country. Water surface slopes of the majorrivers are also very flat e.g. av. slope of Ganges is 5-6 cm/km, av. slope of Brahamaputrais 8-9 cm/km and av. slope of Meghna is 4-3.5 cm/km. Annual flow volume of the riversis to the tune of 1200 billion cum. Rivers of Bangladesh carries huge sediment annualamount of which is between 1.8 to 2.0 billion tons. A picture of annual flow cycle ofthree major rivers at three selected locations e.g. Ganges at Hardinge Bridge,Brahmaputra at Bahdurabad and Meghna at Bhairab Bazar are presented in the fig. 4, fig.5, fig. 6 respectively. Salah Uddin | 032013
  14. 14. 3.2 Statistics of Bangladesh FloodBangladesh is very much affected by flood. The following table provides information onimportant flood events in Bangladesh along with inundated areas. Table 3: Statistics of Flood events in Bangladesh Year Thousand Sq. Km. 1954 36.4 1955 49.9 1956 35.1 1960 28.2 1961 28.4 1962 36.9 1963 42.5 1964 30.7 1965 28.2 1966 33.2 1967 25.3 1968 36.3 1969 41.0 1970 42.0 1971 35.8 1972 20.5 1973 29.4 1974 52.0 1975 16.4 1976 27.9 1977 12.3 1978 10.8 1980 32.5 1982 3.1 Salah Uddin | 032013
  15. 15. 1983 11.0 1984 27.9 1985 11.3 1986 3.1 1987 56.6 1988 81.8 1989 6.1 1990 3.5 1991 28.6 1992 2.0 1993 28.7 1994 0.42 1998 85.03.3 Causes of flood in BangladeshThe primary cause of flood in Bangladesh is rainfall in the catchments areas of the riversof Bangladesh. Situated in the monsoon belt with the Himalayes in the north, Bangladeshfalls in the region of very heavy rainfall. About 80 percent of the rainfall occurs duringthe 5 months period from May to September.The annual rainfall varies from about 60 inches in the western part of the country to about200 inches in the northeastern part. At Cherepunje in Assam very near our Sylhet Borderthe average annual rainfall is about 500 inches, which is highest in the world. But theaverage rainfall in Bangladesh generates annually only 100 million acre to water whereas1100 million acre feet of water comes from outside Bangladesh. Thus about 90 percent ofthe water carried by our river system, the Brahmaputra, the Ganges, the Meghna andother smaller rivers is brought from outside the country. These rivers carry water from anarea of about 6000000 sq miles of which only 7.5 percent lies in Bangladesh. Waterenters in Bangladesh through three major channels but the discharge takes place throughone major channel. The river system has evolved to carry the normal flow of watergenerated in the catchments area. Whenever the inflow of water is greater than the Salah Uddin | 032013
  16. 16. carrying capacity of the rivers flood results. The magnitude of the flood depends on themagnitude of excess water that is generated.It must be remembered that flood in Bangladesh is caused by rainfall in the catchmentareas of the river systems of Bangladesh, 92.5 percent of which lies outside it, namely inIndia, Nepal, Bhutan and Tibet (China). Thus though there may not be mush rainfalllocally, there may be heavy rainfall in the catchment area causing flood. In these days,with the help of weather satellite imagery, rainfall in the whole year that is responsiblefor flood catchment area can be monitored. Again it is not the rainfall for the whole yearthat is responsible for flood. The rainfall for the whole month or the year may be normalbut if a whole month’s rainfall in the whole catchment area occurs over a matter of fewdays and if the soil is already satured because of previous rainfall, severe flooding mayresult. It is difficult to imagine the nature of rainfall in hilly areas where most of thecatchment areas of Bangladesh rivers lie. Whereas the average annual rainfall at Dhaka isabout 80 inches, that at Cherapunjee is 500 inches and the maximum rainfall atCherapunjee is 900 inches a year. That means in hilly areas rainfall could be as much asten times that in the plains of Bangladesh.Besides the primary cause, namely rainfall in the catchment area, there are other factors,which may aggravate the floods. They are: Snow melting in the Himalayes can also contribute towards flood. However, maximum flooding occurs in Bangladesh during August-September whereas maximum snow melt occurs probably during May-June and as the snow melting process is normally quite slow, this alone may not be a great factor in causing flood in Bangladesh. However, as rainfall itself accelerates the process of snow melt, the contribution of snow-melting as a factor in flood may not be entirely negligible. More research needs to be done in this field. It is understood that considerable hydrographic changes have taken place in the region specially in the Brahmaputra basin as a result of 1950 earthquake in Assam. This has resulted in the rise of the bed of Brahmaputra river in the upper reaches, thus reducing the carrying capacity of the river. This may be one of the reasons for increase of flood frequency in Bangladesh after 1950. Salah Uddin | 032013
  17. 17. It is estimated about 2.4 billion tons of sediments are carried by the river systemof Bangladesh every year and part of this sediment is deposited in river beds. Thisthe rivers, which worsen the flood. As a matter of fact many of the past activerivers have ceased to be active in the dry season.The catchment areas of the rivers of Bangladesh are being denuded of forests atan alarming rate. The soil in the catchment area which was covered by forestspreviously is becoming bare. Forest covered soil absorbs part of the rain water butbare soil absorbs less water and consequently run off is more. Thus deforestationin the catchment area tends to aggravate the flood.Constructions of unplanned roads, railways, barrages, embankments etc. may alsocreate obstacles to the flow of water and may, to a certain extend, aggravate theflood.Because of the southwest monsoon wind, the mean sea level rises by about twofeet during summer. If there are depressions in the Bay of Bengal and themagnitude of the wind is more, the sea level may rise further creating obstacles tothe river flow thus aggravating the flood.High tide occurs new and full moon twice every month. Of the flood peak occursduring high tide time, aggravation of the flood may result. Moreover, if the moonis at perigee that is at the nearest distance from the earth, tide could be more andflood could further worsen. Salah Uddin | 032013
  18. 18. 4. Materials & Methods4.1 Data UsedIn the present study, remote Sensing (RS) and Geographical Information System (GIS)have been used for monitoring flood in Bangladesh. The aim of this study is to assess theland qualities, land characteristics and land requirements of various land utilization typesfor optimal land use planning. For the present study following data set are used.4.1.1 Remote sensing dataSensor characteristics are very important in the utilization of satellite data for a particularpurpose. The interaction of solar radiation with plant and other earth’s surface materialsare very important. The spectral, temporal and radiometric properties play significant rolein determining the signal at satellite altitude.Characteristics of Landsat TMTable 4 provides the basic characteristics of Landsat TM. It has a total of seven relativelynarrow spectral bands. Table 4: Basic sensor characteristics of Landsat TM Channel Description Band widths (um) Spatial resolution1 Blue 0.45 – 0.52 30m2 Green 0.52 – 0.60 30m3 Red 0.63 – 0.69 30m4 Near-Infrared 0.76 – 0.90 30m5 Middle Infrared 1.55 – 1.75 30m6 Thermal Infrared 10.4 – 12.5 120m7 Infrared 2.08 – 2.35 30m Salah Uddin | 032013
  19. 19. Landsat travels along a sun synchronous orbit over the North and South poles, at roughlyright angles to the equator, at an altitude of about 700km. They circle the earth 15 times aday, and return to their starting point every 16 days. Observed data are provided in 185kmX170 km scenes.Satellite Imageryi. Satellite/ Sensor : Landsat Thematic Mapper (TM) Projection : Lambert Conformal Conic (LCC) Path/Row : 136/043ii. RADARSAT / NOAA Data4.1.2 Ancillary data - Topographic Map: Prepared by Survey of Bangladesh (SOB), Topo sheet No. 78 P/4, 78 P/8, 78 P L/16, Scale 1:50,000. - Administrative map of Bangladesh, Scale 1:1000000. - Soil map prepared by Soil Resources and Developed Institute (SRDI), Dhaka, Bangladesh, Scale: 1:50,000. - Soil nutrient from Soil Resource Development Institute (SRDI) - Land reconnaissance map of 1967.4.1.3 Agro climatic data - Rainfall and temperature data supplied by the Bangladesh Metrological Department (BMD), Bangladesh. Salah Uddin | 032013
  20. 20. 4.1.4 Agricultural statistics and population census data - Historical crop yield data and population census supplied by the Bangladesh Bureau of Statistics (BBS), Dhaka, Bangladesh.4.2 Software UsedThe methodology adopted for this study involves both the Digital Image Processing(DIP) and GIS based analysis. DIP was carried out in the computer system having thefollowing software configuration. - PC-based ERDAS IMAGING Image Processing Software. - PC-based Arc Info Software. - Microsoft Excel. - MGI Photo Suite.4.3 MethodologyThe whole work has been performed according to the following phases:- Phase 1: Pre-processing and preparation of satellite data • Geometric Correction of Satellite images. • Geo-referencing. • Cloud screening of digital images • Digital mosaic and subset operation- Phase 2: Preparation of reference raster layer for pre-flood and flood conditions • Spatial characteristics and identification of different object classes in digital images. • Digital classification of raster image • Threshold operation to climate statistically insignificant sized object clusters. • Regrouping operation to climate statistically large number of object classes into a limited number of meaningful thematic classes. Salah Uddin | 032013
  21. 21. • Finalization of pre-flood raster layer.- Phase 3: Generation of various thematic layers containing information on road network,infrastructures, settlement, agricultural areas etc. from satellite data and existing maps ofthe area.- Phase 4: GPS (Global Positioning System) based field survey operation for field datacollection, verification, and correction of interpreted thematic raster layer.- Phase 5: Generation of class statistics4.3.1 Preparation of Base LayerBase map preparation: Using topographic maps and satellite images of different physical,cultural and thematic information have been depicted for the preparation of spatial layers.And the thematic layers provide information about major communication network,agricultural pattern, river & canal, settlement etc.Preparation of base mapsBase map of the study are has been prepared using SPOT data. Visual interpretation ofthe images was performed using the most important diagnostic characteristics, includingshape, size, tone/color, texture, contrast and pattern. The drainage system and land coverof the study area is also considered during interpretation. The geographic references andgradients are taken from top sheets 1:50,000 scales prepared by Survey of Bangladesh(SOB).The general techniques used to obtain macro-structure land use classes in vector fromwere: - Unsupervised classification of merged image as well as Landsat TM image. - Merging the classes to the desired number of classes. - Elimination of non-homogeneity and noise using 7X7 majority spatial filter. - Raster to vector: transformation. Salah Uddin | 032013
  22. 22. - Combination of vector layers obtained from all the images. - On-screen editing of the vector data. - On-screen editing of the vector layer was needed to correct classification error, as well as to well shape the structures of he features, Micro-structured features were digitized on-screen from the images, as well as from the base maps.Interpretation of landsat/land cover mapUsing temporal Landsat TM digital data landuse/land cover were recognized throughdigital processing.4.3.2 Field data collection and verificationInitially to understand the broad landforms and landuse a reconnaissance survey wasunder taken. Through the fieldwork the landuse map of the study area were corrected. Todo the fieldwork easily topographical map at the scale 1:50,000 were used.4.3.3 Post fieldworkAfter the fieldwork digitally classified Rabi and Kharif seasons landuse/land cover mapswere corrected and for final analysis the above maps were brought in the ARC/INFO GISenvironment.4.3.4 Other Processingi) Digital Image ProcessingRemotely sensed imagery data in suitable format is freely accessible for digitalprocessing, Spatially the data is composed of discrete picture elements or pixels, andradiometrically it is quantized into different discrete brightness levels. The numeric valueof a pixel represents the average brightness of surface of pixel area. Digital image Salah Uddin | 032013
  23. 23. processing procedures are categorized into the following types of computer-assistedoperations. A) Image processing: This involved the initial processing of the image to correct for geometric distortions, to calibrate the data rediometrically and eliminate the noise present in the data. All the images were projected to Lambert Conformal Conic (LCC) system. The images were almost cloud free over the Bangladesh area and have reasonably good contrast. B) Image Enhancement: This procedure is applied to image data in order to increase the visual distinction between features in an image. The objective is to create new images from the original images so as to increase the amount of information extracting that can be interpreted or used for further analysis by computers. Three broad classes of problems to be considered in image enhancement are: i) Contrast Manipulation ii) Spatial features manipulation iii) Multi image manipulation. C) Image Analysis and Identification: The interpretation of digital imagery may be quantitative or qualitative. In quantitative analysis much of the interpretive work is left to the computer, such as in image classification. In qualitative analysis, an analyst uses the computer to improve the interpretability of the image. The objective of this operation is to replace visual analysis of the image data with quantitative techniques as for automating the identification of features in the image by computer. Image analysis techniques require extraction of certain features that aid in the identification of the object. Segmentation techniques are used to isolate the desired object from the scene.In the present work, both supervised and unsupervised techniques of classification havebeen employed. An image has been classified into different categories depending on theinterest of surface features or different zones of the study area. Classification has beenperformed using ERDAS IMAGINE interpreter modeler where signature editor is theprimary step that helps to been conducted and chooses maximum likelihood forparametric rules to get the desired classes. Then recoding has been done and differentland features classes were assigned after studying the spectral profile.ii) GPS Based Ground Survey Salah Uddin | 032013
  24. 24. The present study has been supplemented by extensive field investigation over someselected locations in the study areas. The purpose of the survey was to verify the resultsof classification and regroup the classified areas into a limited number of significantclasses representative of major surface classes of the area.In this step, areas belonging to different class categories have been selected from theclassified image and have been taken as a basis for field investigation. A globalpositioning system (GPS) (GeoExplorer 11, Trimble) has been used to locate each ofthese selected areas with a good precision. Then detailed observations on the locationshave been made over each of these selected areas. Such a step based on a limited numberof ground observations provided an interpretation key to classify the study.iii) Application of GISIn the present study, various thematic information have been used in the analysis of landsuitability. Spatial data on land type distribution, surface elevation etc. have beenincorporated into Geographic Information System (GIS) database. A district boundaryvector layer has been generated from a 1:1000000 administrative map of Bangladeshusing the GIS. This vector layer is used for the calculation of district crop statistics fromthe classified images. Finally, all these data are combined with the thematic information.The objective analysis much of the interpretive work is left to the computer, such as inimage classification. In qualitative analysis, an analyst uses the computer to improve theinterpretability of the image. The objective of this operation Salah Uddin | 032013
  25. 25. 5. Study Area N O R T H Fig 7 : Map of Study Areas Salah Uddin | 032013
  26. 26. 5.1 Chandpur DistrictChandpur is a district in east-central Bangladesh. It is located at the mouth of theMeghna River. It is a part of the Chittagong Division.5.1.1 GeographyChandpur district has a total area of 1704.06 square kilometers. It is bounded byMunshiganj District and Comilla District on the north, Noakhali District, LakshmipurDistrict and Barisal District on the south, Comilla District on the east, and Meghna River,Shariatpur District and Munshiganj District on the west.Chandpur is the confluence of two of the mightiest rivers of Bangladesh .. the PadmaRiver (the main branch of the Ganges River) and the Meghna River, which meet nearChandpur Town. Important tributaries of the Meghna River flowing through Chandpurare Dakatia River, Dhanagoda River, Matlab River and Udhamdi River.5.1.2 SubdivisionsChandpur has 6 municipalities, 60 wards, 195 mahallas, 7 upazilas, 1 thana, 87 unionparishads and 1226 villages. The municipalities are Chandpur Sadar, Shahrasti, Matlab,Changer Char and Hajiganj. The administrative subdivisions called upazilas areChandpur sadar, Hajiganj, Kachua, Faridganj, Matlab, Haimchar and Shahrasti.5.2 Lakshmipur District5.2.1 GeographyLakshmipur District with an area of 1455.96 km², is bounded by chandpur district on thenorth, bhola and noakhali districts upazilas on the south, Noakhali district on the east,barisal and Bhola districts and the meghna and on the west. Maximum temperature34.3°C, minimum 14.4°C; annual rainfall 3302 mm. Main rivers are the Meghna, dakatia,Katakhali, Rahmatkhali and Bhulua. Salah Uddin | 032013
  27. 27. 5.2.2 SubdivisionsIt consists of 4 upazilas, 3 municipalities, 30 wards, 55 mahallas, 47 union parishads, 445mouzas and 536 villages. The upazilas are lakshmipur sadar, raipur, ramganj and ramgati.Land use Cultivable land 1 25466 hectares, fallow land 9704 hectares, forest area 9604hectares; single crop 25.85%, double crop 59.03%, triple crop 15.12%.Population 1479371; male 49.21%, female 50.79%; Muslim 95.31%, Hindu 4.66%,Christian 0.01%, Buddhist 0.01% and others 0.01%.5.3 Noakhali DistrictNoakhali is a district in South-eastern Bangladesh. Noakhali District Division: Chittagong Area (km²) 3,600 Total:25,33,394 Population: Male: 48.91% Female: 51.09%5.3.1 GeographyNoakhali District ( part of Chittagong division ) with an area of 3600.99 km², is boundedby Comilla district on the north, the Meghna estuary and the Bay of Bengal on the south,Feni and Chittagong districts on the east, Lakshmipur and Bhola districts on the west.Annual average temperature: maximum 34.3 °C, minimum 14.4 °C; annual rainfall 3302mm. Main rivers are Bamni and meghna. Salah Uddin | 032013
  28. 28. 5.3.2 SubdivisionsNoakhali district, whose earlier name was Bhulua, was established in 1821. It consists ofeight upazilas, 5 municipalities, 45 wards, 90 mahallas, 83 union parishads, 909 mouzasand 978 villages. The upazilas are Noakhali sadar, Subarna Char, Kabirhat, Begumganj,Chatkhil, Companiganj, Hatiya and Senbagh; the municipalities are Begumganj(Chawmuhani), Companiganj (Bashurhat), Noakhali Sadar, Chatkhil, Kabirhat (Sadar). Salah Uddin | 032013
  29. 29. 6. Flood Reports of the study areas (non-flood period & floodperiod)6.1 Non-flood period Report N O R T H Figure 8: Image of Non-flood periodLegend Water Vegetation1 soil vegetation2 Salah Uddin | 032013
  30. 30. The following tables (Table 5, Table 6 & Table 7) shows the informations about Non-flood period of Chandpur, Lakshmipur & Noakhali districts respectively.District Name: ChandpurClass Name Count % HectaresWater Area 376440 18.83 33879.600Land Area 1279565 64.01 115160.850Vegetation 343135 17.17 30882.15Total 1999140 100 179922.600 Table 5 : Information about Non-flood period of Chandpur districtDistrict Name: LakshmipurClass Name Count % HectaresWater Area 442846 26.28 39856.140Land Area 855054 50.74 76954.860Vegetation 387347 22.98 34861.23Total 1685247 100 151672.230 Table 6 : Information about Non-flood period of Lakshmipur districtDistrict Name: NoakhaliClass Name Count % HectaresWater Area 2261076 48.88 203496.840Land Area 1814516 39.22 163306.440Vegetation 550522 11.9 49546.98Total 4626114 100 416350.260 Table 7 : Information about Non-flood period of Noakhali district Salah Uddin | 032013
  31. 31. 6.2 Flood Report, July 7, 1998The following tables (Table 8, Table 9 & Table 10) shows the informations about floodperiod of July 7, 1998 of Chandpur, Lakshmipur & Noakhali districts respectively.District Name: Chandpur Class Name Count % HectaresWater Area 824267 41.23 74184.030Land Area 1174873 58.77 105738.570Total 1999140 100 179922.600 Table 8 : Information about flood period of July 7, 1998 of Chandpur districtDistrict Name: Lakshmipur Class Name Count % HectaresWater Area 532406 43.82 47916.540Land Area 682699 56.18 61442.910Total 1215105 100 109359.450 Table 9 : Information about flood period of July 7, 1998 of Lakshmipur districtDistrict Name: Noakhali Class Name Count % HectaresWater Area 508638 39.87 45777.420Land Area 767046 60.13 69034.140Total 1275684 100 114811.560 Table 10 : Information about flood period of July 7, 1998 of Noakhali district Salah Uddin | 032013
  32. 32. 6.3 Flood Report, September 10, 1998 Legend N O R Water T H Soil Figure 9 : Image of flood period September 10, 1998 Salah Uddin | 032013
  33. 33. The following tables (Table11, Table 12 & Table 13) shows the informations about floodperiod of September 10, 1998 of Chandpur, Lakshmipur & Noakhali districtsrespectively.District Name: Chandpur Class Name Count % HectaresWater Area 1105353 44.79 80580.234Land Area 1362728 55.21 99342.871Total 2468081 100 179923.105 Table 11 : Information about flood period of September 10, 1998 of Chandpur districtDistrict Name: Lakshmipur Class Name Count % HectaresWater Area 1061685 51.03 77396.837Land Area 1018879 48.97 74276.279Total 2080564 100 151673.116Table 12 : Information about flood period of September 10, 1998 of Lakshmipur districtDistrict Name: Noakhali Class Name Count % HectaresWater Area 3353664 58.72 244482.106Land Area 2357504 41.28 171862.042Total 5711168 100 416344.147 Table 13 : Information about flood period of September 10, 1998 of Noakhali district Salah Uddin | 032013
  34. 34. 6.4 Flood Report, August 25, 1998The following tables (Table14, Table 15 & Table 16) shows the informations about floodperiod of September 10, 1998 of Chandpur, Lakshmipur & Noakhali districtsrespectively.District Name: Chandpur Class Name Count % HectaresWater Area 1321570 66.11 118941.300Land Area 677570 33.89 60981.300Total 1999140 100 179922.600 Table 14 : Information about flood period of August 25, 1998 of Chandpur districtDistrict Name: Lakshmipur Class Name Count % HectaresWater Area 1293941 76.78 116454.690Land Area 391306 23.22 35217.540Total 1685247 100 151672.230 Table 15 : Information about flood period of August 25, 1998 of Lakshmipur districtDistrict Name: Noakhali Class Name Count % HectaresWater Area 3768664 81.47 339179.760Land Area 857450 18.53 77170.500Total 4626114 100 416350.260 Table 16 : Information about flood period of August 25, 1998 of Noakhali district Salah Uddin | 032013
  35. 35. 7. Result & DiscissionsThe first phase of the study was carried out with objectives such as, monitoring floods asaccurately as possibleFor this study, we use the radar images of July 7, August 25, September 10 and a non-flooded period, 1998. The full extent of the images, that covered almost the whole ofBangladesh, was used to map open water flooding in successive image dates.From the Statistics of Bangladesh Flood and fig. 4, fig. 5 & fig. 6 (Bangladesh RiverSystem), we can see that the 1998 flood in Bangladesh has been characterized as one ofthe most catastrophic deluges on record. Water levels in all the rivers exceeded dangerlevels with local rainfall occurring in catchments of small rivers. The consequent bankoverflow and drainage congestion resulted in a flood that extended over most of thecountry for months causing heavy loss of human lives, and damage to crops andinfrastructures.My study areas are Chandpur, Lakshmipur & Noakhali districts of Bangladesh. Thesethree districts are situated on the bank of the river Meghna. Their land type are MediumLow Land. That’s why from the non-flood period data, we can see their water areas are18.83%, 26.28%, and 48.88% respectively. And Flood Repor July 7, 1998 the water areaswere 41.23%, 43.82% and 39.87% respectively.But these three districts has been characterized as one of the most catastrophic deluges onrecord in August , 1998. Because (fig. 6, Bangladesh River System) water level of riverMeghna at Bhairab Bazar in August exceedded danger level with local rainfall. Thenwater level become little low in september but again it goes high in November.Theconsequent bank overflow such a level resulted catastrophic flood. The flood effectedareas was 66.11%, 76.78% and 81.47% respectively in August 25, 1998 and 44.79%,51.03% and 58.72 % respectively in September 10, 1998. Salah Uddin | 032013
  36. 36. 7.1 Vulnerability of FloodComparision between non-flood period & Flood period dataIn non-flooded period the water areas of my study areas are like the following table 17and Figure 6.10 shows the daily water discharge in m3/sec of the river Meghna at theBhairab Bazar measuring station near the present study areas. The water discharge wasless than 2,000 m3/sec in April to May 1998. District Name % of Total Area HectaresChandpur 18.83 33879.600Lakshmipur 26.28 39856.140Noakhali 48.88 203496.840 Table 17 : water areas of non-flood period of the study areas25th August 1998, it was one of the devastating flood in our country. Water level of therivers begins to rise steadily at the onset of the moonsoon and reach tjeir paek level inJuly, August and September. Flash floods occur in the northeastern and northern areas ofthe country at any time during the monsoon. Wide spread overland flooding becomesevere and devastating when the peak of the Ganges, the Brahmaputra and the Meghnasyschronize and remain at high stage for longer period. Salah Uddin | 032013
  37. 37. Fig: 6 shows the daily water discharge in m3/sec of the river Meghna at the BhairabBazar measuring station near the present study areas. The water discharge attained a veryhigh value of about 12,000 m3/sec in August 1998. That’s why it was the mostdevastating flood of the recorded history.The water areas of flood period in 25th August 1998 are flows- District Name % of Total Area HectaresChandpur 66.11 118941.300Lakshmipur 76.78 116454.690Noakhali 81.47 339179.760 Table 18 : water areas of flood period in 25th August, 1998 of the study areas7.2 Flood affected areas calculation in 25th August 1998So, if we subtract the data from flood period 25th August 1998 to non-flood period andflood, we can easily find out the flood-affected areas in 25th August 1998.The flowing table shows the flood-affected areas in 25th August 1998 District Name % of affected Area HectaresChandpur (66.11-18.83)= 47.28 (118941.300-33879.600)=85061.7Lakshmipur (76.78-26.28)=50.5 (116454.690-39856.140)=76598.55Noakhali (81.47-48.88)=32.59 (339179.760-203496.840)=135682.92 Table 19 : flood-affected areas in 25th August, 1998 of the study areasThe application of remote sensing in flood monitoring is a tested technology and issuitable for flood monitoring. Salah Uddin | 032013
  38. 38. 8. ConclusionThis thesis work has been carried out for the partial fulfillment of the requirements forBachelor of Sciences degree in Information Technology. Chandpur, Lakshmipur &Noakhali districts have been taken up as the study areas for understand the floodphenomenon in Bangladesh.Proper management and monitoring of natural resources is an important pre-condition forsustainable development of an area. Management through appropriate land evaluationsupported by efficient monitoring system can yield maximum benefit. The urgency of apotential tool accomplishing such objectives has directed to carry out the present study.The study has been supplemented by a number of GPS-based surveys to verify the resultof digital analysis and classification. Through the limited number of ground observationan interpreted key to classify the study have been evolved and the GPS-based referencepoint used to correct the spatial mismatching.A comprehensive database has been generated in GIS platform containing informationvarious flood-periods information, comparison between non-flood period & flood-periodand its characteristics and reasons.Monitoring the flood-period for the study areas have been studied with the aid ofRADARSAT data in associated with GMS, Landsat TM data and hydrological data.The study indicates that remote sensing technology integrated with GIS is very effectivefor land evaluation. But, at the same time availability of real time data is a majorconstrains in this regard. In some cases real time data is supplemented by other ancillarydata but it increases the possibility of degradation in respect of accuracy. GIS have widerange of scope for dealing with spatial and non-spatial data. As the data extracted fromdifferent sources, the question of accuracy is so common. But, through the manipulationof problematic attributed along with the data GIS support to maximize as high aspossible. In the present study application of GIS is remarkable found as effective,sophisticated and useful tool. Salah Uddin | 032013
  39. 39. In the following a number of specific remark has been made: The study areas (Chandpur, Lakshmipur & Noakhali) are the flood-affected areas. Because of the mid low lands & water level of Meghna river become high in the summer season. In 25th August 1998, the food-affected areas of Chadpur, Lakshmipur & Noakhali districts were 47.28% (85061.7 hec), 50.5% (76598.55 hec) & 32.59 (135682.92 hec) as respectively.After analysis & monitoring the Flood Phenomenon in Bangladesh ensuing suggestionshave been made: Satellite Remote Sensing and GIS techniques are established as most powerful tools to study the flood monitoring system. From these techniques we can easily compare flooded and non-flooded areas favorably with ground information collected simultaneously to the radar data. We can use multi-temporal data for watching changes in flood extent The satellite imagery provides an understanding of complex land use practices, which vary greatly between the dry season and the monsoon flood period. Salah Uddin | 032013
  40. 40. 9. References Information for Flood Management in Bangladesh: Main Report, Riverside Technologies Inc. and Environment and GIS Support Project for Water Sector, 2000 Summary Report Based on Studies carried out under the Flood Action Plan, FPCO, 1995 S. M. Humayun Kabir- “Integrated Use of Satellite Remote Sensing and GIS in Optimal Land Use Planning for Agricultural Development” 2003 Water and Power Development Master Plan, EPWAPDA, 1964 National Water Plan, MPO, 1986 A.N.H. Akhter Hossain- “BANGLADESH: FLOOD MANAGEMENT” 2003 Water Sector Study Report, IBRD, 1972 Flood and Water Management Strategy, FPCO, 1996 Chandpur District – From Wikipedia, the free encyclopedia. Lakshmipur District – From Wikipedia, the free encyclopedia. Noakhali District – From Wikipedia, the free encyclopedia. Salah Uddin | 032013
  41. 41. 10. AppendixList of FiguresFig. 1: Location map of BangladeshFig. 2: Hydrological zones of BangladeshFig. 3: River system of BangladeshFig 4: 10-daily Discharge at Hardinge Bridge on the GangesFig 5: 10-daily Discharge at Bahadurabad on BrahmaputraFig 6: 10-daily Discharge at Bhairab Bazar on MeghnaFig 7: Map of Study AreasFig 8: Image of Non-flood periodFig 9 : Image of flood period September 10, 1998List of TablesTable 1: Important flood events in BangladeshTable 2: Land Types information of BangladeshTable 3: Statistics of Flood events in BangladeshTable 4: Basic sensor characteristics of Landsat TMTable 5 : Information about Non-flood period of Chandpur districtTable 6 : Information about Non-flood period of Lakshmipur districtTable 7 : Information about Non-flood period of Noakhali districtTable 8 : Information about flood period of July 7, 1998 of Chandpur districtTable 9 : Information about flood period of July 7, 1998 of Lakshmipur districtTable 10 : Information about flood period of July 7, 1998 of Noakhali districtTable 11 : Information about flood period of September 10, 1998 of Chandpur districtTable 12 : Information about flood period of September 10, 1998 of Lakshmipur districtTable 13 : Information about flood period of September 10, 1998 of Noakhali districtTable 14 : Information about flood period of August 25, 1998 of Chandpur district Salah Uddin | 032013
  42. 42. Table 15 : Information about flood period of August 25, 1998 of Lakshmipur districtTable 16 : Information about flood period of August 25, 1998 of Noakhali districtTable 17 : water areas of non-flood period of the study areasTable 18 : water areas of flood period in 25th August, 1998 of the study areasTable 19 : flood-affected areas in 25th August, 1998 of the study areas Salah Uddin | 032013

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