A D D I S A B A B A U N I V E R S I T Y SCHOOL OF GRADUATE STUDIES E A RT H S C I E N C E D E PA RT M E N T THERMAL MAPPING AND LINEAMENT ANALYSIS OF ABIYATA AND LANGANO LAKES REGION IN CENTERAL ETHIOPIAN RIFT SYSTEM BY BINYAM TESFAW HAILU M A R C H 2 0 0 7 TH ERMAL MAPPI NG AND LI NEAM ENT A N A LYS I S O F A B I YATA A N D L A N G A N O L A K E S R E G I O N I N C E N T E R A L E T H I O P I A N R I F T S Y S T E M A THESIS SUBMITTED TO THE SCHOOL OF GRADUTE STUDIES ADDIS ABABA UNIVERSITY IN PA RT IAL FULFILMENT OF THE REQUIR ME NTS FOR THE MASTERS OF SCIENCE DEGREE IN REMOTE SENSING AND GIS BY BINYAM TESFAW HAILU M A R C H 2 0 0 7 ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES THERMAL MAPPING AND LINEAMENT ANALYSIS OF ABIYATA AND LANGANO LAKES REGION IN CENTERAL ETHIOPIAN RIFT SYSTEM By Binyam Tesfaw Hailu Department of Earth Sciences Science Faculty APPROVED BY BOARD OF EXAMINERS Dr. Balemwal Atnafu (PhD.) ______________________________ U U Chairman Dr. Dagnachew Legesse (PhD) ______________________________ U U Advisor. Dr. Bekele Abebe (PhD) ______________________________ U U Co-Advisor. Dr. Syed Ali (PhD) ______________________________ U U Internal Examiner. Dr. Abera Alemu (PhD) _______________________________ U U Internal Examiner. Declaration, I, the undersigned declare that this thesis is my original work, has not been presented for a degree in any other university and that all sources of material for thesis have been duly acknowledged. Binyam Tesfaw School of Graduate Studies March 2007. Acknowledgement I would like to thank Dr. Dagnachew Legesse and Dr. Bekele Abebe in a special way that advised and shared their knowledge, critical reading of the manuscript and their helpful comments give the present form of this thesis. In addition I thank him Mr. Haili Jia , who gave the Visual Basic Scripts for this study , from Department of Earth Sciences, University of the Western Cape, South Africa. I luckily recognize the Ethiopian Geological Survey, Hydrothermal department and its librarian for their wholehearted and kind collaboration in delivering me the most valuable data even without a brief time of delay, the Awasa T.V.E.T. College for allowing me to pursue my postgraduate studies. I also would like to forward my heart felt thanks to all the member of MaWari (Management of water resources in the Rift Valley) especially Dr. Tamiru Alemayehu and Dr. Dagnachew Legesse who arranged the field work and gave me materials for fulfilling this thesis. I would like to thank all friends whose name is not mentioned, for their encouragement and material support either through e-mail or in person. i Table of Contents Acknowledgement ........................................................................i Abbreviations ..............................................................................ii List of Figures............................................................................. vi List of Tables.............................................................................viii List of Appendix........................................................................viii Abstract....................................................................................... x CHAPTER ONE General Introduction....................................................................1 1.1. Back Ground.............................................................................................1 1.2. Objectives.................................................................................................1 1.3. Specific Objectives....................................................................................2 1.4.Description of the study area.....................................................................3 1.5. Theoretical Background............................................................................6 1.5.1.Remote sensing.................................................................................6 1.5.2. Thermal Remote sensing..................................................................9 1.5.2.1. The Plank's Law.....................................................................10 1.5.2.2. Wien’s Law.............................................................................11 1.5.2.3. Stefan Boltzman Law.............................................................12 1.5.2.4. Energy emitted by grey and real bodies.................................13 1.6. Literature Review....................................................................................14 1.7. Materials and Methodology.....................................................................18 CHAPTER TWO Data Analysis............................................................................. 22 2.1. Image processing for thermal mapping...................................................22 2.1.1. Conversion of DN Values to Radiance...........................................23 2.1.2. Conversion of radiance to at Satellite temperature.........................25 2.1.3. Estimation of emmisivies................................................................26 2.1.4. Land Surface temperature..............................................................27 2.1.5. Surface Kinetic Temperature..........................................................27 2.2. Lineament Analysis.................................................................................28 iv 2.2.1. Preparation of Lineament map.......................................................28 2.2.2. Development of VBA scripts for lineament Analysis...........................32 CHAPTER THREE Results and Discussion.................................................................................34 3.1. Thermal mapping....................................................................................34 3.1.1. Radiance........................................................................................34 3.1.2. At Satellite temperature..................................................................35 3.1.3. Emmisivity Corrected at_satellite temperature...............................37 3.1.4. Surface Kinetic Temperature..........................................................40 3.2. Lineament Analysis.................................................................................43 3.1.1. Preparation of basic Lineament map..............................................43 3.1.2. Lineament Length density ..............................................................47 3.1.3. Lineament Number density.............................................................48 3.1.4. Lineament Orientation....................................................................51 3.1.5. Lineaments with Ground water occurrence....................................53 3.2. Comparison of Lineaments and Thermal manifestation..........................58 3.3. Thermal map with field observation........................................................59 CHAPTER FOUR Conclusions and Recommendations.......................................................62 References................................................................................. 65 Appendix ...................................................................................69 v List of Figures Figure 1: Location map of the study area. ..............................................................4 Figure 2: Topographic map of the study area derived from SRTM......................... 5 Figure 3: The Electromagnetic Spectrum after Thomas M. Lillesand and Ralph W.Kiefer, 1994........................................................................................6 Figure 4: Spectral exitance distributions for blackbodies at 6000, 4000, 2000, and 1000 K.............................................................................................10 Figure 5: General approach and Methodology used for estimating surface kinetic temperature and emmisivity using LANDSAT 7......................20 Figure 6: General methodology and materials used structure for this thesis work ................................................................................................................21 Figure 7: Lineament map of the Langano and Abijata lakes region digitized from the structural map of the central Ethiopian rift...................................30 Figure 8: The grid that is computed with 5km width for calculating the lineament density...................................................................................31 Figure 9-a: Radiance and histogram of thermal band high gain image...............34 Figure 9-b: Radiance and histogram of thermal band low gain image.................35 Figure 10-a: At satellite temperature and its histogram for thermal band 6 high gain........................................................................................................36 Figure 10-b: At satellite temperature and its histogram for thermal band 6 low gain........................................................................................................36 Figure 11: Normalized Difference Vegetative Index for the LANDSAT 7 image....37 Figure 12: Graph of the emmisivity for LANDSAT 7 ETM+..................................38 Figure 13-a: Emmisivity corrected at satellite temperature and its histogram for LANDSAT 7 band6H.............................................................................39 Figure 13-b: Emmisivity corrected at satellite temperature and its histogram for LANDSAT 7 band6L..............................................................................39 Figure 14-a: Surface kinetic temperature and its histogram for LANDSAT 7 band6H..................................................................................................40 Figure 14-b: Surface Kinetic temperature and its histogram for LANDSAT 7 band6L....................................................................................................41 vi Figure 15: The colored combined image of kinetic surface temperature...............41 Figure 16: the filtered images using spatial filtering A) using North-South Kernel and the filtered image B) East-West Kernel and its result C)NorthEast-SouthWest Kernel and filtered output D)NorthWest- SouthEast Kernel and its result ............................................................45 Figure 17: Extracted lineaments from the four directional filtered images with a scale of 1:100000...................................................................................46 Figure 18: Lineament length density map constructed using the result of script (Appendix 2)..........................................................................................48 Figure 19: Lineament Number density map constructed using the result of script (Appendix 3)................................................................................49 Figure 20: Lineament Orientation map and rose diagram constructed using the result of script (Appendix 3).................................................................52 Figure 21: Lineament density map is overlaid with the ground water table contour. .................................................................................................54 Figure 22: Lineament orientation map is overlaid with the ground water table contour. .................................................................................................54 Figure 23: Map of Lineaments in the study area is overlaid with the ground water table contour. .............................................................................. 55 Figure 24: well distribution and their perspective subgroup ................................57 Figure 25: Collins bar diagram using subgroup mean defined by HCA................57 Figure 26: Relationship of lineaments with thermal map ...................................58 Figure 27: Additional lineaments extracted from the thermal map with the scale of 1:100000. ..........................................................................................59 Figure 28: Thermally altered areas and hot springs observed during field work.60 Figure 29: Thermally altered rocks which affected by the hot spring which discharged from Aluto Mountain and eastern High lands...................60 Figure 30: comparison of the thermal map obtained using satellite images with the field observed thermally high area ..................................................61 vii List of Tables Table 1: Landsat ETM+ characteristics.....................................................................7 Table 2: Principal applications of the Landsat Thematic Mapper bands (from Thomas M. Lillesand and Ralph W.Kiefer, 1994.).....................................................8 Table 3: description if the image used for the thermal mapping............................18 Table 4: Spectral Considerations of LANDSAT 7 ETM+........................................19 Table 5: LANDSAT7 ETM+ Spectral Radiance Range (USGS) .............................24 Table 6: ETM+ Thermal Band Calibration Constants (USGS)..............................25 Table 7: High pass directional filtering kernels used for extracting of additional lineaments in the study area with a scale of 1:100000.........................29 Table 8: Table structure and an example of output file produced by “CalculateFractureDensity_LEN2” and “CalculateFractureDensity_num” scripts............................................. 47 Table 9: table structure and an example of output file produced by “CalculateKForPolyline” script..............................................................51 Table 10: Mean values (unit in meq/l) for groups and subgroups derived from Hierarchical cluster analysis (HCA) (Shimelis, 2006) TDS is in mg/l 46 ...........................................................................................56 List of Appendix Appendix 1: Visual basic Script for the lineament orientation analysis and mapping.................................................................................................69 Appendix 2: Visual basic Script for the lineament length density analysis and mapping..................................................................................................71 Appendix 3: Visual basic Script for the lineament number density analysis and mapping................................................................................................. 74 Appendix 4: ground water sample data and their location from different well data in the study area (Source: Shimelis 2006)...................................78 Appendix 5: Scripts that are used for the thermal mapping in ERDAS IMAGINE 8.6 software...........................................................................................80 viii