Evaluation of the Performance of Satellite Precipitation Products over Africa Item Type text; Electronic Thesis Authors Merino, Manuel Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 08/10/2021 04:09:29 Link to Item http://hdl.handle.net/10150/293730 1 EVALUATION OF THE PERFORMANCE OF SATELLITE PRECIPITATION PRODUCTS OVER AFRICA by Manuel Merino _________________________________________________ A Thesis Submitted to the Faculty of the DEPARTMENT OF HYDROLOGY AND WATER RESOURCES In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE WITH A MAJOR IN HYDROLOGY In the Graduate College THE UNIVERSITY OF ARIZONA 2013 2 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that an accurate acknowledgement of the source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: Manuel Merino APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: April, 26th, 2013 Dr. Juan B. Valdes Date Professor of Hydrology 3 ACKNOWLEDGEMENTS I want to give my fullest acknowledgments to my committee members Juan B. Valdes, Aleix Serrat-Capdevila, and Hoshin Gupta for their very valuable ideas, orientation, suggestions, and corrections. A warm thanks to Eleonora Demaría and Matej Durcik for their invaluable help in the progress of my thesis, to Dr. W. James Shuttleworth y Dr. Gustavo Goncalves for their recommendations and references, and Dr. Larry Winter for his help and support during this Master. My thanks also, for the institutions that generously made this four semesters of study feasible: GeoAguas Consultores, CONICYT-Chile through the BecasChile fellowship program, the Department of Hydrology and Water Resources of the University of Arizona, the Galileo Circle, and their members Charles and Elena d’Autremont. In the end in this statement, but not in my heart, I want to thank my family here and in Chile, especially Evelyn for their support, patience and help. TABLE OF CONTENTS LIST OF FIGURES ................................................................................................ 8 LIST OF TABLES ................................................................................................ 13 ABSTRACT .......................................................................................................... 15 1 INTRODUCTION .......................................................................................... 16 2 LITERATURE REVIEW ............................................................................... 18 2.1 Rainfall Measurement ............................................................................. 18 2.2 Satellite Precipitation Products estimation strategies ............................. 19 2.2.1 VIS/IR based estimates ..................................................................... 19 2.2.2 MW based estimates.......................................................................... 21 2.2.3 Mixed estimates................................................................................. 23 2.3 Errors of Satellite Precipitation Products ................................................ 28 2.3.1 Evaluation of SPP over Africa .......................................................... 29 2.3.2 Performance and error metrics used for SPP .................................... 31 2.4 Bias correction and error reduction for SPP ........................................... 34 2.4.1 Methods used in this study ................................................................ 36 3 METHODOLOGY ......................................................................................... 39 3.1 Precipitation data used ............................................................................ 39 5 TABLE OF CONTENTS - Continued 3.2 Analysis of the different SPP .................................................................. 42 3.2.1 All Africa........................................................................................... 42 3.2.2 Latitudinal bands ............................................................................... 42 3.2.3 Koppen Geiger Climatic Classification............................................. 45 3.2.4 Topography ....................................................................................... 46 3.3 Bias correction and error reduction of SPP ............................................. 47 3.4 Error quantification and heteroscedasticity ............................................. 47 3.5 Lumped simulation of streamflow with bias corrected SPPs.................. 49 4 RESULTS AND DISCUSSION ..................................................................... 52 4.1 All Africa ................................................................................................ 52 4.2 Latitudinal bands ..................................................................................... 55 4.2.1 Band A............................................................................................... 56 4.2.2 Band B ............................................................................................... 57 4.2.3 Band C ............................................................................................... 58 4.2.4 Band D............................................................................................... 59 4.2.5 Band E ............................................................................................... 60 4.2.6 Band F ............................................................................................... 61 4.3 Koppen Geiger Climatic zones ............................................................... 62 6 TABLE OF CONTENTS - Continued 4.4 Topographic classification ...................................................................... 65 4.5 Bias corrected data .................................................................................. 66 4.6 Effect of bias correction on errors ........................................................... 71 4.7 Error distributions and heteroscedasticity of errors ................................ 75 4.8 Model averaging ...................................................................................... 78 4.9 Streamflow simulations ........................................................................... 79 4.9.1 Single calibration and simulation period ........................................... 80 4.9.2 Bootstrap method .............................................................................. 82 5 CONCLUSIONS AND FUTURE WORK ..................................................... 83 A. APPENDIX – RAW DATA SCATTERPLOTS FOR LATITUDE BANDS 85 B. APPENDIX – RAW DATA SCATTERPLOTS FOR KOPPEN GEIGER CLIMATIC CLASSIFICATION ZONES ........................................................................ 95 C. APPENDIX – RAW DATA SCATTERPLOTS FOR TOPOGRAPHIC CLASSIFICATION ZONES ............................................................................................ 99 D. APPENDIX - BIAS CORRECTED SCATTERPLOTS FOR LATITUDE BANDS 103 E. APPENDIX – BIAS CORRECTED SCATTERPLOTS FOR CLIMATIC CLASIFFICATION ZONES- ......................................................................................... 112 7 TABLE OF CONTENTS - Continued F. APPENDIX – BIAS CORRECTED SCATTERPLOTS FOR TOPOGRAPHIC CLASSIFICATION ZONES ............................................................. 117 G. APPENDIX – HISTOGRAMS OF ERRORS WITH FITTED GAMMA DISTRIBUTIONS .......................................................................................................... 120 6 REFERENCES ............................................................................................. 123 8 LIST OF FIGURES Figure 2-1: Comparison of monthly rainfall between GPCC and GPI algorithm (Prakash, Mahesh, & Gairola, 2011) ................................................................................................ 20 Figure 2-2: Comparison between TMI estimates, using GPROF, and GPCC rain gauge estimates (Rudolf et al., 1996) .......................................................................................... 23 Figure 2-3: Combined MW precipitation for an arbitrary 3 hour period. Black zones lack of reliable estimates. The different sensors shown are: TMI (white), SSM/I (light gray), AMSR-E (medium gray), and AMSU-B (dark grey) (Huffman et al., 2007) .................. 24 Figure 2-4: PERSIANN system (Gupta, 2013)................................................................. 28 Figure 3-1: The Global Precipitation Climatology Project (Gruber & Levizzani, 2008) . 41 Figure 3-2: Latitudinal bands and soil cover map used for its definition (Source: http://www.swaat.arizona.edu/SenegalRiver/MapsAfrica.html#maps)