Development of a downscaling scheme for a coarse scale soil water estimation method [Elektronische Ressource] : case study ; Great Letaba River in South Africa / von Cornelia Scheffler

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Informations

• Publié par: friedrich-schiller-universitat_jena
• Publié le: 01 janvier 2008
• Nombre de lectures: 33
• Langue: English
• Poids de l'ouvrage: 12 Mo

Extrait

Development of a Downscaling Scheme for a Coarse
Scale Soil Water Estimation Method
Case Study -- Great Letaba River in South Africa







Dissertation
zur Erlangung des akademischen Grades doctor rerum naturalium
(Dr. rer.nat.)











vorgelegt dem Rat der Chemisch-Geowissenschaftlichen Fakultät der
Friedrich-Schiller-Universität Jena

von Diplom-Geographin Cornelia Scheffler
geboren am 20. August 1978 in Karl-Marx-Stadt (jetzt Chemnitz)































1. Gutachter: Prof. Dr. rer. nat. Wolfgang-Albert Flügel, Jena
2. Gutachter: Univ. Prof. Dr. techn. Wolfgang Wagner, Wien
Tag der öffentlichen Verteidigung: 02.07.2008


ACKNOWLEDGMENT
Working on this dissertation these last few years has been a challenge,
combining achievements and setbacks with joy and sometimes with tears.
Without the support, guidance and patience of the following people this work
would not have been possible.
Special thanks go to Prof. Dr. Wolfgang-Albert Flügel who gave me the
opportunity to write this dissertation in Jena and for his guidance, support and
advice over the last years. I am also grateful to Prof. Dr. Wolfgang Wagner who
supported this work. The discussions with him lead to the ideas that are
presented in this work.
The discussions with Dr. Peter Krause helped me to work through the
technical as well as some challenging argumentative problems with my study.
His constructive criticism helped me to focus my ideas and to describe them
more clearly. I am also thankful to him for reading the dissertation draft within
a short time period.
I am very grateful to all my colleagues of the Department for
Geoinformatics, Hydrology and Modelling, in particular, Dr. Jörg Helmschrot,
Dr. Sven Kralisch, Dr. Manfred Fink, Björn Pfennig, and Daniel Varga who have
given their time to discuss pieces of my work with me and who have also
offered valuable advice. Special thanks also go to Rainer Hoffmann, the system
administrator, who helped with any occurring technical problem.
I am grateful indebted to my friend and colleague Antje Vogel for
proofreading and her constructive comments to improve this dissertation.
Thanks to Markus Reinhold, Evelin Matejka, Cornelia Barth and Timothy Steele
for proof-reading this dissertation.
Thanks to all agencies and institutes providing data for this study: to the
Institute for Photogrammetry and Remote Sensing (IPF) at the Technical
University of Vienna, to the South Africa Weather Service, in particular to
Tracey Gill, to the Council for Scientific and Industrial Research (CSIR) and the
Agricultural Research Council (ARC) for providing the land-cover data, to the
ACKNOWLEDGEMENT
School of Bioresources Engineering and Environmental Hydrology in
Pietermaritzburg, to the Department of Water Affairs and Forestry for
providing the data on geology. Special thanks go to the people with whom I
had such a great time during the field trip in South Africa: Ralda de Wet, Danie
Viljoen, the Family Lorentz and Susann Carter.
Many thanks for financial support from the Marianne und Dr. Fritz
Walter Fischer-Stiftung, whose support made this research possible.
For their continuous and encouraging support, I want to thank all my
friends -- in particular, Lydia Franke, Kathleen Neumann, Daniela Knorr,
Katrin Geiseler and Cornelia Koch.
Special thanks go to my parents and to my brother for their endless
support and the trust in me.
I am especially indebted to my partner Hisham Zerriffi who believed in
me and who encouraged me to persist whenever I lost my faith in finishing this
work. It is to him that I dedicate this work.


CONTENT
LISTS OF FIGURES ................................................................................................................. V
LIST OF TABLES .................................................................................................................. VII
ABBREVIATIONS ...................................................................................................................IX
LIST OF PARAMETERS .....................................................................................................XIII
ABSTRACT............................................................................................................................. XV
KURZFASSUNG.................................................................................................................. XVII
CHAPTER 1 INTRODUCTION ............................................................................................... 1
CHAPTER 2 RESEARCH REVIEW ....................................................................................... 5
2.1 SOIL MOISTURE IN THE HYDROLOGICAL CYCLE ............................................................ 6
2.1.1 DEFINITION OF SOIL MOISTURE........................................................................................ 7
2.1.2 CALCULATION OF SOIL MOISTURE ................................................................................... 9
2.2 ESTIMATION OF THE SOIL WATER CONTENT AND ITS MONITORING .......................... 10
2.2.1 ESTIMATION OF THE SOIL WATER CONTENT USING REMOTE SENSING TECHNIQUES.... 10
2.2.1.1 Microwave Techniques for Soil Water Retrieval ........................................................ 11
2.2.1.2 Fundamentals of Active Microwave Remote Sensing................................................. 13
2.2.1.3 The ERS Macro-Scale Soil Water Estimates............................................................... 16
2.2.2 SOIL MOISTURE GENERATION IN LAND SURFACE MODELING....................................... 21
2.2.2.1 Classification of Models .............................................................................................. 21
2.2.2.2 Determination of Soil Moisture Using Land Surface Modeling.................................. 23
2.3 ON TEMPORAL AND SPATIAL SCALING OF SOIL MOISTURE......................................... 25
I CONTENT
2.3.1 SCALE DEPENDENT SPATIAL AND TEMPORAL DISTRIBUTION OF SOIL MOISTURE
VARIABILITY ............................................................................................................................... 27
2.3.2 THE UP- AND DOWNSCALING PROCESS.......................................................................... 29
2.3.2.1 Upscaling methods....................................................................................................... 30
2.3.2.2 Downscaling Methods ................................................................................................. 32
2.4 RESEARCH NEEDS ............................................................................................................ 33
CHAPTER 3 SCIENTIFIC OBJECTIVES AND METHODICAL APPROACH ............. 35
3.1 STEP I: HYDROLOGICAL SYSTEM ANALYSIS AND DELINEATION OF HYDROLOGICAL
RESPONSE UNITS........................................................................................................................ 37
3.1.1 HYDROLOGICAL SYSTEM ANALYSIS .............................................................................. 37
3.1.1.1 Data Analysis of Hydro-Meteorological Time Series.................................................. 38
3.1.1.2 Spatial Data Modeling ................................................................................................. 39
3.1.2 DELINEATION OF HYDROLOGICAL RESPONSE UNITS ..................................................... 40
3.2 STEP II: RAINFALL-RUNOFF MODELING WITH J2000................................................... 42
3.2.1 MODULAR DESIGN OF J2000........................................................................................... 43
3.2.2 INPUT DATA PREPARATION ............................................................................................ 46
3.2.3 MODEL PARAMETERIZATION AND CALIBRATION........................................................... 47
3.2.3.1 Automatic Parameter Estimation using Sensitivity Analysis....................................... 48
3.2.3.2 Prediction of Model Uncertainty ................................................................................. 50
3.3 STEP III: ANALYSIS OF THE MACRO-SCALE SOIL WATER ESTIMATES WITH THE
SIMULATED SOIL WATER TIME SERIES................................................................................... 51
3.3.1 RETRIEVING THE CATCHMENT AREA COVERED BY ONE ERS-SCATTEROMETER
FOOTPRINT .................................................................................................................................. 51
3.3.2 DELINEATION OF THE HRU-SOIL WATER INDEX (SWI ) ........................................... 51 HRU
3.3.3 PROCEDURES FOR EVALUATION OF THE TIME SERIES AT FOOTPRINT SCALE................ 53
3.3.3.1 Decomposition of Time Series..................................................................................... 53
3.3.3.2 Agreement Criteria....................................................................................................... 54