PROGRAMA DE DOCTORADO EN FISICA TESIS DOCTORAL: Identifying Desert locust breeding areas by means of Earth Observation in Mauritania Presentada por Diego Gómez Aragón para optar al grado de Doctor por la Universidad de Valladolid Dirigida por: Dra. Julia Sanz Justo Dr. Pablo Salvador González Dr. Carlos Casanova Mateo Valladolid, 2019 Identifying desert locust breeding areas by means of Earth Observation in Mauritania Doctorate programme on Applied Physics “Earth observation, environmental modelling and remote sensing” Diego Gómez Aragón PhD Advisor: Dr. Jose Luis Casanova (UVA, Spain) PhD Director/s: Dra. Julia Sanz Justo, Dr. Pablo Salvador and Dr. Carlos Casanova Mateo (UVA, Spain) “Nothing would be done at all if a man waited till he could do it so well that no one could find fault with it” J. H. Newman Acknowledgements Firstly, I would like to show my sincere gratitude to José Luis Casanova to trust on me and provide a great support during my PhD. Without his recommendations, advices and knowledge, this thesis would not have been possible. I would also like to thank my PhD directors Julia Sanz, Pablo Salvador and Carlos Casanova for their continuous support during this time, for their patience, motivation, and immense knowledge. Their guidance helped me in all the time of research and writing of this thesis. I could not have imagined having better advisors and mentors for my PhD study. I would like to thank to the rest of my fellow lab-mates at LATUV (Miguel and Dani) their support, the stimulating discussions about programming, encouragement and good advices during my research, what has permitted to enrich this work from various perspectives. Last but not least; I would like to thank my family: my parents and sister for supporting me to get to the point where I am today, and to my partner and friends to encourage me to keep on until this desired goal. TABLE OF CONTENTS Abstract ................................................................................... 1 Resumen ................................................................................... 3 List of abbreviations ................................................................... 5 Chapter 1.- INTRODUCTION ........................................................... 7 1.1. Research hypotheses ....................................................................................... 7 1.2. Antecedents and research interest ................................................................... 7 1.2.1. Historical background of desert locust .......................................................................... 7 1.2.2. Remote sensing .............................................................................................................. 8 1.2.3. Artificial Intelligence applied on Remote sensing data ................................................ 12 1.2.4. Species Distribution Models ......................................................................................... 15 1.3. Description of the study area ......................................................................... 19 1.3.1. Location ........................................................................................................................ 19 1.3.2. Topography and drainage ............................................................................................ 20 1.3.3. Climatic conditions ....................................................................................................... 23 1.3.4. Geology and geomorphology ....................................................................................... 26 1.3.5. Land cover and soil type............................................................................................... 27 1.3.6. Vegetation and animal life ........................................................................................... 28 1.4. The biology of desert locust ........................................................................... 29 1.4.1. Locust Phases ............................................................................................................... 32 1.4.2. Life cycle ....................................................................................................................... 33 1.4.3. Environmental circumstances of the habitat ............................................................... 34 1.4.4. Migration and seasonal distribution ............................................................................ 35 1.4.5. Important terms ........................................................................................................... 36 1.5. Thesis structure, specific goals and objectives ................................................ 37 Chapter 2. Identification of potential wadis using SWAT hydrological model ............................................................................................. 39 2.1 Introduction ................................................................................................... 39 2.2. Materials and Methods .................................................................................. 42 2.2.1. Input data ..................................................................................................................... 42 2.2.2. Methods ....................................................................................................................... 47 2.3. Results and discussion ................................................................................... 55 2.3.1. Model set up ................................................................................................................ 55 2.3.2. Sensitive parameters .................................................................................................... 58 2.3.3. Calibration and validation ............................................................................................ 60 2.3.4. Distances between desert locust and PRoW ............................................................... 64 2.4. Conclusion ..................................................................................................... 66 Chapter 3. Soil moisture analysis to locate breeding areas using machine learning techniques .................................................................... 69 3.1. Introduction .................................................................................................. 69 3.1.1. Species occurrence data .............................................................................................. 70 3.1.2 Data cleaning ................................................................................................................. 70 3.1.3. Sampling bias ............................................................................................................... 70 3.1.4. Absence, pseudo-absence or background points ........................................................ 71 3.1.5. Extraction and preparation of environmental data ..................................................... 71 3.2. Materials and Methods .................................................................................. 72 3.2.1 Survey data.................................................................................................................... 72 3.2.2. Satellite data ................................................................................................................ 73 3.2.3. Methods ....................................................................................................................... 74 3.3. Results .......................................................................................................... 86 3.4. Discussion ..................................................................................................... 92 3.5. Conclusions ................................................................................................... 94 Chapter 4. Multivariate ensemble model to detect desert locust ........... 97 4.1. Introduction .................................................................................................. 97 4.2. Materials and methods .................................................................................. 98 4.2.1. Field data and pseudo-absences .................................................................................. 98 4.2.2. Environmental variables............................................................................................. 100 4.2.3. Methods ..................................................................................................................... 103 4.3. Results ........................................................................................................ 113 4.3.1. Model evaluation ....................................................................................................... 113 4.3.2. Variable importance ................................................................................................... 115 4.3.3. Response curves and living thresholds ...................................................................... 117 4.4 Discussion .................................................................................................... 120 4.5 Conclusion .................................................................................................... 123 Chapter 5. General discussion and conclusions ................................ 125 Chapter 6. References ..............................................................