My first and foremost gratitude is expressed to my promoter, prof. dr. ir. Alfred Stein, who has been a true inspiration throughout my research period. He taught me to think in the most critical and independent ways, and gain confidence in many, if not all aspects of scientific matters. He further adapted to my not advisable "communication frequency" (which means composed of rather long periods of silence), without loosing his patience. It was an honour to work with him.I extend my gratitude to my co-promoter, dr. ir. Wietske Bijker, who has always been professional and friendly throughout my research period in The Netherlands and Rwanda. She will remain a role model for me. Her strong sense of practicality and critical thinking helped me, particularly at times of "brain freezing" events. I will always remember our lunch trips to Intratuin or the ginger pies she was bringing, which were her treats to help me relaxing.I sincerely express my deepest gratitude to dr. ir. Arta Dilo, dr. ir. Ulan Turdukulov, and Siqi Ding, for the inspiration and enthousiam during our collaborative work. Many thanks to the staff of the Earth Observation Science department and various PhD students at ITC for valuable dicussions and feedback; to Bas Restios and Petra Budde for their technical support; to Sjoerd for the cover design; to dr. ir. Rolf de By for the L A T E X thesis template design; to Teresa, Loes and all ITC support departments.To all my friends in the Netherlands and all over the World: you have brought support, laughter, care and love; you have put up with me in many touching ways. I cannot mention names, neither express enough my gratitude. Particular thanks to IPC board members and ITC Run4fun runners with coach Wan Bakx for the memorable time we shared.Many thanks to the Rwandan Meteorological Service for the provision of meteorological data and to local authorities of the disctrict of Bugesera for facilitating the field work. Last but not least, deepest gratitude to dr. Michèle A. Schilling; NUFFIC via the NPT/RWA/071 project and the