Regional vegetation water effects on satellite soil moisture estimations for West Africa

Soil moisture information is a vital parameter for water resources planning and food production. In particular for West Africa, where income largely depends on rainfed agriculture, reliable information on available soil water is required for modeling and prediction. Over large areas and, specifically, for data scarce regions, satellite soil moisture estimates are required to obtain reliable information on available soil water. This necessity for satellite-based soil moisture data has already resulted in recent and upcoming satellite launches. Although satellite-based soil moisture estimates have been globally available since the early 1990s, the satellite signal used to derive soil moisture estimates, has yet to be fully understood. In this thesis the interrelation between vegetation water and satellitebased soil moisture estimates is investigated for West Africa. Based on observations and a series of regional models the link between vegetation and satellite signal was hypothesized and tested. New methodologies for ground observations of soil moisture and vegetation water were developed, which provide the means to design experiments for calibration and validation of upcoming soil moisture satellites.