Detecting date palm trees health and vegetation greenness change on the eastern coast of the United Arab Emirates using SAVI

Due to shortage of fresh water resources, the vegetation of the eastern region of the United Arab Emirates (UAE) has experienced a series of declines resulting from salinization of groundwater, which is the major source of irrigation. To assess these changes, field measurements combined with Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) based Soil Adjusted Vegetation Index (SAVI) were analysed. TM and ETM+ images from two dates, 1987 and 2000 were acquired to enable the computation of the greenness anomalies for three sites in the eastern region, Fujairah, Kalba and Hatta. The results show an overall increase in agricultural area, associated with a severe decrease in vegetation greenness and health conditions, particularly in the Kalba study area. The SAVI values decreased with increased soil salinity, permitting the identification of salt-affected areas. This remotely sensed data offered valuable information regarding vegetation health conditions, especially when using greenness indices. However, in open canopies, like date palm trees, soil line indices, such as, SAVI are more robust, since they account for the contribution of the soil background. This research suggests, that in order for the date palm trees of this region to stay productive, considerable attention needs to be placed in managing and monitoring soil salinity conditions and progress. Potential areas of further research range from studying the effects of tree spacing and understory crops as immediate and potential solutions to maintain productivity and mitigate the salinity problem.