Monitoring water stress and arboreal forests situation under different irrigation systems using satellite images
Abstract
Egypt offers a great opportunity for large-scale afforestation due to availability of sufficient desert lands and huge volume of sewage water. Several forest plantations were established that irrigated with treated waste water using different irrigation systems. Improper management and failure of irrigation system led to water stress and negative impact of wood trees planted in this man made forests. This study was amid to investigate the use Sentinel-2 satellite images for monitoring the condition of planted wood trees in Luxor Forest planation under the developed surface irrigation system and Serapium Forest planation under drip irrigation system, and estimating the efficiency of biophysical indices and NDWI derived from high resolution satellite imagery for detection spatial and temporal water stress of woody trees at planted forests in Egypt. Biophysical indices including leaf area index (LAI), canopy chlorophyll content (CCC), canopy water content (CWC), fraction of absorbed photosynthetically active radiation (FAPAR), and fraction canopy cover (FCOVER), in addition to NDWI were derived from Sentinel-2 high resolution images using SNAP software. Results indicated that LAI values for Serapium forest during the winter and summer seasons show no changes. However in Luxor forest, LAI values ranged from 0 to 1.293 in winter season and in the summer season LAI recorded higher values that ranged from 0 to 2.383. This shows that woody trees in Luxor forest planation were flourish and had higher growth rates and better condition comparing with woody trees in Serapium forest. Overall, both Serapium forest and Luxor forest had low values of canopy water content during winter and summer season, which indicates that woody trees were under water stress due to not receiving the recommended amount of irrigation water. However, using developed surface irrigation system in Luxor forest resulted in better forest condition compared with drip irrigation.
