Assessment of groundwater quality in the Al- Burayhi and Hedran sub-basin, Taiz, Yemen – A GIS approachRamzy Naser, Mohammed El Bakkali, Nabil Darwesh, Khadija El Kharrim and Driss BelghytiE3S Web Conf., 37 (2018) 01005DOI: https://doi.org/10.1051/e3sconf/20183701005