Using remote sensing techniques and analytical hierarchy process to select rainwater harvesting optimum sites: a case study in Ali Al-Garbi city, Iraq

Abstract

     The assignment of suitable sites for water harvesting techniques is a promoted strategy to be introduced to the community, for handling the water scarcity and risk due to floods. In the eastern part of Missan, water is always hampered due to the limited availability during the drought, while floods frequently and intensely occur in the wet season. This study aimed to choose the potential and suitable sites for applied water harvesting system using remote sensing techniques and analytic hierarchy process (AHP). Ali Al-Garbi city is divided into three watersheds (site1, site2, and site3), which have been characterized by flash floods that produce high quantities of runoff. The six parameters: slope, lineament density, drainage density, soil texture, rainfall, and runoff. These factors are selected based on previous studies to detect the potential zones of water harvesting system in the study area.Pairwise comparison method consistency index, consistency ratio, and parametersweight is evaluated. The result discovers that the highly probable zone is situated in the north and north-eastern portions in watershed no.1 and watershed no.2, while watershed no.3 located in the south portions. In contrast, the low to medium WH is situated in the center and south portion in watershed no.1 and watershed no.2, whereas in watershed no.3  located in the north.