Water Scarcity and Rainwater Harvesting Technology in Different Regions in the World: State of the Art

Given the close relationship between water scarcity and water harvesting using various methods, this study monitors and presents a set of research related to both topics. Research on these two topics was presented in three sections, organized according to the climate changes that occur in different geographical locations on the Earth's surface. The first section represents studies conducted in various countries worldwide, excluding those in the Middle East. In contrast, the second part symbolizes the research completed in the Middle East, excluding Iraq, and the third part includes a group of studies conducted in Iraq. This research will offer an understanding of the influence of climate change that leads to water scarcity, as well as harvesting measures to address this issue.