Leveraging atmospheric moisture recycling in Saudi Arabia and neighboring countries for irrigation and afforestation planning

Abstract

Abstract Effective irrigation planning is crucial for sustainable agricultural development and ecosystem restoration projects in arid regions. With respect to ambitious greening initiatives, Saudi Arabia is establishing a national strategy toward a more sustainable and eco-friendly future not only for itself but also for the broader Middle East region. Thus, comprehensively understanding the water cycle in the region is essential to identify the most suitable target locations for afforestation and reforestation while considering the potential role of irrigation. Herein, in addition to traditional pedoclimatic factors, we introduce a complementary consideration—“irrigation recycling.” Building on the well-established concept of atmospheric moisture recycling and taking advantage from an atmospheric trajectory dataset, we track the path of evaporated water from current or potential irrigated sites to the location where the evaporated water eventually falls as precipitation. Our analysis offers two key benefits. First, it helps pinpoint the regions in which and the periods during which water recycling is maximum within the country, aiding more precise calculations of the investment return value for irrigation infrastructures. Second, it helps identify the land-use change patterns that contribute to international efforts such as drought mitigation in East Africa as an example. We found that one-third of the actual precipitation in the current Saudi irrigated sites originated from evapotranspiration over land, mainly from Saudi Arabia and surrounding countries. Interestingly, most of the evapotranspiration from these irrigated sites will eventually fall somewhere over land (primarily in Iran). Controlling the seasonality and spatial distribution of the future irrigation expansion will allow controlling the atmospheric moisture recirculation in Saudi Arabia and nearby drought-prone regions such as Eastern Africa. The outcomes of this study will be the subject of future integrated assessments to account for the climatic feedbacks of the land-use change scenarios. At present, they provide crucial insights to support the decision-making process surrounding the Saudi and Middle East Green Initiatives. Further, the presented methodology offers a pragmatic framework that can be applied to similar greening projects for other regions, making it a viable and valuable approach for global sustainability programs.