Water scarcity and other stressors disrupting system order in Iraq transboundary basins

Iraq and transboundary regions of the Middle East face complex environmental challenges of water scarcity in combination with other stressors including population growth and migration. Since Iraq is highly dependent on upstream water management to meet its water demands, there is an urgent need to address various factors of transboundary watersheds such as the Qadisiyah, Mosul, Dukan, and Tigris-Euphrates river basins. In this multidisciplinary study, societal and hydrology variables are used to develop a risk register of basins in which the priorities of agencies vary across hydrology scenarios. Publicly available satellite-based Earth observations and models are used to obtain hydrology data. These include precipitation data from the Integrated Multisatellite Retrievals for Global Precipitation Measurement (GPM IMERG), air temperature and root zone soil moisture data from the Global Land Data Assimilation System (GLDAS), and normalized difference vegetation index (NDVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS). The methods of this study are as follows. First, a baseline order of basins is defined using population dynamics from 2010 - 2020. Then, a variety of hydrology scenarios are analyzed using a swing-weight method. Lastly, the disruption of scenarios to the baseline order is compared to identify basins with the highest water scarcity risk given priorities of population growth and hydrology. The innovation of this work is the integration of population data and remotely sensed hydrology data in a decision tool for infrastructure systems vulnerable to water scarcity and other stressors. Results of this work can be used to inform priorities and future investments aimed to decrease risk of disrupted system orders and to increase system resilience to water scarcity for Iraq and its transboundary basins.