Quantitative Assessment of the Water Stress in the Tigris-Euphrates River Basin Driven by Anthropogenic Impacts

Water stress has induced many environmental and developmental conflicts in the arid basins in the Middle East region under the context of climate change and increasing anthropogenic influence. Quantifying the anthropogenic influence on water stress at the basin scale is very challenging because of insufficient anthropogenic-related spatial data. Given that climate change is a global impact that is hard to mitigate at the basin scale, quantifying anthropogenic influence is practical to inform strategies for alleviating regional water stress. Thus, this study attempts to quantify the contribution of potential anthropogenic factors driving the water stress in the Tigris-Euphrates river basin (TERB) using pure spatial data. The water stress level in the studied basin was evaluated via the water stress index (WSI), which can be obtained as the ratio of water demand to water availability, from the Aqueduct 4.0 dataset. The driving contributions of social development (population, POP; fine particulate matter, PM2.5), economic development (gross domestic product, GDP; electricity consumption, EC), and landscape modification (urban expansion index, UEI; cultivated land expansion index, CEI) factors were quantitatively evaluated based on a spatial statistical geographical detector model (GDM). Assessment showed that nearly 66.13% of the TERB area was under severe water stress, particularly in Syria, Iraq, Saudi Arabia, and Iran. The q statistic of the GDM, adopted to quantify the contribution of driving factors, revealed that CEI (0.174), EC (0.145), and GDP (0.123) were the dominant factors driving water stress. These individual influences were further enhanced particularly in the interaction between economic development and landscape modification factors such as UEI and CEI (0.566), PM2.5 and UEI (0.350), EC and CEI (0.346), GDP and CEI (0.323), and PM2.5 and GDP (0.312). The findings of this research can provide some beneficial references to alleviate the TERB's water stress for its future sustainable development.