The Tigris River Basin in the Context of Water-Energy-Environment Systems: Climate Change and Sustainability Analysis at the Scale of Turkey and Iraq

This study analyzes the contemporary hydrological dynamics, energy generation, and agricultural irrigation projections of the Tigris River Basin through the "Water-Energy-Environment" nexus. It evaluates the impacts of climate change and infrastructural developments on upstream (Turkey) and downstream (Iraq) ecosystems. Findings reveal a critical "Investment-Resource Paradox" in the upper basin: despite climate-induced droughts reducing natural discharge by 20–30%, Turkey’s water-dependent agricultural and hydroelectric capacities are expanding rapidly. Conversely, downstream Iraq faces a hydrological collapse due to a "triple squeeze": upstream regulations by Turkey, damming of eastern tributaries by Iran, and inefficient domestic irrigation. This crisis has caused severe ecological degradation, including the desiccation of the Mesopotamian Marshlands and saltwater intrusion, acting as a threat multiplier for socio-economic instability. The study concludes that traditional supply-oriented management is unsustainable. Securing the nexus requires a shift towards demand management, focusing on agricultural efficiency (digital micro-irrigation), binding environmental flow protocols, and a tripartite (Turkey-Iraq-Iran) multilateral basin diplomacy mechanism to govern shared climate risks.