Hydrographic Features of the Nakhchivan Autonomous Republic: Structure, Distribution, and Agricultural Significance

This article provides a comprehensive hydrographic analysis of the Nakhchivan Autonomous Republic (NAR), a landlocked exclave of Azerbaijan. Nakhchivan’s hydrographic network comprises about 400 rivers (total length ≈1,800 km), most of which drain into the Aras (Araz) River on its southern border. The major rivers – the border Araz (Aras), the transboundary Arpachay (Arpa), and the intra-regional Nakhchivanchay – originate in the Lesser Caucasus mountains and are fed by snowmelt and rainfall. The region’s climate is dry continental, with mean annual precipitation only ~200–350 mm on the Araz plain and 500–800 mm in uplands. Rivers are typically calcium–bicarbonate type, with moderate mineralization (total dissolved solids ~300–500 mg/L) and episodic high turbidity (up to ~1000 g/m³ during floods). Recent studies find that heavy metal concentrations in Aras and Arpachay waters generally meet WHO standards. Nakhchivan’s agriculture (dominated by wheat, barley, fruits) is heavily reliant on irrigation from these rivers and ancient qanat (kahriz) systems. For example, rehabilitation of 125 kahriz tunnels has provided irrigation to ~700 ha of arable land. Educationally, the Nakhchivan river system offers rich case studies in dryland hydrology, transboundary water management, and traditional irrigation. This article reviews physical geography and hydrology, profiles the Araz, Arpachay, and Nakhchivanchay rivers, examines tributary networks and water chemistry, and discusses agricultural uses and teaching applications of these water resources. Citations from recent government and scientific sources are provided throughout.