Water Use Modes Significantly Affect Water Cycle and Agriculture Sustainability in Dryland Regions

The over-exploitation of the water cycle has led to a dramatic shrinkage and water reduction of the Aral Sea Lake and water deficit in the agroecosystem of the Aral Sea basin.

The Aral Sea basin is located in Central Asia. About 46.08% of the Aral Sea basin is a desert dominated by a cold desert and arid steppe hot climates. Due to its ecological and hydrological problems, the United Nations has listed the Aral Sea basin as the world’s greatest environmental disaster of the 20th century and calling for international attention to the practical sustainability of the basin's ecosystem.

A research group led by Prof. CHEN Xi from the Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences has investigated the influence of anthropogenic activities and desertification processes on the water cycle and water use in the Aral Sea basin in the period 1986-2022.

The study was published in the Journal of Hydrology: Regional Studies.

According to the researchers, the Aral Sea Lake has experienced a decrease in water surface area by approximately 1.02 x103 km².yr^-1, water volume by 9.59 km³.yr^-1 and water level by 1.14 m.yr^-1, as well as a decrease in agroecosystem water yield by 0.45 mm.yr^-1.

The imbalance between agricultural water demand and water supply has resulted in an annual water deficit for agricultural irrigation of about 0.071 km³.yr^-1 and this water deficit has significantly affected wheat production in Kyrgyzstan and slightly in Afghanistan and Turkmenistan.

The researchers showed that excessive and inefficient water use in agriculture pose the most prominent problems on water cycle in water-limited regions. The application of modern irrigation systems and adjustment of cropping structures are the most effective ways to save water cycles in these regions.  

This study can provide a reference for the water management in Central Asia and other hotspots of the global drylands.

Article link: https://www.sciencedirect.com/science/article/pii/S2214581823002859