Unraveling agricultural water use in three Central Asian irrigation oases using remote sensing

Study Region: Three major irrigation oases in Uzbekistan (Bukhara, Samarkand and Kashkadarya)

Study focus: The study employs remote sensing to develop enhanced methodologies for quantifying water use in Central Asian irrigation oases from 2017 to 2022. By integrating earth observation data into a water balance approach, we quantify variables that are typically challenging to measure, such as groundwater overdraft and non-growing season water use for soil preparation. A key aspect of agricultural water management in the region is utilizing water from reservoirs. Here we introduce a novel approach that combines optical remote sensing with satellite laser altimetry to monitor the availability and use of active water storage in reservoirs.

New hydrological insights for the region: Results indicate that water from reservoir storage satisfies up to 14.9 % ± 2.2 % of the annual demand, but another 11.5 % ± 5.2 % are groundwater withdrawals. Our analysis indicates a necessary average annual reduction in groundwater extractions by at least 8.0 % ± 1.6 % for sustainability. Additionally, highly energy-intensive water pumping from Amu Darya River provides more than half of the water resources used in Bukhara and Kashkadarya, resulting in a significant carbon footprint of the region’s agricultural production. The detailed breakdown of water uses and irrigation water consumption by crop type informs efficient, sustainable water management, offering new opportunities for agricultural water accounting in Central Asian irrigation oases.

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