Temporal and Spatial Changes in Crop Water Use Efficiency in Central Asia from 1960 to 2016

Abstract

Water resources among five Central Asian countries are distributed unevenly. Since the collapse of the Soviet Union, the conflict between water and land use has become increasingly serious. Due to limited data, the temporal and spatial characteristics and trends of crop water use efficiency in Central Asia over the past 60 years remain unclear. This paper combines state-level agricultural statistics data and cultivated land data (1975, 2005 and 2015) from remote sensing imagery and calculates crop water use efficiency based on the FAO crop coefficient method. The results are as follows: (1) the development of crop cultivation in Central Asia is divided into an expansion period (1960–1990), a reduction period (1990–2000), and a recovery period (2000–2016); (2) the grain yield in Central Asia increased from 0.9 to 1.9 t/ha during 1960–2016, with Uzbekistan having the highest, reaching 4.2 t/ha in 2016. Cotton yield increased during 1960–1990 and decreased from 1990 to 2016. (3) The grain water use efficiency in Central Asia increased from 0.22 kg/m3 to 0.39 kg/m3 during 1960–2016. The cotton water use efficiency increased from 0.23 kg/m3 to 0.30 kg/m3 during 1960–1990, has decreased since 1990, and is currently close to the 1960s level.

Remote sensing classification approach to large‐scale crop cultivation identification: A case study of the Aral Sea Basin

“…These trends are similar to the results reported by Liu et al. (2020) and those obtained with the WUEMoCA (Dimov et al., 2017). Our crop classification results matched the existing distribution of arable lands and crop cultivation maps well (Conrad et al., 2016; Dimov et al., 2017; Liu et al., 2020).…”

“…We found that throughout the three periods of study (1991-2000, 2000-2010, and 2010-2019), the cotton acreage showed a "decreasing-stable-decreasing" trend, while the wheat acreage showed an "increasing-stable-decreasing" trend. These trends are similar to the results reported by Liu et al (2020) and those obtained with the WUEMoCA (Dimov et al, 2017). Our crop classification results matched the existing distribution of arable lands and crop cultivation maps well (Conrad et al, 2016;Dimov et al, 2017;Liu et al, 2020).…”

Journal of Water and Land Development

“…The first reason is the constant threat of drought in the region [ZHUPANKHAN et al 2017]. The second reason is the increase in water consumption by industry and households, caused by population growth [LIU et al 2020]. In addition to that, the growing population creates the need for irrigating the agricultural fields more effectively than before.…”