Your search found 2 records
1 Zhou, X.; Zhang, Y.; Sheng, Z.; Manevski, K.; Andersen, M. N.; Han, S.; Li, H.; Yang, Y. 2021. Did water-saving irrigation protect water resources over the past 40 years? a global analysis based on water accounting framework. Agricultural Water Management, 249:106793. [doi: https://doi.org/10.1016/j.agwat.2021.106793]
Water conservation ; Irrigation water ; Water accounting ; Irrigation efficiency ; Water use efficiency ; Technology ; Estimation ; Water resources ; Water extraction ; Irrigated land ; Evapotranspiration ; Satellites
(Location: IWMI HQ Call no: e-copy only Record No: H050288)
(11.70 MB)
Water-saving technologies have long been seen as an effective method to reduce irrigation water use and alleviate regional water shortage. However, growing reports of more severe water shortage and increasing application of water-saving technologies across the world have necessitated reassessment of agricultural water-saving. This study develops a simple method based on satellite-based ET partitions to estimate water withdrawal, water consumption and return flow from the 1980s to 2010s, and quantifies water-savings across globe and four hot-spot irrigated areas at both field and regional scales based on water accounting framework. The results show that global irrigation water flows keep increasing from the 1980s to 2010s, with over 50% increase from the expansion in irrigated lands. While water-saving technologies are found mainly applied in originally old irrigated lands, traditional flooding irrigation is still dominant in newly-developed irrigated lands. Non-beneficial water consumption (soil evaporation) is effectively reduced by water-saving technologies, but return flow has increased at the same time. At field scale, water-saving technologies fail to save water because the accumulated increased return flow is more than the accumulated decreased non-beneficial water consumption. At regional scale, however, water is saved because the return flow percolated to fresh aquifers is seen as beneficial rather than loss. At the same time, the accumulated increase of beneficial water consumption (crop transpiration) exceeds regional water savings, which explains the paradox between wide application of water-saving technologies and more severe regional water shortage. This study provides key new evidence for the paradox of irrigation efficiency and helps reconsidering water-saving technologies and their impacts on regional water resources.
2 Han, S.; Xin, P.; Li, H.; Yang, Y. 2022. Evolution of agricultural development and land-water-food nexus in Central Asia. Agricultural Water Management, 273:107874. (Online first) [doi: https://doi.org/10.1016/j.agwat.2022.107874]
Agricultural development ; Irrigated land ; Water requirements ; Food production ; Nexus approaches ; Crop water use ; Irrigation water ; Data envelopment analysis ; Surface water ; Rainfed farming ; Wheat ; Cotton ; Maize ; Barley ; Rice ; Evapotranspiration / Central Asia / Aral Sea / Kazakhstan / Uzbekistan / Turkmenistan / Kyrgyzstan / Tajikistan
(Location: IWMI HQ Call no: e-copy only Record No: H051397)
(3.41 MB)
Agricultural water use in heavily irrigated regions can reduce surface water flow. The most remarkable hydrological change in recent times in Central Asia is the rapid dry-up of the Aral Sea. In this paper, the evolution of agricultural development was traced back to the 1910s, Land-Water-Food (LWF) nexus in Central Asia was evaluated, and the relationship between agricultural development and Aral Sea dry-up was built. It was noted that for the 1910–2010s, the harvested land area in the region expanded nearly two folds — from 7.2 to 21.6 million ha. Production of cereal crops increased over eight folds — from 4.0 to 37.6 million tonnes. Cotton production reached 5.5 million tonnes, a seven-fold increase. The high increase in productivity was driven by increasing agricultural irrigation since the 1950s. Irrigation water requirement for the five main crops (wheat, cotton, maize, barley and rice) increased by about 50%; from 64.3 km3 in the 1950s to 95.9 km3 in the 2010s. Cotton and wheat were the top two crops, with respective total irrigation water use of 66.9% and 16.4%. For the study area, LWF nexus was quantified in terms of production efficiency using the data envelopment analysis method, and it was shown that excess water and land resources made agricultural production inefficient. Analysis of the irrigated area and the Aral Sea water surface area suggested that for every 1.0 km2 increase in irrigated land area, water surface area in the Aral Sea declined by 1.2 km2. The analysis of LWF tradeoff was key not only for sustainable land, water and ecological management, but also for food production in degraded arid lands around the globe.
Powered by DB/Text WebPublisher, from
