Impacts of climate extremes on agricultural water scarcity under historical and future periods and the spatial scale effect
- 1State Key Laboratory of Efficient Utilization of Agricultural Water Resources, Beijing 100083, China.
- 2National Field Scientific Observation and Research Station on Efficient Water Use of Oasis Agriculture in Wuwei of Gansu Province, Wuwei 733000, China.
- 3Center for Agricultural Water Research in China, College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
Background
Both blue water and green water contribute to agricultural water scarcity, which is subjected to impacts of escalating climate extremes, e.g., precipitation and temperature extremes. However, an explicit quantification of the possible effects of compound climate extremes on agricultural water scarcity index (AWSI) under historical and future climate is absent and current research often overlooks how different spatial scales influence agricultural water scarcity.
Methods
We applied an integrated AWSI, which incorporates blue water and green water, to estimate agricultural water scarcity in provincial and basin scales in China, and to determine the association of AWSI with compound climate extremes over the historical period 1971–2010 and for future period 2031–2070.
Conclusions
Our results indicate a marked escalation in AWSI during dry years and periods of elevated temperatures, and precipitation significantly impacts AWSI more than temperature variations. In secondary basins, AWSI was about 25.7% higher than the long-term average during dry years, increasing to nearly 49% in exceptionally dry conditions. Comparatively, in tertiary basins, the increases were 27.7% and 55%, respectively. In years characterized by high temperatures, AWSI rose by approximately 6.8% (7.3% for tertiary basins) from the average, surging to around 19.1% (15.5% for tertiary basins) during extremely hot periods. Future climate change would further intensify AWSI and amplify the effects of climate extremes, particularly in Inner Mongolia with changes of AWSI over 200%. Southwestern China could also experience expanding agricultural water scarcity under future climate scenarios. Improving irrigation efficiency has potential to alleviate water scarcity by up to 30%. Moreover, it illustrates that AWSI assessment at the tertiary basin level could better capture the influence of climate extremes on AWSI compared to assessments at the secondary basin level. As a whole, the investigation offers an in-depth evaluation of the influence of compound precipitation and temperature extremes and research scale on water scarcity.
How to cite: Liu, J. and Liu, W.: Impacts of climate extremes on agricultural water scarcity under historical and future periods and the spatial scale effect, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14467, https://doi.org/10.5194/egusphere-egu24-14467, 2024.
Corresponding supplementary materials formerly uploaded have been withdrawn.