暴雨灾害 (Apr 2021)
Simulative projection of future choking drought disaster risk of summer maize in the Huaihe River basin under RCPs scenarios
Abstract
To evaluate the climate variation of drought and its possible effect on summer maize in the Huaihe River basin, we have used the five General Circulation Models (GCMs) from the fifth coupling model comparison scheme (CMIP5) and the diurnal temperature and precipitation data under three representative concentration pathways (RCPs) to calculate the frequency of drought beyond the different disaster-causing thresholds based on the historic disaster losses. Combined with the vulnerability and exposure of hazard-affected bodies, we have established a regional disaster drought risk evaluation model, and conducted a risk estimation to the choking drought disaster occurred in heading-milking period of summer maize in the Huaihe River basin in the near term (2020-2039), medium term (2040-2069) and long term (2070-2099) in the 21st century. The results show that the five GCMs have good ability in simulating temperature and precipitation in the Huaihe River basin, especially temperature. The heading-milking period (critical period of water sensitivity) of summer maize will be ahead of schedule, and the growth period will be shortened. It is estimated that the inter-annual change of the choking drought days in the heading-milking periods of summer maize in the Huaihe River basin is large in the future. Linear change trends of the choking drought days of summer maize are not significant under RCP4.5 and RCP8.5 scenarios, although this linear increased trend is significant under RCP6.0 scenarios. Affected by the disaster-causing factors and the hazard affected bodies, the inter-annual fluctuation of choking drought risk of summer maize in Huaihe River basin will be large in the future. The overall drought risk will increase compared to the base period. In terms of different periods, the risk of drought disaster can be the lowest in the medium term, the second in the near future, and the highest in the long term. The choking drought risk in the different scenarios increases from low to high emissions. It is estimated that the risk of drought disaster of summer maize has an obvious spatial difference, and the drought risk in the western and northern parts in the Huaihe River basin can be higher than those in the eastern and southern parts.
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