| Cite this article: | 刘海军,唐晓培,杨丽.极端降水引起的大面积夏玉米减产方法研究——以2021年河南“720”强降水事件为例[J].灌溉排水学报,2022,(12):-. |
| LIU Haijun,TANG Xiaopei,YANG Li.极端降水引起的大面积夏玉米减产方法研究——以2021年河南“720”强降水事件为例[J].灌溉排水学报,2022,(12):-. |
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| DOI： |
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| Approach for evaluating summer maize yield losses under extreme rainfall events——A case study in “720” heavy rain event in Henan Province |
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LIU Haijun, TANG Xiaopei, YANG Li
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Beijing Key Laboratory of Urban Hydrological Cycle and Sponge City Technology,College of Water Sciences,Beijing Normal University
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| Abstract: |
| 【Objective】This study aims to develop a quick and reliable method to evaluating crops response to flood under extreme rainfall condition. Then the developed method was sued to evaluate the impact of “720” heavy rain in 2021 on summer maize production in Henan Province. 【Method】Based on daily normalized vegetation index (NDVI) remote sensing images and DEM data of Henan Province from June 18 to July 29, 2021, the continuous flooded area of summer maize in Henan Province in “720” heavy rain event was estimated by pixel statistics method. Then, according to the relationship between flooded duration and maize yield reduction and the compensation effect of topdressing on flooded maize yield, the loss of summer maize yield caused by the “720” rain event in Henan Province was evaluated.【Result】The flood region caused by the “720” rain event was mainly distributed in the north of Henan Province, including Anyang, Xinxiang and Zhengzhou regions. This heavy rain resulted in a total of flooded summer maize field of 39.09 million mu, in which 8.51 million mu was moderately flooded area (continuous flooded for 3 days), 1.95 million mu of severe flooded area (continuous flooded for 5 days), and 2.96 million mu without grain harvest (continuous flooded for 7 days).【Conclusion】The “720” heavy rain directly resulted in 3.93-4.91 million tons loss for summer maize grain, accounting for 17%-22% of the total maize production of the province (based on the maize production in 2019). This loss rate is close the field survey result. It can be concluded that, the developed method for quickly determining flood region of maize and estimating maize losses is acceptable and can be used in estimating maize production after extreme rainfall and national food security research. |
| Key words: Heavy rain; Summer maize; Flooding area; Yield losses assessment; Food security |
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