Threshold Drought and Flooding at Critical Growth Period of Winter Wheat in the Upper Reach of Huai River
YIN Zhouxiang
GAO Chao
LI Xuewen
RUAN Tian
Abstract：Using the precipitation measured daily from 1961—2015 at 13 weather stations in the upper reach of Huai River, we calculated the monthly average and quarterly average SPI of winter wheat during its main grow-ing season (February to March) respectively. Based on the harvest time, we calculated the yield loss rate due to the occurrence of drought and/or flooding in different growing stages, from which we analyzed the spatial distri-bution and variation of the precipitation, flooding and drought, as well as their relationship with the SPI. The re-sults showed that there was a close correlation between SPI3 for critical growing stage and the SPI for April (SPI4), which passed both the 0.01 and 0.05 confidence tests. The precipitation during the two periods decreased, and there was a difference in the spatial distributions of the drought and flooding as well. The threshold at which a drought could cause agricultural loss was when SPI3 was-2.23 and SPI1_4 was-1.82. The correlation coeffi-cients of SPI3 and SPI1_4 with the agricultural loss rate were 0.94 and 0.82 respectively, and there was a linear re-lationship between SPI and agricultural loss rate in typical flooding years.
Keywords：SPIwinter wheatgrowth critical periodthreshold of drought and flood disasterupper reaches of Huaihe River
Publication Date：2017-01-01
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：8( 100-107 )