Based on the daily observation data of Changling during 1961-2020,the FAO Penman-Monteith method was applied to calculate the reference crop evapotranspiration ET0.Calculated crop water deficit index CWDI and crop water deficit anomaly index CWDIa according to the national standard of agricultural drought grade,calculated the frequency of drought,light drought,moderate drought,heavy drought and extreme drought in maize production every ten da和ys from May to September based on crop water deficit anomaly index,drought grade standard and drought disaster risk assessment method,This research systematically analyzes the occurrence regularity of drought from May to September in 60 years.The results showed that the frequency of light drought,moderate drought and heavy drought was less than 10%in May and September,and the frequency of extreme drought was the highest.Extreme drought and drought appeared two peaks in the early mid of June and early mid of September,The frequency of drought from end of June to end of August is the lowest in the growing season.The frequency of light drought,moderate drought,heavy drought,extreme drought and drought was the highest in 2001-2010,and the frequency of drought was the lowest in 2011-2020.The light drought in September showed an increasing trend with the years,The moderate drought from mid of July to mid of August has an increasing trend with the years,The frequency of heavy drought keeped higher in early mid May and from end of August to mid of September.The frequency of extreme drought keeped higher in all years and The frequency of extreme drought from mid of July to end of August keeped an increasing trend.
关键词
参考作物蒸散量/干旱/作物水分亏缺指数/作物水分亏缺距平指数
Key words
reference crop evapotranspiration/drought/crop water deficit index/water deficit anomaly index
维普
万方数据