关键词: 旱涝演变;气候变化;El Ni1o/La Ni1a事件;太阳黑子;河南省;

Abstract: In order to explore the variation law of drought-flood in Henan Province and its driving factors, based on the daily precipitation and temperature data of 17 national meteorological stations during 1960 to 2018, evolution features of drought-flood and their climatic background in Henan Province were analyzed by using homogenized drought-flood index (DFI) of precipitation and potential evaporation. The results showed that: ① The trend of drought and flood in Henan Province changed reversely around the mid-1990s, showing characteristics of increasing drought times and coverage in different degrees in all seasons. Moreover, except winter and summer, other seasons showed a significant drought trend. This trend would continue to increase in all seasons in the future. ② On the whole, the spatial distribution showed characteristics of drought in central and western regions, flood in central and east of southern Henan. ③When the Sea Surface Temperature (SST) in Ni?o3.4 area was abnormally low, especially in formation of La Ni?a event, it was prone to drought, on the contrary El Ni?o event was prone to flood. Drought and flood had obvious lag response and seasonal changes to El Ni?o / La Ni?a events. The eastern type of El Ni?o / La Ni?a events and central type of La Ni?a events had a prominent impact on drought and flood, however El Ni?o / La Ni?a events of different grades had not significant influence on drought and flood. ④ Flood and extreme flood were prone to occur in sunspot m, m-1 and M+1 years (m is the minimum year, M is the maximum year), while drought and extreme drought were prone to occur in M, M-1 and m+1 years. Moreover, the frequency range of flood in sunspot m, m-1 and M+1 years was significantly higher than that in M and M-1 years, while the frequency range of drought in M, M-1 and m+1 years was significantly higher than that in m and m-1 years. ⑤The evolution of drought and flood in Henan Province had periodic response to Sea Surface Temperature Anomaly (SSTA) and sunspot activity, and had obvious hysteresis. The research results can provide reference for flood control and drought resistance work in Henan Province.

Key words: drought-flood evolution; climate change; El Ni?o / La Ni?a events; sunspot; Henan Province