Agricultural drought characteristics identification and analysis of Henan Province in China

摘要

In Henan Province the impact of drought on agricultural production is severe, and agricultural drought has become a seriousproblem, restricting economic development. Agricultural drought characteristics were studiedusing run theory followed by intensive analysis of precipitation data across the province. The data analysis focused on 18 sites in Henan Province from which data (1951-2010) was selected and the Mann-Kendallmethod was appliedin the analysisof trends in precipitation, percentageof precipitation anomalies, total frequency of drought, and occurrence frequencies of four drought levels. The average annual rainfall in Henan Province showed a trend of increasing precipitation, but the trend was weak and basically stable. Meanwhile, the annual rainfall fluctuation wasgreater. For precipitation and precipitation anomaly percentage, there was an increasing trend in the southern region and a decreasing trend in northern region, which indicated that northern Henan Province has suffered more drought thanthe southern region. Further investigation using multi-scale wavelet analysis for years with distinct precipitation anomaly percentagesrevealed two main cycles of 10 and 22 years for agricultural drought in Henan province.