关键词: 农业干旱, 干旱影响强度, 干旱成灾强度, 气候变化

Abstract: Droughts are the most frequent natural hazards which have caused the second most economic loss in China. In recent years, the trend of annual air mean temperature has been gradually decreased and precipitation has been increased in China. The research of temporal and spatial characteristics of agricultural drought is focused on under new climate background. In order to adapt to climate change and take actions for government and farmers, the spatial patterns, frequency, long-term trends and stage variability characteristics of agricultural drought were analyzed using provincial drought disaster data from 1951 to 2018. The results showed that: (1) the mean area affected by drought, area of drought disasters, area percentage affected by drought and area percentage of drought disasters were used to represent spatial characteristics. Area affected by drought and area of drought disasters were more serious in Inner Mongolia, Shanxi and Hebei province than those in other regions. (2) Based on Warning Grade of Agricultural Drought GB/T 34817−2017 and the definition of area affected by drought, extreme drought, severe drought and moderate drought were classified. The frequency of agriculture drought was more in Inner Mongolia, Shanxi and Shaanxi province than that in other regions. (3) Annual area affected by drought, area of drought disasters, area percentage affected by drought and area percentage of drought disasters were analyzed by fitting at least squares principle. Regression coefficients were used to analyze long-term trends of those four indices. Area affected by drought and percentage experienced decreasing trends in 16 provinces, while they showed increasing trends in most regions with area of drought disasters in 23 provinces and percentage in 27 provinces. (4)According to climate warming trends in China, nearly 70 years were divided into three stages, 1951−1984(stage I), 1985−1997(stage II) and 1998−2018(stage III). It was found that agriculture drought was comparatively less at stage I in China, and it was increasing apparently at stage II. Area affected by drought, area of drought disasters and area percentage affected by drought decreased widely, but area percentage of drought disasters was continued to increase at stage III. Above all, agricultural drought was severer and more frequent in the north of China than that in the south of China, so more attentions should be paid to defending agriculture drought in the north of China.

Key words: Agriculture drought, Area percentage affected by drought, Area percentage of drought disasters, Climate change