Abstract: Drought occurs when precipitation is significantly lower than normal and it has been one of the most severe disasters all over the world. It can cause huge agricultural and economic loss when lasting for a long time. Hubei Province is located in the middle reaches of Yangtze River basin, which belongs to the temperate continental monsoon climate zone. It plays an important role in agricultural production of China. Recently, more frequent drought has occurred in Hubei Province and caused heavy losses. The basic characteristics of drought and its spatiotemporal patterns in this region need to be understood comprehensively. Quantitative analysis is useful to implement the suitable measures for drought mitigation. Based on standardized precipitation evapotranspiration index (SPEI) at different time scales, the meteorological data of 40 observation stations were used to analyze the characteristics of drought in this region. The objective of this study is to analyze drought in Hubei Province and describe its patterns from various aspects objectively and quantitatively, and to provide basis for moving forward and taking counter measures. The SPEI has been widely used for drought analysis and monitoring because of its robustness in multiple time scales. The role of evapotranspiration is also been included in the calculation of SPEI, which can represent water balance well from point of input and output. The evaluation indicators include drought frequency, drought stations proportion and drought intensity. The results showed that drought was widespread in Hubei Province, since 54% of years during 1961-2012 were identified as large-scale drought. However, the drought was not severe. The average intensity was 0.65. Severe drought only occurred in 2 years over the recent 52 years, while slight and moderate drought years accounted for 85%. Both of drought intensity and drought stations proportion has increased during the last 52 years (the tendency is 0.041/10 a and 3.692/10 a respectively.) Specifically, they decreased before the 1980s and then increased significantly after the 1980s. And it's obvious that 1980s was a period of transition which had lowest drought intensity and drought frequency. The similar results have been found from the viewpoints of the average drought intensity, the drought frequency and the drought area. This is consistent with previous studies in South China. Spatially, the drought frequency was higher in the east and lower in the west, ranging from 16.5% to 18.2%. From interdecadal views, the drought frequencies in the 1970s and the 1980s were the lowest (high-incidence area of drought was small in the 1970s and the 1980s), and increased after the 1980s. After the 2000s, the drought intensity, drought frequency and drought area all increased obviously and tended to continue increasing. And the spatial difference of drought frequency was also increasing. The results are in line with previous studies and records, which also indicated that SPEI was suitable for drought analysis in Hubei Province.

Key words: drought, Hubei Province, SPEI, temporal and spatial distribution