CRU产品在中国大陆的干旱事件时间性效用评估

基于1980—2016年CGDPA(China gauge-based precipitation daily analysis dataset)和PM-Ep(potential evapotranspiration calculated by Penman-Monteith)资料，以标准化降水蒸散指数(SPEI)为干旱指标，采用6种评估指标综合评价CRU降水(CRU-P)和潜在蒸散发(CRU-Ep)产品在中国大陆对干旱事件时间性的监测效用。结果表明:CRU-P与CGDPA在中国大陆空间分布特征具有较好的相似性，而CRU-Ep与PM-Ep有明显差异，但它们在大部分地区的精度较高；SPEIc(基于CRU-P和CRU-Ep计算的SPEI)在中国东部和西部部分地区的性能较好，其与SPEIm(基于CGDPA和PM-Ep计算的SPEI)的相关系数在中国东部、西北、西南地区均大于0.7，均方根误差小于0.8，命中率大于0.6；利用文中提出的干旱率、平均开始时间误差、平均结束时间误差评价得出不同时间尺度的SPEIc在中国大陆大部分地区监测干旱事件时间性的精度较高，且在中国东部地区优于西部地区；基于长序列CRU产品驱动的SPEI可适用于中国东部、西北、西南地区的干旱监测。

Utility assessment of CRU products for temporality of drought events in mainland China

Based on the CGDPA(China gauge-based precipitation daily analysis dataset)and PM-Ep(potential evapotranspiration calculated by Penman-Monteith)datasets during 1980-2016, the standardized precipitation evapotranspiration index(SPEI)and six evaluation indicators were used to evaluate the performance of CRU precipitation(CRU-P)and potential evapotranspiration(CRU-Ep)products for monitoring the temporality of drought events in mainland China. The results showed that the spatial distribution characteristics of CRU-P and CGDPA feature better similarity in mainland China, while CRU-Ep and PM-Ep are obviously different, but they are more accurate in most areas. SPEIc(SPEI value based on CRU-P and CRU-Ep)had a good performance in eastern and parts of western China. The correlation coefficient between SPEIc and SPEIm(SPEI based on CGPDA and PM-Ep)is greater than 0.7, the root mean square error is less than 0.8 and the hit rate is greater than 0.6 in eastern, northwest and southwest China. The SPEIc with different timescales, which was assessed by using the probability of drought event, mean start time error and mean end time error proposed in this paper, has a high accuracy in monitoring the temporality of drought events in most parts of mainland China, and it is better in eastern China than in western China. SPEI based on long series CRU products can be applied to drought monitoring in eastern, northwest and southwest China.