风沙灾害是造成塔里木盆地农牧业生产严重损害的一种气象灾害。利用1990—2019年塔里木盆地42个县（市）出现的1028次风沙灾害事件,以死亡人数、倒塌房屋数、倒塌棚圈数、损坏大棚数、牲畜死亡数量、农作物受灾面积作为6大灾情要素,采用比值权重和无量纲化线性组合方法,构建能综合表达灾害事件强度的灾损指数,进而利用百分位数法将灾害事件的强度定量划分为一般（1级）、较重（2级）、严重（3级）和特重（4级）4个等级,基于灾害出现次数和灾损指数,分析盆地风沙灾害的时空分布特征。结果表明：盆地风沙灾害春季出现最多、强度最重,且集中在4—5月,盆地北部1~4级出现次数和强度明显大于盆地其他区域,盆地北部是风沙灾害的多发区和重灾区。1990—2019年盆地风沙灾害年出现次数呈显著的线性增加趋势,但年灾害强度围绕气候平均值上下震荡。1级年出现次数和年灾害强度均呈显著的线性增加趋势,而2~4级年出现次数和年灾害强度围绕气候平均值上下震荡。通过创建楼兰指数可从动力气候学角度解释盆地风沙灾害年出现次数长期变化的动力机制。随着盆地东部与西部气压差（楼兰指数）的不断加大,引发盆地4月和5月逐小时10 min平均风速≥6.0 m·s^-1出现次数逐年增多,加之盆地绿洲规模的逐渐扩大,导致盆地风沙灾害年出现次数不断增加。研究结果可为塔里木盆地风沙灾害预报预警和防范提供科学依据。

Sandstorm is a common meteorological disaster that causes serious damage to agricultural production and animal husbandry in the Tarim Basin, Xinjiang, China. Based on the disaster data acquired from the 1028 wind-sand disasters that occurred in 42 counties (cities) in the Tarim Basin from 1990 to 2019, six factors were selected as major disaster elements, namely, death toll, number of collapsed houses, collapsed shed circles, damaged sheds, livestock deaths, and affected areas. The disaster damage index could be integrated to express the intensity of disaster events using the method of ratio scale weighting and the dimensionless approach of linear combination. The intensity of disaster events was quantitatively divided into four levels using the percentile method: general (level 1), heavy (level 2), large (level 3), and extremely large (level 4). The temporal and spatial distribution characteristics of wind-sand disasters in the basin were analyzed in terms of the frequency of occurrence and the disaster damage index. Results showed that the wind-sand disaster hit the basin with the highest frequency and intensity in spring, especially in April and May. The frequency and intensity in the north Tarim Basin were obviously higher than those in other areas in the basin, making it the most frequently and hardest hit area of wind-sand disasters. During 1990—2019, the annual frequency of occurrence of wind-sand disasters in the basin conside-rably increased linearly, but the intensity fluctuated around the climatic average. The annual occurrence and intensity of wind-sand disaster in level 1 also showed a considerable linear increase, whereas level 2-4 varied around the climatic average. The established Loulan index, which is defined as the pressure difference between the east and west parts of the basin, could explain the dynamic mechanism of long-term changes in the frequency of occurrence of wind-sand disasters in the basin based on dynamic climatology. As this index increased during 1990—2019, the occurrence of an average wind speed of more than 6.0 m·s^-1 per hour in the basin from April to May increased per year. The scale of the basin oasis gradually expanded, resulting in the yearly increasing occurrence of wind-sand disaster in the basin. Thus, this study could provide a scientific basis for the prevention of wind-sand disasters in the Tarim Basin.