新疆雪灾的时空分布特征及其等级划分

利用新疆1954—2018年雪灾资料分析其灾害时空特征，时间上雪灾灾损强度在90年代后出现明显加大，2010年出现跃增特点，空间上雪灾灾损强度新疆西部多于东部，北部多于南部，山区多于盆地或平原。用雪灾出现次数、房屋倒塌间数、牲畜棚圈倒塌间数、损坏大棚数、死亡牲畜数、受灾面积、经济损失等多指标综合分析法来客观构建灾损指数，符合Γ分布的灾损指数结合F分布函数能客观的描绘出雪灾等级，分为一般、较重、严重、特重4个等级。根据构建的雪灾等级，发现新疆雪灾特重灾区集中在天山山区及其以北地区，南疆仅有喀什地区为特重灾区。

Spatial and temporal distribution characteristics and its classification of snow disaster in Xinjiang

Located at the center of Eurasia,Xinjiang has a vast area of 1.66 million square kilometers,accounting for one-sixth of China.The landform of Xinjiang can be roughly summarized as “three mountains sandwiched between two basins,”the mountains being the Kunlun,Altun,and Tianshan Mountains and the basins being the Tarim and Junggar basins.Tianshan Mountains crosses the central part of Xinjiang.Snow exists at the top of the mountain year-round,and its environment is extremely harsh,with frequent disasters.This paper analyzes the temporal and spatial characteristics of disasters using 403 effective sample sequences of snow disaster statistics from 1954 to 2018 in order to construct a disaster index using multi index comprehensive analysis methods,such as the number of snowstorms,the number of collapsed houses,the number of collapsed livestock sheds,the number of damaged sheds,the number of dead animals,the area affected,and economic losses,among other parameters.Subjective factors are therefore excluded.The disaster index consistent with a combination of the Γdistribution and the F distribution function can objectively depict the risk of snow disaster.This risk can be divided into four levels:general,heavier,serious,and extra heavy.The intensity of snow disasters has increased significantly since the 1990s,showing a significant increase in 2010.On the spatial scale,the intensity of snow disasters is higher in western Xinjiang than in the east,higher in the north than in the south,and higher in the mountains than in the basins or on the plains.According to the intensity of snow disaster calculated in this paper,the snow disaster area in Xinjiang is concentrated in the Tianshan Mountains and its northern areas.The Kashi Prefecture in Southern Xinjiang is also a disaster-prone area.Grave disasters account for only approximately 10% of all snow disasters.By contrast,around 50% of snow disasters are classified into the general level,whereas heavier and severe snow disaster each account for about 20%.