【摘要】 以西藏38个气象站点1985-2014年实测降水量为基础数据,应用灰色预测模型和长序列趋势拟合方法预测2015-2019年的年降水量和季节降水量,经2015-2017年的实测降水数据验证,其结果良好,最后以调整后的降水距平百分率为洪涝指标,分析2018年、 2019年的洪涝预测情况。结果表明,西藏2018年降水集中在东南部地区的林芝、米林、波密和察隅一带, 2019年降水主要集中在芒康地区,季节上春季降水主要集中在雅鲁藏布江大拐弯地区,夏季主要在索曲河、怒江上游地区,秋季主要在嘉黎、林芝、波密一带,冬季降水集中在聂拉木地区。2018年和2019年洪涝易发生在春季和冬季,洪涝情况都相对正常,大部分县区为无涝或正常状态,少数县区为轻微洪涝,极少数县区为中涝或特涝, 2019年洪涝情况相较于2018年整体偏多,其中在2018年的拉孜县和2019年的拉萨城关区,极有可能出现特涝灾害。更多还原

【Abstract】 Precipitation is a principal condition for flood. In this paper, based on precipitation data from 38 meteorological stations in Tibet, 1985-2014, as the basal forecast data, the grey model and the long sequence trend fitting are utilized to predict the yearly and seasonal precipitation in 2015-2019. It was verified by the measured precipitation from 2015 to 2017 that the result is good. Finally, the adjusted precipitation anomaly percentage was used as a flood index to analyze the flood forecast in 2018 and 2019. It is found that in 2018 precipitation concentrated in Nyingchi, Mainling, Bomê and Zayü in southeastern Tibet. Precipitation will mainly concentrate in Markam in 2019. And rainfall mainly occurs in the Great Canyon region of the Yalung Zangbo River in spring, the upper reaches of the Suoqu River and Nu River in summer, Lhari, Nyingchi, and Bomê in the fall, and the Nyalam in winter. Different from summer and autumn, floods will occur frequently in spring and winter in 2018 and 2019. There will be a relatively normal situation of flood in Tibet in 2018, most counties in an unblemished or normal state with slight flood in a few counties and middle or serious flood in a few counties. The flood in 2019 will be more than that in 2018. Additionally, there will be a great possibility for waterlogging disasters in Lhazê County in 2018 and Lhasa in 2019; the local government should pay special attention to the flood prevention during the flood season. These consequences are of profound significance for the flood prevention in Tibet in the next two years.更多还原