陕南秦巴山区极端降水的空间分布特征研究

Spatial Distribution of Extreme Precipitations in Qinba Mountain Area of Southern Shaanxi Province

极端降水是许多突发性和危害性水灾害事件的诱因。陕南秦巴山区因其复杂的地理、气候条件,对极端降水引发的各种灾害风险更为敏感。相关研究可以强化区域极端降水预报和山地灾害预测,指导适应性治理方案制定。依据研究区19个站1998年—2016年的逐日降水资料,采用阈值为95的百分位法筛选不同时段的极端降水,并运用等值线图进行极端降水空间变化特征分析。结果表明:陕南秦巴山区极端降水发生数从南到北递减,西部应重视短历时极端降水引发的山洪和泥石流灾害;其极端降水均值、变差系数等值线多与汉江河道方向一致;易受极端降水危害的是镇巴和佛坪县域,需进行滑坡灾害重点防灾设计。研究丰富了秦巴山区气象数据资料成果,同时也为区域极端降水和山地灾害的预测预报提供了科学的依据。

Extreme precipitation is the cause of many sudden and harmful water disasters. Due to its complex geographical and climatic conditions,Qinba mountainous area in southern Shaanxi is more sensitive to various disasters caused by extreme precipitation. Relevant research can strengthen the regional extreme precipitation forecast and mountain disaster forecast,and guide the formulation of adaptive governance plans. Based on the daily precipitation data of 19 gauge stations from 1998 to 2016,the percentile threshold 95 was used for selection extreme precipitation,and the spatial variation characteristics of extreme precipitation were analyzed. The results show that the number of extreme precipitations in Qinba mountains of southern Shaanxi decreases from south to north,and the mountain flood and debris flow disasters caused by short-time extreme precipitation;the extreme precipitation’s mean value and variation coefficient contour are consistent with the direction of the Han River;Zhenping and Foping counties need to conduct key disaster prevention design. The research enriches the meteorological data in Qinba mountainous areas,and also provides a scientific basis for the prediction of regional extreme precipitation and mountain disasters.