基于K-means雨型分类方法的温州市台风暴雨时空演变特征研究

K-means classification method of rain pattern-based study on spatio-temporal evolution characteristics of typhoon rainstorm in wenzhou

伴随全球气候变暖,暴雨事件的频次与强度呈增强趋势,对于暴雨时空演变规律的研究对区域防洪减灾和水资源管理具有重要意义。基于1960—2018年日尺度降雨数据和1980—2017年台风过境期间的小时尺度降雨数据对温州市的暴雨特征时空演变规律进行分析,使用的分析方法包括去趋势预置白的Mann-Kendall趋势检验、基于K-means聚类算法的雨型分析等。日尺度暴雨指标的趋势和突变检验结果显示,暴雨指标受到地形和地理位置影响较大。小时尺度降雨数据的暴雨指标表明,台风暴雨指标随下垫面特征和地形特征不同而呈现不同的特征和变化趋势;山区地区的降雨总量和持续时间的上升趋势高于平原地区。小时尺度暴雨雨型分析表明,温州市暴雨雨型以单峰型为主,单峰中期型占比最大。研究成果有助于加深对该区域暴雨时空演变规律的认识,为区域防洪减灾和水资源管理提供参考。

With global warming,the frequency and intensity of rainstorm events are increasing,which is of great significance to the study of the evolution regularity of rainstorm time and space for regional flood prevention and water resources management.Based on the daily scale rainfall data from 1960 to 2018 and the hourly scale rainfall data during the typhoon transit period from 1980 to 2017 in Wenzhou,the spatio-temporal evolution law of rainstorm characteristics is analyzed herein;for which the analysis methods include Mann-Kendall test with trend-free pre-whitening method,K-means clustering algorithm-based rainfall pattern analysis,etc.The trend and the mutation test result of the daily scale rainstorm index show that the rainstorm index is largely affected by both landform and geographical location.The rainstorm index of hourly scale rainfall data shows that the typhoon rainstorm index exhibits different characteristics and changing trends for different underlying surface characteristics and landform characteristics,while the rising trends of both the total rainfall and the duration in mountainous region are higher than those in plain region.The analysis of the hourly scale rainstorm pattern shows that the main rainstorm patterns in Wenzhou are the single-peak patterns with the largest proportion of the pattern of single-peak mid-term.The study results are helpful to deepen the understanding of the spatio-temporal evolution law of the rainstorm in this region,and then provide some references for both the flood control and disaster reduction and water resources management within the region.