Identifying Extreme Rainfall Events Using Functional Outliers Detection Methods

• 作者: Mohanned Abduljabbar Hael Yongsheng Yuan
• 来源期刊: 数据分析和信息处理(英文)
• 学科: 地球科学
• 关键词: Rainfall Data Outlier Detection Rainbow Plot Functional Bag-Plot Functional Box-Plot
• 年，卷（期）: 2020,（4）
• 页码范围: 282-294
• 页数: 13页
• 分类号: P73

摘要

Outlier detection techniques play a vital role in exploring unusual data of extreme events that have a critical effect considerably in the modeling and forecasting of functional data. The functional methods have an effective way of identifying outliers graphically, which might not be visible through the original data plot in classical analysis. This study’s main objective is to detect the extreme rainfall events using functional outliers detection methods depending on the depth and density functions. In order to identify the unusual events of rainfall variation over long time intervals, this work conducts based on the average monthly rainfall of the Taiz region from 1998 to 2019. Data were extracted from the Tropical Rainfall Measuring Mission and the analysis has been processed by R software. The approaches applied in this study involve rainbow plots, functional highest density region box-plot as well as functional bag-plot. According to the current results, the functional density box-plot method has proven effective in detecting outlier compared to the functional depth bag-plot method. In conclusion, the results of the current study showed that the rainfall over the Taiz region during the last two decades was influenced by the extreme events of years 1999, 2004, 2005, and 2009.