DOI: 10.1007/s11069-021-04775-w
论文题名: Evaluation of the similarity between drought indices by correlation analysis and Cohen's Kappa test in a Mediterranean area
作者: Vergni L. ; Todisco F. ; Di Lena B.
刊名: Natural Hazards
ISSN: 0921030X
出版年: 2021
卷: 108, 期: 2 起始页码: 2187
结束页码: 2209
语种: 英语
中文关键词: Effective Drought Index
; Extreme events
; Precipitation
; Rainfall Anomaly Index
; Standardised Precipitation Index
英文关键词: correlation
; drought
; extreme event
; precipitation assessment
; precipitation intensity
; time series analysis
; Mediterranean Sea
英文摘要: In the literature, numerous papers report comparative analyses of drought indices. In these types of studies, the similarity between drought indices is usually evaluated using the Pearson correlation coefficient, r, calculated between corresponding severity time series. However, it is well known that the correlation does not describe the strength of agreement between two variables. Two drought indices can exhibit a high degree of correlation but can, at the same time, disagree substantially, for example, if one index is consistently higher than the other. From an operational point of view, two indices can be considered in agreement when they indicate the same severity category for a given period (e.g. moderate drought). In this work, we compared six meteorological drought indices based on both correlation analysis and Cohen's Kappa test. This test is typically used in medical or social sciences to obtain a quantitative assessment of the degree of agreement between different methods or analysts. The indices considered are five timescale-dependent indices, i.e. the Percent of Normal Index, the Deciles Index, the Percentile Index, the Rainfall Anomaly Index, and the Standardised Precipitation Index, computed at the 1-, 3-, and 6-month timescales, and the Effective Drought Index, a relatively new index, which has a self-defined timescale. The indices were calculated for 15 stations in the Abruzzo region (central Italy) during 1951–2018. We found that the strength of agreement depends on both the criteria of drought severity classification and the different indices' calculation method. The Cohen's Kappa test indicates a prevailing moderate or fair agreement among the indices considered, despite the generally very high correlation between the corresponding severity times series. The results demonstrate that the Cohen's Kappa test is more effective than the correlation analysis in discriminating the actual strength of agreement/disagreement between drought indices. © 2021, The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/169425
Appears in Collections: 气候变化与战略
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作者单位: Department of Agricultural, Food and Environmental Sciences, University of Perugia, Borgo XX Giugno 74, Perugia, 06121, Italy; Abruzzo Region – Agriculture Directorate- Regional Agro-Meteorological Centre, Scerni, CH, Italy
Recommended Citation:
Vergni L.,Todisco F.,Di Lena B.. Evaluation of the similarity between drought indices by correlation analysis and Cohen's Kappa test in a Mediterranean area[J]. Natural Hazards,2021-01-01,108(2)