An evaluation of automated GPD threshold selection methods for hydrological extremes across different scales

JOURNAL OF HYDROLOGY

卷:585

Article

Curceac, Stelian¹  Atkinson, Peter M.^2,3,4,5  Milne, Alice⁶  Wu, Lianhai¹  Harris, Paul¹ 

[1] Rothamsted Res, Dept Sustainable Agr Sci, North Wyke EX20 2SB, Devon, England

[2] Univ Lancaster, Lancaster Environm Ctr, Lancaster LA1 4YQ, England

[3] Univ Southampton, Geog & Environm, Southampton SO17 1BJ, Hants, England

[4] Queens Univ Belfast, Sch Geog Archaeol & Palaeoecol, Belfast BT7 1NN, Antrim, North Ireland

[5] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, State Key Lab Resources & Environm Informat Syst, Beijing 100101, Peoples R China

[6] Rothamsted Res, Dept Sustainable Agr Sci, Harpenden AL5 2JQ, Herts, England

关键词: Generalized pareto distribution;    Peaks over threshold;    Threshold selection;    Flood frequency analysis;    Scale effects;    Grassland agriculture;   

DOI  :  10.1016/j.jhydrol.2020.124845

来源: Elsevier

【 摘 要 】

This study investigated core components of an extreme value methodology for the estimation of high-flow frequencies from agricultural surface water run-off. The Generalized Pareto distribution (GPD) was used to model excesses in time-series data that resulted from the 'Peaks Over Threshold' (POT) method. First, the performance of eight different GPD parameter estimators was evaluated through a Monte Carlo experiment. Second, building on the estimator comparison, two existing automated GPD threshold selection methods were evaluated against a proposed approach that automates the threshold stability plots. For this second experiment, methods were applied to discharge measured at a highly-instrumented agricultural research facility in the UK. By averaging fine-resolution 15-minute data to hourly, 6-hourly and daily scales, we were also able to determine the effect of scale on threshold selection, as well as the performance of each method. The results demonstrate the advantages of the proposed threshold selection method over two commonly applied methods, while at the same time providing useful insights into the effect of the choice of the scale of measurement on threshold selection. The results can be generalised to similar water monitoring schemes and are important for improved characterisations of flood events and the design of associated disaster management protocols.

【 授权许可】

Free