Regional Flood Frequency Analysis of the Sava River in South-Eastern Europe

Journal: Sustainability

Abstract: Regional flood frequency analysis (RFFA) is a powerful method for interrogating hydrological series since it combines observational time series from several sites within a region to estimate risk-relevant statistical parameters with higher accuracy than from single-site series. Since RFFA extreme value estimates depend on the shape of the selected distribution of the data-generating stochastic process, there is need for a suitable goodness-of-distributional-fit measure in order to optimally utilize given data. Here we present a novel, least-squares-based measure to select the optimal fit from a set of five distributions, namely Generalized Extreme Value (GEV), Generalized Logistic, Gumbel, Log-Normal Type III and Log-Pearson Type III. The fit metric is applied to annual maximum discharge series from six hydrological stations along the Sava River in South-eastern Europe, spanning the years 1961 to 2020. Results reveal that (1) the Sava River basin can be assessed as hydrologically homogeneous and (2) the GEV distribution provides typically the best fit. We offer hydrological‒meteorological insights into the differences among the six stations. For the period studied, almost all stations exhibit statistically insignificant trends, which renders the conclusions about flood risk as relevant for hydrological sciences and the design of regional flood protection infrastructure.

URL: https://www.mdpi.com/2071-1050/14/15/9282

The uploaded datasets are the Annual Maximum Series of Sava River runoff for the six analysed hydrological stations: Radovljica, Čatež, Zagreb, Jasenovac, Županja and S. Mitrovica.

期刊：《Sustainability》

摘要：区域洪水频率分析（Regional Flood Frequency Analysis, RFFA）是研究水文序列的有效方法，其通过整合区域内多个站点的观测时间序列，可估算与风险相关的统计参数，精度高于单站点序列分析。由于RFFA的极值估计结果依赖于数据生成随机过程所选定的分布形态，因此需要合适的分布拟合优度指标，以最优地利用现有数据。本文提出一种基于最小二乘法的新型拟合指标，可从五种分布（即广义极值分布（Generalized Extreme Value, GEV）、广义逻辑分布、耿贝尔分布、Ⅲ型对数正态分布以及Ⅲ型对数皮尔逊分布）中选出最优拟合分布。该拟合指标被应用于欧洲东南部萨瓦河沿岸6个水文站的年最大流量序列，时间跨度为1961年至2020年。研究结果表明：（1）萨瓦河流域可被认定为水文均质流域；（2）广义极值分布（GEV）通常能提供最优拟合效果。本文还对6个水文站之间的差异进行了水文-气象学层面的解析。在所研究的时段内，几乎所有站点的趋势均无统计学显著性，这使得本研究关于洪水风险的结论对水文科学研究以及区域防洪基础设施设计均具有参考价值。

URL：https://www.mdpi.com/2071-1050/14/15/9282

本次上传的数据集为本次分析涉及的6个水文站的萨瓦河径流年最大序列，分别为拉德沃尔比察（Radovljica）、察泰什（Čatež）、萨格勒布（Zagreb）、亚塞诺瓦茨（Jasenovac）、茹帕尼亚（Županja）以及斯梅代雷沃米特罗维察（S. Mitrovica）。