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This study presents a coupled application of hydrological and hydraulic models to reconstruct a flash flood event of the ungauged watercourse of Wadi Deffa, Algeria. The objective is to compare the performances of three hydrological models (rational method, EBA4SUB, HEC-HMS) and two hydraulic bidimensional models (HEC-RAS 2D, FLO-2D) by using the Volunteered Geographic Information (VGI) data. The comparison between the observed and simulated flood areas showed satisfactorily performance of the EBA4SUB-FLO-2D approach compared to the other approaches. The analysis of the observed and simulated flood depths showed a good estimate using the approaches EBA4SUB-FLO-2D and EBA4SUB-HEC- RAS 2D. The best estimate of the two flood depth approaches is attributed to the hydrological model EBA4SUB in estimating the peak flow. The results demonstrate that the EBA4SUB-FLO-2D modeling approach can provide reliable data for the management of flood risks in the ungauged watersheds of the southwest region of Algeria. [ABSTRACT FROM AUTHOR]

Of all the substances that can be present in water intended for human consumption, arsenic (As) is one of the most toxic. Many treatment technologies can be used for removing As from water, for instance, adsorption onto iron media, where commercially available adsorbents are removed and replaced with new media when they are exhausted. Since this is an expensive operation, in this work, a novel and portable plant for regenerating iron media has been developed and tested in four real case studies in Central Italy. The obtained results highlight the good efficiency of the system, which was able, from 2019 to 2023, to regenerate the iron media and to restore its capability to adsorb the As from water almost entirely. Indeed, when the legal threshold value of 10 μg/L is exceeded, the regeneration process is performed and, after that, the As concentration in the water effluent is at the minimum level in all the investigated case studies. [ABSTRACT FROM AUTHOR]

Flood quantile estimation in ungauged basins is often performed using regional analysis. A regionalization procedure consists of two phases: the definition of homogeneous regions among gauged basins, i.e., clusters of stations, and information transfer to the ungauged sites. Due to its simplicity and widespread use, a combination of hierarchical clustering by Ward's algorithm and the index-flood method is applied in this research. While hierarchical clustering is very efficient, its shortcomings are the lack of flexibility in the definition of clusters/regions and the inability to transfer objects/stations from one cluster center to another. To overcome this, using silhouette width for induced clustering of stations in flood studies is proposed in this paper. A regionalization procedure is conducted on 53 gauging stations under a continental climate in the West Balkans. In the induced clustering, a negative silhouette width is used as an indicator for the relocation of station(s) to another cluster. The estimates of mean annual flood and 100-year flood quantiles assessed by the original and induced clustering are compared. A jackknife procedure is applied for mean annual flood estimation and 100-year flood quantiles. Both the Hosking–Wallis and Anderson–Darling bootstrap tests provide better results regarding the homogeneity of the defined regions for the induced clustering compared to the original one. The goodness-of-fit measures indicate improved clustering results by the proposed intervention, reflecting flood quantile estimation at the stations with significant overestimation by the original clustering. [ABSTRACT FROM AUTHOR]