The exceptional flood of July 2021 in central Europe impacted Belgium severely. This study aims to characterize rainfall amounts in Belgium from 13 to 16 July 2021 based on observational data (i.e., rain gauge data and a radar-based rainfall product). The spatial and temporal distributions of rainfall during the event aredescribed. In order to document such a record-breaking event as much as possible, the rainfall data are shared with the scientific community on Zenodo for further studies.

The current research investigated, as a representative study case, the sediment accumulated in the Poechos Reservoir (located on the west coast of northern Peru) for retrospectively reconstructing the impact on sediment dynamics (1978–2019) of extreme phases of the El Niño–Southern Oscillation, land cover changes after humid periods and agricultural expansion along the riverine system.

The Priestley–Taylor equation is widely used in hydrologic, climate, and meteorological models to estimate evaporation. α represents the impact of dry air that is carried into the region; this occurs even in extensive saturated regions. Four hypotheses regarding the nature of α are evaluated. Data from 171 FLUXNET stations were used to test the hypotheses. The best-supported hypothesis sees α as a constant fraction of the distance between theoretical minimum and maximum values.

We propose a model calibration method constraining groundwater seepage in the hydrographic network. The method assesses the hydraulic properties of aquifers in regions where perennial streams are directly fed by groundwater. The estimated hydraulic conductivity appear to be highly sensitive to the spatial extent and density of streams. Such an approach improving subsurface characterization from surface information is particularly interesting for ungauged basins.

The computational cost of sensitivity analysis (SA) becomes prohibitive for large hydrologic modeling domains. Here, using a large-scale Variable Infiltration Capacity (VIC) deployment, we show that watershed classification helps identify the spatial pattern of parameter sensitivity within the domain at a reduced cost. Findings reveal the opportunity to leverage climate and land cover attributes to reduce the cost of SA and facilitate more rapid deployment of large-scale land surface models.

We compared hourly data from precipitation gauges with lysimeter reference data at three sites under different climatic conditions. Our results show that precipitation gauges recorded 33–96 % of the reference precipitation data for the period under consideration (2015–2018). Correction algorithms increased the registered precipitation by 9–14 %. It follows that when using point precipitation data, regardless of the precipitation measurement method used, relevant uncertainties must be considered.

Teaching hydrological modeling is an important, but difficult, matter. It requires appropriate tools and teaching material. In this article, we present the airGRteaching package, which is an open-source software tool relying on widely used hydrological models. This tool proposes an interface and numerous hydrological modeling exercises representing a wide range of hydrological applications. We show how this tool can be applied to simple but real-life cases.