Large-Scale Hydrological Simulations Using the Soil Water Assessment Tool, Protocol Development, and Application in the Danube Basin

Abstract

The Water Framework Directive of the European Union requires member states to achieve good ecological status of all water bodies. A harmonized pan-European assessment of water resources availability and quality, as affected by various management options, is necessary for a successful implementation of European environmental legislation. In this context, we developed a methodology to predict surface water flow at the pan-European scale using available datasets. Among the hydrological models available, the Soil Water Assessment Tool was selected because its characteristics make it suitable for large-scale applications with limited data requirements. This paper presents the results for the Danube pilot basin. The Danube Basin is one of the largest European watersheds, covering approximately 803,000 km 2 and portions of 14 countries. The modeling data used included land use and management information, a detailed soil parameters map, and high-resolution climate data. The Danube Basin was divided into 4663 subwatersheds of an average size of 179 km 2 . A modeling protocol is proposed to cope with the problems of hydrological regionalization from gauged to ungauged watersheds and overparameterization and identifiability, which are usually present during calibration. The protocol involves a cluster analysis for the determination of hydrological regions and multiobjective calibration using a combination of manual and automated calibration. The proposed protocol was successfully implemented, with the modeled discharges capturing well the overall hydrological behavior of the basin.

Comparison of three regionalization techniques for predicting streamflow in ungaged watersheds in Nebraska, USA using SWAT model

“…In another study using the SWAT model, Pagliero et al [14] proposed a protocol with the objective of overcoming model calibration by using regional parameterization of the model and improving calibration transparency for overcoming identifiability problems. They applied SWAT to the 803 000 km 2 Danube River Basin (DRB) in Europe, delineated the basin at high resolution into 4663 subbasins, and implemented a regional calibration by relating hydrologic responses to watershed properties using a partial least squares regression analysis.…”

“…They selected gaged watersheds that are representative of each region of the DRB and performed calibrations of selected watersheds to obtain a set of calibrated parameters that are representative of every hydrological region in the basin. Pagliero et al [14] then extrapolated a set of calibrated parameters to a corresponding region with the DRB. For four calibration and three validation regions, they reported monthly streamflow NSE values ranging from 0.65 to 0.75 and from 0.28 to 0.66, respectively.…”

“…Daggupati et al [15] followed a protocol similar to Pagliero et al [14] and simulated water and crop yields in one of the few reported model simulation investigations of the entire Missouri River Basins (MRB) located in the north central portion of the U.S. After obtaining satisfactory results from flow calibration at the head watersheds in their delineated project, they used a regionalization calibration approach to transfer the calibration parameter set from each head watershed was to the subwatersheds within eleven MRB regions. Daggupati et al [15] reported that observed and simulated water yields in the head watersheds and those in the validation locations were in close agreement for naturalized stream systems within the MRB.…”

Challenges in modelling of water quantity and quality in two contrasting meso-scale catchments in Poland

“…One of the most popular models is Soil and Water Assessment Tool (SWAT) which was applied in Europe across a range of spatial scales: from the whole continent , to largest river basins [ČERKASOVA et al 2016;PAGLIERO et al 2014;PI-NIEWSKI et al 2016], meso-scale catchments [OSTOJ-SKI et al 2014;PINIEWSKI et al 2015] and small catchments [BRZOZOWSKI et al 2011;MARCINKOW-SKI et al 2013;MOLINA-NAVARRO et al 2014; SMA-RZYŃSKA, MIATKOWSKI 2016;ŚMIETANKA 2014]. An increasing interest in the model triggers more com-plex and challenging applications, especially concerning implementation of new remote sensing techniques and datasets [AL-DOUSARI et al 2010] or more detailed multi-site and multi-variable calibration approach [WOZNICKI et al 2016].…”

Natural streamflow simulation for two largest river basins in Poland: a baseline for identification of flow alterations

“…To date, the VOB has not been modelled in a comparable manner as the remaining three basins from the EU's top five: the Danube (Pagliero et al, 2014), the Rhine or the Elbe (Huang et al, 2015). The VOB is covered by larger-scale applications, e.g.…”