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Hydrological models can benefit from soft calibration, a process by which the proper simulation of hydrological variables is proved while or before addressing hard calibration. Soft calibration reduces the probability of obtaining a statistically accurate but unrealistic model. However, it requires soft data, which is often hard to acquire or unavailable. This work presents HydRoVars, an R tool developed to facilitate the estimation of data which can be implemented in a soft calibration procedure. It allows to estimate two key hydrological indices (the runoff coefficient and the baseflow index) and weather-related variables at the catchment scale for one or numerous basins. The runoff coefficient is calculated automatically from precipitation and streamflow datasets. Groundwater contribution is estimated through a semi-automatic process based on a baseflow filter which considers hydrogeological properties. Modellers would benefit from incorporating soft calibration in their calibration procedures, and this tool might help to estimate these relevant hydrological variables in their modelled area. The tool has been tested in 19 subbasins of the Tagus River basin (Spain) located in different geological regions. In the test cases, we demonstrate the usefulness of this tool to improve the model representation and gain an understanding of the catchments' hydrology.

The soil and water assessment tool (SWAT) model was applied for the first time in Cuba to assess the potential impacts of climate change on water availability in the Cauto River basin. The model was calibrated (and validated) for the 2001–2006 (2007–2010) period at a monthly timescale in two subbasins La Fuente and Las Coloradas, representative of middle and upper sections of the Cauto basin; the calibrated models showed good performance. The output available for the regional climate Model RegCM4.3 was used to force the calibrated SWAT models to simulate a baseline (1970–2000) period and near-future (2015–2039) hydrologic regimes under the representative concentration pathway (RCP) 8.5 emission scenario. The future projections suggest regional increases of 1.5 °C in mean annual temperature and a 38% decrease in mean annual precipitation in the subbasins. These changes translate to possible reductions in the annual streamflow of up to 61% with respect to the baseline period, whereas the aquifer recharge in the basin is expected to decrease up to 58%, with a consequent reduction of groundwater flow, especially during the boreal summer wet season. These projection scenarios should be of interest to water resources managers in tropical regions.

The soil and water assessment tool (SWAT) model was applied for the first time in Cuba to assess the potential impacts of climate change on water availability in the Cauto River basin. The model was calibrated (and validated) for the 2001–2006 (2007–2010) period at a monthly timescale in two subbasins La Fuente and Las Coloradas, representative of middle and upper sections of the Cauto basin; the calibrated models showed good performance. The output available for the regional climate Model RegCM4.3 was used to force the calibrated SWAT models to simulate a baseline (1970–2000) period and near-future (2015–2039) hydrologic regimes under the representative concentration pathway (RCP) 8.5 emission scenario. The future projections suggest regional increases of 1.5 °C in mean annual temperature and a 38% decrease in mean annual precipitation in the subbasins. These changes translate to possible reductions in the annual streamflow of up to 61% with respect to the baseline period, whereas the aquifer recharge in the basin is expected to decrease up to 58%, with a consequent reduction of groundwater flow, especially during the boreal summer wet season. These projection scenarios should be of interest to water resources managers in tropical regions.

Predicting the sediment yield at a catchment scale is one of the main challenges regarding fluvial geomorphology, however, it involves some difficulties. In this study, we have taken advantage of the construction of a new hydraulic infrastructure to study the sediment yield in its drainage basin between 2007 and 2010. This infrastructure is a small dam constructed in the riverine zone of the Entrepeñas Reservoir (upper Tagus catchment, central Spain), which generates a small water body, the Pareja Limno-reservoir (0.94 hm3), with a drainage area of 88 km2. It was built to mitigate the environmental and socioeconomic impacts of the construction and use of the Entrepeñas Reservoir, including the “arid band” phenomenon.Sediment yield was studied taking three sediment cores in the shallowest section, the central part and the deepest zone of the limno-reservoir. The layer of surface sediment was analized and a decreasing thickness of sediment towards the deepest zone of the limno-reservoir was observed. After assigning an area of the limno-reservoir to each core record, estimated annual sedimentation rate was 2032 Mg year-1, which supposes an annual storage capacity loss around 0.3% and a specific sediment yield in the drainage basin around 0.23 Mg ha-1 year-1. Comparing this value with previous soil loss studies performed in the basin, sediment delivery ratio in the basin varies from 2.2% to 3.8%.Both sediment yield and sediment delivery ratio showed low values for the Mediterranean context. The characteristics of the basin (small area, elongated shape with one main river channel, abundant vegetation), the absence of other erosive processes than rill and interrill erosion and the lower aggressiveness of rainfall in the center of the Iberian Peninsula may explain these results. The presence of the National Road N-204 surrounding the limno-reservoir may play a role in the low sediment delivery, especially from the adjoining hillslopes., En geomorfología fluvial, la estimación de la producción de sedimentos a escala de cuenca es uno de los grandes retos, aunque no exento de dificultades. En este estudio se ha aprovechado la oportunidad que brinda la construcción de una nueva infraestructura hidráulica para estudiar la producción de sedimentos en su cuenca vertiente entre 2007 y 2010. Se trata de un dique construido en una zona de cola del embalse de Entrepeñas (cuenca alta del Tajo), el cual genera una pequeña masa de agua, el limnoembalse de Pareja (de 0.94 hm3 y con una cuenca vertiente de 88 km2). Su objetivo es mitigar los impactos ambientales y socioeconómicos generados por la construcción y explotación del embalse de Entrepeñas, incluido el fenómeno de “banda árida”.La producción de sedimentos fue estudiada mediante la toma de tres testigos de sondeo, uno en la zona más superficial, otro en el sector intermedio del limno-embalse y el último en la zona más profunda. Se analizó la capa de sedimento superficial y se observó una reducción del su espesor hacia la zona de presa. Se asignó un sector del limno-embalse a cada testigo y se estimó una tasa de sedimentación anual de 2032 Mg año-1, lo que supone una pérdida anual de volumen en torno al 0.3% y una producción específica de sedimentos aproximada en la cuenca de 0.23 Mg ha-1 año-1. Comparando estos valores con estudios de erosión de suelo que se han llevado a cabo en la cuenca con anterioridad, la tasa de suministro de sedimentos en la cuenca oscila entre un 2.2% y un 3.8%.En comparación con los valores habituales en el contexto mediterráneo, tanto la producción de sedimentos como el porcentaje de los mismos que alcanza el limnoembalse muestran valores bajos. Ello puede deberse a las características de la cuenca (área pequeña, forma alargada con un río principal, abundante vegetación), la ausencia de otros tipos de erosión aparte de la erosión laminar y en regueros y la menor agresividad de la lluvia en el centro de la Península Ibérica. Ademá

Predicting the sediment yield at a catchment scale is one of the main challenges regarding fluvial geomorphology, however, it involves some difficulties. In this study, we have taken advantage of the construction of a new hydraulic infrastructure to study the sediment yield in its drainage basin between 2007 and 2010. This infrastructure is a small dam constructed in the riverine zone of the Entrepeñas Reservoir (upper Tagus catchment, central Spain), which generates a small water body, the Pareja Limno-reservoir (0.94 hm3), with a drainage area of 88 km2. It was built to mitigate the environmental and socioeconomic impacts of the construction and use of the Entrepeñas Reservoir, including the “arid band” phenomenon.Sediment yield was studied taking three sediment cores in the shallowest section, the central part and the deepest zone of the limno-reservoir. The layer of surface sediment was analized and a decreasing thickness of sediment towards the deepest zone of the limno-reservoir was observed. After assigning an area of the limno-reservoir to each core record, estimated annual sedimentation rate was 2032 Mg year-1, which supposes an annual storage capacity loss around 0.3% and a specific sediment yield in the drainage basin around 0.23 Mg ha-1 year-1. Comparing this value with previous soil loss studies performed in the basin, sediment delivery ratio in the basin varies from 2.2% to 3.8%.Both sediment yield and sediment delivery ratio showed low values for the Mediterranean context. The characteristics of the basin (small area, elongated shape with one main river channel, abundant vegetation), the absence of other erosive processes than rill and interrill erosion and the lower aggressiveness of rainfall in the center of the Iberian Peninsula may explain these results. The presence of the National Road N-204 surrounding the limno-reservoir may play a role in the low sediment delivery, especially from the adjoining hillslopes., En geomorfología fluvial, la estimación de la producción de sedimentos a escala de cuenca es uno de los grandes retos, aunque no exento de dificultades. En este estudio se ha aprovechado la oportunidad que brinda la construcción de una nueva infraestructura hidráulica para estudiar la producción de sedimentos en su cuenca vertiente entre 2007 y 2010. Se trata de un dique construido en una zona de cola del embalse de Entrepeñas (cuenca alta del Tajo), el cual genera una pequeña masa de agua, el limnoembalse de Pareja (de 0.94 hm3 y con una cuenca vertiente de 88 km2). Su objetivo es mitigar los impactos ambientales y socioeconómicos generados por la construcción y explotación del embalse de Entrepeñas, incluido el fenómeno de “banda árida”.La producción de sedimentos fue estudiada mediante la toma de tres testigos de sondeo, uno en la zona más superficial, otro en el sector intermedio del limno-embalse y el último en la zona más profunda. Se analizó la capa de sedimento superficial y se observó una reducción del su espesor hacia la zona de presa. Se asignó un sector del limno-embalse a cada testigo y se estimó una tasa de sedimentación anual de 2032 Mg año-1, lo que supone una pérdida anual de volumen en torno al 0.3% y una producción específica de sedimentos aproximada en la cuenca de 0.23 Mg ha-1 año-1. Comparando estos valores con estudios de erosión de suelo que se han llevado a cabo en la cuenca con anterioridad, la tasa de suministro de sedimentos en la cuenca oscila entre un 2.2% y un 3.8%.En comparación con los valores habituales en el contexto mediterráneo, tanto la producción de sedimentos como el porcentaje de los mismos que alcanza el limnoembalse muestran valores bajos. Ello puede deberse a las características de la cuenca (área pequeña, forma alargada con un río principal, abundante vegetación), la ausencia de otros tipos de erosión aparte de la erosión laminar y en regueros y la menor agresividad de la lluvia en el centro de la Península Ibérica. Ademá