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Alvaro Sordo-Ward  - - - 
Top co-authors See all
Luis Garrote

103 shared publications

Department of Civil Engineering: Hydraulics, Energy and Environment, Universidad Politécnica de Madrid, 28040 Madrid, Spain

Ana Iglesias

57 shared publications

Department of Agricultural Economics & CEIGRAM, Universidad Politécnica de Madrid, Madrid 28040, Spain

Luis Mediero

30 shared publications

Department of Civil Engineering: Hydraulic, Energy and Environment, Technical University of Madrid, Madrid, Spain

Alfredo Granados

10 shared publications

Universidad Politécnica de Madrid; Madrid Spain

Paola Bianucci

7 shared publications

AQUATEC (Suez Group); Dep. Basin Management; Madrid Spain

Publication Record
Distribution of Articles published per year 
(2015 - 2019)
Total number of journals
published in
Publications See all
Article 0 Reads 0 Citations Hydrological Risk Analysis of Dams: The Influence of Initial Reservoir Level Conditions Ivan Gabriel-Martin, Alvaro Sordo-Ward, Luis Garrote, Isabel... Published: 05 March 2019
Water, doi: 10.3390/w11030461
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In this paper, we present a method to assess the influence of the initial reservoir level in hydrological dam safety and risk analysis. Traditionally, in professional practice, the procedures applied are basically deterministic. Several physical processes are defined deterministically, according to the criteria of the designer (usually in the conservative side), although there is a high degree of uncertainty regarding these processes. A relevant variable is the reservoir level considered at the beginning of flood events. Hydrological dam safety assessment methods traditionally assume that the reservoir is initially full when it receives the design flood, thus, staying in the conservative side when designing a new dam. However, the distribution of reservoir levels at the beginning of flood episodes takes more importance for evaluating the real risk for the dams in operation. We analyzed three different scenarios—initial reservoir level equal to maximum normal level, equal to a maximum conservation level, and following the probability distribution from the historical records. To do so, we presented a method applied to a gated-spillway dam located in the Tagus river basin. A set of 100,000 inflow hydrographs was generated through a Monte Carlo procedure, by reproducing the statistics of the main observed hydrograph characteristics—peak flow, volume, and duration. The set of 100,000 hydrographs was routed through the reservoir applying the Volumetric Evaluation Method as a flood control strategy. In order to compare the three scenarios, we applied an economic global risk index. The index combines the hydrological risk for the dam, linked to the maximum water level reached in the reservoir, during the flood routing, and the flood risk in the downstream river reach, linked to the discharge releases from the dam. The results showed the importance of accounting for the fluctuation of initial reservoir levels, for assessing the risk related to hydrological dam safety. Furthermore, a procedure to quantify the uncertainty associated with the effects of initial reservoir level on hydrological dam safety, has been proposed.
Article 0 Reads 0 Citations Blue Water in Europe: Estimates of Current and Future Availability and Analysis of Uncertainty Alvaro Sordo-Ward, Isabel Granados, Ana Iglesias, Luis Garro... Published: 26 February 2019
Water, doi: 10.3390/w11030420
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This study presents a regional assessment of future blue water availability in Europe under different assumptions. The baseline period (1960 to 1999) is compared to the near future (2020 to 2059) and the long-term future (2060 to 2099). Blue water availability is estimated as the maximum amount of water supplied at a certain point of the river network that satisfies a defined demand, taking into account specified reliability requirements. Water availability is computed with the geospatial high-resolution Water Availability and Adaptation Policy Assessment (WAAPA) model. The WAAPA model definition for this study extends over 6 million km2 in Europe and considers almost 4000 sub-basins in Europe. The model takes into account 2300 reservoirs larger than 5 hm3, and the dataset of Hydro 1k with 1700 sub-basins. Hydrological scenarios for this study were taken from the Inter-Sectoral Impact Model Inter-Comparison Project and included simulations of five global climate models under different Representative Concentration Pathways scenarios. The choice of method is useful for evaluating large area regional studies that include high resolution on the systems´ characterization. The results highlight large uncertainties associated with a set of local water availability estimates across Europe. Climate model uncertainties for mean annual runoff and potential water availability were found to be higher than scenario uncertainties. Furthermore, the existing hydraulic infrastructure and its management have played an important role by decoupling water availability from hydrologic variability. This is observed for all climate models, the emissions scenarios considered, and for near and long-term future. The balance between water availability and withdrawals is threatened in some regions, such as the Mediterranean region. The results of this study contribute to defining potential challenges in water resource systems and regional risk areas.
Article 5 Reads 3 Citations Analysis of Current and Future SPEI Droughts in the La Plata Basin Based on Results from the Regional Eta Climate Model Alvaro Sordo-Ward, María Dolores Bejarano, Ana Iglesias, Víc... Published: 04 November 2017
Water, doi: 10.3390/w9110857
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We identified and analysed droughts in the La Plata Basin (divided into seven sub-basins) for the current period (1961–2005) and estimated their expected evolution under future climate projections for the periods 2011–2040, 2041–2070, and 2071–2099. Future climate projections were analysed from results of the Eta Regional Climate Model (grid resolution of approximately 10 km) forced by the global climate model HadGEM2-ES over the La Plata basin, and considering a RCP4.5 emission scenario. Within each sub-basin, we particularly focused our drought analyses on croplands and grasslands, due to their economic relevance. The three-month Standardized Precipitation Evapotranspiration Index (SPEI3) was used for drought identification and characterization. Droughts were evaluated in terms of time (percentage of time from the total length of each climate scenario), space (percentage of total area), and severity (SPEI3 values) of cells characterized by cropland and grassland for each sub-basin and climate scenario. Drought-severity–area–frequency curves were developed to quantitatively relate the frequency distribution of drought occurrence to drought severity and area. For the period 2011–2040, droughts dominate the northern sub-basins, whereas alternating wet and short dry periods dominate the southern sub-basins. Wet climate spread from south to north within the La Plata Basin as more distant future scenarios were analysed, due to both a greater number of wet periods and fewer droughts. The area of each sub-basin affected by drought in all climate scenarios was highly varied temporally and spatially. The likelihood of the occurrence of droughts differed significantly between the studied cover types in the Lower Paraguay sub-basin, being higher for cropland than for grassland. Mainly in the Upper Paraguay and in the Upper Paraná basins the climate projections for all scenarios showed an increase of moderate and severe droughts over large regions dedicated to crops and grasses. On the other hand, for the near future, the Lower Uruguay and the River Plata basins showed a decrease of drought severity compared to the current period. Projections suggest an increase in competition among uses in these regions and the need for a potential relocation of certain crops from the northern regions towards cooler regions located in the centre and south. Further research should consider other climate projections and perform high spatial resolution studies in localized areas.
Article 5 Reads 4 Citations A Parametric Flood Control Method for Dams with Gate-Controlled Spillways Alvaro Sordo-Ward, Ivan Gabriel-Martin, Paola Bianucci, Luis... Published: 28 March 2017
Water, doi: 10.3390/w9040237
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The study presents a method which can be used to define real-time operation rules for gated spillways (named the K-Method). The K-Method is defined to improve the performance of the Volumetric Evaluation Method (VEM), by adapting it to the particular conditions of the basin, the reservoir, or the spillway. The VEM was proposed by the Spanish engineer Fernando Girón in 1988 and is largely used for the specification of dam management rules during floods in Spain. This method states that outflows are lower than or equal to antecedent inflows, outflows increase when inflows increase, and the higher the reservoir level, the higher the percentage of outflow increase. The K-Method was developed by modifying the VEM and by including a K parameter which affects the released flows. A Monte Carlo environment was developed to evaluate the method under a wide range of inflow conditions (100,000 hydrographs) and with return periods ranging from one to 10,000 years. The methodology was applied to the Talave reservoir, located in the South-East of Spain. The results show that K-values higher than one always reduce the maximum reservoir levels reached in the dam. For K-values ranging from one to ten, and for inflow hydrographs with return periods higher than 100 years, we found a decrease in the maximum levels and outflows, when compared to the VEM. Finally, by carrying out a dam risk analysis, a K-value of 5.25 reduced the expected annual damage by 8.4% compared to the VEM, which represents a lowering of 17.3% of the maximum possible reduction, determined by the application of an optimizer based on mixed integer linear programming (MILP method).
PROCEEDINGS-ARTICLE 18 Reads 0 Citations Rule operation model for dams with gate-controlled spillways Alvaro Sordo-Ward, Iván Gabriel-Martin, Paola Bianucci, Andr... Published: 24 November 2016
Proceedings of The 1st International Electronic Conference on Water Sciences, doi: 10.3390/ecws-1-a010
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The study develops a rule operation model for gated spillways which improves the performance of the volumetric evaluation method (MEV). MEV was proposed by Giron (1988) and is largely used in common practice in Spain. The improvement was made by applying a corrective factor to the outflow discharge proposed by MEV method. The choice of the corrective factor was based on a multi-decision environment accounting for the number of improved cases and the amount of improvement. A Monte Carlo simulation environment was created to evaluate the method under a wide range of operating conditions. The environment includes the generation of storms and inflow hydrographs and their routing through the reservoir. The methodology was applied to the Talave basin, in the south-east of Spain. The improved method (called K method) was compared with other methods for the operation of gate-controlled spillways as the MEV and PLEM methods. The results showed that if the corrective factor K is higher than 1 the number of improved cases was significant, while if it is lower than 1 there was not improvement. The analysis of the relation between the return period and the devised method showed that by using the K method the percentage of improvement of both reducing maximum outflows and reducing maximum levels reached in the reservoir is greater for events with higher return periods than for the lower ones.
Article 2 Reads 3 Citations Impact of Hydrological Uncertainty on Water Management Decisions Álvaro Sordo-Ward, Isabel Granados, Francisco Martín-Carrasc... Published: 27 September 2016
Water Resources Management, doi: 10.1007/s11269-016-1505-5
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