Zabalza-Martínez J., Vicente-Serrano S.M., López-Moreno J.I., Calvo G.B., Savé R., Pascual D., Pla E., Morán-Tejeda E., Domínguez-Castro F., Tague C.L. (2018) The influence of climate and land-cover scenarios on dam management strategies in a highwater pressure catchment in Northeast Spain. Water (Switzerland). 10: 0-0.EnllaçDoi: 10.3390/w10111668
This paper evaluates the response of streamflow in a Mediterranean medium-scaled basin under land-use and climate change scenarios and its plausible implication on the management of Boadella-Darnius reservoir (NE Spain). Land cover and climate change scenarios supposed over the next several decades were used to simulate reservoir inflow using the Regional Hydro-Ecologic Simulation System (RHESsys) and to analyze the future impacts on water management (2021-2050). Results reveal a clear decrease in dam inflow (-34%) since the dam was operational from 1971 to 2013. The simulations obtained with RHESsys show a similar decrease (-31%) from 2021 to 2050. Considering the ecological minimum flow outlined by water authorities and the projected decrease in reservoir's inflows, different water management strategies are needed to mitigate the effects of the expected climate change. © 2018 by the authors.
Pascual D., Pla E., Fons-Esteve J., Abdul-Malak D. (2017) Climate change impacts on water availability and human security in the intercontinental biosphere reserve of the mediterranean (Morocco-Spain). Environmental Change and Human Security in Africa and the Middle East. : 75-93.EnllaçDoi: 10.1007/978-3-319-45648-5_4
The Mediterranean basin has been identified as one of the world most vulnerable regions to global change effects. Global and regional climate change scenarios foresee an increase in the average annual temperature over the planet’s mean. These scenarios project an increasing frequency of drought episodes adding to the complexity of water scarcity management and questioning the future sustainability of water resource uses. This study assesses the potential water vulnerability in the Intercontinental Biosphere Reserve of the Mediterranean (IBRM), located in the western side of the Mediterranean Basin between Spain (Europe) and Morocco (Africa). The vulnerability assessment proposes an innovative and multidisciplinary approach based on the use of climate change scenarios, a hydro-ecological model and the participation of stakeholders and local experts in expert meetings. Future scenarios draw a more arid climate for the IBRM, with more frequent water scarcity phenomena. A reduction of around 28.1-30.3 % is expected in stream flows by 2070. Agricultural water demands are expected to increase between 7.5 and 16 % in the Moroccan side in order to maintain the current production standards, whereas Spanish pastures are expected to maintain current productions with no need of supplementary water supply. Within forests, tree covered areas showed a higher potential vulnerability to future climate change than shrublands proving higher adaptation to arid conditions. Finally, the tourism will be impacted by the increase in summer temperature and in water supply shortages. Moreover, a significant spatial segregation of impacts is observed. Higher altitudes will be less affected by climate change and changes may be relevant to biodiversity but not to human activities. On the contrary, lower altitudes and coastal areas will experience an increasing water demand to sustain different uses by the end of the century in a higher water scarcity context. © Springer International Publishing Switzerland 2017.
Vicente-Serrano S.M., Zabalza-Martínez J., Borràs G., López-Moreno J.I., Pla E., Pascual D., Savé R., Biel C., Funes I., Azorin-Molina C., Sanchez-Lorenzo A., Martín-Hernández N., Peña-Gallardo M., Alonso-González E., Tomas-Burguera M., El Kenawy A. (2017) Extreme hydrological events and the influence of reservoirs in a highly regulated river basin of northeastern Spain. Journal of Hydrology: Regional Studies. 12: 13-32.EnllaçDoi: 10.1016/j.ejrh.2017.01.004
Study region The Segre basin (northeastern Spain). Study focus The Segre basin is extensively regulated, through a dense network of dams, during the second half of the 20th century. This study assessed the impact of river regulation on the evolution of hydroclimatological extreme events across the basin during the past six decades (1950–2013). We assessed whether the occurrence of floods and hydrological droughts has changed, and whether these changes have differed spatially between the headwaters and lower areas of the basin. For this purpose, we employed a set of hydroclimatological indices in order to quantify the evolution of the amount as well as the frequency of quantiles of high precipitation and flood events. Changes in these variables were assessed by means of the nonparametric Mann–Kendall Tau coefficient. New hydrological insights Results reveal a general reduction in the occurrence of extreme precipitation events in the Segre basin from 1950 to 2013, which corresponded to a general reduction in high flows measured at various gauged stations across the basin. While this study demonstrates spatial differences in the decrease of streamflow between the headwaters and the lower parts of the basin, mainly associated with changes in river regulation, there was no reduction in the frequency of the extraordinary floods. Changes in water management practices in the basin have significantly impacted the frequency, duration, and severity of hydrological droughts downstream of the main dams, as a consequence of the intense water regulation to meet water demands for irrigation and livestock farms. Nonetheless, the hydrological response of the headwaters to these droughts differed markedly from that of the lower areas of the basin. © 2017 The Author(s)
Vicente-Serrano S.M., Zabalza-Martínez J., Borràs G., López-Moreno J.I., Pla E., Pascual D., Savé R., Biel C., Funes I., Martín-Hernández N., Peña-Gallardo M., Beguería S., Tomas-Burguera M. (2016) Effect of reservoirs on streamflow and river regimes in a heavily regulated river basin of Northeast Spain. Catena. : 0-0.EnllaçDoi: 10.1016/j.catena.2016.03.042
Dams modify downstream hydrology because they alter natural river regimes and divert river flows. The Segre Basin is one of the main tributaries of the Ebro River in Northeastern Spain, and has a drainage area of 13,000km2. In this study, we used data on long-term (1951-2013) river flows and climatic series to analyze the downstream cumulative effect of dams on natural river regimes and the disassociation between changes in climate and runoff in the Segre Basin. The headwaters of this basin are in the Pyrenees Mountains, and water flow has been highly regulated since the second half of the twentieth century due to the construction of numerous dams. We compared long-term monthly averages of upstream and downstream sectors, and assessed the relationship between the climatic and hydrological time series. Our results show that the progressive increase of the impounded ratio index (reservoir capacity) increased the disassociation between climate and runoff. This markedly exacerbated the negative trend in downstream runoff, so this decline that cannot be solely explained by climatic changes. Our results provide evidence that reservoirs can cause a significant decline in downstream runoff and significant alterations of natural river regimes. © 2016 Elsevier B.V.
Pascual D., Pla E., Lopez-Bustins J.A., Retana J., Terradas J. (2015) Impacts of climate change on water resources in the Mediterranean Basin: a case study in Catalonia, Spain [Impacts du changement climatique sur les ressources en eau dans le bassin méditerranéen : une étude de cas en Catalogne, Espagne]. Hydrological Sciences Journal. : 0-0.EnllaçDoi: 10.1080/02626667.2014.947290
Most climate change projections show important decreases in water availability in the Mediterranean region by the end of this century. We assess those main climate change impacts on water resources in three medium-sized catchments with varying climatic conditions in northeastern Spain. A combination of hydrological modelling and climate projections with B1 and A2 IPCC emission scenarios is performed to infer future streamflows. The largest reduction (34%) in mean streamflows (for 2076–2100) is expected in the headwaters of the two wettest catchments, while lower decreases (25% of mean value for 2076–2100) are expected in the drier one. In all three catchments, autumn and summer are the seasons with the most notable projected decreases in streamflow, of 50% and 30%, respectively. Thus, ecological flows in the study area might be noticeably influenced by climate change, especially in the headwaters of the wet catchments.Editor Z.W. Kundzewicz © 2015 IAHS
Lopez-Bustins J.A., Pascual D., Pla E., Retana J. (2013) Future variability of droughts in three Mediterranean catchments. Natural Hazards. 69: 1405-1421.EnllaçDoi: 10.1007/s11069-013-0754-3
In the present study, we analyze the magnitude and frequency of long-term droughts throughout the present century in Catalonia in the north-eastern Iberian Peninsula (Spain). In fact, this western Mediterranean region has recently suffered one of the most extreme dry episodes (2006-2008) in the last decades. This calls for further study of future perspectives of drought variability at the local scale. We selected three medium-sized catchments on the Catalan littoral: Fluvià, Tordera and Siurana. We employed both instrumental and simulated temperature and rainfall data to calculate two multi-scalar drought indices: the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI). Instrumental data consisted of several weather stations for a recent period: 1984-2008. Future projections covering the 2001-2100 period were extracted from a dynamical downscaling procedure at a 15-km horizontal grid resolution, nesting the mesoscale model MM5 into the atmosphere-ocean coupled model ECHAM5/MPI-OM, performed by the Meteorological Service of Catalonia. We calculated 24-month SPI and SPEI values for the instrumental and simulated periods, and no changes were found in drought variability for the early twenty-first century. For the mid-century, high climatic variability was detected, as extremely dry and wet periods might alternate according to the SPI values. At the end of the present century, we generally detected, particularly in the dry catchment of southern Catalonia, Siurana, more severe and longer droughts than the last extreme drought (2006-2008). There is a need to implement appropriate and specific adaptation strategies for water management of each catchment over the next decades to reduce the risk of the forecasted drought conditions. © 2013 Springer Science+Business Media Dordrecht.
Savé R., de Herralde F., Aranda X., Pla E., Pascual D., Funes I., Biel C. (2012) Potential changes in irrigation requirements and phenology of maize, apple trees and alfalfa under global change conditions in Fluvià watershed during XXIst century: Results from a modeling approximation to watershed-level water balance. Agricultural Water Management. 114: 78-87.EnllaçDoi: 10.1016/j.agwat.2012.07.006
To evaluate the vulnerability of agriculture under Mediterranean conditions, the real water needs of agriculture in the Fluvià watershed (Catalonia, NE Spain) were estimated for the XXIst century using a combination of downscaled climate projections (ECHAM5 plus MM5) in two IPCC scenarios (B1 and A2), watershed hydrological model (SWAT) and FAO procedure to calculate crop potential evapotranspiration. In comparison with baseline conditions (1984-2008), climate projections predicted a 12% (B1) to 28% (A2) reduction in precipitation, and a 2.2°C (B1) to 3.6°C (A2) increment of mean annual temperature at the end of the XXI Century (2076-2100). The changes of the environmental conditions would affect the real water availability in different crops: water required for irrigation would increase significantly along the century, ranging from 40 to 250% depending on the crop, because of a direct decrease in the amount of water available along the growing season and because of the effects of the projected climatic conditions on potential evapotranspiration (ET 0) and on the phenology of these crops. Results are showing the high sensitivity of agriculture, despite its expanding technology, to changes in climate, and even more to site, plot, orchard or terroir conditions. © 2012 Elsevier B.V.
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