Search Results (26)

Detailed modelling of water dynamics at the catchment is of paramount importance for the optimal management and allocation of water resources. The main objective of this work is to present a set of QGIS-based routines for processing easily available geographical information to deliver inputs for integration into hydrological models developed in the Python environment. We present QGIS processes that deliver open format exchangeable files with physical information required for hydrological modelling, allowing a better tailoring of hydrological modelling tasks compared to other blinded existing models. We present the general framework by processing spatial information and running a set of hydrological models in different cases studies in the Spanish Ebro River basin, proving the utility of the proposed method for applying complex and tailored hydrological simulations. Full article

Understanding individual movement patterns in stream-resident salmonids is critical for conservation and river management, particularly in Mediterranean streams characterized by high environmental variability. We tagged 997 Mediterranean brown trout (Salmo trutta complex) and conducted an 11-month mark–recapture study using Passive Integrated Transponder (PIT) technology to assess movement behavior in the Flamisell River (Ebro Basin, northeastern Iberian Peninsula). Movements followed a leptokurtic distribution, with 81.8% of the individuals classified as sedentary (median movement = 24.9 m) and 18.2% as mobile (median movement = 376.2 m). Generalized linear models revealed distinct drivers of fish movement for each group. In sedentary trout, movement was mainly influenced by mesohabitat type, season, sex, and body size, with males and larger individuals moving farther. In mobile trout, mesohabitat type, density, and body size were key predictors. Movement patterns were repeatable over time, indicating consistent behavioral tendencies. These results support a bimodal movement strategy and highlight the importance of individual variation. Conservation planning should account for both sedentary and mobile groups to preserve functional and genetic connectivity and improve resilience of Mediterranean streams. Full article

Loess–palaeosol sequences (LPSs) are continuous records of palaeoenvironmental and palaeoclimatic conditions during the Quaternary. This study includes 17 LPS located in the NE of the Iberian Peninsula, irregularly distributed, associated with different river basins: the Ebro Basin, the Mora Basin, and the Ter sub-basin. The soils developed on these loess deposits present a loam–sandy texture, coarser than the typical loess, ochre in colour, with variable thickness (1–12 m), calcareous composition (20–45% CaCO₃ eq.), very low or null organic matter (OM), and basic pH. These deposits have been classified as desert LPS, whose pedogenesis is mainly associated with the redistribution of calcium carbonate and, in some cases, gypsum. Several methodologies have been applied to determine their mineralogical, physical, and chemical characteristics and date them by luminescence techniques. In addition, some relevant pedofeatures (porosity, CaCO₃, gypsum, etc.) have been characterised in detail. The aims of the present study have been to know the pedogenic development of the LPS by defining the main soil-forming factors that have affected them in order to associate these factors with the characteristic palaeoclimatic and palaeoenvironmental conditions reported in this area over time and to improve the understanding of soil evolution. Full article

The Iberian region relies heavily on groundwater and is highly vulnerable to climate variability, making it crucial to understand factors influencing water availability. The aim of this research was to assess how large-scale climate patterns affect total water storage anomalies (TWSAs) in Iberia, particularly in relation to persistent droughts and floods. To address this, I analyzed TWSAs derived from a reconstructed dataset (GRACE-REC) spanning from 1980 to 2019, first at the scale of the entire Iberian Peninsula and then across its main river basins. The links between the North Atlantic Oscillation (NAO), East Atlantic (EA) and Scandinavian (SCAND) patterns, TWSAs, and hydrological extremes were quantified using wavelet and principal component analysis. The results reveal that the NAO exerts the strongest multiyear influence on TWSAs, with periodicities of approximately 10 and 6.5 years, particularly in the southern river basins (Tagus, Guadiana, and Guadalquivir). EA and SCAND have stronger influences in the northern basins (Douro, Minho, and Ebro), driving 2- to 3.5-year cycles. Coupled phases of climate patterns, such as NAO+ and EA− (or SCAND−), correspond to extreme droughts, whereas NAO− and EA+ (or SCAND+) correspond to wet conditions. Full article

The European catfish (Silurus glanis Linnaeus, 1758) was introduced into the Ebro Basin in Spain in 1974 for recreational fishing. Since then, the species has spread throughout the country’s river basins, reaching the Iznájar Reservoir (Guadalquivir River Basin) in 2011. This area is of great ecological and economic relevance, especially as it includes the Doñana National Park, one of the most important nature reserves in Europe. Recently, the presence of catfish has been reported in the lower reaches of the river. In this work, we used non-invasive vertical and horizontal hydroacoustic surveys and environmental DNA river sampling to unravel the actual distribution and dispersal pattern of the species in the lower Guadalquivir River. The hydroacoustic profiles and the species-specific detections by real-time PCR (qPCR) and droplet digital PCR (ddPCR) showed that these non-invasive methods allow the detection and quantification of catfish and provide valuable information on the species’ presence. We have confirmed the presence of catfish in most of the study area, including downstream areas of the Guadalquivir Basin. The results suggest the possibility of other isolated introductions and/or human-mediated movements of specimens, and imply that a coordinated catfish prevention and mitigation strategy is therefore urgently needed. Full article

The Catalan chub, Squalius laietanus, was described in 2007 and has recently reached Vulnerable status on the IUCN Red List of Threatened Species. The assigned range for this species includes the lower course of the Ebro River in Spain and northwards to the Tech, Têt, Agly, and Massane Rivers in Southeastern France. In this study, 246 chub specimens caught at 15 sites in the nine main river basins of the Spanish range were barcoded by sequencing a 624 bp fragment of the mitochondrial COI gene. Squalius laietanus haplotypes were found in 68% of the fish caught. In a tributary of the Ebro River, all specimens (6%) were identified as the Tagus chub, S. pyrenaicus, another endemic Iberian chub species. The remaining fish (26%) had a haplotype typical of the European chub, S. cephalus, populations outside Spain. This haplotype was present in six sites in four basins, being particularly abundant in the Ebro River. Considering that Squalius species can hybridize with other native and non-native cyprinid species, the potential co-occurrence of several species in the same site or basin raises concerns about the real extent of an exclusive range for the Catalan chub and the integrity of its native gene pools throughout its range. Full article

The tension between rivers and cities reaches its highest expression in urban river basins. Given the high level of interaction between natural and cultural factors in many riverfronts, an integral project design is essential. The large number of urban river basin enhancement cases that have been conducted has resulted in a large amount of urban scientific literature. The multifaceted nature of these systems renders their analysis and contextualization a challenging endeavor. The objective of this research is to propose a novel evaluation tool based on a reformulation of Lynch’s theory of urban form performance, which has been updated from a landscape urbanism perspective. The conceptual framework provides a comprehensive method for translating diverse design strategies into comparable and meaningful categories. The results illustrate the impact of urban riverbank requalification initiatives on the formal quality dimensions of the city–river socio-ecological system. The assessment tool was applied to two cases: the Ebro River in Zaragoza (Spain) and the Isar River in Munich (Germany). Despite differences between the cases, comparative analysis revealed similar levels of urban landscape quality parameters and common elements that can provide new insights when considering the solutions applied and the degree of improvement in quality and river–city cohesion achieved with these projects. Full article

One of the main problems arising in inland waterbodies is nutrient enrichment that accelerates eutrophication, causing massive cyanobacteria blooms and degrading aquatic ecosystems. This study focused on physical/chemical factors that affect cyanobacteria of 30 reservoirs in the Ebro River basin within the Iberian Peninsula of northeastern Spain. The abundance of cyanobacteria was assessed as total cell number, total biovolume, and the indicator pigment, total phycocyanin (PC). In addition, empirical measurements for PC were compared to PC estimated from remote sensing. Variables assessed for correlation with cyanobacteria abundance included temperature, pH, light availability inferred from Secchi depth, water residence time, total nitrogen, dissolved inorganic nitrogen, total phosphorus, soluble reactive phosphorus, silica, and total phytoplankton biomass as chlorophyll a. These variables were also assessed with a multi-statistical principal component analysis for relationships with cyanobacteria abundance. Cyanobacteria cell number and biovolume were positively correlated with temperature, total nitrogen, total phosphorus, and water residence time, and negatively correlated with silica. High PC concentrations were documented in the reservoirs, and satellite images from remote sensing showed the PC spatial distribution and heterogeneity in the reservoirs. The PCA results show that some variables, such as nitrogen and phosphorus, are closely related to the abundance of cyanobacteria, while other variables such as silica do not show a clear relationship. This study contributes to the knowledge base about inland waterbodies from a physical/chemical perspective, which had not been done before in the Ebro Basin, including the application of analytic tools such as remote sensing. Full article

Climate–atmospheric patterns affect ecological processes. The El Niño Southern Oscillation (ENSO) represents the strongest global source of climate variability at annual scales, but its impacts on Mediterranean forests are still understudied. Here, ENSO signals recorded by river flow and radial growth series of Mediterranean riparian forests are uncovered in the middle Ebro basin, northeastern Spain. A chronology or mean series of tree ring widths (period 1970–2018, 27 trees) was built for narrow-leaved ash (Fraxinus angustifolia). Growth indices increased as the river flow did during the prior winter and from May to September. Ash growth indices and river flow of the hydrological year were positively related (r = 0.54, p < 0.001), suggesting that a higher soil moisture enhances growth. This correlation remained significant after taking out the influence of precipitation. Ash growth indices (r = −0.46, p = 0.001) and river flow during the hydrological year (r = −0.30, p = 0.03) were negatively associated with the January Southern Oscillation Index (SOI). These relationships suggest that high SOI values corresponding to La Niña events lead to reduced river flow, thus decreasing ash radial growth. Further approaches could be used to better understand how the ENSO impacts drought-prone riparian forests subjected to increasing aridity. Full article

The growing need for water supply, because of the massive population growth, causes continuous problems. Water is subjected to great pressures, diminishing its quality and affecting the flora and fauna that depend directly or indirectly on it, as well as humans. These aspects increase the cost of its treatment or the loss of water bodies for human consumption. One of the main problems that appear in inland water bodies is nutrient enrichment, which is associated with problems of eutrophication or even hypertrophy, which can cause massive blooms of cyanobacteria, altering or destroying aquatic ecosystems. This work focuses on the study of different physicochemical variables of inland water bodies in the NE of the Iberian Peninsula in the Ebro river basin, such as temperature, residence time, pH, total nitrogen, inorganic nitrogen, total phosphorus, orthophosphates, silicates and phycocyanin, in order to establish a relationship with cyanobacterial biovolumes and how they affect their proliferation. These variables were analyzed in the laboratory in order to, subsequently, carry out a correlation between variables and a multistatistical analysis of components. On the other hand, remote sensing was used by applying a previously developed algorithm to evaluate phycocyanin concentrations and compare them with in situ measurements. This provided significant correlations between the temperature, total nitrogen, total phosphorus and residence time according to the biovolume of cyanobacteria; we also obtained a negative correlation, for example, in the case of silicates. The results showed alarming levels of cyanobacteria in a large part of the reservoirs, which should be studied due to the danger associated with the possible appearance of cyanotoxins. Full article

The introduction of invasive alien species (IAS) is a severe problem in ecosystems worldwide, heavily impacting biodiversity and especially endemic species. This situation is especially worrying in the Iberian Peninsula, since Spain and Portugal’s rivers and lakes host an outstanding richness of endemic freshwater species. Ignorance about IAS presence and distribution is a serious problem that hampers its management. Regarding invasive fish species, difficulties in sampling and studying the ichthyofauna of lentic and deep waters, where many IAS inhabit, comprise some of the reasons for this lack of knowledge. In this study, we sampled the fish community of ten impounded waters in Navarre (Ebro River Basin, Spain) using multi-mesh gillnets. Four sampling points were dams located in rivers, and the remaining points were ponds. One of these ponds had a direct connection with a water channel, and another was found in a flood plain, so it connects with a nearby river in floods. The remaining ponds did not have a direct connection to any major river. A total of 14 fish species were detected (9 of which were IAS (64.3%)), with 3383 specimens collected (56% IAS). Only one of the analyzed dams did not contain IAS. Numerically, the most abundant fish was the exotic bleak (Alburnus alburnus) (almost 44% of the captures), followed by the native Ebro nase (Parachondrostoma miegii) (23.4%). The most widely distributed IAS were the common carp (Cyprinus carpio) and the bleak, which appeared in 70% and 60% of the sampling stations, respectively. IAS in dams accounted for 50% of the total species found and represented 21.3% of fish abundance. On the other hand, 64.3% of species in ponds were IAS, reaching 68.3% of fish abundance. This percentage increased when analyzing only the ponds without a natural connection with rivers or canals, where IAS introduction would be anthropic. IAS species in these points represented 71.4% of total fish species and 92.5% of the abundance of fish. Full article

Water monitoring is key to determining the presence of potentially hazardous substances related to urban activities and intensive farming. This research aimed to perform a long-term (four years) quantitative monitoring of selected antibiotics (azithromycin, enrofloxacin, trimethoprim and sulfadiazine) both in rivers and wastewaters belonging to the Ebro River basin (North of Spain). The target antibiotics were chosen on the basis of a preliminary multispecies screening. The analysis of the antibiotics was carried out by LC-MS/MS on wastewater-treatment plant (WWTP) effluent, effluents of a slaughterhouse and hospital, rivers downstream and upstream of these WWTPs, and rivers close to extensive farming areas. The ANOVA test was performed to study the significant differences between the points exposed to concrete emission sources and antibiotic concentration. The monitoring, carried out from 2018 to 2020, has been essential to illustrating the presence of the most abundant antibiotics that were detected in the Ebro River basin. Enrofloxacin has appeared in river waters in significant concentrations, especially near intensive farming, meanwhile azithromycin has been frequently detected in wastewaters. Full article

This article presents and reviews the soil salinity data provided by a rescued vintage agronomic report on an irrigated area of 35,875 ha located in the center of the Ebro River basin, in the NE of mainland Spain. These data come from a soil sampling campaign conducted from May to the first half of July 1975 for the purpose of delineating saline and non-saline soils. The agronomic report was produced in response to demands from farmers to combat soil salinity, and represents the state of the art in those years for salinity studies. Our paper presents the scrubbed soil salinity data for this year, checking their consistency and locating the study sites. The main finding is the unearthing of this heritage report and the discussion of its soil salinity data. We show that the report supplies an assessment and a baseline for further soil salinity tracking by conducting new measurements either by direct soil sampling or by nondestructive techniques, providing an estimate of soil salinity at different locations. This task is feasible, as shown in our previously published articles involving nearby areas. A comparison of the salt amount in the soil over the years would provide a means to evaluate irrigation methods for sustainable land management. This comparison can be conducted simultaneously with analysis of other agricultural features described in the report for the irrigation district in 1975. Full article

The vast majority of reservoirs, although built for irrigation and water supply purposes, are also used as regulation tools during floods in river basins. Thus, the selection of the most suitable model when facing the simulation of a flood wave in a combination of river reach and reservoir is not direct and frequently some analysis of the proper system of equations and the number of solved flow velocity components is needed. In this work, a stretch of the Ebro River (Spain), which is the biggest river in Spain, is simulated solving the Shallow Water Equations (SWE). The simulation model covers the area of river between the city of Zaragoza and the Mequinenza dam. The domain encompasses 721.92 km${}^2$ with 221 km of river bed, of which the last 75 km belong to the Mequinenza reservoir. The results obtained from a one-dimensional (1D) model are validated comparing with those provided by a two-dimensional (2D) model based on the same numerical scheme and with measurements. The 1D modelling loses the detail of the floodplain, but nevertheless the computational consumption is much lower compared to the 2D model with a permissible loss of accuracy. Additionally, the particular nature of this reservoir might turn the 1D model into a more suitable option. An alternative technique is applied in order to model the reservoir globally by means of a volume balance (0D) model, coupled to the 1D model of the river (1D-0D model). The results obtained are similar to those provided by the full 1D model with an improvement on computational time. Finally, an automatic regulation is implemented by means of a Proportional-Integral-Derivative (PID) algorithm and tested in both the full 1D model and the 1D-0D model. The results show that the coupled model behaves correctly even when controlled by the automatic algorithm. Full article

The Cenozoic sedimentary basins in the Iberian Peninsula show a change from long-term basin infill to incision, a transition that indicates a period of major drainage reorganization that culminated in the throughflow of the networks to the Atlantic and Mediterranean oceans. Both the cause of the transition from aggradation to degradation and the linkages to tectonic, climatic, and geomorphic events hinge on the chronology of the fluvial network incision and excavation of the basin’s sedimentary fills. In this paper, we describe the first chronologic data on the highest fluvial terraces of the upper area of the Ebro River, one of the largest fluvial systems in the Iberian Peninsula, to determine the onset of incision and excavation in the basin. For this purpose, we combine electron spin resonance (ESR) and paleomagnetism methods to date strath terraces found at 140, 90, and 85 m above the current river level. Our results show ages of ca. 1.2 and 1.5 Ma for the uppermost river terraces in the upper Ebro catchment, constraining the minimum age of the entrenchment of the upper Ebro River. Full article