Suchergebnisse

This research is funded by Spanish Ministry of Science, Innovation and Universities (AEI/FEDER/UE) through the projects CTM201677106-R and CTM2017-89531-R. Guadalquivir-LTER project was supported by IFAPA Research Projects PP.FEM.PPA201700.5 and PP.FEM. PP201900.5, 75% cofounded by European Maritime and Fisheries Fund (2014-2022), within the Spanish Operational Program "Fisheries and Maritime 2014-2020". MB and DGF acknowledge funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie, grant agreements 754446 (UGR Research and Knowledge Transfer Fund -Athenea3i) and 846843 (LitRivus), respectively. University of Granada/CBUA provided the funding for open access charges. Finally, the authors would like to thank the two anonymous reviewers and Editor for their valuable comments and suggestions. ; Microplastics (MPs) patterns in a weakly-stratified estuary were investigated using a combined approach of observations and modeling. The study was conducted in the Guadalquivir River Estuary, which is of high environmental value, yet significantly altered by human activities. The study aims to contribute to understanding and quantifying the land-ocean transport of MPs. Mean concentrations of MPs in the estuary were 0.041 items m(-3), with maximum values up to 0.20 items m(- 3), in agreement with the range reported in other estuaries. Polyethylene floating MPs were predominant. Relationships between increases in MP concentration and local rainfall events were identified in the middle estuary when there were no significant discharges from the head dam. Modeling results mimicked observations and revealed the effects of tidal straining, density-driven, and river flow-induced circulation on the net transport. Convergence of transports favors the MPs trapping in the vicinity of Don tilde ana National Park, overlapping the location of the Estuarine Turbidity Maximum. ; Spanish Ministry of Science, Innovation and Universities (AEI/FEDER/UE) CTM201677106-R CTM2017-89531-R ; IFAPA Research Projects PP.FEM.PPA201700.5 PP.FEM. PP201900.5 ; European Union's Horizon 2020 research and innovation programme 754446 846843 ; University of Granada/CBUA

An edited version of this paper was published by AGU. Copyright (2012) American Geophysical Union. ; This study analyzes tide transformation in the Guadalquivir estuary (SW Spain). When fresh water discharges are less than 40 m3/s, the estuary is tidally-dominated (flood-dominated) and well mixed. Under such conditions, the estuary can be divided into three stretches, each characterized by a different tide propagation process. In the first stretch of 25 km, the dominant process is diffusion. In the next stretch, approximately over 35 km length, convergence and friction processes are in balance. At the head of the estuary, in the last stretch, the tidal motion is partially standing because of tidal reflection on the Alcalá del Río dam, located 110 km upstream from the estuary mouth. The reflection coefficient R varies with the frequency; for diurnal constituents its magnitude ∣RD∣ is 0.25; this value increases in the case of semi-diurnal (∣RS∣ ≈ 0.40), and quarter-diurnal constituents (∣RQ∣ ≈ 0.65), and reaches its minimum at the sixth-diurnal components (∣RX∣ ≈ 0.10). The tidal reflection can generate residual currents that have consequences in the bed morphology. Furthermore, when the fresh water discharges are greater than 400 m3/s, the estuary is fluvially-dominated and the water level can be calculated as the linear superposition of tide and river contributions. However, superposition arguments do not hold for currents at any point in the estuary. ; This research was funded by the Spanish Ministry of Science and Innovation (project CTM2009-10520/MAR) and by the Department of Innovation, Science and Business of the Andalusian Regional Government through the project P09-TEP-4630 and a research contract between the University of Granada and the CSIC (under the direction of the Port Authority of Seville). ; Peer reviewed

Microplastics (MPs) patterns in a weakly-stratified estuary were investigated using a combined approach of observations and modeling. The study was conducted in the Guadalquivir River Estuary, which is of high environmental value, yet significantly altered by human activities. The study aims to contribute to understanding and quantifying the land-ocean transport of MPs. Mean concentrations of MPs in the estuary were 0.041 items m(-3), with maximum values up to 0.20 items m(- 3), in agreement with the range reported in other estuaries. Polyethylene floating MPs were predominant. Relationships between increases in MP concentration and local rainfall events were identified in the middle estuary when there were no significant discharges from the head dam. Modeling results mimicked observations and revealed the effects of tidal straining, density-driven, and river flow-induced circulation on the net transport. Convergence of transports favors the MPs trapping in the vicinity of Don tilde ana National Park, overlapping the location of the Estuarine Turbidity Maximum. ; This research is funded by Spanish Ministry of Science, Innovation and Universities (AEI/FEDER/UE) through the projects CTM201677106-R and CTM2017-89531-R. Guadalquivir-LTER project was supported by IFAPA Research Projects PP.FEM.PPA201700.5 and PP.FEM. PP201900.5, 75% cofounded by European Maritime and Fisheries Fund (2014-2022), within the Spanish Operational Program "Fisheries and Maritime 2014-2020". MB and DGF acknowledge funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie, grant agreements 754446 (UGR Research and Knowledge Transfer Fund -Athenea3i) and 846843 (LitRivus), respectively. University of Granada/CBUA provided the funding for open access charges. Finally, the authors would like to thank the two anonymous reviewers and Editor for their valuable comments and suggestions.

The authors would thank to the staff of the Environmental Fluid Dynamics research group (GDFA, University of Granada) for their support during the field campaign. ; Improving current understanding of hydrodynamics and sediment dynamics in complex tidal embayments is of major importance to face future challenges derived from climate change and increasing human pressure. This work deepens the knowledge of the hydro-morphodynamics of complex creek networks that connect basins with different characteristics, identifying their morphodynamic trends and the potential impacts of channel deepening. We selected two tidal creeks which flow through salt marshes and tidal flats of the Cádiz Bay (SW Spain) in a singular network due to their double connection to the Atlantic Ocean and the inner bay. We study the interactions between tidal waves that penetrate into the creeks from these two different bodies of water, analyzing the tidal asymmetry and the morphodynamic tendencies of the system. For the analysis, we set up a hydro-morphodynamic model specifically developed for areas with very shallow and complex channels. Results show that the tidal wave penetrates within the tidal network both from the inner Bay and the open ocean with different amplitudes, phases and flow velocities. There is also an asymmetric pattern for the tidal flows caused by the deformation of the dominant astronomical tidal constituents, M2 and M4, due to the non-linear interaction of tidal currents with the irregular creek geometry and bottom topography. Tidal asymmetry promotes the progressive infilling of the area where the tidal waves meet closing the connection between the open ocean and the inner bay, such an infilling trend being accelerated by human interventions. ; This work was funded by the Cádiz Bay Port Authority, the Department of Innovation, Science and Business of the Andalusian Regional Government (Project P09-TEP-4630), the Spanish Ministry of Economy and Competitiveness through the Projects CTM2009-10520-MAR, CTM2017-89531-R (PIRATES), BIA2015-65598-P (VIVALDI) and PCIN-2017-108, and by the "Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo", CYTED (project PROTOCOL 917PTE0538). The work of the first author was partially funded by the Andalusian Regional Government, Research Grant RNM-6352.