{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T06:45:32Z","timestamp":1777531532635,"version":"3.51.4"},"reference-count":45,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2019,9,14]],"date-time":"2019-09-14T00:00:00Z","timestamp":1568419200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/AAG-MAA\/6899\/2014"],"award-info":[{"award-number":["PTDC\/AAG-MAA\/6899\/2014"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100010661","name":"Horizon 2020","doi-asserted-by":"publisher","award":["Grant Agreement Number 641739"],"award-info":[{"award-number":["Grant Agreement Number 641739"]}],"id":[{"id":"10.13039\/100010661","id-type":"DOI","asserted-by":"publisher"}]},{"name":"POR Lisboa 2020","award":["LISBOA-01-0145-FEDER-022153"],"award-info":[{"award-number":["LISBOA-01-0145-FEDER-022153"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Geosciences"],"abstract":"<jats:p>Droughts reduce freshwater availability and have negative environmental, economic, and social impacts. In estuaries, the dynamics between the saltwater and the freshwater can be affected during droughts, which can impact several natural resources and economic sectors negatively. The Tagus estuary is one of the largest estuaries in Europe and supports diverse uses and activities that can be affected by the saltwater intrusion (e.g., agriculture). This study assesses the saltwater intrusion in the upper reaches of the Tagus estuary using a process-based model to explore different scenarios of freshwater discharge and sea level rise. For the river discharge and mean sea level rise scenarios analyzed, salinity can reach concentrations that are inadequate for irrigation when the mean Tagus river discharge is similar or lower than the ones observed during recent droughts (22\u201344 m3\/s). Lower river discharges aggravate the consequences. Results also show that the salinity increases with the duration of the droughts. In contrast, the impact of a moderate sea level rise on salinity intrusion is modest when compared with the impact of low river discharges. These findings contribute to support the management of the agricultural activities in the upper Tagus estuary and the water resources in the Tagus river basin.<\/jats:p>","DOI":"10.3390\/geosciences9090400","type":"journal-article","created":{"date-parts":[[2019,9,16]],"date-time":"2019-09-16T03:17:57Z","timestamp":1568603877000},"page":"400","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":35,"title":["Saltwater Intrusion in the Upper Tagus Estuary during Droughts"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9926-1918","authenticated-orcid":false,"given":"Marta","family":"Rodrigues","sequence":"first","affiliation":[{"name":"Laborat\u00f3rio Nacional de Engenharia Civil, Avenida do Brasil, 101, 1700-066 Lisbon, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4667-1945","authenticated-orcid":false,"given":"Andr\u00e9 B.","family":"Fortunato","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio Nacional de Engenharia Civil, Avenida do Brasil, 101, 1700-066 Lisbon, Portugal"}]},{"given":"Paula","family":"Freire","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio Nacional de Engenharia Civil, Avenida do Brasil, 101, 1700-066 Lisbon, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,9,14]]},"reference":[{"key":"ref_1","first-page":"3","article-title":"Drought as a natural hazard: Concepts and definitions","volume":"Volume 1","author":"Wilhite","year":"2000","journal-title":"Drought: A Global Assessment"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"801","DOI":"10.5194\/nhess-16-801-2016","article-title":"Impacts of European drought events: Insights from an international database of text-based reports","volume":"16","author":"Stahl","year":"2016","journal-title":"Nat. Hazards Earth Syst. Sci."},{"key":"ref_3","unstructured":"Poljan\u0161ek, K., Ferrer, M.M., De Grove, T., and Clark, I. (2017). Science for Disaster Risk Management 2017: Knowing Better and Losing Less, Office of the European Union."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"94","DOI":"10.1016\/j.hal.2017.01.011","article-title":"Impacts of the 2014 severe drought on the Microcystis bloom in San Francisco Estuary","volume":"63","author":"Lehman","year":"2017","journal-title":"Harmful Algae"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"627","DOI":"10.4319\/lo.2011.56.2.0627","article-title":"Severe droughts reduce estuarine primary productivity with cascading effects on higher trophic levels","volume":"56","author":"Wetz","year":"2011","journal-title":"Limnol. Oceanog."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.ecss.2015.08.023","article-title":"Drought and flood effects on macrobenthic communities in the estuary of Australia\u2019s largest river system","volume":"165","author":"Dittmann","year":"2015","journal-title":"Est. Coast. Shelf Sci."},{"key":"ref_7","unstructured":"Stocker, T.F., Qin, D., Plattner, G.K., Tignor, M., Allen, S.K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P.M. (2013). Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press."},{"key":"ref_8","unstructured":"Masson-Delmotte, V., Zhai, P., P\u00f6rtner, H.O., Roberts, D., Skea, J., Shukla, P.R., Pirani, A., Moufouma-Okia, W., P\u00e9an, C., and Pidcock, R. (2018). Impacts of 1.5 \u00b0C Global Warming on Natural and Human Systems. Global Warming of 1.5 \u00b0C. An IPCC Special Report on the Impacts of Global Warming of 1.5 \u00b0C above Pre-Industrial Levels and Related Global Greenhouse Gas Emission Pathways, in the Context of Strengthening the Global Response to the Threat of Climate Change, Sustainable Development, and Efforts to Eradicate Poverty, Intergovernmental Panel on Climate Change."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1007\/s10750-015-2200-x","article-title":"Impacts of droughts and low flows on estuarine water quality and benthic fauna","volume":"753","author":"Palmer","year":"2015","journal-title":"Hydrobiologia"},{"key":"ref_10","unstructured":"Gilbert, S., Lackstrom, K., and Tufford, D. (2012). The Impact of Drought on Coastal Ecosystems in the Carolinas, Carolinas Integrated Sciences and Assessments. Research Report: CISA-2012-01."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"753","DOI":"10.1175\/BAMS-D-15-00171.1","article-title":"Development of a coastal drought index using salinity data","volume":"98","author":"Conrads","year":"2017","journal-title":"Am. Meteorol. Soc."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1007\/s12237-011-9423-5","article-title":"Climate Forcing and Salinity Variability in Chesapeake Bay, USA","volume":"35","author":"Xu","year":"2012","journal-title":"Estuaries Coasts"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.ocemod.2015.12.007","article-title":"Evaluation of a long-term hindcast simulation for the Columbia River estuary","volume":"99","author":"Baptista","year":"2016","journal-title":"Ocean Model."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Liu, W.C., and Chan, W.T. (2016). Assessment of climate change impacts on water quality in a tidal estuarine system using a three-dimensional model. Water, 8.","DOI":"10.3390\/w8020060"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.oceaneng.2019.05.029","article-title":"Numerical modelling study of seawater intrusion in Indus River Estuary, Pakistan","volume":"184","author":"Wang","year":"2019","journal-title":"Ocean Eng."},{"key":"ref_16","unstructured":"Rodrigues, R. (2007, January 17\u201318). Coping with Hydrological Risk in Shared Rivers\u2014The Iberian Peninsula Case. Proceedings of the 1st Thematic Workshop of the EU Coordination Action RISKBASE, Monitoring and Assessment of River Pollutants, Lisbon, Portugal."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"238","DOI":"10.1016\/j.envsci.2015.04.010","article-title":"Flooding hazard in the Tagus estuarine area: The challenge of scale in vulnerability assessments","volume":"51","author":"Tavares","year":"2015","journal-title":"Environ. Sci. Policy"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"763","DOI":"10.3934\/environsci.2017.6.763","article-title":"Assessment of a three-dimensional baroclinic circulation model of the Tagus estuary","volume":"4","author":"Rodrigues","year":"2017","journal-title":"AIMS Environ. Sci."},{"key":"ref_19","unstructured":"Freitas, A., Luis, A., Fortunato, A., Villanueva, A., Martins, B., Russo, B., Strehl, C., Martinez, E., Alves, E., and Bergsma, E. (2017). Risk Identification: Relevant Hazards, Risk Sources and Factors, Deliverable 4.2, BINGO."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"324","DOI":"10.3390\/w6020324","article-title":"Assessing the Impacts of Sea Level Rise on Salinity Intrusion and Transport Time Scales in a Tidal Estuary, Taiwan","volume":"6","author":"Liu","year":"2014","journal-title":"Water"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1016\/j.ocemod.2016.05.002","article-title":"Seamless cross-scale modeling with SCHISM","volume":"102","author":"Zhang","year":"2016","journal-title":"Ocean Model."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.jmarsys.2014.05.022","article-title":"Modeling SST and chlorophyll patterns in a coupled estuary-coastal system of Portugal: The Tagus case study","volume":"147","author":"Vaz","year":"2015","journal-title":"J. Mar. Syst."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Pablo, H., Sobrinho, J., Garcia, M., Campuzano, F., Juliano, M., and Neves, R. (2019). Validation of the 3D-MOHID Hydrodynamic Model for the Tagus Coastal Area. Water, 11.","DOI":"10.3390\/w11081713"},{"key":"ref_24","unstructured":"Rodrigues, A.C., Diogo, P.A., and Cola\u00e7o, P.D. (2012). Intrus\u00e3o Salina no Tro\u00e7o Final do Rio Tejo Face a Cen\u00e1rios de Altera\u00e7\u00f5es Clim\u00e1ticas, Departamento de Ci\u00eancias e Engenharia do Ambiente, Faculdade de Ci\u00eancias da Universidade de Lisboa. Relat\u00f3rio Final."},{"key":"ref_25","unstructured":"Castanheiro, J.M. (1986). Distribution, transport and sedimentation of suspended matter in the Tejo Estuary, Estuarine processes: An application to the Tagus Estuary."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"65","DOI":"10.5894\/rgci515","article-title":"Evolution of the hydrodynamics of the Tagus estuary (Portugal) in the 21st century","volume":"15","author":"Guerreiro","year":"2015","journal-title":"Rev. Gest\u00e3o Costeira Integr."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1689","DOI":"10.1016\/S0278-4343(97)00047-2","article-title":"A three-dimensional model of tidal currents in the mouth of the Tagus Estuary","volume":"17","author":"Fortunato","year":"1997","journal-title":"Cont. Shelf Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/S0399-1784(99)80030-9","article-title":"On the effect of tidal flats on the hydrodynamics of the Tagus estuary","volume":"22","author":"Fortunato","year":"1999","journal-title":"Oceanol. Acta"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1016\/j.csr.2017.06.023","article-title":"A numerical study of the February 15, 1941 storm in the Tagus estuary","volume":"144","author":"Fortunato","year":"2017","journal-title":"Cont. Shelf Res."},{"key":"ref_30","unstructured":"APA\u2014Ag\u00eancia Portuguesa do Ambiente (2012). Plano de Gest\u00e3o da Regi\u00e3o Hidrogr\u00e1fica do Tejo, Relat\u00f3rio T\u00e9cnico\u2014S\u00edntese."},{"key":"ref_31","unstructured":"Rodrigues, R., Cunha, R., and Rocha, F. (2009). Evaluation of river inflows to the Portuguese estuaries based on their duration curves (in Portuguese). EMMA Proj. Rep., 1\u201340."},{"key":"ref_32","unstructured":"Neves, F.S. (2010). Dynamics and Hydrology of the Tagus Estuary: Results from In Situ Observations. [Ph.D. Thesis, Universidade de Lisboa]."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.ocemod.2007.11.005","article-title":"SELFE: A semi-implicit Eulerian-Lagrangian finite-element model for cross-scale ocean circulation","volume":"21","author":"Zhang","year":"2008","journal-title":"Ocean Model."},{"key":"ref_34","unstructured":"Ye, F., Zhang, Y.J., Yu, H.C., Sun, W., Moghimi, S., Myers, E., Nunez, K., Zhang, R., Wang, H.V., and Roland, A. Simulating storm surge and compound flooding events with a creek-to-ocean model: Importance of baroclinic effects. Ocean Model., in review."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.ocemod.2014.10.003","article-title":"A new vertical coordinate system for a 3D unstructured-grid model","volume":"85","author":"Zhang","year":"2015","journal-title":"Ocean Model."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1274","DOI":"10.1016\/j.ecolmodel.2009.02.002","article-title":"Three-dimensional modeling of the lower trophic levels in the Ria de Aveiro (Portugal)","volume":"220","author":"Rodrigues","year":"2009","journal-title":"Ecol. Model."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.ocemod.2016.10.004","article-title":"A 3D, cross-scale, baroclinic model with implicit vertical transport for the Upper Chesapeake Bay and its tributaries","volume":"107","author":"Ye","year":"2016","journal-title":"Ocean Model."},{"key":"ref_38","unstructured":"Macedo, M.E.Z. (2006). Caracteriza\u00e7\u00e3o de Caudais, Rio Tejo, CCDR de Lisboa e Vale do Tejo."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1016\/j.envsoft.2014.07.016","article-title":"Reconstruction of 2D river beds by appropriate interpolation of 1D cross-sectional information for flood simulation","volume":"61","year":"2014","journal-title":"Environ. Model. Softw."},{"key":"ref_40","unstructured":"Kristvik, E., Mouskoundis, M., Iacovides, I., Iacovides, A., Martinez, M., Sanchez, P., Russo, B., Malgrat, P., Zoumides, C., and Giannakis, E. (2017). Compilation Report on Initial Workshops at the Six Research Sites, Deliverable 5.2, BINGO."},{"key":"ref_41","first-page":"9","article-title":"Reflex\u00f5es sobre a monitoriza\u00e7\u00e3o dos recursos h\u00eddricos, a Conven\u00e7\u00e3o de Albufeira e o licenciamento de descargas nas massas de \u00e1gua, a prop\u00f3sito do incidente de polui\u00e7\u00e3o do rio Tejo de janeiro de 2018","volume":"39","author":"Henriques","year":"2018","journal-title":"Rev. Recur. H\u00eddricos"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2495","DOI":"10.5194\/gmd-10-2495-2017","article-title":"Synthesizing long-term sea level rise projections\u2014The MAGICC sea level model v2.0","volume":"10","author":"Nauels","year":"2017","journal-title":"Geosci. Model. Dev."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1016\/j.oceaneng.2015.11.031","article-title":"Determination of extreme sea levels along the Iberian Atlantic coast","volume":"111","author":"Fortunato","year":"2016","journal-title":"Ocean Eng."},{"key":"ref_44","unstructured":"Kpogo-Nuwoklo, K., Meredith, E., and Vagenas, C. (2017). Ensembles for Decadal Prediction Extremal Episodes Downscaled to 3-1km\/ 1h); Spatial Stochastic Precipitation Generator for Catchments, Deliverable 2.6, BINGO."},{"key":"ref_45","unstructured":"Alphen, H.J., Alves, E., Beek, T., Bruggeman, A., Camera, C., Fohrmann, R., Fortunato, A., Freire, F., Iacovides, A., and Iacovides, I. (2016). Characterization of the Catchments and the Water Systems, Deliverable 3.1, BINGO."}],"container-title":["Geosciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3263\/9\/9\/400\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:20:13Z","timestamp":1760188813000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3263\/9\/9\/400"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,9,14]]},"references-count":45,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2019,9]]}},"alternative-id":["geosciences9090400"],"URL":"https:\/\/doi.org\/10.3390\/geosciences9090400","relation":{},"ISSN":["2076-3263"],"issn-type":[{"value":"2076-3263","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,9,14]]}}}