Moita-Montijo Bay saltmarsh and tidal flat change rates (1958-2018)

Saltmarsh and tidal flat change rates were determined for the period of 1958 to 2018, for the Moita-Montijo Bay (Tagus Estuary, Portugal). Rates were determined only for the exposed saltmarsh. No rates were calculated for sheltered saltmarsh (saltmarsh inside abandoned saltpans and similar structures). Saltmarsh margins were delineated in ArcMap, using, as the carthographic basis, orthorectified aerial photgraphs from 1958 and orthophotomaps from 1995 and 2018 (from Direção Geral do Território (DGT)).

Tidal flat change rates were determined for the period of 1977 to 2018, in the north and south banks of the Montijo Channel (Moita-Montijo Bay, Tagus Estuary, Portugal). Rates were determined only for the Montijo Channel margins. The tidal flat margins were delineated in ArcMap, using, as the carthographic basis, orthorectified aerial photgraphs from 1977 and orthophotomaps from 1995 and 2018 (from DGT).

The Digital Shoreline Analysis System (DSAS) in ArcMap was used to calculate the End Point Rates (EPR) between the margins (See Himmelstoss et al. (2018) for details on how to the EPR is calculated using DSAS).

This dataset was produced in the scope of the Project Planta II*. Further details can be consulted in Martins et al. (2023).

Dataset:

• Saltmarsh change rates in the Moita-Montijo Bay (1958 to 1995) (Tagus Estuary, Portugal) = rates_smarsh_moitamontijobay_1958_1995.shp
• Saltmarsh change rates in the Moita-Montijo Bay (1995 to 2018) (Tagus Estuary, Portugal) = rates_smarsh_moitamontijobay_1995_2018.shp
• Tidal flat change rates in the north bank of the Montijo Channel (1977 to 1995) (Moita-Montijo Bay, Tagus Estuary, Portugal) = rates_tf_nb_moitamontijobay_1977_1995.shp
• Tidal flat change rates in the north bank of the Montijo Channel (1995 to 2018) (Moita-Montijo Bay, Tagus Estuary, Portugal) = rates_tf_nb_moitamontijobay_1995_2018.shp
• Tidal flat change rates in the south bank of the Montijo Channel (1977 to 1995) (Moita-Montijo Bay, Tagus Estuary, Portugal) = rates_tf_sb_moitamontijobay_1977_1995.shp
• Tidal flat change rates in the south bank of the Montijo Channel (1995 to 2018) (Moita-Montijo Bay, Tagus Estuary, Portugal) = rates_tf_sb_moitamontijobay_1995_2018.shp

Please cite the paper where this dataset is discussed as Martins, D., Alves da Silva, A., Duarte, J., Canário, J., & Vieira, G. (2023). Changes in vessel traffic disrupt tidal flats and saltmarshes in the Tagus Estuary, Portugal. Estuaries and Coasts. DOI: https://doi.org/10.1007/s12237-023-01198-7

*Project Planta II - PTDC/CTA-GQU/31208/2017, co-funded by the European Regional Development Fund (ERDF), through the financing Regional Operational Program of Lisbon, and by the Portuguese Science and Technology Foundation (FCT), through the national funds (PIDDAC).