Spatio-Temporal Water Hyacinth Monitoring in the Lower Mondego (Portugal) Using Remote Sensing Data
Monitoring invasive plant species is a crucial task to assess their presence in affected ecosystems. However, it is a laborious and complex task as it requires vast surface areas, with difficult access, to be surveyed. Remotely sensed data can be a great contribution to such operations, especially f...
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MDPI AG
2022-12-01
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Series: | Plants |
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Online Access: | https://www.mdpi.com/2223-7747/11/24/3465 |
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author | Luís Pádua Lia Duarte Ana M. Antão-Geraldes Joaquim J. Sousa João Paulo Castro |
author_facet | Luís Pádua Lia Duarte Ana M. Antão-Geraldes Joaquim J. Sousa João Paulo Castro |
author_sort | Luís Pádua |
collection | DOAJ |
description | Monitoring invasive plant species is a crucial task to assess their presence in affected ecosystems. However, it is a laborious and complex task as it requires vast surface areas, with difficult access, to be surveyed. Remotely sensed data can be a great contribution to such operations, especially for clearly visible and predominant species. In the scope of this study, water hyacinth (<i>Eichhornia crassipes</i>) was monitored in the Lower Mondego region (Portugal). For this purpose, Sentinel-2 satellite data were explored enabling us to follow spatial patterns in three water channels from 2018 to 2021. By applying a straightforward and effective methodology, it was possible to estimate areas that could contain water hyacinth and to obtain the total surface area occupied by this invasive species. The normalized difference vegetation index (NDVI) was used for this purpose. It was verified that the occupation of this invasive species over the study area exponentially increases from May to October. However, this increase was not verified in 2021, which could be a consequence of the adopted mitigation measures. To provide the results of this study, the methodology was applied through a semi-automatic geographic information system (GIS) application. This tool enables researchers and ecologists to apply the same approach in monitoring water hyacinth or any other invasive plant species in similar or different contexts. This methodology proved to be more effective than machine learning approaches when applied to multispectral data acquired with an unmanned aerial vehicle. In fact, a global accuracy greater than 97% was achieved using the NDVI-based approach, versus 93% when using the machine learning approach (above 93%). |
first_indexed | 2024-03-09T15:56:21Z |
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id | doaj.art-4ba9996b576247fc83dfc980c6767ecd |
institution | Directory Open Access Journal |
issn | 2223-7747 |
language | English |
last_indexed | 2024-03-09T15:56:21Z |
publishDate | 2022-12-01 |
publisher | MDPI AG |
record_format | Article |
series | Plants |
spelling | doaj.art-4ba9996b576247fc83dfc980c6767ecd2023-11-24T17:27:44ZengMDPI AGPlants2223-77472022-12-011124346510.3390/plants11243465Spatio-Temporal Water Hyacinth Monitoring in the Lower Mondego (Portugal) Using Remote Sensing DataLuís Pádua0Lia Duarte1Ana M. Antão-Geraldes2Joaquim J. Sousa3João Paulo Castro4Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, PortugalInstitute of Earth Sciences, FCUP Pole, Rua do Campo Alegre, 4169-007 Porto, PortugalCentro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança Campus de Santa Apolónia, 5300-253 Bragança, PortugalEngineering Department, School of Science and Technology, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, PortugalCentro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança Campus de Santa Apolónia, 5300-253 Bragança, PortugalMonitoring invasive plant species is a crucial task to assess their presence in affected ecosystems. However, it is a laborious and complex task as it requires vast surface areas, with difficult access, to be surveyed. Remotely sensed data can be a great contribution to such operations, especially for clearly visible and predominant species. In the scope of this study, water hyacinth (<i>Eichhornia crassipes</i>) was monitored in the Lower Mondego region (Portugal). For this purpose, Sentinel-2 satellite data were explored enabling us to follow spatial patterns in three water channels from 2018 to 2021. By applying a straightforward and effective methodology, it was possible to estimate areas that could contain water hyacinth and to obtain the total surface area occupied by this invasive species. The normalized difference vegetation index (NDVI) was used for this purpose. It was verified that the occupation of this invasive species over the study area exponentially increases from May to October. However, this increase was not verified in 2021, which could be a consequence of the adopted mitigation measures. To provide the results of this study, the methodology was applied through a semi-automatic geographic information system (GIS) application. This tool enables researchers and ecologists to apply the same approach in monitoring water hyacinth or any other invasive plant species in similar or different contexts. This methodology proved to be more effective than machine learning approaches when applied to multispectral data acquired with an unmanned aerial vehicle. In fact, a global accuracy greater than 97% was achieved using the NDVI-based approach, versus 93% when using the machine learning approach (above 93%).https://www.mdpi.com/2223-7747/11/24/3465satelliteinvasive speciesnormalized difference vegetation indexremote sensinggeographical information systems |
spellingShingle | Luís Pádua Lia Duarte Ana M. Antão-Geraldes Joaquim J. Sousa João Paulo Castro Spatio-Temporal Water Hyacinth Monitoring in the Lower Mondego (Portugal) Using Remote Sensing Data Plants satellite invasive species normalized difference vegetation index remote sensing geographical information systems |
title | Spatio-Temporal Water Hyacinth Monitoring in the Lower Mondego (Portugal) Using Remote Sensing Data |
title_full | Spatio-Temporal Water Hyacinth Monitoring in the Lower Mondego (Portugal) Using Remote Sensing Data |
title_fullStr | Spatio-Temporal Water Hyacinth Monitoring in the Lower Mondego (Portugal) Using Remote Sensing Data |
title_full_unstemmed | Spatio-Temporal Water Hyacinth Monitoring in the Lower Mondego (Portugal) Using Remote Sensing Data |
title_short | Spatio-Temporal Water Hyacinth Monitoring in the Lower Mondego (Portugal) Using Remote Sensing Data |
title_sort | spatio temporal water hyacinth monitoring in the lower mondego portugal using remote sensing data |
topic | satellite invasive species normalized difference vegetation index remote sensing geographical information systems |
url | https://www.mdpi.com/2223-7747/11/24/3465 |
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