Monitoring spatial-temporal variations of surface areas of small reservoirs in Ghana’s Upper East Region using Sentinel-2 satellite imagery and machine learning

Small reservoirs are one of the most important sources of water for irrigation, domestic and livestock uses in the Upper East Region (UER) of Ghana. Despite various studies on small reservoirs in the region, information on their spatial-temporal variations is minimal. Therefore, this study performed...

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Autores principales: Ghansah, B., Foster, T., Higginbottom, T. P., Adhikari, R., Zwart, Sander J.
Formato: Journal Article
Lenguaje:Inglés
Publicado: Elsevier 2022
Materias:
Acceso en línea:https://hdl.handle.net/10568/117314
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author Ghansah, B.
Foster, T.
Higginbottom, T. P.
Adhikari, R.
Zwart, Sander J.
author_browse Adhikari, R.
Foster, T.
Ghansah, B.
Higginbottom, T. P.
Zwart, Sander J.
author_facet Ghansah, B.
Foster, T.
Higginbottom, T. P.
Adhikari, R.
Zwart, Sander J.
author_sort Ghansah, B.
collection Repository of Agricultural Research Outputs (CGSpace)
description Small reservoirs are one of the most important sources of water for irrigation, domestic and livestock uses in the Upper East Region (UER) of Ghana. Despite various studies on small reservoirs in the region, information on their spatial-temporal variations is minimal. Therefore, this study performed a binary Random Forest classification on Sentinel-2 images for five consecutive dry seasons between 2015 and 2020. The small reservoirs were then categorized according to landscape positions (upstream, midstream, and downstream) using a flow accumulation process. The classification produced an average overall accuracy of 98% and a root mean square error of 0.087 ha. It also indicated that there are currently 384 small reservoirs in the UER (of surface area between 0.09 and 37 ha), with 20% of them newly constructed between the 2016-17 and 2019-20 seasons. The study revealed that upstream reservoirs have smaller sizes and are likely to dry out during the dry season while downstream reservoirs have larger sizes and retain substantial amounts of water even at the end of the dry season. The results further indicated that about 78% of small reservoirs will maintain an average of 54% of their water surface area by the end of the dry season. This indicates significant water availability which can be effectively utilized to expand dry season irrigation. Overall, we demonstrate that landscape positions have significant impact on the spatial-temporal variations of small reservoirs in the UER. The study also showed the effectiveness of remote sensing and machine learning algorithms as tools for monitoring small reservoirs.
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spelling CGSpace1173142025-10-26T13:02:11Z Monitoring spatial-temporal variations of surface areas of small reservoirs in Ghana’s Upper East Region using Sentinel-2 satellite imagery and machine learning Ghansah, B. Foster, T. Higginbottom, T. P. Adhikari, R. Zwart, Sander J. reservoirs remote sensing climate variability satellite imagery machine learning Small reservoirs are one of the most important sources of water for irrigation, domestic and livestock uses in the Upper East Region (UER) of Ghana. Despite various studies on small reservoirs in the region, information on their spatial-temporal variations is minimal. Therefore, this study performed a binary Random Forest classification on Sentinel-2 images for five consecutive dry seasons between 2015 and 2020. The small reservoirs were then categorized according to landscape positions (upstream, midstream, and downstream) using a flow accumulation process. The classification produced an average overall accuracy of 98% and a root mean square error of 0.087 ha. It also indicated that there are currently 384 small reservoirs in the UER (of surface area between 0.09 and 37 ha), with 20% of them newly constructed between the 2016-17 and 2019-20 seasons. The study revealed that upstream reservoirs have smaller sizes and are likely to dry out during the dry season while downstream reservoirs have larger sizes and retain substantial amounts of water even at the end of the dry season. The results further indicated that about 78% of small reservoirs will maintain an average of 54% of their water surface area by the end of the dry season. This indicates significant water availability which can be effectively utilized to expand dry season irrigation. Overall, we demonstrate that landscape positions have significant impact on the spatial-temporal variations of small reservoirs in the UER. The study also showed the effectiveness of remote sensing and machine learning algorithms as tools for monitoring small reservoirs. 2022-02 2021-12-31T22:36:33Z 2021-12-31T22:36:33Z Journal Article https://hdl.handle.net/10568/117314 en Open Access Elsevier Ghansah, B.; Foster, T.; Higginbottom, T. P.; Adhikari, R.; Zwart, Sander J. 2022. Monitoring spatial-temporal variations of surface areas of small reservoirs in Ghana’s Upper East Region using Sentinel-2 satellite imagery and machine learning. Physics and Chemistry of the Earth, 125:103082. [doi: https://doi.org/10.1016/j.pce.2021.103082]
spellingShingle reservoirs
remote sensing
climate variability
satellite imagery
machine learning
Ghansah, B.
Foster, T.
Higginbottom, T. P.
Adhikari, R.
Zwart, Sander J.
Monitoring spatial-temporal variations of surface areas of small reservoirs in Ghana’s Upper East Region using Sentinel-2 satellite imagery and machine learning
title Monitoring spatial-temporal variations of surface areas of small reservoirs in Ghana’s Upper East Region using Sentinel-2 satellite imagery and machine learning
title_full Monitoring spatial-temporal variations of surface areas of small reservoirs in Ghana’s Upper East Region using Sentinel-2 satellite imagery and machine learning
title_fullStr Monitoring spatial-temporal variations of surface areas of small reservoirs in Ghana’s Upper East Region using Sentinel-2 satellite imagery and machine learning
title_full_unstemmed Monitoring spatial-temporal variations of surface areas of small reservoirs in Ghana’s Upper East Region using Sentinel-2 satellite imagery and machine learning
title_short Monitoring spatial-temporal variations of surface areas of small reservoirs in Ghana’s Upper East Region using Sentinel-2 satellite imagery and machine learning
title_sort monitoring spatial temporal variations of surface areas of small reservoirs in ghana s upper east region using sentinel 2 satellite imagery and machine learning
topic reservoirs
remote sensing
climate variability
satellite imagery
machine learning
url https://hdl.handle.net/10568/117314
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