Relating the land-use changes to the invasion of Pneumatopteris afra in Nigeria using remote sensing
2020
Zakaria Rahmad) | Akomolafe, Gbenga Festus
The study aimed at using satellite remote sensing in identifying the land-use changes that have occurred in Lafia, Nigeria within the past 35 years, especially in relation to the current and the predicted future invasion of a fern (Pneumatopteris afra). Landsat satellite images OLI/TIRS, ETM+ and TM within the interval of 15 years from 1985 to 2020 were used for the extraction of land-use. Six broad classification systems were used to classify the land-use changes by employing a supervised classification technique. In 1985, the bare land dominated the land-use having an area of 69156 ha while the wetland was the least having an area of 3412 ha. However, in 2020, the built-up area has dominated the land-use of Lafia with an area of 144645 ha (52.21%) while the wetland still remained the least with area of 1477 ha. This is obviously due to the geometric increase in the urbanization of this city. There was a consistent loss of the forests from 1985 to 2020 with an annual rate of loss of 0.46%. This resulted in a loss of 44329 ha of forests in 2020 out of the 47643 ha in 1985. This approximately leads to a total loss of 172,732,045 USD of forest products. The current invasion of Pneumatopteris afra in Lafia was found to fall within the shrub and grasses land-use class. This indicates that the landsat satellite could not detect the wetlands where the plant dominated due to its massive covering. This study calls for immediate conservation of the remaining forests and wetlands in Lafia to prevent further encroachments and invasion by plants.
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