Abstract

Over the years, the Volta River Basin has undergone significant changes in diverse ways. Human activities such as farming and infrastructure development as well as afforestation projects have led to changes in the land cover. The objective of this study was to monitor land cover change within 6 km buffer of the Volta Lake. The shapefile of the study area was co-registered with the Land sat images. Hybridized classification of multi-temporal images was carried out based on unsupervised classification, Normalized Difference Vegetation Index (NDVI), visualization of true/false color composite as well as local knowledge from ground truthing. Readings were taken for 50 geographical positions and corresponding classes of vegetation for estimating classification accuracy. Overall accuracy for the classified 2013 ETM+ image was 88.42%. The results revealed a significant increase in the surface area of the Volta Lake from 4173.34 km² in 1985 to 5052.99 km² in 2013. An increase of dense vegetation from 367.06 km² in 1985 to 1035.07 km² in 2013 and a significant decrease is sparse vegetation from 3604.71 km² in 1985 to 2784.01 km² in 2013 were revealed. However, when sparse and dense vegetation was considered as one class, an overall decrease of 152.69 km2 was obtained. Areas with virtually no evidence of vegetation increased from 2029.93 km² in 1985 to 1303.08 km2 in 2013.

Keywords:

Image classification, land cover, NDVI, vegetation, volta lake,

References

Competing interests

The authors have no competing interests.

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The authors have no competing interests.