Quantifying Recent Floodplain Vegetation Change along the White Volta River in the Northern Region of Ghana

Abstract

Floodplains are among the most productive and highly diverse ecosystems that serve as a source of feed, shelter and breeding ground for wildlife, as well as protect neighbouring settlements from flush floods. Nonetheless, they are among the most threatened habitats on earth. The study quantified factors that accounted for floodplain vegetation change of the White Volta River, in the Northern Region of Ghana. We used Landsat images, extracted population and climate data and undertook vegetation and soil assessment. Our results showed that agricultural expansion, population growth and climate change, were the main factors that transformed the vegetation over the 26 –year period. Air temperature significantly increased from 34 ºC in 1989 to 36.1 ºC in 2010, with +0.2ºC decadal rate of change. Extreme temperatures coincided with a drop in rainfall from 1,427.3 mm to 695.5 mm/year. Agriculture expansion from 10.33% to 58.84% (1989 – 2015), led to increase in bare surface/sediment deposits (9.52% to 20.7%), while simultaneously reduced surface area of water bodies (7.61% to 3.5%) and riparian vegetation (72.53% to 16.96%). These findings highlight the current impact of climate change and human-led activities on the vegetation of the White Volta river floodplains, and suggest the need for strict conservation measures to curb further depletion of the vegetation and restore its overall functional status.