Using GIS and remote sensing to assess the past trends in land use/cover change in Ahafo Ano north district, Ghana

An attempt was made to evaluate land use/cover change trajectory in Ahafo Ano North District for a period of thirty-three years (33) using remote sensing (RS) and GIS. The study used multi-spectral satellite data obtained from Landsat-5, Landsat-7 and Landsat-8. Supervised classification through maximum classification algorithm was used for image classification. Post-classification algorithm was employed to detect changes. The 33-year study reveals that substantial change has occurred in the study watershed. Between 1986 to 2002, farm land changed to built-up, forest and shrub by 802.2-ha, 2174.9-ha and 1431.6-ha, respectively. Forest changed to built-up, farm land and shrub land by 471.4-ha, 4697.4-ha and 8220.7-ha respectively. Shrub land changed to built-up, farm land and forest by 218.6-ha, 4523.6-ha and 16608.2-ha, respectively. While at the same time, built-up changed to farm land, forest and shrub land by 32.0-ha, 10.5-ha and 49.3-ha, respectively. Between 2002 to 2019, it appeared that farm land changed to built-up, forest and shrub land by 1176.9-ha, 145.7-ha and 3906.9-ha, respectively. Built-up changed to farm land, forest and shrub land by 507.5-ha, 76.9-ha and 192.3-ha respectively. Shrub land changed to built-up, farm land and forest by 306.3-ha, 4388.9-ha and 9822.9-ha respectively. Between the same period, forest changed to built-up, farm land, and shrub land by 376.2-ha, 4924.1-ha and 12976.7-ha, respectively. The changes from-and-to that occurred in the land classes indicate the dynamic state in the study area, and it is strongly recommended that sustainable land utilization measures are established to avert future changes and associated landscape damage amid different land use systems. The study strongly suggests further study in future potential areas for farm land expansion in the study area. Key words: Ghana, GIS, land use/cover, Remote sensing