Assessing Land Use / Land Cover Changes Using GIS and Remotely Sensed Techniques (RST): A Case Study of the Etoa Clay Quarry Yaounde, Cameroon

This study highlights the use of Remote Sensing to detect environmental changes obtained on Land Use / land Cover Changes in the Etoa clay quarry, neighboring the town of Yaounde (Cameroon) during a period of 26 years .Remotely sensed data in the form of Landsat image and pattern classification were used to create maps.For accuracy Google Earth was used as a reference to yield data.The post classification change detection method was used to value the land cover change with the clay quarry.Land use of the urban growth was estimated by time series analysis of satellite Landsat images.Spectral indices calculated from the images were used to evaluate change in buildup area, vegetation and hydrology.Results show that vegetation, covers 200 hectares of land, build up area 240 hectares and hydrology 185 hectares.The change analysis between 1989-2015 showed a decreasing trend in vegetation from 69% to 32% (a decrease in 37% vegetation cover), hydrology from 14% to 30% (thus a 16% increase in water bodies) and build up area from 17% to 38% (a 21% increase).The excavation of clay materials increases every year leaving behind many dangerous clay pits filled with water which calls for concern.