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.

This article summarizes the different local construction materials observed in two regions of Cameroon (Adamawa and NorthWest). These raw materials were mapped and evaluated using various methods of investigation (spatial distribution, estimation of reserves, development of a database compatible with geo-referenced maps). The results obtained show three types of local construction materials (vegetal, pedological and geological) with quantitative estimation or distribution. Vegetal local materials include herbaceous savanna with strong dominance of straw in Adamawa region than the North West region. Pedological local construction materials include lateritic soils (ferruginous or clayey), harplan, sandy clay and sandy clay soil while geological local construction materials include volcanic, plutonic and metamorphic rocks. Many sites of these geological materials are suitable for the rock quarry plant. Adamawa region also contains sedimentary rocks constituted by metamorphic conglomerate and sandstones. Two main types of residential homes are constructed with these local construction materials in these regions of Cameroon. These include huts and houses.