Fig. 7.

Satellite images (LANDSAT 8) of the study region showing: vertisol areas (true color images, pictures: A, B, C), the vegetation coverage (near infrared images, pictures: A.1, B.1, C.1) and vertisol areas classified images (Pictures: A.2, B.2, C.2) in different seasons. Photo A was acquired during the rainy season when the vegetation cover was dense, largely concealing the vertisols surface. Near infrared bands allows to visualize the vegetation in Red color, which accentuates the dense vegetation cover. Photos B were taken during the early dry season when seasonal vegetation had dried up but was still largely concealing the vertisol surface. Photos C were obtained during the late dry season when the vegetation coverage was relatively sparse revealing the dark vertisols. The three villages (1- Erdwayane, 2- Salamo, and 3-Dedevit) are clearly located within vertisols areas while the town of Sheraro (4) is located in sand stone area (prominently visible in 7A). In the classified images (pictures: A.2, B.2, C.2), vertisols were highlighted in yellow. In the early dry season (B.2), vertisols areas were still partially concealed by vegetation (natural and agricultural). In the late dry season (C.2), cracking vertisol areas become exposed, expanding as the vegetation cover receded posty harvest. Vertisols exposed to the sun, dry up and crack due to accelerated evaporation and subsequent shrinkage. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)