Abstract

Omolara ayefele, Isaiah Ogunde and Jude Akpodeta

This study was carried out in one of the local government areas in the southwestern part of Nigeria. Its aim is to highlight the causes and characteristics of gullies, and their effects in the area. Gullies in the local government headquarter; the most developed area, and three other rural areas; with varying degree of rurality were studied. Measurements were done in the dry season, at intervals of 10 m (less where gully length was shorter than 20 m) using convectional surveying equipments. Mean gully depths measured at gully shoulders were obtained at the beginning, middle and end of cross-sections. A total of 14 gullies were studied; 8 at Ode Irele (LGA Hq), 4 at Akotogbo, and 1 each from Ajagba and Lipanu. The gullies at Ode-Irele were significantly different from others, especially in terms of the length and width (p< 0.05). In addition while Order 1 gully system dominated study area, an Order 3 and two Order 2 gullies were cited in Ode – Irele. The study concluded that unsustainable development is a complementary agent of erosion in the built up area, in addition to the soil characteristics that has been identified by similar study in the southeastern Nigeria. The study attributed the aggravation of gully process in built – up environments.