Extent of Gully Erosion and Farmer’s Perception of Soil Erosion in Alalicha Watershed, Southern Ethiopia

Abstract

A study was conducted to investigate the extent and rate of gully erosion in Alalicha watershed, southern Ethiopia. Gully measurements, field observations, and interviewing were used to generate the necessary data. Two sub watersheds; Bora and Banda were delineated and 21 gullies were identified. Investigation of the morphology, age and main causes for initiation of the gullies were carried out. The result shows that, long term gully erosion rate for the watershed was 2.12 t ha-1yr-1 and the total surface area occupied by gullies in Bora and Banda sub watersheds were about 19,328.2 m2 and 6,433.2 m2 respectively. The estimated total volume of soil loss was over 36,000 m3 in Bora and 8,700 m3 in Banda sub watersheds. A gully density of 11.1 m/ha for Bara and 6.7m/ha for Banda were estimated implying variations in severity of gully erosion. Based on length, all the gullies in the watershed have categorized under long gullies; however medium deep gullies dominate (77-88%) in both sub watersheds than shallow gullies (12-23%). Analysis of the gully morphology reveals that, a negative relationship exists between the top width and depth of gully. The damages and associated problems of the gullies, as explained by farmers, include loss of land, dissection of farms, and deposition of sediments on growing crops and restriction of movement of animal and people. The farmers of the watershed were well aware of soil erosion, soil fertility loss and erosion control and fertility management methods. However reluctant to implement as, they look food incentives because of poor economic status. Hence to conserve the land primarily awareness creation and encouraging the farmers through some sort of incentive may be required. Keywords: gully erosion, gully morphology, farmers’ perception and erosion control.