Investigating long year gully erosion and its impacts on soil loss, land
competition and crop yield reduction, north-west Ethoipia
Abstract
This paper investigated the rate of gully formation and development, and
its impacts on land competition and crop yield reduction in the Genbo
Wonz Watershed, north-west highlands of Ethiopia. Geometrical gully
dimension measurements, field observations and satellite imagery
assessment have been performed selecting 22 gullies. As a result, road
construction and design problems of soil and water conservation
practices (SWCPs) were found to be important causes of gully formation
and development. The total volume of soil loss from 22 gullies in three
decades was ~340, 957 t, changing ~10 ha
agricultural land to unproductive land. The annual rate of gully erosion
was found to be ~62 t ha-1 with an average gully density
of 16.4 m ha-1. Gully erosion also results in loss of 24 t yr-1 Teff
grain yield (Eragrostis teff, E. abysainica) and 14 t yr-1 animals
forage. To arrest the problem, proper design of SWCPs within farmlands,
appropriate runoff discharge mechanisms along roads and controlled
grazing systems within the grazing lands ought to be executed.