African Journal of Environmental Science and Technology Vol. 1 (3), pp. 049-052 October, 2007 Available online at http://www.academicjournals.org/AJEST ISSN 1996-0786 © 2007 Academic Journals Full Length Research Paper Regional scaled mapping of gully erosion sensitivity in Western Kenya Yusuke Katsurada Nagoya University Museum, Furo-cho, Chikusa-ku, Nagoya 464-8601 Japan. E-mail:
[email protected]. Tel.: +81-52-789-2527. Accepted 30 August, 2007 East African Rift regions suffer from serious gully erosion. As a preliminary step to assess gully erosion and to establish appropriate managements of geological/geomorphological conditions of the East African Rift escarpments, slope gradient, vegetation coverage, and sediment hardness in western Kenya, were used as mapping factors and overlayed to create separate channels in RGB color space. Pixels highlighted in this mapping can be considered as indicators of sediment erosion potential and runoff sensitivity of igneous rocks. The precision of the model for gully erosion sensitivity may be improved by including soil properties and topographic information. Key words: Gully erosion, East African Rift, Kavirondo Rift, Lake Victoria basin, GIS, remote sensing, RGB color space. INTRODUCTION Geology and topography in the East African Rift regions absorb some of the energy of raindrops and running are characterized by the large elevation differences and water, and also contribute mechanical strength of the soil the occurrence of Precambrian basement rocks and (Morgan, 1995). Miocene volcanic rocks. There are basins with Quarter- Final target of the study is to assess the gully erosion nary deposits within the bottom of the rift grabens.