African Journal of Soil Science

African Journal of Soil Science ISSN 2375-088X Vol. 4 (3), pp. 321-327, March, 2016. © International Scholars Journals

Full Length Research Paper                      

Evaluation of the existing conservation practices on Lake Haramaya Catchment

Zerihun Asad1*, Dametew Adem1 and Abdulaziz Farah2

1Department of Soil and Water Engineering, Jigjiga University, P. O. Box 1020, Jigjiga, Ethiopia. 2Institute of Technology, Haramaya University, P. O. Box 345, Haramaya University, Ethiopia.

*Corresponding author. E-mail: zerihun_asad@gmail.com.

Accepted 09 September,  2015

Abstract

A study was carried out at Lake Haramaya Catchment (5032 ha) to evaluate soil erosion, sedimentation and conservation practices. The catchment has experienced severe degradation due to intensive cultivation, deforestation, unwise utilization of land and water resources which lead to the onset of soil erosion. The Gumbel's Method and MUSLE were employed to estimate the peak flood and catchment sediment yield respectively. SWAT was used to delineate the catchment and to analyse the catchment slope, soil and land uses. Besides, interview and field observation were carried out to collect data regarding the effects of soil erosion and status of existing conservation measures. The average annual soil loss from the study area estimated is to 24.315 ton/ha/year resulted due to the high rainfall erosivity in the area. Moreover, the results showed a direct relationship between rainfall and sediment yield. With regard to the method of soil and water conservation practices, biological conservation measures like mulching and mixed cropping are widely implemented with almost zero or negligible engineering measures. Small mechanical/engineering measures that could better hit the target are not considered. Generally, soil erosion of the catchment is high and integrated watershed management is needed to minimize the erosion problem.

Key words: Soil loss, SWAT, MUSLE, lake sedimentation, erosion, Haramaya.