Oxytenanthera abyssinica (A. Rich.) Munro land suitability evaluation in the Kurar watershed, Abay Gorge, Upper Blue Nile River Basin, Ethiopia

Abstract

O. abyssinica, known in Ethiopia as lowland bamboo, is a solid-stemmed clump-forming bamboo species widely distributed in the western dry regions of Ethiopia. The versatility of the species means that it has enormous potential for land restoration in arid and semi-arid areas, in addition to bringing socio-economic benefits. It also displays remarkable adaptability, allowing it to thrive in the challenging ecological conditions of areas such as the Abay Gorge. The Abay Gorge, situated within the Upper Blue Nile River Basin of Northwestern Ethiopia is characterized by problems associated with soil erosion and land degradation. This study, therefore, aimed to evaluate and recommend a suitable spatial analysis for the adoption and development of lowland bamboo (O. abyssinica). Fifteen primary influencing factors were chosen according to the needs of O. abyssinica, the accessibility of data, and the financial implications associated with data analysis, particularly the expenses related to soil laboratory testing. Eight composite soil samples were taken directly by dividing the watershed into two categories (upper and lower catchment areas). These composite soil samples were analyzed. Data analysis was performed via Analytical Hierarchy Process (AHP) in conjunction with Multi-Criteria Decision-Making (MCDM) analysis and the use of Remote Sensing (RS) and Geographic Information System (GIS). The spatial analysis employed in this study was a weighted sum overlay analysis, which was applied by considering the criteria weight assigned to each factor. The analysis revealed that 21.2 % (666.5 ha) of the total area was highly suitable for the growth and development of O. abyssinica. About 56 % (1753 ha) of the land was moderately and marginally suitable for the desired land utilization type. However, 23 % (723.8 ha) of the study area was unsuitable for O. abyssinica. O. abyssinica has the potential to rehabilitate large parts of challenging areas such as the Abay Gorge due to its naturally invase rhizomes and drought-tolerance. It can also be introduced into agroforestry systems and used as living fences for villages.