Abstract
The assessment process of surface irrigation has to integrate information about the suitability of the land; water resource availability and water requirements of irrigate able areas in time and place. Birbir River is one of well-known river found in western Ethiopia. The Birbir River is a tributary of the Baro-Akobo river basin, which creates Baro River when it joins with Gebba River. Ethiopia has immense potential in expanding irrigation using available water resources. But due to lack of information related to cultivable and irrigation suitability of the land, its agricultural system does not yet fully productive. Geographic Information System can be an effective tool in identifying irrigable land and mapping of suitable land for irrigation. Therefore, the objective of the present study was to assess the surface irrigation potential of the Birbir river watershed using ArcGIS 10.3. Different methods of data processing and analysis have been employed in this study. The main suitability factors used to identify the potential irrigable land for surface irrigation were slope, soil texture, soil depth, soil type, soil drainage characteristics, land use, land cover and distance to water source. The consistency of rainfall and stream flow data were checked by double mass curve and the areal mean of rainfall and temperature data were determined by using Theissen polygon method whereas the irrigation water demands of the selected two crops (maize and potato) were calculated separately using FAO cropwat model. By weighting values of the seven factors using Analytic Hierarchy Process and overlaying by weighted overlay in ArcGIS 10.3, the irrigation suitability map was developed and potential irrigable land for surface irrigation was found to be 17%, 63% and 20% for highly suitable (S1), moderately suitable (S2), and marginally suitable (S3) respectively. Irrigation potential of the Birbir river watershed was obtained by comparing monthly gross irrigation requirements of the identified land suitable for surface irrigation and the available 80% mean monthly dependable flows in the river catchments. The potential irrigable land that can be irrigated without provision of storage structures was found to be around 68,000 ha from the total of 106,223 ha suitable land for surface irrigation.
Highlights
IntroductionToday's world population of 7.6 billion is expected to reach about 11.1 billion by the end of 2100
The remaining 27.25% (171048 ha) of the total area of the Birbir river watershed was found to be in the range of marginally suitable (S3) for surface irrigation system with respect soil texture suitability
About two third of the watershed which is 62.92% (392232 ha) was found to be in the range of moderately suitable (S2) for surface irrigation system, were as the remaining 20.05% (124947 ha) of the total area of the Birbir river watershed was found to be in the range of marginally suitable (S3) for surface irrigation system
Summary
Today's world population of 7.6 billion is expected to reach about 11.1 billion by the end of 2100. This growing population will result in considerable additional demand for food [1]. FAO analyzed agricultural production for over 90 less developed country, and the result showed that from a period of 1998 to 2030 it increases by 49% in rain-fed agriculture and by 81% by irrigation. A higher number of additional foods are expected from an irrigation system [2]. Agriculture is the basis for the economy of Ethiopia. Agriculture accounts for the employment of 90% of country’s population, over 50% of the country’s gross domestic product (GDP) and over 90% of foreign exchange earnings [4]. About 15 to 17% of Garuma Negasa: GIS-Based Irrigation Potential Assessment for Surface Irrigation: The Case of Birbir River Watershed, Oromia, Ethiopia
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
