Assessment of surface irrigation potential and crop water requirement: the case of Megech watershed, Upper Blue Nile Basin, Ethiopia

• Published in: Sustainable water resources management 2022-08, Vol.8 (4), Article 92
• Main Authors: Fikadie, Fitamlak T., Wubneh, Melsew A., Kifelew, Mekash S., Sinshaw, Birhanu G.
• Format: Article
• Language: English
• Subjects: Agricultural land; Agricultural resources; Decision making; Developing countries; Development Economics; Dry season; Earth and Environmental Science; Earth Sciences; Flow duration; Flow duration curves; Food production; Geographical information systems; Hydrogeology; Hydrology/Water Resources; Irrigable land; Irrigable lands; Irrigated lands; Irrigation; Irrigation water; Land resources; LDCs; Low level; Matrix methods; Minimum flow; Original Article; Rainy season; River discharge; River flow; Rivers; Storage; Stream flow; Surface irrigation; Sustainable Development; Water discharge; Water Policy/Water Governance/Water Management; Watersheds; Wet season
• ISSN: 2363-5037; 2363-5045
• DOI: 10.1007/s40899-022-00690-5

For the world’s growing population, large improvements in food production are required. The majority of newly irrigated land will come from developing countries. Ethiopia has a substantial agricultural land resource. About 66% of the country’s area is potentially appropriate for agriculture, but only 5% of this area has been developed. To examine the fundamental causes of this low level of irrigation development, land suitability for irrigation was estimated using pair-wise comparison matrix methods and arc GIS-based weighted overlay techniques, which consider the collaboration of ten factoring parameters. The results indicated that 5.6% of the area is highly suitable, 68.2% moderately suitable, 26.1 marginal suitable, and 0.1% were unsuitable for surface irrigation. To grow in these identified irrigable areas, seven crops were selected, and their gross irrigation demand was calculated using CROPWAT8.0. The discharges at the site of interest were estimated by transferring the river discharge at the gauged site to the site of interest on the same river using area ratio methods. The surface available flow was determined by generating a flow duration curve at Q-90% minimum flow, the estimated result is 0.044m 3 /s. By associating the gross irrigation demand of irrigable land with the available flow in rivers, the total surface irrigation potential of the study area was obtained as 181 ha. The river flow during the dry season is not sufficient for targeted irrigation sites. As the result revealed that the available dry river flow does not meet the available potential irrigable land, hence the government and decision-makers should plan storage structures that collect flow in the wet season for dry irrigation.