灌漑・排水システム工学

Irrigation would provide farmers with sustained livelihoods and improve their general well-being. The aim of this study was to evaluate the suitability of the land for surface irrigation using GIS based weighted overlay analysis of individual parameters for better utilization of land resources. Factors considered included physical land features (land use/land cover, soil and slope), and proximity to water sources. Based on soil depth, 82.4% of the study area is potential suitable for the intended uses; the drainage class scores 70% suitability; 80% the soil texture was clay dominant hence it was moderately suitable for surface irrigation. Considering the terrain, 11.75% of the basin is suited for irrigation practice. The LULC classification revealed that, 54.42% was found to be highly suitable and 16.7% is found to be unsuitable. In reference to river proximity, around 81% of the area could be highly recommended for the intended use. Excluding the national parks, 71% (7% is S1 and 64% is S2) is suitable for the intended use. Hence, future surface irrigation development is feasible. Based on the findings, to increase the land area to be irrigated; an appropriate drainage provision and cost wise land leveling should be taken into consideration, further land suitability analysis for other types of irrigation and water source should be carried out. The study result could assist policy makers for better decisions during the development of irrigation projects in Omo-Gibe river basin.

The article considers the flow efficiency and operational reliability of large canals. In order to raise efficiency and reliability of exploitation of canals hydraulic control model to change the flow depth was created. It was determined by the law of water transmission in optional time. Patterns based on determination of hydraulic relations under changing values of hydraulic parameters of water flow in the trapezoid cross-section irrigation canal were examined.