The Prevention Methods of Leak and Evaporation for Consecutive Water Reservoir

Authors have developed a practical use of the consecutive water reservoir system as a source of small scale irrigation for stable cropping in Semi-Arid Africa. Particularly in Semi-Arid Africa, it is important to prevent the losses of leak and evaporation at the water reservoirs. In this study, the prevention methods of those losses from the water reservoir were considered in semi-arid area of Central Ethiopia, where the irrigation system based on consecutive water reservoir is expected to be prevailed among small scale farmers. The consecutive water reservoir system consists of the primary, the secondary and the tertiary reservoirs. This study focuses on the tertiary reservoir since small scale farmers can afford to establish only small reservoirs sized as the tertiary reservoir. For the prevention of leak loss, it is important to analyze soil characteristics in the area and to compact soil at the optimum water content based on the Proctor’s Principle of soil compaction. In this study it was revealed that it is the most effective to compact soil when water content is 33%. For the prevention of evaporation loss, foam polystyrene was proposed as a material to cover the water surface of reservoir and it was revealed that the coverage rate of 80% is the most effective covering rate in terms of both effectiveness and efficiency.