An irrigation system for domestic vegetable gardens: application to a case study of subsistence farming in Madagascar

In 2021 the lack of safe water for the human being needs is still an issue, especially in the developing countries. To overcome this problem, the United Nations establish the SDG 6 “Ensure availability and sustainable management of water and sanitation for all” with the purpose to give safe water to all the people in need within 2030. The present work follows the purpose of the Goal 6 and it focuses on the case study of the Nosy Mitsio island in the North of Madagascar. In the island the local population suffers the absence of a water supply system for irrigation of vegetable gardens: for now, the locals practice a subsistence farming, changing the location of the vegetable gardens when the soil loses its fertility and stopping the farm during the dry season. With this method, the population is unable to sustain itself with the vegetables of the gardens which are not constantly produced, and their stocks are insufficient for the entire population. With the aim to design a basic water supply system, different aspect about the island have been investigated: first of all, both the social and economic situation and the water facilities present on the island have been studied. On the other hand, data about the weather and the hydrogeological characterization have been collected, in order to create a literature data about the island. Thanks to an expedition on Nosy Mitsio, it has been possible to study the result of water sample analysis and performing laboratory test on soil samples. At least, a simple water supply system has been designed, to bring water from the selected spring to the area addressed to the gardens, finding the best configuration to assure the required irrigation water amount. This work has been carried out thanks to the partnership between the Politecnico di Torino, the Onlus H4O Help for Optimism, and the Onlus Kukula. Working on a project on international cooperation during the Covid 19 pandemic has given rise to a new way of working together, where the mutual exchange of information between different parties and the help of the local population is crucial to overcome the impossibility to go on the site.