|WATER STORAGE IN CISTERN-JARS
Definition characters description and diffusion
The system of the cistern-jars, underground water reserves, is spread throughout the islands and along the arid Mediterranean coasts, providing a reserve known to travellers who used it during their journeys. Herodotus reported that the Persian Emperor Cambise invaded Egypt in 525 BC crossing the desert thanks to an argreement with the Arabs who revealed to him where the cistern-jars were situated.
General characters description and diffusion
Some mysterious cistern-jars are still used in the more then 300 Dahalac isles in the Red Sea where sea nomadism is practiced. Young shepherds and their herds are transported on rafts to the deserted isles where they stay for all the period needed for grazing. The way they get water on these coral soils, completely lacking in fresh water tables, where rains are very irregular, is a sample of condensation and survival techniques used in dry environments. Open-air cisterns are built on the sandy surfaces by means of large jars, which are wholly sunken into the sand. Heaps of stones catch the atmospheric moisture that drops into the surrounding reservoir. In the prous madrepore soils, large craters carved out of the rock in a circular way have mounds of stones in the middle. Underneath, there is a water-tight cistern that is always full of clear water taken from the sea breeze through the pores in the walls of the artificial craters and miraculously appears in the pond seeping out of the rocks. The practice is useful in conditions of extreme marginality with water supply coming from the air vapours. Systems of implementation by means of modern condensers are used in the Mediterranean isles.
Advantages and sustainability
This type of water collection and storage makes human processes vital to communities possible in areas where there is not much rainfall or other water sources.