Clean technology for alternative irrigation systems

In many countries of the Mediterranean basin, Near and East Asia, as well as in some parts of Central and South America, the so-called "hydraulic noria", one of the categories of water-wheels, has represented a significant ecological system which has played a leading role in solving the main problem of supplying and carrying water for irrigation. This typology, based on the best employment of the power of the river, is a clean technology for the environment with easy and low-cost maintenance requirements. This paper analyses some different and significant typologies still in use in Syria, East Asia and Central America, focusing on their architectural aspects, ecological characteristics and identifying differences, advantages and disadvantages, by examining the shape and design of the wheels.