Since my first field surveys in Western Asia (1956) I have been involved in many missions to Asia, Africa and the Americas which were organized by national or international academic institutions. During these missions I have found my life work: the comparative study of the foggara oasis of the arid zone of the old continent. The main case studies outlined in this paper were carried out in North Africa, Western Asia and China. In 1962, at the UNESCO Crete Symposium, I had an excellent opportunity to receive critical advice for my topics from distinguished dryland scientists.
Although the foggara system is globally distributed, we recognize the imbalance of quality through these case studies. For example in Iran, several case studies were carried out by western scholars in the 1950s but the subject was given little attention from Iranian authorities. Because of the rapid growth of the urban population, Iranians began to change their water system from traditional hydro-technology, such as the qanat system, to modern pumping wells. However, in the last ten years, they have recognized the positive contribution of traditional technology from the point of energy-saving aspects and sustainability of the system. The main topics for combating desertification designated by UNCCD include the usefulness of traditional technology. UNESCO together with the Iranian government supported the establishment of the International Qanat Research Center in Yazd in 2005, and in 2004 the European Commission started a three-year project on foggara in North Africa. This paper explains the changes occurring in foggara oases in the last fifty years based on my field studies.