Changes

The water-powered noria uses the same principle as the Persian wheel and therefore also needs to be of larger diameter than the pumping head, which either limits it to very low lift pumping or requires very large, cumbersome and expensive construction. Small, low-lift norias, used in Thailand and China, are very inexpensive while much larger norias are used in Vietnam and Syria. Some of the largest in Syria exceed 10m in diameter, but in relation to their size they tend to be unproductive compared with more modern pumping systems.

==Acknowledgements==

* [http://www.fao.org/docrep/010/ah810e/AH810E05.htm REVIEW OF PUMPS AND WATER LIFTING TECHNIQUES.] Natural Resources Management and Environment Department, Food and Agriculture Organization (FAO).