This brief survey focuses on the long tradition offlood irrigation in Southern Arabia which culminatedin the famous Great Dam of Ma'rib. Its long existenceof more than one millenium proves its success. TheGreat Dam was the central part of an irrigation systemwhich covered an area of about 9600 ha, divided intoa smaller North Oasis and a larger South Oasis. Majorreasons for this successful irrigation practice arediscussed: the function of the dam as one of waterdiversion and not for storage, the simplicity of waterdistribution, the use of huge amounts of water and theimportance of a strong management.
The slow decline of the system is symbolicallydescribed in the Holy Qur'an as a single, catastrophicevent which led to the exodus of the majority of inhabitants. As a matter of fact it resulted in thealmost unique situation of an antique irrigationsystem, although out of order, being preserved in mostof its parts till modern times. It was only in theeighties that the ancient oases were cultivated again.But it was not the revival of the dam with itscorresponding irrigation scheme which changed thesituation fundamentally, but rather the opening of anearby oilfield, the completion of the asphalt roadSana'a–Ma'rib and the introduction of the dieselpump.
ecology exodus Great Dam irrigation Ma'rib Sabean Oasis