THE COLLECTING OF GROUNDWATER BY THE QANATS: A MILLENNIUM TECHNIQUE DECAYING

Abstract

On the Iranian origin, technical qanats are an ancestral hydraulic system is to capture and drain the water from groundwater to the gardens. 3000 years old, this technique has allowed man to move from a system of water collection based on animal or human effort a low performance a system of underground galleries that drains the groundwater to the surface of soil without effort and with high efficiency. The present study shows that the technique of qanats under different appellations (foggaras, Qanat Khettara, Falaj ...) was performed in 52 arid and semi-arid. Unfortunately, this technique was originally development of several oases, is currently in a degraded state. There are approximately 33000 galleries service a total of 85000 in twelve countries, operational estimated percentage to 38%. The reasons for this decline are environmental and socio-economic type.