Economical evaluation and comparing gravitational systems and the systems which are under the pressure of water distribution network in Sistan region

Based on the transferring conduit, the irrigation method, can be classified into two groups, one of these groups is the exposed method and the other one is the closed channel, based on the energy providing methods the conduit can be categorized into the groups of gravity flow and under pressure flow. The usage of different channels in transferring and distribution is categorized under the gravity or exposed methods, which include the channels which were constructed by embankment, or the forming of pre-constructed sections by different materials and in the exposed form. If by applying gravity flow (without pumping) and using pipes and the vessels of underground pelages, the flow of water become less than 10 meters, then that transferring and distribution method will be called as the low pressure method. The construction of watering installations is very costly, therefore lack of attention toward the correct utilization of water not only doesn’t provide the predicted benefits from these installations, but also in a general scale it can destroy the environment of the primary assets. In this research the irrigation and drainage network of Sistan region, which is one of the most sensitive and strategically regions in Iran is investigated and the sufficient solutions are presented. This region is facing the crisis of water. The studied results indicate that the most common technical problems in networks are the distribution of channel coverage in different forms, insufficient performance of the water adjustment and distribution systems and the low efficiency of networks. The obtained results from the economical evaluation indicate that water transferring by tubing system has more economical justification than the system of transfer-ring water by exposed channels.

Keywords:

Exposed channel , closed channel , irrigation and drainage , technical issues , economical evaluation , linear programming