Investigation the effects of muddy water in decreasing seepage in the transition channels (Case study: Ferdows, South Khorasan province)

Water of Baladeh's qanats travels around 15 Kilometers to arrive the lands in Ferdows by a channel. Farmers in order to reduce seepage in transition channels try to make the water muddy. In this research, with measuring seepage in both muddy water and pure water channels, the effects of making muddy water in seepage are investigated. The Seepage in channel 1 and 2 is measured by inflow-outflow test. Noticed that pondage test is employed for channel 3. The results show that making muddy water in a 16 hours period can reduce seepage around 60-67 percent. Also with continuing in making muddy water and controlling the erosion, seepage can be decreased approximately 95 percent. Loss of water in entrance of the channels is twice of the value in channels bed. Also muddy water can decrease seepage around 95 percent in sealing of pores in intake valves. Nowadays the most significant effect of turbid water in Baladeh qanats is closing the output pores of valves.