The subsurface occurrence of ground water can be divided into two zones (Fig. 4.1): (i) Vadose zone or unsaturated zone or zone of aeration, and (ii) Phreatic zone or saturated zone or zone of saturation. In the saturated zone, all pores or voids are filled with water, whereas in the unsaturated zone, pores contain gases (mainly air and water vapours) [...]
This article throws light upon the four regulating devices generally used for controlling water reservoirs. The regulating devices are: 1. Flashboards and Stop-Logs 2. Vertical Lift Gates 3. Radial Gates 4. Drum Gates. 1. Flashboards and Stop Logs: Flashboards and stop logs raise the reservoir storage level above a fixed spillway crest level when the spillway is not required to [...]
Canal outlets are of the following three types: 1. Non-Modular Outlets 2. Semi-Modular Outlets 3. Modular Outlets. Type # 1. Non-Modular Outlets: In non-modular canal outlets, discharge capacity depends on the difference of water levels in the distributary and the watercourse. The discharge through non- modular outlets fluctuates over a wide range with variations in the water levels of either [...]