(i) Trap efficiency
- It is define the percentage of the sediment deposit in the reservoir even inspire of taking precautions and measures.
- Most of the reservoirs tap 95% to 100% of the sediment load flowing into them.
- It has not been possible to reduce the trap efficiency below about 90% inspire of several sediment control measures now know to us.
- Trap efficiency is a measure of reservoir sedimentation.
(ii) Density currents
- density current, any current in either a liquid or a gas that is kept in motion by the force of gravity acting on differences in density.
- A density difference can exist between two fluids because of a difference in temperature, salinity, or concentration of suspended sediment.
(iii) capacity- inflow ratio
- The ratio of the reservoir capacity to the total inflow of water in it is known as capacity inflow ratio.
- The percentage of sediment deposited in the reservoir even inspite of taking precautions and measures to control its deposition (trap efficiency η) is a function of capacity inflow ratio.
- For a reservoir, the capacity inflow ratio decreases with time as more sediment is deposited in the reservoir with time.
