Statement (I): The trap efficiency of a reservoir increases with
Statement (I): The trap efficiency of a reservoir increases with age as the reservoir capacity is reduced by sediment accumulation.
Statement (II): The trap efficiency is a function of the ratio of reservoir capacity to the total inflow. A small reservoir on a large stream has a low trap efficiency.A. Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
B. Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)
C. Statement (I) is true but Statement (II) is false
D. Statement (I) is false but Statement (II) is true (II) is true
Please scroll down to see the correct answer and solution guide.
Right Answer is: D
SOLUTION
Trap efficiency of a reservoir is the ratio of total sediments retained by reservoir to the total sediments entering into reservoir (inflow sediments).
Trap efficiency of reservoir is the function of ratio of reservoir capacity and total inflow.
Factors affecting the trap efficiency:
1. Reservoir Capacity or sediments deposition: The reservoir capacity is inversely related to the amount of sediments deposited. As the time passes, rate of silting or rate of deposition of sediments reduces but amount of sediments deposited will be increased which in turn reduces the capacity of reservoir. Hence, trap efficiency also gets reduced. (Statement – I is False)
2. Size of reservoir and stream: A larger reservoir on small stream has less capacity inflow ratio and hence having higher trap efficiency.
3. Velocity of flow of stream: Higher velocity less deposition of sediments, lower is the trap efficiency.