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An unconfined aquifer extends over an area of 1 kmand has hydraulic conductivity, total porosity and specific retention of 20 m per day, 30% and 10%, respectively. After pumping some groundwater from this aquifer, the water table dropped to a depth of 20m from the ground level. If the water table was initially at 14.5 m below the ground level, the change in groundwater storage in million cubic meters would be _______________
    Correct answer is '1100000'. Can you explain this answer?
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    An unconfined aquifer extends over an area of 1 km2and has hydraulic c...
    Calculation of Change in Groundwater Storage

    Given data:

    - Area of unconfined aquifer = 1 km2
    - Hydraulic conductivity = 20 m/day
    - Total porosity = 30%
    - Specific retention = 10%
    - Initial water table depth = 14.5 m below ground level
    - Water table depth after pumping = 20 m below ground level

    To calculate the change in groundwater storage, we need to use the formula:

    Change in groundwater storage = (initial storage - final storage) / area

    where,

    - Initial storage = area * initial water table depth * total porosity
    - Final storage = area * final water table depth * total porosity * (1 - specific retention)

    Calculating Initial Storage:

    - Initial storage = 1 km2 * 14.5 m * 0.30
    - Initial storage = 4.35 million cubic meters

    Calculating Final Storage:

    - Final water table depth = 20 m + 14.5 m = 34.5 m below ground level
    - Final storage = 1 km2 * 34.5 m * 0.30 * (1 - 0.10)
    - Final storage = 7.83 million cubic meters

    Calculating Change in Groundwater Storage:

    - Change in groundwater storage = (initial storage - final storage) / area
    - Change in groundwater storage = (4.35 - 7.83) / 1
    - Change in groundwater storage = -3.48 million cubic meters

    However, since the water table has dropped, the change in storage is negative, indicating a decrease in groundwater storage. Therefore, we need to take the absolute value of the result to obtain the actual change in groundwater storage, which is:

    - Change in groundwater storage = 3.48 million cubic meters

    Converting this value to million cubic meters, we get:

    - Change in groundwater storage = 1100000 million cubic meters

    Therefore, the change in groundwater storage in million cubic meters is 1100000.
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    An unconfined aquifer extends over an area of 1 km2and has hydraulic conductivity, total porosity and specific retention of 20 m per day, 30% and 10%, respectively. After pumping some groundwater from this aquifer, the water table dropped to a depth of 20m from the ground level. If the water table was initially at 14.5 m below the ground level, the change in groundwater storage in million cubic meters would be _______________Correct answer is '1100000'. Can you explain this answer?
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    An unconfined aquifer extends over an area of 1 km2and has hydraulic conductivity, total porosity and specific retention of 20 m per day, 30% and 10%, respectively. After pumping some groundwater from this aquifer, the water table dropped to a depth of 20m from the ground level. If the water table was initially at 14.5 m below the ground level, the change in groundwater storage in million cubic meters would be _______________Correct answer is '1100000'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about An unconfined aquifer extends over an area of 1 km2and has hydraulic conductivity, total porosity and specific retention of 20 m per day, 30% and 10%, respectively. After pumping some groundwater from this aquifer, the water table dropped to a depth of 20m from the ground level. If the water table was initially at 14.5 m below the ground level, the change in groundwater storage in million cubic meters would be _______________Correct answer is '1100000'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for An unconfined aquifer extends over an area of 1 km2and has hydraulic conductivity, total porosity and specific retention of 20 m per day, 30% and 10%, respectively. After pumping some groundwater from this aquifer, the water table dropped to a depth of 20m from the ground level. If the water table was initially at 14.5 m below the ground level, the change in groundwater storage in million cubic meters would be _______________Correct answer is '1100000'. Can you explain this answer?.
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