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The volume of water drained formula calculates the amount of water that can be extracted from a soil or rock sample based on its specific yield and total volume. This is important in hydrogeology and civil engineering for understanding water storage and drainage characteristics of geological materials.
The calculator uses the formula:
Where:
Explanation: Specific yield represents the fraction of total volume that can drain by gravity, while total volume includes both solid material and pore spaces.
Details: Accurate calculation of drainable water volume is crucial for groundwater resource assessment, well design, drainage system planning, and understanding aquifer characteristics for sustainable water management.
Tips: Enter specific yield as a decimal value (typically between 0.01-0.35 for most soils), and total volume in cubic meters. Both values must be positive numbers.
Q1: What is specific yield and how is it determined?
A: Specific yield is the ratio of water that drains by gravity to the total volume of soil/rock. It's determined through laboratory tests on undisturbed samples or estimated from empirical relationships.
Q2: How does specific yield differ from porosity?
A: Porosity includes all void spaces, while specific yield only includes drainable water. Specific yield is always less than or equal to porosity.
Q3: What are typical specific yield values for different materials?
A: Clay: 0.01-0.05, Silt: 0.05-0.15, Sand: 0.15-0.30, Gravel: 0.20-0.35, depending on grain size distribution and compaction.
Q4: Why is this calculation important in engineering projects?
A: It helps in designing drainage systems, predicting groundwater lowering during construction, and assessing water availability for extraction.
Q5: Are there limitations to this simple formula?
A: The formula assumes complete drainage and doesn't account for time-dependent drainage, capillary effects, or heterogeneous material properties.