Outputs & Stores

  1. What is evaporation?
    Evaporation is the process where liquid changes into water vapor, typically from puddles and streams. The rate increases in hot, dry, windy conditions and with a larger soil surface area.

  2. What is transpiration?
    Transpiration is the process where water is drawn up from the soil by plants and leaves the plant as water vapor through tiny pores called stomata on the underside of the leaves.

  3. What is Potential Evapotranspiration (PET)?
    Potential Evapotranspiration (PET) refers to the amount of evaporation that would occur if an unlimited water source were available.

  4. What is river discharge?
    River discharge is the water that flows into the sea or moves within channels like streams or rivers. It can enter the channel through direct channel precipitation or other flows.

  5. What is the formula for river discharge?
    The formula for river discharge is Q = AV, where Q is discharge (m³/second), A is cross-sectional area, and V is velocity.

  6. What is interception in the drainage basin system?
    Interception is the process where precipitation is caught and stored by vegetation before it reaches the ground.

  7. What is surface water in the drainage basin system?
    Surface water occurs when the infiltration capacity is exceeded, causing water to build up on the surface.

  8. What are temporary stores of water?
    Temporary stores of water include puddles and turloughs, which hold water temporarily before it moves.

  9. What are permanent stores of water?
    Permanent stores include lakes and wetlands, which hold water on a more permanent basis.

  10. What is ground water?
    Groundwater is water that has percolated into bedrock and is a store of freshwater, accessible through wells and boreholes dug below the water table.

  11. What is ground water recharge?
    Groundwater recharge is the refilling of rock pores as water moves downward. It occurs when the rate of recharge is greater than the rate of abstraction.

  12. What is channel storage?
    Channel storage refers to all the water stored in rivers, streams, and drainage channels.

  13. What is soil moisture?
    Soil moisture is water held sub-surface in soil pores. Sandy soils have many large pores, making them permeable with quick infiltration rates, while clay soils are hygroscopic and less permeable.

  14. What is soil moisture deficit (SM Deficit)?
    SM Deficit occurs when available water is being used up, leading to drier conditions in the soil.

  15. What is soil moisture recharge (SM Recharge)?
    SM Recharge happens when precipitation exceeds potential evaporation, causing dry soil pores to refill with water.

  16. What is soil moisture surplus (SM Surplus)?
    SM Surplus occurs when the soil is saturated and cannot absorb more water, leading to surface runoff.

  17. What is soil moisture utilization (SM Utilisation)?
    SM Utilisation happens when evapotranspiration and other water uses exceed the precipitation rate, depleting soil moisture.

  18. What is field capacity?
    Field capacity is the amount of water the soil can hold once excess water has drained away, indicating the saturation point.

  19. What is the wilting point?
    The wilting point is the range of soil moisture content at which plants experience permanent wilting due to insufficient water.

  20. What is the water balance formula?
    The water balance formula is:
    Balance = Precipitation – (runoff + evapotranspiration + change in soil moisture).