The correct answer is D. All of the above.
The rate of infiltration is the rate at which water enters the soil. It is affected by a number of factors, including the soil type, the amount of rainfall, and the antecedent moisture content of the soil.
In the early part of a rainstorm, the rate of infiltration is high. This is because the soil is dry and the pores are open. As the rain continues to fall, the pores fill with water and the rate of infiltration decreases. This is because the water in the pores reduces the capillary forces that draw water into the soil.
In addition, as the soil becomes moistened, the clay particles swell and reduce the size of the pores. This further reduces the rate of infiltration.
Finally, raindrop impact can break up soil clumps and splash fine particles into the pores. This also reduces the rate of infiltration.
After several hours of rainfall, the rate of infiltration reaches a constant value. This is because the soil is saturated and the pores are filled with water. The rate of infiltration will remain constant until the soil begins to dry out.
Here are some additional details about each of the factors that affect the rate of infiltration:
- Soil type: The type of soil affects the rate of infiltration because different soils have different pore sizes. Soils with large pores have a higher rate of infiltration than soils with small pores.
- Amount of rainfall: The amount of rainfall affects the rate of infiltration because more rain means more water to infiltrate the soil. The rate of infiltration will increase as the amount of rainfall increases.
- Antecedent moisture content: The antecedent moisture content is the amount of water that is already in the soil before the rain starts to fall. The rate of infiltration will be lower if the soil is already wet than if the soil is dry.
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