Water movement or rain movement or more accurately; forest hydrology processes for moist tropical rain forests goes something like this. There are three ways to which the rain water could get to the forest floor. The first one, a small portion of it at least, is by direct fall through, meaning that the rain droplets do not land on any of the leaves of this thick canopy or the stems of the densely populated of the forest’s strata, hence the small portion of it. The second, with an even smaller portion, is when the rain droplets land on the stems of the inhabitants; in this case, would be the arboreal occupants of the forest. The third carries the most prominent portion of the volume of rainwater reaching the forest floor, and that is by the water droplets to land on the leaves. The term “crown drip” sometimes assimilate itself to this process. That is why we can see a trending pattern in the leaves of these tropical arboreals, we see leaves having pointy apex; apex is the ‘longitudinal’ end of the leaf that is not attached to the petiole. Classically, this feature is generalized for trees in the tropical region, to counter the heavy bombardment of torrential storms in an effort to keep the surface of the leaves dry. This synergizes effortlessly with diversity within the strata, the rate of senescing in the region and the insanely fast rate of decomposition on the forest floor.
With all this being said, these portions represents only 80% of the precipitation that the forests are receiving. The other 20% is stuck or is stagnant all over the canopy, waiting for enough sunlight and heat to be able to evaporate back into the atmosphere. This is one way that water is lost in a moist tropical forest; another is via drainage into the nearest stream.
Now that we have these pathways for water to reach the forest floor, we need to take into consideration what is on the forest floor; what makes the forest floor. The forest floor is made out of leaf litter; and lots of it. The concept here is that the leaf litter cushion the impact brought upon by the droplets of rainwater hitting the soil from the last drip tip of a leaf. “Raindrop splash” is the term for this. So now the water has to go through leaf litter and topsoil before permeating the soil.
In an undisturbed forest, this is the scenario.
Whereas for the logged-over forest, here you have rain water pouring like mad, beating the ground to submission, creating siltation; the ground could be depicted as having a bad case of the flu, with a severe case of a runny nose.
Here you have the colour of milk tea on the ground, running, bringing within it, a trace amount of sand, silt, and clay. A trickle becomes a stream is not even incentive to vividly describe the condition of most of our rivers and streams.