Question

what is high porosity and low permeability

Answer 1

High porosity is when the percentage of pore space(ie air/water) is relatively high. A highly porous soil is going to allow for the flow of water much more easily (think of trying to traverse through a thin crowd vs a jam packed Hong Kong type crowd) as well as a higher capacity for holding water (although not for keeping it). Low permeability is when it is difficult for something (water usually) to flow through a medium (soil usually). So if you have a soil with low permeability, if you pour enough water into it, the water will begin to pool quite quickly.

Answer 2

Which is one way that chemical weathering influences mechanical weathering?


A.
Winds scrape the rock layers away, exposing them to acids in the rain.


B.
The roots of plants fit into cracks of iron-rich rocks, exposing them to moisture in the air, which causes the rocks to rust.


C.
Acids in the rain create holes in the rock, which allows water to get inside for ice wedging.


D.
Plants secrete acids that create holes in iron-rich rocks, thereby exposing them to moisture in the air, which causes the rocks to rust.