Two important measures of a population are population size, the number of individuals, and population density, the number of individuals per unit area or volume. Ecologists estimate the size and density of populations using quadrats and the mark-recapture method.
Glacial ice can transport rocks as big as a house. It has very high transport competence and moves very slowly across a very large distance.
The maximum size of particles that a stream can transport is defined as stream competence. This is a concept under hydrology. Streams depending on its velocity can carry sand, mud, silt and cobble along with the dissolved and suspended load.
The process by which Ocean waves transport sediments, large pebbles and boulders is referred to as Coastal Transportation. During Coastal transportation, large pebbles and boulders are rolled along the seabottom, while beach material is bounced along the seabed.
