of the most interesting aspects of these processes is that they
interact to reinforce one another. Atmosphere disturbances caused
by urban activities increase precipitation, which increases erosion,
which carries more sediment into river channels. Disturbances of
land can cause disturbances of aquatic environments and increased
levels of dust in the atmosphere. These cyclic and cumulative effects
mean that urban ecological relations can become particularly complex.
One change leads to another and another in a complicated, spiraling
series of feedback loops.