Excess phosphates in runoff, excess fertilizers, and untreated human wastes return to water sources and cause in lakes.

a.
evaporation

b.
algae blooms

c.
nitrofication

d.
biomagnification

Are you asking about a street map usage  if so here is your answer  a street map for a very limited area could simply be a bit map or a .jpg image.  but a more general map would probably store the streets as vectors.  but you shouldn't assume that there is one way to do it

What have scientists learned about plant behavior by studying the dodder plant