These aerial photos were taken with color infrared film. The photos were taken in May of 1995.
This film captures the differences in the amount of heat radiated by the objects on the ground. Water radiates back very little of the sun's energy as heat and is almost black (or white if the sun happens to be reflecting off the surface). Pasture and meadowland, which at this time of year are putting out new vegetation, radiate back a lot of heat and therefore shows up as bright pink. Trees and shrubs which are putting out new vegetation show up as red, whereas those still without new leaves show up as dark gray. Fallow land, with dead grasses and other herbs, shows up as pinkish tan.
In the "young stream" image, the difference between the top and bottom portions are the result of pasting together two photographs taken at different times of the day.