(5) A marsh is a treeless wetland.. Public Domain.
(6) http://en.wikipedia.org/wiki/File:Canadian_Falls_Aug_2004.JPG. Public
Domain.
(7) NASA.http://en.wikipedia.org/wiki/File:
Hurricane_Katrina_August_28_2005_NASA.jpg. Public Domain.
(8) NASA. http://en.wikipedia.org/wiki/File:NileDelta-EO.JPG. (a) GNU-FDL
(b) Public Domain.
(9) Geoff Ruth.. CC-BY-SA.
(10) http://en.wikipedia.org/wiki/Image:CypressSwamp.jpg. GNU-FDL.
(11) NASA.
http://commons.wikimedia.org/wiki/File:Susquehanna_ETM_19990923_lrg.jpg.
Public Domain.
(12) Geoff Ruth.. CC-BY-SA.
(13) Ansgar Walk.
http://commons.wikimedia.org/wiki/File:Iceberg_12_2000_08_13.jpg.
CC-BY-SA 2.5.
(14) http://commons.wikimedia.org/wiki/File:Boscastle_RAF_SeaKing.jpg.
GNU-FDL.
(15) http://en.wikipedia.org/wiki/File:Above_the_Clouds.jpg. CC-BY 3.0.
(16) NASA.
http://commons.wikimedia.org/wiki/File:Earth_Western_Hemisphere.jpg.
Public Domain.
(17) http://en.wikipedia.org/wiki/Old_Faithful_Geyser. Public Domain.
(18) http://en.wikipedia.org/wiki/File:Traditional_Well-Kerala.JPG. GNU-FDL.
(19) http://en.wikipedia.org/wiki/File:Nacentemackinac.jpg. (a) GNU-FDL
(b)GNU-FDL.
(20) Ponds are small, enclosed bodies of water.. CC-BY 2.0.
(21) http://en.wikipedia.org/wiki/File:TravellingSprinkler.JPG. GNU-FDL.
(22) USGS.http://en.wikipedia.org/wiki/Water_cycle. GNU-FDL.
(23) The divides of North America.. GNU-FDL.