Region
Abū Ẓaby (Emirate)
1
Adak Island
1
Adams County
1
Africa
4
Africa, East
1
Africa, North
1
Africa, Sub-Saharan
3
Agency Lake
1
Alabama
7
Alaska
29
Alaska, Gulf of
2
Alaska, Southeast
1
Albania
1
Albany
1
Albuquerque
4
Albuquerque Basin
2
Albuquerque Basin (N.M.)
1
Albuquerque Region
4
Albuquerque-Belen Basin
1
Albuquerque-Belen Basin (N.M.)
1
Aleutian Basin
1
Aleutian Islands
1
Allegheny County
1
Allen County
1
Alpine County
4
Altus, Lake, Watershed (Okla. and Tex.)
1
America
3
American Samoa
1
Anacostia River Watershed (Md. and Washington, D.C.)
1
Anchorage
2
Anchorage Region
1
Angola
1
Annaquatucket River
2
Antelope Valley
2
Antwerp
1
Antwerp (Belgium)
1
Apalachicola River Watershed
2
Apopka, Lake, Watershed
1
Appalachian Mountains
1
Appalachian Region
2
Arab countries
1
Arctic Ocean
2
Arikaree Aquifer
2
Arizona
18
Arkansas
24
Arkansas River
1
Arkansas River Watershed
2
Asia
8
Assabet River Watershed
1
Atchafalaya River Watershed (La.)
1
more ...