A plain bordering a river and subject to flooding

Flood Plain

DeltaA delta is a low, watery land formed at the mouth of a river.

Island

SwampA swamp is a low area of land that is always or sometimes saturated with water.

MarshAn area of soft, wet, low-lying land, characterized by grassy vegetation and often forming a transition zone between water and land.

HarborA place on the coast where vessels may find shelter, esp. one protected from rough water by piers, jetties, and other artificial structures.

Capea point or extension of land jutting out into water

Sea Levelthe level of the surface of the sea especially at its mean position midway between mean high and low water

BayA body of water partially enclosed by land but with a wide mouth, affording access to the sea:

PrairieAn extensive area of flat or rolling, predominantly treeless grassland, especially the large tract or plain of central North America

DesertA dry, often sandy region of little rainfall, extreme temperatures, and sparse vegetation

OasisA fertile or green spot in a desert or wasteland

MesaAn isolated flat-topped hill with steep sides

Mountaina natural elevation of the earth's surface rising

more or less abruptly to a summit

ValleyA low area of land between hills or mountains,

Glacier A huge mass of ice slowly flowing over a land mass

CanyonA deep gorge, typically one with a river flowing

through it, as found in North America

CliffA steep rock face, esp. at the edge of the sea

PlateauAn area of fairly level high ground.