The word I cannot recall has a meaning of landform, but I am not sure whether landform can be used as a verb, probably not I suppose? And what's more, perhaps the word ends with -ise?
The only context I can recall is something like "the river is changing the terrain," but I don't remember what the word was, can someone help?
dictionary.com defines "landform" as:
noun Geology.
a specific geomorphic feature on the surface of the earth, ranging from large-scale features such as plains, plateaus, and mountains to minor features such as hills, valleys, and alluvial fans.
The Wikipedia aericle says:
A landform is a natural or artificial feature of the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography.
The National Geographic Society says:
A landform is a feature on the Earth's surface that is part of the terrain. Mountains, hills, plateaus, and plains are the four major types of landforms.
Several other dictionaries and reference works define the term "landform" similarly, as a noun. None that I found use or define it as a verb, meaning something like "to form the land".
One can speak of "building mountains" or "forming the terrain" or "shaping the landscape" or any of several other possible expressions.
The closest verb I can think of is
terraform
to alter the environment of (a celestial body) in order to make capable of supporting terrestrial life forms.
This might not be an exact match because your description doesn’t include anything about making it suitable for life.
