river landforms fluvial erosional erosion upsc stream lateral terraces stages cycle valley meander deposition ias rivers geography geomorphology life etc
glacial landforms depositional glacier outwash moraine plain eskers movement created erosional esker moraines drumlin glaciers erosion earth ias deposition arete
glacial landforms erosional glaciers topography depositional cirque arete glaciated moraine esker fjord pmfias drumlin