Larkano District is divided into two parts by an embankment constructed to protect the eastern plains from hill torrents.  The western part consists of highlands (Khirthar Range mountains) and piedmont plains.  The Khirthar Range mountains attain a height of about 2200 meters at places and extend along the entire western boundary of the district.  The width of this mountain range is about 20 km.  Piedmont plains are dominated by alluvial fans deposited by Indus in the remote past.  These plains extend eastward from the edge of Khirthar range up to the old flood plains of Indus River.

The eastern part of the district consists of old flood plains stretching between the piedmont plains and the active flood plains along Indus River.  Indus has played a very important role in shaping the geomorphology of these areas over a long period of time.  Important topographic characteristics of old flood plains include basins, old channel beds, meander bars and levees.  These areas are protected from active flooding by an embankment constructed along the western bank of Indus.  The narrow strip of land between the protective embankment and the river is subject to active flooding.  Main characteristics in this area include level to gently undulating meander bars and levees, level plains, basins, and channel infills.