The earthen embankments constructed parallel to the river banks at some suitable distance for flood control, are known as:

Explanation:

The earth embankments constructed parallel to the river banks at some suitable distance for flood control are known as both dykes and levees.

Levees:

• Levees construction is a method of river training.
• They are constructed to protect the riverbanks from flooding.
• It is basically an embankment constructed along the river so that water remains contained in between the levees during flooding.
• Levees protect land that is normally dry but that may be flooded when rain or melting snow raises the water level in a body of water, such as a river.

Dykes:

• A dike is a barrier used to regulate or hold back water from a river, lake, or even the ocean. Or in other words, A dyke is a thick wall that is built to stop water from flooding onto low-lying land or area from a river or from the sea.
• Dikes protect land that would naturally be underwater most of the time.
• Levees and dikes look alike, and sometimes the terms levee and dike are used interchangeably.

River wall:

• A river wall means a structure that forms the boundary between the river and the land. It is made to confine a river within definite bounds, either to prevent denudation or erosion of the banks or overflow of the adjacent land or to concentrate the force of the stream within a smaller area for the purpose of deepening a navigable channel.