Action of running water - SS1 Geography Lesson Note

 Running water, typically in the form of a river, is water that flows downhill under the influence of gravity, gradually carving out channels and shaping landscapes. It is a dynamic and powerful force that transports water, sediment, and dissolved materials.

 

Sources of a River:

Rivers can have various sources, including:

• Springs: Natural groundwater emerges from the Earth's surface.
• Rainfall and Snowmelt: Precipitation accumulates and forms small streams, which eventually join to create a river.
• Glaciers: Melting glaciers contribute to the flow of water, forming glacier-fed rivers.

 

Courses of a River:

The course of a river describes its path from source to mouth. This course can be divided into different sections, including the headwaters, middle course, and lower course, each with specific characteristics.

Source:(geographisfun.com)

 

• Slope: The slope of a river, or its gradient, determines the speed of the water flow. Steeper slopes lead to faster-flowing water, while gentler slopes result in slower-moving water.

 

• Shape of Valley: Rivers shape valleys through erosion and deposition. V-shaped valleys are often formed by erosion, while broader U-shaped valleys may be the result of glacial activity.

 

• Volume of Water: The volume of water in a river varies with the season and geographical location. During periods of heavy rainfall or snowmelt, the volume increases, potentially causing flooding. In contrast, drier seasons lead to lower water levels.

 

• Size of Materials: Rivers transport various sizes of materials, including gravel, sand, silt, and clay. Larger, heavier materials are typically found near the source, while finer sediments are carried further downstream.

 

• Erosion and Deposition: Running water is a powerful agent of erosion, carving out valleys and shaping the landscape. It also deposits sediments when the flow velocity decreases, creating features like riverbanks, deltas, and alluvial plains.

 

• Meandering Rivers: Some rivers exhibit meandering patterns, where they snake back and forth in a sinuous path. Meanders are a result of the river's erosional and depositional processes.

 

• Human Impact: Human activities can significantly affect rivers through pollution, dam construction, and channelization, which can alter a river's course, water quality, and habitat.