Why does river discharge increase downstream?

Why does river discharge increase downstream?

Changes Downstream As one moves along a stream in the downstream direction: Discharge increases, as noted above, because water is added to the stream from tributary streams and groundwater. As discharge increases, the width, depth, and average velocity of the stream increase.

Why are river profiles concave?

River profiles usually deviate from smooth curves due to lateral water and sediment input from hillslopes and tributaries and spatial changes in channel width or bed friction [Snow and Slingerland, 1987].

What is longitudinal profile of a river?

Longitudinal profile Rivers are linear systems which show a gradient of characters along their length. Ideally the longitudinal profile of a river is concave with a steep upper portion near the source, giving way to reaches of progressively less gradient as the mouth is approached.

How concave are river channels?

Declining gradients along the length of the channel lead to river longitudinal profiles that tend to be concave up. Over a century ago, Shaler (1899) postulated that as channels gain drainage area their slopes would decline, hindering their ability to erode.

What type of erosion makes a river deeper?

Vertical erosion

What landforms are found in the lower course of a river?

Deltas

• Arcuate or fan-shaped – the land around the river mouth arches out into the sea and the river splits many times on the way to the sea, creating a fan effect. The Niger Delta.
• Cuspate – the land around the mouth of the river juts out arrow-like into the sea. The Ebro Delta.
• The Mississippi Delta.

What is the upper course of the river?

The upper course of a river is where the river begins its path toward the sea. This part of the river arguably has the most landscape features, and biggest range of physical features. Features of a river’s upper course: Source – This is where the river begins.

What is the first stage of a river called?

Source

Which course of a river is likely to flood the most?

The faster the water reaches the river, the more likely it will flood. Relief – a steep valley is more likely to flood than a flatter valley because the rainfall will run off into the river more quickly. Geology – permeable rocks allow water to pass through pores and cracks, whereas impermeable rocks do not.

How do humans cause rivers to flood?

Human causes of flooding Constructing buildings and surrounding roads and paths creates impermeable surfaces which increase surface run-off. Drains also increase the flow of water into surrounding rivers, increasing the flood risk.

What increases flood risk?

Flooding occurs naturally but human activity has significantly altered natural drainage processes, often causing greater flood risk. Urbanisation has reduced the ability of land to absorb rainfall through the introduction of hard, impermeable surfaces.

What are human activities that cause flooding?

Human activities that degrade the environment often increases flooding. These activities include: Deforestation. The lack of vegetation encourages water to flow over the surface rather than infiltrate into the soil thus increasing surface runoff.

What is the main cause of floods?

Severe flooding is caused by atmospheric conditions that lead to heavy rain or the rapid melting of snow and ice. Geography can also make an area more likely to flood. For example, areas near rivers and cities are often at risk for flash floods. A flood is an overflow of water onto land that is normally dry.

What are 3 causes of flooding?

Physical causes of flooding:

• heavy rainfall.
• long periods of rain.
• snowmelt.
• steep slopes.
• impermeable rock (doesn’t allow water through)
• very wet, saturated soils.
• compacted or dry soil.

What are the main causes of drought and flood?

Droughts occur when an abnormally long dry period uses up available water resources. Floods happen when watercourses or rain swallow up land that is usually uncovered. These natural disasters are often made worse by human action. Paved roads and cities full of asphalt prevent water from sinking into the ground.

How can we prevent flood?

Consider these suggestions to prevent or minimize flood damage in your home or business

1. Install water sensors or flood detection systems.
2. Regularly test your sump pump & consider a battery back up.
3. Regularly clear debris from drains and ditches.
4. Regularly check and clean downspouts and gutters.