Throughflow, Groundwater Flow and Surface Runoff also increase contributing to discharge. Term Channel Width. Term Channel Depth. Term Velocity. Definition Velocity increases since water accelerates downstream due to the forces of gravity. The river is also more efficient since proportionally less water is in contact with the bed and banks thus reducing energy lost to friction. Term Load Quantity. Term Load Particle Size. Term Channel Bed Roughness. Stream order 2 streams occur where two stream order 1 rivers come together at a confluence.
Stream order 3 streams occur where two stream order 2 rivers come together at a confluence not a stream order 2 with a 1, it must be the SAME stream order meeting. The stream order continues like this.
Cross sectional area is another useful measure, and it shows in metres squared the surface area of a river is you could take a slice through and stop the water!
This can be calculated in 2 ways, the average depth can be multiplied by the width to provide an approximate but not perfect measurement. If you have enough depth measurements, you could plot an accurate to scale cross section on graph paper and from that you will be able to calculate a more accurate cross sectional area.
The CSA should increase downstream as water feeds into main streams from tributary rivers. Wetted Perimeter is the measure of how much water contact there is with the bed and the banks of a river. This should also increase downstream as water feeds into main streams from tributary rivers. Hydraulic radius is a measure of how efficient the channel is at transporting water and sediment.
Hydraulic Radius is calculated by dividing the cross sectional area by the wetted perimeter. Channel bed roughness is a measure of how rough the bed of a river is. Gradient the slope of the land decreases as rivers flow because the river meanders across the land rather than erode into it and follow a straight path as it does in the source.
This means it covers a decrease in height over a longer distance the further downstream you get. This changes because the river changes from eroding vertically at the source, to laterally further downstream together with the effects of deposition further downstream too. LOAD - Stone size decreases downstream and the stones get rounder and smoother as rivers erode the rocks progressively as the stones are transported downstream. The processes of river erosion operate here.
The discharge will increase as the river approaches the sea. The size of the pebble will decrease down stream because the further downstream you go the quicker the river velocity. This means there will be more abrasion against the sides and bed of the river and the friction will be greater, this wears away the river load making it decrease in size. Begin typing your search term above and press enter to search.
Press ESC to cancel. Skip to content Home Useful tips How does the river load change downstream? Useful tips. Esther Fleming August 12, Table of Contents.
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