Should river depths get deeper as you travel down a river?

Question

My results suggest this untill it gets approx. halfgway down the river but then the depths are quite irregular. - need to know if first half results were correct and then the rest were anomalies?

thanks alot

Answer 1

There is not a sert rule about river depth along its course.  It is not true that the cross secion of te river remains the same, i.e., that if it is wider than it will be shallower.

Answer 2

It of course depends on the river!

A river with a source in the mountains may indeed deepn as it gets out of the mountains until it begins to flatten out at which point it spreads out and becomes shallower.  A river flowing into the ocean or a lake could be very deep with respect to the rest of the river if there has been a tectonic event, for example, which dropped the mouth of the river and allowed the stream to cut deeper as it approached it's discharge point.

Also, you need to clarify what you actually mean by "river depths" --- are you talking about the average depth of the river valley (i.e., from the top of the river bank to the deepest point in the river bed) or are you talking strictly about the "water depth" in the river?

Both are of course variable.

--added info ---

Think about it this way:

The volume of water in the river basically remains constant in cross section.  So if the water is deeper, the river bed is probably narrower and if the water is shallower, the river bed is probably wider.  This is just a basic observation assuming no change in flow other than the shape of the bed.

So if the water appears to be shallower toward the mouth, then look at the width --- is it wider?  Usually is at the mouth.