I noticed these detailed tree-like river structures in Google Earth

enter image description here

Google Maps link

How and why do these form? Rivers don't typically split. What would cause the water to keep branching off again and again, forming these tree-like fractal patterns? I count as many as 7-8 branch splits even in the smaller trees.

I expect the answers will provide qualitative explanations, but if anyone can connect it to quantitative physical models that would be even better (e.g. diffusion limited aggregation, viscous fingering, dielectric breakdown all have analogous mechanisms behind them; could this one be related?)


2 Answers 2


The river isn't splitting. The picture shows a number of dendritic drainage channels flowing into a larger river/stream. They are the most common form of topographical draining system. They develop in gently sloping topography and they ...

develops in regions underlain by homogeneous material. That is, the subsurface geology has a similar resistance to weathering so there is no apparent control over the direction the tributaries take. Tributaries joining larger streams at acute angle (less than 90 degrees) [Earth Drainage Systems].

You'll notice in the picture all the drainage channels intersect the river at approximately 90 degrees. Also it appears the channels dendritic channels have formed in what looks like a sandy/silty sediment, again homogenous material.

Other sources that may be helpful:

Experiment to Examine Dendritic River Systems

Dendritic river flow simulations

Flow direction & branching geometry

Dendritic Design

  • 1
    $\begingroup$ A lot of interesting information here, it'll take a while before I can go through them and get back. $\endgroup$
    – Glacialis
    Commented Feb 6, 2015 at 16:23
  • $\begingroup$ Unfortunately, you got the direction of flow wrong. $\endgroup$
    – Spencer
    Commented Sep 16, 2018 at 18:03

It does look like a typical dendritic flow pattern of surface water flowing into a stream. What is unusual for this pattern is that these channels seem to be entering the river at 90 degrees. However, if the water is flowing out of the river through breaches in the bank or berm, then these branches would be carrying water and sediment out of the river and into a low lying area forming miniature deltas. If you Google "delta flow pattern" you will see some pictures of this same pattern.


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