IMG_2875The Mississippi River builds a great delta where it enters the Gulf of Mexico, while the mighty Columbia Rver barely creates a sand bar where it runs into the Pacific Ocean. The desert scene in this photo speaks more to the Columbia than the Mississippi, as similar environmental forces are at work in both places. The Mississippi Delta owes its existence to gentle currents in the Gulf which allow sediment to drop slowly from suspension as it exits the river mouth. This causes the delta to grow and extend over centuries. The Columbia River on the other hand must immediately hand over it’s load of silt, sand and other particulates to powerful longshore currents and storm surge which perpetually assault the river mouth to sweep away sediment and destroy any chance for a river bar or delta forming. The small desert tributary stream in this photo is like the Columbia in that it feeds (when flowing) into a more powerful flow which carries away absolutely everything, leaving a smooth and sharp division point where the small stream meets the larger river. The result is that whatever sediment the little stream brings to the party is swiftly and utterly borne away by the greater power of the larger flood. This is actually rather rare to see, as most tributary streams are able to establish at least a small foothold in the larger river where they intersect. If you’ve ever rafted down the Colorado River and came upon rapids over a shallow bar and then looked around, it’s likely you’d see a smaller tributary stream entering the big river at the edge of the bar. That little stream is having it’s way with the mighty Colorado, which is strong but relatively mild in comparison with the proportional energies conveyed via our small and large flash flood channels. So while even famous and powerful rivers can be tamed by their tributaries it’s interesting to see this little nameless channel doing it’s best to ensure one of its tributaries isn’t able to get a word…er, sandbar, in edgewise.

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