Nature & You: Why are regions north of the river more sandy?
Why are regions north of a river more sandy?
Today's topic? Gravity. Specifically, the fact that all water runs downhill.
Case in point: The Mississippi River. Minnesota is at a higher elevation than is New Orleans. Don't act surprised when I share with you the situation whereby water from Minnesota gets across the continent and flows into the Gulf of Mexico through the river delta that is adjacent to New Orleans.
The surface waters in Oklahoma have the same goal in mind: To end up in the Gulf of Mexico. The lay of the land, however, prevents Oklahoma rivers from taking a direct, north-to-south route. Instead, Oklahoma's major courses pretty well (on average) head due east so that they might hook up with the "Mighty Miss-uh-sip!" and eventually commingle their waters with those in that huge river.
Here in central Oklahoma, the major rivers are the Canadian, North Canadian (Oklahoma River) and the Cimarron. Like I said, all of the rivers have a west-to-east orientation.
We're fast coming up on that season of the year where sand plum thickets snap out of their midwinter dormancy and come alive with masses of perfumey blossoms. If you should, by chance, like to schedule an outing to go partake of this sensory explosion, let me offer you some suggestions.
Search not the land that is south of the river. Go forth, instead, to the regions immediately north of the river. Keep watch for those high hummocks of terrain that literally shout: "Here there be sand!"
The plum thickets thrive in those places where they can sink their roots in a deep layer of sand.
It is not by accident that sand is predominant on the north side of our rivers. Over thousands and thousands of years, our part of the country has been characterized by dry, hot and drought-prone summers. Add to that the fact that our predominant winds are from south-to-north in the summer seasons. These annual winds have picked up sand off the dried-up riverbeds and then have dumped these airborne sands on the areas north of the river.
"Why," you might ask, "don't winter winds transport sand to the area on the south side of the river?" The answer is simple. The river sandbars are water-soaked in the winter season, and there is a scarcity of dry sand that is vulnerable to wind transport.
Thus ends your tutorial on Oklahoma topography and plant preferences for certain soil types.
— Neil Garrison, NewsOK Contributor
Neil Garrison was the longtime naturalist at a central Oklahoma nature center.