Sunday, May 31, 2009

Landscapes North: Northrige/Vandaila/Butler Topography

One of the peculiar features of the Dayton area is the landscape, which isn't quite the midwestern stereotype of flat lands and cornfields.

An example is the reigon directly north of the city, between the Great Miami and Stillwater rivers. Using a topographic map from around 1903 (before the start of suburbanization) as a basis one can do some topographical analyses.

Identifying various types:

1. Midwestern Plains: the stereotypical midwest landscape, a mix of farms and woolots.

2. Flat to Rolling Country: still charactersitic of the plains, but more rolling, not as flat

3. Hills & Valleys/Creek Valley: valleys along watercourses, steeper slopes.

4. Bluffs & Steep Slopes: well defined valley walls with steep slopes and ravines.

5. Flats & Bottoms: nearly dead-level land along the rivers.

6. Bench: Flat land just above the river bottoms, seperated from them by a low bluff or hill

7. River Oxbows/Changing River Course: The Great Miami apparently meandered in its bottoms, changing course from time to time, leaving oxbows. This process has stopped due to flood control.

8. The Ridge: A somewhat unique feature, perhaps a glacial remnant, a higher piece of land with steep slopes on either side.
Also shown are "the narrows", which is really not a river narrows but a tight spot on Frederick Pike, where the road is wedged between some steep slopes and river.

One can see how the fairly flat landscape of the midwestern plains breaks into tongues of more rolling yet still mostly level terrain, but then drops to the river and creek valleys via hills and steeper slopes, and how extensive the flatlands are along rivers.

Laying the rectantular coordinate survey system over the landscape yields the "Midwestern Grid"....
..which drives the location of property lines and later roads. Eventually there was the canal (shown as a lighter blue) and railroad (in black) and country villages.

..finally, the cultural landscape on the eve of suburbanization:

A closer look at two parts of the landscape. the Northridge area, with Dixie Drive drawn in in red.

..and the Vandalia/Chambersburg area, which is at a higher evelvation. The drainage divide between the Stillwater and Great Miami is shown. North Dixie Drive and US 40/National Road are drawn in for reference.

Taking two diagrammatic cross sections one can see, in the first, how the land steps down to the Great Miami. The low bluff that seperates the bench from the bottom lands is evident inside the city of Dayton, too, in South Park (at the Emerson School), St Annes Hill (Dutoit Street and Steamboat House hills) and Front Street (the hill on 2nd as it passes between the buildings). In West Dayton its visible as the rise just the the east of Paul Lawrence Dunbar Street.
The cross section along the Great Miami Valley shows how the land rises from south (left) to north (right), which might account for the relatively high bluffs and valley walls in the vicinity of Vandalia and I-70, vicinity the Taylorsville Dam. The rise in evlevation is 262 feet, from 748 feet near where north Dixie crosses the river to 1,010 feet near the airport. The river is at around 770 feet at Taylorsville dam.

And how, when one is in the bottomlands near the Great Miami @ Dixie, one does not get a sense of being in a valley due to the indistinct bluffs and valley walls.

So perhaps a more subtle and varied landscape than one would expect.

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