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A Total Forest Management Plan and Wildland Management Decision Support System
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The Flat Lands

Alternative Aspect Analyses

We shall next discuss slope and aspect but we need to designate the areas that are flat. Flat lands have neither slope nor aspect. Many other (including us) have combined these maps in the past and have probably created errors, misinterpretations, and increased the variance in some models unknowingly.

Map 1 shows the flat lands of the area. There are xxxxx acres, zzzzz % of the area estimated to be generally flat within each 30-meter mapcell or pixel called the Alpha Unit. Flat is defined as having a slope of less that 5% (a rise of less that 5 feet over a run of 100 feet).

Different agencies and individuals define flatland or flatness by different criteria. Here we suggest the need for a standard, but until this is accepted, the variety of definitions may assist in decision making about land and its characteristics.

These lands are typically in cove bottoms, ridge tops, and may be the most easily cultivated. They have fewest erosion problems and are most likely to contribute to ground water replacement. They are typically areas sought for placing structures and other human activity. They have the lowest energy requirements for animal movement (up or down movements have high-energy costs).

Vegetation shadows may be more important than topographic shadow (unless in the shade of mountains).

The pattern or distribution of these map cells may be surprising and may stimulate new questions about the predictability of land forms, the reasons for the pattern, and the means for describing it if in doing so animal or plant movement or observations of organisms might be better explained and eventually predicted.

It seems likely that certain plant species will be limited to such areas because of their soil leaching history, seed dispersal, and water budgets. (Comparing plants found in the cells with other findings might be an interesting exercise though not likely useful study.)

Slope Criterium (%)	Proportion of Ownership or Tract
0 equal or less than 1 equal or less than 2 equal or less than 3 equal or less than 4 equal or less than 5 equal or less than 6 equal or less than 7

It will be useful to develop further the concept of land flatness. The decision on the definition (or criterion) used can have profound effects on physical and biological phenomena. Its influence will be related to the scale of the analyses and the precision of the data. Standing water (lakes, ponds, etc.)needs to be included in these analyses. It is believed that water will not run off some land surfaces even though they have some slope. Some areas are quite rough but have an average slope of less that 5%. It will be useful to study maps and data results when progressively 1, 2,...7 % are used as the upper criterion for "flat." There is not likely to be a continuous ditribution of area designated as flat when this continuous distribution of slopes classes is used. We need to isolate the phenomena, justify the criterion selected and consistently map flat lands as separate from sloping lands or land with slope. Flat is not a slope category. It is likely that flat lands have been forced into lands with small slopes and aspects and such forcing may have resulted in higher than necessary variance in ecological observations and forest site quality analyses.

One index of area flatness is the elevation ratio of maximum elevation / minimum elevation where 1.0 is flat.

Reshaping the Surface

After mining and other major land movement work we recommend immediately thereafter beginning the reshaping and regrading process. This prevents unnecessary erosion of the site. In the backfilling operation, all black soil and toxic materials will be buried at least four feed deep. Limestone will be mixed with toxic materials to help neutralize them. All large rocks will also be buried.

Grading will be done to return the area to contours matching the desired use of the land. Agricultural crops, industrial sites, residential sites, and some types of recreation will be graded to be very level. Steeper areas will be acceptable for pastures, woodland, wildlife, and some recreation. During grading, the movement of the soil will be help to a minimum to prevent compaction. Final grading will be done only when the soil is dry for this same reason. Bench areas will be sloped slightly toward the highwall to prevent rainfall runoff on the outslopes. After the grading is complete, no spoil piles or depressions will remain. The soil will then be compacted just enough for stabilization.

References

Anderson, D. R. 1981.A climatological information system for natural resource management: temperature. M.S. Thesis, VPIandSU, Blacksburg, Virginia. viii + 220 pp.

Fies, M. L. Predicting forest cover types in Southwestern Virginia using topographic information. M.S. Thesis, VPIandSU, Blacksburg, Virginia. xii + 234 p.

Grender, G. C. 1976. Topo II 1: A FORTRAN program for terrain analysis. Computers and Geosciences 2: 195-209.

Halverson, H. G. and J. L. Smith. 1979. Solar radiation as a forest management tool: a primer of principles and application. Gen. Tech. Report PSW-33, Pacific Southwest Forest and Range Exp. Station, Berkeley, CA. 13 pp.

Hamill, J. F. 1976.A computer-based methodology for estimating potential wildlife productivity for large areas. M.S. Thesis, VPIandSU, Blacksburg, Virginia.x + 94 pp.

Hoar, A. R. 1980. A method for mapping the probable ranges of endangered mammals in Virginia. Unpub. M.S. Thesis, VPIandSU, B1acksburg,Virginia.

Lawrence, G. E. 1976. A computer-based insolation mapping algorithm for large areas. Unpublished M.S. Thesis, VPIandSU, Blacksburg, Virginia. viii + 129 pp.

Stage, A. R. 1963. A mathematical approach to polymorphic site index curves for grand fir.For. Sci. 9: 167-180.

Stage, A. R.1969. Computing procedure for grand fir site evaluation and productivity estimation.USDA For. Service Res. lab INT-98, Ogden, Utah.6 p.

Stage, A. R.1976. An expression for the effect of aspect slope, and habitat type on tree growth. For. Sci. 22:457-460.

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This Web site is maintained by R. H. Giles, Jr.
Last revision July 2, 2004.