Relation of Forestry to the Control of Floods in the Mississippi Valley: Message from the President of the United States, Transmitting Communications from the Secretary of Agriculture Submitting Reports with Reference to the Relation of Forestry to the Control of Floods in the Mississippi Valley |
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Page 28
... average for the first two 7 - year periods , which included the virgin - timber epoch , is 1.775 inches a year greater than the average for the last two 7 - year periods . An absolute reduction in run - off of this amount applied to a ...
... average for the first two 7 - year periods , which included the virgin - timber epoch , is 1.775 inches a year greater than the average for the last two 7 - year periods . An absolute reduction in run - off of this amount applied to a ...
Page 35
... average of $ 5 per acre totals $ 29,500,000 or an average of $ 2,950.000 a year if spread over a period of 10 years . This does not include the additional areas from which lands are being currently approved for purchase by the National ...
... average of $ 5 per acre totals $ 29,500,000 or an average of $ 2,950.000 a year if spread over a period of 10 years . This does not include the additional areas from which lands are being currently approved for purchase by the National ...
Page 37
... average increase of 2 inches in the layer of humus , that means an increase in water - storage capacity of 1,815 cubic feet for each acre so transformed . On a total of 115,000 square miles the increase in water - storage capacity would ...
... average increase of 2 inches in the layer of humus , that means an increase in water - storage capacity of 1,815 cubic feet for each acre so transformed . On a total of 115,000 square miles the increase in water - storage capacity would ...
Page 38
... average rate of 23 tons per acre a year over a 6 - year period , as compared with an average annual loss of about 562 pounds on a seventh plot under sod . The farm lands in the Mississippi Valley which should be planted to forests are ...
... average rate of 23 tons per acre a year over a 6 - year period , as compared with an average annual loss of about 562 pounds on a seventh plot under sod . The farm lands in the Mississippi Valley which should be planted to forests are ...
Page 44
... average annual precipitation was 35.87 inches the average loss was 34.95 tons per acre annually . The average annual precipitation for the Bad Lands regions is about 15 inches . The average slope would undoubtedly be much greater than ...
... average annual precipitation was 35.87 inches the average loss was 34.95 tons per acre annually . The average annual precipitation for the Bad Lands regions is about 15 inches . The average slope would undoubtedly be much greater than ...
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Common terms and phrases
acres agricultural alluvial amount annual precipitation Appalachian Plateau Appalachian Valley Arkansas River average Bad Lands belt bluffs bottom lands cent chert clay County critical areas crops cultivated Cumberland Plateau drainage area drainage basin drained eastern eroded erosion especially extensive farm feet fire flood plain flow forest area forest cover forest land formations glacial grass grazing gullying hardwood hardwood type headwaters heavy Highland Rim hills hilly humus inches Kentucky limestone litter loess lumbering mean annual Mississippi River Missouri Missouri River Mountains national forests occur Ohio Ohio River Oklahoma Ouachita Ouachita Mountains Ozark pasture planting plateau portion prairie present protective value province rainfall region result ridges River Basin River drainage rolling run-off sand sandstone sandy shale silt loam slopes soil southern square miles steep streams surface Tennessee timber tion topography trees tributaries upland hardwood upper valley washing watershed western wood lots woodland
Popular passages
Page 15 - No public forest reservation shall be established, except to improve and protect the forest within the reservation, or for the purpose of securing favorable conditions of water flows, and to furnish a continuous supply of timber for the use and necessities of citizens of the United States...
Page 89 - Mexico, to be completed within twenty years; of the Mississippi River between the mouth of the Missouri and the mouth of the Ohio River...
Page 39 - States, or, in his discretion, with other suitable agencies, to assist the owners of farms in establishing, improving, and renewing wood lots, shelter belts, windbreaks and other valuable forest growth, and in growing and renewing useful timber crops...
Page 4 - Then God. our Lord, hindered the work with a mighty flood of the great river, which, at this time, began to come down with an enormous increase of water, which in the beginning overflowed the wide level ground between the river and the cliffs; then little by little it rose to the top of the cliffs.
Page 4 - The flood was 40 days In reaching its greatest height, which was the 20th of April, and it was a beautiful thing to look upon the sea where there had been fields, for! on each side of the river the water extended over 20 leagues of land, and all of this area was navigated by canoes, and nothing was seen but the tops of the tallest trees.
Page 51 - Forest rehabilitation is not urged as an alternative to engineering works for flood control. It is supplementary to the engineering program, but it is a supplement of such importance that no complete plan of flood control can omit it. ACKNOWLEDGMENT Space does not permit the inclusion of the names of the various individuals and agencies who have contributed to this report. Such a list would be a directory of people interested in the conservation of forests, streams, and water resources generally...
Page 63 - C.) humus per 2| acres was determined. Allowing 15 per cent for excess moisture content of air-dried over ovendried humus, the air-dried spruce and beech humus were found to have a retentive capacity of approximately 46.44 and 22.2 tons of water per acre, respectively. This amounts in volume to 1,510 cubic feet per acre for spruce and 712 cubic feet for beech humus, equivalent to a rainfall of 0.41 inch and 0.2 inch, respectively. The depth. of soil has a bearing upon the amount of water which it...
Page 8 - ... torrent of twenty miles an hour will carry boulders weighing one hundred tons. It is a self-evident fact that water falling on steep lands tends to rapid runoff. The laws just cited show that erosion is tremendously increased by rapidity of runoff. It follows that for any given type of soil the steepest lands are most subject to erosion. Therefore it is upon steep rough lands that forests as an erosion-preventive factor are most important. Coincident with retarding erosion and runoff, forests...
Page 404 - The rains run off, therefore, into the streams very quickly producing very sudden rises and floods. In dry weather as there is little or no ground water stored, the flow of the stream becomes very small and in some places dries up entirely. The banks of the river are low and in times of floods large areas are covered with water, delaying the planting of crops and at times destroying growing crops.