Environmental Geomorphology and Landscape Conservation

Binghamton Geomorphology Symposium 1

Donald R. Coates

• Publisher: Routledge
• Year: 2020
• eBook ISBN: 9781000046595
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

This book, first published in 1973, focuses on non-urban terrain, and presents a uniquely balanced historical treatment of both the land degradation induced by man and his efforts at conservation, preservation and reclamation.

Editor’s Comments on Papers 1, 2, and 3

1Strahler: The Nature of Induced Erosion and Aggradation

2Glenn: Denudation and Erosion in the Southern Appalachian Region and the Monongahela Basin

3Bennett and Chapline: Soil Erosion a National Menace. Part I: Some Aspects of the Wastage Caused by Soil Erosion

Soil Erosion and Siltation

As pointed out on page 129 of Volume I of this trio of volumes, erosion of the land always produces the twin problem of siltation (or “sedimentation” or “aggradation”). This double jeopardy of landscape debasement constitutes the greatest environmental problem of all. In this section the Strahler, Glenn, and Bennett articles emphasize erosional aspects of terrain, and the Eakin and Stall articles stress the deposition of materials after their removal from hillslopes.

A Governor’s Conference called by President Theodore Roosevelt in the early 1900s produced some of the earliest literature about soil erosion and was a beginning for the twentieth-century conservation movement (see Part II).

When our soils are gone, we too must go, unless we shall find some way to feed on raw rock or its equivalent. The immense tonnage of soil-material carried out to sea annually by our rivers, even when allowance is made for laudable wash, and for material derived from the river channels, is an impressive warning of the danger of negligent practices. Nor is this all; the wash from one acre is often made the waste-cover for another acre, or for several. Sometimes one’s loss is another’s gain, but all too frequently one’s loss is another’s disaster; and the 1,000,000,000 or more tons of richest soil-matter annually carried into the sea by our rivers is the Nation’s loss (Chamberlin, 1908, p. 78).

Thousands of acres in the East and South have been made unfit for tillage. North Carolina was, a century ago, one of the greatest agricultural states of the country and one of the wealthiest. Today as you ride through the South you see everywhere land gullied by torrential rains; red and yellow clay banks exposed where once were fertile fields; and agriculture reduced because its main support has been washed away. Millions of acres, in places to the extent of one-tenth of the entire arable area, have been so injured that no industry and no care can restore them (Hill, 1908, p. 67).

Numerous articles have been written in the United States and other countries decrying the great abuse of the lands by man. The following statements typify such remarks in the United States:

Modern man still assumes that because for thousands of years nature seemed to have the ability to absorb an increasing number and variety of environmental insults it will continue to be able to do so. Man still does not clearly understand that he lives in a delicate equilibrium with the biosphere—upon the precious earth crust, using and re-using the waters, drawing breath from the shallow sea of air. Because he has not understood this, he is now faced with an urgent necessity for defining a hospitable environment (Linton, 1970, p. 337).

Erosion, like many another curse of humanity, grows by what it feeds upon. It behaves like compound interest. Beginning first on the exposed surface of normal soil, it first removes the sponge-like, water-holding layer of dark humus, which normally is held in place by the roots of plants and protected by their tops (Sears, 1947, p. 98).

Today the land of our forefathers is an unhappy land—scalped, mauled, defiled, and poisoned (Rienow and Rienow, 1967, p. 283).

Similar concern was world-wide, as indicated by the following:

That soil erosion is extending rapidly over many parts of the Union … that besides slooting, there is a great deal of surface erosion, both by water and wind … that the soil of the Union, our most valuable asset, irreplaceable and part of this soil and valuable plant food is lost for ever … that great damage is done by the eroded material silting up reservoirs and that soil erosion caused greater irregularity in the flow of our rivers, thereby increasing the cost of irrigation works and the cost of producing feeding stuffs … that soil erosion is caused, mainly by deterioration of the vegetal cover brought about by incorrect veld management (Union of South Africa, 1923, p. 15).

Jacks and Whyte (1939) present an international appraisal of erosion in their pace-setting book:

… in South Africa, according to General J. C. Smuts, erosion is the biggest problem confronting the country, bigger than any politics (p. 5).

The results of land (in Africa) misuse are only now becoming apparent in a grave form, as much of the land in the settled areas has been cultivated for only fifteen to twenty-five years.

Some areas in Kenya have already reached such a state of devastation that nothing short of the expenditure of enormous and quite impossible sums of money could restore the land for human use … (p. 63).

The most urgent problem in New Zealand, however, is the control of floods and the prevention of the excessive washing of soil down the short river courses into the sea, a process which threatens to leave the country like an “emaciated skeleton.” Deforestation by cutting, burning, or overgrazing of the undergrowth in the mountain areas by sheep, cattle, deer and other animals has greatly accelerated run-off and soil wash, and there is hardly a river in the country which is not affected by periodic flooding (p. 74).

… erosion is the modern symptom of maladjustment between human society and its environment. It is a warning that Nature is in full revolt against the sudden incursion of an exotic civilization into her ordered domains (p. 11).

And more recently such scientists as Bouillenne (1962) have called attention to the continued progression of accelerated erosional problems caused by man:

In the great forest massif of Central Africa, where the rate of regression is rapid, the present state of affairs is becoming disastrous, owing to the activity of the natives, who still start fires to clear the land for hunting and cultivation. This forest area, which is bounded on the north by the Sahara and on the south by the Kalahari, is receding with alarming speed. On all sides the deserts are advancing. It is estimated that in French Equatorial Africa alone the loss of fertilizing matter during the present generation has amounted to half a billion tons, and in a single cotton district in the Congo agronomists have shown that in 6 years 30,000 square kilometers of soil have been ruined (p. 704).

Earlier Sears (1947) referred to such man-induced changes as “deserts on the march.”

In much of the literature any erosion of the land has generally been viewed as undesirable. Some pedologists, however, have urged the importance of separating the normal erosion, which may be necessary for the continued regeneration of soils, from the extraordinarily high erosion rates caused by man. For example, Smith and Stamey (1965) attempted to establish “the range of tolerable erosion.” Although there are many variables that must be considered, they fix the amount between 0.5 and 6 ton acre annually. In the National Academy of Science’s Symposium on Dynamics of Land-Erosion, Sharpe (1941) indicates some of the differences:

Normal soil-development, normal erosion, normal balance of the several processes of denudation, and even normal sculpturing of the surface of humid lands, then, can take place only with the presence of a normal vegetal cover. Man, by removing the natural vegetation, has destroyed the balance of all of these relations. In clearing the forests and baring the land for cultivation, man has added his destructive powers to those of nature. Runoff has been greatly increased, both in rate and amount and as a result, streams now flow less regularly, their load is carried fitfully, and their floods reach higher crests. Changes wrought by man have increased sheet-erosion, rilling, gullying, and wind-erosion. These processes have accelerated (p. 236–237).

A problem arises concerning the determination of whether man has caused the environmental deterioration or whether it is due to natural processes, because even in nature there are great differences in hillslope erosion rates and sediment yields. In two undisturbed areas of Malaysia, Douglas (1967) found:

… whereas a catchment with 94% of its area under natural vegetation had a sediment yield of 21.1 m³/km²/yr, a neighbouring catchment with only 64% of the area covered by natural forest had a yield of 103.1 m³/km²/yr (p. 20).

As Leopold, Wolman, and Miller (1964) point out:

… as a rule the geomorphic effects produced by man are the same as those produced without him. Usually man simply changes the magnitude of certain variables in the system. These in turn produce responses, perhaps only acceleration or deceleration, in the fundamental geomorphic processes. The appropriate principles are not abrogated (p. 434).

There is general agreement on the size of the increment in erosion caused by man. Brown (1970) has estimated world-wide natural erosion rates from 12 to 1500 m³/km²/yr and man-induced erosion rates from 1500 to 85,000 m³/km²/yr. The range is explained in regional variations, both physical and human.

An interesting paradox can occur when man attempts to inhibit his own style of erosion. In studying the gullying problem in South Carolina, Ireland, Sharpe, and Eargle (1939) found that it “… usually has been brought about by roads and trenches, and by terraces that have been improperly constructed or maintained . …” Thus man has actually caused additional erosion by the very means with which he has attempted to control and prevent it.

The usual an...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Acknowledgments and Permissions
• Series Editor’s Preface
• Contents by Author
• Introduction
• I. Man-Induced Terrain Degradation
• Editor’s Comments on Papers 1, 2, and 3
• 1. Strahler, A. N.: "The Nature of Induced Erosion and Aggradation"
• 2. Glenn, L. C.: “Denudation and Erosion in the Southern Appalachian Region and the Monongahela Basin”
• 3. Bennett, Η. H., and W. R. Chapline: “Soil Erosion a National Menace. Part 1: Some Aspects of the Wastage Caused by Soil Erosion”
• Editor’s Comments on Papers 4 and 5
• 4. Eakin, Η. M.: “Silting of Reservoirs”
• 5. Stall, J. B.: “Man’s Role in Affecting the Sedimentation of Streams and Reservoirs”
• Editor’s Comments on Papers 6 Through 9
• 6. Aghassy, J.: “Man-Induced Badlands Topography”
• 7. Parizek, R. R.: “Impact of Highways on the Hydrogeologic Environment”
• 8. Black, R. F.: “Permafrost”
• 9. Daniels, R. B.: “Entrenchment of the Willow Drainage Ditch, Harrison County, Iowa”
• Editor’s Comments on Papers 10 Through 14
• 10. Askochensky, A. N.: “Basic Trends and Methods of Water Control in the Arid Zones of the Soviet Union”
• 11. England, Η. N.: “Problems of Irrigated Areas”
• 12. Poland, J. F., and G. H. Davis: “Subsidence of the Land Surface in the Tulare-Wasco (Delano) and Los Banos-Kettleman City Area, San Joaquin Valley, California”
• 13. Hamilton, D. H., and R. L. Meehan: “Ground Rupture in the Baldwin Hills”
• 14. Curry, R. R.: “Soil Destruction Associated with Forest Management and Prospects for Recovery in Geologic Time”
• II. Soil Conservation
• Editor’s Comments on Papers 15 Through 20
• 15. Jepson, H. G.: “Prevention and Control of Gullies”
• 16. Ramser, C. E.: “Prevention of the Erosion of Farmlands by Terracing”
• 17. Lowdermilk, W. C.: “Erosion Control in Japan”
• 18. Eliassen, S.: “Soil Erosion and River Regulation with Special Reference to the Yellow River”
• 19. Brown, C. B.: “Protecting Bottomlands from Erosional Debris: A Case Study”
• 20. Whitfield, C. J.: “Sand-Dune Reclamation in the Southern Great Plains”
• III. Landscape Management
• Editor’s Comments on Papers 21 Through 24
• 21. Bailey, R. G.: “Forest Land Use Implications”
• 22. U.S.D.A.: “Restoring Surface-Mined Land”
• 23. Beatty, R. Α.: “The Inert Becomes ‘Ert’”
• 24. Zube, E.: “A New Technology for Taconite Badlands”
• Editor’s Comments on Papers 25 and 26
• 25. Craighead, F. C., and J. J. Craighead: “River Systems: Recreational Classification, Inventory and Evaluation”
• 26. Leopold, L. B.: “Landscape Esthetics”
• References
• Author Citation Index
• Subject Index