Transcript Chapter 17 Soil Erosion and Its Control Water lays waste to unprotected soil.

Chapter 17 Soil Erosion and Its Control
Water lays waste to unprotected soil. (R. Weil)
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Land Degradation
• Desertification – The spreading of desert
conditions that disrupt semiarid and arid
ecosystems.
– Causes: overgrazing, removal of vegetation,
and inappropriate agricultural practices
• Soil Degradation – The deterioration of soil
conditions
– Causes: compaction, acidification, and salt
accumulation
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.1
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.2
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.6
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.7
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.9
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.10
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.10
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.10
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Rainfall Erosivity Factor R
Figure 17.11
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Landsat Image of Sedimentation of the Potomac River near
Washington D.C.
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.15
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.17
(a)
(b)
(c)
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Conservation Tillage in the US
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Vegetative Barriers
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.24
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.25
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.26
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.27
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.28
(a)
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
(b)
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.30
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.32
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Dust Storm in Texas
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.33
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Suspension and Saltation of Soil Particles
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Factors Affecting Wind Erosion
• Wind Velocity
– Rate of wind movement especially gusts.
• Wind Turbulence
– Chaotic energy of wind flow.
• Surface Roughness
– Rough surfaces reduce the wind speed and erosion.
• Soil Properties
– Moisture content, mechanical stability, soil crust, bulk
density, and soil particle size
• Vegetation
– Increases surface roughness, provides sediment traps,
and holds soil in place
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.36
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Figure 17.37
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Land Capability Classification
• Land Capability Classification
• Eight classes (I-VIII) indicating the degree
of limitation.
– Subclasses
• e – risk of erosion
• w – wetness, drainage, and flooding
• s – root-zone limitations; acidity, density, and
shallowness
• c – climate limitations
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Land Capability Classes in San Mateo County, California
(focusing on erosion hazards)
Figure 17.38
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Geographic Soils Information
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Scale of Soil Variability
• Small-Scale Soil Variability
– Variation occurs at the fine-scale even within a pedon.
• Medium-Scale Soil Variability
– Variability across the landscape is often driven by
changes in parent material or topography.
• Large-Scale Soil Variability
– At the broadest scale soil patterns are principally driven
by climate and vegetation patterns
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Soil Sampling Techniques
THE NATURE AND PROPERTIES OF SOILS, 13/e
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©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Ground Penetrating Radar
THE NATURE AND PROPERTIES OF SOILS, 13/e
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©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
Global Positioning Systems
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
GPS in Precision Farming
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
RS and Absorption Bands
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
THE NATURE AND PROPERTIES OF SOILS, 13/e
Nyle C. Brady and Ray R. Weil
©2002 Pearson Education, Inc.
Upper Saddle River, New Jersey 07458