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; Soils = soilscape = geopedological setting.

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Presentation on theme: "; Soils = soilscape = geopedological setting."— Presentation transcript:

1 ; Soils = soilscape = geopedological setting


3 INTRODUCTION: Soil definition
“A natural body consisting of layers (or horizons) of mineral (and/or organic constituents) of variable thickness, which differ from the parent material in their morphological, physical, chemical, and mineralogical properties and their biological characteristics” S = f (Cl, O, R, P, T,……M)

4 Definition : A soil = “pedon” is the smallest volume with a surface extent which varies from about 1 to 10 m²” Soil sample Pedons/ polypedons in ‘soilscape’

5 Definition: Pedon / polypedon
For mapping purposes, similar pedons are pooled together, forming a polypedon, obviously associated with variability, depending on scale

6 Functions: What does soil do?
1- Soil provides the required setting for water, nutrient, air, and heat exchange for living organisms. 2- Soil controls the water distribution;affects the movement of soluble materials. 3- Soil regulates biological activity and molecular exchanges among solid, liquid, and gaseous phases. 4- Soil acts as a filter to protect the quality of water, air, and other resources.

7 What does soil do? 5- Soil provides mechanical support for living organisms and their structures. People and wildlife depend on this function. 6- Soils act: - as an archive (=history book of the landscape), - as a guide, and - as a ‘predictor’

8 Soils speak out; an account of
THEORETICAL BACKGROUND AND ILLUSTRATIVE EXAMPLES Soils speak out; an account of the past, present, and future

9 An account of the past, present, and future
Past  Paleoecology Present  Soil Management Future  Soil Degradation/ Conservation

10 Past: Paleoecology

11 History book of the landscape (archive)
Examples of features revealing paleoecology: Pedogenic (horizons): * Anthropic, * Plaggen, etc * Argillic, *Agric, etc 2. Geomorphic (features): * Glacis formation:Tunisia, Morocco * Travertine (karstic): Iran

12 1. Pedogenic (horizons)

13 2. Geomorphic; glacis formation 2.1 Tunisian example:
Pedimentation/ planation : in practice, erosional glacis – adjacent to the mountain front— is followed by an accumulation glacis. A fan distinguishes itself from the glacis by being associated with a distributary (dichotomic) drainage pattern .

14 2. Geomorphic; glacis formation 2.2 Moroccan example
Erosional glacis terraces Accumulation glacis

15 2. Geomorphic; glacis formation 2.3 Iranian example
Stereogram depicting glacis Pedostratigraphy (approving)

16 2. Geomorphic features Karstic springs; Travertine
Karst spring (dried out) Travertine in scattered patches

17 Microgram of travertine speciman

18 Iran: A wetter climate, karstic springs where travertine is spread out; Once upon a time (27000 yr BP yr BP) the study area was subject to cycles of erosion and sedimention, also approved by the occurrence of Argillic and Petrocalcic horizon ; Aridification has never been as degrading as it is today Morocco: Occurrence of Ultisols and Plinthite implies a wetter and hotter climatic condition Different vegetation cover

19 Present: Soil- management

20 Present: Soil Management
Guiding features: *Soil properties (Physico-chemical): particle size class, depth, pH,…… *Position in landscape (Site)

21 When well managed Traditional wooden device for plowing; pulled by oxen

22 When mis-managed

23 Future: Prediction ”A soil survey describes the characteristics of the soils in a given area, classifies the soils according to a standard system of classification, plots the boundaries of the soils on a map, and makes predictions about the behavior of soils.”(SSM, 1993)

24 Future : Prediction regarding (possible) land degradation
Guiding features: Pedon (individual soil body) Diagnostic soil characteristics - Abrupt textural change - COLE (coefficient of Linear Extensibility) - (Para-) Lithic contact,……..


26 Change of erosion base-level: gully formation and landslide
Bushes hold soils together Landslide Gully running perpendicular Landslide It is clearly seen that the gully in the bottom of the vale (fig c) is triggering; landslide has occurred once the slope has been de-bushed (cleared) The gully Fig. c

27 Gullies formed Bush land Cereals Boundary between 2 soil series Gully
Ploughed for Vine tree plantation

28 Incision (gully) occurs in a joint, the weakest line between two pedons

29 If you want to conserve the environment
CONCLUSION: If you want to conserve the environment Listen to what soils say Prevention is better than cure

30 Is check-dam solving the problem?!
Water goes like this; neglecting the dam Check-dam does not help Slump Second trial The first check dam



33 Buol, S. W. , Hole, F. D. , and R. J. McCracken. 1973
Buol, S.W., Hole, F.D., and R.J. McCracken Soil Genesis and Classification. The Iowa State University Press, Ames. Farshad, A Introduction to Applied Geomorphology for Soil Scientists (Geopedologists). Lecture-notes, Department of Earth System Analysis (ESA), ITC, Enschede, The Netherlands. Rferences Rosa M.Poch (editor- in- Chief) and Kovda, Irnia and Curtis Monger (Guest editors) st volume of the proceedings of the 14th IWMSM. Departament de Medi Ambient i Ciències del Sòl Universitat de Lleida Av. Rovira Roure 191, Lleida (Catalonia) USDA, Soil Taxonomy, A Basic System of Soil Classification for Making Interpreting Soil Surveys. Soil Survey Staff. Agricultural Handbook No. 436. Zinck, G.A. 1988/89. Physiography and soils; soil survey courses (Lecture-notes) , ITC, Enschede, The Netherlands.

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