|
1. Definition
| Name |
SOIL
QUALITY INDEX |
| Brief definition |
This index
is calculated using classifications of the following parameters:
soil texture, parent material, soil depth to limiting layers,
slope gradient, drainage conditions, and surface rock fragment
cover. |
| Unit of measure |
SQI = (texture*parent
material*rock fragments*depth*slope*drainage)**1/6 |
| Spatial scale |
Regional |
| Temporal
scale |
|
2. Position
within the logical framework DPSIR
3. Target and
political pertinence
| Objective |
To condense
knowledge about soil properties into an index that can be used
on it's own or in conjunction with other quality indexes associated
with desertification. |
| Importance
with respect to desertification |
Soil properties
are a very important factor in terrestrial ecosystems in semi-arid
and dry-subhumid areas, particularly on their effect on biomass
production. |
| International
Conventions and agreements |
A variety of
transboundary legislation exists, as well as EC directives.
The European Commission hopes to "draw up by 2007, in cooperation
with the Member States and the competent regional authorities,
a scientific soil catalogue which should include the nature
of the soil, its biography, health and vulnerability, degradation
and erosion processes and contaminated areas, recognising the
existence of high-value soils (in terms of agriculture, geology,
ecology, history or the countryside) and the need to draw up
recommendations for their conservation and sustainable use;
stresses the importance of harmonising analytical methods to
obtain comparable soil data; the accessibility of existing information
must also be improved, given that this is an important prerequisite
for the necessary exchange of information and experience between
Member States." [(COM(2002) 179 - C5-0328/2002 - 2002/2172(COS)),
2002] |
| Secondary
objectives of the indicator |
To
contribute to an overall measure of sensitivity to desertification
in the classification of Environmentally Sensitive Areas and
the ESI. |
4. Methodological
description and basic definitions
| Definitions
and basic concepts |
Desertification will proceed,
in a given landscape, when the soil is not able to provide
plants with rooting space and/or water and nutrients. In semi-arid
and sub-humid zones land may become irreversibly desertified
when the rootable soil depth is not sufficient to sustain
a minimum vegetation cover. If the problem is water balance
rather than soil depth, desertification may be reversible.
Nutrient supply alone seldom becomes critical in the two climatic
zones mentioned above.
Soil quality indicators
for mapping Environmentally Sensitive Areas can be related
to a) water availability, and b) erosion resistance. The soil
quality indicators (soil texture, parent material, soil depth
to limiting layers, slope gradient, drainage conditions, and
surface rock fragment cover) are available from regular soil
survey reports. For each indicator classes have been defined
with respect to the degree of protection of the land from
desertification. The classes are based on factors such as:
a) soil depth and plant cover under various climatic lithological
and topographical conditions, b) parent material and water
availability, and c) soil water holding capacity and soil
structure.
|
| Benchmarks
Indication of the values/ranges of value |
According to
the class of each soil quality indicator (such as soil texture)
a numerical value is assigned. The geometric mean of the six
soil quality indicators is calculated. Three classes of Soil
Quality Index are then distinguished: high quality, moderate
quality, and low quality. For ranges of weighting indices see
Kosmas, Kirkby and Geeson, 1999. |
| Methods of
measurement |
Soil Quality Index = (texture*parent
material*rock fragments*depth*slope*drainage)**1/6.
For the components of
this calculation, 4 classes of texture, 3 classes of parent
material, 3 classes of rock fragments, 4 classes of slope.
4 classes of soil depth and 3 classes of drainage must be
assessed.
|
| Limits of the
indicator |
The Soil quality
index has been developed particularly for the Greek island of
Lesvos, and the weighting indices may require adjustment for
other areas. |
| Linkages
with other indicators |
Soil
depth, Slope gradient,
Soil texture, Rock
fragments, Drainage, Parent
material, Climate quality
index, Vegetation
quality index, Management
quality index, Aridity index
(1), ESI. |
5. Evaluation
of data needs and availability
| Data required
to calculate the indicator |
Data are required
relating to 4 classes of texture, 3 classes of parent material,
3 classes of rock fragments, 4 classes of slope. 4 classes of
soil depth and 3 classes of drainage. |
| Data sources |
Basic soil
survey information is usually available in a cost-effective
format. |
| Availability
of data from national and international sources |
Data
can be obtained from national agencies and various regional
institutions involved in collecting and processing data. |
6. Institutions
that have participated in developing the indicator
| Main institutions
responsible |
Agricultural
University of Athens, Greece |
| Other
contributing organizations |
Universities
of Lisbon, Murcia, Basilicata |
7. Additional
information
| Bibliography
|
Kosmas, C., Kirkby, M.
and Geeson, N. 1999. Manual on: Key indicators of desertification
and mapping environmentally sensitive areas to desertification.
European Commission, Energy, Environment and Sustainable Development,
EUR 18882, 87 p.
European Commission communication
'Towards a Thematic Strategy for Soil Protection' (COM(2002)
179 - C5-0328/2002 - 2002/2172(COS)), 2002
|
| Other references |
Brandt, J., and Thornes,
J., 1996 Mediterranean Desertification and Land Use. J. Wiley
& Sons, Chichester, England, 554.
Kosmas C., Ferrara A.,
Gerontidis, St. Bellotti B., Detsis V., Faretta S., Mancino
G., and Pisante, M. 1999. A comparative analysis of the physical
environment of two Mediterranean areas threatened by desertifciation.
Mediterraneo M. 127-148.
Conacher, A., and Sala,
M., 1998. Land Degradation in the Mediterranean Environments
of the World: Nature and Extent, Causes and Solutions. J.
Wiley & Sons, Chichester, 491 p.
|
| Contacts
Name and address |
Dr. Constantinos Kosmas
Agricultural University of Athens, Greece
email:lsos2kok@aua.gr
|
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