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Headline
Indicators
Author: Nichola Geeson <desertlinks@medalus.demon.co.uk>
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Definition of a headline indicator
Headline indicators are mentioned
in many indicator systems, as the key indicators, the most important indicators,
summary indicators, or indicators useful to make headlines in the media.
The European Environment Agency suggest that "The purpose of environmental
headline indicators is to provide simple and clear information to decision-makers
and the general public about progress in environmental policies and the
key factors determining the state of the environment and whether we are
moving towards environmental sustainability." Desertification headline
indicators should have a similar purpose.
Although we have the definition above,
headline indicators may still not always have the same meaning. The EEA
use of headline indicators includes conferring the term headline on broad
headings or broad summaries of lists of specific problems, e.g. soil degradation,
climate change. In DESERTLINKS we have been seeking key headline indicators
that can be defined and measured in the same way in adjacent areas or
countries to provide a credible basis for comparison and monitoring change.
They may be already in widespread use in the countries of Annex IV, or
be additional indicators selected to further enhance a common approach.
Headline indicators are often calculated from a collection of indicators
as an index, e.g. soil quality index, climate index, Environmental Sensitivity
Index, Regional Degradation Index.
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Headline indicators already used in
National Action Programmes (see also Using
and combining indicators: National and Mediterranean-wide scales)
Different countries have chosen different
approaches to headline indicators. Some of these are slightly different
to those described within DIS4ME. The headline indicators measured by
Portugal, Spain, Italy and Greece within their National Action Programmes
include:
Greece [1], [2]:
- Soil mapping units. From the ESB
1:1,000, 000 Soil Map of Europe.
- Slope gradient.
Using the CORINE definition
- Bio-climatic index.
Bagnouls-Gaussen definition, derived from the Bioclimatic Map of Greece
(=Aridity index
(1))
- Irrigation intensity and salt seawater
intrusion. Derived
from irrigation work and sea water intrusion map and used to estimate
secondary salinisation risk of irrigated soils.
Italy [3], [4]:
- Aridity index (1). Defined as the
relationship between the average yearly precipitation and the average
yearly potential evapo-transpiration;
- Soil characteristics index. Related
to the pedo-climatic classification of the Italian territory (dependent
on soil and its biotic cover);
- Land use index. Obtained by means
of a reclassification of the original Corine Land Cover classes.
- Demographic variation index. defined
as the percentage of population variation between 1981 and 1991, at
the municipal scale.
- Index of sensitivity to desertification.
Calculated from the four above indices.
Portugal [5]:
Spain [6]:
- Aridity index (2). Penman
definition. Mean annual precipitation /mean annual potential evapotranspiration
- Soil Loss Index (USLE). Soil
erosion as calculated by the USLE T/haˇyears
- Forest and wild fires. Percentage
of the land surface area affected by fire over a 10 year period.
- Drought. Percentage
of the normal mean annual precipitation values.
- Aquifer over-exploitation. Ratio
of pumping to recharge rates.
- Desertification
index. Calculated from the five above indices.
These countries all include some sort
of bioclimatic or aridity index and an index related to soil type or soil
loss by erosion. Other headline indicators or indexes relate to the desertification
issues that cause the most problems in those countries e.g. drought, fire,
salinisation or flood risk.
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Headline indicators in DIS4ME
A consensus on the definition and
use of standard headline indicators across southern Europe has not yet
been achieved. If a wide range of data or information is available, then
the four quality indexes for climate, soil, vegetation and management
are good comparative headline indicators, and often coincide with existing
national use of headline indicators. A wide range of alternative indicators
is available according to data availability. Some headline indicators
relate to a particular desertification issue and others relate to several
desertification issues.
The table below lists some examples.
Issue |
Headline indicator |
Comment |
All issues |
Individual climate, soil, vegetation
and management quality indexes |
If full data for combined indexes
is not available, similar or component indicators may be used. |
|
Environmental
Sensitivity Index, including rainfall, aridity index, aspect,
drainage, soil depth, rock fragments, soil texture, soil parent material,
slope gradient, type of vegetation, plant cover, soil erosion protection,
drought resistance, policy enforcement and land use intensity. |
The component indicators of the
Environmental Sensitivity Index can be used as a basic set of indicators. |
|
PESERA-RDI (**
insert link) (Pan European Soil Erosion Risk Assessment - Regional
Degradation Index). A physically based estimate of erosion risk, (combining
erosivity, a topographic index and soil erodibility) for the whole
of Mediterranean Europe at a 1 km resolution. |
Addition of salinisation and
fire risk components has improved the accuracy of the original map. |
Land abandonment |
Land
abandoned from agriculture
Area of cultivated and semi-natural vegetation (rs) |
Abandoned land is not managed,
and structures to protect against soil erosion may not be maintained |
Intensive irrigation |
Land
use type
Irrigation
potential realised |
These indicators may suggest
whether irrigation is over-exploited and likely to result in degradation
including salinisation. |
Overgrazing |
Grazing
intensity |
Depending on other factors such
as soil depth, slope angle, local thresholds of grazing intensity
suggest risk of desertification. |
Deforestation |
Deforested
area
Vegetation cover
Biodiversity
conservation
Area of cultivated and semi-natural vegetation (rs) |
Deforestation carries a risk
of increasing soil erosion and desertification, unless it is managed
to preserve vegetation cover. |
Littoralisation |
Tourism
intensity
Population
growth rate
Urban sprawl
Water scarcity
Water
consumption by sector
|
Measures of the significance
of increasing pressures on land near the coast. |
Agricultural practices |
Net
farm income
Land use evolution
Tillage operations
Farm size |
Measures of sustainability of
agricultural practices. |
Economic activity |
Land
use evolution
Population
density
Employment index
Unemployment
rate
GDP per capita
Land use intensity
|
Changes in economic activity
affect land use decisions and therefore affect desertification. |
Land degradation |
Sediment deposition (**
is this in the indicators list?)
Vegetation cover
Soil erosion (** check link to which indicator)
Burned area |
These indicators may have local
ranges or thresholds determining whether desertification is a problem
or not. |
Water resources |
Water
availability
Waste water
recycling
Water quality
Groundwater
depth
Aquifer
over-exploitation
Effective
precipitation |
Many of these indicators have
local ranges or thresholds below which the risk of desertification
is markedly increased. |
Social structure |
Demographic variation index (**
this is not in the indicators list)
Old age index
Population
density
GDP per capita
Adult education
level
Human poverty
index |
These indicators suggest key
ways in which social dynamics may affect desertification. |
Institutional organisation |
Land use policy (**
this is not in the indicator list)
Policy enforcement
|
The risk of desertification is
reduced if national and local policies are in place and enforced. |
Recently some new headline indicators
with summary characteristics have been proposed: Soil
stability index, biological index and river discharge. Soil stability
is related to biological activity in the soil. Stable pores and aggregates
are indicators of the architecture that micro-organisms produce. The biological
index is the number of days that growth is not limited by water and temperature.
River discharge summarises the impact of climate and land use change and
also includes changes in ecosystem activity.
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References
[1] p 13 Second National Report of
Greece on the implemenation of the UNCCD, 2002 http://unccd.int/cop/reports/northmed/national/2002/greece-eng.pdf
[2] p12 Repères et indicateurs. UNCCD, CST, May 2003. ICCDCOP(6)CST5.pdf
[3] p31 Italy National Report, CRIC, November 2002. http://unccd.int/cop/reports.northmed/national/2002/italy-eng.pdf
[4] p29 Repères et indicateurs. UNCCD, CST, May 2003. ICCDCOP(6)CST5.pdf
[5] Lúcio do Rosário (2004) Indicadores de Desertificação
para Portgal Continental. Direcção-Geral dos Recursos Florestais.
http://www.dgrf.min-agricultura.pt
[6] DISMED Technical Workshop on NAP information needs. Spanish NCB report.
DISMED-florence-spain-NCB.rtf
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