List of factors
affecting the properties

Within the framework of the revision of the questionnaire of the Periodic Reporting exercise (Section II) in 2008, the World Heritage Committee adopted a standard list of factors affecting the Outstanding Universal Value of World Heritage properties.

This list was established following a 2-year consultation process with experts in both fields of natural and cultural heritage. It consists of a series of 14 primary factors, encompassing each a number of secondary factors.

In the state of conservation reports examined by the World Heritage Committee, threats affecting the Outstanding Universal Value of the properties are indicated in a narrative form (e.g. “to evaluate the seriousness of the threat posed by the proliferation of Typha australis and other invasive aquatic species” in the 2005 report on Djoudj National Bird Sanctuary – Senegal) to be as precise as possible and site-specific.

However, to have a consistent approach for all the properties examined throughout the different processes, the regions of the World and the categories of heritage (natural, mixed and cultural), the treatment of those factors/threats requires certain homogeneity. For this reason, the standard list of factors/threats identified in Section II of the Periodic Reporting was also used in the State of conservation Information System, and each narrative description of a threat in a state of conservation report was linked into the corresponding standardized factor. For example, the above-mentioned threat for Djoudj National Bird Sanctuary in Senegal, was linked to the standard factor: “Invasive / alien freshwater species”. This standardization makes the analysis of potential trends over the years or across regions more consistent.

Lastly, it is worth noting that in the online Information System on the state of conservation of World Heritage properties, the threats are presented in alphabetical order, irrespective of their type (“ascertained danger” or “potential danger”). Should the property be threatened by serious and specific danger, the World Heritage Committee can decide to inscribe this property on the List of World Heritage in Danger.

The 14 primary threats

The standard list of threats/factors affecting the Outstanding Universal Value of World Heritage properties consists of a series of 14 primary factors, encompassing each a number of secondary factors.

Buildings and Development

Housing

For example:

Urban high rise/urban sprawl
Encroachment/changes to skyline etc.

Commercial development

For example:

Skyscrapers
Large shopping malls
Encroachment/changes to skyline etc.

Industrial areas

For example:

Individual factories
Industrial areas/parks
Encroachment/changes to skyline etc.

Major visitor accommodation and associated infrastructure

For example:

Major accommodation and associated infrastructure (hotels, restaurants, golf courses, ski resorts, etc.)
Major/permanent high cost tourism facilities (pontoons, jetties, observatories, cable cars, chalets, fully serviced camping areas, etc.)

Interpretative and visitation facilities

For example:

Visitor interpretive facilities (visitor centre, site museum, etc.)
Signage etc.
Trail hardening, (trail markers etc.)
Information booths etc.
Minor picnic facilities
Minor camping areas
Moorings/marker buoys

Transportation Infrastructure

Ground transport infrastructure

For example:

Roads
Car parks
Railways, including easements
Transport depots

Air transport infrastructure

For example:

Airports
Airstrips

Marine transport infrastructure

For example:

Harbour & port facilities

Effects arising from use of transportation infrastructure

For example:

Effects of vehicle traffic on roadways
Effects of shipping traffic in shipping routes
Effects of air traffic

Underground transport infrastructure

Utilities or Service Infrastructure

Developments in relation to infrastructure for energy utilities (i.e. gas, electricity and water) and other service requirements

Water infrastructure

For example:

Dams
Locks
Weirs
Water tanks
Pumping stations
Introduction of new systems/ infrastructure

Renewable energy facilities

For example:

Thermal
Wave
Solar
Wind

Non-renewable energy facilities

For example:

Nuclear power plants
Coal power plants
Oil/gas facilities

Localised utilities

For example:

Incinerators
Cell phone towers
Sewerage works
Microwave/TV/radio towers

Major linear utilities

For example:

Power lines/easements
Pipelines etc.
Channels

Pollution

All types of pollution (residential or commercial) as well as garbage, solid waste.

Pollution of marine waters

For example:

Ocean dumping
Bilge water discharge
Solid debris in marine environments

Ground water pollution

For example:

Oil/chemical spills
Industrial effluent
Agricultural runoff
Household sewage/waste
Acid sulphate soils
Effluent discharge
Mine/tailings runoff

Surface water pollution

For example:

Acid rain
Mine/tailings runoff
Agricultural runoff

Air pollution

For example:

Excessive smoke or other airborne particulates
Dust
Local effects of emissions from use of fossil fuels

Solid waste

For example:

Mine tailings
Litter
Industrial waste
Household rubbish

Input of excess energy

For example:

Any inputs of heat and light that disturb ecosystems including inappropriate urban lighting, heat pollution, etc.

Biological resource use/modification

The collecting/harvesting of wild plants and animals (forestry, fishing, hunting and gathering) and harvesting domesticated species (silviculture, agriculture and aquaculture)

Fishing/collecting aquatic resources

For example:

Trawling

Netting
Line fishing
Game fishing
Collection/harvest fisheries
Spearfishing
By-catch/incidental take issues

Aquaculture

For example:

Marine
Freshwater aquaculture

Land conversion

For example:

Agriculture (crops and livestock)
Rural
Forestry

Livestock farming/grazing of domesticated animals

For example:

Grazing on farms or by pastoral groups

Crop production

For example:

Deep ploughing
New crops
Intensification of planted agriculture
Traditional crops
Traditional systems
Gardening

Commercial wild plant collection

For example:

Pharmaceutical trade
Medicinal plants
Fodder collection
Thatching
Mushrooms
Bulbs etc.

Subsistence wild plant collection

Use this question for Indigenous subsistence hunting, gathering and collecting, i.e. not for economic benefit, for example:

Food plants
Medicinal plants
Fodder collection
Thatching
Mushrooms
Bulbs etc.

Commercial hunting

For example:

Bush meat trade
Organised game hunting

Subsistence hunting

Subsistence, i.e. not for economic benefit, hunting. Use “Indigenous hunting, gathering and collecting” to indicate factors relating specifically to Indigenous hunting, gathering and collecting

Forestry /wood production

For example:

Logging
Pulp production
All silvicultural operations
Restoration/regeneration
Sustainable wood harvesting

Physical resource extraction

If illegal see “Other human activities”

Mining

Quarrying

For example:

Rock
Sand
Aggregates

Oil and gas

Water extraction

Local conditions affecting physical fabric

Environmental or biological factors that promote or contribute to deterioration processes of the fabric of heritage sites. Since effects of decay cannot be attributed to a single factor, consider all elements.
Use “Air pollution” for air pollution.
Use “Climate change and severe weather events” for severe weather, including flooding.
For tourism activities “Impacts of tourism/visitor/recreation”.

Wind

For example:

Erosion
Vibration

Relative humidity

Temperature

Radiation/light

Dust

Water (Rain/Water table)

Pests

Micro-organisms

Social/cultural uses of heritage

Social factors that contribute to deterioration processes of the fabric of heritage sites. Some uses might have a positive impact as they enhance certain values (e.g. ritual, religious) while others might compromise ascribed values and could lead to the deterioration of the heritage site.

Use “Major visitor accommodation and associated infrastructure” and “Interpretative and visitation facilities” for impacts of tourism infrastructure and tourism activities in “Impacts of tourism/visitor/recreation”.