This glossary is in the process of being updated and has been compiled from numerous other sources including the OpenStreetMap Wiki site and a guide written by Will Skora. Feel free to help us update it by reviewing for how to contribute to the site. Reviewed 2015-07-18

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3W : Who, What, Where; Who does What, Where?

AAR : After Action Review; A group activity to evaluate an exercise or activity to learn and improve.

Activation (HOT term) : Sometimes referred to as a crisis, disaster, or emergency response and generally characterized by a specific event and/or anticipated humanitarian impact with a relatively shorter time-frame associated with the response and recovery phases of the disaster cycle than a longer-term Humanitarian Project.

Activator(s) : HOT volunteers who have completed training and are endorsed by an existing activator to perform roles during events.

AOI : Area of Interest ; defined by activation coordinators in consultation with humanitarian partners, field teams and HOT community in wake of a disaster.

Changeset: A group of changes that you made to OSM data. Once uploaded to OSM, your edits are instantly available to others if they download them. They may take a few minutes or several hours to appear on the map.

COD : Common Operational Database ; Comprises the geographical data for multiple humanitarian activations. These are mainly: transportation network (roads, bridges/fords, ports etc.), populated places (settlements), administrative boundaries, hydrology (rivers and other bodies of water) and hypsography (elevations/contours). May include buildings as an indirect source of population statistics. Used by the United Nations Office for the Coordination of Humanitarian Affairs.

DHN : Digital Humanitarian Network ; organization which leverages digital network for humanitarian response.

DWG : Data Working Group ; composed of people who have a solid editing history and who are in charge of constructive interaction with the OSM community, problem-solving with others, repairing damage and writing changeset comments, also following the day-to-day work, to ensure the validity of the OSM data and make a positive contribution to decision making.

Extract : OSM Data Overview A large chunk of OSM data for a specific area (like a state, country, or geographic area).

Field Papers: is a web-based tool for easily creating a printable map atlas for anywhere in the world that you can print and add notes to. See for more details.

FOD : Fundamental Operational Database ; data that is specific for to activation i.e. health facilities, schools, water facilities, flood extents, building damages, etc.

GDACS : Global Disaster Alert and Coordination System ; GDACS is a cooperation framework under the United Nations umbrella. It includes disaster managers and disaster information systems worldwide and aims at filling the information and coordination gap in the first phase after major disasters. GDACS provides real-time access to web‐based disaster information systems and related coordination tools.

GPS/GNSS : Global Positioning System (GPS)/ Global Navigation Satellite System (GNSS) ; It is an umbrella term for all global satellite positioning systems.

iD editor - Web-based beginner-friendly OpenStreetMap editor designed by Mapbox.

IDP : Internally Displaced Person ; is a person that is forced to flee his or her home while continuing to remain within their country’s borders.

JOSM pronounced “Jaws-um”, OpenStreetMap editor written in Java.

Layer: A data source that’s displayed on a slippy map (often is thought of as a group of tiles stitched together).

Mapper ; person of the OSM community who contributes to the creation or digital update of the database and provides solutions to notes and inconsistencies.

NGO : Non Govermental Organisation / Agency ; primarily a not for profit compulsory group of citizens who are organized on a local, national or international level.

Node: A node is one of the core elements in the OpenStreetMap data model. It consists of a single point in space defined by its latitude, longitude and node id. Nodes can be used to define standalone point features, but are more often used to define the shape or “path” of a way.

OCHA : United Nations Office for the Coordination of Humanitarian Affairs ; OCHA is the part of the United Nations Secretariat responsible for bringing together humanitarian actors to ensure a coherent response to emergencies. OCHA also ensures there is a framework within which each actor can contribute to the overall response effort.

POC : Point of Contact ; person(s) to engage with for any enquiries, questions, coordination, etc.

Relation: one of the core data elements that consists of one or more tags and also an ordered list of one or more nodes, ways and/or relations as members which is used to define logical or geographic relationships between other elements. For examples go to the Types of Relations wiki page.

Render : to convert from data into an image. Rendered data is a map.

SBTF : Stand-By Task-Force ; an organization which coordinates digital volunteers into a responsive, trained, and prepared network ready to deploy in crises.

Slippy Map : What you see when you’re on ! Consists of a layer and a software library that controls interactive features like zooming & panning.

Stylesheet : In most instances, it means a text file that’s used to determine what features (which roads ?) are displayed, and how (what color should the road be ? Its width ? ) on a map.

Tag: Tags describe a point, line or polygons. Each tag contains a key and value (written in OSM as ‘key=value’). For example, highway=residential and name=Woodland Avenue. Initially mentioned in Learnosm within iD section A Point, line, or polygon usually have more than one tag on them. Sometimes choosing the right tag is confusing. Taginfo helps you by showing statistics about which tags are actually in the database, how many people use those tags, where they are used and so on. It also gets information about tags from the wiki and from other places.

TIGER : A data source from the US Census Bureau that was imported into OSM, in 2007. This is the source for most data in the USA in OSM.

Tile : a small image (256x256 pixels ) of rendered map data.

Way: an ordered list of nodes which normally also have at least one tag or is included within a Relation. A way can have between 2 and 2,000 nodes, although it’s possible that faulty ways with zero or a single node exist. A way can be open or closed.

  • A closed way closedwayimage is one whose last node on the way is also the first on that way. A closed way may be interpreted either as a closed polyline, or an area, or both.

  • An open way openwayimage is way describing a linear feature which does not share a first and last node. Many roads, streams and railway lines are open ways.

Disaster Types:

The following list is the nomenclature for Disaster Types adopted at HOTOSM for disaster response. It is a direct reference from ReliefWeb (with minor amendments)* and is used by the promotors of the GLobal IDEntifier Number (GLIDE) initiative:

Cold Wave (GLIDE hazard code: CW): Cold Wave is defined as a period of abnormally cold weather. Typically a cold wave lasts two or more days and may be aggravated by high winds. The exact temperature criteria for what constitutes a cold wave vary by location. (CRED EM-DAT)

Drought (GLIDE hazard code: DR): Drought is defined as an extended period of unusually low precipitation that produces a shortage of water for people, animals and plants. Drought is different from most other hazards in that it develops slowly, sometimes even over years, and its onset is generally difficult to detect. Drought is not solely a physical phenomenon because its impacts can be exacerbated by human activities and water supply demands. Drought is therefore often defined both conceptually and operationally. Operational definitions of drought, meaning the degree of precipitation reduction that constitutes a drought, vary by locality, climate and environmental sector. (CRED EM-DAT)

Earthquake (GLIDE hazard code: EQ): Earthquake is defined as sudden movement of a block of the Earth’s crust along a geological fault and associated ground shaking. (CRED EM-DAT)

Epidemic (GLIDE hazard code: EP): Epidemic is defined as either an unusual increase in the number of cases of an infectious disease, which already exists in the region or population concerned; or the appearance of an infection previously absent from a region. (CRED EM-DAT)

Extratropical Cyclone (GLIDE hazard code: ET): Extratropical Cyclone is defined as a type of low-pressure cyclonic system in the middle and high latitudes (also called mid-latitude cyclone) that primarily gets its energy from the horizontal temperature contrasts (fronts) in the atmosphere. When associated with cold fronts, extratropical cyclones may be particularly damaging (e.g. European winter/windstorm, Nor’easter). (CRED EM-DAT)

Fire (GLIDE hazard code: FR): Fire is defined as urban, industrial or rural fires, linked to natural phenomena, such as electrical storms, earthquakes, droughts, etc.but not including wild fires, which refer to uncontrolled fire in rural areas, forests, plains, etc. Directly human-induced fires are classified as Technological Disaster.

Flash Flood (GLIDE hazard code: FF): Flash Flood is defined as rapid inland floods due to intense rainfall A flash flood describes sudden flooding with short duration. In sloped terrain the water flows rapidly with a high destruction potential. (CRED EM-DAT)

Flood (GLIDE hazard code: FL): Flood is a general term for the overflow of water from a stream channel onto normally dry land in the floodplain (riverine flooding), higher-than- normal levels along the coast and in lakes or reservoirs (coastal flooding) as well as ponding of water at or near the point where the rain fell (flash floods). (CRED EM-DAT)

Heat Wave (GLIDE hazard code: HT): Heat Wave is defined as a prolonged period of excessively hot and sometimes also humid weather relative to normal climat patterns of a certain region. Heat waves like in Central Europe 2003. (CRED EM-DAT)

Insect Infestation (GLIDE hazard code: IN): Insect infestation is defined as the pervasive influx and development of insects or parasites affecting humans, animals, crops and materials. (CRED EM-DAT)

Landslide (GLIDE hazard code: LS): Landslide is defined as the usually rapid downward movement of a mass of rock, earth, or artificial fill on a slope. Covers all mass movements other than Mudslide (MS) and Avalanche (AV). (CRED EM-DAT)

Mudslide (GLIDE hazard code: LS): Mudslide is defined as a type of landslide, which occurs when the slope is saturated with water. This more destructive flow can pick up rocks, trees, houses and cars. As the debris moves into river and stream beds, bridges can become blocked or even collapse, making a temporary dam that can flood neighbouring areas. (GLIDE)

Other (GLIDE hazard code: OT): Other is defined as all natural disasters that do not fall into any of the other disaster types. Special situations such as energy crisis, etc.

Severe Local Storm (GLIDE hazard code: ST): A severe storm or thunderstorm is the result of convection and condensation in the lower atmosphere and the accompanying formation of a cumulonimbus cloud. A severe storm usually comes along with high winds, heavy precipitation (rain, sleet, hail), thunder and lightning.

Snow Avalanche (GLIDE hazard code: AV): Snow Avalanche is defined as mass of snow and ice falling suddenly down a mountain slope and often taking with it earth, rocks and rubble of every description. (CRED EM-DAT)

Storm Surge (GLIDE hazard code: SS): Storm Surge is defined as the rise of the water level in the sea, an estuary or lake as result of strong wind driving the seawater towards the coast. This so-called wind setup is superimposed on the normal astronomical tide. The mean high water level can be exceeded by five and more metres. The areas threatened by storm surges are coastal lowlands. (CRED EM-DAT)

Technological Disaster (GLIDE hazard code: AC): Technological disasters are only covered on a very exceptional basis, such as oil/toxic spills and gas explosions, when they have a major humanitarian impact in highly vulnerable countries.

Tropical Cyclone (GLIDE hazard code: TC): “Hurricane”, “cyclone” and “typhoon” (GLIDE hazard code: TC) are different terms for the same weather phenomenon which is accompanied by torrential rain and maximum sustained wind speeds (near centre) exceeding 119 kilometers per hour: In the western North Atlantic, central and eastern North Pacific, Caribbean Sea and Gulf of Mexico, such a weather phenomenon is called “hurricanes”; In the western North Pacific, it is called “typhoons”; In the Bay of Bengal and Arabian Sea, it is called “cyclones”; In western South Pacific and southeast India Ocean, it is called “severe tropical cyclones”; In the southwest India Ocean, it is called “tropical cyclones.” (WMO)

Tsunami (GLIDE hazard code: TS): Tsunami is defined as a series of waves (with long wavelengths when traveling across the deep ocean) that are generated by a displacement of massive amounts of water through underwater earthquakes, volcanic eruptions or landslides. Tsunami waves travel at very high speed across the ocean but as they begin to reach shallow water they slow down and the wave grows steeper. (CRED EM-DAT)

Volcano (GLIDE hazard code: VO): Volcanic eruption with disastrous effects: eruption and emission of gas and ashes, stone falls (pyroclast), flows of lava, etc.

Wild Fire (GLIDE hazard code: WF): Wild Fire is defined as ny uncontrolled and non-prescribed combustion or burning of plants in a natural setting such as a forest, grassland, brush land or tundra, which consumes the natural fuels and spreads based on environmental conditions (e.g., wind, topography). Wildfires can be triggered by lightning or human actions. (CRED EM-DAT)

*Mud Slide to Mudslide and Land Slide to Landslide. More information on disaster classification at CRED EM-DAT.

Note on OSM Editing Terms:

Many terms to describe map features in OSM are used in dialects of British English and spelled as such. Like neighbourhood.

Motorway: British English term for the most major highway, also considered as ‘freeway’

Pitch : used to describe a playing field. Including tennis courts, basketball courts, baseball diamonds, or football fields.