Locality and Georeferencing Sources

The following are the most common sources of locality and georeferencing tools that we use for Mandala. Links to the tools below as well as others, are available on a tab in Mandala’s LOCALITY table. Users can link to this discussion or various online gazetteers. Links to screen captures from the database may be expanded to a larger size for better viewing (using a grow box in the lower right of each screen; note javascript must be enabled to view images).

In retrospective input of data from existing collections, it is essential to input the verbatim information from a locality label to facilitate proofing and to backcheck for possible errors in interpretation of the locality data when it is parsed in LOCALITY. A complete verbatim label would include all the information that we could possibly look up at this time, including elevation, county, and latitude/longitude.

The reality is that insect labels, being as minute as the insects themselves, are often far from complete. In addition, political boundaries change and often their names change as well. Add to that local variations in orthography, poor spelling habits, and transcription errors of some collectors, and there can be quite a puzzle to unravel to arrive at a good approximation of the locality. The information entered into LOCALITY is our current concept of where a specimen was collected, keeping in mind and in hand, the original verbatim label. We can use one of the tools below (or ones listed in the LOCALITY table of Mandala) to expand our knowledge, adding country, county, latitude, and longitude. Or if we know the collector(s), we may also know that elevation, latitude, and longitude that are printed on the label were all obtained via a GPS (global positioning satellite) device, using a designated geodetic datum, even though it is not directly stated on the label. In such cases, we will state that the source of the data was from a GPS, over simply saying that the information was on the label. In either case, these measurements have not been cross-checked with other sources for accuracy unless errors appear glaring (e.g., specimen geocoded for the middle of the ocean or entirely different biogeographic region than others collected for that species), and are discovered through mapping.

The following list discusses some of the pros and cons of using one tool over another. Mandala has links to other tools that may be more country or region-specific that are not included below.

Google Maps is one of the fastest growing mapping devices available on the web, with its sister Google Earth, which requires downloading of an application to your computer. But while you may pinpoint exactly where you picked up a particular prized specimen, you need a piece of javascript to translate the center of your map into latitude and longitude coordinates. Don’t be lured by the number of decimal places returned. It is very doubtful that retrospective georeferencing deserves such precision, unless you know the area well and you and your target organism did not move.

Also working with Google Maps is BioGeomancer’s Workbench.

U.S. Geological Survey: USGS finds the coordinates of many different features in the United States and its territories, including municipalities, rivers, canyons, woods, plains, etc. A query can contain any or all of the following entries: feature name, state name, county name, or feature type. USGS will return all results it finds in its databases with the matching descriptions. Sometimes more than one result is returned. In this case, in order to see specific details about your desired feature, you may have to click on its name (if it is highlighted in blue). The lat/long coordinates are given in a table as strings of numbers; the first set of numbers are degrees, the next two numbers are in minutes, and the last two numbers are in seconds. The correct spelling is necessary to return any pertinent information. Sometimes, in addition to lat/long information, elevation is also given in feet. If there is a displacement (i.e. 7 km N Chicago), this elevation cannot be used. Sometimes a city will have multiple lat/long listings. For example, searching for “Los Angeles” will return 19 lat/long listings because it is such a large city.

If a query does not return any results, but specific information is known about the locality, this information can be input with a hope of returning the correct result. For example, if the label reads “Great Malt Lake, Davis County, Utah”, no results are found with this query. However, if you input “Feature Type=Lake, County=Davis, and State=Utah”, and compare the label with the results (2 results are returned, “Great Salt Lake” and “Farmington Lake”), you will find “Great Salt Lake” is very close to the label. These interpretations are recorded in a geocoding comments field that track assumptions made in the interpretation of labels while geocoding.

NGA (formerly NIMA) is the National Geospatial Intelligence Agency’s database of international geographic feature names. It is used to find latitude and longitude information for features outside of the United States. Although the website for entering queries can be rather intimidating looking, with many windows and frames, you can input the locality name under “Query Criteria”, and select the desired country below that. You can specify feature types (i.e. rivers, canals, etc.), but if you do not specify any, all areas are searched. You must specify a country or latitude/longitude area for the search.

Australian Gazetteer. This internet site from the Australian National Mapping Agency is useful for Australian territories, giving latitude, longitude, feature type and territory information. Searches can be general (i.e. searching a name for all feature types and in all of Australia), or more specific (i.e. searching a name for a beach in Tasmania). Latitude and longitude are given in degrees, minutes, and seconds.

Geographical Names of Canada is an internet site similar to the Australian Gazetteer, except for Canada from the Canadian Permanent Committee on Geographical Names. Searches can be general (i.e. searching a name for all feature types in all of Canada), or more specific (i.e. searching a name of a lake in Ontario). After the results are returned, click on the “Details” button to obtain more detailed information. The latitude and longitude values are given in degrees, minutes, and seconds.

Getty Thesaurus of Geographic Names (TGN). Getty Information Institute, Los Angeles, California is a comprehensive, international gazetteer of over 900,000 place names. You can search on a single feature without a country name. It returns the continent, nation, state, county, latitude and longitude in degrees and minutes with direction. Geographic coordinates for most places represent the center of that place. For rivers or streams, the source is referenced. TGN also references the source of its information. Names also contain flags that indicate usage: C for current name; H for historical name; V for vernacular name; and O for a variant name in a language other than the vernacular. Made for studies of art history, these variations in usage can be a boon for names no longer used or whose common spellings vary.

Tiger Maps give you zoomable maps of areas in the USA. Because the maps take time to load in your browser and it can be difficult to orient yourself, this site is most useful for displacement measurements from specified target (e.g., 6 km E of Cloverly, on route 650), in particular those along a specific feature (e.g., along a road or stream). The city and state names are entered at the bottom of the webpage, and latitude and longitude values are returned in decimal format and you can click and see a map of the area. From this map, zoom in or out, and ask to see streets, highways, etc. You will need to use the compass and the scale given below the map on the site to measure the distance from a given point. We use the pinpoint of the municipality or specific area positioned by the program as our basis of the measurement. When we used Tiger Maps for geocoding displacements, we tried to have our measurement follow a major road from the area we were using as our base.

If displacement is stated as along a particular feature (stream, river, road, etc.) that is not straight or gives no indication of direction, either Tiger Maps or Encarta must be used. However if there is no indication of feature along which the measurement was made, we are assuming an “as the crow flies” displacement from a point. Here we can now use the calculator for displacement in the LOCALITY database to automatically calculate the displacement.

Fuzzy Gazetteer is a useful tool when you suspect that the place name may have been misspelled or truncated. Because many of the gazetteers are unforgiving when it comes to spelling, this is a welcome addition (thanks, Doug Yanega for pointing it out!) to the georeferencer’s bag of tricks.

Microsoft Encarta Virtual Globe/Earth: This CD-based tool was primarily available in the late 1990s before the spread of other online gazetteers. It is included here primarily to describe why it was used early on in Mandala’s development and why it might be of use in areas where on-line access is difficult or limited. This PC-only tool acted as an interactive world atlas that displayed latitude, longitude, and county names but not elevation. Place name searches returned all entries that had a spelling close to that of your query, making it especially useful where information had been misspelled or was difficult to read on the label. After choosing the desired result, a map appeared with the locality in the center of the map. Zooming in could better pinpoint the lat/long information. Latitude and longitude data could either be displayed as decimals or in degrees-minutes-seconds. The Encarta Virtual Globe also contained a measuring tool that was cumulative along irregular features such as coastlines.

Many thanks to Andrea Gavurnik, Jessica Bickham,
Kristin Algmin, Amanda Buck & Ravi Solter
for their background work on our geocoding methods.