## Layered Mapping

### Ordnance Survey Ireland

Maths
Geography
Maps are used for decision making in many areas of activity such as flood control, mineral exploration, housing and education. Layered mapping allows the user to place different geo-spatial data sets onto a map in layers. The lesson describes the GeoHive – a web platform that facilitates this process and instructs the student on its use.

Contains the full lesson along with a supporting toolkit, including teachers’ notes.

### Lesson excerpt

There are many different types of map and each type is designed to show particular things. However, every map is an attempt to describe the spatial relationships of chosen features. These might be physical features such as county boundaries, mountains, motorways and the location of towns and cities. Other types of map might be designed to show social or economic information such population density, public transport routes and the location of particular industries.

In modern times, maps are used for decision making and planning purposes in many areas of activity. Flood control, mineral exploration, housing, education, environment, industry, and health are among the almost limitless examples. Obviously, making decisions in these areas requires the consideration of many different types of information. The information comes from various sources. Each of these sources is referred to as geographical information system (GIS) and the data provided is known as geo-spatial data. Clearly it would be extremely useful for decision makers if the data from these various sources could be displayed at the same time on one map. This is exactly what the GeoHive service from OSi offers. In this lesson we will describe GeoHive and learn how to use it to make an important decision.

What is GeoHive?
GeoHive is a web platform (www.geohive.ie) that allows the user to combine chosen sets of geo-spatial data on a map. These data sets can be placed on, and taken off, the map in layers. This process is known as layered mapping.

Using layered mapping
Assume you are moving to a new location and need to know about the schools in the area and how they are served by public transport. The first thing to do is to log in to GeoHive, click the menu button on the top right and select the Make Your Map option. This brings you to the ‘Map Viewer’ where you will see a map  of Ireland. Using the ‘Data Catalogue’ on this page, you choose the first map you want to use. This is called a basemap because it is the map on which the other data will be layered. You can select the location you want on a basemap. If necessary you can search for a location by entering its name, address or Eircode. You can also zoom in or out using the menu on the right hand side of the page. There are ten basemaps available, including aerial maps and historical maps from as far back as 1837. The most up to date basemap is called the GeoHive map and this is the one used in this lesson.

### True or False?

1. GeoHive allows the use of a maximum of two basemaps on the same display. false
2. The information provided by a GIS is based on geospatial data. true
3. The transparency function allows the GeoHive user to adjust the contrast of the different layers used. true
4. GeoHive provides three kinds of basemap. false
5. GeoHive does not provide a dataset showing population statistics. false
6. A map maker is called a cartographer. true
7. A GeoHive map cannot be shared with anyone. false
8. The dataset called ‘Transport’ is in the category called ‘Population and Economy’. true
9. The oldest map available on GeoHive is from around the 1940s. false
10. GeoHive offer four historic maps. true

### Glossary of terms

platform
an (offshore) oil platform is a large structure containing drilling machinery, storage, living quarters etc.; may be floating or attached to the sea-bed
cartography
the study of map making
aerial maps
photographs or images as seen from the air
basemap
the original map to which layers are added
data catalogue
the GoeHive catalog which displays the data set menu
data sets
groupings of related geospatial data
Eircode
an Irish post code system that uniquely identifies every building
GeoHive
an online platform to deliver geospatial information
geospatial reality
computer enhanced representation of geographic information
layered mapping
map display technique in which features of different types are assigned to layers that can be viewed separately