Asking Questions: Querying Data

Arc Explorer Java can help with easy questions like

  • What data is in that polygon/s?
  • Who owns this land?
  • What is the land use?
  • What is in my circle/square/polygon of interest?
  • What is in this 100m buffer zone around a proposed development?

First off note the selection icons in the top menu.

If the layer has attributes that can be queried, then these buttons will be active (as opposed to greyed out).

What do the buttons do?  The info button – useful for pointing and clicking – just make sure you are querying the correct layer.  If you don’t see the info button or you get the wrong answer, check the correct layer is selected.

search

Find – will search an active layer (case-sensitive); highlight the result and the pan or zoom to your selection.

Map tips – handy if you want hide the labels but hover and get some site details

Clear Selection – does just that

Selection tool – allows selections by rectangle, line or polygon

Buffer – creates cool buffers around a selection, though these cannot be saved

Attributes – are the contents of data fields of the layer

Working with Arc GIS Layers

Layer Properties exposes powerful features of Arc Explorer.

From here you can:

  • change colour fills and styles of your polygons
  • line colours and styles
  • add labels
  • create automatic keys based on any selected field
  • make layers appear and disappear above / below certain scales (NB easy to lose layers, so take care)

When experimenting with changes always use the APPLY button first, especially if you are changing scale appearance/disappearance