The Select data by topic pop-up lists all of the EnviroAtlas Data theme topics as well as four geographic extents.

---

Select by theme

To limit the availability of data layers by theme, click on the theme name. Multiple themes may be selected and appear in bold text. This results in a reduced list of themes (and associated data layers) displayed in the left-side column.

---

Select by National or Community

To show only highly-detailed EnviroAtlas community data layers in the left-side column, click the EnviroAtlas Communities checkbox. Data themes that have no community layers show as greyed-out. The list of themes in the left-side column reduces accordingly. Likewise, to limit the selection to only national data layers, click the National checkbox to make only National extent layers available.

---

Select by geography

You may limit the availability of EnviroAtlas community data layers by geography. Click one of the Geography buttons at the bottom of the pop-up and the list of themes in the left-side column are reduced to only themes and layers that contain data layers for the selected geography.

---

Clear all topics

Click the clear all topics checkbox in the top bar to restore the full data theme list.