Lake (1)
| large freshwater lake |
| large saltwater lake |
River (2)
| major river |
Continuous ice sheet (3)
| continuous ice sheet |
River / lake basin (4)
| with underlying groundwater basin contained within the boundaries of river / lake basin |
| with underlying groundwater basin extending beyond the boundaries of river / lake basin |
| less important river / lake basin, partly underlain by groundwater basin |
Groundwater (5)
| in major groundwater basin |
| in complex hydrogeological structures |
| in local and shallow aquifers |
|