Hydrology

Hydrology is divided into three layers; lines, polygons and points. The hydrology data is mostly taken of the films of the DMA and AMS map sheets but aerial photos and SPOT-5 satellite images were used when updating the coastline along urban areas.

The outlines of Snæfellsjökull glacier have also been updated. Some new lakes have been added using SPOT-5 satellite images. The line and polygon layers show glaciers, lakes, rivers and ditches. Islands and skerries are also in these layers. Names have been connected to most features; in the polygon layer around 2700 features are connected to names, the line layer contains around 42,300 features connected to names and the point layer contains around 260 features that are connected to names. The point layer shows the predominant waterfalls, hot springs and rapids. In the point layer there are also points that show where rivers disappear under the surface.