The Ottawa River is a fairly fast moving river and has a number of rapids along its length. Rapids create turbulence in the water and as a result, change the way the river reflects light (lightens the tone). You can determine in which direction the river is flowing by looking for an abrupt line at the start of the rapids and a less-distinct end of the rapids. Two sets of rapids are visible in the enlargement shown here. One set (B) is just east of the only bridge in this image and the other is further down river at A. A number of parks, very characteristic of the city of Ottawa, are visible in brown and green shades along the river edge (C). The commercial versus residential neighbourhoods are very distinct in this image.