GeoGraph - photograph every grid square

This particular stretch of mudflats drains inland, with a rather straight channel carrying the water back to the river. I'm not sure of the explanation for this natural phenomenon, but I suspect it might be that when the river floods, it deposits the largest load of silt at the point closest to where it bursts its banks. (This is certainly the reason why levees form along rivers prone to flooding.) The sun can be seen setting behind the Forest of Dean.