They occurred also in the adjacent spiny bush with distances to the nearest watercourse up to 260 m at Ambatoabo, 90 m at Ankoba, 680 m at Mangatsiaka, 130 m at Tsimelahy and 460 m at Ebosika.
If released into watercourses it builds up in fish and organisms that feed on them.
Seepages may occur in the walls of canyons and pools may survive in deep shade near the dried up watercourse below.
The tide of summer bungalows creeps up their watercourses.
Being set up along watercourses, GFMs may spontaneously form a coherent network of corridors in agricultural landscapes.
The increased production and wide applications of nanoparticles are making it more likely that such materials will end up in watercourses, either as medical or industrial waste, or when used as ecological tools with unknown consequences for aquatic life.
Much is washed off by rain, ending up in local watercourses where dissolved nutrients can cause algal blooms and kill fish.
Watercourses regularly switch about: as one waterfall dries up, another roaring cataract will spring up unannounced nearby, like a burst water main.
Emergency teams are continuing work on shoring up flood defences, clearing blocked watercourses and drains and using pumps to keep water levels down.
An old canal showed up as a straight blue watercourse overhung with trees, while the Clyde looped through an old industrial quarter that has been remodelled for pleasure.
