Assertion: alteration's effect | /r/HasProperty | described for a number of catchments
Facets:
value: over the world
type: LOCATION
Source sentences:
text: Effects of dam construction on riparian zones are described for a number of catchments all over the world, but more comparative work is needed between catchments and over long time periods before the global implications of changes to riparian ecosystems are known (Nilsson and Berggren 2000).