Debris Torrent Deluge of water charged with soil, rock and organic debris down a steep stream channel. Dec iduous A woody plant having leaves which die and fall away from the stem. Habitat Any open water area in which the mean water depth exceeds 6.6 feet at mean low water in nontidal and freshwater tidal areas, or is below extreme low water at spring tides in salt and brackish tidal areas, or the maximum depth of emerging vegetation, whichever is greater. Deg radation 1. Erosional removal of materials from one place to another.
Degradation lowers the elevation of streambeds and flood plains.
Downgrading of a streambed by scour. The elevation of the streambed is dropping and, usually, the banks are eroding. A wetland which has been altered by man through impairment of some physical property and in which the alteration has resulted in a reduction of biological complexity in terms of species diversity of wetland-associated species which previously existed in the wetland areas. Del ta 1. Silt deposits, generally triangular in shape, collected at or in a river's mouth.