Hydrology: Attributes of a Healthy Stream
An alluvial stream is one whose channel is composed of the sediments transported by the stream itself and that generally changes the shape of its bed as the rate of flow changes. (Adapted from Attributes of an alluvial river and their relation to water policy and management by Trash, McBain, and Leopold).
Attribute Three (Part B): The Stream Channel is Free to Migrate
As streams migrate, the channel erodes older floodplain deposits on the outside bend and deposits sediments on the bar on the inside bend.
Channel migration is one of the most important processes creating habitats for plants and animals, including fish and aquatic insects. That the stream has occupied numerous locations in its valley is evidenced by direct observations of its movement over time, and by looking at aerial photos where old meanders are often clearly evident.
Typically, channels do not migrate during periods of low flow. Rather they move across the floodplain when flows approach and exceed bankfull discharge.
Click on the image to see how, over time (decades and centuries), streams migrate across their floodplain.
Hydrology: Attributes of a Healthy Stream
An alluvial stream is one whose channel is composed of the sediments transported by the stream itself and that generally changes the shape of its bed as the rate of flow changes. (Adapted from Attributes of an alluvial river and their relation to water policy and management by Trash, McBain, and Leopold).
Attribute Three (Part B): The Stream Channel is Free to Migrate
As streams migrate, the channel erodes older floodplain deposits on the outside bend and deposits sediments on the bar on the inside bend.
Channel migration is one of the most important processes creating habitats for plants and animals, including fish and aquatic insects. That the stream has occupied numerous locations in its valley is evidenced by direct observations of its movement over time, and by looking at aerial photos where old meanders are often clearly evident.
Typically, channels do not migrate during periods of low flow. Rather they move across the floodplain when flows approach and exceed bankfull discharge.
Click on the image to see how, over time (decades and centuries), streams migrate across their floodplain.
Hydrology: Attributes of a Healthy Stream
An alluvial stream is one whose channel is composed of the sediments transported by the stream itself and that generally changes the shape of its bed as the rate of flow changes. (Adapted from Attributes of an alluvial river and their relation to water policy and management by Trash, McBain, and Leopold).
Attribute Three (Part B): The Stream Channel is Free to Migrate
As streams migrate, the channel erodes older floodplain deposits on the outside bend and deposits sediments on the bar on the inside bend.
Channel migration is one of the most important processes creating habitats for plants and animals, including fish and aquatic insects. That the stream has occupied numerous locations in its valley is evidenced by direct observations of its movement over time, and by looking at aerial photos where old meanders are often clearly evident.
Typically, channels do not migrate during periods of low flow. Rather they move across the floodplain when flows approach and exceed bankfull discharge.
Click on the image to see how, over time (decades and centuries), streams migrate across their floodplain.