point bars and have less tendency for downvalley shifting. The channels 

 are more stable with respect to lateral shifting. 



sinuousity — A measure of the amount of winding of a river within its flood- 

 plain; expressed as a ratio of the river channel length to the corres- 

 ponding valley length. 



slope — The inclination or gradient from the horizontal of a line or sur- 

 face. The degree of inclination is usually expressed as a ratio, such 

 as 1:25, indicating one unit rise in 25 units of horizontal distance, 



2 



small river - A river with a drainage area less than 100 km and a mean 



annual flow channel top width of less than 15 m. 



split river — A river having numerous islands dividing the flow into two 

 channels. The islands and banks are usually heavily vegetated and 

 stable. The channels tend to be narrower and deeper and the floodplain 

 narrower than for a braided system. 



stage — The elevation of a water surface above or below an established 

 datum or reference. 



standing crop — The abundance or total weight of organisms existing in an 

 area at a given time. 



straight river — The thalweg of a straight river typically winds back and 

 forth within the channel. Gravel bars form opposite where the thalweg 

 approaches the side of the channel. These gravel bars may not be ex- 

 posed during low flow. Banks of straight systems typically are stable 

 and floodplains are usually narrow. These river systems are considered 

 to be an unusual configuration in transition to some other configura- 

 tion, 



subarctic — The boreal forest region. 



167 



