Why Streams Meander

A number of theories have appeared in the literature to explain why streams meander. They are. for the most part. the outgrowth of field studies by geologists and geographers. who had not the facilities to isolate the variables of flow. such as velocity. volume. slope. load. angle of attack against the banks and type of rock through which any given stream meandered. It 1s not surprising that the opinions of these men were so divergent or that they were correct only under certain circumstances. Men sent in reports of streams that meandered only after attaining some size. whereas others meandered from their very inception. There were meandering streams that degraded their channels. those that aggraded them. and still others that did neither. It seemed that no matter what the circumstances were streams meandered. However. some did not meander and some, once having produced meanders. set about trying to eliminate them (Matthes, 1948). Streams meander as intricately in salt-water swamps as in freshwater ones. Goldthwait (1987) studied the meanders ot streams subject to Udal action. Cockfield (1921) took note of the meanders of streams flowing in perennially frozen ground where debris froze to the channel bottom unless it was removed as soon as it accumulated. Geologists saw other streams that produced their curving loops in an area floored by gravel, muck. sand, volcanic ash and ground ice (Cockfield, 1921), in glaclal (Bostock. 1986) and in auriferous gravels (Spurr. 1898). They