this pattern, but the basic principles are the same. Weandering rivers exhibit 

 a general tendency to migrate downvalley by eroding the cut bank on the out- 

 side of a bend from a point roughly midway through the bend and extending 

 generally to the beginning of the inside of the next bend downstream. The 

 gradual downvalley progression of the bends usually remains within a zone 

 called the meander belt drawn near the outside of each meander. The width of 

 the meander belt is usually constant for regular meander patterns. Irregular 

 meander patterns do not necessarily maintain a constant meander belt width, 

 but the erosion at the outside of bends is typical. The difference between a 

 regular meander pattern and an irregular meander pattern and the expected 

 zones of erosion associated with each is shown in Figure A-8. It is apparent 



Regular Meander Pattern 



Irregular Meander Pattern 



Figure A-8. Schematics of regular and irregular meander patterns and 

 typical erosion zones. 



93 



