URL redirect for changed url structure
You can use Path Redirect module. Module page says -


  This module allows you to specify a redirect from one path to another
  path or an external URL, using any HTTP redirect status.


As I see you are talking about taxonomy terms, so alternatively you can use Taxonomy Redirect.


  This module allows the administrator to change the destination of
  Taxonomy Term links.
  
  
  The module can now handle redirections at the term level.
  You can specify a replacement character for spaces and + characters.
  You can specify a list of characters or strings to remove from the path
  You can enter php code that will create your path at runtime (In 5.x-1.3, variables for term ID ($tid) and term name ($tname) are available to use in your php code).