Redirect on a form submit

Redirect without querystring


$form_state['redirect'] = drupal_get_path_alias('taxonomy/term/' . $form_state['values]['region']));

Redirect with querystring


$form_state['redirect'] = array(
  drupal_get_path_alias('taxonomy/term/' . $form_state['values]['region']),
  array(
    'query' => array(
      'ref' => 1
    )   
  )
);