Change variable for query with dropdown menu

Hi all,

in this page: https://isonomia.uji.es/comunicados/

I use this code, to show the posts of the category “isonomia” in a year:

<?php
$year = date('Y');
$catquery = new WP_Query( "category_name=isonomia&year=$year" );
while($catquery->have_posts()) : $catquery->the_post();
?>
<?php the_time('Y-m-d'); ?> - <a href="<?php the_permalink() ?>" rel="bookmark"><?php the_title(); ?></a><br />
<?php endwhile; ?>

I want a dropdown menu in the footer to change the $year variable to show other year posts with the category “isonomia”. Is it possible?

I don’t want to use the wp_get_archieves because it shows with a other template… I only find likely solutions with forms POST GET

Thanks for your replies.