$terms = wp_dropdown_categories(array(
        'taxonomy' => 'news-categories',
        'hierarchical' => 1,
        'show_option_none' => "CATEGORIES",
        'option_none_value' => "",
        'name' => 'news_cat_name',
        'id' => 'cat_search',
        'value_field' => 'slug',
        'selected' => 1,
         ));

$('#cat_search').change(function () {
    var dropdown = $('#cat_search');
    if ($(this).val()) {

        window.location = "<?php echo esc_url(home_url('/')); ?>news-categories/" + $(this).val();
    }
});