I'd like to place sections of articles into categories on Wikipedia. (for example, placing "Pollution in India#Water pollution" into the category "Water pollution in India") Is there any way to do this besides creating a redirect page for the article and then putting the redirect page in the category?
First, let me say that I don't think doing this is a good idea. Category description pages on Wikipedia shouldn't contain article text, that's not what they're for. If you want to do this, make sure there is a consensus to do it. For some more information, see Creating category pages.
If you're sure you want to do this, I think the only way (ignoring custom or some existing extension) is to use template transclusion. This can be done two ways:
If you know that you'll always want only this specific section, you can enclose it in
But if you want to transclude different sections of the same article to different categories, that won't work (unless you also added some