Does HR professionals have job opportunities in Dubai? does localization have affect on HR?

Yes, Expats have opportunities everywhere in Dubai in any given industry and position BUT localization is also prominent. It is stated on the labor law that if a local is found to be competent and qualified enough to assume your position, then you don't have any choice but to give way to the locals. And who would do well on an HR job position that requires you to know so much about the rules in your country??...Locals 

It may be stated on the law but don't worry, just do well on your job and your company won't let you go and job security in Dubai is nothing to worry about. Locals here are good to expats and we work hand-in-hand together in making this country a better place for everyone.

Localization has caused many foreigners to lose their respected jobs. I'm seeing this effect in KSA especially.

Yes it is. For as long as you fit with the qualifications requirement of an HR or better yet you excel with the requirement, well, the job is for you. Competition in Dubai and the rest of the world is really, so its really into us, who will stand out. Of course, organizations want qualified, expert employees - it is for business efficiency .. company do not want to teach anymore thats' why they are hiring more compentend people that the others. BUT, it depends with the positions you are applying for ...