The University of St Andrews currently have three open positions for PhD scholarships in spatial analysis and quantitative human geography. These positions are open to both UK and international students and candidates can propose project that are related to the Connecting Generations project. I am personally involved in "Connecting Generations across Geography" topic, where we plan to use network analysis and human mobility modelling to study spatial patterns of adult children and their parents.
Other eligible topics can be found here:
More info on the application.