This site uses a variety of Open Authentication providers to enable you to log in. At the moment, the supported providers are:
Provided you still have access to the email address that you used when uploading photos in the past, you can link that to your new login account. That will give you the ability to edit or delete older photos. You can link as many email addresses as you want, provided that you have the ability to receive email at them. You can also link the same email address to multiple logins, so if you have, say, both Facebok and Twitter accounts and you want to be able to use both of them to administer your photos on this site, you can.
You can link your email address to your account at your profile page.
On the photo pages of individual buildings, photos that you have uploaded are marked with the user icon. You'll only see this if you're logged in, obviously.
You can find a list of all the buildings that you have contributed photos to on your photo list page.
Your profile page also shows photos that you have uploaded but that have not yet been approved by the site administrators.