I'm working on a network project and I've hit a wall with DHCP scopes in server 2008r2. My network topology is as shown:

the "service server" contains the Active directory, DNS and DHCP services amongst others. Now the clients are split into vlans which obviously means that they are on different subnets. The ip addressing scheme is 172.16.0.0/26
how do I go about setting DHCP scopes whereby there clients are given IPs based on their vlan number?