SQL Server 2012 :: How To Create Staging Table To Handle Incremental Load

We are designing a Staging layer to handle incremental load. I want to start with a simple scenario to design the staging.

In the source database There are two tables ex, tbl_Department, tbl_Employee. Both this table is loading a single table at destination database ex, tbl_EmployeRecord.

The query which is loading tbl_EmployeRecord is, SELECT EMPID,EMPNAME,DEPTNAME FROM tbl_Department D INNER JOIN tbl_Employee E ON D.DEPARTMENTID=E.DEPARTMENTID.

Now, we need to identify incremental load in tbl_Department, tbl_Employee and store it in staging and load only the incremental load to the destination.

The columns of the tables are,

tbl_Department : DEPARTMENTID,DEPTNAME

tbl_Employee : EMPID,EMPNAME,DEPARTMENTID

tbl_EmployeRecord : EMPID,EMPNAME,DEPTNAME

How to design the staging for this to handle Insert, Update and Delete.