I created terrain in RAS mapper in HEC- RAS Mapper but the created terrain contains errors. At full plot it shows rectangles while when I zoom IN then its shows closed spaced lines. This issues is only related with WorldDEM 12 m resolution. Otherwise model works fine with Glabal DEM i.e. SRTM, ASTER, and ALOS World3D.
Finally, I have been able to figure out the reason for DEM with line issue in RAS Mapper. The reason was the different Geoid i.e. EMG 2008 in case of WorldDEM. So I converted it to the WGS84 Ellipsoidal Reference.