From Halopedia, the Halo wiki
Hemorrhage is a map variant of Forge World. It is a remake of Blood Gulch from Halo: Combat Evolved with specific elements from Halo 2's Coagulation built into the Canyon. Specifically, the bases are ported from Blood Gulch, while the terrain geometry is a direct port from Halo 2's Coagulation, scaled to match Halo: Reach.
Weapons and vehicles
The bases feature a Wraith, a Type-32 Ghost, two Warthogs, two Mongooses colored with the base they belong to, and a Rizvum-pattern Revenant. A Plasma Repeater, a Magnum, and a Plasma Pistol are the weapons found inside. A DMR, a Needler Rifle, and a Sniper Rifle are at the top with a health pack. A Shotgun spawns outside the bases, in a pile of rocks. A concussion rifle is located along the edges of the cliffs. A Kopasa'mada-pattern plasma launcher replaces the Rocket Launcher from previous games and is found in the rocks of the center.
One would commonly see a Warthog with a gunner circle their enemies' base. This can prove to be rather effective, as players wont be able to leave their base. However, they can stop the Warthog if throwing a precisely thrown grenade at the right time, hopefully flipping the truck, and exposing the occupants to the enemy team.
Also common, when starting a match, whoever gets to drive the Wraith will often "bombard" the enemy team's base or Wraith spawn. However, this is a rather noneffective tactic, as the shots often fall short, doing nothing. Unless a Warthog decides to "dig in" behind a hill, this is not really an effective idea.
Many players will often camp with Shotguns by the teleporters, to stop their enemies from using them.
Sniper Rifles can be used to counter vehicles from getting to close to your base. If you can't destroy an enemy vehicle, try to damage it, it'll make it that much weaker and easier to destroy.