On an ordinary day, apporoximately 15 "incidents" are reported to the authorities in this breakaway colony of Britain.

A car hits a land mine. A truck is shot up in an ambush. A farmer's home is burned. A section of rail line is sabotaged. A progovernment "sellout" is beaten or killed in his village. A half-dozen Patriotic Front guerrilla and "collaborators" are tracked down and shot. Occasionally a bomb explodes in a department store. Now and then a mortar or rocket round is fired at a troop encampment or a tribal village or a suburban home.

This is called war in Zimbabwe-Rhodesia.

Great armies do not clash by day or night. There is no combat in the air. The cities are not under siege. Bombs have been dropped inside the country by government forces only twice in the last two years. There is no "front." The violence is random and it may occur anywhere.

Robert Mugabe, the political commander of a guerrilla army, has designated 1979 as "the year of the storm," a year of escalation in the fighting. He has, by government estimated, 11,500 men in the countryside, armed with a variety of small arms and automatic weapons, principally the AK47 of Soviet, Chinese and Eastern European origin. They have mortars and recoilless rocket launchers and rifle grenades and land mines of every description.

But in the classic terms of warfare, there has been no escalation. The guerrilla army has occupied no territory, constructed no installations or base camps and mounted no large operations. There are only the "incidents."

The other guerilla army inside the country is led by Joshua Nkomo from his headquarters in Lusaka, Zambia. He has, by government estimate, 3,500 men in the field, armed with the same sort of weapons as Mugabe's. Their tactics are the same: "incidents."

So the "war" goes drip, drip, drip. It is frustrating to the government troops because they so seldom find anyone to fight.

It is frustrating to the civilian population because the risks are constant and so random.

Zimbabwe-Rhodesia is half the size of Texas. It contains 7 million blacks and 200,000 whites. They have responded to the guerrilas in ways reminiscent of the American Indian wars of the 19th century. Their "wagon trains" are armed convoys. Their farms are fortified. They employ professional gunslingers and there are even bounty hunters, said to be paid $1,500 a head. I met one here, a bearded, heavy-set young man, guzzling beer before heading off into the bush with an automatic rifle, grenades and a load of ammunition.

Every farming area has its own civilian "sticks" or posses to provide mutual protection and cull out the guerrillas. So do many of the urban neighborhoods. The whole country is a gun-lover's paradise. Men and women of all ages and color are armed. A young woman got out of a car loaded with children the other day. She was carrying a locally produced version of the Uzi submachine gun. Her automobile had been reinforced with steel plate to protect it against land mines.

There are check-in counters for firearms in hotels, office buildings and airports. But some people wear weapons constantly. At a farm outside Bulawayo a few days ago, I had lunch with two families. The men never took off their pistols. One of the little boys had a toy pistol in a holster. Peter Charsley, the host, laughed and said: "It's as much a part of my costume as my pants."

That is the civilian response to the "war": universal self-defense.

The military forces of the Salisbury government have a broader stategy. Their first task is to protect "vital assets," which include the industrial, commercial and agricultural capacities of the country, the rail lines, highways and military installations. Their second task is to prevent the "subversion" of population by the guerrillas. Their third task is to "cull," "waste," "zap," "pull," "slot," "take out," "stonk," "drop" and "sort out" -- to kill, in short -- the guerrillas, who are known to the troops as "sooks," "cts," or "Charlie Tangoes" (for communist terrorists), "terrs," "floppies," "munts" and "houts."

For these tasks they have assembled a mixed force of approximately 75,000 men and women. They include a military force of about 22,000 regulars, draftees and reservists, 8,000 paramilitary members of the British South African police, 35,000 police reserves, and about 10,000 auxiliaries and guards. Of the total, roughly 80 percent are black.

The older people in the force -- many in their forties, fifties and sixties -- are used in static defense tasks. They guard "vital assets," run rail and highway convoys, man road blocks, operate communications facilities and provide security in urban and rural areas.

The guard and auxiliary forces -- all black -- are assigned primarily to the villages in the tribal trust lands.

The regulars go out "culling." They engage in search-and-destroy sweeps. They run intelligence networks. They lie out in the bush in observation posts.

They set up ambushes, plant land mines, disrupt the infiltration routes out of Mozambique on the southern border and out of Zambia to the north.

Their "killing machine" is "the fire force," quick-reaction troops who attack guerrilla concentrations with paratroops and infantry operating out of helicopters and Dakota transports. They use gunships and close air support and trackers who have successfully followed a spoor for as much as 30 miles.

Their fondest missions are the "externals," the raids into Mozambique and Zambia in search of guerrilla camps and the materials of war. They bomb and strafe and put their troops on the ground to "hammer" and "stonk." How often these externals are run is not announced but the military commander, Gen. Peter Walls, has said that not a day goes by without operations outside the country.

The government says this year's body count is 2,717 confirmed kills, 5,162 presumed kills and 5,000 seriously wounded guerrillas. The government's losses, by its own count, have been 256 dead and about 700 wounded.

Yet, there are more guerrillas in the country today than a year ago and the infiltration flow keeps building.