Middle-aged and as parched with acedia as the most tropically withered Graham Greene hero, Dr. Mallory runs a health station in an impoverished corner of Africa and drills for water beside a dry lake.He has no patients, the population having fled because of fighting between government troops and nomad guerrillas from the desert northern province. His drilling is fruitless, and he risks execution by Harare, the guerrilla leader, who resents his search for water and his dream of a green Sahara. "The southern advance of the desert was Harare's greatest ally."

Mallory is about to leave - Captain Kadwa, the devious leader of the government forces, also wants him out - when a bulldozer uproots a tree stump near the airstrip and water begins to flow from the cavity. Soon, it is a stream 10 feet wide; after a while, it has become a mighty river 900 feet cross and 24 feet deep, filling the lake and utterly transforming the landscape.

That is the setting and start of J.G. Ballard's complex parable, "The Day of Creation." It pits Mallory the Creator - he regards himself as the father of his river and names it after himself - against his creation. And in a wider sense, it raises the paradox of human endeavor turning against its own sources and poisoning them; books that strip forests, irrigated deserts that fill up with shanty towns, junked cars, beer cans and war.

Even before the Mallory amounts to anything, Mallory finds that others expect to move in on it. He is furious when he sees one person filling a water bottle, and another, a soup ladle. While it is still only a stream, he pays Capt. Kadwa a thousand dollars for rights; but once it is a river, Kadwa decides to use it as the centerpiece of an independent state that he will be in charge of.

It is a good parable, but the book has some painful defects. Ballard loads it up with a number of auxiliary characters, each of whom stands for something but does not do much more than that.

There is Sanger, a charity hustler who hopes to prosper by getting himself televised distributing food. Everyone in the area has fled, so there is no one left to give food to. He turns, instead, to filming Mallory's quest; the result is a murky, overextended sub-parable involving the usurpation of reality by the media.

There is Nora Warrender, who takes a boatload of wartime rape victims upriver, tangles repeatedly with Mallory, shoots stray soldiers, and dreams of establishing a realm of women and animals somewhere in the hinterland.

Mallory also suffers from insubstantiality.

The same defect occurs with Ballard's Africa. Although there is a great deal of vivid description, we never seem to get a particular sense of a place - as we do with Greene - nor even of the mood and menace of a place - as with Joseph Conrad.