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Last December's climate conference in Kyoto offered little hope for the survival of the world's river deltas. These low-lying mudflats, paddy fields and islands at the mouths of the world's great rivers are among the most fertile and densely populated rural areas on earth. They are also among the most vulnerable to the rising tides that are following stealthily in the wake of global warming. So Daniel Schwartz got there just in time.

His book, Delta, is a delight. It is first and foremost a picture book of the deltas of south and southeast Asia: a large-format album of black-and-white images assembled by the young Swiss photographer during five years travelling in the region. It is about life and death and the constant struggle for survival against a constant backdrop of water, the life-force of the five deltaic regions he visited.

But Delta is much more than an album. It is a rich exercise in photoreportage. The kind that Sunday supplements used to do before they gave up sending photographers round the world for anything other than fashion shoots and holiday snaps. Schwartz's serious purpose is revealed in the subtitle: The Perils, Profits and Politics of Water in South and Southeast Asia. Here, in the extended picture captions and extracts from other people's journalism and academic study, is a strikingly original patchwork of information. As the pictures reveal the human population of the deltas, the text unpicks the forces that shape and buffet their lives.

At the book's heart is the plight of the millions of landless Bengalis who occupy the shifting islands of the joint delta of the Rivers Ganges and Brahmaputra, which occupies southern Bangladesh and a wedge of eastern India, including Calcutta and Dhaka. The vast cascade of water from two of the world's largest rivers, which drain much of the Himalayas, has no permanent path to the ocean. It has a myriad shifting channels, some as wide as the English Channel, which constantly make and break islands on which the flotsam of two of the poorest nations on earth contrive to live.

Catastrophes are frequent. Sometimes the rivers flood more than usual - covering up to half the country in a sheen of water. Sometimes it is the sea that invades. In 1991, a cyclone swept through the delta at more than 200 kilometres per hour (multiply Britain's 1987 hurricane by two, and imagine it blitzing the population of London - all camped out on something like the Dogger Bank), bringing a wall of water with it. The final death toll was put at 130,000, plus or minus a few tens of thousands. It is as if Reading disappeared with no survivors. Life is that cheap on the delta. They do not even count the dead.

After you have contemplated the numbers, switch back to the images of eroded sandbanks, dismembered villages and disintegrating lives grabbed by Schwartz, visiting in the aftermath. For all the horror, his pictures are never intrusive and never mawkish, but he is always up close with his wide-angle lens.

Then hit his captions: "Snakes, like the people, flee to the roofs; if there are too many deaths from snake-bites, people seek refuge on the dams, but are often driven away by the authorities. In the meantime, gangs in boats loot the abandoned houses..."

And lesser tragedies happen all the time. When I visited the region in 1992, a quiet year, the Brahmaputra one night devoured forever ten square kilometres of land, making 5,000 families homeless. Imagine the fuss such an event would cause in Britain. But in Bangladesh it made just two paragraphs in the national press. And the text reminds us that a fifth of Bangladesh could disappear in just such piecemeal manner within a century as sea levels rise.

Water is the pivot of this book. It is the delta waters of the Mekong that fed the empire of Angkor Wat and were meant to irrigate Pol Pot's "year zero", an intended agrarian paradise that turned into the killing fields. Water provides the training grounds of Burma's slave society and the rice basket of Vietnam. It provides the highways of Bangladesh, and harbours the man-eating tigers of the Sundarbans, the world's largest mangrove forest.

Water now fills the thousands of holes left by American bombs as they dropped Agent Orange on the forests and paddies of Cambodia. Now farmers are turning those holes into ponds for raising prawns - the newest boom crop of southeast Asia.

Schwartz provides a fusion of art, journalism and acerbic, academic inquiry that I found quite intoxicating. The images are cooler in Luna Leopold's Water, Rivers and Creeks. A distinguished academic at the University of California, Berkeley, and former chief hydrologist at the US Geological Survey, Leopold offers as succinct a treatise on the principles and practice of hydrology as you could imagine. There is nothing fancy here.

This is the kind of book that students yearn for, but seldom find. No long sentences, no unnecessary abstractions, no self-serving artifice, no show-off bibliography. If his point is best made by sourcing the Reuters news agency or the eco-campaigning International Rivers Network, rather than some peer-reviewed tome, Leopold makes a point of doing it, without apology or disparagement. And since he can satisfactorily explain the principles of hydro-geology with a pudding basin, a bag of sand and a jug of water, he does just that.

And if the going gets political, he does not back off. Who knows how many large dams in the American midwest have been helped towards completion by Leopold's work? But he is as factual and unaffected on the downside of dams as on everything else. He accepts without regret that the days of dam-building in the USA are effectively over.

Can hydrologists say whether a dam is good or bad? Many would try. And Leopold's summary of the pros and cons of one of the most difficult cases, the Aswan dam on the River Nile, is masterfully brief and to the point. But he sees that ultimately many of the answers do not lie in hydrology at all. He gives his readers the science, but will not give the answer when it is not his to give. The demands for rivers for recreation and fisheries are strong, he says. And, dammit, people just do not like the things.

"The damming of rivers tears at the fabric of a spiritual attachment humans have for rivers," he says. "In this regard dams are an affront to the feeling of close association that people have for free-flowing streams... These basic feelings of kinship to natural rivers must be taken seriously."

In some parts of the world, dams are not about either aesthetics or hydrology. They are about brute political power - or so we are often told. In the Middle East, talk of "water wars" has an immediacy not heard elsewhere. Most books on my shelves on the topic are by interested parties with their own agendas - mostly Israeli academics anxious to preach peace and reconciliation or journalists anxious to scare their readers.

But Greg Shapland's book, Rivers of Discord, is a small masterpiece of dispassionate analysis, commendably happy to puncture the bluster of the scaremongers.

Shapland is a civil servant at the Foreign and Commonwealth Office, where he has been in charge of research and analysis on both Middle East water issues and the Arab-Israeli peace process. His approach, as befits a mandarin, is cool and immensely thorough. He is as good on the hydrology as on the politics. If anything he is too keen to dampen expectation of war.

His overall assessment is that for all the discord, water wars, while possible, are unlikely. The tensions over international water resources - whether rivers such as the Nile, Jordan and Euphrates, or underground water reserves beneath the Sahara and the West Bank - should not lead governments to war, he says. Even in a region where water is in very short supply and political tensions are notorious. Wars, after all, are rather better at capturing land than flowing water. Rather, he says, governments "may be driven towards cooperation by a hard-headed assessment of their own self-interest".

Will water conflicts lead Israel to renewed war against its neighbours? The desire for control over the flow from the River Jordan has frequently been given as a major reason for the 1967 Arab-Israel war. But Shapland points out that, unlike in 1967, there is today "a lack of any significant water resources within exploitable distance" of Israel's current de facto borders.

To capture the potentially valuable flows of the Yarmuk would most likely require the destruction of a large number of small dams in Syria. Much is made of the Golan Heights as the strategically vital headwaters of the River Jordan. Not so fast, says Shapland. There is not actually much water up there. Most of the water drunk by Israeli settlers on the Heights is actually pumped up to them from lower down the valley. "War between Israel and its Arab neighbours over water seems out of the question," he concludes.

Similarly on the Rivers Tigris and Euphrates, which both flow out of the Turkish highlands and through Iraq to the Gulf (in the case of the Euphrates also passing through Syria). Despite bellicose noises over the years from downstream, as Turkey has built dams in the Euphrates headwaters, Shapland concludes there is probably enough water to go round - particularly if the two downstream countries would pay a little more attention to using the water they have efficiently. Again he concludes there may be much sabre-rattling, but "armed conflict (over water) is unlikely to break out".

While discussion of possible water wars has generally concentrated on disputes over rivers, the more long-term hydrological threats to national self-interest may lie in groundwaters. Most underground water reserves in the region were created in past centuries, when rainfall was much greater. They are thus essentially fossil reserves, like oil fields only much more mobile. Water inside aquifers can, at least under some geological circumstances, travel long distances. Sink a well on one side of the border and you can easily deplete water reserves on the other side, not just for a year or a decade, but for centuries or millennia.

But out of sight is often out of mind. Hydrologists may be concerned, but the political potency is not there. Thus, Jordan seems strangely unconcerned at how much of its strategically vital Azraq aquifer is being drained by Syria. Likewise, though Egypt makes warlike noises whenever Ethiopia even tentatively thinks of damming the headwaters of the Blue Nile, its reaction to Gaddafi's giant Great Man-made River Project, which sucks fossil water from beneath the Libyan-Egyptian border, is decidedly muted.

Another cautiously forensic piece of work on water policy is Terence Kehoe's Cleaning Up the Great Lakes, which charts the emergence of federal environmental regulation in the US, through the case of pollution policy on the Great Lakes. It combines almost journalistic attention to detail in the political process with an academic analysis of the underlying trends.

The story sees regulation of pollution into the lakes pass from a discredited piecemeal locally organised system to a formal federal regulatory structure characterised by legal conflict. It begins with the lakes acting as a sewer for the great postwar industrial heartland of the USA, and where "the authority for regulating water pollution in each of the Great Lakes states rested in part-time boards". Kehoe calls this "cooperative pragmatism". At any rate, the end result was waterways on fire, whole coastlines closed to visitors on health grounds and huge lakes effectively dead.

From this chemical, biological and political cesspit emerged much of modern environmental thinking. First came Rachel Carson's ground-breaking Silent Spring, an expose that had much to say about the new synthetic compounds - highly toxic and persistent - flowing into the lakes. On its back came a mass of self-styled public-interest organisations, fighting the good fight to "save our lakes", and finally the "emergence of a new generation of public officials who embraced environmental values". From Cooperation to Confrontation is Kehoe's subtitle. But at least it worked.

Fred Pearce is author of The Dammed.