The Atlas of Water. Maggie BlackЧитать онлайн книгу.

      Water means life – a truism so often repeated that its significance becomes lost. This vital natural resource – falling from the sky, bubbling up into springs and lakes, flowing in streams and rivers – is so fundamental to human activity that everyone must have access to it. Leaving aside questions of unequal power over resources, the very nature of water militates against this. Rain may fall equally “on the just and on the unjust fellow”, but everything depends on where they are standing. There is nothing “just” about annual rainfall distribution, which varies from a few millimetres in some places to thousands in others. And as the climate comes under increasing pressure, the meteorological patterns that scientists have worked for generations to understand are becoming even less predictable. Rainfall, which regenerates all other surface and underground sources, may be about to become even more unjust than before. Rain’s erratic choice of landing place, from deserts to forests, tropical to temperate zones, mountains to valleys, is not the end of this complicated story. Unlike other elements on which life depends, it frequently changes its state – from liquid to vapour, from liquid to ice, and vice versa, depending on the season. Water in lakes and reservoirs is constantly evaporating. And water in the landscape never stands still – it is always on the move. It seeps into the soil for use by plants and creatures, or percolates into aquifers where it renews underground supplies. It travels downhill on even the slightest of gradients. Navigating around whatever impediments it finds in its way, surface water enters a complex system of streams and tributaries, joining an ever larger flow destined for the sea. Many of these linked river networks are occupied by different peoples, states and jurisdictions. At any and every stage along its journey, water is used – and sometimes re-used several times – to support life and economic activity. Maximizing its potential for different uses and environments requires technology, investment, control of pollution, regulation, and efficient service delivery. Take just one example. Rain falling on the Tibetan Plateau finds its way into China’s Lancang river. At many stages downstream, flow is diverted by hydraulic construction and human ingenuity into paddy fields to grow rice. Elsewhere, the speeding stream generates electricity when channelled through hydropower turbines. Towns and cities remove water for human consumption and industry, and discharge wastewater back into it. As the river slows and broadens in its lower reaches, becoming the Mekong, it supports a vast aquatic environment on which local fisherman and wildlife depend. Eventually, it enters the South China Sea, having passed through six countries and been endlessly manipulated and exploited along the way. Heightened demand In an ever more crowded world, the processes involved in this manipulation and exploitation – repeated in countless river basins large and small – are becoming increasingly complex. Much more is being demanded of hard-pressed resources. Rivers are increasingly fragmented by dams. Upstream users reduce both the volume and the

      Introduction

      quality of water descending downstream. Non-renewable supplies, in the form of fossil-water aquifers formed millennia ago, are becoming rapidly exhausted. Every drop of available supply has to be harnessed to agricultural, industrial or domestic use – and sometimes all three in sequence. The volume of renewable supplies remains constant and is unlikely to falter, despite the many meteorological fluctuations associated with global warming. But the pressures exerted on this finite supply, both from increased population, and from the increasing number of people expecting to enjoy an industrialized lifestyle, are profound. Competition between different types of use, and between upstream and downstream users, is becoming more acute. The extraordinary nature of the substance compounds the many difficulties of managing water in such a way that all these conflicting interests are adjudicated fairly. Awareness of the critical limits on freshwater supplies has been growing over the past 20 years, alongside more profound appreciation of environmental constraints. Indeed, the circulation of water in the environment – to preserve wetlands, conserve biodiversity, and protect climate stability – has itself become recognized as a category of “water use” necessary to nurture the planet and its other life-giving resources. One strategy for water conservation has been to attach an economic value to all its uses and apply market instruments, such as water-pricing, to prevent profligate extraction and consumption. But the treatment of water as a commodity like any other, to be traded and used for corporate profit-making, has caused huge resentment. In those societies where poverty is acute, and rural farmers and urban dwellers are surviving at levels close to subsistence, unsubsidized water services effectively mean no water services at all. However important it is to conserve supplies, the story of water will be even more unjust if the least well-off bear a disproportionate burden of the costs. In fact, the problem of water as it relates to people in non-industrial environments is that most of them use too little water, rather than too much. Around 700 million people are still without a reliable source of drinking water, and 2.4 billion people are without basic sanitation. Having no tap at home constrains water use to the point where lack of personal hygiene is at least as much of a disease risk as lack of safe drinking water. Any attempt to improve water management in such a way as to make distribution more just should spread services to those with no protected water supply, many of whom currently spend much more on water purchased by the litre and carried home in a pot, than those living where pipes and taps are prolific. With water, as with pressure on other natural resources, it is not the poor who are pumping up industrial-scale quantities to sell as a marketized commodity, or to irrigate sugar or cotton plantations in unsuitable dryland environments. Nor are they manufacturing or buying televisions, computers, cars or other sophisticated consumer products. It is not the disadvantaged and underfed who are polluting rivers with pesticide residues and chemical wastes, or eating farmed fish or hamburgers requiring large quantities of water for their production. The industrial lifestyle is propped up by water even more than it is propped up by oil.

      10

      Water profligacy Food is one of the most thirsty water consumers. Over 70 percent of water withdrawals are used for agriculture, to irrigate fields or spray crops. But much of this water fails to reach its target – the roots of the plants; it is lost to the atmosphere, or returned to the water system unused. If poorly managed, channel irrigation can actually damage the soil, leaving it saline and unproductive. For this and many other reasons, including the social disruption and environmental damage caused by large dams, it is generally acknowledged that the train of “progress”, in which large-scale irrigation projects opened up new agricultural land for cultivation, has run into the buffers. Despite the uneven distribution of land ownership and cheap food, since the expansion of food production that accompanied the Green Revolution it has been possible to envisage a time when no child would go to bed hungry. But over 780 million people are still without a sufficient or nutritious diet, and making a serious dent in the hunger figures is becoming increasingly difficult. If food production is to keep pace with increasing population, and prices are to be kept in check, water efficiency in agriculture will have to be given far more attention. Volumes available for agriculture are likely to decline or remain static as industry and expanding urban centres increase their share. Technology will have to be harnessed to reducing water wastefulness. Up to now, hybrid seeds have mostly required extra water for cultivation; more attention will have to be focused on plant strains that require less