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Desertification and development in South-West
Asia: A historical perspective
I. Irrigation in South-West Asia
II. Pastoralism on the iranian plateau
The international development effort so far has been based on the injection of investment and the transfer of technology. The people affected, whether as target populations or by contingent processes, have (on the basis of the assumption that they conform with our ideals of rationality) been expected to adapt themselves both as individuals and as groups to the resulting new conditions, and to develop new ways of relating to each other- new structural forms that would facilitate the optimum operation of the new technology. Within this paradigm, few specific projects and fewer large situations can be claimed as unqualified successes. Local populations rarely respond as expected. A common reason has been that their motivation is embedded in an organizational or structural form that was an integral part of the traditional production system and is not adapted to or appropriate for the new technology. When they run into ecological problems as a result, they often suffer disapprobation as well as deprivation.
Analyses of ecological problems deriving from development projects have suggested that deterioration of the environment can have negative consequences for society and individuals alike; but although the economic costs of environmental problems can be estimated fairly reliably in terms of lost production, the social, cultural and psychological costs are difficult to quantify usefully. These non-economic costs generate rearrangements in the distribution of populations and in social groupings which affect future living standards and production levels in ways we cannot predict. The need to view the totality of behaviour, thought and ecology in a perspective geared to the priorities of ecological viability and public policy presents insurmountable problems.
The long-term relationship between trends in living standards and environmental perception, between perception and responsibility for resources, and between responsibility and ecological impact is difficult to demonstrate conclusively. In South-west Asia, however, the fact that the interrelation of ecological and social problems can be viewed in the perspective of ten or more millennia of human residence and food production makes such a study somewhat more promising than elsewhere. This chapter treats examples of two types of land use that have been historically important in Southwest Asia, with the limited aim of illustrating some of the points argued in chapter 2.
Desertification and development in South-West Asia: A historical perspective
Roughly one third of the land surface of the earth is generally classified as dry and is estimated to contain fourteen percent of the world's population (UNCOD 1977a: p. 6-10). The productivity of dry lands is generally low, but their extent is so vast that their total production is nevertheless significant. Most of the territory of Southwest Asia is composed of such dry lands. The dry lands of South-west Asia in Iran, Afghanistan, Pakistan and North-west India are particularly important in the development context, because as a whole they are more densely settled than other dry regions and because their present population has inherited environmental problems caused by the longest history of human settlement and food production. But apart from the large sums spent on engineering the control and delivery of river flow, dry lands generally - and particularly in South-west Asia have received relatively little investment so far. However, they have great potential for development, if only the environmental problems can be solved. Therefore solution of the environmental problems of development in Southwest Asia is not only of direct economic significance for some one hundred and fifty million people, but is likely to contain important lessons for other dryland regions.
Historically the most significant types of land use and food production in South-west Asia have been irrigated agriculture, which requires substantial investment and is an intensive form of land use; and pastoralism, which requires relatively little investment and is extensive. In some semi-arid areas they have been combined with dry farming. Although these basic types are technologically very different, they have been closely interrelated, socially and economically, for thousands of years. Most human communities, especially in dry lands, have made use of two or more technologies; or if they have specialised to the effective exclusion of a second technology they have interacted economically with other communities which exploited different resources. The development effort, however, with its pronounced emphasis on technology, has not only tended to separate the treatment of technology (traditional or modern) from consideration of its social context, but has also neglected the interdependence of different technologies from the point of view of local labour and domestic economies.
Historical evidence shows some significant declines in production from time to time during the last five thousand years, but the causes (which appear in most cases to have involved a combination of both human and natural factors) have not been reconstructed convincingly. The Harappan civilisation of the Indus valley, for example, which must have been dependent on irrigation, fades from the archaeological record in the middle of the second millennium BC. The Mesopotamian systems (in presentday Iraq and southwest Iran) have gone through several cycles of growth and decline. The decline of irrigated agriculture in the Helmand delta (now on the border of Iran and Afghanistan) coincided with political decline in the tenth century A.D. Most systems of this type in developing countries have been in decline during the period of European expansion and in some cases much longer.
The value of a historical perspective is that it exemplifies the range of possible adaptations to a particular set of natural conditions, and their ecological and other consequences. The historical development of irrigation in the Indus valley and of pastoralism on the Iranian plateau is discussed in appropriate places below, but before getting into that more detailed discussion it will be useful first to summarize here the history of these forms of land use in South-west Asia.
Environmental problems in development generally derive not from basic technologies such as types of irrigation or grazing, but from the scale of the productive activity in relation to the resource. Before the first attempt to develop irrigation in the Punjab in the middle of the last century, irrigation (which probably developed in its most primitive form not long after the domestication of plants and animals, some ten thousand years ago elsewhere in Southwest Asia) had already served as the basis of vast agricultural projects, and had had environmental effects which reduced productivity seriously. The best known example is from Mesopotamia (see Jakobsen and Adams 1958 and Oates and Oates 1976). This was probably the largest ancient (preindustrial) system. Like smaller systems on the Helmand (now Afghanistan-lran), the Indus (now Pakistan) and the Oxus (now the Soviet Republics of Turkmenistan and Uzbekistan in Central Asia), and in other parts of the world, it was generally restricted to flood plains and was seasonal, depending on the annual flooding of the river.
Perennial riverine irrigation, which requires storage and gradual release of the water through the period of minimum flow, is largely the introduction of the industrial age. Such irrigation has allowed major increases in area under cultivation and intensification of cropping but it also magnifies the adverse effects of irrigation: soil salinity and waterlogging develop faster and some of the effects are more difficult to reverse. Perennial irrigation as a means of increasing agricultural productivity is an invaluable technological advance, but indiscriminate application can lead in the long run to reduction in productivity through adverse environmental change. In order to maintain productivity in the long term labour, water flow, and cultivation must be coordinated with some precision.
The oldest form of river flow irrigation in the Punjab (known as sailaba or flood-water irrigation) simply uses overflow within active flood plains. This simple technology has been economically important since the eighth century AD, when the Arabs distinguished irrigated from nonirrigated land for tax purposes. It did not require largescale organization of labour and it was ecologically viable, since it flushed the land, preventing accumulation of salts and maintaining fertility by the deposit of silt.
The next stage was the construction of inundation canals. These canals greatly extended the area of cultivation at the expense of a significant increase in labour requirements. But they were vulnerable to floods and were less viable ecologically, since they included no provision for drainage and so caused the accumulation rather than flushing of salts and raised the water table. But it is important to note that these canals for the first time required large-scale organization of labour, and of water distribution. However, this requirement was not yet beyond the capabilities of the local communities. So far the technology did not require organization on a scale larger than the immediate community.
The next change was from inundation to perennial irrigation. It was a quantum change, the spread of which marks the contrast between the ancient and modern periods. The modern period is characterised by much higher investment and involvement in a much larger economic universe. Where the ancient system had already grown beyond the capability of private enterprise and depended on government investment, the modern system depends on investment which is beyond the means of many national economies and is supported by various forms of international investment. The enormous increase in investment needed for this increase in productivity would not have been feasible except for a similar increase in the potential market. The market was originally provided by the investors - the British. It carried the Punjab through the ecological transition in more senses than one. Both the physical map and the society of the Indus Valley was gradually and irreversibly transformed. The process makes one of the most interesting stories in human ecological history. There is room here for only a brief mention of some of the most significant landmarks (For a longer review see Michel 1967).
In the middle of the nineteenth century the first modern perennial irrigation engineering project was begun in one of the interfluves of the Punjab, in what is now Pakistan. Despite setbacks, the programme gradually grew to incorporate all the Punjab plains and was extended into Sind. The enormous increase in the injection of water into these basically desert areas soon began to cause environmental problems. But no one felt any need to attend to them: it was simpler and more profitable for the investors to extend the programme onto new land than to repair damaged land.
The Indus valley irrigation system soon became by any standards the largest integrated irrigation system in the world. it has been growing for 130 years, and although now divided between India and Pakistan it is still being extended in both countries (though now as two separate systems), and still has room for growth. But in the wake of its expansion, serious environmental problems appeared. By the middle of this century these problems were causing real anxiety. Correction of them has become the major task of development. Beginning in the 1950s, development planning focused on increasing output in the Punjab by alleviating the environmental problems that had arisen during the colonial period as a result of the application of industrial technology to irrigation. But the planning was typical of the period: it was single-mindedly techno-centric. It was based on the assumption that such ecological problems could be solved by technology, and therefore paid little or no attention to their social or cultural dimensions.
Although the history of pastoralism in South-west Asia appears totally different from that of irrigation, there are interesting comparisons to be made. The two forms of land use represent opposite extremes in terms of the density of population they support and the level of investment they require in arid areas, but they are equally dependent - though in different ways - on exogenous political and economic factors.
Perennial irrigated agriculture is the most intensive form of land use and its development demands high investment and offers high returns. The necessary investment, which is generally beyond the means of the individual cultivator, or even the cultivating community, is carried out at the will of an urban-based financing institution. Really large-scale irrigation engineering systems, both before and after the Industrial Revolution, have been government programmes. Hence the perennial debate, worked out in classic form in Oriental Despotism (Wittfogel 1957), concerning the intimacy of the relationship between forms of irrigation engineering and forms of government. (Unfortunately this early attempt to treat technology as a problem of organization had no impact on the development effort, presumably because it did not deal in sufficient detail with technology as understood in the applied sciences.) In this way large scale irrigation engineering, because it requires substantial capital investment, invariably brings the cultivator into close, though not necessarily happy, relations with a broader economic universe and with a bureaucracy, and might therefore be taken as the classic development situation.
Traditional pastoralism, on the other hand, requires minimal capital, and perhaps the major problem in pastoral development has been the integration of traditional forms of pastoralism into national economies. There is an important cultural aspect to this problem which has characteristically received less attention than the technological and economic aspects. It can be seen in the growing credibility gap between planners and pastoralists which leads to cultural discrimination and accusations of irrationality. The situation is complicated by the fact that many pastoral populations, especially in South-west Asia, are in origin overflows from settled agricultural populations, and generally pastoralists do not depend on other sectors of the population for investment. In any case, when the cities could not control the nomads, the nomads raided the cities, and the impact of this historical relationship is still evident in the general antipathy between governments, which want to control and administrate, and traditional pastoralists, who want to be free of external control.
Ecological history is of great importance for any assessment of traditional pastoralism. But it is extremely difficult to reconstruct it in sufficiently reliable detail. Very little is known of the history of the vegetation on which pastoralism has depended over recent millennia, let alone since the earliest times. However, in South-west Asia there is reason to believe that it is likely to have fluctuated as much in indirect response to investment in agriculture as in direct response to the quality of the vegetation and the climate. In recent decades the condition of pastoralism has been similar to that of irrigation, in that grazing lands appear to be in a state of ecological decline. In the case of pastoralism, population growth and external economic and political factors, such as change in the terms of trade, have often led to patent imbalance between animals and vegetation.
The resulting ecological change and damage is less sensational than that caused by the enormous investment in irrigation, but whereas only a few million hectares are at risk from irrigation, literally hundreds of millions of hectares are judged to be at risk from pastoralism. A major part, therefore, of the efforts to develop or modernize pastoralism (apart from arguments about the viability of traditional forms, especially nomadism, in the modern world), as with irrigation, has been devoted to counteracting what are assumed to be the adverse ecological effects of the history of that technology. The challenge of pastoral development was recognized somewhat earlier than with irrigation to be a problem of organization, but it was concluded that pastoralism should therefore be reorganized along lines similar to its recent evolution in the West, especially in the American West and in Australia.
Since modern irrigation engineering was developed in situ beginning outside the West in India (though by a colonial power) over a hundred years ago - its ecology has also been studied in situ, and is generally well understood. On the other hand, however well the ecology of modern (ie Western) pastoralism in the West may be understood, that understanding may be inadequate when applied elsewhere in the world where not only the history of the vegetation but the history of co-adaptation between sociocultural and natural factors is different. The questions that must be answered in regard to pastoral development are both ecological and social. They include the history of the vegetation in relation to particular pastoral technologies, as well as the social constraints and incentives that keep people in or push people out of a pastoral adaptation. Unlike irrigation, which is a new technology demanding new forms of organization, pastoralism already exists embedded within its own social forms. In order to make the most of existing systems, it is necessary to investigate in detail the adaptive relationships between vegetation, animals, and productive strategies of the pastoral population. This investigation has scarcely begun; what has been done so far, however, suggests that modification of the present situation solely on the basis of Western experience could be as damaging to long-term human interests in natural resources as a policy of noninterference, since such modification breaks down existing systems and dissipates both the human resource and the heritage of local environmental knowledge.
The most significant difference between the irrigation problem and the pastoral problem is that the former is a technology essentially industrial and exotic, so that the need for a new organizational structure to implement it is obvious. The latter is traditional. How the productivity of traditional forms of pastoralism might be increased and their environmental problems alleviated is a question that has not been sufficiently investigated. (A rare example in South-west Asia is in Martin 1982b.) Instead, as a result of the cultural difference between pastoralist and planner, it has been assumed that exotic forms of management of range vegetation or animals should replace traditional forms, despite the fact that the traditional forms were developed in conditions that were different in terms both of natural resources and of cultural perception and the market context. Nevertheless, both the irrigation and the pastoralism problems in South-west Asia pose problems of organization.
Some mention must also be made here of rainfed or dry farming since it has been an important historical complement of both irrigation and pastoralism. Although it is less important as a source of development problems, in South-west Asia the extension of dry farming onto unsuitable surfaces as an indirect result of development, or simply of modernization, has been doubly damaging, since it has led not only directly to soil erosion, but indirectly to overgrazing on poor ranges, in that it deprives pastoralists of their better pastures.
In terms of national economies and possibly also of overall economic significance, the most pressing environmental problems for the development of food production in Southwest Asia are those of waterlogging and salinity in the Indus Valley in Pakistan and of ecological decline on the rangelands of Iran and Afghanistan. Progress on the solution of these problems in these countries would constitute an important step toward the solution of many similar problems elsewhere. Work has been carried out on a large scale on purely technical solutions for both of these problems since the 1950s, but progress, though not insignificant, has lagged decidedly behind expectations. Although it has been proven in some cases that foreign experts are able to correct ecological problems and run similar systems without causing similar problems, the local populations continue to produce the same problems. The purely technical solutions must, therefore, for all their value be judged inadequate.
Finally, a comment is necessary on the scale of the following case studies of irrigation and pastoralism. The advantages or disadvantages of an exclusively technical solution would be best illustrated on the scale of a single project. Where ecosystems are the focus, a holistic study must be on the scale of the ecosystem. In the case of a human socio-economic focus, where the context of behaviour is the national economy, and the cultural, linguistic or religious grouping, a much larger scale is required - a larger universe of study. The process of decision-making is the core of the problem (Cf. Bennett 1976, Britan and Denich 1976), and it will not be understood unless the context of decision-making is allowed to determine the boundaries of the investigator's universe of study and of the planner's attention. If we are to break out of the succession of piecemeal, ad hoc, or middle-range solutions of local problems which, whether they work or not, prove nontransferable, it is necessary to change the scale of investigation and, at the same time, the orientation to the problem. Even the most productionoriented planner should logically focus on the human population because human labour is an essential resource, and not the most tractable, in any production system.
Therefore, any project - research or implementation should be designed and executed with due regard to the ecosystemic, the social, and the cultural context or universe of the problem. The fault in responses to the development challenge so far is that they have not been radical enough, in the sense that they have not gone to the human roots of the problem before designing the solution. If we are to make progress in development, it is necessary to leave the relatively safe and well-trodden methodological ground of small-scale technocentric and eco-centric case studies, and try something new, even though the theory for it may not yet have been fully worked out.
The remainder of this chapter reviews the two primary food producing technologies in South-west Asia with the aim of demonstrating the inseparability of investment and engineering from the constraints not only of ecological context but of social and cultural embeddedness. The purpose of the review is to show how the integration of all these factors might be achieved in development planning by systematically pursuing each of the three dimension secology, society, and culture - of the man-environment relationship.
I. Irrigation in South-West Asia
The case of the Punjab (Pakistan)
Comparative situations
The case of the Punjab (Pakistan)
The environmental change caused by perennial irrigation in dry lands is spectacular. Both the change and the enormous investment it requires is more than justified by the similarly spectacular increase in productivity. In Pakistan today irrigation provides the major component of agricultural production, which is over a third of the country's Gross National Product. But the tremendous potential of the (natural) resource and the technology (on the drawing board) is frustrated in the application by ecology.
The growth of the ecological problem makes better sense when subjected to historical review. But the development record does not appear to have benefitted from such a review. The lessons to be learned from such a review become plainer when seen from the point of view of the individual farmer. The implications for policy are clear, but may be difficult to follow because we are so unused to integrating socio-cultural with economic, technological and ecological information.
Let us begin then with a brief description of the resource and the technology. The facts and figures are taken from Michel (1967) and the Water Management Technical Reports on Pakistan produced by the Consortium for International Development, especially Corey and Clima (1975), Eckert et al. (1975), Mirza (1975), and Radosevich and Kirkwood (1975). The cultural material is taken mainly from Merrey (1982).
The resource and the technology
The average total annual flow of the Indus River system in India and Pakistan is twice that of the Nile and 10 times that of the Colorado. It exceeds 170 billion cubic metres but, as is typical of dry lands, there is great seasonal variation in flow. Between November and February, the flow averages only one tenth of what is normal for the summer monsoon months. More direct rainfall adds an average 7.5 billion cubic metres to this resource each year and it is estimated that some 54 billion cubic metres can be taken annually from groundwater. Twenty four and a half billion of these are presently accessible, but because of greater salinity they must be diluted by mixing with river water before use. Generally the quality of river water is good, with 1 to 300 parts per million of dissolved solids. The whole system commands 15.5 million hectares in which soil quality varies from moderately fine and deep alluvial deposits in the flood plains to coarser deposits on the higher ground (bar) between the rivers. As is to be expected in dry lands, there is a general lack of organic material.
In 1947 the Partition of India and Pakistan caused a de facto division of this resource, which was formalized in the Indus Waters Treaty (1960) by which Pakistan received exclusive use of the Indus itself, plus the Jhelum and Chenab tributaries, leaving the Beas, Ravi and Sutlej (amounting to a little over twenty percent of the total average annual flow) to India.
The irrigation system that has been developed over the' last century and a quarter now diverts within Pakistan approximately 123 billion cubic metres of annual river flow and spreads it over 13.5 million hectares of cultivable land, of which nearly 9 million hectares can be irrigated throughout the year.
This controlled distribution is accomplished by means of 17 barrages and canal diversion works, 42 major canals, 6,000 kilometres of minor canals, 600 kilometres of link canals, and 78,000 watercourses. The total capacity is nearly 7,000 cubic metres per second, or 250,000 cubic feet per second (cusecs) as it is commonly measured. This flow is supplemented from 156,000 tube wells which raise 24.5 billion cubic metres from the subsurface water table. The overall pattern of flow is from one of the major rivers to major and minor canals through outlets (moghas) to watercourses (khals) to farmers'fields. What is not consumed as it passes through the system is either returned to the rivers or disposed of in some other (often more costly) manner or accumulates, resulting in waterlogging and salinity. Since 1955 a large network of surface drains has been created as part of a programme for the solution of this problem.
The purpose of this technology is to control the spatial and temporal flow of all the available water over the greatest area of cultivable land in order to achieve maximum distribution and optimum quantity and speed of flow. The speed must be slow enough to minimize erosion of the bed and banks of the canals. While the horizontal movement of the water within the system is controlled relatively efficiently, vertical movement out of the system has proved more difficult to manage. The system is vulnerable to seepage and evaporation. By spreading surface water over a much larger area or "command" than it would naturally cover between two points in a stream channel, and by causing it to spend more time in the commanded area than it would spend in the channel, any irrigation tends to increase the amount of recharge to the water table. Once the water has passed both below the root zone of the crops and below the level (approximately 3 metres in the sandy loams that predominate in the Punjab) from which capillary action can raise it to the root zone, it becomes valueless, unless it can be pumped out again.
Excessive recharge causes the water table to rise. If it rises to the level where it interferes with plant growth by waterlogging, or if capillary action combined with evaporation increases salt accumulation in the upper soil horizons or on the surface, productivity is reduced.
The interrelation of efficient control of water with crop requirements demands not only complex engineering but sophisticated organization of labour. Altogether this form of irrigation is at once the most large-scale, most investment-intensive, and most economically significant technology of food production in human history. Both as an economic or social and as an ecological or natural system, it is qualitatively different from what preceded it. It might be expected, therefore, that development would require complete reorganization of the human population that works it. In fact, however, there appears from the beginning to have been a conscious policy on the part of the developers not to interfere with local practice. Formal irrigation administration as it has evolved from the beginning reaches down to the level of the canals and their outlets only. Lower level officials report water flow, regulate distribution gates, and organize maintenance work. There are now also tube-well operators. But from the canal outlets onwards the farmer has always been left to his own devices. He has had to align, dig and maintain his own watercourse and develop a rotating water delivery or distribution system in cooperation with his neighbors, without the benefit of any outside assistance or advice. There is often only one outlet per village and no congruence of watercourse-sharing communities with other social or spatial groupings of the population. The development of this resource and of the technology to exploit it has not been complemented by attention to the human resource without which it cannot be exploited, let alone by a comprehensive plan to manage both the physical and the human resources as a means to improving the wellbeing of the society.
The ecological problem
The greatly increased level of productivity per hectare is not sustained. As a result, increase in gross sown area cannot keep pace with population growth. In fact, even by the time of Partition the Punjab had ceased to produce any substantial grain exports. Even though Pakistan inherited almost all the surplus-producing irrigated areas, the combination of population growth and ecological damage quickly - by the mid-1950s - made her a net importer of her major crop and food staple, wheat.
The principal problem arises from the loss of cultivable land through waterlogging and salinity as a result of seepage, poor maintenance of watercourses, and inefficient application of water to crops. About half of the total irrigated land is estimated to be affected to varying degrees. Until recently the process was counteracted only by bringing more land under cultivation. Paradoxically, a subsidiary but related problem caused by water loss through these same processes and through evaporation, is lack of water.
Before the development of the system, water-table depths over most of the area now irrigated were about 24 to 28 metres. Historical data indicate that the water table has risen an average of 15 to 35 centimetres per year since modern irrigation was introduced. Of the 123 billion cubic metres diverted annually, only about 71.5 billion cubic metres reach the heads of watercourses. it has been estimated that from 5 per cent to as much as 65 per cent per mile is lost in the watercourses. Altogether, less than 30 per cent of the water diverted from the rivers gets to the root zones of crops and is consumed. Further, a salinity of 1,000 parts per million is acceptable for virtually all crops, but groundwater of that quality which evaporates at a rate of half a metre per year, a typical rate where the water table is less than a metre deep, will in 20 years raise the salt content of the top metre of soil to about 1 per cent, which is too high for even the hardiest crops. Not only, therefore, are environmental problems causing loss of cultivable land, but the irrigation system is working at only 30 per cent efficiency, and this inefficiency is responsible for the disastrous loss of both land and water. These processes are almost certainly exacerbated by inefficiencies in actual cultivation. But these inefficiencies are disguised, because of the administrative segregation of irrigation from agriculture, which is characteristic of the way bureaucratic systems evolve (Cf. Spooner 1982a & b). In the 1960s it was estimated that between 20,000 and 40,000 additional hectares were being affected each year and, in the worst districts, 40 to 50 per cent of the cultivated land was already severely damaged.
Unfortunately, there is no exact method of quantifying waterlogging and salinity damage. Actual conditions vary from season to season, and year to year, depending partly on the strength of the monsoon and partly on other factors such as spatial variation in rainfall, groundwater recharge, and evaporation. Actual crop damage varies according to the sensitivity of the particular plant. Surface salinity has been compared to skin rash appearing in blotches which vary continually in intensity and extent.
Finally, it is possible that the ecological problem is caused by inefficient practice of the technology. Perhaps highlytrained farmers would be able to apply it without allowing excessive recharge to the water table. In this case the fault lies entirely in the neglect of the human component in the planning process. On the other hand, any such possibility remains to be proven. Perhaps the technology is deficient, and the fault lies entirely with the engineers and investors! The likelihood is, of course, that there are inadequacies in the technology and inefficiencies in the application, as well as incongruencies between the requirements of the technology and the perceptions of the farmers. But we do not know. Our knowledge is still almost exclusively technological and ecological. And what we do know about the people who use the technology has not been systematically related to their use of the technology. We tend habitually to keep our knowledge of resources and technology categorically separate from our knowledge of the way people behave and think.
The history of the problem
Before the middle of the 19th century, irrigation was confined to parts of the flood plains and was mostly seasonal. Pastoralism was the major form of land use, but was supplemented here and there by dry farming. Water was drawn during the summer when the rivers rose above the levels of canal inlets, and was used to irrigate lands which would not have received water by natural flooding. Such canals were, however, uncontrolled and did not allow exploitation of low river flows. Only relatively narrow strips of land along the rivers could be irrigated. The supply channels were inefficient: they depended on uncertain river flows and tended to silt up. There were also dangerous breaches during the flood season. In spite of these shortcomings, inundation canals constituted an important advance in the technology of irrigation. The system was subsequently improved during the Mughal period, especially in the 17th century, to the extent that limited perennial irrigation was possible in parks and gardens.
The traditional systems were designed to spread the water over as large an area as possible during the period of maximum flow. Limited engineering works maintained a constant level of water suitable to the level of the land to be irrigated, "heading up" the flow of water and distributing it though a system of canals. The modern system, construction of which began in 1851 and has developed steadily ever since, is designed for continuous control.
The motivation of the colonial government in embarking on this vast and innovative engineering scheme is in itself instructive. Like more recent motivations for further development of it, and for the development of similar projects elsewhere (for example, in Iraq, Afghanistan, Egypt and Soviet Central Asia), it was at least as much political as economic. The desire to appear to have improved on the engineering of earlier regimes provided the general motivation, while the immediate need to ensure against the threat of famine and to settle the recently-disbanded Sikh levies, were the specific motives. The guiding principle was uncautious optimism rather than careful research and planning, despite the complete lack of relevant experience. In addition, the colonial administrators wanted to expand the area under irrigation and bring new lands into cultivation so that they could be settled and taxed. Ancillary motives included re-settlement and relief of crowded conditions elsewhere,. the creation of a granary which could supply the famine-prone areas of north central India and, later, especially in Sind, creation of new areas for cotton production. The optimism inherent in these motivations hindered clear perception of the environmental problems that soon developed.
It is important to note the role played by perception. For decades there seems to have been a general tendency to ignore or misinterpret what now (with the benefit of hindsight) appears to have been obvious contrary evidence about the success of the technology. For example, on the Western Jumna Canal of the Ganges Basin (where the development of irrigation had begun, in what is now India, with the provision of permanent headworks in 1836), waterlogging and salinity problems had already appeared by 1859. Between 1870 and 1880, the irrigation channels were re-aligned and natural drainages cleared, with results which were encouraging but did not lead to a general policy for dealing with what was already becoming a general problem. When the Lower Chenab Canal, which opened in 1892, had produced serious waterlogging by 1908, some maintained the cause lay not in irrigation but in the fact that the canal, road and railway embankment were interfering with surface run-off, or even that the Punjab was in a rainy cycle. Others maintained that a high water table was actually an advantage, because it facilitated the operation of hundreds of Persian wheels in shallow wells and produced some regeneration of water supplies by seepage during the dry season. A Waterlogging Enquiry Committee was finally established in 1925, but still there was more interest in extending the system onto new lands than in reclamation, despite the growing awareness that the cost of bringing water onto new lands was increasing, the new lands had much coarser soils and lower initial fertility, their seepage and evaporation rates were higher, and even the Indus Basin would eventually run out of new land to replace the old in any gravity-fed surface-water irrigation system.
Partly as a consequence of the non-ecological motives and the unrealistic perception of the situation that they engendered, the cropping pattern was dominated by wheat which was the staple grain, and cotton, the obvious cash crop, which both made it feasible to spread the water thinly. However, even these crops, which have low water requirements, received much less than the optimum, and although sugar cane, which requires more water, was allowed to a limited extent, rice cultivation which would tolerate higher accumulations of salt as well as using more water, was generally discouraged, at least until the water table had risen close to the surface.
It is clear that even apart from the neglect of the social dimension there was a significant degree of wrong-headedness in the history of irrigation planning in the Punjab, and it is not surprising that it should take considerable time and intellectual pain to rethink it.
The development record
Since the 1950s efforts have been made to reduce evaporation and seepage but only to the extent that the cost appeared economically justifiable in the context of the perception of the problem. Apart from the policy of spreading the water thin, which had always carried an economic rationale, canals were re-aligned in badly leaking places. Some canals were lined and some surface drains were reconstructed. These practices have been continued up to the present. They have included no social component, and have had little impact on the general problem.
The most promising technical attack on the problem was a type of comprehensive control strategy. However, although such a strategy was proposed as early as 1927, it was not approved until 1944 and not put into full operation until 1952. In an effort to both lower local water tables and provide additional supplies of irrigation water, 21,257 tubewells were sunk along badly seeping canals in two of the interfluves. Although this scheme (known as the Rasul Scheme) was not particularly successful, because most of the wells were too close to the canals and actually accelerated seepage, it did lead to a better understanding of the problem. It was followed by a second similar scheme in 1953 - 4, and a third in 1957- 8. Finally, when the Water and Power Development Authority (WAPDA) was established in 1958, it was specifically entrusted with "prevention of waterlogging and salinity and reclamation of waterlogged and saline lands." At last the problem had been officially recognized, but the diagnosis was exclusively technological.
WAPDA's Salinity Control and Reclamation Projects (SCARP) have steadily increased the number of tube wells ever since. The factor which differentiates these projects from their predecessors lies in the concentration of these tube wells in fields of from 1,500 to 3,000 units, each with three to four cusecs (85-110 litres per second) capacity, and each serving approximately 250 ha. The capacity and spacing of the wells is designed to allow full control of the drainage in each project area.
Combined with supplies from an even greater number of privately owned one-cusec wells, and the enhanced surface water supplies made possible by the newly constructed Mangla and Tarbela dams on the Jhelum and Indus Rivers, the amount of water available for irrigation in Pakistan is now estimated at over 100 million acre feet or 1,233,438 million cubic metres. Two-thirds of this supply is from the surface water storage and distribution system, and almost one fourth from the government-owned tube wells. The total supply represents a substantial improvement over the 68 million acre feet or 838,772 million cubic metres available in 1965 and thus enhances significantly the capability for efficient irrigation of crops and for leaching of salts from the top soil.
This increased amount of water spread on the surface, however, would serve only to increase the waterlogging and salinity damage to soils and crops - except that the massive concentration of high capacity tube wells offers the hope of controlling the level of the water table. But a further problem is the quality of the ground water. Wherever the ground water is of usable quality (up to roughly 2,000 parts per million of total dissolved solids, depending on the chemical composition of the salts), its use for crops should produce a net gain, and through consumption and evapo-transpiration result in a gradual lowering of the water table. In other areas, saline ground water must be mixed with surface water of good quality before being applied to crops. To accomplish this mixing, canal capacities in certain areas need to be enlarged. In some areas, the ground water has proved too saline even for blending and must, therefore, be exported, either by the rivers (which will cause problems downstream), or via new wasteways constructed for this purpose.
Although the technical problems of the SCARPs have been overcome, and the projects have caused a significant improvement in the situation, they are nevertheless still inadequate. For example, in SCARP no. 1, which began in 1962, the water table has declined to an average of two to three metres. below the surface, and about 45 per cent of the affected area was reclaimed in the first nine years. Subsequently, however, progress was rather slow - a development which has been attributed to the sodicity of the soils. Generally, yields have improved as a result of land drainage, reclamation of considerable areas, and increase of water supplies from tube wells, together with additional agricultural inputs, such as fertilizers. In one experimental project area the gross value of agricultural produce - both crops and livestock increased by a factor of 2.5, but deterioration in groundwater quality is causing adverse changes in chemical characteristics of the soils and decline in the yield of sensitive crops.
Pakistan's groundwater and reclamation programme represents an extremely complex and costly effort to offset the consequences of inefficient surface-water
irrigation. For the periods of Pakistan's third and fourth fiveyear plans (1965-1975), the total cost of government owned tube wells, canal remodelling and drainage works (not including surface water storage) was set at about US $1,100 million, or slightly more than the cost of the Tarbeia Dam which itself represents roughly half the total cost of the Indus Basin project. It was expected that the gains achieved in Pakistan's agricultural sector, which grew at a healthy rate of 3-4 per cent per annum between 1960 and the early 1970s (though most of the gain was due to nonfood crops), would eventually more than compensate for these investments. But it was understood that these gains would depend not only on increased surface water and ground water supplies, but on further input of fertilizers, improved seed varieties, insecticides, and pesticides, and improved techniques of irrigation and cultivation. Generally, it was recognized that although reclamation programmes must be continued, the best hope for future progress lay rather in prevention. It remained, however, to develop a clear strategy for prevention.