|Freshwater Resources in Arid Lands (UNU, 1997, 94 p.)|
Moderator: Juha I. Uitto
Uitto: We have heard presentations on a variety of water issues. Now I would like to ask each of the speakers for one more round of comments - after having heard the other speakers and having had time to reflect on the issues.
Hillel: I would like to speak for a few minutes about the efficient use of water. For too long, the problem of water was regarded completely as a problem of supply. When there is a shortage, we get the engineers to build a dam and to design pipelines or canals to bring water to where it can be used. The problem of the use of water was ignored, and so we find that as water is becoming more and more scarce and precious, as the easily accessible water resources are subscribed, it is becoming more difficult to get more water for additional supplies. At the same time, the paradox is that we use water very inefficiently. Everywhere we go, we see that water is wasted, used excessively. That not only wastes a precious resource, but also produces environmental damage.
Applying too much water to the land causes the land to be saturated. There is a restriction of aeration in the soil and gradually the water-table rises, especially in river valleys, and then by capillary rise the water-table comes close to the surface. It suffuses the ground and evaporates on the surface, accumulating salt, and this salt poisons the soil. This has been the failure of past civilizations in Mesopotamia and other places, and it is still rampant today in many parts of the developing world and especially in the so-called developed world, in California and Arizona, and in Australia and in Israel. In many parts of the world that depend on irrigation, irrigation has become unsustainable, and about a third of the land under irrigation is subject to salinization and waterlogging. This also has the effect of increasing the cost of irrigation, because it requires the installation of very expensive drainage systems. Additionally, we then have the problem of how to dispose of the effluent of drainage, which is loaded with salts and, when thrown into the river, poisons the river for users downstream.
So the problem is how to use water more efficiently in order to prevent environmental damage, in order to get a better return for the expense of water that we supply. Unfortunately, many irrigation systems have waste built into the system. They provide no incentive for the users to economize on the use of water, and no technology, no inducements, and no public awareness of the efficient use of water. As we come to the end of the twentieth century, the end of this millennium, the emphasis must shift from the supply side to the demand side. There is a great amount of water to be had from conservation, from more efficient use of water. We must create the administrative systems, the technological systems, and the frame of mind that induces water saving and efficient, more careful use of water in agriculture, in industry, and in the domestic sector. We all use water very inefficiently. There is a tendency of human beings to think that if a little bit of something is good, then more must be better, and much more must be much better. That's wrong. In irrigation, as in many other activities in life, just enough is best. Too little is not good because it does not produce the desired effect. Too much is not good because it creates waste and damage. Fortunately, in the last 15-20 years there has been a revolution in the science of irrigation - in the water supply and water use for crops. We have been able to develop techniques for the precise application of water to the roots of crops in a quantity and at a rate that is exactly adjusted to meet the demand of the crop. As the crop grows from a very young crop to a greater coverage of the ground, its water requirements increase. As the temperature rises and hot air blows over the surface, the water requirements increase. As the crop matures, its water requirements diminish. And so an irrigation system must be very flexible and be based on precise measurements and knowledge of how much water to apply and not to apply any more. We now have the devices to do this by applying the water drop by drop, or in very small volumes, rather than by flooding the land - which is the traditional form of agriculture - so that the soil never becomes saturated and the root zones are kept at an optimal condition of water. We also have the techniques to inject nutrients into the water supply to fertilize the crops precisely, so that we apply the fertilizer together with the water much more efficiently.
Because of the way these systems are developed in the industrial countries, they are very expensive. They are automated and computerized; there are such components as sensing devices, pressure regulators, filters, and sensors for wind direction. All this is helpful because it saves labour in the industrial countries, but it does not need to be so complicated and expensive. It is possible to take the principles of these systems and simplify them to fit the needs of farmers who are not rich. We can make irrigation a small-scale operation for farmers who do not have much money but who do have the need, and the intelligence, and the incentive of modern efficient irrigation to create enough food to feed the people of the coming generations. If we cannot mobilize water efficiently to enhance food security, we will have a terrible crisis as the population arid regions continues to increase and as the rain-fed supply continues to degrade through the processes of desertification. Not only is the task now to make more water available but increasingly the task is to make better use of water, more precise use of water, by managing the demand side.
Wang: First, poor water use and management already cause agricultural environment degradation in arid regions. In China, the water use is really very poor and much of the water resources is wasted by this unreasonable management. Flood irrigation uses a very great quantity of water for very small areas. If we improve the efficiency of water use, then we can have sustainable development in those regions. It is unacceptable to allow that kind of environmental degradation to continue, because there is no place for the people from arid lands to move to when the land becomes uninhabitable.
Secondly, the arid regions are considered by the central Chinese government to be important for development in the twenty-first century in order to accommodate the population increase expected in the eastern part of China. More space can be found in the arid waste area, which is a wide area and, under proper management, people can be moved from the east part of China to the west part of China.
Third, efficient water users should be rewarded with financial and technological advantages. Water management in the Negev Desert is a good example for China to follow.
Lastly, implementing sound water-management practices can sometimes be a problem. For example, traditionally the local people think that water is something that comes from the sky as God's gift to them. So the local government might have some regulation charging for water, but the farmer refuses to pay, saying "We have used the water for free, generation after generation why do you want to charge me now?" We have also shown them conservative ways to use water but they do not follow them. One reason is that they have too little education to determine which way is better. The second reason is that they are poor. They have no money to buy even very simple conservation equipment. These are also important issues regarding efficient water use.
Kayane: I would like to add two points. One point is about the science of hydrology. The science of hydrology has progressed very rapidly during the past 10-20 years. Most important is the development of new techniques we can use - specifically the isotope technique - which can tell us about changes in climate. For example, the record in the deep ocean sediment cores: microcreatures built their skeleton structure in ancient ocean waters using hydrogen and oxygen, of which we can analyse the isotopic ratio. Past climate changes can also be revealed by analysing the isotopic ratio of continental glaciers. This technique can also be used to study groundwater movement or the hydrological cycle. To utilize these techniques fully, engineers and hydrologists must cooperate closely.
The second point is the data issue. The amount of data in the world is steadily increasing. Observation methods have improved: for example, remote-sensing methods have become very useful in obtaining more precise data. To store and analyse these data properly, it is very important to create a database, which should also include isotopic compositions.
Abdulrazzak: In the Arabian Peninsula, overdevelopment of water resources has created many environmental problems, especially in terms of groundwater resources that are non-renewable. So the region has to look to the future, decide for how long this resource needs to be used - 20, 50 or 100 years - and minimize pumping to accommodate that decision.
The second point is management. I think the management of water resources is overdue. The problem that I see in our region is that sometimes there is poor communication between scientists and decision makers, and sometimes management is fragmented. In our part of this arid environment, management has to be integrated. Capacity building has to begin at the lowest level by educating the public. You have to introduce laws and regulations and modify them so that they can be monitored. All kinds of incentives could be implemented to reduce demand. Domestic demand is very small, but more effort is needed. The local agriculture sector is consuming substantial groundwater resources in that area we can have better efforts to save that water for future generations. For better management, we need a better assessment of our resources. We have to see which available technology assists our resources better, so that we can manage it properly. The more we know how the system works, especially for this delicate environment, the better. We need to understand the system so we can manage it much better. We need to put more emphasis on supply augmentation, we have to encourage research and development, and we have to give more weight to technological development.
The last point I want to make is that the countries in that region have to exchange information and know-how. Some countries have more experience than others and we all have to learn from each other. There is much work in this arid environment to integrate the resource management for development for the future.
Osuga: A point that I could not cover sufficiently earlier is that the efficient use of construction of underground dams in arid areas is not absolute. Certain requirements are to be satisfied if you were to implement this technique. There should be an aquifer of wide areal extent and below that an impermeable area supporting the aquifer. There should be an ample amount of recharge and an underground valley should exist where the underground dam can be constructed. The underground reservoir should have no interference from poor-quality water.
The benefit of this approach of using an underground dam is that you are able to maintain the use of the land above ground, for example elementary schools and facilities and fields. They don't have to be removed and the people don't have to be evacuated during construction of this dam because existing facilities and buildings above ground can be maintained.
In case of damage caused by an earthquake, such as cracks in the wall, there will be no overall detrimental effect or injuries to people. There is only a rather limited effect of the wall, which does not have to be bulky - a sheet of vinyl can be a cut-off wall. Regarding the dam's impact on the water cycle or deteriorating the quality of the water through seepage or storing the water, take nitrous oxide as an example. The limit is 10 ppm. Prior to the Sunagawa Dam construction, the concentration was above 10 ppm; after completion it went down to 6-7 ppm. We may need to conduct a comprehensive study on the proper use of fertilizer and maybe switch over to organic fertilizer and treatment of household organic wastewater.
El-Habr: We have heard a lot of talk about agriculture in arid lands, demand management, sustainable development, but let me remind you that thousands of people, especially children, die every day due to lack of safe water, due to lack of sanitation - that is also something that we have to think about. It is the equivalent of 75 jumbo jet crashes a day. People are dying from lack of water in arid lands. We cannot continue to do business as usual. We should think in a holistic manner. Sustainable development and use of this precious resource should be on a basin scale.
Kobori: I must speak as a scientist living in Japan where there are no arid lands, so the Japanese experience arid lands only outside Japan. The point of Japanese cooperation in all kinds of freshwater issues in arid lands is that we have several tools, for example a research satellite with radar which gives us very good images for research for case studies in countries such as Saudi Arabia and China.
As to the desalinization efforts on the Arabian Peninsula, currently there is enough revenue to finance such large-scale projects. But what if the revenue disappears in one or two centuries? We must also look at cheaper methods like reverse osmosis that will be feasible in the future.
Concerning water research, we have many institutions. For example, in Japan they number two or three for groundwater only. We also have a liaison committee for water issues. Internationally speaking, there are some international groups, but no regional or global associations covering all aspects of water research. I understand that international committees are now being established, and this effort needs to be supported.
I would also like to mention a big philosophical problem - people in arid regions often need so-called government (or even non-government) aid, but in the final analysis they need to become self-sufficient. To what extent should we support international cooperation or projects in developing countries?
Finally, I think we need more money, a big budget. It would be easier if we stopped armament and wars completely. These moneys could then be used to protect resources, not only water but all resources for our children. In this light, I would like to conclude with a quote from the ancient prophet Isaiah: "Nation shall not lift up sword against nation."
Uitto: I hope your wish comes true. Unfortunately, it looks as if some nations might go to war because of water. I would now like to open the floor to discussion.
Mr. Takashi (Irrigation Engineer, International Development Center of Japan) to Hillel: You said that these ancient water-harvesting methods are applicable today no less than in the past, as evidenced by the effort of constructing ancient farm units in the Negev. Is that still at the concept stage or has it been realized as a full-scale project? If it has been realized, what is your experience with the pilot project? Specifically, where did a salinity problem occur, and how much cost did occur in addition to a similar irrigation project built in a humid zone? These techniques could be applied to the entire Sahara region or other desert areas to solve the global food problem, so what do you propose to agencies concerned with food production?
Hillel: Has water harvesting been proven sufficiently to be put to use in Israel or elsewhere? The answer is not so simple, because where water is available for irrigation by inter-basin transfer or by drawing from groundwater, it is easier to put in perennial irrigation. The system of water harvesting becomes necessary when there is no other water any more, when water resources are depleted, or when all of the available water is already put to efficient use, and that is not yet the case in Israel. We know that it is a possibility but it is not being done on an economic scale for crop production. However, it is being done in Israel now to reverse the process of desertification, a process called savannafication. It is taking desert fringelands and building structures to trap natural run-off and to encourage the growth of vegetation in areas that have been denuded of vegetation through many generations of overgrazing. This is turning a bare landscape into a savanna-like area of some trees, some shrubs, some grass, on land that would otherwise be completely naked.
The real question is whether this type of approach can help to reverse the process of land degradation in Africa south of the Sahara, because this is where desertification is most extreme and this is where many people are now deprived of livelihood and moving off the land and aggregating in big cities without infrastructure, employment... We see the results in such countries as Somalia, Rwanda, Liberia, and Burkina Faso, where we are facing a crisis. I believe these systems can help but they have not been applied on an appropriate scale. Some agencies of the United Nations are aware of this; the Food and Agriculture Organization is very aware of it. The World Bank, which is the biggest agency for international development, is unfortunately biased in the direction of large-scale projects. The World Bank is a lending agency, it has to turn around money every year - so it does not have the patience for small-scale development for small farmers, which is the traditional mode of the countries in sub-Saharan Africa. We need an approach that is more patient, more flexible, less grandiose. Local politicians, too, favour grandiose schemes, because they can be very proud of these schemes rather than small-scale projects which are fitted to the ecology of the land and to the people living on the land. We know much can be done, we know that there are resources that can be used better, so it calls for a new approach.
The question of cost is a very difficult one, because costs vary from place to place. From time to time there is drought and people are deprived of a livelihood and there is war or movement into cities - how can you assess the cost of that compared with the cost of facilitating local social, economic, and technical and educational development from the ground up? I believe the job needs to be done; it has not yet been done on a sufficient scale - not in water harvesting, not in rainfed farming and water conservation, and not in irrigation. Irrigation, for example in Africa, is extremely underdeveloped, except for North Africa and parts of East Africa. Most of the countries of the Sahel region and most of the countries south of the Sahara suffer from underdevelopment in the area of irrigation and water resources. That is the key to ensuring food security in the future.
In closing, I would like to refer to the prophecy of Isaiah mentioned by Professor Kobori, which is the motto of the United Nations - that nations should transform swords into ploughshares and that they shall learn war no more. But I must say, in the way of warning, that ploughshares can do as much harm as swords if they are used badly on the land and if they cause erosion and desertification. We have to use ploughs carefully, too, as they can be instruments of environmental destruction. So it is management of the land and the water that we must learn to do much better.
Dr. German T. Velasquez (United Nations Centre for Regional Development): In the future it would be possible for countries to go to war because of the limited amount of water, but we also have to realize that it is also possible for countries to go to war because of mismanagement of an oversupply of water - for example, the cases of India, Nepal, and Bangladesh, which we also have to consider. It is unfortunate that, even though the United Nations considers both issues quite important, there has not been a chance to combine disaster management with environmental issues. Sustainable development is defined by three factors: economic viability, political acceptance, and environmental integrity. Maybe we can add a fourth, which is disaster mitigation capability. We have heard that water management is an important issue of the future. We might expand that to include not only the management of a limited amount of water but also the management of an intermittent oversupply of water.
Uitto: The point about disaster management in the environmental context is a very valid one, especially in light of the degradation of the resource base. In some cases, this degradation has been so severe that it has created crisis conditions, giving rise to environmental refugees.
Hillel: I have spent the last few years studying the potential and actual conflicts resulting from shared resources in the Middle East and the uncoordinated use of these resources, and I've come to the conclusion that in each case the problems of rivalry can be solved much more cheaply than going to war; that the cost of resolving the issues to the satisfaction of the parties by compromise and cooperation to make more water available and to make better use of the water - all these are much more economical than even a small war. War is the most expensive way to solve a problem, not just in terms of the material cost but also in terms of the human cost. The New York Times reported that Arab economists calculated the cost of the 1991 Gulf War as US$677 billion. That is only the assessable cost the bridges and roads that were destroyed, the armaments that were destroyed - but not the human suffering. How much good could US$677 billion do in terms of water-resources development and research, and employment and education?
War is the most wasteful, the most expensive way to solve a problem. In Roman law, the term rival was a neutral term that meant a neighbour along a stream. They can either compete or cooperate. We have forgotten the option to cooperate and invested the word with the meaning of competition and conflict. We have to go back to the original meaning of the word, which gave the option of cooperation rather than competition and conflict. Through cooperation, of course, I believe, all of these problems can be solved.
Abdulrazzak: With respect to the management of oversupply, I agree that management has to be done to reduce the impact of damage. Even in arid lands you sometimes have to deal with oversupply in terms of flash floods, which have to be managed to reduce the impact. Flash floods in arid environments can be quite disastrous because people are not prepared. So even in arid lands there is a requirement to develop flood plans and build dams in order to deal with a short-term oversupply of water.