농업과 물 -세계 물의 날

Why is water a key to food security? Food security exists when all people at all times have both physical and economic access to sufficient, safe and nutritious food that meets their dietary needs for an active and healthy life.  People who have better access to water tend to have lower levels of undernourishment. The lack of water can be a major cause of famine and undernourishment, in particular in areas where people depend on local agriculture for food and income. Erratic rainfall and seasonal differences in water availability can cause temporary food shortages. Floods and droughts can cause some of the most intensive food emergencies. Video Interview on Water  for Agriculture at FAO Water >> Drought is still the #1 problem  Drought ranks as the single most common cause of severe food shortages in developing countries. Drought caused more deaths during the last century than any other natural disaster, and Asia and Africa rank first among continents in the number of people directly affected. (Below, E. et al., 2007.)

How much water is needed to produce our food? All the food from crop and livestock production, inland fisheries or aquaculture, forest products, requires water. This water comes from rain and moisture stored in soils (green water) or from withdrawals in watercourses, wetlands, lakes and aquifers (blue water). 70% of the blue water withdrawals at global level go to irrigation. Irrigated agriculture represents 20% of the total cultivated land but contributes 40% of the total food produced worldwide.

Water footprint  All human activities use water: drinking, cooking, washing, but also and mostly, for producing food, paper, clothes, etc.  The water footprint is a way of measuring our direct and indirect water use. The water footprint is the total volume of freshwater that is used to produce the goods and services consumed by an individual or a community or produced by a given business. It takes about 1500 liters of water to produce 1 kg of wheat, but it takes 10 times more to produce 1kg of beef! Producing feed crops for livestock, slaughtering and the processing of meat, milk and other dairy products also require large quantities of water. This makes the water footprint of animal products particularly important. Fish production from rivers and, increasingly, from aquaculture contribute about 25% to the world’s fish production and aquaculture is the fastest growing food producing sector: the average annual per capita supply of fish from aquaculture has increased at an average rate of 6.6% per year between 1970 and 2008. Both fisheries and aquaculture require a certain quantity and quality of water in rivers, wetlands, lakes and estuaries and are therefore important water users. Animation on Water for Food>>

How is the global demand for food evolving? There are over 7 billion people to feed on the planet today and another 2 billion are expected to join by 2050. This means that 70% more food will be needed, up to 100% in developing countries.  Besides, with rapid urbanization and incomes increase, diets are shifting. Meat consumption in particular is expected to rise from 37 kg per person per year in 1999/2001 to 52 kg in 2050 (from 27 to 44 kg in developing countries), implying that much of the additional crop production will be used as feed for livestock production. For example, 80 percent of the additional 480 million tons of maize produced annually by 2050 would be for animal feeds, and soybean production would need to increase by a hefty 140 percent, to reach 515 million tons by 2050.  FAO News: 'A third more mouths to feed by 2050' >>

How does water scarcity affect our food security? Water scarcity already affects every continent and more than 40 percent of the people on our planet. By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world’s population could be living under water stressed conditions. The lack of water limits farmers’ ability to produce enough food to eat or earn a living. South Asia, East Asia and the Middle East for example are already close to their resources limits, and their population is still growing.  FAO Water on Water Scarcity >>

What effect does climate change have on our food security? Climate change is expected to impact both rainfed and irrigated agriculture, including feed and fodder for livestock, as well as forests and aquaculture. Severe reductions in river runoff and aquifer recharge are expected in the Mediterranean Basin and in the semi-arid areas of the Americas, Australia and Southern Africa, affecting water availability and quality in already stressed regions. High latitude areas will see an increase in their potential, whereas regions near the equator will experience more frequent and severe droughts, excessive rainfall, and floods which can destroy crops and put food production at risk. Populations who live in fragile environments and depend on agriculture for their livelihoods face an immediate and increasing risk of crop failure or loss of livestock.  FAO Water: Climate Change and Water >>

Is the competition for water increasing? With population increase and economic growth, water demands for cities and for the industry are growing much faster than those of agriculture.  In some regions, increasing competition for water is constraining both current availability of water for irrigation and further expansion of the irrigated area.  In agriculture alone, staples, livestock, inland fisheries and aquaculture, and non-food crops - including liquid biofuels – already compete for water resources. The steady increase of inland aquaculture also contributes to the competition for water resources. Increased competition for water often translates into loss of access to water for the poor and other vulnerable groups. For millions of smallholder farmers, fishers and herders, water is one of the most important factors of production: without water, they cannot make a living. FAO Water: Crop Water Information >> Hydropower, fisheries and agriculture in the Mekong River  The Mekong River has undergone rapid changes in the past years. Recent announcements of agreements between riparian countries for the construction of dams on the river have raised concerns about whether these new projects will benefit from past lessons to ensure that the economic soundness and environmental impacts of the projects will be thoroughly considered. A major challenge for the basin is to design hydropower facilities with minimum impact on fisheries. The Mekong river accounts for 17% of the world freshwater fish catch, and fish is an important part of the diets and income of populations in the basin.

How has the Green Revolution degraded our land and water  while allowing to supply more food? The Green Revolution and its three pillars - high yielding varieties, chemical inputs like fertilizer and pesticides, and irrigation – has had a very positive effect on global food production but also had negative impacts on the environment. The way water has been managed has contributed to harm the environment: groundwater depletion; degradation and contamination of land and water; forest resources, ecosystem and biodiversity losses. A quarter of the world’s lands are degraded. Many large rivers run dry during part of the year, with serious impacts on aquatic biodiversity. Large lakes and inland seas have shrunk, and half of the wetlands of Europe and North America no longer exist. The number of regions across the world that cannot satisfy the basic food needs of their growing populations is increasing, and in many of these places the impacts on the environment are beyond repair.  FAO Water: Agriculture as a Water Polluter >>

But can we produce more food with less water? The future production of food and other agricultural products will not be possible without increased efforts aiming at better using water in the fields. For a long time, progresses in agricultural production have been assessed in terms of ‘yield’, the amount of production that could be extracted from a given area of land. Now, in many places, maximizing the yield per unit of land should give way to achieving the maximum yield per unit of water used. This requires a better control and application of irrigation water, and a sharper combination of the use of rain and irrigation water, combined with good agricultural practices to ensure the highest possible productivity.  FAO Water: Crop Water Management >>

Can we re-use and recycle water in food production? Drainage water, treated wastewater, brackish and desalinated water can be used in agriculture, especially in the arid and semi-arid zones and in rapidly growing peri-urban areas. Cities’wastewaters are in fact a precious source of water and nutrients for agriculture that have to be properly managed to minimize environmental and health risks.  Utilizing residues and by-flows of the food sector rather than growing crops specifically to produce bioenergy would limit the pressure on water resources and competition with food crops. It would even increase water productivity: the same water would have produced food AND bioenergy.  Many forms of aquaculture such as cage culture, flow-through systems and integrated agri-aquaculture represent food productions systems that do not significantly increase water consumption. Recirculation of water in aquaculture can reduce water use by 90%. Animation on Water Re-Use >> Water Re-Use Flyer >>

How can we protect  this precious resource? Water pollution is a main cause of reduced water availability and can have serious impacts on the environment and on human health. Pollution stems for inappropriate industrial and agricultural practices as well as from urban waste production. In agriculture, overuse of chemical fertilizers and of pesticides leads to contamination of water bodies (rivers, lakes, underground aquifers). Intensive livestock production can also impact the quality of water resources if measures are not taken. New, more integrated approaches to food production can substantially improve the situation and limit pollution. Conservation agriculture  Conservation Agriculture is an approach to managing agro-ecosystems for improved and sustained productivity, increased profits and food security while preserving and enhancing the resource base and the environment. Conservation agriculture is characterized three linked principles, namely: Continuous minimum mechanical soil disturbance. Permanent organic soil cover. Diversification of crop species grown in sequences and/or associations.

The multiple benefits of forests for water and food security: Forests reduce the effects of floods and droughts, prevent soil erosion, landslides, desertification and salinization. Forests capture and regulate water and assure high quality water supply for domestic, agricultural, industrial and ecological needs. Eight percent of the world’s forests have soil and water conservation as their primary objective. Protection also means conservation. A good soil, well maintained, can capture much of the rainwater, and avoid surface runoff which causes erosion and the loss of soil nutrients. Conservation agriculture is a farming practice that makes best use of available water, increases the resistance of plants to droughts and at the same time contributes to improving both the quantity and quality of groundwater and rivers.  Management of watersheds and the protection of water sources are also important. Forests can play an important role in protecting water resources. UN-Water Factsheet on Water Quality >>

How can we prepare for climate changes and natural disasters? Adapting water management policies and practices to climate change and other natural disasters reduces the risk of these phenomena. Improved water harvesting and retention (such as pools, dams, pits, retaining ridges, etc.), supplementary irrigation for rainfed crops, highly efficient irrigation systems and best practices are fundamental for addressing increasing irregularity of rainfalls, and increasing water productivity and food production. A particular saving potential exists for irrigated rice, which is currently flood irrigated leading to very high water use and at the same time to high greenhouse gas emissions.

In Africa, where only 4% of cropland is irrigated, small-scale supplementary irrigation with rainwater harvesting provides a great potential for securing food supply, increasing yields and reducing vulnerability to erratic rainfall. Changing rice cultivation to aerobic conditions can reduce the water use by 50%, while cutting emissions and increasing yields. Proactive drought and flood management strategies minimize the devastating impacts of these events, the frequency and severity of which is expected to increase with climate change. UN-Water Factsheet on Water and Climate Change>>

Are there ways to improve the integration of different food production systems and increase water productivity? Several integrated production approaches have developed that combine best practices in sustainable land and water management, adapted to the local ecosystems. They incorporate improved soil and water management techniques in a way that intensifies production through integrated soil fertility management, improved water-use efficiency and crop diversity. Integrated rice-fish farming is also a promising option. All these approaches offer opportunities for farmers to improve productivity sustainably.  FAO Water: Water Management  and Irrigation Systems >> The multiple uses of water for improving both diets and incomes  Growing numbers of farmers, particularly in Asia, are finding that they can both increase rice yields and add a valuable source of protein and income by using the water in their rice paddies to raise fish.

Reduce food wastage  to save water  A 50% reduction of food losses & waste at the global level would save 1,350 km3 of water (for comparison, the mean annual rainfall over Spain is 350 km3; water passing Bonn in Die Rhine is around 60 km3 per eyar; the storage capacity of Lake Nasser nearly 85 km3) (Lundqvist, J., 2012.) Finally, how can we reduce the waste? Roughly 30% of the food produced worldwide – about 1.3 billion tons - is lost or wasted every year. In many developing countries, large shares of the production are lost between the farmers’ field and the market because of poor storage and transportation facilities. In developed countries, and in particular in cities, food is wasted by the consumer who is not aware of, or sensitive to, the resources needed to produce it. Diets with excessive food intake are also a source of waste and a cause of growing heath costs. A change in consumers’ attitude towards this issue is necessary: limiting the waste means reducing the water needed to produce our food.  FAO News: Cutting food  waste to feed the world >>