COUNTERMEASURES ACCOUNTING FOR AGRICULTURAL WATER SHORTAGE

Yu Fuliang and Luo Lin

Department of Water Resources, IWHR

P.O. Box 366, Beijing 100044, China

Tel: +86-10-68415522 ext. 3513, Fax: +86-10-68483367

E-mail: xxm@iwhr.com 

Abstract: China’s agriculture relies far more heavily on irrigation than other countries because of its special natural condition. With rapid increase in population, the raising of people’s living standards, continual decrease in cultivated land, higher and higher water demand will be resulted from the agriculture and rural economy development. Based on the analysis of water crisis facing by the agriculture sustainable development, social practice, as well as scientific and technologic improvement, it can be concluded that the ultimate countermeasures accounting for water crisis facing by the sustainable development of China’s agriculture is the implementation of high efficient use of agricultural water use. The raise of water use efficiency and water production efficiency is the key strategy related to the subsistence and development of 1.6 billion Chinese in the 21^st century. 

Keywords: water crisis, agricultural water resources, high efficient water use, countermeasures

1    WATER CRISIS FACING BY THE SUSTAINABLE DEVELOPMENT OF CHINA’S AGRICULTURE

1.1    Water crisis limits the agriculture and national economy sustainable development

Since the founding of the People’s Republic of China, a large amount of water conservancy infrastructure have been constructed and strongly encouraged the development of the industry and agriculture and urban construction, resisted flood, protected environment, and obviously raised the people’s living standards. With the increase in population and rapid development of the society and economy, the water supply obviously cannot meet the water demand and resulted in water shortage. According to statistics, drought disaster bring with more serious affection than flood disaster. Therefore, a critical problem facing by the development of China’s society and economy is how to satisfy the water demand of society and economy.

Water shortage resulted in: (1) The production from rain-fed land which area is more than 50% of total cultivated area in China has to rely on climate, and is low and unstable. Consequently, the agricultural development has badly been limited. (2) The water shortage resulted from water pollution is also remarkable. (3) In the northern part of China, a series of the ecological and environmental problems occurred and day and day worsened, including drying up of rivers, bad overdraft of groundwater, decline of groundwater table in broad area, and so on. (4) Large amounts of wastewater and sewage without treatment have been directly and indirectly used for irrigation, specially in the northern part of China, and gradually become an important component part of agricultural water use. The use of wastewater and sewage without treatment resulted in the pollution of soil water in farmland and groundwater and the excess content of pollutants in agricultural products which are harmful to the people’s health. This kind of harm is very severe.

Except for the water shortage and the water environmental problem, China’s water crisis still includes the frequent flood disaster and the low capability of resisting natural disasters. Flood disaster is still a serious danger to the sustainable development of China’s agriculture.

1.2    Water crisis in the 21^st century in china

The water demand and supply in the 21^st century in China will face: (1) Due to too fast increase in water demand and limited increase in water supply, the lag between demand and supply will further be widened; (2) Because of the existing water source drying up, water projects aging and inadequate maintenance, and so on, the water supply sharp decline; (3) In the northern part of China, the available water supply obviously decrease with deep development of water resources and the water consumption increase in river basin; (4) The warmer and warmer climate may aggravate water crisis; (5) With industrial and domestic     water use increase, water pollution will more and more seriously threaten water supply and safety of water use; (6) People don’t fully understand the seriousness of water crisis, thereby water projects aren’t enough and management is backward. Water supply lag water demand with extravagant water use. The low water use efficiency and water production efficiency further worsen the water crisis.

The 21^st century will be an era of the great development of economy, and an era which China’s population will reach the peak of 1.6 billion. Water is an important constraining factor for the economy development. If the problem of water shortage cannot be resolved, the sustainable development of society and economy must be seriously imperiled.

Moreover, the water crisis mainly affect the agriculture development by: (1) Competition for water among regions, between industry and agriculture, between urban and rural, will continue for a long time and be more serious. (2) Competition for water between agriculture and environment will stand out, specially in the northern part of China. (3) With the development of economy and the raise of people’s living standards, the water demand by other agriculture, including forestry, animal husbandry, fishery and subsidiary, must extremely increase. Accordingly, competition for water within agriculture sector will be more outstanding.

2    WATER DEMAND OF NATIONAL ECONOMY DEVELOPMENT

2.1    Status of water use

The rapid, continuous economy development and improvement of society promote the swift increase of water use. In amount of water use, the total water use increased by about one fourth, from 443.7 B m³ in 1980 to 559.1 B m³ in 1999. But there were different growth rates in different sectors. The percentage agricultural water use in total water use decreased from 83.4% to 69.2%, while the percentage of industrial water use increased from 10.3% to 20.7% and the percentage of domestic water use increased from 6.3% to 10.1%. This change indicated the structure of water use was profoundly transforming. The statistics of water use in 1980 and 1999 are shown in Table 1.

Table 1  Water use in 1980 and 1999 in China

Note: water use by theromal power plants included in industrial water use; water use by commercial vegetables included in urban domestic water use; water use by domestic livestock included in rural domestic water use.

2.2    The development of irrigation area and agricultural water use

Rural economy rapidly developed and grain production steady increased, but the increment of agricultural water use was limited. Though the actual irrigation water use is affected by many factors including yearly hydrologic and meteorologic conditions, the general trend of water use in the whole country still can be concluded. The decrease of irrigation water use was mainly due to effective agricultural water saving and shortage of water supply for agriculture in water scarcity regions. With the development and popularization of agricultural water saving, the efficiency of agricultural water use is being raised. The actual irrigation area increased by about 8,200 thousand hm² from 1980 to 1999, but the change of irrigation water use was tiny. In general, the average water use per hm² decreased from 8,750 m³ in 1980 to 7,270 m³ in 1999. The water use of per unit area decreased by 17%. These agricultural statistics are shown in Table 2. The water use by forest, herd and fishery fast increased while irrigation water use decreasing. Sequentially, the water demand by ecological environment had better been met.

Table 2  Irrigation area and water use

2.3    Water demand

Based on the analysis of the relationship between water resources and the sustainable development of national economy, the characteristic of water resources, factors of water resources rational allocation supporting the sustainable development, status of water use and supply, as well as the existing problems, the water demand before the mid-21^st century have been predicted. The prediction on water demand by industry, agriculture and domesticity in different target years are shown in Table 3.

Table 3  Prediction on water demand (B m³)

Table 3 indicates the basic increasing trend of water use: faster increasing of industrial and domestic water use, little increasing of agricultural water use, steady growth of proportion of industrial and domestic water use in total water use, decrease of proportion of agricultural water use. However, because of natural condition, the agricultural development in China has to rely on irrigation. So the proportion of irrigation water use in total national economy water use always is highest among the sectors.

According to the status and the development trend, three main problems, such as flood disaster, water shortage and water environment worsen, especially the water shortage will more and more heavily limit the development of agriculture, society and economy. How to resolve the contradiction between the sustainable development of agriculture and water supply is one of the focus related to the sustainable development of society and economy.

3    COUNTERMEASURES ACCOUNTING FOR AGRICULTURAL WATER CRISIS

The agriculture development in China relies more and more heavily on water sources. Based on the analysis of the existing problems and the improvement of society, science and technology, rational development and high efficient use of agricultural water resources is unique strategy accounting for water crisis involving in grain supply to 1.6 billion Chinese in the mid-21^st century. Water crisis is affected by many factors. The following countermeasures should be taken:

3.1    Energetically increasing input to the construction of new water source projects

While the development of water saving in agriculture, the input to the construction of water conservancy infrastructure should be increased so as to develop various water source for irrigation. Some important water projects for the development of national economy should be constructed to change the status of water shortage in the north part of China and the coastal regions, to improve the production condition of the important production bases of grain and cotton, and to promote the agriculture development. Developing rain irrigation is very important not only to the agriculture development on rain-fed land, but also to the high efficient use of irrigation water and the relaxation of contradiction between the demand and the supply. The utilization degree of rain and flood during flood season should be raised by structure and non-structure measures in order to combine flood control with generating benefit, i.e. utilizing resources while controlling disaster. It will play an outstanding role in relaxation of water crisis and flood disaster. The treatment and reuse of wastewater and low quality water will not only relax the water crisis in irrigation, but also improve and protect the ecological environment.

3.2    Vigorously developing high efficient use of agricultural water use

At present, the production efficiency of irrigation water is still less than 40%, accordingly which decrease the utilization efficiency of rain and irrigation water and worsen the water crisis. The water production efficiency can be improved by taking synthesis agricultural measures to decrease crop’s invalid water consumption. These agricultural measures include: planting the crops and breed with the characteristics of low water consumption and high production; improving utilization ratio of soil water and protecting soil moisture; high efficient allocation and control of water and fertilizer; covering planting; improving crop’s drought resistance and water utilization efficiency by chemical measures.

The development of high efficient use of agricultural water use relies not only on technology, but also on the following sufficient studies: studying and establishing the strategy and target of the development of agricultural water saving; study on the basic gist putting forward the general target and task of agricultural water saving; for different stage and region, study on the requirement on agricultural water saving by national economy development, the national economic base supporting the development of agricultural water saving, farmer’s income, investment ability and interesting, as well as the development strategy and technologic principle; for different stage, study on the mechanism prompting agricultural water saving and its change and control measures; study on the stage of industrialization of agricultural water saving.

The development of high efficient use of agricultural water use must be sustainable and accord with the following three criterions: firstly, sustainablity—can effectively protect, rationally and high efficiently utilize water resources and make the utilization sustainable; Secondly, efficiency—can markedly raise economic efficiency, including water saving, production increase, land saving, energy saving, ecological environmental benefit, profit of non-agricultural capital input, and so on; Finally, high scientific and technological characteristic—should be scientific and technologic and can fully meet the requirement on high efficient use of agricultural water use at different development stage.

High Efficient use of agricultural water use is the foundation supporting the sustainable development of agricultural and the sustainable utilization of water resources.

3.3    Energetically improving and protecting the agricultural ecological environment

The simple improvement with protection target should be transferred to the improvement with exploitation target in order to combine tightly ecological benefit with economic benefit. The exploitation should be combined with and promotes the improvement. Strengthening the construction of water conservancy infrastructure on farmland in order to raise the farmland’s ability of resisting water-logging and saline disasters, and rationally utilize the water resources. The pollution of the agricultural water resources should be effectively prevented and improved by the rational and effective use of fertilizer and bad water source.

3.4    Intensifying the management for high efficient use of agricultural water use

It is recognized in the World that 50% of potential of irrigation water saving is from the improvement of management. There is a very big gap in management plane of water resources between China and the developed countries. Firstly, the policies and codes prompting high efficient use of water resources are not perfect. There is short of mechanism and management measures encouraging high efficient use of agricultural water use. Secondly, the technical system supporting high efficient use of water resources has not been established. The potential of water resources far has not been fully developed. Thirdly, there is short of engineering measure which can support the improvement of management, because of the low project standards of many agricultural water projects. Therefore, to resolve the water crisis, the water management must be changed from an extensive pattern to an intensive pattern, including: (1) establishing the management system supporting rational and high efficient use of water resources to make the unified management of water resources available. (2) establishing the price system prompting rational use of water resources to form a sound market mechanism for the management of water use. (3) establishing the guarantee system prompting high efficient use of agricultural water use, including investment mechanism.

3.5   Strengthening scientific study and research work, specially on the development of series products of high efficient water use

With the contradiction between the demand and the supply is day and day outstanding and the national economy is developing, many technical problems related to the high efficient water use are waiting for resolving and new technical problems appear in succession. All the problems need to be profoundly studied. The technical integration and innovate system supporting the high efficient use of agricultural water use should be established. The science and education should benefit the development of water resources. The development of series products of high efficient water use should be strengthened. The efficiency of water use should be raised.

3.6    Reforming the mechanism of water management in irrigation districts

The technical reform and management system reform of irrigation districts must be pressed on to reach the target of high efficient use of water resources and solidify the agricultural production on irrigated area on which the crop’s production account for third-fourth of the entire country. The technical reform of irrigation districts is basis of high efficient water use, and the management system reform of irrigation districts is its assurance. The management system reform of irrigation districts will benefit not only for the exertion and increase of value of state’s capital, but also for the sustainable development of irrigation agriculture and high efficient water use, even for food security. So it is one of the important measures accounting for the water crisis, and is also a key component of the prosecution and management system reform in agriculture and rural. This reform should be in line with the development of market agriculture and integration of prosecution to be one part of the socialism market economy.

4    CONCLUSION

Because of the limit of natural condition, immense requirement of the society and economy development, weak economic base, and so on, the sustainable development of agriculture is facing severe water crisis. With the population increase, people’s living standard raise and cultivated land decrease, the press on cultivated land, specially on irrigated cultivated land, will be more and more heavy. Water will dominate the fortune of China’s agriculture and the survival and development of 1.6 billion Chinese in the 21^st century.

Based on the analysis of water crisis, social practice and the advancement of science and technology, the essential measure accounting for the water crisis faced by the sustainable development of agriculture is high efficient use of agricultural water use. The raise of water use efficiency and water production efficiency is key strategic measure related to the survival and development of 1.6 billion Chinese in the 21^st century.

The development of agriculture and water is a huge system engineering. The water crisis must be roundly resolved from system viewpoint. It should be realized the water’s complexity. Don’t keep eyes only on water. The problem of water resources should be roundly resolved from system viewpoint and by means of carrying out the comprehensive prevention and cure strategy, to reach effect which is more than the addition of single strategy’s effect. The utilization efficiency and production efficiency of water resources must be raised by means of system engineering and carrying out the comprehensive measures including water projects, agricultural biologic measure, modern management technology, information engineering technology and meteorology, to basically resolve the contradiction between water supply and demand, and to support the rapid development of society and economy in China in the 21^st century.