How to save water resources abroad

I. Basic situation of agricultural water resources in Egypt

Egypt's agricultural and economic development is mainly concentrated in the Nile Valley and the Nile Delta, which account for 4% of the country's land area, and about 96% of the country's population lives here.

Egypt is an arid country. There is little rain in the whole territory, with a total rainfall of 65.438+0.5 billion m3, and the vast area has a tropical desert climate. There is a little more rain in the northern Mediterranean coastal area, and the annual rainfall is less than 200 mm. From north to south, the rainfall drops sharply. The annual rainfall in Cairo is only 33 mm, and the annual rainfall in the area south of Cairo is almost zero. Even this rare rainfall only occurs sporadically in winter. The temperature in Egypt is relatively high, the northern coastal area is mild, the southern area is hot and dry, and the ground evaporation is extremely high. For example, the ground evaporation in Cairo is as high as 1020mm. Therefore, most of the northern Mediterranean coastal areas belong to irrigated agricultural areas, except for a few areas that can engage in rain-fed agriculture, that is, there is no agriculture without irrigation.

Agricultural water use in Egypt mainly comes from the following aspects: ① Nile water. This is the main source of water for the whole national economy of Egypt. According to the agreement reached between Egypt and the Sudanese government in history, Egypt gets 55.5 billion m3 of Nile water every year, of which about 86% (about 52 billion m3 is used for agricultural irrigation; ② Groundwater. The groundwater in the Nile valley and delta aquifer is about 4.6 billion cubic meters (shallow water) every year, and the groundwater in the deep aquifer in the desert (confined water) mainly depends on the comprehensive evaluation of pumping cost and possible disasters caused by water storage attenuation, and about 500 million cubic meters are mined every year; ③ precipitation. The available amount is less than 50% of the total rainfall; (4) Agricultural wastewater (mainly refers to backwater in farmland drainage and irrigation) and urban sewage reuse. Adopt the method of comprehensive utilization of agricultural wastewater, surface water and groundwater; It reaches 4.7 billion cubic meters every year. Municipal sewage is used for agriculture through purification, and it is currently in the stage of experiment and small-scale application, with an annual output of about 500 million cubic meters.

Due to the rapid growth of Egypt's population, from more than 20 million in the 1950s to 66 million in the late 1990s, Egypt's water demand has greatly increased, from 60 billion cubic meters in the 1960s and 1970s to 70 billion cubic meters at present. In this situation, the Egyptian government pays more and more attention to how to strengthen the management of water resources and the research and popularization of agricultural water-saving irrigation technology.

Ii. management and policies of water resources in Egypt

As Egypt is a water-deficient country, water resources management is centralized and unified. Regardless of surface water, groundwater and wastewater, the Ministry of Water Resources and Irrigation implements unified management and distribution, and implements legislative management. Egypt's water resources management legislation has a history of 30 years. At the same time, different water price policies are implemented, and agricultural water has been free; The water price of urban residents is determined according to different living areas with different incomes. High-income communities have high water prices, while low-income communities have high water prices. At present, Egypt's water resources management mainly highlights the following aspects:

The length saves water resources and reduces losses, especially the agricultural irrigation water from the main canal to the field. If the canal system is reformed and lined, it can save 4 billion cubic meters of water. In order to save water resources, the Egyptian government put forward the policy of limiting flood irrigation and rational utilization of groundwater.

2. The principle of comprehensive utilization of various water resources, Nile water (surface water), agricultural wastewater and groundwater. Urban domestic sewage, the purified part is used for agricultural irrigation, and it is planned that 20 17 sewage purification will be used for agriculture, with a capacity of 2.5 billion m3; For the exploitation of deep groundwater in the desert, 200 1 1 has formulated relevant regulations, which are limited to drinking and agriculture.

3. Let farmers who use water directly participate in water management. Since 1996, a water users' association mainly composed of farmers has been established, with representatives from agriculture, water conservancy, finance, law and other departments participating. The state entrusts the built fixed irrigation canal system in the field to the water users' association for management, and the water users' association is responsible for the training of water-saving irrigation technology and the maintenance, operation and management of the canal system, and the expenses are borne by the farmers who use irrigation water according to the area and crop distribution. The Egyptian government believes that all canal systems used for agricultural irrigation can be handed over to water users' associations except the Nile. At present, due to the high cost of maintenance, operation and management of advanced canal system, it is unbearable for farmers. In the future, with the increase of farmers' income, the level of water diversion canal system will be improved year by year.

4. Water resources quality monitoring. Water quality monitoring centers have been established in all parts of Egypt, and a monitoring network has been formed. Such as monitoring the quantity, quality and hydrogeology of various water resources to ensure more effective use of water resources.

Three. Research and popularization of agricultural water-saving irrigation technology in Egypt

Egypt's Ministry of Agriculture and Reclamation is fully responsible for the research and promotion of water-saving irrigation technology. In recent years, the Egyptian Ministry of Agriculture and Reclamation and its subordinate scientific research extension departments have mainly done the following work around agricultural water saving;

1. Carry out basic experimental research on agricultural water-saving irrigation technology. For example, the Institute of Soil, Water and Environment, which we visited, imported advanced instruments and equipment from the United States. By monitoring and studying the relationship between climate in different regions of Egypt, soil evaporation and water demand for crop growth, we can scientifically calculate the water demand of different crops and provide scientific basis for determining irrigation quota. At the same time, by comparing the water demand of different varieties of crops, we can choose the crop varieties with short growth period, less water demand and guaranteed yield and quality, and adjust the crop planting structure to achieve the purpose of water-saving irrigation. According to reports, Egypt has achieved certain research results in this research.

2. Analyze and study all kinds of water-saving irrigation equipment and technologies in the world today. The delegation learned from the Desert Research Institute that when the sprinkler irrigation technology was introduced, the newly reclaimed desert soil was specially studied in different climates (such as wind), soil infiltration depth in different areas and sprinkler irrigation pressure with different equipment, in order to find the best water-saving state of sprinkler irrigation technology. At the same time, we also know that the following six factors are generally considered when conducting such experimental studies: ① physical and chemical properties of soil; ② Movement of water in soil; ③ Climate indicators, such as temperature, humidity, wind power, etc. (4) Crops and buildings planted, and the demand for water; ⑤ Engineering facilities, such as pumps and pipelines; ⑤ Economic analysis, such as investment and benefit, farmers' acceptance, etc. The above research and experiment are necessary for the implementation of water-saving irrigation technology.

3. Introduction, development and application of water-saving irrigation technology and equipment for agricultural modernization. The introduction and development of modern water-saving irrigation technology and equipment in Egypt are undertaken by the Agricultural Engineering Research Institute of the Agricultural Research Center. From 1978 to 1979, water-saving irrigation equipment and components were imported from abroad. Through evaluation, testing and field experiments, it is determined whether they are suitable for Egypt, and the unsuitable equipment and parts are improved. Then attract foreign capital to set up factories in various places to produce these water-saving irrigation equipment components suitable for Egypt, such as various nozzles, pumps, filters, water pipes, drip irrigation and infiltration irrigation equipment. Has been developed and produced.

4. Strengthen the popularization of new water-saving irrigation technology. The research results of water-saving irrigation technology of the above-mentioned institutes will be promoted and served to farmers and farmers in this area through agricultural research stations and sub-stations located under each institute. The steps are as follows: put the research results into farms or farmers' fields for experiments or direct demonstrations, and then recommend and suggest advanced water-saving irrigation technologies to farmers and farmers by holding meetings, distributing materials, showing slides and videos, visiting field training schools, etc., and study and solve them in time according to the feedback from farmers and farmers after implementation. The specific promotion process is as follows:

Generally speaking, the application of agricultural water-saving irrigation technology in Egypt is still in its infancy, mainly focusing on the following aspects:

The first is to improve the traditional irrigation methods in agricultural areas, improve irrigation efficiency and reduce the leakage loss of irrigation water.

One of the methods is canal system reconstruction and lining, which is being vigorously promoted at present. Egypt's arable land and population are concentrated in the Nile valley and delta, which is the traditional agricultural area and grain and cotton production base in Egypt. The soil in the Nile Delta is sticky, and it is irrigated by Nile water, and flood irrigation (rice, sugarcane) and furrow irrigation (corn, cotton) are mostly used. What our delegation saw was that most irrigation canals at all levels were not rebuilt and lined. Because agricultural water in Egypt is free, and agricultural arable land is extremely scarce. Therefore, when the Egyptian government and extension departments guide farmers to lay agricultural canals, they mainly start from the perspective of saving cultivated land after laying. Because the traditional agricultural canal occupies more land, and the lining canal can save about 50% of the land because of its faster flow speed and narrower channel. At the same time, in order to promote this improvement measure, the government provides lining materials free of charge, and farmers only need to work hard (the rural labor force in Egypt is also quite cheap). Judging from the scene of canal reconstruction and canal lining that we visited in the farmland of Sakha-Kafr district of EI-Sharkia province in the northern Nile Delta, farmers are quite welcome.

The second method is to reform irrigation methods, such as changing from flood irrigation and furrow irrigation to border irrigation and pipe irrigation. From the perspective of farmers, the incentive of reform is to reduce the occupation of farmland by traditional channels, and at the same time increase crop yield by improving irrigation efficiency. From the experimental demonstration of several farms in EL-Baheira province, we can see that it is attractive for farmers to switch to pipeline irrigation for cotton fields. Although the annual cost per Fedan (1 Fedan is about 0.42 hectares) increases by 30 Egyptian pounds, at the same time, it can increase the income by 70 pounds because of the increase in output. Its pipes are imported and made in China, and can be freely connected and moved according to the size of the site, so as to adapt to the use of different site environments and reduce costs. According to the needs of crops, the diameter of water outlet and the spacing of water outlet holes are set, and the mouth is equipped with a manual switch to control the water output and time. Egypt's policy of encouraging farmers is similar to that of China. The state subsidizes building materials, sends technicians to design and guide construction, and farmers contribute labor. For crops with high economic value in traditional agricultural areas, such as gardens, vegetables, melons and fruits, the modern water-saving irrigation technology promoted by them is more diverse than that of field crops, including sprinkler irrigation, drip irrigation and infiltration irrigation.

As mentioned above, in traditional agricultural areas, crops such as grain and cotton are also planted with short growth periods and short stalks, and the planting structure is adjusted to reduce crop water demand.

Second, in the newly developed areas and the exploitation of desert groundwater, modern irrigation technology should be fully adopted by law. Make a comprehensive plan for newly developed land (mainly desert areas, because other available land has been basically developed). The new water law stipulates that only modern water-saving irrigation techniques (mainly sprinkler irrigation and drip irrigation) can be adopted, and it is forbidden to use flood irrigation on sandy soil. At present, modern water-saving irrigation technology has been implemented in 50% of the newly developed areas in Egypt. We can see that in the desert areas such as Ismailia province, there are special extension stations to study, test, demonstrate and train modern water-saving irrigation technology for farmers, and the effect is remarkable.

Four. Experience and Suggestions on Visiting Egypt

China and Egypt are both developing countries, with the common characteristics of large population, little arable land resources and water shortage. Protecting and saving water resources and popularizing agricultural water-saving irrigation technology are the common goals of the two countries. Egyptian management of water resources, experimental research and popularization of agricultural water-saving irrigation technology, and introduction and development of modern water-saving irrigation technology and equipment are all worth learning from in China. There are mainly the following three aspects:

1. The unified management and allocation of water resources is conducive to protecting and saving water resources and improving the benefit and efficiency of water resources utilization. China's water resources are managed by many departments, and the purification of deep groundwater, surface water (rivers and lakes) and shallow groundwater, urban residents' water use and urban sewage belong to three departments respectively, which leads to the difficulty in coordinating the planning of water resources management and utilization, the inconsistent statistical caliber, the unclear water resources and the inability to meet the international standards in water balance calculation.

2. It is more effective for agricultural departments to carry out experimental research and popularization of water-saving irrigation technology and introduce and develop modern water-saving irrigation technology and equipment. Because the focus of water-saving irrigation technology is through soil tillage and mulching; The breeding and structural adjustment of crop varieties, the introduction and development of agricultural machinery and water-saving irrigation equipment, and the reconstruction and construction of field canal systems all belong to the business scope of agricultural departments and are directly related to the interests of rural areas and farmers. Industrialization is carried out by the scientific research and extension department of the agricultural department, which is more conducive to serving the countryside and farmers and achieving the purpose of saving water resources and improving efficiency.

3. Formulate agricultural water-saving policies from the perspective of legislation. For example, drawing lessons from the water-saving regulations of newly opened land in Egypt, some water-saving technologies are forced to be adopted in some areas with serious water shortage, and the government gives certain subsidies or similar preferential policies for agricultural tax reduction and exemption.

4. When applying modern water-saving technologies such as pipe irrigation, sprinkler irrigation, drip irrigation and infiltration irrigation, we should adjust measures to local conditions and understand the similarities and differences of natural conditions between China and Egypt. Egypt is dominated by irrigated agriculture, similar to the Hexi Corridor agricultural area in Xinjiang and Gansu. Egypt is located in the tropics, with frost-free all year round, abundant light resources, three crops a year, and high utilization efficiency of water-saving irrigation equipment. There is no cold winter, the equipment is not easy to age, the operating cost is low and the benefit is high. In the same area of China, the natural conditions are not superior to those of Egypt, and the efficiency and benefit of water-saving irrigation equipment are lower than those of Egypt. The situation in other vast areas of China is more complicated, and it needs to be carefully studied, tested and demonstrated when it is introduced, digested and popularized. At present, drip irrigation and infiltration irrigation technology are mostly used in protected agriculture and crops with high economic benefits in China.

We must carefully raise the price of agricultural water. Some departments in our country put too much emphasis on raising the price of agricultural irrigation water to save water. So far, Egypt has implemented a free system of agricultural water, taking into account the low prices of agricultural products to meet the needs of promoting agricultural development. The same problem exists in our country. Raising the price of agricultural water must be carefully calculated, so that farmers can get reasonable income, otherwise it will increase the burden on farmers.