Xem 1-20 trên 64 kết quả Irrigation water
  • It is widely accepted that irrigation allows for the increase and stability in agrarian yields, being a necessary tool to support food supplies and necessities for certain raw materials in the world. However, irrigated agriculture is also considered the most significant fresh water consumer and one of the main causes of pollution, degradation and depletion of natural resources. These impacts are primarily related to changes in the water cycle, salinization of agricultural soils, and salinization and pollution of water resources due to the use of agrochemicals....

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  • Populations in developing countries are growing so quickly that the land and water are unable to sustain them. In most developing countries, prime farmland and fresh water are already fully utilized. Although irrigation can be employed to bring land in arid areas into production, it often leads to salinization. In some countries, the amount of newly irrigated land is equalled by salinized irrigated land going out of production. Moreover, irrigation water is often drawn from river basins or aquifers shared by several countries, and friction over its use is common....

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  • Self-priming Jet pumps manufactured in stainless steel AISI 304, suitable for water supply, domestic pressure boosting and small irrigation systems, pool and tank emptying and general clean water pumping. Maximum working pressure: 6 bar • Maximum liquid temperature: 35°C according EN 60335-2-41 for domestic uses 45°C for other uses

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  • The Mekong River Delta (MD), the most downstream part of the Mekong river, is known as the biggest "rice bowl" of Vietnam. Currently, 2.4 million ha are used for agriculture. During the rainy season part of the Delta is flooded. Along the 600 kmcoast, the sea tide strongly influences the water quality by sea water intrusion. In addition, an area of 2-million ha is covered by acid sulfate soils. Also, the MD is very densely populated with intense associated water pollution.

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  • Mekong River, the 11th largest river in the world, is the main water source for irrigation, fishery, and domestic use… In short, the living of the whole population in the Mekong Delta (MD) is depending and will be depended on this resource. The MD of Vietnam is located at the most downstream part of the Mekong river basin. With a population of 17 million inhabitants living in 4 million hectares of land, the MD has great potentials for agricultural production. The MD is the most important agricultural production region for the whole country.

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  • Mekong river, especially in Southern Vietnam, lowest part of the Mekong River Basin. While most of Vietnamese farmers in MD use water from the rivers and canals for their daily drinking, irrigation, domestic use, etc., effects of water environment to human life is more crucial. Vise visa, impacts of human activities to water environment are also considered to ensure the sustainable development of the MD.

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  • As a matter of fact in some countries, mainly in India, groundwater development is much more important than surface water irrigation (Mukherji et al. 2009). While rainfed crops depend only on meteorological conditions, irrigated crops depend both on rain regimes and water supply. The combination of these regimes and the interdependencies between international commodity markets and domestic production create opportunities to ensure that water is allocated to the most valuable ends.

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  • Non-point source controls washed off fields is the largest source of agricultural pollution in the United States. Farmers may utilize to reduce runoff flows and retain soil on their fields. Common techniques include contour plowing, crop mulching, crop rotation, planting perennial crops and installing riparian buffers. Nutrients nitrogen and phosphorus are typically applied to farmland as commercial fertilizer; animal manure; or spraying of municipal or industrial waste water (effluent) or sludge.

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  • Water conservation encompasses the policies, strategies and activities to manage fresh water as a sustainable resource to protect the water environment and to meet current and future human demand. Population, household size and growth and affluence all affect how much water is used. Factors such as climate change will increase pressures on natural water resources especially in manufacturing and agricultural irrigation.

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  • (Đánh giá chất lượng nước và các giải pháp tích hợp cho quản lý tài nguyên nước bền vững trên địa bàn tỉnh Sóc Trăng) This work aims to assess water resources for domestic and irrigation purposes in coastal areas of Soc Trang province- one of the most vulnerable regions in the Mekong Delta to climate change and sea level rise, especially along the coastal areas where is severely affecting by seawater intrusion.

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  • The Mekong River Delta (MD) in Vietnam has an area of 4 million hectares. The economical production in this region is highly dependent on water from the river and canal system. More than two-third of 17 million inhabitants of the MD live in rural areas and depend totally on the water resources for rice, upland crop irrigation, aquaculture of fish and shrimp, domestic drinking and industrial water supply and for transportation on rivers and canals

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  • The Mekong delta (MD), the most downstream part of the Mekong river (See figure 1), is known as the biggest "rice bowl" of Vietnam. The Delta has a population of 17 million inhabitants living in 4 million hectares of land. All the people living in the Delta have to depend totally on the water resources, mainly the surface water, for domestic drinking, crop irrigating, fish-shrimp raising, goods transporating and industrial producing.

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  • Sodium concentration in irrigation water replaces calcium by the process of Base Exchange, therefore reduces soil permeability. Furthermore, excess salinity in groundwater used for irrigation decreased plants osmotic activity and interfere water absorption and nutrients from the soil. Nearly 5% of groundwater from the study site exceeds the desirable limit (1000 mg L-1) of chloride. The natural source of chloride is due to the weathering of phosphate mineral apatite present in granites.

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  • Các thuật ngữ liên quan đến các loại nước Raw water: Nước thô Canal: Kênh (sông đào) (Dòng nước nhân tạo thường được xây dựng để nối sông, hồ hoặc biển, và thường có kích cỡ phù hợp cho vận tải thuỷ; phần lớn các kênh có lưu lượng thấp và đặc tính trộn lẫn thấp).

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  • Research Reports IWMI’s mission is to improve the management of land and water resources for food, livelihoods and environment. In serving this mission, IWMI concentrates on the integration of policies, technologies and management systems to achieve workable solutions to real problems—practical, relevant results in the field of irrigation and water and land resources.

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  • In the experiments, the chlorophyll fluorescence was measured under steady-state conditions, in 20 min predarkened intact leaves, and we have employed as the excitation source, a blue LED at 405 nm with 10 nm of bandwidth and delivering a maximum power of 2.2 mW. The choice relies upon the fact that its wavelength resides within the main absorption band of Chl a, producing much higher fluorescence emission intensity.

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  • Irrigation-farming and dry-farming are both systems of agriculture devised for the reclamation of countries that ordinarily receive an annual rainfall of twenty inches or less. Irrigation-farming cannot of itself reclaim the arid regions of the world, for the available water supply of arid countries when it shall have been conserved in the best possible way cannot be made to irrigate more than one fifth of the thirsty land.

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  • The combination of fragile, often steeply sloped terrain, low fertility, crops unsuited to the terrain, lack of external inputs, and “slash-and-burn” farming techniques results in serious and rapid soil exhaustion, erosion and sedimentation 3 [see Annex 1]. In these cases, cleared land has to be abandoned after only a few cropping seasons, triggering a need for further forest land conversion farther out on the agricultural frontier.

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  • Variation in precipitation will also affect the salinity levels of surface water. Increased rainfall or runoff will likely reduce salinity levels, especially in winter, while lower precipitation levels and higher temperatures during summertime could increase salinity levels (Jacobs et al. 2001). As a result, semi- arid regions that suffer from decreasing runoff will be greatly impacted by salinization (Jacobs et al. 2001).

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  • In his History of the World Roberts (1990:908), commenting on a world population exceeding 5 billion persons, writes: ‘Though it had taken at least 50000 years for Homo sapiens to increase to 1000 millions (a figure reached in 1840 or so) the last 1000 million of his species took only 15 years to be added to a total growing more and more rapidly’. More recently it is estimated that the world population reached 6 billion in October 1999 and that the increase from 5 to 6 billion, huge army of the world’s desires, took place in a mere 12 years (Schoon 1999)....

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