农业用水
2010-1
科学出版社
Jiqing Song，Wenbo Bai，Maosong Li 著
202
Water resource is one of the most important natural resources that mankind depends on for survival and development， and one of the controlling factors of the ecology and environment. Global water use has been growing at more than twice the rate of population growth in the last century. Moreover， the water scarcity situation is being exacerbated by climate change， especially in the driest areas of the world. Agriculture consumes about 70 percent of all freshwater withdrawn and up to 95 percent in several developing countries. To tackle water scarcity even as the demand for food increases， we must support initiatives to improve water conservation and delivery systems， protect the earths ecosystems， conserve rain-fed moisture and use water for food production more efficiently， or produce more food with proportionately less water. Coping with water scarcity requires addressing a range of issues， not all of them directly linked to agricu-lture. They range from protection of the environment and global warming to fair pricing of water services and equitable distribution of water .for irrigation， industry and household use. This is why not only the agriculture sector， but everyone， international organizations， governments and local communities must share the responsibility. As this situation， the international organization， company and Chinese government are dedicated to the exchange of recent advances in development of water-saving chemical materials， agricultural application technology and eco-envi- ronmental safety. The International Symposium on Water in Agriculture and Forestry： Challenges， Technological Solutions and Innovations aims to offer opportunities for participants to interact， present their most recent findings and to hold discussions with their colleagues from other countries， and provide a platform for potential future collaborations. The organizers of the International Symposium includedl Institute of Environment and Sustainable Development in Agriculture （IEDA）， Chinese Academy of Agricultural Science （CAAS）， Tottori
Global water use has been growing at more than twice the rate of population growth in the last century. The scarcity, of water resources and water pollution restrict the sustainable development of the economy and society all over the world. Agriculture is the major consnmer of water worldwide. Water-saving agriculture is an urgent need for sustainable development. Water in Agriculture: Challenges,Technological Solutions & Innovations is based on the invited keynotes and contributory papers presented at the International Symposium on Water in Agriculture and Forestry held during 21-24, October 2008 in Beijing, China. Including the latest research developments made by 18 research groups worldwide and leading experts in the field, this volume provides state-of the art knowledge on。
PrefaceSection Ⅰ Water Resources and Water Crisis in China:an Overview The Connotation and Extension of Agricultural Water Resources Security The Shortage, Pollution and Management of China's Water ResourcesSection Ⅱ Application of Chemical Water-saving Materials in Agriculture Degraded Lands and Hydrogels: From an Ecological Catastrophe to Economical Profit The Principle Mechanisms of Action and the Application of Super Absorbent Polymers in Agricultural ProductionSection Ⅲ New Materials and New Technologies Preparation and Characterization of Nanocomposite Films from Chitin Whisker and Waterborne Poly (ester-urethane) with or without UltraSonification Treatment Effects of Ultra-Sonification Assisting Polyethylene Glycol Pre-Treatment on the Crystallinity and Accessibility of Cellulose FiberSection Ⅳ The Effect of Water-saving Chemical Materials in Agriculture & Forestry Water Potential Preliminary Study of Superabsorbents and Mineral/polymer Hybrid Superabsorbents The Effects of Super-absorbent Polymers on the Ponding Infiltration Characteristics of Soil Water Effect of a Water-Retaining Agent on Photosynthesis and Water Utilization at Different Growth Stages of Winter Wheat Effects of PAM on Aggregate Distributions and Stabilities of Three Types of Soils in the Loess Plateau, China Analysis of the Economically Efficient Quantity of a Water Retention Agent in Agricultural Production and Factors Affecting Demand The Effect of Super Absorbent Polymers on the Growth and Yield Performance of Cotton in Xinjiang, ChinaSection Ⅴ Related Studies on Water Use & Drought Adaptive Mechanisms for Drought and the Improvement of Crop Yields in the Arid Xinjiang Area of China Ecophysiological Strategies for Improving Wheat Water Use in Semi-Arid China Divisions of seasonal droughts in hilly areas of southern China Streamfiow Simulation over the Yellow River Basin using Two Different Resolution of the LRM with RIEMSContributing Authors
With a rapidly growing economy and burgeoning populations， the countrys scarce water resources are seriously affected by pollution from the vast dis- charges of industrial and domestic wastewater， indiscriminate solid waste disposal， and runoff from an agricultural sector characterized by the excessive use of ferti-lizer and pesticides and by large-scale livestock breeding. Nowadays， most of thewater bodies in China are polluted， and some are heavily polluted. Surface andgroundwater pollution now represents a very large problem， both for publichealth and for the environment. The total wastewater discharges have steadily risen， being 53. 7 billion tons in2006， with COD discharges and NH3-N discharges amounting to 14.28 millionand 1.41 milliotl tons， respectively （MEP， 2007）. It was not until 2007 that therising trend of water pollution discharges began to show signs of reversing， as thetotal 2007 COD discharges were reported to be 3.14% less than for 2006. In2003，38. 1% of Chinas river waters were considered to be polluted， up from 33%just one decade earlier. More than 75% of the water in the rivers flowing throughChinas urban areas is unsuitable for drinking or fishing. Only 6 of Chinas 27largest cities have a drinking water supply that meets the State standards. Manyurban river sections， and some large freshwater lakes， are so polluted that theycannot even be used for irrigation （Economy， 2004）. According to The State Environmental Protection Administrations （SEPA）annual report （EAI， 2003）， over 70% of the water in five of the seven major riversystems， the Huai， Songhua， Hai， Yellow and Liao， was grade IV or worse， i. e.， it could not meet any designated beneficial uses. For the Hai and Huai rivers， thisamount was 80. Even the majestic Yangtze river suffered a deep decline inwater quality， more than doubling the percentage of its water that was notsuitable for human contact to 48. 5 % in 2002 （Economy， 2004）. Over the past decade， the rapid growth in populations and industrial activitieshas also been accompanied by a rapid rise in the level of pollution in Chinaswaterways. In terms of the source of water pollution， 50% of the water pollutionis caused by industrial and municipal wastewater discharges and by the leachingof solid waste; the remaining 50% is caused by non-point sources （in ruralareas）， including nutrient runoff， pesticides， and emissions from intensive livestockproduction.
