Aiming respectively at the two problems in desertiflcation areas, namely water shortage and serious soil erosion, the polymer materials for combating desertiflcation may be classified as water absorbing-retaining poly...Aiming respectively at the two problems in desertiflcation areas, namely water shortage and serious soil erosion, the polymer materials for combating desertiflcation may be classified as water absorbing-retaining polymers (WARPs) and sandy soil stabilizing polymers (SSSPs). Their further classifications and current researcfl situations were introduced. It is suggested that the major hindrancefor their wide appHcation is the high cost. The authors' newest research resuits on cutting cost and enhancing ef...展开更多
Distribution of desertification climate types in China was analyzed using Thornthwaite's method on calculating potential evapotranspiration (PE), according to the definition provided by the United Nations Conventi...Distribution of desertification climate types in China was analyzed using Thornthwaite's method on calculating potential evapotranspiration (PE), according to the definition provided by the United Nations Convention, by employing meteorological records from 1864 stations in China. The annual PE and the humidity indices were calculated for every station, based on which a distribution map of HI was constructed. The potential range of desertification in China was obtained for the first time, about 3.32 million km2 and makes up about 34.6 percent of the country. The distribution map of HI was compared with the vegetation map of China and the precipitation map of China respectively. In eastern and northern China, the distribution of climate types is basically acceptable, but for QinghaiTibetan Plateau, where Thornthwaite's method on calculating PE is not quite suitable, the isopleths are deviated to the northern side and the potential range of desertification is smaller than expected.展开更多
基金Supported by the Fund of National High-tech R&D Program (Project No 2001AA242043)
文摘Aiming respectively at the two problems in desertiflcation areas, namely water shortage and serious soil erosion, the polymer materials for combating desertiflcation may be classified as water absorbing-retaining polymers (WARPs) and sandy soil stabilizing polymers (SSSPs). Their further classifications and current researcfl situations were introduced. It is suggested that the major hindrancefor their wide appHcation is the high cost. The authors' newest research resuits on cutting cost and enhancing ef...
文摘Distribution of desertification climate types in China was analyzed using Thornthwaite's method on calculating potential evapotranspiration (PE), according to the definition provided by the United Nations Convention, by employing meteorological records from 1864 stations in China. The annual PE and the humidity indices were calculated for every station, based on which a distribution map of HI was constructed. The potential range of desertification in China was obtained for the first time, about 3.32 million km2 and makes up about 34.6 percent of the country. The distribution map of HI was compared with the vegetation map of China and the precipitation map of China respectively. In eastern and northern China, the distribution of climate types is basically acceptable, but for QinghaiTibetan Plateau, where Thornthwaite's method on calculating PE is not quite suitable, the isopleths are deviated to the northern side and the potential range of desertification is smaller than expected.
