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Over the years, the Hong Kong Observatory has carried out scientific studies to evaluate the observed climate trends and project the future climate in Hong Kong. Analysis of the meteorological observations at the observatory's headquarters in Tsim Sha Tsui since 1885 reveals that the temperature rise in Hong Kong during the past 124 years is in accord with the global rising trend. The accelerated rising trend in the mean temperature in last few decades may be attributed to the anthropogenic influences, especially urbanization. A similar increasing trend is also observed for rainfall. Other observations such as increasing cloud amount and decreasing total global solar radiation are all consistent with the global trend. Studies of past occurrences of extreme temperature and rainfall have also been carried out. The results indicate that cold episodes have become rarer while very hot days and heavy rain events are becoming more frequent. The observatory also makes use of the data from the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) and employs statistical downscaling techniques to carry out projections of temperature and precipitation in the 21st century. It is found that the rise in temperature in Hong Kong will be slightly higher than the global mean in the 21st century. The annual rainfall in Hong Kong is also expected to rise by the end of the 21st century, so is its year-to-year variability. 相似文献
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Huaibei area is an important iron-copper metallogenic area in northern Anhui Province. In order to summarize the metallogenic series and regularity of skarn-type deposits systematically in this area, based on recent prospecting results and the diagenesis and metallogenic chronology, the authors systematically investigated the geological characteristics and metallogenic conditions of the known deposits and divided thern into three metallogenic series. They are skarn-type iron-copper-gold metallogenic series related to high-K calc-alkali intrusive rocks, skarn-type iron-gypsum metallogenic series related to high-K calc-alkaline intrusive rocks and skarn-type iron-light rare earth metallogenic series related to monzogranite. Then the geological characteristics and metallogenic regularity of four typical deposits were discussed respectively. The results show that the deposit formation can be divided into two stages in this area, and the metallogenic space is controlled by deep faults, arc structures and magmatic belts. Finally, the regional metallogenic models of Qianchang type, Yangqiaozi type and Wangchang type iron polymetallic deposits in the early stage of Early Cretaceous and Qiganlou type iron-light rare earth deposits in the late stage of Early Cretaceous were established. 相似文献
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