| Now, climate of the whole world is being unstable. On one hand, it is being warmer constantly; on the other hand, there are nature disasters frequently. The problems of climate changing, environment of world, nature disasters, disasters protecting and reducing and so on have become the focus of people, which the problem of climate unusualness is being more followed with, because it concerns with the environment changing of world directly, and it concerns with the occurrence and development of nature disasters, and it still concerns with the continuing development of society and economic of whole world. In recent 50 years, people have gradually realized in the study of climate changing that the interaction of ocean-atmosphere is an important physical process in climate system, and it has notable effect on climate changing. So that, the study of El Nino and La Nina events, which are typical because of the interaction of ocean-atmosphere becomes more important. The occurrence of El Nino and La Nina events can cause climate unusualness, and they can also take deep effect on climate of many areas in the world through distant interaction.Drought is one of the main nature disasters in Guangdong. Though the precipitation is plentiful when contrasts with other areas in china because of being in the tropics and subtropics, it is still always disturbed by drought. That is the cause of monsoon climate, geography, geology and other conditions. Now, in more than 2,300,000 ha cultivated lands, there are 24% of them easy to be affected by drought. Since our country established, drought has been occurred more and more frequently, and the economic lost because of it also more and more serious. At the same time, the precipitation and runoff are not only distributed not meanly and changed a lot yearly, but also have evident difference in area distribution, so the effect of drought on every area is not the same.Whether El Nino and La Nina events, which of big events to world climate system can affect climate of Guangdong? Whether it can affect the drought of Guangdong? How about its extent? And what about their relation? These have become hot spots to geography, atmosphere environment, agriculture and other sciences and local government. Because there was few related study before, we need to enhance the study to these problems, in order to understand the effect of El Nino and La Nina events on Guangdong and coastlands of South China accurately.This study is a part of "The research on characters of nature disasters in El Nino years and the strategy to it", which is the foundation of "Thousand, hundred and ten project" of Guangdong education department. On the base of collecting related materials and documents, we concluded the forefather' results of relation of cause between El Nino and La-Nina. Then, we classified El Nino and La-Nino systematically,and wo used statistic analysis, especially X test and condition probability to study the relation between drought in Guangdong and El Nino and La-Nina events systematically and deeply. We first analyzed their relation using historic statistic materials, then continually analyzed using precipitation materials between 1951-2003, which departed by areas and seasons. The results indicated that:1. From the analysis to the historic statistic materials of events and drought condition, the relation of drought in Guangdong with El Nino and La Nina is not close, and so it is with the intensity of El Nino and La Nina.2. Through the research of precipitation materials, in years affected by El Nino, precipitation in west and north of Guangdong has been reduced on the whole which have been good to occurrence of drought, but the precipitation of every season in east of Guangdong and the Pearl River Delta was close to other years, which were few affected. In years affected by La-Nina, precipitation in west, east and north of Guangdong has been reduced on the whole which have been good to occurrence of drought, but the precipitation of very season in the Pearl River Delta had few... |
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