| Drought and flood disaster are the main meteorological disasters in our country. In recent decades, although there are a lot of manpower, material resources and financial resources into the flood control and drought relief in every year in China, while accumulating a wealth of practical experience, different degrees of drought and flood disasters still happened in different areas and the production and life activities still be affected by the drought and flood disasters. Yun-gui area is a area that drought and flood disaster happened frequently in China, as an important landform unit in our country. At the same time, it is affected by the south Asian monsoon and east Asian monsoon, and is a climate of ecological fragile area, while being one of the world’s typical low latitude Gao Yuanou. So Yun-gui area had a special geographic location. In the background of global warming, the frequency and intensity of drought and flood disaster will be bound to a respond in Yun-gui area.Based on the monthly average temperature, precipitation and other meteorological datas of48weather stations in Yun-gui area from1960to2011, this paper analyzed the characteristics of climate change of Yun-gui area, using the trend fitting, linear regression, the M-K mutation testing, wavelet analysis, spatial interpolation and Z indeT methods and so on. This paper analyzed the changes of the evolutions of the time and spacial structures of drought and flood as well as.Then this paper studied the possible years of drought and flood being happen in future,using commensurability method with the butterfly structure and commensurability structure,based on the historital years of drought and flood which had researched in the context.At last, this paper analyzed briefly the possible causes of drought and flood occurred, basing on the El Nino events and the sunpots, and put forward countermeasures and suggestions. The main conclusions are as follows:(1) The characteristics of climate change:The climate of Yun-gui area was becoming warmer and drier in recent52years. The annual average temperature of Yun-Gui area was15.93℃, and had a rising trend at a rate of0.16℃/10a, and occured a significant mutation in1993. The average for many years of the annual precipitation was813.30-813.30mm, and had a descending trend at a rate of13.26mm/10a. The average temperatures in summer, autumn and winter appear to be going up, while the precipitations appear to be descending. However, both the average temperature and precipitation had upward trends in spring. On the spatial distribution, the annual and seasonal average temperatures in recent52years were higher in the southern rather than the northern part, when there are two cryogenic centers and a major center high temperature. The rates of average temperature tendency were decreased gradually from west to east. The annual precipitations in recent52years were larger in the southern rather than the northern part. The maTimum appeared in the southwest of Yunnan Province. The trend rate of the annual precipitation were different in the east and west areas, while the west was increased and the east was decreased.(2) The general trend of drought and flood:There were different degrees of drought and flood in Yun-gui area almost every year, which had significant age features. The years of severe regional drought were7, and the years of regional drought were5, and the years of severe regional flood were5and the years of severe regional flood were12. The annual drought indeT in the1980s was largest, and the next was the first ten years before the21st century, while in the1970s and1980s the minimum. The annual flood indeT in the1970s was largest, and the next was in the1990s, while in the1980s the minimum. The annual drought indext and spring drought indext appear to be descending, while the summer and autumn appear to be increasing. The annual flood indext and spring flood indext appear to be increasing, while the summer and autumn appear to be descending. The trends of drought and flood indext in winter were not obvious. The drought may appear in every season, while flood in summer and autumn.(3)The spatial structure of drought and flood frequency:The spatial structures of annual drought and special waterlogging were patchy distribution. The frequency of annual drought in southwest of Yunnan Province was high, while in the northern of Guizhou Province was low. The frequency of annual waterlogging in northeast of Guizhou Province was high, while in the southwest of Yunnan Province was low. The spatial structures of annual special flood and drought were scattered punctate distribution.(4)The time structure and the tendency judgment of drought and flood:The years of drought and flood in Yun-gui area had good commensurabilities. The number of droughts in Yunnan province nearly52years was19. The number of floods in Yunnan province nearly52years was11. The tendency judgment of drought and flood in Yunnan Province were that the possibility of drought year will be2015and the possibility of flood year will be2014. The number of droughts in Guizhou Province nearly52years was13. The number of floods in Guizhou Province was14. The tendency judgment of drought and flood in Guizhou Province were that the possibility of drought year will be2013and the possibility of flood year will be2014. In addition, the possibility of drought year of Yunnan Province in spring will be2013, while summer be2016and autumn be2016and winter be2014. The possibility of drought year of Guizhou Province in spring will be2015, while summer be2015and autumn be2015and winter be2013.(5) The results also showed that great drought and flood disasters would appear either before the year of El Nino or after the year, as well as the year of El Nino. The drought and flood in Yun-gui area will appear possibily when sunspots were near the peak or the valley. And there must be drought and flood when the sunpots were in the peak or the valley. |
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