The Research Of The Historical Drought And Flood Disasters From 1322 To 2013 In Kunming

Using the data of Kunming drought and flood disasters recorded in Historical meteorological disasters in Yunnan, Chinese nearly 500 years Atlas of flood and drought distribution, The volume of Yunnan in The collection of great classics of Chinese meteorological disasters, through classification of drought and flood disasters in Kunming by historical data and operation of formula, combined with the rain data of Kunming from 2001-2013 to reconstruct drought and flood disasters grade series since the Yuan Dynasty in Kunming, analyzed regularity of outbreak in drought and flood disasters occurred in Kunming from 1322 to 2013, discussed the reasons for the occurrence of drought and flood disasters in Kunming and compared with other areas of climate change.Studies have shown that: from 1322 to 2013, drought and flood disasters in Kunming took place frequently in nearly 700 years, and the main disaster is flood.Wavelet analysis results indicate that the drought and flood in Kunming have significant periodicity, the first main period is 39 a, the second main period is 11 a, and the third main period is 4a. The nearly 700a’s drought and flood disasters in Kunming can be divided into three stages. The overall trend of Kunming in nearly 700 a between drought and flood disasters is: at first, tends to flood, then tends to dry; From2009 to 2013 five years of drought is the development of drought tendency in 1700.The continuous drought is the least continuous disaster, the continuous drought mixed flood is the most continuous disaster, the continuous disaster’s frequency is the highest in the recorded 65 a in the People’s Republic of China, the least continuous disaster’s type is in Yuan dynasty- the drought and flood disasters in Kunming has such features, frequency, period, stage, tendency and succession.The 11 years periods of sunspot activity is corresponding with the second main period of drought and flood disasters in Kunming(11a). The 2-7 years periods of ENSO is corresponding with the third main period of drought and flood disasters in Kunming(4a). There is a law from the impact of climate change on Kunming drought and flood disaster: the warm period corresponds to more drought, cold period is corresponding with more flood. Monsoon climate can control the occurrence of drought and flood disasters, there is more floods in summer and autumn, while more droughts in winter and spring; And because of the vapor transport, more floods occur in the east, south, west, more droughts in the central region, on the contrary; There is a significant positive correlation relation between the rainfall in 63 a of Kunming,since 1951 to 2013 a. Cause by mountain blocking and Karst water leakage, the droughts are easy-happening in Kunming, then Due to the plateau surface’s smooth and karst landform’s sparse vegetation and loose soil, the floods are easy-happening in Kunming. Forest has a regulatory role on precipitation and runoff, mainly for on Runoff in flood cutting and moisturizing effect, thus alleviating the drought and flood disasters- natural factors such as solar activity, ENSO, monsoon climate, climatic change, terrain, forests play a fundamental role. However, human factors play a dual role to accelerate or slow down the drought and flood disaster.The Reflection of climate change from drought and flood disasters in Kunming historical records is the same as climate change of Erhai nearly 700 years-the same stage has the same temperature and humidity change, they have the characteristic of alternating warm-dry and cold-wet, the cold-wet had a strong fluctuation in the third stage at the same time. Comparing the Reflection of climate change from drought and flood disasters in Kunming historical records with the 700 a climate change in the eastern area of China, the temperature change is consistent, but humidity is the opposite.