| In the21st century, the serious and frequent droughts have become one of the most severe natural disasters in our world. Compared with other natural disasters, droughts occur frequently, have the longest duration and have the greatest impact area. Droughts make serious impact on human society and the sustainable growth in economic, and threaten the natural environment of human to live in. Coping with the droughts, it is very necessary and significant for us to make countermeasures for fighting against regional droughts by evaluating the regional drought level and analyzing the spatial and temporal distribution of droughts.In this paper, based on the31national first-class and second-class meteorological stations from1965to2011daily observations temperature, precipitate and relative humidity, make comprehensive use of multivariate statistical analysis, the knowledge and methods of Geographic Information Systems and Remote Sensing, in studying the temporal and spatial distribution characteristics of the main impact factor leading to drought. Then we can analyze the spatial and temporal characteristics of drought, happening in Yunnan province. At the same time, considering the time series data about MODIS-NDVI in February2002-December2011, we analyzed the correlation ship between MODIS-NDVI and climatic factors, to establish the regression equation between NDVI and climate factors, discussing the method of monitoring droughts happening in Yunnan province by using Remote Sensing.The results of the study show that:(1) Nearly47years, from1965to2011, the rainfall precipitation in Yunnan province showed an upward trend, On the contrary, the droughts has a downtrend. Yunnan regions have obvious inter annual fluctuations between season average precipitation.47a prevailing in total season drought appears30times, mainly in winter and spring. Drought mainly occurs in January, February, march, November and December, and the drought happened in December and January most times.(2) The interpolation analysis about the average annual precipitation of Yunnan province in nearly47years shows, the geographical distribution of precipitate is uneven, appearing the trend that the southwest has a high rainfall precipitation, on the contrary, the rainfall precipitation in northwest and northeast is low. In Yunnan province, drought occurs easily in the northeast and northwest, and the regions in which drought disaster occurs most frequently, are Dali, lijiang, the northwest of Yunnan province, and then followed by Wenshan, Qujing, Zhaotong, Kunming, Chuxiong which in the eastern and northern of Yunnan province.(3) Statistical analysis shows that the correlation between rainfall and NDVI is very significant, verifying the possibility about NDVI reflecting changes in rainfall and the feasibility in monitoring drought. We can Use the same degree of vegetation index difference to reflect the distribution of the drought, achieving the purposes of drought monitoring to a certain degree.(4) Analysis of the characteristics of drought in Yunnan Province, and puts forward the countermeasure. |
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