Comprehensive Monitoring And Risk Assessment Of Remote Sensing Drought In Yunnan Province

With the change of global climate, drought is becoming more and more frequent, and the loss of the disaster is more serious. Yunnan Province is located in the low latitude plateau, influenced by its unique geographical environment and climate characteristics, prone to drought disaster. Drought affected the local agricultural production, restricted the economic development, and the drought became more and more serious. How to timely and accurately monitor the scope, the degree and the development trend of the drought in Yunnan Province, then analysis the mechanism of drought disaster, evaluate the drought disaster risk, to formulate the effective measures for controlling and resisting drought and reducing disaster losses. It is significance to change passive and passive adaptation for active prevention and active coping during drought resistance.This paper studies on the temporal and spatial evolution of drought and drought disaster risk in Yunnan Province. The data in February of 2001/2005/2010 are choose to be experimental data. First, according to relationship between Temperature-Vegetation Dryness Index(TVDI), Effective Precipitation and Drought index(WAP), Normalized Difference Drought Index(NDDI), Relative Moisture Index(M) and Comprehensive Loss Rate(C), constructing drought evaluation model, monitoring the temporal and spatial evolution of drought. Then social, economic and environmental indicators are selected from The Vulnerability of Disaster-breeding Environment, The Exposure of Disaster-breeding body, The Dangerousness of Disaster Factors, The Anti-disaster Ability, the weight of each index is calculated by Principal Component Analysis based on SPSS22 to construct models of The Vulnerability of Disaster-breeding Environment the disaster environment, The Exposure of Disaster-breeding body, The Dangerousness of Disaster Factors, The Anti-disaster Ability. Finally, the reference model is used to evaluate the risk of drought disaster in Yunnan province.Main research results as follows:(1)Select Temperature-Vegetation Dryness Index(TVDI), Effective Precipitation and Drought index(WAP), Normalized Difference Drought Index(NDDI), Relative Moisture Index(m) to build a comprehensive drought monitoring model in Yunnan Province。Inversion of drought condition in February of 2001, 2005 and 2010. Results show:Drought degree of 15 cities in February in 2005 in Yunnan province is lower than that in 2001 and 2010. Pu Er is the only one that the drought degree of 15 cities in February in 2005 in Yunnan province is higher than that in 2001 and 2010. And the variation range of drought in Lijiang, Pu’er, Diqing, Dehong area are large.(2)The correlation analysis between the actual precipitation and the average monthly precipitation、the actual daily temperature and the average temperature of the years, the result shows: The average temperature in February is higher than the average temperature of 53 years, and the higher the degree of drought. 53 years average monthly precipitation is larger than that of the year February, the higher the degree of drought;And taking 1℃ and 10 mm as the critical value of temperature and monthly precipitation to affect the occurrence and development of the drought. When the average temperature in February is higher than the average temperature in 53 years, and the monthly precipitation is lower than the average monthly precipitation in 53 years, the drought will be inevitable. At the site’s temperature is higher than the average temperature of 1 ℃, precipitation is less than the average annual precipitation of about 20 mm is prone to micro drought. The value of average precipitation in 53 years minus average precipitation monthly is higher than 10 mm, the average temperature is higher than the average temperature in 53 years of 1 ℃ is also prone to micro drought.(3)Selecting indexes correlation with The Vulnerability of Disaster-breeding Environment the disaster environment/The Exposure of Disaster-breeding body/ The Dangerousness of Disaster Factors/The Anti-disaster Ability construct the risk assessment model of drought disaster in Yunnan Province by Principal Component Analysis Method to evaluate the risk of drought disaster in Yunnan Province. Results show: drought disaster risk and drought distribution is the similar in Yunnan Province, drought disaster risk are mainly distributed in the central and eastern regions of Yunnan, the northwest of Yunnan Province is lowest, and the degree of drought risk in central and eastern regions has gradually enhanced trend; The center and Eastern of Yunnan is the center of The Dangerousness of Disaster Factors for expansion; The Eastern is The Vulnerability of Disaster-breeding Environment center, and gradually extends to the central and western regions; The Northern and center are in the high exposure area of The Exposure of Disaster-breeding body and there is a decreasing trend. In general, the drought resistance ability of Yunnan province in the north is higher than that in the south.(4)Analyses are conducted on the high risk area and the indexes of drought disaster risk in Yunnan Province. Results show: The value of The Anti-disaster Ability is high, and two or three indexes of The Exposure of Disaster-breeding body、 The Dangerousness of Disaster Factors 、 The Vulnerability of Disaster-breeding Environment is high,there may be a higher risk of drought disasters, such as Kunming and Qujing; The value of The Anti-disaster Ability is middle or low, the above three factors as long as there is a higher factor may result in a higher risk of drought disasters, such as Wenshan and Zhaotong. While the value of The Anti-disaster Ability is low, the risk of drought disaster is not high because of the low vulnerability of the disaster environment and the low exposure to the disaster, such as Pu’er and Xishuangbanna.