| Drought has been a major type of meteorological disaster and has had a profound impact on human production and life,especially on agriculture.As a large agricultural country,China has important value and significance for the past and future research on drought.In this paper,we use two different PET estimation methods to calculate PDSI drought index to analyze the difference of drought and analyze the temporal and spatial distribution characteristics of drought in China from 1948 to 2012.At the same time,we use the PDSI drought index calculated by 14 global climate models provided by CMIP5 to predict the trend of drought in China in the next 100 years.In order to further analyze the impact of drought events on China's future population development,we use the future 100-year demographic data provided by SSPs to estimate the population in China.The future drought data will be superimposed with future population data,and the number of drought-affected populations in rural areas,urban areas,and the total population will be calculated to assess drought disasters in the 21st century.The main research results are as follows:(1)The PDSI drought index calculated by Peman-Monteith and Thornthwaite showed a dry trend in humid areas and semi-arid and semi-humid areas,especially in North China.Thornthwaite calculated drought more serious than P-M,with stronger drought intensity and wider area of drought.In dry areas,both PM and Thornthwaite showed a wet trend,but the drought intensity showed an increasing trend.This indicates that there are more extreme dry events in the arid regions in the context of overall wetting,suggesting that droughts in arid regions are likely to be extreme droughts.event.It is worth noting that the P-M calculated drought intensity in Northwest China is more severe than that of Thornthwaite.(2)Based on the PDSI drought index and the ensemble average PDSI drought index calculated based on the 14 global climate models,the results showed that in the middle of the 21st century,drought trends appeared in East China,North China,and Central China,while in the late 21st century,the region showed a wet trend.The humid region has a tendency of drought in the next 100 years,the drought intensity increases and the arid area shows a clear growth trend;the semi-arid and semi-humid region shows a weak trend of drying in the next 100 years,the drought intensity shows an increasing trend,and the arid area presents Obvious growth trend.The arid regions show a weak tendency to become wet in the next 100 years,especially after the 1970s,the intensity of drought has increased,and the area of drought has also shown a clear growth trend.(3)The population of China's rural areas,urban areas,and total population based on the five types of SSPs has shown a decreasing trend in the 21st century as a whole,and the estimated population of SSP1 and SSP5 coincide.SSP3 projected the largest population of rural and total population,and SSP3 estimated the smallest urban population.The population exposure of China's rural,urban,and total population in the early,middle,and late 21st century showed that the high values were mainly distributed in the eastern monsoon region.The exposure of rural population shows that the population exposure in the early 21st century is higher than that in the middle and late periods;the exposure of urban population shows that the population exposure in the late 21st century is higher than that in the early and middle periods;the population exposure of the total population shows that the population exposure is higher than in the middle of the 21st century.The early and late 21st century.In the semi-arid and semi-humid areas,the average population affected by drought is the largest in each year.The number of affected people in towns is far higher than that in rural areas.The estimated drought-affected population of rural and total population of SSP3 is higher than the other 4 routes,but the population of SSP3-calculated towns affected by drought is lower than the other 4 routes. |
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