Change of heavy rainfall in different countries and regions and its relationship with urbanization factors: a case study over USA,Europe,China,Brazil and India
Severe disasters caused by extreme precipitation events have been increasingly noted worldwide,and they are often attributed to climate change,while the relationship between climate change and extreme precipitation has become one of the hottest scientific frontier issues. In this research,the interannual and interdecadal heavy rainfall amount (HRA),heavy rainfall days (HRD) and heavy rainfall intensity (HRI) in the USA,Europe, China,Brazil and India,from 1981 to 2010 were calculated and compared. the results show that HRA, HRD and HRI increased in the five countries and regions. And on the whole,HRA,HRD and HRI in China, Brazil and India increased significantly higher than those in USA and Europe. Current researches show that atmospheric and oceanic climate indices cannot completely explain the increase of heavy rainfall in five regions. Therefore,we introduce into GDP,UR and AOD as the rapid urbanization characterization in the five countries and regions,and then perform the correlation and scatter diagram between HRA,HRD,HRI and GDP,UR, AOD. The result shows that the correlation in China,Brazil and India with higher GDP,UR and AOD is higher than those in USA and Europe. Therefore,rapid urbanization most likely triggered the significant increase of heavy rainfall.