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Based on the daily precipitation data of 545 meteorological stations in China from 1961 to 2016, the spatial-temporal variation characteristics of rainstorm rainfall and rainy days in different months of China were diagnosed from three aspects: climatic characteristics, variation trend and interannual variation. The results showed that: (1) Rainstorm rainfall and rainy days in different months of China from 1961 to 2016 had similar spatial characteristics in corresponding months. From January to July, the high-value areas of rainstorm rainfall and rainy days gradually expanded from southeast coast to northwest inland, but mainly distributed in the east area of Hu Huanyong Line. From August to December, it shrank from northwest to southeast coastal areas. Rainstorm rainfall and rainy days were less distributed in different months in the west area of Hu Huanyong Line; (2) From 1961 to 2016, the spatial-temporal variation characteristics of rainstorm rainfall in different months in China were basically consistent with that of rainy days. May to August was the most significant month for the variation trend of rainstorm rainfall and rainy days in China. It mainly distributed in the southeast monsoon area, and was mainly increasing trend. The trend of rainstorm rainfall and rainy days in northwest China changed slightly in different months; (3) The interannual variability of rainstorm rainfall in different months in China from 1961 to 2016 was similar to that of rainy days. The fluctuation characteristics from April to October were larger in the northern region. The southern region fluctuated greatly from November to December in January to March. With the development of the month, the high-value areas with large daily fluctuations of rainstorm rainfall and rainy days gradually expanded from southeast to northwest, northeast and southwest, and the fluctuations in southeast tended to decrease, then shrank from northwest, northeast and southwest to southeast, with the increasing fluctuations in southeast. The study has certain reference significance for flood control and disaster reduction and water resources planning and utilization. [ABSTRACT FROM AUTHOR]

In the context of global -warming, there are more frequent heavy rainstorms and extraordinary rainstorms, which leads to growingly severe rainstorm disasters. In previous studies, heavy rainstorms and extraordinary rainstorms were classified into rainstorms so that it was impossible to fully grasp the spatiotemporal pattern of heavy rainstorms and extraordinary rainstorms. Therefore, based on the daily precipitation data of 659 meteorological stations in China, this study calculated the rainfall amount, the rain day, and the rainfall intensity of rainstorms, heavy rainstorms, and extraordinary rainstorms in 1951-2010, and analyzed the spatiotemporal patterns of rainstorms, heavy rainstorms, and extraordinary rainstorms in China. The results showed that: In terms of the proportion to the total rainstorms, rainstorms were the largest, followed by heavy rainstorms and extraordinary rainstorms; in terms of time, the rainfall amount, the rain day, and the rainfall intensity of interdecadal rainstorms and heavy rainstorms in China show a dynamic increase trend; in terms of space, only the rainfall amount and rainy days had an expansion trend, while the rainfall intensity did not change much. Temporally, the rainfall amount and the rain day of interdecadal extraordinary rainstorms were characterized by "increase--decline--increase", while their rain intensity was characterized by "decline-increase-decline". Spatially, there was no significant change in the rainfall amount, the rain day, and the rainfall intensity of extraordinary rainstorms. In short, rainstorms in China were developing towards extremes, which might be a result of combination of human factors and natural factors. [ABSTRACT FROM AUTHOR]

Many regions are pounded with heavy rainfall, causing flood, casualties, property damage and severe destruction to ecosystem in multiple urban areas. Frequent occurrence of extremely heavy precipitation event under the background of global climate change has caused terrible harm on economic and social development, life security, ecosystem, etc. ; brought profound impact on sustainable development of disaster area; become a key factor of global and regional disasters and environmental risk; and been widely concerned by academic circle and all sectors of the society. So severe disasters caused by extreme precipitation events have attracted more and more attention, while the relationship between heavy rainfall with different duration and total heavy rainfall has become the hottest scientific frontier issue. Contribution of heavy rainfall with different duration to the total heavy rainfall has significant spatial differences. Here we used daily rainfall data from 1961 to 2015 of 659 meteorological stations in China. When the rainfall is greater than 50 mm in 24 hours, that is a heavy rainfall event. Heavy rainfall only lasting one day is defined as short-duration heavy rainfall, while heavy rainfall lasting more than two days is defined as long-duration heavy rainfall. Results indicated that: on the basis of duration days defined long-duration heavy rainfall, on the spatial distribution, total rainfall, total heavy rainfall and short-duration heavy rainfall showed "increasing -decreasing -increasing" from the southeast coast to northwest inland in China from 1961 to 2015, and on the whole meteorological station with increasing trend predominant. In the meantime, long-duration heavy rainfall showed "increasing -decreasing" spatial pattern, and on the whole meteorological station with decreasing trend predominant. We detected that there was a belt of becoming drought from northeast to southwest. The contribution of total heavy rainfall to total rainfall as well as long-duration heavy rainfall to total heavy rainfall showed "high in southeast - low in northwest" spatial distribution pattern. On the contrary, the contribution of short-duration heavy rainfall to total heavy rainfall showed " low in southeast - high in northwest" spatial distribution pattern. The contribution trend of total heavy rainfall to total rainfall and short-duration heavy rainfall to total heavy rainfall showed " increasing -mosaic with increasing and decreasing -increasing" spatial distribution pattern from northeast to southwest, and on the whole meteorological station with increasing trend predominant. On the contrary, the contribution trend of long-duration heavy rainfall to total heavy rainfall showed mosaic with increasing and increasing in the northeast, slightly decreasing in the southwest, and on the whole meteorological station with decreasing trend predominant. There was a climate transition zone from northeast to southwest, which was essentially coincident with the arid zone. The results suggested that the precipitation in China was changing to extremely accompanied by short-duration storm increased significantly. Chinese heavy rainfall especially the increase of short-duration heavy rainfall suggests that human activity is likely to be triggered an increasing in extreme precipitation. [ABSTRACT FROM AUTHOR]

In the context of global climate change and rapid urbanization, climate governance has become one of the unavoidable challenges of human society. Therefore, climate engineering is increasingly mentioned in the international climate negotiations. For solar radiation management with the most controversy in climate engineering method, based on two scenarios of climate engineering (G4) and non climate engineering ( RCP4.5) of BNU-ESM model. 95% and 99% percentiles of daily rainfall data during 2010-2099 were taken as thresholds of heavy rainfall and extreme rainfall events. The data of over threshold sampling (POT) were fitted by Weibull distribution to diagnose the heavy rainfall and extreme rainfall in 10, 20. 50 and 100 years of return period. The results showed that: in two scenarios, strength of heavy rainfall and extreme rainfall enhanced with return period increased, and they showed a southeast high-northwest low spatial characteristics. Climate engineering, in general, contributes to the increase in heavy rainfall and extreme rainfall in China, as well as spatial heterogeneity, which represents the suppression of heavy rainfall and extreme rainfall in parts of the country. This research is of great significance for the future global climate control and regional climate adaptation. [ABSTRACT FROM AUTHOR]