Europe is burning in this summer

This is actually quite common already, and not just in China. When you have prolonged dry periods followed by heavy downpours you tend to get flash floods, as the ground is so dry that it can't actually absorb the rain quickly enough, so just runs off the hard surface. The ideal rainfall for the ground is light but prolonged.
Yep. Unfortunately, one of the characteristics of climate change (warming surface/colder upper atmosphere) is drier ground/more intense rainfalls.