Analysing bunch of data

#1
Hello!

I have a question about statistical testing on hydrological statistics - I am trying to find a correlation on the link between a multitude of values and arguments (like precipitation and number of cases, etc). My question is what kind of test should be used to find a connection between different arguments. For example, I need to find a connection between number of flash flood cases and the size of the basin (file attached). What kind of test should be used, assuming there is no normal distribution and can I use the same on other such comparisons?
 

Attachments