If any of the researchers have gone through this paper "Urban Rainwater Utilization and its Role in Mitigating Urban Waterlogging Problems—A Case Study in Nanjing, China." Can you please clarify the following doubts?

1. How the authors have calculated the cumulative frequency of rainfall in Table 1 and how to get the modeling coefficient?

2. The authors have considered rainfall duration in 10min,20min, and 30min. Was it assumed or is there any specific to the area concerned?

3. In equation 6, what is the definition of "g"?

Thank you in advance.

A line of reply will be highly appreciable and obliged.