Flood Trend Analysis

[Teddy Nakato]

Dear members, 

I need some help with trend analysis. 

I am working on mapping floods using google earth engine and I extracted time series of flood water extent areas of the river sites I am working on. 

I additionally have streamflow data of these sites. I would like to know if I can use the extracted flood water extent areas for trend analysis or frequency analysis like it is done with the streamflow data. I want to determine if this extracted flood extent area data can be used as a proxy for stream flow.

I used Gumbel's method of Trend analysis. Is there a better method to use in the case of flood extent area data?

Thanks alot for the responses.

Kind regards

Teddy Nakato