I suggets to take a look on the following link:

http://www.wmo.int/pages/prog/hwrp/publications/low-flow_estimation_prediction/WMO%201029%20en.pdf (p. 50).

Hi Nawbahar:

You can use it to give you an indication of the behaviour of the catchment and with some additional information you can make some determinations of the nature of the aquifers.

Mandal and Cunnane developed an index for using the FDC in ungauged river catchments in Ireland; they suggest using the 90%ile/50%ile ratio as an indicator of base flow contribution. If you combine this with topographic, meteorological and location data you can start to unpick the system. 

You need to see how the river responds to inputs such as rainfall and/or snowmelt and how it behaves in recession: is it flashy or slow responding. This is where topography and location (are you near the headwaters, or much further downstream) are really important. Any geological data will be useful, but bear in mind that structural controls (such as regionally extensive faults) may have a major impact on baseflow contribution, even in "hard" rocks. Likewise, clay content in unconsolidated materials will also impact.

Tiernan