Base flow in the small coastal basin could provide an insight to the interaction of surface water and groundwater.Its separation in the case study basin inside Zhuhai Campus of Sun Yatsen University showed the varied BFIs,defined as the volume of base flow divided by the volume of total stream flow with different methods.The BFI value fell into a range of 0.43-0.86 for the whole year of 2007 with a maximum of 0.96 in the dry season from November to March,and a minimum of 0.41 in the rainy season from April ...