Deep groundwater recharge mechanism in the sedimentary and crystalline terrains of Sri Lanka: A study based on environmental isotope and chemical signatures

K.S.G.S. Priyadarshanee, Zhonghe Pang, E.A.N.V. Edirisinghe, H. A. Dharmagunawardhane, H.M.T.G.A. Pitawala, J.D.C. Gunasekara, I.A.N.D.P. Tilakarathna