Constrained least square method(LSM) was introduced to conduct three or more components hydrograph separation with stable isotopes considering that just one tracer was needed,while more than one independent tracers were required by end member mixing approaches (EMMA).Isotope hydrograph separation of Hailuogou glacier which lays the east edge of the Qinghai Tibet Plateau was analyzed as a case study.With isotope monitoring data(δ18O，δ18H),the application of the constrained least square method showed that approximately 73%,18%,and 9% of the stream flow was recharged by snowmelt,groundwater and precipitation,respectively.The results were similar to EMMA and previous studies.Through analysis,the new method reduced the uncertainty of EMMA when complementary tracer was added.Hence,the results could be used as a corroboration of other research methods
