A Model of Mixing of Four River Runoff Recharge Sources Using Hydrochemical Tracers in the Problem of Hydrograph Separation

Methods for the analysis of the formation of river water chemistry based on mixing modelsare discussed. An analytical solution for a mixing modelof four recharge sources is given along with the results of its adaptation based on the materials of hydrochemical and hydrological observations over 2013 and 2014 in drainage basinsin Primorski Krai. The analysis and calculations revealed four components of river recharge in these years: rainwater, two types of subsoilwater, and groundwater, the latter forming the base runoff. The estimates of the mixing modelwith four sources and its tests showed a high quality of modeling.