Study Of Radium Isotope Tracer Gahai Lake Undergroundwater Discharge Flux

In recent years, the Qinghai Lake water level fluctuating, caused the relevant researchinstitutions and scholars, has become the hot spot of research. Research mainlyfocused on the process and characteristics of basin water balance, water chemistry andwater balance related to surface water. The characteristics of attention in QinghaiLake basin groundwater and groundwater,and is an indispensable part of the lake inthe arid areas. The main reason for Qinghai Lake groundwater research can beattributed to a lack of data of groundwater monitoring and the difficult. Gahai QinghaiLake as the sub sea, has certain instruction significance of groundwater on QinghaiLake.Nature can be detected and the radium isotope research significance of223Ra,224Ra,226Ra and228Ra, these four radium isotope is considered to be a strong setof quantization of submarine groundwater discharge natural tracer. Drain into the bayof groundwater containing high activity of radium, if other sources of radium inseawater is negligible, and radium movement in seawater by diffusion, neglecting theconvection, so we can calculate the submarine groundwater discharge according to theoffshore flux and groundwater radium activity of radium. Widely used in marinescientific research radium isotope tracer method.Input the radium isotope tracer study of Gahai Lake water, in2013June in Gahaicollecting water samples. Along the long axis and short axis of Gahai design of twosampling sections are a total of15sampling points. Water samples were collectedfrom each sampling point25-50L plastic bucket. Back to the laboratory immediatelyafter the MnO2fiber enrichment of water enrichment, water flow control within650ml/min, and then use the radium delay counter and gamma radium isotopeconcentrations measured spectrometer. Gahai Lake of223Ra,224Ra,226Ra and228Ra,distribution, water residence time and the groundwater discharge flux has done theresearch, found that desorption of radium isotope source of Gahai are diffusion andsuspended particulate matter groundwater discharge, lake bed sediments,Groundwater discharge> sediment diffusion> suspended particle desorption;223Ra,224Ra,226Ra and228Ra, distribution in the Gahai Lake, short half-lifeof223Ra,224Radistribution is reduced to the center of the lake shore;228Ra distributionis not obvious, the226Ra short axis in Gahai Lake presents the experience rule isdifferent from the oceanographic research, increased from the shore to the center ofthe lake the average water Gahai Lake; the longer residence time for an average of13.17days; in223Ra,224Ra as the basis for the calculation ofGahai Lake groundwaterfluxes were0.0049m3m2d-1and0.0056m3m2d-1,close to the actual situation.