Fig. 9. Distribution of NO₃^––N fluxes (top of figure) and median NO₃^––N concentration and vertical water flux (bottom of figure) for selected unsaturated zone and ground water sites. For NO₃^––N, fluxes at each study site, the left box shows local unsaturated zone flux estimates based on median, quartile, and minimum and maximum concentrations of all samples collected from the deepest lysimeter (C22f, I32b, M22d, N22c, and W22l). Columns marked with "G.W." show the flux estimates based on reconstructed NO₃^––N source concentrations for ground water (Green et al., 2008) and vertical ground water flux estimates based on age profiles. Ground waters older than 25 yr since recharge are excluded. Rectangles at the bottom of the figure are sized according to the median NO₃^––N concentration for each site (width) and the recharge (height) based on the median vertical ground water fluxes and water table fluctuation estimates.