Radial gradients for metallicity (top) and [α/Fe] (bottom) for different distances from the Galactic midplane (in kpc; see the legend). The trends are computed as running medians in bins of 0.5 kpc, with a 40 percent overlap, provided that at least 50 stars are available to compute the median. The shaded areas represent the Poisson uncertainty on the trends. The colours, which are associated to Z distances from the plane, are similar if the |Z| range is the same.