Maps of the radial (top) and vertical (bottom) metallicity gradients in the MW bulge region. The maps show the slopes of the metallicity profiles measured in each pixel within ±1 deg in the corresponding direction. The radial and vertical gradient variations trace well the X-shaped and boxy density components, respectively. The gradients are steeper near the transition regions between high- and low-α populations. The grey background lines reflect the projected stellar density distribution.