A precise gravimetric geoid model is determined by using Stokes formula assuming that there is no topography above the geoid. Then, the geoid model is simply corrected by considering the constant crustal density of 2670 kg m⁻³ for topographical mass. In fact, the actual density of topographical mass differs about ±20% from the constant value. Recently a global crustal density model within 30″ resolution has been released by the University of New Brunswick in Canada. The paper is devoted to the study of the effect of using this model on the accuracy of gravimetric geoid in a mountainous region in Turkey. Numerical results prove that the differences in the geoid height due to this model may reach up to several decimetres, which should not be ignored in a precise geoid modelling with 1-cm geoid. Thus, it is concluded that the effect of topographical density variations, contained in this model, is significant and should be taken into account in precise geoid determination, particularly in mountainous regions.

假定大地水准面以上没有地形，则使用斯托克斯公式确定精确的重力大地水准面模型。然后，只需考虑2670 kg m ^-3的恒定地壳密度即可简单地校正大地水准面模型地形质量。实际上，地形质量的实际密度与恒定值相差大约±20％。最近，加拿大新不伦瑞克大学发布了30英寸分辨率以内的全球地壳密度模型。本文致力于研究使用该模型对土耳其山区重力大地水准面精度的影响。数值结果证明，由于该模型，在大地水准面高度上的差异可能达到几分之一米，这在使用1厘米大地水准面的精确大地水准面模型中不应忽略。因此，可以得出结论，该模型中包含的地形密度变化的影响是显着的，在确定大地水准面（特别是在山区）时应予以考虑。