Abstract

The paper introduces a formula determing terrain effect in vertical deflection, showing the need of determing effective radius (Rhl) of integral areas, employing methods to specify Rh, resulting in northwest mountainous and highlands (Gia Lai-Kon Tum) mountainous areas. The survey results show Rhl simulated for the northwest mountainous and highlands (Gia Lai-Kon Tum) mountainous areas are of 60 and 50 km respectively.