Topographic complexity and obstacles surrounding any meteorology station show their deep effects in the wind direction and speed measurements. In wind energy calculations such effects must be quantified on the basis of observed data and accordingly taken into consideration in regional wind energy potential assessments. A point cumulative semivariogram technique is proposed and implemented for the identification of such complexities in a given region. This technique provides means of determining the radius of influence around each meteorology station and on the basis of its variation with distance the terrain around the meteorology station is descriptively classified into one of the five terrain classes. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.