WAsP prediction errors due to site orography

The influence of rugged terrain on the prediction accuracy of the Wind Atlas Analysis and Application Program (WAsP) is investigated using a case study of field measurements taken in rugged terrain. The parameters that could cause substantial errors in a prediction are identified and discussed. In particular, the effects from extreme orography are investigated.

A suitable performance indicator is developed which predicts the sign and approximate magnitude of such errors due to orography. This procedure allows the user to assess the consequences of using WAsP outside its operating envelope and could provide a means of correction for rugged terrain effects. (au).