QUESTION 8. The diagram below is a semivariogram with the main components annotated. Answer all parts 8A to 8C of this question.

8A) Give the values for the nugget, range and sill that you would estimate from this graph. (3 marks)

8B) Explain what these values tell you about the spatial structure of the data from which the variogram was calculated. Use a map to do so. (8 marks)

8C) How does Kriging’s use of the semivariogram help improve interpolation results in comparison with other methods such as Inverse Distance Weighted interpolation? (9 marks)

QUESTION 9. Give one or more annotated diagrams to support your answers. Answer all parts 9A to 9C of this question.

9A) Briefly explain the basic principle of spatial interpolation (5 marks)

9B) Briefly describe the characteristics required of the data, in relation to the phenomenon being interpolated, for interpolation to be meaningful. (8 marks)

9C) When would one use a local interpolation method in preference to a global interpolation? (7 marks)