9.1.1. Concept and Purpose

Try these first

1. 1.

   What does the Theissen Polygon Method estimate?

   Hint

   Focus on how rainfall is analyzed in a catchment.

2. 2.

   Name one of the main assumptions of the Theissen method.

   Hint

   Think about the distribution of rainfall across the area.

3. 3.

   What assumption does the Theissen method make about rainfall distribution?

   • Uniform across polygons
   • Concentrated near gauges
   • Varying with elevation

   Hint

   Consider how rainfall is treated within the areas defined.

4. 4.

   True or False: The Theissen Polygon Method takes topography into account.

   • True
   • False

   Hint

   Think about how elevation changes could affect rainfall.

5. 5.

   Given the coordinates and rainfall measurements for four rain gauges in a rectangular catchment, determine the area-weighted average rainfall using the Theissen Method's steps.

   Hint

   Remember to visualize the area each gauge covers.

6. 6.

   In a mountainous catchment area, you have the choice to use either the Theissen Method or the Isohyetal Method. Discuss the implications of choosing one over the other based on your observations.

   Hint

   Consider the terrain and environmental influence on rainfall.