10-Assessment of Mean Aerial Precipitation Estimation Methods on Natural Watersheds under Varying Geographic and Topographic Terrains across Canada.

Abstract

Estimation of Mean Aerial Precipitation (MAP) is a key component in hydrologic studies. The precipitation amounts at raingauges are used to estimate MAP. Modern estimation techniques of MAP have shifted toward computer technology and satellite imagery. These methods although provide high levels of accuracy of MAP yet traditional techniques because of their simplicity and reliability are still popular. Comparative studies have examined these methods on artificial watersheds involving square boundaries. This paper focuses on assessing the efficacies of these methods through applications on natural watersheds located across various topographic terrains of Canada. Four different methods of estimating MAP are examined and evaluated in natural watersheds from three different topographic terrains. These methods gave comparable results of MAP in any region of interest. These comparable results also reinforce previous claims that no one method is superior to others in the estimation of MAP. Some methods are more preferable than others in certain topographic terrains because they can easily incorporate topographical effects on the occurrence and distribution of precipitation. Computer based MAP methods have proven helpful in faster execution with increased accuracy compared to some traditional methods.