Weighted Average Method for Land Grading Design

Abstract

Based on the theory of the least squares and the statistical properties of the best statistic with an unbiased estimate and minimum variance, a new method for land grading design is presented. Although it is based on least-squares theory, it does not have the cumbersome and time consuming calculations of the terms of the simultaneous equations that appear in the conventional least-squares method. In rectangular fields, the method is as accurate as the conventional least-squares method. In irregularly shaped fields the results are different but the differences are negligible. Since the developed equations can be solved by using a calculator in statistical mode and a readily available table, the proposed method has the advantage of being amenable to hand calculation.