For rough surveys or traverse of small area, adjustment can also be carried out graphically. In this method of balancing, the locations and thus the coordinates of the stations are adjusted directly. Thus, the amount of correction at any station is proportional to its distance from the initial station .

Let P_o Q_o R_o S_o T_o P' is the graphical plot of a closed-loop traverse PQRSTP. The observed length and direction of traverse sides are such that it fails to get balanced and is depicted in its graphical presentation by an amount P_o P'. Thus, the closing error of the traverse is P_o P' (Figure 29.2). The error P_o P' is to be distributed to all the sides of the traverse in such a way that the traverse gets closed i.e., P' gets coincides with P_o in its plot. This is carried out by shifting the positions of the station graphically. In order to obtain the length and direction of shifting of the plotted position of stations, first a straight line is required to be drawn, at some scale, representing the perimeter of the plotted traverse. In this case, a horizontal line P_o P' is drawn [Figure 29.3 (ii)]. Mark the traverse stations on this line such as Q_o, R_o, S_o and T_o in such a way that distance between them represent the length of the traverse sides at the chosen scale. At the terminating end of the line i.e., at P', a line P' P a is drawn parallel to the correction for closure and length equal to the amount of error as depicted in the plot of traverse. Now, join P_o to P_a and draw lines parallel to P' P_a at points Q_o, R_o, S_o and T_o. The length and direction of Q_o Q_a, R_o R_a, S_o S_a and T_o T_a represent the length and direction of errors at Q_o, R_o, S_o and T_o respectively. So, shifting equal to Q_o Q_a , R_o R_a, S_o S_a and T_o T_a and in the same direction are applied as correction to the positions of stations Q_o, R_o, S_o and T_o respectively. These shifting provide the corrected positions of the stations as to Q_a, R_a, S_a,T_a and P_a. Joining these corrected positions of the stations provide the adjusted traverse P_a Q_a R_a, S_a T_a [Figure 29.3 (i)].

Figure 29.3 Graphical method of balancing a traverse

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