Physio(/raphy of Werribee Area. 1ST 



This table shows in an interesting way how the various factors 

 operating at any one locality remain uniform in their results 

 throughout all years. As has been stated, the stations are arranged 

 in order, from that with the greatest average fall for the ten years, 

 to that with the lowest. The years of maximum and minimum rain- 

 fall show very nearly the same gradient. 



The average rainfall for the Werribee and Saltwater valleys, 

 published by Gregory, from figures supplied by Mr. Barrachi, is 

 27 in. (ref. 20). 



The Werribee average, however, must be much lower than this, 

 as the figures of the above table are those of a representative ten 

 years, and give an average of 22.5 in. The Commonwealth 

 Meteorologist, treating the area broadly, in his chart of Victorian 

 rainfall, divides the area into zones practically parallel with the 

 coast : — > 



(1) The mountain area with a rainfall 30 in. — 40 in. ; (2) an 

 intermediate belt 20 in. — 30 in. ; and (3) a coastal belt with a rain- 

 fall of 10 in.— 20 in. 



This is not the whole truth, however, as certain local differences 

 occur, and an endeavour is made to bring out these points by means 

 of the diagram shown in Fig. 1. 



Since there is an undoubted lowering of the rainfall from the 

 Divide to the sea, the chief factors must be (1) height above the sea 

 of the station selected, and (2) nearness to the main ranges. The 

 two factors are closely parallel, but not quite so. Selecting these 

 two factors, the diagram (Fig. 1) has been drawn thus : — (a) The 

 sixteen stations are arranged at even intervals with vertical lines 

 drawn to graphically represent the amount of rainfall; (b) In the 

 same order, the stations are again similarly arranged, the vertical 

 lines now representing, inversely, the nearness to the Main Divide, 

 measured as distance from the river mouth; (c) in the third case 

 the vertical lines represent the heights above sea level of the various 

 stations. It was thought that, if these were the only factors, the 

 curves joining the tops of the three sets of lines would closely 

 resemble one another, and that any irregularity in the second curve 

 should be compensated for in the third. This proves to be the 

 case, with one or two interesting exceptions. 



(a) It is clearly suggested by the diagram that the amount of 

 rain received is closely proportionate to the nearness to the Main 

 Divide. The rain-bearing winds travel across the area mainly 

 from the west and north-west, proceeding from the higher to the 



