R help - Sep 2003 - Is calculating a Lake Ratio possible with R?

If I display a line chart, with peaks and valleys, and visualize rain
falling on a mountain range, filling in all the valleys. This produces a
series of lakes between peaks. In case the highest peak s not at the right
most edge,  erect a dam on the right to back up the water to the highest
peak, at the far right to collect all the water from the previous high point
in a final, artificial lake. 

Now calculate the total volume and the volume of the land mass.

If we divide the total volume of water by the volume of the earth below it,
we have the Lake Ratio. 

If someone has done something similar to this please let me know.

Thanks 

Lawrence