Graph of depth with respect to time?

Question

Say I am draining a pond, and I want to graph its depth with respect to time. What would that graph look like approximately (give me a source I can look at please) I have generated such a graph, but I do not know if it is correct, and have no sources to compare it to / cannot find any online at all.

Thanks for any help you can provide.

Answer 1

Based on the usual shape of a pond and assuming that the volume removed per minute remains constant (not always the case as the suction head (or delivery head in the case of a submersible pump) increases as the water level decreases).

If depth is on the Y axis and time on the X axis then the slope will start off gradually (nearly horizontally) and increase as the surface area decreases and hence the increment volume removed changes the depth faster