You can see the picture.This is a very old experiment,which tell us how water is collected in a cintainer and the figure depicts the effect use of water outdoors.
You can use a plastic to cover the ground and let both side hold down by stones.You need to find another stones to put in the middle of the sheet and the middle of the sheet transformed into a lower part,which compare with the high parts.Everytime the rain comes down or other forms of water such as snow,rime drop out on the sheet ,water will be accumulated in the middle of the sheet,which happens to be the lower part.And then the water dips into the container,which is positioned directly under the stone,thus the water is collected.Sorroud the water container are green plants,which planted to assimilate the water in case the container is full and wwter runs out.
