I think the leading cause of water scarcity is too much usage, pollution, and global warming. These might be a few things but these are mostly the things that have the most effect on water scarcity.
Hope this helps
Quantitative observations are where you make an observation on something having to do with numbers or high amounts of measurement. It has to have numbers or measurements involved. IT CAN NOT BE AN INFERENCE. Hope this helped
Jamestown belongs to the 1960's