How to remember the difference between economic and physical water scarcity?

Water scarcity is a phenomenon when the demand for water is greater than the available resource. Water scarcity = problem. It is important to notice the word "demand" as water scarcity does not occur simply where there is no water - it occurs when there is not enough water for population of given area. Now, economic water scarcity refers to the economy. What is economy about? Money. So water scarcity can be thought of as a "money problem" - it happens when the water is present but it is not possible for people to use it - mainly due to lack of proper technology, human, financial and/or institutional resources. The physical water scarcity is a "physical problem". It occurs when there is no water available in any form.