Question

although about two -third of the earth's surface is covered by water yet one of the cities of Africa has run out of water. why this is so?​

Answer 1

This is because only some percent of water is drinkable for human rest contains too much salt in it or is dirty.

Answer 2

This is because out of the water present on the surface of the earth, only 2.75% of the water is fit for consumption. The rest 98% of water is in the oceans, which is not deemed fit for drinking and daily usage.

Out of the 2.75% fresh water, 2% of water is stored in the form of ice in glaciers and the rest of the water left fit for consumption is either groundwater or is available to us through rivers, lakes or ponds, which are also drying up due to human activities or are becoming polluted.