1 Why is freshwater important to humanity Nguyen Khanh Linh Hoang Phuong Linh Nguyen Thuy Linh Truong Khanh Linh Phung Thi Nhat Linh Nguyen Duc Manh Tran Thi Ngoc Mai Nguyen Trong Minh Le Hong Thao My ang Vinh Nam Vietnam National University, Hanoi Xuan Thuy, Cau Giay, Hanoi Vietnam, January 22, 2022; Preprint DOI: https://osf.io/c7tgr In the modern world, parallel with the outstanding development of technology and economy is the gradual depletion of natural resources over time. And freshwater is one of the resources that plays an important role in human life but has not received much attention. According to some researched sources, there are reports that: the annual per capita water volume in North Africa and West Asia decreases by more than 30% and very rarely reaches 1,000 m3, although this is a milestone. represents the threshold of severe water scarcity.(Sơn, 2020) “In the US about 40% of rivers in US cities are experiencing water pollution. Bangladesh is facing the risk of 1.2 million people having to use polluted water. Here, up to 85% of the water source is polluted.”(Thoan, 2021) In Vietnam, every year, the number of people who die from lack of clean water is more than 9,000 people, and the number of people with cancer caused by using contaminated water is more than 200,000 people.(Eco248, 2021) Figure 1. Map of the level of meeting the level of clean water needed for each person in countries around the world in 2007.(Rekacewicz, 2008)