Liquid is the theme for this week at Where’s my backpack?
In my view, water (H2O) is the most precious liquid, without which we cannot survive. It is abundant, but clean freshwater is becoming more and more scarce. In the future, it may become one of the most important resources in the world.
Let’s look at some statistics: 70% of earth’s surface is water; 75% of human body; and 90% of human blood is water too. Of all the water that’s there on earth, 97% is in seas and oceans and 2% is icecaps. Of the remaining 1% fresh water, only a small percentage is accessible. And from what’s accessible, 98% water is used for agriculture and industrial use. Water, as a liquid may have many colors. High up in Jiuzhaigou , China, there are dozens of blue, green and turquoise-colored lakes. Originating in glacial activity, they were dammed by rockfalls and other natural phenomena, then solidified by processes of carbonate deposition (travertine). Jiuzhaigou’s water has a high concentration of calcium carbonate, making it so clear that the bottom is often visible even at great depths. The lakes vary in color and aspect according to their depths, residues, and surroundings.
The blue colored water in this picture taken at Jiuzhaigou contrasts sharply with the green trees on the upper part of the image. The water is so clear that the bottom of the lake is highly visible. However, not too many creatures can survive under such high concentration of calcium carbonate; among these are some fishes with a special kind of scales on their body. Water. . . . . . . . . . . what a precious and wonderful liquid!