Lead
"What is sand?"
This is a question that my son asked his mother when he was in kindergarten, and she quickly thought of a simple answer: "Sand is a paintbrush of nature." ”
Sand is indeed a paintbrush of nature, it can draw countless beautiful pictures, and most importantly, it can also help us understand and explore nature.
Sand is almost endless in the desert, however, now the whole world is facing a shortage of sand.
Will sand become an important strategic resource in the future?
1. Sand is also very important.
Sand is a very ordinary substance, but we can't ignore its value just because it's ordinary, on the contrary, sand is very "important".
Sand is ubiquitous on the earth's surface, so it should be very abundant, however, the formation of sand is not so easy, and the cohesion and friction between the sand grains grind the rock into fine sand very slowly, up to tens of thousands of years.
This process can be said to be a long grinding, or it can be said to be a very "painful" process, therefore, the sand contains a lot of valuable information, and the sand can be said to be the memory of the earth, which can record the evolution of the earth and the cycle of life.
"Is there a memory of the earth in the sand?"
This is a question that many people will ask, and yes, sand can really record the memory of the earth.
The sand includes not only quartz sand formed after a long period of grinding, but also sea sand washed out by the sea, and sand from the dunes.
These sands contain not only quartz sand, but also other minerals that are the result of weathering and running water, so we can understand the local climate, geological environment and geological age according to the composition of these minerals and the size of the particles.
This is like a "yearbook" of the earth, in which the "growth experience" of each region of the earth is recorded.
Sand is still a paintbrush, a paintbrush to paint beautiful landscapes.
In the desert, the sand blown by the wind will form beautiful sand dunes, these dunes, they are diverse, some like a small mountain bag, some like a small drum, some like a strange totem, some like a small jumping frog.
These sand dunes have different shapes, and they are formed because of the different friction and adhesion between the sand grains, and the change in the direction and magnitude of these forces create a variety of shapes for the sand dunes.
Since there are many shapes, we can use it, and for the shape in the dune, we can see the direction and force of the wind blowing, so the dune is also a "anemometer" that records the square and strength of the wind.
Sand is also a geological material suitable for adventure and exploration.
At the seaside, the sea water washes the rocks, and some rocks sink to the bottom of the sea due to their high density, but some rocks are washed ashore because of their low density, and they are blown by the wind and the sun to form a beautiful beach for a long time.
On the beach, we can see not only colorful shells, but also sand of various colors, which are very beautiful, and many people will take them home and make some small ornaments.
These sands, their colors are so beautiful, this is due to the fact that the sand contains many compounds of metallic elements, which, under the influence of sunlight, become "golden".
Sand not only has beautiful colors, but also some beautiful shapes, which are formed by the wind and the washing of water, and we can understand the movement of wind and water from these shapes.
However, most of these shapes are very small, and some are not as good as a child's little thumb nails, so we need some magnifying glasses to observe these shapes, which are a kind of "mini artwork" of sand.
However, in many places, there is a shortage of sand, why is this?
Second, the global shortage of sand.
People have the impression that sand is very abundant, but now the world is facing a shortage of sand, why is that?
We can understand the shortage of sand from the source of sand.
In nature, there are three main sources of sand: river sand, sea sand, and wind-blown sand in the desert.
The formation process of these three types of sand is very long, therefore, we can say that the yield of sand is very limited.
Of the three types of sand, river sand is the most suitable for construction and engineering use.
As a result, most of the sand is mined from river sand.
River sand is the debris produced by the erosion of the river bank in the process of flowing, these debris, with the push of the current, move downstream of the river, and the sand particles are pushed by the water flow, and their speed is very large, therefore, their surface will be worn out.
Quartz sand in river sand, quartz sand, is a very hard material, the friction and adhesion between the sand grains, are very small, therefore, the quartz sand in the river sand is easy to form a smooth shape, this shape, generally the characteristics of quicksand.
Quicksand is a kind of sand that is very suitable for construction, because its adhesion and friction are very small, and it can be well bonded together to form a hard structure, which is very suitable for construction.
However, extracting sand from here can also have a very large impact on the ecosystem, as it will cause the river to flow faster, which will increase the chance of flooding, which is very dangerous for the inhabitants of the river.
In addition, sand mining can lead to the decline of the riverbed, which is very detrimental to the water management of the river.
The mining of river sand will also lead to greater cohesion and friction between sand particles, which leads to the difficulty of sand transportation, which is very unfavorable for the dredging and transportation of river channels.
Sea sand is formed by the debris deposits in seawater, and most of this sand is washed out by seawater, so we can't extract sand from the beach, because it will damage the ecological environment of the beach.
The wind sand in the desert is formed due to the wind in the desert, and most of this sand is strong sticky sand, and the friction and adhesion between them are very large, so they are not suitable for construction, and even more so for the construction of roads and bridges.
However, we can use it for research, and from the shape of its particles, we can understand the direction and strength of the wind.
3. How to solve the problem of sand shortage.
Sand scarcity is due to limited sand production and excessive sand consumption, so there are two keys to solving sand scarcity: sustainable management of sand and the promotion of alternative materials.
For the sustainable management of sand, the main thing is to manage river sand, which can be extracted, but the amount mined must be below the yield of river sand, otherwise, it will have a serious impact on the ecosystem and water resources.
For the mining of river sand, the principle of moderate mining should be adopted, and this principle is based on the size of the riverbed and the shape of the riverbed to determine the amount of mining.
The amount of mining must not exceed the size of the riverbed, otherwise, it will lead to difficulties in dredging the river and even lead to the decline of the riverbed.
For the management of river sand, a price adjustment policy can also be adopted, and for river sand, a reasonable price can be given, which can not only compensate for the cost of mining, but also provide funds for environmental and ecological protection.
For alternative materials, waste and construction waste can be used, which can be used for construction through simple treatment, so that the need for river sand can be reduced.
In the management of sand resources, it is also necessary to strengthen policy supervision and technological innovation, so as to better promote the sustainable use of sand resources.
epilogue
Sand is a very important resource, but now that the world is facing a sand shortage, it is up to all of us to work together to solve this problem.
In the process of solving this problem, we also need to strengthen the construction of ecological civilization and balance the relationship between economic development and environmental protection.