What are the main characteristics of groundwater quality? What are the characteristics of groundwate

1, Location:

Groundwater is water that exists in cracks in rocks in the earth's crust or in soil voids.

Water that is widely buried below the surface of the earth in various states is collectively referred to as groundwater.

**Mostly atmospheric precipitation. According to the different underground burial conditions, groundwater can be divided into three categories: upper stagnant water, diving water and artesian water.

2. Classification situation:

According to the burial conditions, groundwater can be divided into aerated water, diving water and confined water.

Gas-encapsulated water refers to the water in the air-encapsulated zone above the diving surface, where there is suction water, membrane water, capillary water, gaseous water and temporarily existing gravity water. The water that occurs seasonally above the local aquifer in the air-containing zone is called the upper stagnant water.

Diving refers to gravitational water with a free surface that exists on top of the first stable aquifer below the surface. It is mainly recharged by precipitation and surface water infiltration.

Confined water is the water that fills the aquifer between the upper and lower aquifers. It is subjected to pressure, and when the overlying aquifer is chiseled through, water can rise or eject from the borehole. According to the type of water-bearing voids, groundwater is further divided into pore water, fracture water and karst water.

Pore water is groundwater that exists in the pores of rock and soil, such as loose sand, gravel, and sandstone layers. Fissure water is water that is present in cracks in hard rocks and certain clay layers. Karst water, also known as karst water, refers to groundwater that exists in the cavities of soluble rocks.

3. Total water volume:

Groundwater is a huge family. It is estimated that the total amount of groundwater in the world is as high as 100 million cubic kilometers, almost a tenth of the total water on the planet, and more than the entire Atlantic Ocean!

4. Groundwater quality:

The most widely distributed in groundwater are the 7 ions of potassium, sodium, magnesium, calcium, chloride, sulfate and bicarbonate. The total amount of various ions, molecules and compounds in groundwater is called total salinity, and if the total salinity is less than 1 gram liter, it is called fresh water, if it is less than 1 gram liter, it is called microwater, if it is 3 gram liters, it is called salt water, if it is 3 10 gram liters, it is called salt water, if it is more than 50 gram liters, it is called brine. The content of calcium, magnesium, iron, manganese, strontium, aluminum and other dissolved salts in groundwater is called hardness, and the hardness of high content is large, and the hardness is small.

5. Where does groundwater go:

The vast majority of groundwater movements are laminar flows. In a wide void, if the water velocity is high, it is easy to move turbulently. Groundwater mainly includes precipitation infiltration, irrigation water infiltration, surface water infiltration, overflow recharge and artificial recharge.

Under certain conditions, there is also lateral replenishment. The discharge of groundwater mainly includes springs, submersible evaporation, discharge to surface water bodies, overflow discharge and artificial discharge. Springs are the main natural way of excreting groundwater.

Here's an address dedicated to groundwater, so let's check it out

The content of trace elements is high.

The water quality characteristics of groundwater: clear, stable water quality, but the salinity and hardness are generally higher than that of surface water, and most groundwater can be used as domestic water after simple treatment (disinfection or removal of iron and manganese), which is not easy to be polluted by man.

Groundwater refers to the water that exists in the rock voids below the ground, and in a narrow sense, it refers to the water in the saturated aquifer below the surface of the ground. Groundwater is an important part of water resources, and it is one of the important water sources for agricultural irrigation, industrial and mining and urban areas due to its stable water volume and good water quality. However, under certain conditions, changes in groundwater will also cause unfavorable natural phenomena such as swamping, salinization, landslides, and land subsidence.

1. Characteristics of groundwater.

1. The flow is slow, the water quality parameters change slowly, and it is difficult to recover once the pollution is made.

2. The depth of burial is different, and the law of temperature change is also different.

3. The water quality condition is easy to change after taking it out.

4. The authenticity of the water sample will be affected due to the adsorption or contamination of the water harvesting spike and the loss of some components.

2. Characteristics of surface water.

1. Except for the extremely high salt content of the ocean, the salt content of other surface waters is low.

2. Compared with groundwater, the hardness is lower.

3. Compared with groundwater, the content of pollutants in surface water is very high.

Groundwater and surface water (rivers, lakes, reservoirs, oceans, etc.) are two different links in the hydrological cycle, and they also have different characteristics in terms of hydrodynamics and environmental chemistry, so groundwater pollution has different characteristics from surface water pollution.

1.Groundwater pollution is insidious.

Groundwater is deposited at a certain depth below the surface and separated from the surface by an aeration zone, and is generally difficult to observe directly with the naked eye unless it is exposed by boreholes, and is not contaminated from the color, smell, type of organisms in the water, and dead individuals, unlike surface water; In addition, surface water can be directly related to various human activities that occur on the ground, pollutants are easy to enter the water body, and it is easy to be detected in time, and groundwater has a certain protective ability because of the overlying soil or the aeration zone, especially the poor permeability of the overlying stratum, such as the distribution of cohesive soil layer with a certain thickness, can reduce the amount of pollutants entering through filtration adsorption and the absorption of plant roots, and even make it intercepted in the soil, the aeration zone, and reduce or even avoid the occurrence of pollution.

2.The contamination process is slow.

Compared with the surface water pollution process, the groundwater pollution process is relatively slow. There are three reasons for this: first, the soil and aeration belt covered by groundwater have a certain interception and self-purification capacity, or a certain environmental capacity, and only when the amount of pollutant components is close to or exceeds the capacity of the soil and aeration zone, pollutants can enter groundwater; Second, it often takes a certain infiltration time for the water flow containing polluting components to enter the groundwater through the soil and the aeration zone, and the length of the time required is related to the infiltration intensity, the thickness of the soil aeration zone, and the permeability of the lithology, that is, there is a lag in the time between the polluted water flow entering from the surface and the pollutants detected in the groundwater. The third is that the surface water flow often moves and excretes in the river in the form of a network, the speed is fast, and the time required for renewal and alternation is short, while the groundwater moves in the way of seepage field, the aquifer is widely distributed, the volume is large, and the actual flow rate is far less than the flow rate of the river water, so after the pollutants enter the groundwater, they will spread out to the surroundings, be diluted or reduce the concentration under the action of water and rock. As a result, the time process for pollutants to enter surface water is much faster than that into groundwater, and the process of contamination of groundwater is slower.

3.Groundwater pollution is difficult to control.

The actual flow rate of groundwater is slow, the volume of aquifers is large, and the alternating cycle of water quality is much longer than that of surface water. Global statistics show that the average time of surface water (river) water quality renewal is generally 15 20 days, and the average time of groundwater quality renewal is 1400 years, from the comparison of these two figures, it can be seen that once groundwater is polluted, it is difficult to remove the consequences of pollution in a short period of time by natural processes, and it is difficult to remove pollutants in such a large and deeply buried aquifer by artificial methods, so the solution of groundwater pollution problem mainly depends on source treatment and prior prevention. This is why many scholars believe that groundwater pollution is difficult to control.

Groundwater is characterized by:

Slow flow Water quality parameters change slowly, and it is difficult to recover once the pollution is exposed;

The temperature variation law is also different with different burial depths.

The water quality condition is easy to change after removal;

The authenticity of the water sample will be affected due to adsorption or contamination of the water collector and the loss of certain components.

Surface water is characterized by:

Except for the extremely high salinity of the ocean, the salinity of other surface waters is low;

Less hardness compared to groundwater;

Surface water has a high level of contaminants compared to groundwater.

The difference between surface water and groundwater is that the concept is different, surface water refers to the amount of fresh water that is renewed year by year on the surface, including ice and snow water, river water and lake and marsh water. Groundwater is a water resource that can be provided for human use for a certain period of time. Groundwater is characterized by a slower flow and is difficult to recover from pollution.

Surface water is characterized by low salinity and lower hardness than groundwater. The difference between surface water and groundwater is that the concept is different, surface water refers to the amount of fresh water that is renewed year by year on the surface, including ice and snow water, river water and lake and marsh water. Groundwater is a water resource that can be provided for human use for a certain period of time.

of groundwater. It is characterized by a slower flow and is difficult to recover from pollution. Surface water is characterized by low salinity and lower hardness than groundwater.