Groundwater pollution
(06/05/2025 - Views: 6)
Groundwater is a form of underground water, stored in layers of sedimentary rocks such as gravel, sand, clay, in cracks, karst caves beneath the Earth's surface, can be exploited for human activities.
According to the distribution depth, groundwater can be divided into shallow groundwater and deep groundwater. The common characteristic of groundwater is the ability to move quickly through layers of porous soil, forming underground flow patterns according to the topography. Shallow groundwater typically does not have a separating layer with surface topography. Therefore, its composition and water level vary greatly, depending on the state of surface water. Shallow groundwater is highly susceptible to pollution. Deep groundwater is usually located in porous rock layers separated above and below by impermeable layers. Geographically, a layer of deep groundwater often has three functional zones: water recharge zone, water transfer zone, and pressurized water extraction zone. The distance between the water recharge zone and the water extraction zone is often far, ranging from several tens to several hundred kilometers. Water wells in the extraction zone usually have pressure. This type of groundwater has good quality and stable flow. In areas of carbonate development, there is often a type of calcium groundwater moving along the carbonate fissures. In coastal sand dunes, there are often freshwater lenses located above the sea level. Groundwater is the main source of household water supply in many countries and regions around the world. Therefore, groundwater pollution has a huge impact on the living environment quality of humans. Factors causing groundwater pollution and degradation include natural factors such as salinity, phosphorus contamination, Fe and Mn levels, and some other metals. Anthropogenic factors include high concentrations of heavy metals, NO-3, NO-2, NH4+, PO4 exceeding permissible levels, pollution by microorganisms. Groundwater degradation is characterized by reduced exploitation capacity, lowered groundwater levels, and land subsidence.