What are the factors that control groundwater flow through an aquifer?
Water first enters an aquifer through gravity-induced downward movement (percolation), but it also flows in a lateral direction within an aquifer. This flow can occur due to the dip (slope) of the aquifer or artificial conditions induced within the aquifer, such as pumping or recharging. Natural groundwater flow through an aquifer is relatively slow and [...] Read more
Do wells showing shallower water levels yield more water?
Regionally, the top surface of the saturated zone is visualized as flat as the top of a table and hence this surface is referred to as the water table. The regional water table is not as flat as we presume. The water table tends to follow the shape of the topography. Therefore, the water table [...] Read more
If the terms water table and water level mean more or less the same then why do we have two different terms?
Sometimes they mean the same, but not always. While the uppermost level (top) of the saturated zone in an unconfined aquifer is the water table, the water level seen in a well is commonly referred to as water level. When a well is dug in an unconfined aquifer, water from the formation seeps into the [...] Read more
Where does this water which eventually provides us with so much groundwater, come from?
Rainfall (precipitation), an integral part of the hydrological cycle, is the source of all fresh water on the earth. We tend to misjudge the enormous quantity of water brought down from rainfall in our neighbourhood. For example, the volume of 1 metre (1000 mm) of rainfall that falls over 1 hectare (10000 sq. m) of [...] Read more
Which rock formations are suitable for transmitting groundwater?
From the hydrogeology point of view, rock formations are categorized conveniently as unconsolidated (loose), consolidated (hard) and semi-consolidated. Recent and older alluviums are unconsolidated sedimentary formations, usually as alternate beds of sand and clay (or shale) with varying thickness and proportion. The sand formation is a natural carrier of water; the coarser the grain size [...] Read more
We get so much water from underground rocks. Are there natural streams flowing underground?
Groundwater moves through porous rock formations, similar to water flowing through a sponge with interconnected pores. In nature, no space remains empty. Therefore, the pore space within the underground rock formations, no matter how small, remains filled either with air or water (sometimes oil and gas in deeper formations). Given a continuous supply, water enters [...] Read more
How are harmful elements like Iron, Arsenic, and Fluoride removed from drinking water?
Common methods of treating drinking water to remove/reduce the TDS and other harmful ions like Iron, Arsenic and Fluoride are Membrane separation Oxidation-flocculation-filtration Use absorbents such as activated alumina, activated carbon, chemical resins, etc. Any of the above techniques are used either exclusively or in combination, depending on the proposed usage and the size of [...] Read more
Why should a common person bother to understand groundwater?
We all are groundwater users. Farmers use it for irrigation, industries for production and a vast majority of the population use it for drinking and domestic purposes. Although a renewable resource, Groundwater is limited in its occurrence in time and space. The mindless pursuit for extracting more and more groundwater by all the users has [...] Read more