It seems obvious that if you dig or drill into the soil, at some point you will hit groundwater. Drill deep enough and you will reach an aquifer containing enormous amounts of fresh water. After this you can just pump water out of these wells and you will have fresh water aplenty. Or so was the thinking among many for the longest time. As enormous the fresh water reserves in the form of groundwater are – with most liquid fresh water being groundwater – we can literally empty them faster than that they’ll refill.
As the Dust Bowl disaster painfully showed in the 1930s and drought along with surface subsidence issues as in e.g. California’s Central Valley shows today is that we cannot simply use the soil and groundwater and expect no consequences. While the 19th century saw many fresh settlers to the West’s arid and semi-arid regions like California believe in the ‘Rain follows the plow‘ mysticism, the 20th century and these first few decades of the 21st century taught us that tilling the soil and drawing groundwater for irrigation does not change an arid climate into a lush one.
Perhaps ironically, even with increasing droughts, most human settlements use stormwater drainage and combined sewage systems to carry rainwater away, rather than letting the groundwater recharge naturally. Fortunately, more and more regions these days are seeing the necessity of managing groundwater.
Continue reading “Groundwater: Management Of A Much Neglected Lifeline” →
Do you need more proof that we’re living in the future? A group of MIT engineers have found a way for spinach, aka Popeye’s favorite short-term strength booster, to send potentially lifesaving emails regarding explosives in the area.
As the team outlined in a paper published in 2016, the field of plant nanobionics uses nanotechnology to enhance the natural abilities of plants and make them do new tricks. Here’s how this one works: the roots of the spinach plants absorb nitroaromatic compounds such as picric acid from the groundwater, and these transpire up through the stem and into the leaves along with water and other nutrients. When the compounds reach the leaves, they accumulate in the plants’ mesophyll — the inner tissue of the leaves.
A pair of sensors made of single-walled carbon nanotubes are built into the leaves. One sensor is engineered to detect nitroaromatic compounds using near-infrared fluorescent emission, and the other is used as a reference signal. As the the compounds build up in the mesophyll, the IR signal gets stronger. This change is detected by a camera, which triggers an email alert to the researchers within a matter of minutes. After running the experiments with a fancy-pants indium-gallium-arsenide camera, the researchers were able to duplicate the results using a Raspberry Pi and a CCD camera module with the infrared filter removed.
Plants have an ear to the groundwater like none other and absorb a lot of information about the environment around them, so the researchers believe that detecting explosive materials is only the beginning — they could also be harbingers of pollution and other environmental concerns.
Even if there is no threat of landmines in the vicinity, weeds are a problem everywhere. There’s a Raspberry Pi-based solution for those, too.