Question

why the ground water is disappearing​

Answer 1

Excessive withdrawal of groundwater coupled by significant de- crease in recharge contributes to the problem. The extent of saline water intrusion is influenced by nature of geological settings, hydraulic gradient, rate of groundwater withdrawal and its recharge (Choudhury et al. 2001). In studying the thickness and geometry of depositional systems, a common procedure is to make use of information from geological research, drilling, and exploitation boreholes. However, these methods are expensive and time consuming, preventing their use on a large scale. In contrast, geophysical measurements can provide a less expensive way to improve the knowledge of a set of boreholes (Maillet et al. 2005). For this reason, in many cases, geophysical prospecting techni- ques can provide complementary data that enable geological correlation, even in sectors where there are no data from boreholes. Indirect geophysical methods (like electrical resistivity tomography (ERT) and VES surveys) generate continuous data throughout a given profile. It is helps in understanding spatial relations between fresh, brackish, and saline water, which commonly coexist in coastal aquifers.

Answer 2

Groundwater is arguably the most important aspect of our collective water security in the 21st century. Farmers draw upon it as a sort of water insurance policy when the rains falter, or when surface supplies prove inadequate. But we take it for granted, in part because — historically speaking — groundwater has been essentially invisible beneath our feet until very recently.

With the advent of satellite-based remote-sensing technology, we now have grown increasingly aware this crucial water resource is in serious danger, and being pumped far faster than it can recharge in many parts of the world. To improve our resiliency to a shifting climate and extend our growing seasons, we must seriously consider not just pumping groundwater to the surface, as we have always done, but also storing today’s surface waters underground to ensure our water security for tomorrow.