I do think your post is based on previous paradigm “groundwater development” when for especially irrigation purposes groundwater development considered as important and evaluation of fluctuation in water table seasonally and annually used to be carried out.
Presently, due to groundwater depletion and increased contamination, it is urgently required to take stock of this resource in terms of supply and demand. As such, there has occurred a paradigm shift from “groundwater development” to “groundwater management”.
Aquifer mapping is a process wherein a combination of geologic, geophysical, hydrologic and chemical field and laboratory analyses are applied to characterise the quantity, quality and sustainability of groundwater in aquifers. It has a purpose. An accurate and comprehensive micro-level picture of groundwater in India through aquifer mapping in different hydrogeological settings will enable robust groundwater management plans at the appropriate scale to be devised and implemented for this common-pool resource.
Map of the aquifers also contains other base map features (e.g., rivers and lakes, roads, topographic contours).
Aquifer classification takes into account1) the level of development and vulnerability of the aquifer to contamination and 2) the ranking value component (a numerical value that indicates the relative importance of an aquifer). Includes brief descriptions of how the aquifers are delineated, the general sources of information used, and the applicability and limitations of the map. Also included is a reference to where more information on the aquifer classification system can be found.
A summary of information for each aquifer, including: the aquifer number, descriptive location, classification, ranking value, aquifer size, productivity, vulnerability, demand, type of water use, and quality and quantity concerns. This information corresponds to each of the aquifers completely defined on the map. Information for aquifer polygons that are only partially in the map is not included in the table; this is a technical limitation of the GIS.
Aquifer mapping is a multi-disciplinary holistic scientific approach for aquifer characterization. It leads to aquifer-based groundwater management. Mapping of aquifers helps determine the quantity and the quality of groundwater in a particular area, including:
a. Vertical and lateral extent of aquifers
b. Depth to water level/ piezometric surface in the aquifers
c. Productivity of the aquifers
d. Concentration of various chemical constituents in groundwater in different aquifers
e. Current stage of groundwater development in various aquifers
f. Identification of recharge and discharge areas of the aquifer
g. Delineation of vulnerable areas with regard to exploitation and contamination
For more detail please go through the following link
Its more than just 2D maps prepared from satellite images. You need borehole data, water quality data and other hydro-geological information to ascertain how the aquifer is distributed in space and expected to behave with time.
To understand this you can refer to one of my papers which is based on my M.Tech. thesis.. " AQUIFER GEOMETRY, BASEMENT-TOPOGRAPHY AND GROUND WATER QUALITY AROUND KEN GRABEN, INDIA".
Aquifer mapping is indeed a map showing groundwater and its allied information. It has got immense application in vulnerability assessment of aquifers from contamination point of view. Kindly follow the following papers.
Localization of Arsenic Contaminated Zone of Domkal Block in Murshidabad, West Bengal using GIS-based DRASTIC Model
GIS-Based Geospatial Mapping of Arsenic Polluted Underground Water in Purbasthali Block in Bardhaman, West Bengal