Hydrostratigraphy and Properties of Aquifer Materials in Dhaka University Campus

Abstract

The reconstruction of hydrostratigraphy by subsurface panel diagrams and 3D block diagrams reveals that three aquifer units exist in the
Dhaka University campus up to the investigated depth of 304 m. Most of the tubewells of Dhaka University Campus are tapping water from
the upper aquifer system. The present groundwater table in the study area is 42m below the surface. The hydrographs show a continuous
declining trend of groundwater table. The average rate of groundwater declination is 2m/year in the study area. The comparative hydrograph
of surface and groundwater shows that the groundwater in the upper aquifer and surface water of the Buriganga river are interconnected.
The regional groundwater flow shows a radial pattern concentrated to the center of the city. The aquifer properties i.e. hydraulic
conductivity and transmissivity values of the aquifer sediments are estimated as 16.15 m/day and 1534 m2/day for the upper or first aquifer
and 5.25 m/day and 131.25 m2/day for the second aquifer, respectively. The hydraulic conductivity of the third aquifer is 7.6m/day. The
values of uniformity co-efficient of the first aquifer ranges from 1.38 to 2.18, second aquifer from 1.3 to 2.3 and third aquifer from 1.8 to
2.64 which indicates all samples are well sorted. To avoid further deterioration of aquifer condition and combat the situation, especially the
continuous groundwater head declination, urgent action plan is required without further delay.