Abstract:
The Barind Tract is one of the major physiographic units of Bangladesh. During the
dry period the discharge from shallow and hand tube wells become minimum and
some times it becomes completely nil. Out of total 13 Upazillas, comprising the
Barind Tract, Sapahar and Porsha Upazillas, situated in the High Ba.rind are
adversely affected by water shortage. The Ba.rind region is now in an acute state of
deforestation as a result the scarcity of surface water sources and low rainfall.
Considering the above hydrogeological problem, geophysical investigation has
been carried out in this area and an attempt has been made to study the feasibility
of groundwater sources and characteristics of groundwater aquifer; particularly its
depth and thickness.
The lithological characteristics encountered in different drill holes enabled to divide
the subsurface zone into three lithostratigrahic units up to 70 m depth from the
ground surface. These are: top sandy and silty clay aquitard unit, fine to coarse sand
aquifer unit and silty shale unit at the bottom. The top two layers units were
underlain by silty clay unit in places. From the study of 21 deep tube well borelogs,
it is evident that the main aquifer does not occur within the upper 300 m, and the
composite aquifer, the only exploitable one in the area is present within the depth
of 100 m.
SLratigraphic panel diagram of the study area is also in good agreement with the
geological cross-sections drawn for the study area.
Clay-sand interface map also indicates a diverging zone in the study area. While the
thickness map of top sandy and silty clay layer indicates an E-W elongated thick
zone located in the northeastern portion of Sapaluu· Upazilla.
It is observed from the maximum and minimum elevation of groundwater table
map that the central pmt of the study area represents a prominent N-S elongated
diverging zone. The groundwater flqws radially towards east, west, north and south
from the central pm·t of the study area.--------
Description:
This Thesis is Submitted to the Department of Geology and Mining , University of Rajshahi, Rajshahi, Bangladesh for The Degree of Master of Philosophy (MPhil)
