TITLE:
Groundwater Resource Mapping through the Integration of Geology, Remote Sensing, Geographical Information Systems and Borehole Data in Arid-Subarid Lands at Turkana South Sub-County, Kenya
AUTHORS:
Daniel Nyaberi, Justus Barongo, Patrick Kariuki, George Ogendi, Evans Basweti
KEYWORDS:
Arid-Subarid, Groundwater, GIS, Remote Sensing, Borehole Data, Integration
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.7 No.12,
December
16,
2019
ABSTRACT:
The integrated approach of various
techniques which historically have been used independently is key to successful
exploration, development, exploitation and management of the groundwater
resources. The integration of Remote Sensing (RS), Geographical Information
Systems (GIS) and Borehole data has been used in the study area to assess their
applicability in groundwater investigation. The area of study lies in the arid
and semi-arid lands (ASALs) where principally remote sensing data has been used
in extraction of various thematic maps (lithology, lineament, drainage density,
and Digital Elevation Model Maps) for groundwater assessment. The GIS platform
was used in integrating the RS data and data of productive boreholes. The
lineaments generated through remote sensing agree well with structural
geology of the area, where high density lineament points overlays the points of
intense faulting. Lineaments found in the area correlate well with fault zones,
fractures, and lithological contrasts as supported by geological map and
structural map. Weathering, faulting and fracturing of the rocks mean a
possible increase or a reduction in specific capacities as observed in
productive boreholes in sedimentary rocks or igneous/basaltic rocks of the
area. Similarly, it is noted that the degree of faulting affects the degree of
radius of influence of a borehole in a particular area. These analyses show
that groundwater potential within the Sub-County varies spatially with high
dependency on geological structures in the basement region and more on geology
within the volcanic and younger sediments.