A comprehensive approach of groundwater vulnerability and potentiality assessment of Melaka catchment in Malaysia / Md. Imran Hosen
maps by ArcGIS software. The GIS is very important and effective tool for handling a large amount of geological and hydrogeological data within short time and minimal error. Pumping test data are collected from 210 shallow and 17 deep boreholes to get well inventory information. Analysis of thes...
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Format: | Thesis |
Published: |
2012
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Online Access: | http://studentsrepo.um.edu.my/8328/4/Thesis_Imran_KGA_100053.pdf http://studentsrepo.um.edu.my/8328/ |
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Summary: | maps by ArcGIS software. The GIS is very important and
effective tool for handling a large amount of geological and hydrogeological data within
short time and minimal error.
Pumping test data are collected from 210 shallow and 17 deep boreholes to get well
inventory information. Analysis of these data confirmed that the aquifers consisting of
schist, sand, limestone as well as volcanic rocks are the most productive for
groundwater in the State of Melaka. The term ‘aquifer productivity’ represents the
potential of an aquifer to sustain various levels of borehole supply. The aquifer
productivity map is classified into three categories namely;- high (>12m3/h), moderate
(3.6-12 m3/h) and low (<3.6 m3/h) based on the discharge capacity. The groundwater
potentiality of the study area is 35% low, 57% moderate and 8% high. Seven thematic
maps defining;- depth to water table, net recharge, aquifer media, soil media,
topography, impact of vadose zone and hydraulic conductivity are generated and
integrated to generate the final DRASTIC vulnerability map. The map is then overlaid
on the additional land use map to generate the risk map, which method is called
Modified DRASTIC method. Both methods have been validated using groundwater
quality data. The vulnerability map are classified into three categories namely;- high
(>159), moderate (120-159) and low (80-119). The DRASTIC vulnerability map shows
that an area of 11.02% has low vulnerability, an area of 61.53% has moderate
vulnerability and 23.45% of the area has high vulnerability in the Melaka State. On the
other hand, risk map indicates that 14.40% of the area is low vulnerability (100-139),
47.34% moderate vulnerability (140-175) and 38.26% high vulnerability (>175) in the
study area. The most vulnerability is seen around Melaka, Jasin and Alor Gajah City of
Melaka. The 52 shallow and 14 deep borehole groundwater samples are analyzed for
water quality. The analysis results indicate that groundwater quality is satisfactory for
drinking and other purposes, however turbidity, total dissolved solids, iron, chloride and
cadmium values are exceeded the limit of the drinking water quality standard in very
few cases. The ranges of pH are 4 - 8.2 for shallow and 5.2 - 8.1 for deep boreholes.
Therefore, groundwater in the State of Melaka can be used for drinking and other
purposes, in which some major treatments are recommended in few cases. |
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