Page 54 - C:\Users\am_se\OneDrive - Higher Education Commission\Desktop\FlipBook\

International Conference on

Recent Trends in Environmental Sustainability

ESCON22/CDMP/19
Groundwater arsenic modelling using geospatial techniques for a mega city, Lahore

1*
2
Syed Umair Shahid , Sadaf Javed and Javed Iqbal 3
1 Centre for Integrated Mountain Research, University of the Punjab, Lahore
2 Department of Meteorology, Comsats University Islamabad
3 Institute of Geographical Information Systems, National University of Sciences and
Technology, Islamabad
Correspondence: umair.cimr@pu.edu.pk
Abstract

Water quality is considered as a major issue in mega cities of developing countries. The city of
Lahore has over 10 million population with the highest population density in the Punjab
Province, Pakistan. The study was designed to assess and model the groundwater arsenic in the
study area. A field survey was conducted to collect the water samples (n = 87) from tubewells
from different parts of Lahore, i.e., Private housing societies, the area that comes under the
jurisdiction of Water and Sanitation Agency (WASA), Lahore, etc. The Hydride Generation-
Atomic Absorption Spectroscopy was used to analyze arsenic in these water samples. The data
exploration and analysis were performed based on the directional range, rose diagram, omni-
directional variogram and isotropic variogram using R statistical software. The spatial
distribution map was generated using the semi variogram model that showed the lowest root
mean square error to come up with the best groundwater quality map. The spatial distribution
map of groundwater arsenic showed that the arsenic concentrations above WHO guideline (10
µg/L) exist almost in the entire study area, whereas the concentrations are above the National
Standards for Drinking Water Quality (NSDWQ) of Pakistan (50 µg/L) in some areas of Ravi
Town (Farrukhabad/Shahdra). Getis-Ord Gi* statistics revealed a significant (p < 0.05) hotspot
of arsenic in the vicinity of River Ravi whereas the arsenic concentrations had a decreasing
trend in the eastern parts of the study area. In order to provide safe drinking water to the citizens
of Lahore, it is recommended that the arsenic removal plants should be installed as an
immediate remedial measure at all the tubewells with arsenic levels (>50ppb) along River Ravi
and nearby areas especially in Ravi Town (Farrukhabad/Shahdra). Moreover, the spatial
modelling techniques used for analysis of groundwater arsenic can help in the improved
management of drinking water quality.

Keywords: Arsenic, Directional range, Spatial Interpolation, Groundwater, Semi-Variogram

Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus

21