Warta Geologi, Vol. 46, No. 2, August 2020, pp. 82–87

The effect of land reclamation on water clarity in
Tanjung Tokong using remote sensing

Nurulamani Rosman, Aisah Taufik, Ismail Ahmad Abir*

School of Physics, Universiti Sains Malaysia, 11800 Gelugor,
Pulau Pinang, Malaysia

* Corresponding author email address: iahmadabir@usm.my

Abstract:
Reclamation land project in Tanjung Tokong, Penang is one of the sign of the
rapid urbanization of Penang island due to the increase in population and a
need for land. However, recent increase in public awareness of the negative
effects of land reclamation projects on the local fishing community and the marine
habitats has made it important to study the changes in the coastal water
quality that relates to these projects. Therefore, this study is an initial
attempt to measure water quality, mainly water clarity, using cost-effective
satellite remote sensing images. Secchi disk depth measurements is collected
around the Tanjung Tokong reclaimed land at the same time as the Landsat 8
image of Penang island is recorded. The Secchi disk measurements are compared
and correlated with the reflectance data of the Landsat image resulting in a
correlation equation. Based on the equation, water clarity is then estimated
for previous Landsat images of Penang. Finally, Secchi disk depth measurements
is also collected for the west coast of Penang island for comparison purposes.
Our results show that the NIR (Near-infrared) band is the most sensitive for
water clarity estimation. Furthermore, the water is generally clearer in the
area to the west of Penang island where there are no land reclamation projects.
However, there are other environmental factors which were not take into
account, such as tidal changes, that will also affect water clarity.

Keywords:
Water clarity, remote sensing, Secchi depth, Landsat

DOI :
https://doi.org/10.7186/wg462202007

ISSN
0126–5539; e-ISSN 2682-7549