TITLE:
Influence of Seasonal Ground Water Level Fluctuations on the Stability of the Rohingya Refugee Camp Hills of Ukhiya, Teknaf, Cox’s Bazar, Bangladesh—A Threat for Sustainable Development
AUTHORS:
Abu Taher Mohammad Shakhawat Hossain, Sheikh Jafia Jafrin, Purba Anindita Khan, Mahmuda Khatun, Tanmoy Dutta, Mohammad Hasan Imam, Ruma Bakali, Hossain Md. Sayem, Mohammad Shakil Mahabub, Mohammad Emdadul Haque
KEYWORDS:
Stability, Pore Water Pressure, Ground Water Level, Rain & Risk Map
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.11 No.5,
May
31,
2023
ABSTRACT: Bangladesh is a south Asian Monsoonal Country and the recent
precipitation pattern in the Cox’s Bazar area of Bangladesh is changing and
increasing the number of monsoonal slope failures and landslide hazards in the
Kutubpalong & Balukhali Rohingya camp area. An attempt has been made to see
the influence of seasonal variation of ground water level (G.W.L.) fluctuations on the stability of the eco hills and
forests of Ukhiya Teknaf region. Ukhiya hills are in great danger because of
cutting trees from the hill slopes and it is well established that due to
recent change of climate, short term rainfall for few consecutive days during
monsoon might show an influence on the factor of safety (Fs) values of the camp
hill slopes. A clear G.W.L. variation between dry and wet seasons has an
influence on the stability (Fs) values indicating that climate has a strong influence
on the stability and threatening sustainable development. A stable or
marginally stable slope might be unstable during raining and show a variation
of ground water level (G.W.L.). The generation of pore water pressure (P.W.P.) is also influenced by seasonal variation of
ground water level. During wet season negative P.W.P. called suction plays an important role to occur
slope failures in the Ukhiya hills. Based on all calculated factor of safety
values (Fs) at different locations, four (4) susceptible landslide risk zones
are identified. They are very high risk (Fs = 0.18 to 0.46), high risk (Fs =
0.56 to 0.75), medium risk (Fs = 0.76 to 1.0) and marginally stable areas (Fs ≈ 1). Proper geo-engineering measures must be taken by
the concerned authorizes to reduce P.W.P. during monsoon by installing rain
water harvesting system, allowing sufficient drainage & other geotechnical
measures to reduce the risk of slope failures in the Ukhiya hills. Based on the
stability factor (Fs) at different slope locations of the camp hills, a risk
map of the investigated area has been produced for the local community for
their safety and to build up awareness & to motivate them to evacuate the
site during monsoonal slope failures. The established “Risk Maps” can be used for future geological engineering works as well as for
sustainable planning, design and construction purposes relating to adaptation
and mitigation of landslide risks in the investigated area.