The impacts of climate change and human pressure in groundwater have been greatest threats facing small islands. This paper represents a case study of groundwater responses towards the climate change and human pressures in Manukan Island Malaysia.
SEAWAT-2000 was used for the simulations of groundwater response in study area. Simulations of six scenarios representing climate change and human pressures showed changes in hydraulic heads and chloride concentrations. Reduction in pumping rate and an increase in recharge rate can alter the bad effects of overdrafts in Manukan Island.
In general, reduction in pumping rate and an increase in recharge rate are capable to restore and protect the groundwater resources in Manukan Island. Thus, for groundwater management options in Manukan Island, scenario 2 is capable to lessen the seawater intrusion into the aquifer and sustain water resources on a long-term basis. The selection of scenario 6 is the preeminent option during wet season. The output of this study provides a foundation which can be used in other small islands of similar hydrogeological condition for the purpose of groundwater resources protection.
Freshwater in tropical small islands usually depends on recharge, quantity and surface storage (Aris et al. 2008). Most of tropical small islands have limited sources of freshwater, no surface water or streams in exploitable form. Thus, fresh groundwater is the sole option to meet the water demand in tropical small islands. The inhabitants of these islands mostly depend on groundwater to meet their needs, particularly for drinking and tourism purposes. The freshwater lens on tropical small islands may easily be overexploited or polluted due to dense development impacted by tourism expansion combined with improper management and vulnerable to climate change.
Authors: S. M. Praveena, A. Z. Aris