Due to excessive groundwater pumping under the city of Siem Reap, water pollution, periodic flooding and degraded ecosystems of Tonle Sap, there are current and emerging challenges to the stability of the Angkor World Heritage Site and its building foundations. These complex water and environmental management issues of World Heritage site, biosphere reserve, and urban management nexus were addressed using sustainability science approaches in order to help restore and preserve Angkor World Heritage site’s water management system.
Under this study, three main problems have been identified:
- Water pollution by directly dumping garbage near river and wastewater discharge linked to health problems of people living in Tonle Sap and for fish productivity,
- Over-exploitation of groundwater which could threaten the stability of temples in Angkor World Heritage Site, and
- Deforestation leading to changed flow patterns in Siem Reap River linked to decreased fish productivity.
A research on water balance analysis was carried out and found a water deficit of 229.5 million m3 in 2014 in Siem Reap attributable to the increasing number of tourists to the area. On groundwater, simulation results of scenarios revealed that potential drawdown of groundwater level and land subsidence to Angkor World Heritage Site would occur in all scenarios in a dry year of 50 return period. On land use change, there is a south-north gradient of increasing deforestation, and that the rates of deforestation were at least 1.5 times higher during the period 2000 –2014 in comparison to that of 1989 –2000.