What is Waterlogging

Land subsidence and its consequences are at an alarming level in the Southern and low-lying areas of the Mekong Delta. This chapter will discuss the situation of groundwater uses and urban development activities that caused the negative impacts of land subsidence and sea level rise in Ho Chi Minh City and the Mekong Delta region of Vietnam. The PSInSAR technique was applied for land subsidence monitoring and showed that an average subsidence rate at 15 mm/year which is 5 times greater than the effects resulting from the rise of sea level. This implies that land subsidence coupled with sea level rise have been as a major factor contributing to increasing the depth of annual flood and causing inconveniences to the daily lives of residents that suffered waterlogging of between 0.4 – 0.5m. Apart from the restriction of groundwater abstraction, rainwater harvesting – an alternative water sources – is a humanitarian engineering solution to minimize groundwater extraction which in turn to prevent from flood risks caused by land subsidence and the rise of sea level.