German-Vietnamese cooperation for the development of sustainable technologies for karst water management (KaWaTech solutions)

More than a quarter of humanity is dependent on drinking water from karst aquifers. Since precipitation quickly infiltrates into the karst body, there are hardly any storage possibilities on the surface. In the Dong Van Karst Plateau in northern Vietnam, the tropical climate with pronounced dry periods leads to existential supply bottlenecks. Since September 2010, the project area has been a UNESCO Geopark; as a result, tourism will increase there and the water supply problem will become even worse. During the first phase of the project, numerous hydrogeological investigations were carried out. Our focus was on the characterisation and quantification of the existing water resources. Based on climate data as well as geological and hydrogeological mapping, a conceptual hydrogeological model was developed and validated by numerous marking experiments.

Within the framework of KaWaTech solutions, the variability of hydrochemical and microbiological parameters is being investigated in detail at several surface waters and springs used for drinking water supply. As a result of heavy rainfall events, an increased input of pathogenic microorganisms and suspended particles can be observed. These impair the water quality and severely restrict its use. In order to avoid contamination of drinking water and to minimise the risk of abrasion of pumps used for drinking water supply, the establishment of an early warning system is planned. The particle size distribution in the project region during dry periods and the rainy season will be used as a basis for this. Vulnerability mapping will be used to assess the vulnerability of the water resources used and to develop a groundwater protection concept.

Commissioning of the water production plant of Seo Ho in March 2019 by the KaWaTech team under the direction of the IWG