Background
The Mekong Delta offers natural resources for over 17 million inhabitants living in 13 of the 63 provinces of Vietnam. Frequent flood and drought events, increasing salt water intrusion and salinization of soils, limited drinking water availability, unsustainable land use intensification and sand mining, coastal and river bank erosion, subsidence, and the growing threat of climate induced sea level rise and typhoons all have negative effects on people’s lives in the Delta.
Furthermore, regulatory measures at the upper reaches of the Mekong, i.e. the construction of hydropower dams, lead to severe changes in discharge, sediment, and bedload patterns downstream, exacerbating salt water intrusion, accelerating rates of deltaic loss and river bank erosion and threatening the high productivity and long term stability of the Mekong Delta.
All these developments renders the Delta unable to fulfil its important ecological services and leads to increasing challenges for planners and authorities to ensure a sustainable management of the region. In this context, an important aspect to support planning processes is the availability of a consistent and up-to-date data- and knowledge base on the most relevant key themes as well as operational instruments for the effective communication and distribution of information.
Objectives
The overall objective of the Catch-Mekong project is to provide innovative research and technologies for a sustainable and transboundary management of the natural water and land resources in the Mekong Delta.
More specifically, the project focuses on the following objectives:
- Establishment of a profound data and information base for scientists, planners, and decision makers to help address development challenges
- Filling knowledge gaps in the key themes water availability, saltwater intrusion, land use, river morphology, and coastal erosion.
- Transfer of know-how and technology, through the development of innovative hydrologic sensor technologies and measurement stations
- Support planning and decision making progresses by increasing the capacity for data sharing and communication through novel web-based information technology
Approach
The Catch-Mekong project focuses on two of the most pressing topics in the Mekong Delta, i.e. saltwater intrusion and long-term delta system stability under consideration of upstream developments.
A German consortium of four research institutes and two companies jointly works together with a Vietnamese consortium covering the fields of hydrology,
hydraulic engineering, remote sensing, geography, sensor development, and information technology.
The core project’s work comprises multidisciplinary research activities on the topics of saltwater intrusion and morphological stability of the Mekong Delta.
Hydrodynamics and sediment dynamics in the Mekong Basin
Changes in hydrology for the entire Mekong river system as result of upstream developments related to climate, land use dynamics, and hydropower dams are assessed as prerequisite for analysing the down-stream consequences in the Mekong Delta. Therefore, research activities in the field of remote sensing for assessing land use and water quality parameters in the Mekong Basin will be combined with large scale hydrological modelling. The principle goal of the modelling at basin scale is the quantification of water discharge and sediment loads in the Mekong Delta at current state and under different boundary conditions.
Saltwater intrusion in the Mekong-Delta
To get a deeper understanding of the impacts of upstream developments and other external effects on saltwater intrusion in the Mekong Delta, a large scale hydrodynamic model for the Mekong Delta will be calibrated to allow comprehensive simulations on saltwater intrusion dynamic. Beside the modelling work also the interaction between surface water and ground water aquifers in coastal zones will be investigated. Therefore multiple measurement sites in river channels and ground water wells will be implemented.
In this process electric conductivity, stable isotopes, will be monitored to identify the mechanisms of groundwater regeneration.
In addition outcomes from hydrodynamic models will be combined with information on land use patterns derived from dense satellite data time series to evaluate the impacts of salinization on agriculture in the Delta.
Bed-load transport, river bank/coastal morphology, and sea level rise in the Mekong Delta
Acquired data from satellites, extensive measurement campaigns, and custom-built hydrological measurement stations will be used in numerical models to quantify the river bed-load transport budget for certain river passages and to assess the impacts of continuously reducing sediment loads due to hydropower dams and sand mining on the river bed. Furthermore satellite data will be used to gain a clearer understanding on erosion processes and coastal stability in the Mekong Delta.
Mekong Knowledge Hub
The derived data and information form important building blocks for the decision making process by local to national administrative bodies. Instruments for the effective management, query, visualisation, and distribution of information and findings of the project to all participants and other important players, stakeholders, and decision makers in the region are therefore needed. In view of this the project developes and sets up a web-based information system, the so called „Mekong Knowledge Hub“. All project results are integrated into the system and made available to both local and international actors.
Contact
For further information, please contact:
Juliane Huth
German Aerospace Center (DLR),
Earth Observation Center (EOC)
German Remote Sensing Data Center (DFD)
Oberpfaffenhofen,
82234 Wessling
Germany