The Zambezi River basin is the largest river basin in Southern Africa and it is one of the main water resources in the continent providing water for human consumption, irrigation of crops as well as hydropower and is shared between eight countries in Southern Africa. The basin’s water management authorities are therefore faced with the task of making tradeoffs between the competing users and riparian countries. Expected population growth in the basin as well as prediction of increased droughts in the context of climate change make the study of basin-wide water management strategies more needed than ever. The overall aim of the project is the development of a real-time water management decision support tool for the Zambezi River basin to be used by the water resources management authorities. This will be achieved through the development of a basin-scale integrated hydrologic-economic model. The main activities will be firstly the set up of a regional-scale hydrological river basin model for the Zambezi catchment using remote sensing data as input. Real-time remote sensing data will then be assimilated to the model. An economic valuation tool for real-time adaptive, economics-driven management will be integrated to the model. Lastly, the model will be applied for real-time management issues such as reservoir management, drought management and climate change mitigation. The PhD will be carried out at DTU with field work related to data collection carried out in Zambia in collaboration with UNZA. The project will build on existing DANIDA funded activities in the Water Sector Programme in Zambia, Component 3, Support to Integrated Water Resources Management.
Project Completion Report:
Hydrological models are representations of the hydrologic cycle and are used to estimate river discharge based on meteorological inputs. They are widely used for varied applications including reservoir management, flood and drought mitigation. However, predictions from models are highly uncertain and to reduce uncertainties and improve predictions for short-term applications, current measurements of river level and discharge are often used to update models. Access to in situ data is difficult in many areas and satellite based measurements can be used instead.
One such type of satellite based measurement is radar altimetry which produces time-series of water level variations for surface water bodies such as rivers, lakes and floodplains. In this PhD study, the potential for the use of radar altimetry over rivers in hydrological applications was investigated in two areas where only limited in situ data was available: the Zambezi River basin where the operation of reservoirs could be improved with better predictions of future inflows and the Brahmaputra River which is often subject to devastating floods.
In the Zambezi, we found that many rivers with widths between 80 and 400m could be monitored with radar altimetry and that in many cases the measured water levels could be used to estimate flows even with only very limited available in situ data. Radar altimetry data was then used to update river models in the two applications and good improvements of modeled river discharge we...