Zambezi Decision Support System for Climate Change

Responding to Climate Change in Mozambique – Zambezi DSS

The Zambezi River basin in southern Africa covers 1.4 Mio km² and is shared by eight countries. The most downstream country is Mozambique, where river flows strongly depend on runoff from the upstream countries. To assist Mozambican experts in assessing future water resources availability considering Climate Change, a Decision Support System (DSS) for the Zambezi basin was developed.

The DSS consists of a river basin model (RBM) and an information management system (IMS).

The RBM simulates the rainfall-runoff process in 27 sub-basins. A water allocation module serves for aggregating the runoff to the river network, as well as for simulating the impact of different types of features:

• Natural floodplains and wetlands

• Lake Niassa

• Water use (abstractions)

• Hydropower plants and reservoirs

Responding to Climate Change in Mozambique – Zambezi DSS

Decision Support System

The RBM is calibrated for historic runoff conditions 1961-1990. Future scenarios consider:

• Climate change scenarios

• Building of new dams

• Diversions for irrigation

Pre-defined or user specified scenarios analyzed with web-based DSS.

Real Time Flood Forecasting (Pilot)

Based on the DSS a pilot system developed for flood forecasting on the Zambezi river. The system is based on satellite-based precipitation observations and numerical weather predictions. The pilot system provides inflow forecasts for Cahora Bassa dam and the downstream areas.

Project Impact

The representation of reservoirs is an important aspect, as two of the world’s largest reservoirs Lake Kariba and Cahora Bassa are located on the Zambezi River. These reservoirs have a strong impact on downstream runoff