Surface Water and Ocean Topography Mission for Water Management

The Surface Water and Ocean Topography (SWOT) is a space-borne water level estimation mission proposed by NASA and French Space Agency. With the launch of SWOT in the near future, it is expected that the limitations posed by the lack of basin wide flow measurements for flood and water management around the world will be reduced significantly. Bangladesh, being one such country facing tremendous limitations in real-time flow data availability from upstream nations, was chosen as a case study to investigate the potential of SWOT for water management. A SWOT like analogue – a space-borne altimeter named ENVISAT – was used as proxy for SWOT water elevation data. HEC-RAS simulated water level data at fine spatial spacing along the river reaches, which then allowed a direct comparison with instantaneous estimation of water level at select reaches by ENVISAT. Analysis of ENVISAT data was made as a function of season, basin type and flow regime. Overall, it was found that ENVISAT can be a reasonable predictor of water level for Bangladesh rivers. The study indicated that SWOT, will be more effective than ENVISAT for water management and flood forecasting in Bangladesh after its launch.