Developing river rehabilitation scenarios by integrating landscape and hydrodynamic modeling for the Ciliwung River in Jakarta, Indonesia

• Integrated approach couples landscape and hydrodynamic modeling.
• Modifying base point cloud data to form different scenarios for testing.
• Series of 6 scenarios ranging from land use changes to a full canal created.
• Full canal able to hold the flood waters but with potential of impacts downstream.
• Green infrastructure scenario is unable to hold the most severe floods.
• A carefully combined scenario is likely to be the best option.

Landscape visualization and modeling has progressively merged over the last decade providing ever increasing accuracy and realism. As powerful as visualized landscapes may be, there is a need to integrate them with numerical models to simulate real world dynamics, and by doing so, move beyond a purely visual evocative expression to one which is physically grounded in reality. In this paper, we present an approach that integrates landscape and hydrodynamic modeling through the modification and testing of point cloud data to assess the flooding of the Ciliwung River in Jakarta, Indonesia. We propose a series of 6 scenarios along the 40 km course of the river corridor ranging from the governments’ “normalisation” proposal to a green infrastructure scenario by our team. Through such flood simulations we have found that the severity of the floods can only be contained by implementing the extensive normalized canal that is planned, however, the scale of the intervention at hand and the possible impacts further downstream need to be carefully weighed in. Likewise, while the green infrastructure scenario can be seen as a possible alternative to flood management, it is unlikely to mitigate the effects of the most severe of floods. In reality, a careful combination of the two extreme scenarios of a new concrete channel and a green corridor will likely provide the best balance between flood mitigation and riparian restoration. The integrated modeling approach presented here provides a possible platform to further refine such a scenario into one which best caters to all stakeholders in the Bogor, Depok and Jakarta regions.