Hydraulic Model

The hydraulic model for the Sava River - Sava HEC-RAS was developed for the section from the border between Slovenia and Croatia up to Belgrade and the major tributaries up to the Sava River backwaters and more. The Sava HEC-RAS is coupled with the Sava HEC-HMS model which output locations match the (lateral) inflow points of the HEC-RAS model.

The model geometry is setup on a high-resolution digital elevation data, based on the Light Detecting and Ranging (LiDAR) technology, surveyed in 2017.

Lateral structures are used within the Sava HEC-RAS to transfer flow from the mainstem model of the Sava River reach to lateral areas adjacent to the Sava River. These lateral areas are represented by storage areas and usually represent areas behind the major levees of the Sava River, retention areas, or tributary backwater areas. Overall, storage areas were used as an efficient and appropriate approach to route flow leaving the Sava River model over and/or through lateral structures to lateral areas throughout the Sava River model extent. In areas where more detailed approaches were necessary, 2D areas were used to represent these lateral areas.

In addition to developing an unsteady flow HEC-RAS model for the Sava River, special analyses of two-dimensional (2D) and levee breach capabilities are also developed and available in the model. 

Model is incorporated into the Sava Flood Forecasting and Warning System.