# Evaluation of Different Simulation Methods for Analyzing Flood Scenarios in the Danube Delta
## 4 Results
The flow area for each settlement was defined by establishing the regional limits (Figure 10). In the next step, using the water rise calculation function, the resolution of the analyzed grid was set to 5 m in both main directions, x and y. This was where the water level increase amounts, using the flooding levels established in Table 4, were also introduced. Thereby, the information corresponding to the maximum levels reached in 2010 (in the Black Sea 75 reference system) was superimposed over the digital terrain model. The application of this method corresponded to the most unfavourable \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & \multicolumn{10}{c}{**Water Level-Sulina Branch**} \\ \hline \hline \multicolumn{1}{c}{} & \multicolumn{10}{c}{**32 Scenarios**} \\ \hline \multirow{2}{*}{**Localities**} & \multicolumn{1}{c}{**Reference**} & \multirow{2}{*}{**Step 1**} & \multirow{2}{*}{**Step 2**} & \multirow{2}{*}{**Step 3**} & \multirow{2}{*}{**Step 4**} & \multirow{2}{*}{**Localities**} & \multicolumn{2}{c}{**Reference**} & \multirow{2}{*}{**Step 1**} & \multirow{2}{*}{**Step 2**} & \multirow{2}{*}{**Step 3**} & \multirow{2}{*}{**Step 4**} \\  & \multicolumn{1}{c}{**System**} & & & & & & & & & \\ \hline \multirow{2}{*}{Partizani} & (m) B875 & 2.50 & 3.10 & 3.70 & 4.32 & \multirow{2}{*}{Gorgova} & (m) B875 & 2.50 & 2.70 & 2.90 & 3.11 \\  & (m) B85 & 2.72 & 3.32 & 3.92 & 4.54 & & (m) B85 & 2.72 & 2.92 & 3.12 & 3.33 \\ \hline \multirow{2}{*}{Ilganii de Sus} & (m) B875 & 2.95 & 3.35 & 4.15 & 4.32 & \multirow{2}{*}{Mila 23} & (m) B875 & 1.75 & 2.15 & 2.55 & 2.70 \\  & (m) B85 & 3.17 & 3.57 & 4.37 & 4.54 & & (m) B85 & 1.97 & 2.37 & 2.77 & 2.92 \\ \hline \multirow{2}{*}{Vulturu} & (m) B875 & 2.25 & 2.85 & 3.45 & 3.61 & \multirow{2}{*}{Crisan} & (m) B875 & 1.60 & 1.80 & 2.00 & 2.10 \\  & (m) B85 & 2.47 & 3.07 & 3.67 & 3.83 & \multirow{2}{*}{Crisan} & (m) B85 & 1.82 & 2.02 & 2.22 & 2.32 \\ \hline \multirow{2}{*}{Maliuc} & (m) B875 & 2.25 & 2.65 & 3.05 & 3.43 & \multirow{2}{*}{Sulina} & (m) B875 & 0.75 & 0.95 & 1.15 & 1.24 \\  & (m) B85 & 2.47 & 2.87 & 3.27 & 3.65 & & (m) B85 & 0.97 & 1.17 & 1.37 & 1.46 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Sets of flooding water levels in meters with reference to the Black Sea 75 (BS75) and the Black Sea Sulina (BSS), applied to the settlements. scenario, by maintaining breaches in the flood dyke of settlements for a very long time (more than 24 h). Thus, 32 scenarios were run for the analyzed localities. The results were generated in the form of flooding maps with flooded areas for each settlement, and were largely based on the digital terrain model. GIS software was used to adapt these materials to the requirements of the hydraulic modeling software and to the size of the study area. The study area being large, the size of the files used was considerable, which made it difficult to process the data at a later stage, and to introduce geographic data into the specialized software. For the development of the hydraulic model of the Danube Delta, two types of materials were collected as cartographic support. The first type of material included the digital terrain model, and the ortho photomaps of the Danube Delta. The second type of material was less recent, being topographic maps made in 1965. These two materials were refined and processed in the first phase in GIS (ArcMAP 10.4 specialized software), to bring them into the appropriate projection system. The projection used was STEREO 70, with the reference system Black Sea 75 for elevations. Based on these materials, a contour was drawn for the delimitation of the study area, both for the hydraulic modeling and for the GIS analysis. In the case of the hydraulic modeling, the area taken into account spread over the Tulcea and Sulina branches, and in the case of the GIS analysis, the area was limited to the administrative-territorial unit of each settlement on the Sulina branch.