## 3 Results and Discussion  
The geometry of the river network is the next important aspect of modeling. It describes the physical characteristics of the channel and its relationship with the adjacent territory. To build a model, it is necessary to determine the structure of the river network, including nodes, sections, and connections between them. Each section of the network is characterized by the length, flow direction, and connections with neighboring sections. The most important element of the geometry is cross-sections, which describe the shape of the channel at certain points. A cross-section includes the coordinates of the points that define the profile of the river bottom and banks, as well as the parameters of the channel roughness, such as the Manning's \(n\) coefficient. Table 3, as an example, provides numerical data on the points of the right and left banks of the tributary, forming linear sections of the river on the map: columns X and Y are the spatial coordinates of the points used to construct river routes, and Chainage is the linear coordinate of the point along the route, reflecting the distance from the starting point of the section. Negative numbers do not mean errors but show that some of the points are to the left or below the specified origin. This practice is convenient when modeling and analyzing small local areas, as it simplifies calculations and makes it easier to perceive data on maps and diagrams. \begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**N**} & \multicolumn{3}{c}{**Right Bank of the Tributary**} & \multicolumn{3}{c}{**Left Bank of the Tributary**} \\ \cline{2-7}  & **X** & **Y** & **Chainage** & **X** & **Y** & **Chainage** \\ \hline  
\end{tabular}
\end{table} 
Table 3: Table of coordinates of linear sections of the river (coordinates). These data are entered into the Cross-section Editor module and are used to calculate the flow distribution across the river width (Figure 2). Figure 2 shows a map of the river bathymetry (depth), color-coded according to the depth scale from green (shallow) to blue (deep). The river routes are marked with a white line with red dots corresponding to the coordinates; for example, river inflow data were provided (Table 3). When modeling in MIKE 11, the given input data together allow for complex terrains, water flows, and hydraulic structures to be taken into account, ensuring accurate calculations of flooded areas. This makes it possible not only to predict flood zones but also to develop effective measures to protect infrastructure and prevent the negative consequences of floods [32]. To model floods on the Kurchum River and build a DEM, Sentinel-2 [23] satellite images (spatial resolution up to 10 m) were used, which made it possible to determine floodplain zones and the width of the river bed. Sentinel-1 [33] images (spatial resolution up to 5 m) for 2019-2021 showed the actual flood boundaries, which ensured model validation and adjustments of the initial data. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**N**} & \multirow{2}{*}{**Link Type**} & \multirow{2}{*}{**River Name**} & \multicolumn{2}{c}{**River Chainage**} & **No of M21 Cells** \\ \cline{3-5}  & & & **From** & **To** & \\ \hline
1 & Lateral & MARALIKHA & 90,000.000 & 101,000.000 & 26 \\ \hline
2 & Lateral & MARALIKHA & 90,000.000 & 101,000.000 & 26 \\ \hline
3 & Lateral & KUCHUM & 100,000.000 & 101,000.000 & 24 \\ \hline
4 & Lateral & KUCHUM & 112,500.000 & 116,000.000 & 9 \\ \hline
5 & Lateral & KUCHUM & 117,000.000 & 123,000.000 & 12 \\ \hline
6 & Lateral & KUCHUM & 100,000.000 & 118,000.000 & 39 \\ \hline
7 & Lateral & KUCHUM & 119,000.000 & 123,000.000 & 8 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Sections of the Kurchum River.