## 4 Discussion  
This study proposed an approach that highlights how surveying equipment, photogrammetric equipment (UAVs, Unmanned Aerial Vehicles), and GIS software can contribute to the creation of a complete workflow that can be ensured in an extremely short time (almost real-time) to obtain useful information for the prevention, simulation, and rapid intervention in the case of floods. Both the equipment and the software used belong to the entry-level-medium category from the point of view of costs. However, the obtained results allow the generation of extremely valuable maps and information for those who are responsible for the intervention in the flood study area. The use of technology was chosen as an alternative to the use of satellite images taking into account the fact that, for the type of images of phenomena that extend over a longer period of time, it is recommended to use satellite images, but for ongoing phenomena, it is more difficult to use these images satellite images for Romania and similar countries that do not invest in emerging technologies. This means that, in such regions, the specialists have exclusively available commercial satellite images with resolutions lower than 0.5 m, which do not provide the clarity and precision necessary for the most accurate modeling of the terrain. In other words, for simulation and forecasting, it is better to use satellite images, because they can look at a more general framework (the entirety of the Somes River, in our case), but for punctual emergency intervention, to see the amount and area of the affected areas, it is recommended to use UAV equipment. The type of revisiting of the satellites must also be considered, which sometimes can take 5-10 days, so that the provision of exclusive information based on satellite images from such sensors, for a phenomenon that happens in a few hours, can be late. Thus, we refer to a commercial resolution of 1m, a maximum of 0.5 m compared to 2-3 cm/pixel with the drone, which allows obtaining DEMs much more precisely and in a more accurate way. One of the advantages of using UAV images is that they can also be taken on days with a lot of clouds, by flying below the cloud ceiling, which is simply impossible for satellite  
Figure 13: The last phase of the flood. Greater depths are shown in dark blue and shallower depths in light blue. images. Another aspect related to costs is also important: the processing and interpretation of satellite images involve better-trained specialists; thus, it requires higher costs [49; 50; 51; 52]. Of course, in addition to the advantages presented related to obtaining images using UAV compared to satellites, there are also several limitations and disadvantages, which are listed below:  
* The obligation to obtain flight authorization from relevant institutions makes flying in certain areas difficult, or even extremely limited, with the need for special flight permits. * The limited flight ceiling, for example, in the study area, it was limited by law to a maximum of 120 m above the ground. * For weather conditions related to wind, it is recommended that UAV flights be conducted in wind conditions of a maximum of 12-18 mph. * The take-off and landing area must be relatively flat, respecting distances from crowds of people and without endangering people not involved in the UAV flight. * Cold weather can be an impediment, given that the flight takes place in cold weather conditions that do not comply with the technical specifications of the UAV equipment (less than \(-5\) degrees Celsius). * The position of the Sun can affect the quality of certain photos, depending on the location of the drone's photo sensor. * For the legal operation of UAV flights, qualified personnel with pilot licenses are required. * Certain areas (waters and lakes) present particularities of reflectivity that make it very difficult or even impossible to process images in specialized software (Pix4D, AgiSoft, etc.). First, an orthorectified image was obtained by processing the images obtained from the UAV flights.