## 2 Materials and Methods
### Data Acquisition, Physio-Geographical and Climate Characteristics  
GIS geometry calculations use spatial data to deliver accurate geographical analyses and measurements. Using the GIS environment, the ArcMap 10.8, and the available data regarding the geometry of the river basins and the hydrological network, several input parameters were calculated and then inserted in the IntErO model [5; 9]. These parameters, with each graphical display, are presented in Figure 4, and include: the river basin area (F), the length of the watershed (O), the area of the bigger river basin part and the area of the smaller river basin part (Fv & Fm), the natural length of the main watercourse (Lv), the shortest distance between the fountainhead and mouth (Lm), the total length of the main watercourse with tributaries (\(\sum\)L), the length of the contours and area between the contours (Liz & f), and the river basin length measured with a series of parallel lines (Lb). The creation of the database imposes a specific management, in concordance with the necessary 22 inputs for the IntErO model. Considering the necessities of the model, a GIS database was created, complexly structured on vector and raster layers, starting from the primary database (contours, hydrography, soil, land cover, etc.) and moving to the derivate data (meteo data, digital elevation model, etc.). For the DEM-derived data, such as contour levels 100 m equidistant and the maximum and minimum elevations in each river basin, the SRTM DEM with 25 m resolution was used. The Shuttle Radar Topography Mission Digital Elevation Model (SRTM DEM) is a dataset compiled from radar data gathered during the 2000 space shuttle mission by NASA. It provides global elevation data and a three-dimensional representation of the Earth's terrain. The resolutions and precisions of the data differ, with enhanced versions  
Figure 4: Geometric input parameters extracted from GIS (display from Batin river basin). available for specific regions. The SRTM DEM (Figure 5, top) is utilized extensively for cartography, terrain analysis, hydrological modeling, and infrastructure planning. It is open to the public and has become a valuable resource for scientific and commercial applications worldwide [42]. This investigation considered the geological structure of the terrain in terms of the permeability and erodibility of rocks. The geological map for the study area necessary for the permeability was extracted from The International Hydrogeological Map of Europe, scale 1:1,500,000 (Figure 5, top middle). The International Hydrogeological Map of Europe (IHME) is a project that seeks to standardize the representation of hydrogeological data throughout Europe. It combines information from multiple sources to generate a unified map depicting aquifers, groundwater flow, quality, and other pertinent parameters. The IHME promotes data standardization and harmonization, thereby facilitating international collaboration and consistent groundwater-management practices. It supports sustainable water management, planning, and decision-making processes, serving as a valuable resource for policymakers, water resource administrators, and researchers [43]. The soil database was constructed by digitizing 1:200,000 scale maps with the SRCS ICPA-1980 (Romanian Soil Classification System), naming and updating them to the FAO UNESCO SRTS 2003 (Romanian Soil Taxonomy System) designations (Figure 5, bottom middle) [8,19]. Figure 5: Databases used in the modeling process. Corine Land Cover (CLC) is a dataset that provides information on land cover and land use across Europe. It is produced by the European Environment Agency (EEA) and provides valuable information for various applications and disciplines (Figure 5, bottom). The CLC 2018 dataset is of great importance, due to its ability to monitor and assess changes in land cover over time, aid in land management and planning decisions, contribute to biodiversity conservation efforts, support climate change research, and facilitate cross-border and international cooperation.