## 3 Results  
### Analysis of the Geomorphological Parameters of the Area  
In order to better understand the evolution of the forest area change and its dependence on the features of the land surface, a study of the links with the topographical and geomorphological parameters of the area was conducted. This helps answer the \"where\" question when studying the expansion/diminishing of forest areas. It also helps determine the links between these topographic parameters, which determine the attractiveness of the territory for agricultural activities and, historically, had the greatest influence on the change in forest areas, and the changes in the area of forest cover. By applying GIS software, using the cloud of LIDAR points and the IDW modelling algorithm, a raster model of the altitudes of the land's surface was created (digital terrain model--DTM). Its spatial resolution is 3.14 \(\times\) 3.14. A model of surface slopes (in degrees) was created from this model. Next, the slope was reclassified according to the orientation in relation to the cardinal directions (directions: north, northeast, east, southeast, south, southwest, west, northwest). The obtained geomorphological parameters were reclassified and converted into tables. A statistical analysis was performed using the obtained data. All quantitative land surface parameters processed with GIS software and expressed by raster maps are presented in Figure 6.  
It can be seen in Figure 6a,b that the altitudes in Jurbarkas District change from 8 m to 92 m, from east to west. The altitudes vary quite evenly, with the lowest points in the eastern part and along the Nemunas River and the highest points in the western part of the district. It can be seen from Figure 6c that, bigger slopes of the territories are concentrated on the banks of the rivers; the biggest slopes are on the banks of the Nemunas River, in the southern part of the district. Figure 6d shows that the majority of the area is occupied by areas with a very low slope, respectively:  
\(0^{\circ}\)-\(0.78^{\circ}\approx 58\%\)  
\(0.78^{\circ}\)-\(2.59^{\circ}\approx 31\%\)  
\(2.59^{\circ}\)-\(5.18^{\circ}\approx 6\%\)  
\(5.18^{\circ}\)-\(8.55^{\circ}\approx 2\%\)  
Determination of the slope of the land surface favorable for agricultural activity (small and moderate) of the entire area (as a percentage) was carried out. Areas with a low and moderate slope of \(0^{\circ}\)-\(13^{\circ}\) are assigned to a single interval (a slope gradient of up to 13 degrees can be considered suitable for farming). The remaining slope, which is not particularly favorable for agricultural activities, is divided into intervals. The intervals have been chosen based on the difficulty of cultivating the land and the tendency for erosion (Figure 6g). Figure 6: Geomorphological parameters of Jurbarkas District: (**a**) distribution of altitudes of the land surface, expressed in meters; (**b**) shares of the land surface slopes, divided into intervals, of the territory of the entire district (intervals of the slopes are given in the legend of the chart; the ratio of the area occupied by the slopes to the area of the entire district is presented as a percentage); (**c**) distribution of slopes of the land surface (intervals of slopes are given in the legend); (**d**) shares of the slopes of the land surface, divided into intervals, of the territory of the entire district (intervals of slopes are given in the legend of the chart; the ratio of the area occupied by the slopes to the area of the entire district is presented as a percentage); (**e**) aspect of the earth surface; (**f**) shares of slopes with respect to the cardinal directions of the total area of the district; (**g**) expression of the slope of the area in degrees.