The article describes changes of relief characteristics of the Main Dune Ridge of the Curonian Spit. Investigations were carried out on the basis of repeated levelling in dynamic segments of the Main Ridge. The article also characterises relief forms of deflationary origin in accumulation of eolian formations. Investigations enabled to determine different accumulation-deflation areas in the unstable Juodkrantė–Pervalka section. Investigation results allowed the forecast of dynamic stability and development tendencies of the Main Dune Ridge. The dynamics of the dunes preconditions the distribution of plant communities in eolian formation.

The aim of this research was to conduct a comparative analysis of the precision of ground geodetic data versus the three-dimensional (3D) measurements from unmanned aerial vehicles (UAV), while establishing the impact of herbaceous vegetation on the UAV 3D model. Low (up to 0.5 m high) herbaceous vegetation can impede the establishment of the anthropogenic roughness of the surface. The identification of minor surface alterations, which enables the determination of their anthropogenic origin, is of utmost importance in archaeological investigations. Vegetation cover is regarded as one of the factors influencing the identification of such minor forms of relief. The research was conducted on the Lepelionys Mound (Prienai District Municipality, Lithuania). Ground measurements were obtained using Trimble GPS, and UAV “Inspire 1” was used for taking aerial photographs. Following the data from the ground measurements and aerial photographs, large scale surface maps were drawn and the errors in the measurement of the position of the isolines were compared. The results showed that the largest errors in the positional measurements of fixed objects were conditioned by the height of grass. Grass with a height of up to 0.1 m resulted in discrepancies of up to 0.5 m, whereas grass that was up to 0.5 m high led to discrepancies up to 1.3 m high.

Climate atlases summarize large sets of quantitative and qualitative data and are results of complex analytical cartographic work. These special geographical publications summarize long term meteorological observations, provide maps and figures which characterise different climate elements. Visual information is supplemented with explanatory texts. A lot of information on short and long term changes of climate elements were provided in published Lithuanian atlases (Atlas of Lithuanian SDR, 1981; Climate Atlas of Lithuania, 2013), as well as in prepared but unpublished Lithuanian Atlas (1989) and in upcoming new national atlas publications (National Atlas of Lithuania. 1^st part, 2014). Climate atlases has to be constantly updated to be relevant and to describe current climate conditions. Comprehensive indicators of Lithuanian climate are provided in different cartographic publications. Different time periods, various data sets and diverse cartographic data analysis tools and visualisation methods were used in these different publications.

The paper considers conditions and intensity of aeolian and dune slope transformation processes occurring in the wind-blown sand strips of the dunes of the Curonian Spit. An assessment of the intensity of aeolian processes was made based on the analysis of climatic factors and in situ observations. Transformations in aeolian relief forms were investigated based on the comparison of geodetic measurements and measurements of aerial photographs. Changes in micro-terraces of dune slopes were investigated through comparison of the results of repeated levelling and measurements of aerial photographs. The periods of weak, medium, and strong winds were distinguished, and sand moisture fluctuations affecting the beginning of aeolian processes were investigated. The wind-blown sand movements were found to start when sand moisture decreased by 2 % in the surface sand layer and by up to 5 % at a depth of 10 cm. In 2004–2016, the wind-blown sand movements affected the size of reference deflation relief forms: scarp length by 8 %, scarp width by 35 %, pothole length by 80 %, pothole width by 80 %, roll length by 17 %, roll width by 18 %, hollow length by 17 %, and hollow width by 39 %. The elementary relief forms in the leeward eastern slopes of the dunes experienced the strongest transformations. During a period of 5 months, the height of micro-terraces of the eastern slope of the Parnidis Dune changed from 0.05 to 0.64 cm. The change was related to fluctuations in precipitation intensity: in July–August 2016 the amount of precipitation increased 1.6-fold compared with the multiannual average, thus causing the change in the position of terrace ledges by 21 %.

The Curonian Spit is one of the largest Holocene sand accumulation forms, stretching along the Baltic Sea coast and belonging to the Baltic sand belt. This article deals with the dynamics of the Curonian Spit dunes in the context of global climate change. Investigations were carried out in the environs of two high dunes (Parnidis Dune and Naglis Dune) over a period of 10 years (2003–2014). Levelling of cross-sections was performed using modern geodesic devices. Wind velocities and directions were measured at meteorological stations of Klaipėda and Nida. The wind regime (number of days with winds >15 m/s) was almost at the multiannual average during the study period. Sand moisture was measured in both dunes studied, and groundwater level was measured in the environs of the Naglis Dune by using ground penetrating radar (GPR). The Naglis Dune experienced a more significant lowering (by 4–6 m) compared with the Parnidis Dune over the study period, while sand deficit was greater in the Parnidis Dune (~10,000 m3). Compared with other European sand dune systems, the Curonian Spit dunes have undergone strong degradation. The article highlights possible degradation reasons and indicates the necessity of additional investigations. Only long-term investigations can contribute to disclosing the main processes both as natural background and due to anthropogenic activities, and the devising of protection measures.