Abstract. Ice caves can be considered an indicator of the long-term changes in the landscape. Ice volume is dynamic in the caves throughout the year, but the inter-seasonal comparison of ice dynamics might indicate change in the hydrological–climatic regime of the landscape. However, evaluating cave ice volume changes is a challenging task that requires continuous monitoring based on detailed mapping. Today, laser scanning technology is used for cryomorphology mapping to record the status of the ice with ultra-high resolution. Point clouds from individual scanning campaigns need to be localised in a unified coordinate system as a time series to evaluate the dynamics of cave ice. Here we present a selective cloud-to-cloud approach that addresses the issue of registration of single-scan missions into the unified coordinate system. We present the results of monitoring ice dynamics in the Silická ľadnica cave situated in Slovak Karst, which started in summer of 2016. The results show that the change of ice volume during the year is continuous and we can observe repeated processes of degradation and ice formation in the cave. The presented analysis of the inter-seasonal dynamics of the ice volume demonstrates that there has been a significant decrement of ice in the monitored period. However, further long-term observations are necessary to clarify the mechanisms behind this change.

The use of solar radiation in the urban environment is becoming increasingly important for the sustainable development of cities and human societies. Several factors influence the distribution of solar radiation in urban areas, including urban morphology and the physical properties of urban materials. Most of these factors can be modeled with a relatively high accuracy using 2D and 3D solar radiation models. In this paper, the r.sun and v.sun solar radiation models are used to calculate solar radiation for the city of Košice in Eastern Slovakia to assess the accuracy of both approaches for vertical surfaces frequently found in urban areas. The results were validated by pyranometer measurements. The results showed relatively good estimates by the 3D v.sun model and poor estimates by the 2D r.sun model. This can be attributed to an improper representation of vertical surfaces by a digital surface model, which has a strong impact on solar resource assessments. We found that 3D city models prepared in level of detail 2 (LoD2) are not always adequate in case of complex buildings with morphological structures, such as terraces. These cast shadows on facades especially when solar altitude is high and, thus, assessments, even by a 3D model, are inaccurate.

<p><strong>Abstract.</strong> High-resolution solar radiation modelling requires the three-dimensional geometric structure of the landscape to be respected. Currently, remote sensing methods such as laser scanning and close-range photogrammetry are most commonly used for detailed mapping. The output is detailed 3D models containing buildings, trees, relief and other landscape features. The raster approach allows modeling solar energy for relief, but it is unsuitable for landscape objects such as buildings and trees. The polygonal features vector approach is mainly designed for buildings. Our goal is to create a freely available tool for highly detailed solar radiation modelling for geometrically complex 3D landscape objects. In the paper, we present a prototype of the v3.sun module. We propose a solution of solar radiation modeling designed for all landscape features based on TIN data structure. In the paper, tests of the proposed algorithmic solution for various types of 3D data obtained from the above-mentioned collection methods are demonstrated.</p>