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This paper introduces a novel method for accurately calculating the upper biomass of single trees using Light Detection and Ranging (LiDAR) point cloud data. The proposed algorithm involves classifying the tree point cloud into two distinct ones: the trunk point cloud and the crown point cloud. Each part is then processed using specific techniques to create a 3D model and determine its volume. The trunk point cloud is segmented based on individual stems, each of which is further divided into slices that are modeled as cylinders. On the other hand, the crown point cloud is analyzed by calculating its footprint and gravity center. The footprint is further divided into angular sectors, with each being used to create a rotating surface around the vertical line passing through the gravity center. All models are represented in a matrix format, simplifying the process of minimizing and calculating the tree's upper biomass, consisting of crown biomass and trunk biomass. To validate the proposed approach, both terrestrial and airborne datasets are utilized. A comparison with existing algorithms in the literature confirms the effectiveness of the new method. For a tree dimensions estimation, the study shows that the proposed algorithm achieves an average fit between 0.01 m and 0.49 m for individual trees. The maximum absolute quantitative accuracy equals 0.49 m, and the maximum relative absolute error equals 0.29%. [ABSTRACT FROM AUTHOR]

Recreational and leisure areas play a special role. These areas mitigate or eliminate the disadvantages of living in large cities, enhance the quality of life in small towns, and support sustainability. The aim of this study was to analyze the share of recreational and leisure areas in Polish counties in 2022. In Poland, recreational and leisure areas constitute a separate land-use category in cadastral registers. Annual cadastral data from the Land and Building Register at county level (in tabular form) were the main source of data for the study. The analysis revealed that the share of recreational and leisure areas was higher in counties situated in western and south-western Poland, as well as in cities. The spatially varied influence of socioeconomic factors on the share of recreational and leisure areas in Polish counties in 2002 was determined with the use of the local Moran's I statistic and geographically weighted regression (GWR). The study confirmed that population density was significantly related to the share of recreational and leisure areas in Polish counties. The impact of the remaining socioeconomic factors associated with spatial and economic development varied across regions. The study also revealed that, in addition to the current socioeconomic determinants, the share of recreational and leisure areas in Polish counties was also influenced by historical factors and the counties' development since their establishment. [ABSTRACT FROM AUTHOR]

The development of autonomous navigation systems requires digital building models at the LoD3 level. Buildings with atypically shaped features, such as turrets, domes, and chimneys, should be selected as landmark objects in these systems. The aim of this study was to develop a method that automatically transforms segmented LiDAR (Light Detection And Ranging) point cloud to create such landmark building models. A detailed solution was developed for selected buildings that are solids of revolution. The algorithm relies on new methods for determining building axes and cross-sections. To handle the gaps in vertical cross-sections due to the absence of continuous measurement data, a new strategy for filling these gaps was proposed based on their automatic interpretation. In addition, potential points associated with building ornaments were used to improve the model. The results were presented in different stages of the modeling process in graphic models and in a matrix recording. Our work demonstrates that complicated buildings can be represented with a light and regular data structure. Further investigations are needed to estimate the constructed building model with vectorial models. [ABSTRACT FROM AUTHOR]

: This article aimed to describe the potential of outdoor tourism in Poland, with emphasis on kayaking tours. Reports and strategy documents generated by the Polish Tourism Organization (PTO), spatial data, and information about tourism operators in Poland were processed and analyzed. An analysis of geographic data and business registers revealed considerable differences across Polish regions and the absence of a sustainable tourism development strategy in Poland. The results do not justify PTO’s recommendations for promoting the development of outdoor tourism operators in selected Polish regions. The study demonstrated that in some Polish regions, the development of the tourist industry is contingent on the efforts made by local entrepreneurs, whereas other regions do not tap into their tourism potential despite ample natural resources for the development of water tourism. Entrepreneurship indicators in the outdoor tourism sector have generally increased in the last 46 years, but considerable differences are noted across Polish voivodeships. The study revealed that the development of outdoor tourism is highly fragmented and that strong local hubs of tourist activity exist at the local level. The interest in water tourism has increased markedly in the last two years because this form of active recreation promotes social distancing and can be safety practiced during the COVID-19 pandemic. The aim of this article was to describe the potential of outdoor tourism in Poland, with emphasis on kayaking tours. Reports and strategy documents generated by the Polish Tourism Organization (PTO), spatial data, and data about tourism operators in Poland were processed and analyzed. The study revealed that the development of outdoor tourism is highly fragmented and that strong local hubs of tourist activity exist at the local level. Tourists preferences for participating in kayaking tours in different voivodeships do not match the recommendations of the PTO. [ABSTRACT FROM AUTHOR]