Assessing Validity of Employing Surveying Methods to Capture Data on Topography to Determine Hydrological and Topographic Parameters Essential for Selecting Locations for the Construction of Small Hydropower Plants

Renewable energy sources have begun to arouse interest worldwide. The UN Sustainable Development Agenda has defined access to affordable, reliable, sustainable and modern energy as one of its main goals. This paper contains a description of the research on the assessment of the validity of employing surveying methods to capture topographic data in order to select locations suitable for small hydropower plants. For the purpose of this study, a section of a natural watercourse with the surrounding area was measured by means of the photogrammetric method using unmanned aerial vehicles (UAVs) and, for comparison, by means of the precise positioning method using the GNSS system with the RTN kinematic technique (GNSS RTN). Publicly available measurement data from airborne laser scanning (LIDAR) were also used for the analyses. In order to assess the accuracy of the methods employed, the discrete data describing the relief were analysed, and then continuous data in raster form were analysed. The analyses were performed with the use of an automatic method of height comparison and analysis of cross-sections on DEM and DSM. In the last stage of the work, the hydrological parameters were analysed, i.e., the slope of the land and the watercourse flow values determined based on the DEM captured from various surveying methods. What is unique about this work is: (1) the use of spatial data with a high resolution acquired from UAVs to search for locations for the construction of small hydroelectric power plants and assessment of their usefulness in this regard; (2) assessment of the accuracy and quality of the hydrological and morphological parameters of the area important for the selection of the location for the construction of small hydropower plants, performed based on spatial data depicting the actual area of the land measured in the field; (3) assessment of the quality of the hydrological modelling necessary to find the location. The performed surveys and analyses allowed for the identification of the advantages and disadvantages of the surveying methods employed to capture data on the topography of land as well as indications of the optimal data source.