![]() Surveillance is a critical component of any dengue prevention and control program. The low flood series was reversed by the flood events after the year 2004 (5 – 50-year recurrence interval), which tend to increase the river sinuosity, channel widening as well as the migration of free meanders. It caused simplification of river channel planform, mainly of the natural river segments (down to 26%). The long-term low flood magnitude series coupled with land-cover changes (increasing the built-up area and communications) during the intensive regulation period led to the simplification of river channel planform by stabilization of the erosion-accumulation processes. The intensive anthropogenic impact in the second half of the 20th century mainly affected its plan-form evolution, and resulted in channel shortening and narrowing, river sinuosity index and erosion-accumulation processes decreasing and loss of free meanders. The Hornád River in the pre-regulation period was represented by a naturally meandering river planform (45.8%) with a high occurrence of in-channel landforms, where the lateral bar area prevailed. The four evolutionary periods of morphological response were identified: a pre-regulation period of 1819 – 1948, and three regulation periods with the mutual effect of flood discharges of 1949 – 2001, 2002 – 2012, and 2013 – 2016. ![]() ![]() Based on the dataset from the 2nd (1819 – 1827) and 3rd military survey maps (1869 – 1887), aerial photos (19) and orthophoto mosaics (2002, 20) the in-channel mor-phological, as well as the land cover changes, were identified. The aim of this paper was to evaluate the morphological response to human intervention and flood events on three types of river segments (natural, regulated and water-gap) of the 72-km-long river reach of the mean-dering Hornád River in Slovakia over the last 197 years. However, there has been a significant reduction of these free meanders in the last 70 years. In the 19th century, the Hornád River in Slovakia was an unmanaged river system with well-developed free meanders. We openly release Semantic Riverscapes-the dataset we collected and processed, bridging another gap in the field. Due to simplicity, accuracy and effectiveness, this workflow is transferable and cost-effective for large-scale investigations of riverscapes and linear heritage. The results of this study can benefit urban planners in formulating riverside development policies, analyzing the perception of plans for a future scenario before an area is redeveloped, and the method can also aid relevant parties in having a macro understanding of the overall situation of the river as a basis for follow-up research. The results suggest that using this approach, rivers and surrounding landscapes can be analyzed automatically and efficiently, and the mean pixel accuracy (MPA) of the developed model is 90%, which advances state of the art. Then, the relationship between the people's subjective visual perception and the river landscape environment as seen by computers has been established. Concurrent surveys, immersive and non-immersive VR, are used to evaluate these photos, with a total of 111 participants expressing their perceptions across multiple dimensions. The approach is demonstrated with an experiment on a section of the Grand Canal in China where UAV oblique panoramic imagery has been processed using semantic segmentation for visual evaluation with an index system we designed. Addressing these challenges, this study proposes an alternative: a novel workflow for visual analysis of urban river landscapes by combining unmanned aerial vehicle (UAV) oblique photography with computer vision (CV) and virtual reality (VR). The latter only reflects the subjective perception and also entails a laborious process. The former is expensive, hindering large-scale analyses, and it is conducted only on street-level or top-down imagery. Traditional approaches for visual perception and evaluation of river landscapes adopt on-site surveys or assessments through photographs.
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