Dominant Hydraulic Conditions in the 2-D Model—Vistula River from Zawichost to Słupia Nadbrzeżna

Abstract

Complexity of the natural river system, creating diversified habitat conditions, was always a focus of attention and in the presented context is addressed by the use of the 2-D modeling results. Recognizing the importance of riverbed morphological elements and identification of hydraulic parameters suitable for its description, the use of 2-D modeling and spatial relations with channel parts was presented. The section of the Vistula River Gorge of Lesser Poland was modeled, segmented according to proposed method and the results were interrelated pointing out limited diversification of narrow parts in the channel. The measurement material was collected in the summer of 2017. Data including measurements of riverbed bottom geometry, water surface position and flow, as well as data obtained from the numerical model of the terrain was used. Calculations were made using discharges with relation to the hydrology of the river’s section. The spatial joining involved data located in the individual parts of the channel and hydraulic parameters derived from the model. Channel parts were analyzed: dominating depth on wide parts of the channel were found, impact of flow was established, dynamics of water velocities and depths on mid channel bars and sandbars point them out as the most sensitive places in the whole river. Minimal width of the narrow parts of the river was found as insufficient. The advantage of proposed approach is the free access to any possible questions about hydraulic and spatial interrelationships. The results prove that spatial and contextual analysis can be used as a tool to increase usability of 2-D hydraulic model in the field of scientific purposes.