Multitemporal assessment of coarse sediment connectivity along a braided‐wandering river

Abstract

The article presents the postflood period coarse sediment connectivity (CSC) assessment approach on the basis of the holistic ideas of the interpretation of the long‐term CSC in river channels. Seven sets of remote sensing data (1949–2009) were used as the basic information sources to study the CSC along the braided‐wandering Belá River by using the patch‐graph approach for assessing the structural connectivity. The bar areas (patches), with 200 m direct links between them, and the attribute of a deflection angle of a link to the flow direction were parameters used to estimate the integral index of connectivity (IIC) and bar area and bar link importance indices. The higher values of the IIC fit with a well‐developed bar system. Conversely, the values of the IIC decrease because of the progressive degradation of the braided pattern. The potential functional CSC was inferred from the variability of the values obtained by the balance indices representing the balance of the channel–floodplain connectivity (B1) and the bar–bar connectivity (B2). Eight types of the potential functional CSC based on the balance indices and the deduction of processes that conditioned the channel–floodplain and in‐channel CSC linkages were identified. In order to assess the development of the braidplain pattern in terms of the structural connectivity during the study time span, the linear trendline analysis of IIC associated with flood periods was applied. On the basis of the coefficient of determination, all reaches exhibit a decreasing trend in IIC values but different response to flood periods.

The Landscape Ecology of Rivers: from Patch-Based to Spatial Network Analyses

“…2). Graph-based habitat availability analyses also proved useful for quantifying the structural connectivity and spatiotemporal variability of bar sediments in the braided-wandering Belá River, Slovakia [54]. As we discuss further in the next section, these graph-based approaches may represent a particularly important advance in quantifying the role of physical and biological connectivity not only in a spatially explicit manner, but also by facilitating the inclusion of temporal dynamics.…”

Issues of Meander Development: Land Degradation or Ecological Value? The Example of the Sajó River, Hungary

“…Another important topic to be assessed in the future would be the connectivity processes [87]. It is clear that the studied river and surrounding landscapes are connected by different processes such as nutrient transport or sediment mobilization, both of these are also conditioned by the vegetation colonization [88][89][90]. The application of modelling techniques and connectivity indexes allow us detecting how meandering is influenced by other dynamic fluxes such as agricultural fields [91] or urban areas [92] and at which level.…”

Hydromorphological evaluation of the river training impact on a multi-thread river system (Belá River, Carpathians, Slovakia)

“…During high flood discharges, there is an important geomorphological effect of the connectivity of the Belá River braidplain with the floodplain and the riparian zone. This type of hydrological connectivity of the entire river system is particularly important from a geomorphological point of view for maintaining the natural erosion–accumulation processes typical for high-energy rivers, to which the Belá clearly belongs 29 . In addition, a laterally connected braidplain with riparian forest on the floodplain can fulfil a natural flood protection function during floods (i.e.…”