LOSS OF RIVER NATURALNESS – CAUSES AND CASE

The economic growth of lowland areas is closely related to water management, with the development of valley areas limited by local hydrological conditions. The water retention shaped by hydro-technical structures enables the subsequent use of water for flood protection, agricultural, industrial, fire-fighting, energy, or recreational purposes, conditioning the potential development opportunities of the region. Over the years, there have been different approaches to the exploitation of water resources – from total subordination of nature by man to the development of sustainable solutions. However, to utilise the potential of rivers, channels and valleys were subjected to regulation, which in some cases provided immediate economic benefits, but in the long-term, deprived the river of its natural qualities, inhibiting its ability to self-purification morphodynamic processes. The water runoff acceleration as a result of channel straightening and concreting, combined with the narrowing of river valleys, led to a progressive increase in flood risk. As observed, over the years, such rivers increased the flood problem, oppositely to intentions. In response to deteriorating hydromorphological conditions, a variety of mitigation measures have been undertaken, which can be broadly termed as river restoration. The article presents the most common causes leading to the loss of naturalness, one of the most significant environmental effects. As demonstrated, most often, the loss of naturalness of water occurs through the influence of several factors, although in individual cases, it is possible to recognise one of them as the main threat source