The evolution of hydromorphological method for river assessment RHS-PL in Poland

Ocena antropogenicznych zmian warunków morfologicznych, reżimu hydrologicznego oraz ciągłości ekosystemu, podobnie jak właściwości fizyczno-chemicznych, ma znaczenie wspierające w zgodnej z Ramową Dyrektywą Wodną ocenie stanu ekologicznego wód powierzchniowych. Wśród wielu metod oceny stanu hydromorfologicznego rzek stosowanych w Polsce jedną z bardziej popularnych jest River Habitat Survey (RHS). System ten jest wykorzystywany w naszym kraju od 1997 roku przez wiele ośrodków naukowych. W 2007 roku przygotowana została pierwsza polska wersja podręcznika do badań terenowych RHS. Od tamtego czasu metoda bardzo upowszechniła się zarówno wśród naukowców, jak i praktyków. W artykule przedstawiono przegląd najważniejszych pozycji literatury polskiej i zagranicznej dotyczących stosowania metody RHS na obszarze Polski. Dokonano syntezy informacji na temat ewolucji metody w naszym kraju, podano naukowe, jak też praktyczne przykłady jej zastosowania, wady i zalety systemu, najczęściej popełniane błędy w literaturze tematu oraz przeanalizowano RHS na tle metod badań geomorfologicznych i hydrograficznych stosowanych w Polsce.Assessment of anthropogenic changes in morphological conditions, hydrological regime and the continuity of the ecosystem, as well as in physicochemical properties, is important for the assessment of ecological conditions of surface waters consistent with the Water Framework Directive. The River Habitat Survey (RHS) is one of the many popular methods used in Poland for the assessment of hydromorphological conditions of rivers. This system has been used in Poland since 1997 by several scientific centres. In 2007, the first Polish version of the textbook on RHS fieldwork was prepared and courses related to the method were organised by the Department of Ecology and Environmental Protection, University of Life Sciences in Poznań. Since then, the method has been commonly used, both by scientists and by practitioners. By the end of 2013, 200 people were trained in the application of the RHS method. The method has been used to assess the hydromorphological status of rivers and as a complementary tool in the assessment of ecological conditions, under the Habitats Directive, with reference to habitat 3260, to assess the continuity of river ecological corridors and suitability of spawning grounds for sea trout and salmon, to assess the process and effects of renaturalization of rivers, and to assess the impact exerted by an investment on the environment (OOŚ). The research was conducted in different types of lowland, upland, and montane watercourses. Both natural watercourses and artificial channels were investigated, as well as morphologically transformed river sections. Some of the studies were conducted in protected areas (in national and landscape parks) characterized by a high degree of hydromorphological naturalness. The method proved to be useful in each of the above-mentioned types of watercourses, allowing reliable assessment, and also in the case of severely transformed rivers with an entirely artificial, concrete, trapezoidal channel and urban sections of watercourses. The paper presents a review of 100 Polish and foreign papers on the use of the RHS method in Poland. A synthesis of information on the evolution of the method in Poland was performed, scientific and practical examples of its application were presented together with advantages and disadvantages of the system, the most common mistakes made in the relevant literature, and RHS was analysed in relation to geomorphological and hydrographic research conducted in Poland. The advantages of the RHS method emphasized by many authors include its affordability, simplicity and comprehensiveness of the description of a watercourse together with a river valley at a distance of 50 m from a river bed. The major advantage consists in the assessment of hydromorphological conditions based on direct measurements performed in the field, which allows collection of current data on the real condition of river habitats