The scarcity of water can result in a direct conflict between the protection of aquatic resources and water use. For many agencies, environmental flow (EF) methods are essential in environmental impact assessments and in the protection of important fisheries resources. The objective of this paper is to compare selected hydrological and hydraulic methods and determine the scientifically acceptable and cost-effective way to environmental flow within a section of a mountain river with high naturalness, on the example of the Wisłoka. In this paper, environmental flow was calculated using conventional hydrological methods: Tennant’s, Tessman’s, flow duration curve and hydraulic methods, wetted perimeter method (WPM) and method based directly on ichthyofauna habitat requirements (spawn and migration). The novelty is the combined use of the hydraulic and hydrological methods which relates to flow hydraulics based directly on ichthyofauna habitat conditions. The hydraulic methods provide lower values of environmental flow in comparison with the hydrological methods. The key issue in the use of the hydraulic methods is the choice of criteria. The development of the required set of parameters while taking into account their seasonal nature shifts the method toward habitat modeling methods. However, the scope of habitat requirements of ecosystems must be defined, including the set of aquatic organisms and watercourse type before a hydraulic method may be widely used. Being generally low-cost and simple, the methods presented in this paper can be applied in the water management legislative process.

This article presents the results of laboratory tests of compaction parameters and shear strength of silty soils with and without the addition of hydraulic binder in the form of lime and/or cement. The tests were carried out on samples formed with an optimum moisture content and with 0, 3, 5, and 8% hydraulic binder added to the dry mass of the soil. The soil samples were examined after 7 and 14 days of air–water treatment without and with freeze–thaw cycles. It was found that the addition of lime and cement caused changes in the compaction parameters. This effect depended to a large extent on the type of binder, and also on the grain size composition of the tested soil. The tests showed that the shear strength and the parameters describing it, i.e., the angle of internal friction and cohesion, were high and largely depended on the type of binder and the sample treatment method, as well as its duration. The obtained results indicate that the use of hydraulic binders was an effective method of surface stabilization. Improving soil properties based on the addition of a hydraulic binder is a beneficial method for the environment from the viewpoint of sustainable development and reducing CO₂ emissions because it does not require the use of, e.g., soil replacement. Using the SHAP algorithm, it was found that normal stress, initial moisture content, and curing time of the samples were the main input features that influenced the shear strength.

This work was aimed at comparing the instream flow environment of four basic hydromorphological units of a mountain gravel-bed river: pools, runs, riffles and rapids. A survey was performed during the average flow stage on the Skawa River in southern Poland. In the 3.5 km long reach, 31 physical habitats were surveyed: eight pools, eight runs, nine riffles and seven rapids. Using Micro ADV Sontek equipment, instantaneous velocity time series components were measured at eight locations in three positions—z/h = 0.2, 0.4 and 0.6—in each unit. Turbulence descriptors—the mean components of velocity, turbulence intensities calculated as the root mean square of velocity component time series, turbulent kinetic energy TKE, Reynolds shear stresses and standard hydraulic attribute, i.e., Froude number—were estimated. Although there was a wide dispersion of the turbulence variable distributions, a standard tendency of decreased mean velocity and increased turbulence towards the bottom was observed. Most turbulence parameters—streamwise velocity, turbulence intensities, TKE and streamwise-vertical Reynolds shear stresses—reveal differences of instream flow environment between the pools, runs and riffles. In addition, the mean turbulence intensities suggested a 1:2:3:3 proportion of turbulence intensity in pools, runs, riffles and rapids, respectively. Riffles and rapids, in general, have similar turbulence values, whereas rapids are deeper and visually more energetic.

Cel pracy: Badanie dotyczy charakterystyki ruchu turbulentnego trzech podstawowych jednostek hydromorfologicznych rzeki górskiej— plosa, rynny i bystrza, na przykłądzie górskiego odcinka Skawy. Materiał i metody: Na podstawie pomiarów trzech składowych prędkości przepływu (Vx, Vy i Vz) określono wartość prędkości przepływu (Vmag), fluktuacje prędkości (RMSvmag), energię kinetyczną turbulencji (TKE) oraz stopień turbulencji (K). Badaniami objęto 8 plos, 8 rynien i 5 bystrzy, wykonując pomiary prędkosci w ośmiu pionach każdej jednostki na trzech wysokościach względnych profilu hydrometrycznego 0,2 h, 0,4 h, i 0,6 h. Wyniki i wnioski: Bezwzględne parametry opisujące zjawiska przepływu turbulentnego wyraźnie różnicują jednostki hydromorfologiczne: plosa, bystrza i rynny, natomiast względny parametr turbulencji (K) tylko odróżnia plosa od bystrzy. Intensywność turbulencji była najwyższa w bystrzach, a najniższa w plosach. Zaobserwowane rozkłady prędkości były zgodne z typowym profilem prędkości — wykazywały spadek prędkości przepływu oraz jednoczesny wzrost turbulencji w kierunku dna koryta. Spośród analizowanych jednostek, plosa charakteryzowały się największym zróżnicowaniem wewnętrznym parametrów turbulencji. Uzyskane wyniki potwierdzają, że parametry turbulencji wykazują znaczną zmienność przestrzenną zarówno w obrębie, jak i pomiędzy jednostkami hydromorfologicznymi. Zmienność tę należy uwzględniać przy projektowaniu i realizacji działań renaturyzacyjnych rzek, zwłaszcza w rzekach górskich, gdzie morfologia koryta silnie wpływa na strukturę przepływu.