STRUCTURAL FEATURES OF A WATER INTAKE FACILITY FOR MOUNTAIN AND SUBMOUNTAIN RIVERS

Introduction: The rate of urbanization is currently high. Therefore, it is important to use various elements and devices for water intake and water supply. Purpose of the study: We aimed to consider and analyze the structural features of a water intake facility for mountain and submountain rivers. Methods: In the course of the study, we used the synergistic research principle and statistical analysis. We analyzed the types of water supply networks at mountain rivers and identified the features of water intakes at water sources of this type. Results: A description of water intake features under flood conditions in the Amur Region, exemplified by the Bureya River, was obtained. The mountain rivers have an uneven runoff, which fluctuates not only throughout the year but also throughout the day. The water supply of the mountain and submountain areas shapes the idea of hydrological control over the regime of the mountain rivers. This paper will help to study changes in the average water inflow over the years and thus facilitate an accurate and detailed description of the water inflow characteristics in the Bureya reservoir when planning the water-energy modes of the hydroelectric power plant.

Estimation of energy dissipation in step-pool reaches of mountain river - a field investigation

The bed of the step-pool rivers is adapted to the flow conditions in terms of the topographic position and the steep slope of the path in such a way to dissipate the water energy, along the river. The beds of these rivers is sinusoidal like the meander rivers. However, as the river banks are mostly rocky in mountainous areas and the erosion in these areas is less, the bed fluctuation of these reaches is mainly vertical. When the water flow streams from the step crest into the pool, most of the water energy dissipates. In addition to the height difference, other factors contribute to the energy dissipation in the step pool reaches. The present study examines the energy dissipation by determining its effective factors, including step height (H), step length (L), hydraulic radius (R), sediment material diameter (d84), velocity in the step (V), etc. by field measurements in three reaches of mountain rivers. In the same vein, an equation is provided to estimate energy dissipation in the step pool reaches, by considering measurable effective parameters.

Patterns of Difference between Physical and 1-D Calibrated Effective Roughness Parameters in Mountain Rivers

Due to the presence of boulders and different morphologies, mountain rivers contain various resistance sources. To correctly simulate river flow using 1-D hydrodynamic models, an accurate estimation of the flow resistance is required. In this article, a comparison between the physical roughness parameter (PRP) and effective roughness coefficient (ERC) is presented for three of the most typical morphological configurations in mountain rivers: cascade, step-pool, and plane-bed. The PRP and its variation were obtained through multiple measurements of field variables and an uncertainty analysis, while the ERC range was derived with a GLUE procedure implemented in HEC-RAS, a 1-D hydrodynamic model. In the GLUE experiments, two modes of the Representative Friction Slope Method (RFSM) between two cross-sections were tested, including the variation in the roughness parameter. The results revealed that the RFSM effect was limited to low flows in cascade and step-pool. Moreover, when HEC-RAS selected the RSFM, only acceptable results were presented for plane-bed. The difference between ERC and PRP depended on the flow magnitude and the morphology, and as shown in this study, when the flow increased, the ERC and PRP ranges approached each other and even overlapped in cascade and step-pool. This research aimed to improve the roughness value selection process in a 1-D model given the importance of this parameter in the predictability of the results. In addition, a comparison was presented between the results obtained with the numerical model and the values calculated with the field measurements

Spatial-temporal distribution of birds in the northern macroslope of the Kyrgyz mountain ridge (Tien Shan)

Based on the results of our analysis, a classification of bird species of the Kyrgyz mountain ridge (Northern Tien Shan) was compiled according to their preference for habitats and occurrence throughout the year. The program of factorial classification used for this unites species according to the maximum similarity in their distribution and stay in an unspecified number of clusters. In total, 4 supertypes and 12 types of preferences have been identified along the Kyrgyz ridge. In the supertype of birds that prefer undeveloped areas, 6 types were distinguished, namely, the species choosing: 1 – high mountains, 2 – high and medium mountains, 3 – medium mountains, 4 – medium mountains and foothills, 5 – foothills, and 6 – found at all heights. The supertype of birds preferring built-up areas is represented by one type only: the species preferring foothill sheaths and villages, and the supertype of birds preferring rivers and their banks is represented by four types, namely, the species preferring: high-mountain rivers in the summer and autumn; high-altitude and mid-mountain rivers in the spring and summer; mid-mountain rivers in the autumn; and foothill rivers in the first half of the summer. The supertype uniting species found in all habitats is represented by one type of preference, namely, found throughout the whole year. It is shown that of the 154 recorded bird species, most were found in undeveloped habitats, and 6 and 12 times less were in built-up areas and rivers, including their banks. In undeveloped areas, most bird species prefer high- and mid-mountainous landscapes and half as many prefer foothill landscapes. In residential landscapes, most species tend to the foothills, and among rivers, they prefer high-altitude and mid-mountain areas. At to the seasons, the maximum number of species was recorded in the spring-summer and summer periods.