This study proposes to adopt the Hazard Analysis Critical Control Point (HACCP) approach and its seven principles to assist integrated flood management and transboundary cooperation in river basins, ...extending over more municipalities, regions, or states. Although HACCP was initially employed in the food production and processing industry to identify hazards and reduce risks throughout the production process, its principles have already been successfully applied to other sectors, such as water supply and wastewater treatment. The paper focuses (a) on the adaptation of the HACCP approach for integrated flood management, for example, for assessing the impact of planned upstream measures on downstream areas, and (b) on step 3 of the proposed Flood‐HACCP approach establishing critical limits for CCPs. For the demonstration purposes, the confluence of the Slovenian part of Drava River and its tributaries, Meža and Mislinja, is selected. Results indicate that keeping the Meža River discharge within the range of ±5% from its initial value would cause only minor local changes of flood situation within the selected case study area. On the other hand, variations to the Mislinja River discharge could change the flood situation to a greater extent and in a more diffuse way.
The complexity of flow conditions at junctions amplifies significantly with supercritical flow. It is a pronounced three-dimensional two-phased flow phenomenon, where standing waves with ...non-stationary water surface are formed. To analyse the hydrodynamic conditions at an asymmetric right-angled junction with incoming supercritical flows at Froude numbers between 2 and 12, an experimental approach was used. For a phenomenological determination of the relations between the integral parameters of incoming flows and the characteristics of standing waves at the junction area, water surface topographies for 168 scenarios at the junction were measured using non-intrusive measurement techniques. The new, phenomenologically derived equations allow for determination of location, height and extent of the main standing waves at the junction. Research results give important information on the processes and their magnitude for engineering applications.
Measuring the topography of water surfaces with conventional measurement methods is, particularly in the case of turbulent flow with strong vertical and longitudinal dynamics, a very demanding and ...challenging task. Channel confluences are important elements in river engineering, as they appear in natural and regulated river channels, torrents, as well as in numerous hydraulic structures. At confluences, especially in the case of incoming supercritical flow, turbulent three-dimensional flows occur, and a time-varying structure of waters surface. Laser scanning enables data capture with high spatial and temporal resolution, and this method is widely used nowadays. This article discusses laser scanning as a measurement method for acquiring the agitated shape of a water surface. The application of a commercial two-dimensional LIDAR device for free-water-surface acquisition is presented for two cases. In the first case the measurements were performed in a glass tank where it was possible to determine the precise reference water level. In the second case we used LIDAR with turbulent aerated flow for fluctuating free-water surface measurement. Measurements were taken in the model of supercritical confluence, where the development of standing waves leads to the phenomenon of self-aerated flow. The measurements presented in the paper were conducted for a selected discharge rates and the Froude numbers of the main and side flow channels. Measurement results are shown as surface profiles at several selected locations of confluence. This measurement method has proven to be very promising.
•Supercritical confluence flow water surface profiles were measured non-intrusively.•Laser scanner allowed measurements with high spatial and temporal resolution.•Very accurate measurements of free-water surface profiles were obtained even in cases of turbulent and aerated flows with high vertical dynamics.•Complex water surface topography was constructed from scanned profiles.•Method presents a robust solution for measuring of complex water surfaces in hydro-engineering.
Due to their retention capacity, extensive flat floodplains have a significant impact on the propagation and transformation of flood waves. The conveyance and retention capacity of an area is ...significantly influenced by land use. The paper presents results of a hydraulic analysis of the impact of land use on the run-off regime in a retention area and consequently on flood wave propagation. The land use of the retention area was simulated by hydraulic roughness. The simulations were performed for flood waves with different values of peak discharge and with two lengths of duration. A spectrum of flood waves in which the retention areas have significant impact on the propagation was considered. To isolate the impact of topographical characteristics of riparian and retention areas on the communication of water between the channel and retention area, as well as on the formation of parallel streams in the area, a theoretical modelling area with simplified geometry was used in the first phase. Conclusions based on the results of the first-phase simulations were tested on a practical case of the plain Krško–Brežiško polje, where data from field measurements as well as data from the physical model were used in the numerical calibration of the model.
The paper presents an approach to the modelling of watercourses or their sections according to and in order to determine their suitability for hydropower water use on a large scale. The method is ...based on a multi-criteria analysis approach which in addition to existing guidelines defines and describes in detail the main stages for model establishment and hydropower suitability analysis. Since hydropower planning stands in direct conflict with other ecological water-related objectives, evaluation of suitability is based on two main criteria, which are supported with the belonging criteria. The first main criterion is based on evaluation of watercourses by their attractiveness for hydropower water use; the second one on evaluation of watercourses according to their ecological state or value. To support proper determination of unknown model parameters (e.g. weights of selected criteria) the paper also presents an upgrade of general multi-criteria analysis process with a calibration stage, which can efficiently upgrade in cases when calibration data is available. The proposed method was tested and discussed on a real case study with three dislocated Slovenian Alpine watercourses, where weights of preselected criteria and some thresholds of performance functions were selected as model variables and calibrated.
The Floods Directive has brought a common denominator of flood problem affairs management to the EU but does allow differences in its implementation in the Member States, as they have different ...geographical, social, and economic conditions. The common goal is a transparent assessment of the situation and reduction or management of flood risks, wherein the Member States can independently and differently select the return periods of high water and the level of risk, which leads to different legal regimes in fl ood areas. Therefore, the spatial placement is typical of individual areas of the river basin (in a Member State, Federal State); different legal regulation may also occur in the placement of interventions in the space on the adjacent banks of an interstate watercourse, which will be shown on the border stretch of the Mura River.
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