River engineering is a sub-area of hydraulic engineering and deals with the planning and implementation of the expansion, regulation and utilization of rivers as well as the prevention of damage caused by them. The focus is on river regulation (river regulation, water correction ) in order to achieve a steady and constant flow of the river. The measures differ in the upper, middle and lower reaches depending on the intended purpose.
In the upper reaches, river engineering includes the construction of torrents with riverbeds , riverbed ramps ( rough ramps ) and weirs . In the middle reaches the creation of drainage cross-sections for low water , mean water and high water, especially a uniform mean water channel through the construction of punctures , longitudinal works and parallel works as well as river straightening . Straight lines, curvatures and their transitions serve to guide a new river to be created or diverted. When the water is low, rivers can be regulated by groynes or guide dams so that a navigable channel remains. The creation of runoff profiles for floods, the construction of polders and retention basins for flood retention , and the construction of dykes including sluices for the tributaries serve to protect rivers from flooding . Structures may also be necessary to protect against ice.
When building the expansion will fascines , gabions (wire boxes with stones), sink rolls, Senkmatten, hydraulic pavement, water blocks, revetments , geotextiles , etc.. Larger rivers are made navigable and canalized for inland navigation , they then serve as waterways . The means for this are groynes , barrages , barrages and locks . Navigable rivers are also given a kilometer on the bank.
So that the river remains in its even bed, compensatory measures for bed erosion and sedimentation of bed load are necessary ( bed load management ), e.g. B. by dredging, possibly also by adding bed load. There are very different means to induce or prevent washings and buildup. In his illustrated building encyclopedia of 1868, Oskar Mothes mentions: Floating, hanging, anchor B, anchor platform, washing up, excavator , spiking, bed, blesswerk, blockwork, bridge, groyne , bush, bush, revetment , dike , ebb and ff., Icebreaker, fascine , lining walls , slope, flume , speed, Grundwase , divide dam Kolk , wreath piles, Lahne, Moder, minor boat u mill Näther, stake. ff., plantings, polders , cross-deep, Riego, slaughter , shears, sluice, silt, cabinet, stacking , etc.
Rivers also serve to supply water through bank filtration for drinking water and through direct extraction for irrigation, for the cultivation of land and as cooling water for power plants. For this purpose, suitable extraction structures ( inlet and outlet structures) are necessary. River engineering also includes the damming of rivers through weirs and dams for a wide variety of purposes, for example to generate energy in run-of- river power stations and other hydropower plants or to store water for drinking and service water supply. Rivers also serve to dispose of water by using them as receiving waters for sewage treatment plants. They drain and drain the hinterland with appropriate feed lines.
Near-natural river engineering and the consideration of nature conservation issues are gaining in importance ( renaturation ). Today rivers are no longer channeled in straight paved or even concreted channels, but are created naturally with meanders, islands and still water zones. The planting of suitable woody plants and stabilizing plants serves these needs. Alluvial forests are preserved today where they still exist.
Last but not least, river engineering deals with the calculation of runoff processes, flow rates, flow velocities, water levels, water levels and the river's energy line . The drag force of a river is calculated in order to properly secure the bed and the embankments and to prevent puddles and hegers (sand and gravel banks). The bed load and the amount of suspended matter are also calculated or researched using models. In river engineering laboratories, models are used to investigate, among other things, water movements in the course of the river and the effects of water currents on the river bed.
- Lueger: Lexicon of all technology , 2nd edition 1904