A precast dam structure includes at least two precast segments coupled together via linkages and a flow path structure. The flow path structure defines a flow path having an intake port and a draft port and is associated with at least one of the at least two precast segments. The flow path structure is configured to provide a change in flow direction, either internally or externally, from the at least one of the at least two precast segments.

The invention belongs to ecological revetments in the technical field of river ecology, which particularly involves an ecological revetment to regulate wandering rivers. The ecological revetment is composed of porous concrete-piles, ecological connecting-plates, an ecological viewing-corridor and a slope green-belt. The ecological landscape-corridor and anchor rod are placed on the upper and middle parts of the pile structure, respectively. In virtue of the innovative structure, the ecological revetment will strengthen the revetment structure, reduce the revetment settlement, prevent the revetment from moving, and enhance the overall stability of the revetment project. The ecological holes exist on the ecological connecting-plates, which is beneficial to the exchange of material and energy from the river course and the bank slope, and the holes could greatly enhance the self-cleaning capacity of the water body. Not only do the plants on the ecological viewing-corridor provide the habitats for the organisms, but also green the revetment.

A runner for a hydraulic turbine configured to reduce fish mortality. The runner includes a hub and a plurality of blades extending from the hub. Each blade includes a root connected to the hub and a tip opposite the root. Each blade further includes a leading edge opposite a trailing edge, and a ratio of a thickness of the leading edge to a diameter of the runner can range from about 0.06 to about 0.35. Further, each blade has a leading edge that is curved relative to a radial axis of the runner.

Migrating fish often want to travel between different bodies of water, which may be positioned at different heights. To overcome these heights, water passages may be used that provide a water path at a slope over which a fish is able to swim up. A compact housing is provided by allowing a water guide over which the water flow flows to rotate around an axis parallel to gravity in a helical shape. The fish lock may be provided with a resting chamber which comprises a volume of water with a low flow velocity. Sensors and a controller may be provided to control a flow rate of the water through the fish lock according to for example the type of fish passing through the fish lock and an administrator may monitor the fish lock at a distance and may be contacted in case of malfunction.

A method is provided for the artificial erosion of dammed bodies of water, wherein an average grain size distribution of sediments in the dammed body of water is determined across the ground surface of the dammed body of water. A sediment requirement for downstream water is determined, and as a result, at least one displacement of the sediments in the dammed body of water into the downstream water takes place in accordance with the sediment requirements for the downstream water. Advantageously, requirements regarding at least the quantity and grain size of the sediment for the downstream water are determined.

A method for controlling the gate based on the habitat requirement for fish overwintering in rivers. According to the characteristics of biological habitat of the river and the habitat demand of fishes during overwintering, the method specifically comprises the steps of: firstly, determining candidate fishes for ecological flow calculation though fish resources investigating and historical data, and then screening out the target fish by adopting hierarchical analysis method; Secondly, establishing a quantitative response relationship curve between target fish physiological adaptions and water temperature, obtaining ecological water level which ensures the target fish overwintering safely according to the vertical temperature distribution, and establishing the relation between water depth and discharge using hydrodynamic model; finally, setting up a gate control system including a radar water level meter in the overwintering areas and an ecological water level management system in a gate control room.

A precast dam structure includes at least two precast segments coupled together via linkages and a flow path structure. The flow path structure defines a flow path having an intake port and a draft port and is associated with at least one of the at least two precast segments. The flow path structure is configured to provide a change in flow direction, either internally or externally, from the at least one of the at least two precast segments.

Disclosed are a step-by-step paired and up-down reciprocating combined fishway and a fish passage method thereof, belonging to the technical field of fish passage facilities. The present disclosure aims to provide an efficient fish passage technology for a low-head water control project, which overcomes the defects of long construction length and low fish passage efficiency of the traditional fishway. The present disclosure includes several fishway units, a mechanical transmission system, a fish repelling system, a control system, and a recovery cableway. Under the combined action of the mechanical transmission system and the fish repelling system, the fishway units reciprocate up and down step by step to form a fish passage way. The weight of the fishway units is balanced through the rotation of coaxial eccentric wheels, and the energy consumption of the mechanical transmission system is reduced. The joint of the fishway units is achieved through embedment and sliding between a sliding slot and a slider and tangent rolling between a roller row and a partition plate. In accordance with the present disclosure, the fishway construction length can be shortened, the construction cost is saved, the influence of water conservancy and hydropower projects on river connectivity is effectively decreased, and broad engineering application prospects and important ecological and economic benefits are achieved.

A migratory fish passage arrangement arranges water flow past an obstacle upstream of the water's natural flow direction, and includes a hydraulic flow arrangement with a first intake tube from upstream of the dam from an intake point to a location downstream of the dam to a feeding point, where a fish gate allows fish to enter into an elevation tube, to enter from the feeding point in the water in the elevation tube to be transported in the elevation tube to an outlet upstream of the dam. The intake point is higher than the outlet. Also disclosed is a system to guide a migratory fish to pass a dam that includes the migratory fish passage arrangement and additionally a siphon tube from an upstream location with respect to the dam to a downstream location with respect to the dam to constitute a migratory fish return route.

An improved sensor fish with robust design and enhanced measurement capabilities. This sensor fish contains sensors for acceleration, rotation, magnetic field intensity, pressure, and temperature. A low-power microcontroller collects data from the sensors and stores up to 5 minutes of data on a non-volatile flash memory. A rechargeable battery supplies power to the sensor fish. A recovery system helps locating sensor fish. The package, when ready for use is nearly neutrally buoyant and thus mimics the behavior of an actual fish.