A dynamic fluid flow control structure is provided that allows precise control over fluid flow using a series of two or more orifices, at least one of which may be reconfigured to change its flow characteristics. A flood control system and a flood control process are provided that emulate a preset discharge profile over time. Some versions of the structure, process, and system can be used to provide controlled storm discharge patterns in a developed area that emulate the natural pre-development discharge patterns.

A dynamic fluid flow control structure is provided that allows precise control over fluid flow using a series of two or more orifices, at least one of which may be reconfigured to change its flow characteristics. A flood control system and a flood control process are provided that emulate a preset discharge profile over time. Some versions of the structure, process, and system can be used to provide controlled storm discharge patterns in a developed area that emulate the natural pre-development discharge patterns.

An optical fiber sensing system according to the present disclosure includes an optical fiber (10) provided on a water discharge gate (30) of a reservoir or in a vicinity of the water discharge gate (30), a reception unit (21) configured to receive an optical signal including a vibration pattern from the optical fiber (10), and a detection unit (22) configured to detect whether an opening amount of the water discharge gate (30) is appropriate, based on a vibration pattern included in the optical signal.

An optical fiber sensing system according to the present disclosure includes an optical fiber (10) provided on a water discharge gate (30) of a reservoir or in a vicinity of the water discharge gate (30), a reception unit (21) configured to receive an optical signal including a vibration pattern from the optical fiber (10), and a detection unit (22) configured to detect whether an opening amount of the water discharge gate (30) is appropriate, based on a vibration pattern included in the optical signal.

In order to structurally simplify a frame that is a component of a door body and to reduce required levels of manufacturing precision and assembly precision, thereby reducing a manufacturing man-hour, provided is a floating flap gate 1 installed on a road surface rs at an entrance portion of a building or an underground space. An upward swinging support portion is composed of a bottom fitting 5, a resin plate 6 configured to support a door body 4 when the door body 4 is raised, a water cut-off film 13 covering the bottom fitting 5 and the resin plate 6, a first pressing plate 14, and a second pressing plate 16. The bottom fitting 5 has a convex circular arc-shaped surface 5a. The resin plate 6 has a concave circular arc-shaped surface 6a to be mated with the convex circular arc-shaped surface 5a of the bottom fitting 5.

In order to structurally simplify a frame that is a component of a door body and to reduce required levels of manufacturing precision and assembly precision, thereby reducing a manufacturing man-hour, provided is a floating flap gate 1 installed on a road surface rs at an entrance portion of a building or an underground space. An upward swinging support portion is composed of a bottom fitting 5, a resin plate 6 configured to support a door body 4 when the door body 4 is raised, a water cut-off film 13 covering the bottom fitting 5 and the resin plate 6, a first pressing plate 14, and a second pressing plate 16. The bottom fitting 5 has a convex circular arc-shaped surface 5a. The resin plate 6 has a concave circular arc-shaped surface 6a to be mated with the convex circular arc-shaped surface 5a of the bottom fitting 5.

A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.

A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.

A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.

A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.