RU2569821C2 - Method of prevention of area flooding during large and local floods within catchment area of rivers, and system for its implementation - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: to prevent large floods in basin of Amur River at Far East the method and system are suggested to regulate drainage of overflow waters containing diversion channel (1), connecting Maloe Kizi Lake being part of Bolshoe Kizi Lake and locates on East shore in basin of Amur River, with water area of Tatar Strait. To prevent local floods in basin of Amur River at Far East the method and system is suggested to regulate drainage of overflow waters containing diversion channel (2), connecting Peretaski distributary on East bank in basin of Amur River with Ajsky Bay being part of Bolshoe Kizi Lake. Bottom elevation for each diversion channel (1, 2) at the place of diversion of overflow waters from the water basin is made at elevation or slightly above elevation of the normal water surface level in the water basin corresponding to average stable level observed during many years. Number of the diversion channels (1, 2) and their width (b) are accepted based on calculation of maximum possible volume of overflow water diverted from water basins meeting minimum depth (h min) of channels (1, 2).

EFFECT: invention prevents flooding of areas during large and local floods, increases efficiency of water flow regulation systems in rivers' watershed area, reduces labour intensity and material expenses during arrangement of the flow regulation systems, makes easier operation conditions of systems, minimises harm to economic activities of people, nature and environment during construction and operation of the flow regulation systems, improves ecologic situation in the flood area.

4 cl, 3 dwg

Description

The invention relates to the field of hydrology and hydraulic engineering, and in particular to methods of influencing river flows using pressureless derivative structures used to maintain a normal level of the water surface in water bodies located in the flood zone.

A known system for combating floods by regulating the flow of excess water from the river catchment area, containing a drainage pipeline network connecting the river basin and its tributaries located in the flood zone with the sea [patent GB 2379236, publ. 03/05/2003]. The pipeline network consists of a main pipeline with a slope in the direction of the sea, and additional pipelines connected along its length. The upper part of the main pipeline and its inlet are located in the basin of the main river bed, and the upper parts of the additional pipelines and their inlets are located in the basins of its tributaries. During floods, the water level in the river and its tributaries rises to the highest point, when excess water begins to flow into the pipeline network, and its flows under the influence of gravitational forces flow down the pipelines into the sea. To eliminate air congestion that impedes the normal movement of the excess water flow through the pipeline network, the system must be completely filled with water, therefore, the water level in the pipeline network is maintained at a constant level and pressure, which is controlled by measuring sensors that transmit information about the state of the system to the control center. From the control center, based on the information received from the sensors, the water flow in the pipelines is controlled by means of drain and safety valves installed on them. An additional generator is installed on the main pipeline of the network, which is capable of generating electrical energy during the period of large floods. The main disadvantages of the known flood control system are: high labor intensity and high material costs for the construction of the pipeline network, including the acquisition and installation of expensive shut-off and control equipment, measuring sensors and sensor devices necessary for the normal functioning of the system; difficult operating conditions of the pipeline network, since during the flood period it is necessary to regularly clean the river sediments, branches and tree trunks of the protective grilles installed on the inlet openings of the pipelines, and after each flood there are problems with filling the pipeline network with water to restore its operating mode; damage to economic activity, since significant areas of land go out of the turnover for the construction of the pipeline system; in the dry season, the water level in the pipelines drops to a minimum, the water remaining in them stagnates, and becomes a source of adverse environmental conditions.

Also, a known method of preventing catastrophic floods in the lowlands of the middle and lower reaches of the Yangtze River by regulating the flow of excess water on the river catchment area [patent CN 103243673, publ. 08/14/2013]. The method includes: laying a 332-kilometer connecting channel between two large lakes located in the flood zone on the southern bank of the Yangtze River, erecting dams at the inlet-outlet of the connecting channel on the lakes and laying a 528-kilometer drain channel from one of the lakes in the south direction to the sea; laying a 738-kilometer branch channel from one of the southern tributaries of the Yangtze River, located in the flood zone, into the lake, located outside the flood zone; laying a 144-kilometer branch channel from the lake, located in the flood zone on the northern bank of the Yangtze River, in a northerly direction to the sea. The main disadvantages of the known method of preventing catastrophic floods are: a large amount of excavation work when laying canals that cover vast territories in the river basin; difficult operating conditions of the canals, because during floods their banks are eroded by the water flow and destroyed, therefore, to maintain the canals in working condition, they must be constantly cleaned of river sediments, branches and tree trunks, as well as to restore washed-out banks; damage to human activities due to the fact that when digging drainage channels, a large amount of soil is extracted, which is laid along the edge of the channels, thus occupying additional areas of fertile land and preventing the flow of surface water; damage to wildlife due to the fact that the entrances and exits of the connecting channel in the lakes are blocked by dams, which are an insurmountable obstacle to fish migrating for spawning, which interferes with the reproduction of fish stock and leads to the depletion of their stocks; in the dry season, the water level in the canals drops to a minimum, as a result of which the water remaining in them stagnates, the channels become swampy and become sources of adverse environmental conditions.

As a prototype adopted a method of preventing flooding by regulating the flow of excess water in the river catchment system [patent RU 2116401, publ. July 27, 1998]. According to the method, in catchment river systems, natural reservoirs located in mountainous areas and / or create artificial reservoirs are used to receive excess water during floods, for which barriers and other low places located at some distance from the river or in the riverbed themselves are blocked by dams. Before starting work on the entire catchment area, the areas of flooding during floods are determined; on the riverbeds feeding these areas, areas for the formation of excess water runoff are identified, on which individual river flow control systems are created, for which the optimal number of temporary reservoirs intended for accumulation is determined at each site excess water, which is blocked by concrete dams with openings permeable to water and river animals, for reservoirs located on each site they calculate the parameters of the flow regulation system, in accordance with the calculated parameters at all sections of the flow formation, build individual river flow control systems, including diversion channels, thus ensuring the flow of flood waters accumulated in the river systems throughout the catchment area. The main disadvantages of this method of flood prevention are: its low efficiency due to the fact that the flow control systems are located on landlocked landlocked areas, therefore, during floods, excess water accumulates on the mainland and occupy significant land areas suitable for economic activities ; high complexity and unreasonably large material costs when installing water flow control systems and erecting concrete dams of temporary reservoirs, which are performed in hard-to-reach mountainous areas, away from the centers of the construction industry and are used only during floods; difficult operating conditions of runoff systems, since after each flood of the riverbed, reservoir, dam, drains and canals, it is necessary to clean up river sediments, branches and tree trunks, as well as restore blurred areas; damage to economic activity, since significant areas of fertile land go out of the turnover for the construction of dams and the construction of reservoirs; damage to wildlife and due to the fact that during floods, streams of excess water swiftly passing through openings in dams carry river animals along and cause damage to them; in the dry season, the water level in river channels, lakes, reservoirs and canals drops to a minimum, as a result of which the remaining water in them stagnates, swamps and becomes a source of adverse environmental conditions.

The problem to which the claimed invention is directed is to prevent flooding of territories during large-scale and local floods by increasing the efficiency of water flow control systems in the river catchment area, reducing labor costs and material costs when installing flow control systems, and facilitating the operating conditions of systems, minimizing the harm to human economic activity, wildlife and the environment during the construction and operation of regulatory systems flow, in improving the environmental situation in the flood zone.

The technical result achieved in solving this problem is the creation of a system for regulating water flow, when used, excess water during floods does not accumulate in the inland areas, but flows into natural bodies of water located below and outside the flood zone, including the sea, This design features of the drainage channels used in the system, allow during floods to maintain normal water levels in reservoirs for a long period of time, regardless of weather conditions, thus preserving the water bodies and adjacent land areas for human economic activity, among other things, the diversion channels involved in the water flow regulation system have a minimum depth and are located on accessible terrain, therefore, after water drains and in between floods the ability to use plots of land occupied by branch channels for growing fodder crops, grazing cattle and other types of economic activity, the likelihood is also eliminated s harm occupants when moving river water flows during the flooding due to the minimum depth of the branch ducts and the relatively small velocity of the water streams and the water after gathering eliminated danger of swamping and channels they do not become a source of unfavorable environmental conditions.

To obtain a technical result, a method is proposed for preventing the flooding of territories during large-scale and local floods in the river catchment area, which consists in laying channels from the water bodies located in the flood zone to drain excess water into water bodies located below and outside the flood zone, for which, on river catchment areas, areas susceptible to flooding during floods are previously identified, artificial and / or natural reservoirs are used to receive excess water d, scheduled draining canals lining places and produce estimates of its parameters. What is new is that the level mark of the bottom of each outlet channel at the place where excess water is drained from the reservoir is carried out at or slightly above the normal level of the surface of the water in the reservoir, corresponding to the average stable level observed over many years, with the bottom along the length of each the discharge channel is performed with a slope i in the direction of the downstream body of water, which allows the flow of excess water during the flood period to flow along the channel to the sea, without flooding nearby areas. It is optimal if the number of outflow channels and their width b will be taken from the calculation of the maximum possible volume of excess water discharged from water bodies, which will ensure the channel throughput and full flow of water from overflowing water bodies during the flood period with a minimum channel depth h min. At least one canal can be provided for draining excess water from a river and / or river channel and / or from a lake and / or reservoir to a downstream river bed and / or to a lake and / or reservoir and / or sea, which allows to establish a normal water level in water bodies located in the flood zone. It is permissible if along its length the drainage channel will be made in a rectilinear or curvilinear shape, depending on the topography of the area on which it is located, which does not negatively affect the mode of movement of the drained excess water. To implement the above method, a system is proposed for preventing flooding of territories during large-scale and local floods on the river catchment area, including reservoirs located in the flood zone and connected by channels for draining excess water with artificial and natural reservoirs located below and outside the flood zone. What is new is that the level mark of the bottom of each outlet channel at the place of excess water discharge from the reservoir is located at or slightly above the normal level of the surface of the water in the reservoir, corresponding to the average value of the stable level observed over many years, with the bottom along the length of each the discharge channel has a slope i in the direction of the downstream reservoir, which allows for an organized flow of excess water. The system may contain drainage channels, the number of which and their width b can be taken from the calculation of the maximum possible volume of excess water discharged from water bodies, which will allow laying channels of a minimum depth h min that do not change the terrain. Preferably, if the system will contain at least one channel configured to drain excess water from a river and / or from a river channel and / or from a lake and / or reservoir into a downstream river bed and / or into a lake and / or into a reservoir and / or at sea, as a result of which excess water will not accumulate in the inland areas, and significant areas of land will be freed from water. The drainage channels can have a straight or curved shape along the length, which does not change the mode of organized runoff of excess water.

The invention is illustrated by graphic materials, in which Fig. 1 shows a schematic layout of the outlet channels in the catchment area of the river basin, Fig. 2 shows a longitudinal profile of one of the outlet channels, and Fig. 3 shows its transverse profile.

The invention is illustrated by the example of a method for preventing flooding of the territory of the Far East during large-scale floods on the catchment surface of the middle and lower reaches of the Amur River basin, as well as during local floods on its channels and lakes. A feature of the Amur hydrological regime is a periodic rise in the level of the water surface, caused mainly by summer-autumn monsoon rains, sometimes very intense, which happened in August-October 2013. To prevent large-scale floods, a system for regulating the flow of excess water is proposed, containing a diversion channel 1, which connects Lake Mali Kizi, which is part of Lake Big Kizi, with the waters of the Tatar Strait (see Fig. 1). Big Kizi Lake is located in the Ulchi district of the Khabarovsk Territory on the eastern shore in the Amur River basin and is connected to its channel by a nearby channel. Lake Big Kizi and Lake Maloe Kizi communicating with it through the Blago Strait are located in a hollow formed as a result of volcanic activity. The bottom of both lakes, their shores and coastal zones are covered with silty sediments left over from past floods. The depth of the lakes is 3-4 meters, and the difference in water levels between the lakes and the Tatar Strait is 6 meters. From the Tatar Strait, Lake Maloe Kizi is separated by a strip of land 6-7 km wide, the lowlands of which, bordering a small hill, are covered with thickets of grass and shrubs. Fragmented volcanic rocks located under the plant layer are available for development by a bulldozer. There are at least three options for laying out drain channels 1, but the most rational of them is laying channel 1 from Lake Maloe Kizi along the valley of the Bolshoy Tabo river to the tract Tuchnoye, from where branch channel 1 is sent to Tabo Bay, located below and outside the flood zone in the water area Tatar Strait. According to this option, in the place of laying the branch channel 1, the elevation differences are minimal, and the places of other variants of laying the branch channels 1 and the slope of their bottom must be justified by the results of engineering-geological, hydrogeological and geodetic studies. A constructive feature of channels 1 is that in all cases, the bottom level mark (UD) of outlet channel 1 at the place of excess water discharge from Maloe Kizi Lake is performed at or slightly above the normal level (NU) mark of the water surface in the lake, which corresponds to the average stable level observed over many years (see figure 2). During the flood period, the water in the lake rises to the highest level (WU), at which it falls into the outlet channel 1 and begins to move along the slope i of its bottom in the direction of Tabo Bay. This position of the bottom level (UD) of the outlet channel 1 relative to the normal level (NU) of the water surface at the place where excess water is drained from the lake allows the water to completely leave the channel 1 after the flood is stopped, and thereby eliminate the risk of waterlogging, besides, it becomes possible in the intervals between floods, use the area reserved for channel 1 for growing fodder crops and grazing livestock. The required number of bypass channels 1 and their width b are taken from the calculation of the maximum possible volume of excess water during the flood period in the sections of the Amur River basin (see Figs. 1 and 3), while keeping the depth h min of the channels 1 minimum. For laying the outlet channel 1, a caterpillar bulldozer-ripper equipped with a mounted bulldozer blade and cultivating equipment is used. Using a bulldozer-ripper, first remove the fertile vegetative layer of the earth, and then loosen and move the layers of rocky soil on the surface towards the Tatar Strait or Lake Maliy Kizi, and then plan the bottom of channel 1 with simultaneous compaction. The bottom along the length of the outlet channel 1 is performed with a uniform slope i in the direction of the Tatar Strait, and depending on the terrain, channel 1 along its length can be straight or curved. The laying of branch channel 1 from lakes located in the water basin of the Amur River to the waters of the Tatar Strait is the first stage in the construction of a deep-water navigable channel connecting river and lake ports with the sea.

To prevent local floods in the Far East that occur on the channels and lakes of the middle and lower reaches of the Amur basin annually, a flow control system is proposed that includes a diversion channel 2, which connects the Peretaski channel, located on the east bank of the Amur basin, with Aysky Gulf , which is part of Lake Big Kesey (see figure 1). The water surface level in the bay is lower than in the channel, while their banks are covered with silty sediments, overgrown with reeds and reeds. A narrow strip of land about 0.5 km wide, covered with thickets of grass and shrubs, separates the Peretaski channel from Aysky Bay. Under the plant layer are pebble and small clastic volcanic rocks, available for development by a bulldozer. The number of branch channels 2 and their width b are taken from the calculation of the maximum possible volume of water during the period of local flooding in the catchment area of the Peretaski duct and adjacent areas, while maintaining a minimum depth h min of channels 2. The most rational option is to lay a branch channel 2 from the channel Drag and drop to Aysky Gulf in the place where the strip of land is the smallest. A design feature of the outlet channels 2 is that in all cases, the bottom level mark (UD) of the outlet channel 2 at the place where excess water is drained from the Peretaski duct is performed at or slightly above the normal level (NU) mark of the water surface in the duct, corresponding to an average stable level observed over many years (see figure 2). During the flood period, the water in the channel rises to the highest level (WU), enters the bypass channel 2 and begins to move along the slope i of the bottom of channel 2 in the direction of Aysky Bay. To lay out the drainage channels 2, a caterpillar bulldozer equipped with a mounted bulldozer blade is used. Using a bulldozer, remove the fertile vegetative layer of the earth, and then move the soil layers on the surface towards the Bay of Aysky, after which they plan the bottom of channel 2 with simultaneous compaction. The bottom along the length of the outlet channel 2 is performed with a uniform slope i in the direction of the bay, while, depending on the terrain, channel 2 can be linear or curved along its length.

Laying of drainage channels of the proposed design in places of excess water removal from water bodies on the catchment area of rivers exposed to flooding will allow them to stably maintain a normal water surface level and use water bodies with adjacent territories for economic needs of nearby settlements and megacities for a long period, regardless of the season and weather conditions.

The above example is used only to illustrate the possibility of carrying out the invention and in no way limits the scope of legal protection presented in its formula, while a specialist in this field of technology is relatively easy to implement other ways of implementing this technical solution.

Claims (4)

1. A way to prevent flooding of territories during large-scale and local floods on the river catchment area, which consists in laying channels from the water bodies located in the flood zone to drain excess water into water bodies located below and outside the flood zone, for which purpose in areas the catchment areas of rivers, pre-identify areas susceptible to flooding during floods, create artificial and / or use natural reservoirs to receive excess water, designate places for laying out canals and they carry out calculations of their parameters, characterized in that the level mark of the bottom of each outlet channel at the place of excess water discharge from the reservoir is performed at or slightly above the normal level of the surface of the water in the reservoir, corresponding to the average value of the stable level observed over many years, the bottom along the length of each branch channel is performed with a slope i in the direction of the downstream reservoir. 2. The method according to claim 1, characterized in that the number of outlet channels and their width b are taken from the calculation of the maximum possible volume of excess water discharged from water bodies, subject to the minimum depth h min of channels. 3. A system to prevent flooding of territories during large-scale and local floods in the river catchment area, including reservoirs located in the flood zone and connected by channels for draining excess water with artificial and natural reservoirs located below and outside the flood zone, characterized in that the mark the level of the bottom of each drainage channel at the place of removal of excess water from the reservoir is located at or slightly above the normal level of the surface of the water in the reservoir, corresponding to the average the value of the stable level observed over many years, while the bottom along the length of each branch channel has a slope i in the direction of the downstream reservoir. 4. The system according to claim 3, characterized in that it contains outflow channels, the number of which and their width b are taken from the calculation of the maximum possible volume of excess water discharged from water bodies, subject to the minimum depth h min of channels.

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