A forest fire prevention reservoir and storage capacity calculation method

Abstract

The present invention discloses a forest fire prevention reservoir and a storage capacity calculation method, comprising a dam located near a forest river channel, wherein the forest fire prevention reservoir is formed after the dam is filled with water, and the storage capacity below the fire prevention limit water level h2 and above the fire prevention dead water level h1 is the fire prevention storage capacity V; a water transmission pipeline network is arranged in a forest fire prevention range downstream of the forest fire prevention reservoir, the water inlet end of the water transmission pipeline network is connected to the forest fire prevention reservoir, and water outlet points are arranged at various locations of the pipeline; a pump station is arranged in a forest fire prevention range upstream of the forest fire prevention reservoir, the water pumping end of the pump station is connected to the forest fire prevention reservoir through a pipeline, and the water outlet end of the pump station is connected to a water tank on a high ground in the area through a pipeline, and a water transmission pipeline network is also arranged in the forest fire prevention range upstream of the forest fire prevention reservoir, and the water inlet end of the water transmission pipeline network is connected to the water tank; the present invention solves the problems of water shortage and water transmission difficulties due to inconvenient transportation near the fire point when a forest fire occurs, improves the speed and effect of forest fire extinguishing, and reduces fire losses.

Description

Technical Field

[0001] The present invention relates to the technical field of forest fire prevention, in particular to a forest fire prevention reservoir and a storage capacity calculation method. Background Art

[0002] Forest fires continue to occur frequently and are highly unpredictable. They often occur in inaccessible areas, resulting in large fires that spread rapidly. Firefighters and standard firefighting equipment often struggle to reach and effectively extinguish the fires, making rescue operations challenging. These fires not only burn vast tracts of forest and timber storage areas, but also destroy numerous buildings and homes, causing casualties among local residents and firefighters, resulting in significant losses to the nation's forest resources and the lives and property of the people. Currently, direct and indirect firefighting methods, aerial firefighting, and artificial rainfall are commonly used to fight forest fires. Among these direct firefighting methods, water extinguishing is the most common, convenient, inexpensive, and effective. However, because forest fires often occur in dry seasons and remote locations, the effectiveness of water-based firefighting tools such as helicopters and fire trucks is limited by factors such as the availability of water in tributaries, inaccessible water transport capacity, and round-trip time. The volume of water from firefighting sources and the method of its transportation play a crucial role in firefighting effectiveness. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a forest fire prevention reservoir and storage capacity calculation method to solve the problems of water shortage and difficulty in water supply near the fire point when a forest fire occurs, improve the speed and effect of forest fire extinguishing, and reduce fire losses.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a forest fire prevention reservoir, including a dam located near a forest river, after the dam is filled with water, a forest fire prevention reservoir is formed, and the storage capacity below the fire limit water level h2 and above the fire dead water level h1 is the fire prevention storage capacity V; a water supply network is set up in the forest fire prevention range downstream of the forest fire prevention reservoir, the water inlet end of the water supply network is connected to the forest fire prevention reservoir, and water outlet points are set at various places in the pipeline; a pump station is set up in the forest fire prevention range upstream of the forest fire prevention reservoir, the water pumping end of the pump station is connected to the forest fire prevention reservoir through a pipeline, and the water outlet end of the pump station is connected to the water tank on the regional high ground through a pipeline, and a water supply network is also set up in the forest fire prevention range upstream of the forest fire prevention reservoir, and the water inlet end of the water supply network is connected to the water tank.

[0005] Preferably, a valve well is provided near the dam in the water supply network, and a valve is provided in the valve well for controlling outflow.

[0006] Preferably, the method for calculating the fire prevention storage capacity of the forest fire prevention reservoir comprises the following steps:

[0007] S1: Lay a water pipeline network from the forest fire prevention reservoir to the fire-prone forest areas, and reserve multiple water outlets according to the design to form a forest fire prevention water supply system;

[0008] S2: First, connect adjacent water outlets with straight lines to form several triangles. Then, draw perpendicular bisectors for each side of each triangle. These perpendicular bisectors are connected to each other to divide the forest area covered by the water outlets into several polygons. The polygons at the boundary of the covered area are bounded by the boundary of the covered area. Each polygon has a water outlet, so that any position within the polygon is the closest to the water outlet of the polygon.

[0009] S3: Extinguishing forest fires within polygonal coverage areas at different locations requires consideration of various factors, including the probability of multiple fires occurring simultaneously in forests with different topographic structures; the coefficients of forest areas composed of different proportions of tree, shrub, and herbaceous vegetation; the loss coefficients of reservoir water flowing through different water distribution networks composed of water distribution networks, reservoirs, and outlet points; and the efficiency of the combined linkage between the upper and lower reservoirs of a pumped-storage power station when fire prevention storage capacity is provided.

[0010] S4: The water volume sprayed at each outlet point within each polygon to extinguish different types of vegetation fires represents the comprehensive water demand for fire extinguishing within the polygon area. Finally, the total water demand for fire extinguishing within the coverage area is calculated based on the comprehensive fire flow rate per unit area, fire extinguishing time, and area size. Various influencing factors are comprehensively considered to estimate the fire protection storage capacity. The fire protection storage capacity V within the coverage area is calculated as follows:

[0011]

[0012] Where:

[0013] A i is the area of each polygon in the area covered by the water outlet, m 2 ;

[0014] q is the comprehensive fire flow rate that can suppress the development of fire per unit area in the coverage area, (m 3 / s) / m 2 ;t i is the time, s, to extinguish a fire in a polygonal area with different sizes, terrain trends, and vegetation types; α is the expected probability coefficient. The probability of multiple fires occurring simultaneously in forest areas with different terrain structures varies, and the value needs to be evaluated based on actual conditions.

[0015] β is the vegetation type coefficient. The coefficient values of forest areas composed of different proportions of trees, shrubs, and herbs are different and need to be determined based on actual measurements.

[0016] θ is the effective utilization coefficient of the reservoir water when it flows through the water transmission network, the reservoir, and the water outlet. The effective utilization coefficient value varies for different water transmission networks, and is generally in the range of 0.8-1.0;

[0017] λ is the linkage coefficient between the two reservoirs. When both the upper and lower reservoirs of a pumped-storage power station are equipped with fire-proof storage capacity, the value is determined by comprehensively considering the efficiency of the linkage between the two reservoirs. For non-pumped-storage power stations, the value is 1.

[0018] Preferably, for an existing reservoir, it further comprises the following steps:

[0019] S5: The reservoir capacity is calculated based on the reservoir drawings. The area enclosed by several contour lines above the dam site is measured on a river topography cross-section map of appropriate scale. The reservoir volume between adjacent contour lines is calculated using the average area method and then summarized and summed as shown in the following formula (1-2);

[0020]

[0021] Where:

[0022] A n and A n+1 are the areas enclosed by adjacent contour lines, m 2 ;

[0023] △h is the distance between two adjacent contour lines, m;

[0024] S6: When the △h division is smaller, the V calculation is more accurate. When △h is infinite, the corresponding reservoir capacity can be accurately calculated according to the corresponding reservoir area of each elevation, and the reservoir water level and reservoir area curve, as well as the reservoir water level and reservoir capacity relationship curve can be determined.

[0025] S7: According to the above formula (1-1), V can be obtained 防火 , then formulate the water intake elevation and determine the fire dead water level H 1， Draw horizontal lines to intersect the HF curve and HV curve respectively, and draw vertical lines to obtain the water level area F1 corresponding to the dead water level and the fire dead storage capacity V1; V1+V 防火 =V2, V2 can be found on the horizontal axis. By drawing a vertical line to intersect the HV curve, and then drawing a horizontal line to intersect the HF curve and the vertical axis, we can obtain the fire prevention limit water level H2 and the corresponding water level area F2; the storage capacity between the fire prevention dead water level H1 and the fire prevention limit water level H2 is the fire prevention storage capacity, that is, the storage capacity part represented by V in the figure; by formulating multiple water intake elevations, the above method can be used to obtain multiple fire prevention limit water levels and reservoir intervals where the fire prevention storage capacity is located. Taking into account the minimization of the impact on the original power generation, flood control and other benefits of the reservoir, the most reasonable fire prevention storage capacity interval is selected.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention proposes concepts such as forest fire prevention reservoirs, fire prevention storage capacity, and fire prevention limit water levels, combining the concepts of water conservancy projects with fire protection projects, and promoting interdisciplinary and integrated innovation. At the same time, the present invention focuses on being applied to forests in covered areas prone to fires based on actual conditions, solving the most critical water source problem in forest fire fighting, and changing the cumbersome process of traditional firefighters handling forest fire fighting and reconstructing fire hose channels. While controlling fire fighting, it is supplemented by a more convenient, more sufficient, more efficient, and safer manual fire fighting method, which can not only protect green forest resources but also reduce the danger of firefighters' work to a certain extent and reduce casualty rates.

[0028] 2. Wide coverage: Through the coordination of hydraulic structures and pipe network facilities, the entire spatial area of the mountain forest can be covered, and water resources are uniformly and intensively distributed, which is conducive to fully and efficiently exerting the efficiency of fire extinguishing.

[0029] 3. Provide water proximity: When a fire occurs outside the coverage area of the fire prevention reservoir, it will be activated according to the fire occurring in the adjacent covered polygonal area, providing water proximity for firefighters to deal with the fire point, reducing the need to rebuild the fire extinguishing water source channel and extinguishing the fire in time.

[0030] 4. Fast response speed: The present invention is conducive to the combination of sensor early warning + information system alarm, automatic water discharge + manual control, which is conducive to timely extinguishing fires from the source of small flames and controlling the expansion of fire.

[0031] 5. Scientific management: Point-like distribution of water outlets + grid management of coverage areas. Through pre-set plan process management, water supply from the pipe network is controlled scientifically, reasonably and orderly, meeting fire protection requirements while saving water resources;

[0032] 6. Save fire protection investment costs: The present invention combines existing rivers, lakes and pumped reservoirs to avoid the reinvestment of engineering costs such as re-excavation, pouring, and anti-seepage.

[0033] 7. Quantitative design of fire prevention storage capacity: This invention uses calculation method formulas to accurately calculate the required fire prevention storage capacity according to the protection area, providing a theoretical basis for the establishment of forest fire prevention reservoirs.

[0034] 8. Reasonable selection of fireproof storage capacity intervals: By proposing multiple water intake elevations, multiple fireproof limit water levels and reservoir intervals where fireproof storage capacity is located are obtained according to the calculation method. Considering minimizing the impact on the original power generation, flood control and other benefits of the reservoir, the most reasonable fireproof storage capacity interval is selected. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a structural diagram of a forest fire prevention reservoir;

[0036] Figure 2This is a schematic diagram of a method for calculating forest fire storage capacity;

[0037] Figure 3 It is a curve diagram of the relationship between water level and storage capacity, and water level and reservoir area of a certain reservoir;

[0038] Figure 4 This is a schematic diagram of fire prevention characteristic water level and reservoir capacity division;

[0039] Figure 5 This is the relationship curve between the water level and storage capacity of ZS reservoir. DETAILED DESCRIPTION

[0040] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figure 1 As shown, a forest fire prevention reservoir includes a dam 1 located near a forest river. After the dam 1 stores water, a forest fire prevention reservoir 2 is formed. The storage capacity below the fire limit water level h2 and above the fire dead water level h1 is the fire prevention storage capacity V; a water supply network 3 is set in the forest fire prevention range downstream of the forest fire prevention reservoir 2, and the water inlet end of the water supply network 3 is connected to the forest fire prevention reservoir 2, and water outlet points 6 are set at various places of the pipeline; a pump station 7 is set in the forest fire prevention range upstream of the forest fire prevention reservoir 2, and the water pumping end of the pump station 7 is connected to the forest fire prevention reservoir 2 through a pipeline, and the water outlet end of the pump station 7 is connected to the water tank 8 on the high ground of the area through a pipeline. A water supply network 3 is also set in the forest fire prevention range upstream of the forest fire prevention reservoir 2, and the water inlet end of the water supply network 3 is connected to the water tank 8. In this embodiment, for forest fire prevention areas below the dead water level h1, water can flow through a water pipeline 3 under the action of gravity to various locations throughout the forest. Water outlets 6 are evenly distributed throughout the pipeline, and these outlets 6 can be equipped with various water intakes or rotating nozzles to increase the water flow rate and spray coverage. For forest fire prevention areas above the dead water level h1, a pumping station 7 is installed upstream of the reservoir to pump water to a reservoir 8 located high in the area. Water then flows through the forest under the action of gravity, achieving complete fire prevention coverage around the high ground area.

[0042] Preferably, a valve well 5 is provided near the dam 1 in the water supply network 3 , and a valve 4 is provided in the valve well 5 for controlling outflow.

[0043] Preferably, the fire prevention reservoir in the forest fire prevention reservoir capacity calculation method proposed in the present invention is located on a high ground such as a mountain top, and its water source comes from rainfall, surface runoff, the collection of surrounding rivers and lakes, or water pumping. It can be rebuilt or the upper reservoir of an existing reservoir, water storage tank, or pumped storage power station can be used. A water pipeline network is reasonably laid from the fire prevention reservoir to the mountain forest area prone to fire, and multiple water outlets are reserved according to the design to form a forest fire prevention water supply system. Based on the location of the reservoir, gravity-fed water supply is used through pipelines to extinguish fires in forest areas at low altitudes, that is, water pipes in different directions are set deep in the reservoir, and the water head and valve opening and closing are used to control the delivery of water; in forest areas at high altitudes, water is pumped by pumping stations with designed lifts to extinguish fires.

[0044] Preferably, the method for calculating the fire prevention storage capacity of the forest fire prevention reservoir comprises the following steps:

[0045] S1: Lay a water pipeline network 3 from the forest fire prevention reservoir 2 to the fire-prone forest area, and reserve multiple water outlets 6 according to the design to form a forest fire prevention water supply system;

[0046] S2: First, connect adjacent water outlets 6 with straight lines to form several triangles. Then, draw perpendicular bisectors of the sides of each triangle. After connecting these perpendicular bisectors, divide the forest area covered by the water outlets 6 into several polygons. The polygons at the boundary of the covered area are bounded by the boundary of the covered area. Each polygon contains a water outlet 6, so that any position within the polygon area is the closest to the water outlet 6 of the polygon.

[0047] S3: Extinguishing forest fires within polygonal coverage areas at different locations requires consideration of various factors, including the probability of multiple fires occurring simultaneously in forests with different topographic structures; the coefficients of forest areas composed of different proportions of tree, shrub, and herbaceous vegetation; the loss coefficients of reservoir water flowing through different water distribution networks composed of water distribution networks, reservoirs, and outlet points; and the efficiency of the combined linkage between the upper and lower reservoirs of a pumped-storage power station when fire prevention storage capacity is provided.

[0048] S4: The water volume sprayed by the water outlet 6 in each polygon to extinguish different types of vegetation fires represents the comprehensive water demand for fire extinguishing in the polygon area. Finally, the total water demand for fire extinguishing in the coverage area is calculated based on the comprehensive fire flow rate per unit area, fire extinguishing time, and area size. The fire protection storage capacity is calculated by comprehensively considering various influencing factors. The fire protection storage capacity V in the coverage area is calculated as follows:

[0049]

[0050] Where:

[0051] A i is the area of each polygon in the area covered by the water outlet, m 2 ;

[0052] q is the comprehensive fire flow rate that can suppress the development of fire per unit area in the coverage area, (m 3 / s) / m 2 ;t i is the time, s, to extinguish a fire in a polygonal area with different sizes, terrain trends, and vegetation types; α is the expected probability coefficient. The probability of multiple fires occurring simultaneously in forest areas with different terrain structures varies, and the value needs to be evaluated based on actual conditions.

[0053] β is the vegetation type coefficient. The coefficient values of forest areas composed of different proportions of trees, shrubs, and herbs are different and need to be determined based on actual measurements.

[0054] θ is the effective utilization coefficient of the reservoir water when it flows through the water transmission network, the reservoir, and the water outlet. The effective utilization coefficient value varies for different water transmission networks, and is generally in the range of 0.8-1.0;

[0055] λ is the linkage coefficient between the two reservoirs. When both the upper and lower reservoirs of a pumped-storage power station are equipped with fire-proof storage capacity, the value is determined by comprehensively considering the efficiency of the linkage between the two reservoirs. For non-pumped-storage power stations, the value is 1.

[0056] The design maximum value of the fire prevention storage capacity is the storage capacity value calculated when all water outlets covering the forest fire-prone area are activated simultaneously within a certain period of time. The cost of newly built fire prevention storage capacity and the benefits of using existing reservoir capacity for power generation, water supply, etc. are taken into consideration. Different coefficients are formulated according to the actual situation of forest fires to calculate the optimal fire prevention storage capacity value that can effectively suppress and extinguish forest fires with relatively low economic cost.

[0057] In fact, the possibility of fire occurring at all ignition-prone points in the covered area at the same time is low. According to the area warned by the early warning equipment, the water outlets within the corresponding polygon and the adjacent areas can be activated, and the water outlets in irrelevant areas can be closed to carry out fire fighting in different areas and reduce the consumption of reservoir water.

[0058] Preferably, for an existing reservoir, it further comprises the following steps:

[0059] S5: The reservoir capacity is calculated based on the reservoir drawings. The area enclosed by several contour lines above the dam site is measured on a river topography cross-section map of appropriate scale. The reservoir volume between adjacent contour lines is calculated using the average area method and then summarized and summed as shown in the following formula (1-2);

[0060]

[0061] Where:

[0062] A n and A n+1are the areas enclosed by adjacent contour lines, m 2 ;

[0063] △h is the distance between two adjacent contour lines, m;

[0064] S6: When △h is smaller, V calculation is more accurate. When △h is infinite, the corresponding reservoir capacity can be accurately calculated according to the corresponding reservoir area of each elevation, and the curve of reservoir water level and reservoir area, and the curve of reservoir water level and reservoir capacity relationship (such as the attached Figure 3 );

[0065] S7: According to the above formula (1-1), V can be obtained 防火 , then formulate the water intake elevation and determine the fire dead water level H 1， Draw horizontal lines to intersect the HF curve and HV curve respectively, and draw vertical lines to obtain the water level area F1 corresponding to the dead water level and the fire dead storage capacity V1; V1+V 防火 =V2, V2 can be found on the horizontal axis. By drawing a vertical line to intersect the HV curve, and then drawing a horizontal line to intersect the HF curve and the vertical axis, we can obtain the fire prevention limit water level H2 and the corresponding water level area F2; the storage capacity between the fire prevention dead water level H1 and the fire prevention limit water level H2 is the fire prevention storage capacity, that is, the storage capacity part represented by V in the figure; by formulating multiple water intake elevations, the above method can be used to obtain multiple fire prevention limit water levels and reservoir intervals where the fire prevention storage capacity is located. Taking into account the minimization of the impact on the original power generation, flood control and other benefits of the reservoir, the most reasonable fire prevention storage capacity interval is selected.

[0066] In general, the design idea of the forest fire prevention reservoir capacity calculation method in the present invention is: first, according to the comprehensive fire prevention reservoir capacity calculation formula that takes multiple factors into consideration, the size of the fire prevention reservoir capacity required for the coverage area is determined; then, the fire prevention dead water level is determined by formulating the elevation of multiple water intakes, and then according to formula (1-2) and supplemented by the relationship curve between reservoir water level and reservoir capacity (see Appendix Figure 3 ) One-to-one correspondence is used to obtain the fire prevention limit water level, and the optimal fire prevention characteristic water level and storage capacity are determined through multi-faceted comparisons to implement the specific design and application of forest fire prevention reservoirs.

[0067] In addition, the above-mentioned average area method is not only the basis for determining the reservoir area curve and the reservoir capacity curve, but also an approximate and simple rough algorithm. It can be used as a verification method for the fire-proof storage capacity calculation method proposed in the present invention that takes into account multiple factors and comprehensively improves it, so as to achieve the purpose of calculating the specific fire-proof storage capacity in combination with multiple factors such as the mountain terrain, reservoir area conditions, and vegetation types for a more reasonable design. The two methods are compared and verified, which can estimate the corresponding storage capacity value and meet the actual fire prevention needs.

[0068] In the present invention, fire prevention storage capacity refers to the storage capacity of the reservoir below the fire prevention limit water level and above the fire prevention dead water level. Under normal circumstances, the operating water level of a reservoir with forest fire prevention requirements shall not be lower than the fire prevention limit water level, and the fire prevention limit water level is set lower than the flood control limit water level. The fire prevention dead water level is independent of the power generation dead water level and only depends on the height of the water pipeline. It can be lower than the power generation dead water level to prevent the fire prevention storage capacity from affecting the power generation flow. The detailed characteristic water level and storage capacity division are shown in the attached Figure 4 shown.

[0069] The present invention provides an example as follows:

[0070] The ZS Reservoir primarily supplies water to the ZS Irrigation District. It is a medium-sized reservoir primarily used for agricultural irrigation and flood control, with additional benefits such as urban water supply and aquaculture. The expansion of the ZS Reservoir has improved agricultural irrigation and domestic water supply for nearby towns and irrigation areas along the route, contributing to the sustained, stable, and rapid development of the local socio-economic system. The region has a mid-subtropical semi-arid climate and is densely forested, making fires highly likely. The establishment of fire-resistant storage capacity within the ZS Reservoir will effectively prevent damage to forest resources and the lives and property of surrounding residents from fires.

[0071] According to the proposed method for calculating forest fire prevention reservoir capacity, the ZS Reservoir area is used as a reference point. A water pipeline network is rationally designed based on the fire-prone areas within its coverage area, creating a forest fire prevention water supply system consisting of multiple water outlets. A triangle is formed by connecting the water outlets in a straight line, and the intersection of these perpendicular bisectors forms a polygonal area covered by these water outlets. Water is drawn from these outlets to extinguish fires within the area.

[0072] The various influencing factors that need to be considered when extinguishing forest fires in the area covered by the ZS reservoir are as follows: ① The expected probability coefficient α, which is 0.8 based on the probability of multiple fires occurring simultaneously in the forest area according to the local topography; ② The vegetation type coefficient β, which is 0.7 based on the proportion of trees, shrubs, and herbs in the forest area; ③ The effective utilization coefficient θ of the reservoir water when it flows through the water pipeline, reservoir, and water outlet, which is 0.95 based on the designed water pipeline network; since it is not a pumped storage power station, the linkage coefficient between the two reservoirs is 1.0.

[0073] The total fire prevention area covered by the ZS reservoir is a forest with a radius of 3 kilometers, covering an area of approximately 28,260,000m 2 The regional fire extinguishing time is about 0.5 hours, and the comprehensive fire flow rate to suppress the fire development trend per unit area in the coverage area is about 0.33 (L / s) / m 2 ,

[0074] According to the calculation formula of fireproof storage capacity, the required fireproof storage capacity is about 9.02 million m 3The normal water level of ZS Reservoir is 2444.00m, and the corresponding storage capacity is 32.12 million m 3 Dead water level 2395.00m, dead reservoir capacity 3.05 million m 3 . To formulate multiple water intake elevations, according to the method proposed in this invention, Figure 5 After comprehensive comparison, the fire-prevention dead water level of ZS reservoir was selected as 2390m (e.g. Figure 5 h1), the fire limit water level is calculated to be 2417m (e.g. Figure 5 h2).

[0075] The verified flood level of ZS Reservoir is 2446.60m, and the total storage capacity is 34.94 million m 3 The total static investment of the project is RMB 1636.2235 million. According to the ratio of fireproof storage capacity to total storage capacity, the static investment of fireproof storage capacity is about RMB 422.4022 million. The water price of the operating cost of ZS Reservoir is RMB 0.973 / m 3 , the corresponding fire protection storage capacity cost is 8.7764 million yuan. Given that the ecological value of each hectare of forest is approximately 40,000 yuan, the estimated ecological value of forest protection within a 3-kilometer radius is approximately 113.04 million yuan. Comparing the two, it is clear that the benefits of fire protection from building fire protection storage capacity far outweigh its costs, making this approach technically feasible and economically sound.

[0076] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The embodiments and features in the embodiments of this application may be arbitrarily combined with each other unless they conflict. The scope of protection of the present invention shall be the technical solutions described in the claims, including equivalent alternatives to the technical features of the technical solutions described in the claims. Equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for calculating the fire prevention storage capacity of a forest fire prevention reservoir, wherein the forest fire prevention reservoir comprises a dam (1) located near a forest river, wherein the dam (1) forms a forest fire prevention reservoir (2) after water is stored, and the storage capacity below the fire prevention limit water level h2 and above the fire prevention dead water level h1 is the fire prevention storage capacity V; a water transmission pipe network (3) is provided in the forest fire prevention range downstream of the forest fire prevention reservoir (2), the water inlet end of the water transmission pipe network (3) is connected to the forest fire prevention reservoir (2), and water outlet points (6) are provided at various locations of the pipe network; a pump station (7) is provided in the forest fire prevention range upstream of the forest fire prevention reservoir (2), the water pumping end of the pump station (7) is connected to the forest fire prevention reservoir (2) through a pipe, and the water outlet end of the pump station (7) is connected to a reservoir (8) on a high ground in the region through a pipe; a water transmission pipe network (3) is also provided in the forest fire prevention range upstream of the forest fire prevention reservoir (2), and the water inlet end of the water transmission pipe network (3) is connected to the reservoir (8); and the method is characterized in that: It includes the following steps: S1: Lay a water pipe network (3) from the forest fire prevention reservoir (2) to the fire-prone forest area, and reserve multiple water outlets (6) according to the design to form a forest fire prevention water supply system; S2: First, connect the adjacent water outlets (6) with straight lines to form several triangles, then draw perpendicular bisectors of the sides of each triangle. After these perpendicular bisectors are connected, the forest area covered by the water outlet (6) is divided into several polygons. The polygons at the boundary of the covered area are bounded by the boundary of the covered area. Each polygon has a water outlet (6), so that any position in the polygon area is the shortest distance from the water outlet (6) of the polygon; S3: Extinguishing forest fires within polygonal coverage areas at different locations requires consideration of various factors, including the probability of multiple fires occurring simultaneously in forests with different topographic structures; the coefficients of forest areas composed of different proportions of tree, shrub, and herbaceous vegetation; the loss coefficients of reservoir water flowing through different water distribution networks composed of water distribution networks, reservoirs, and outlet points; and the efficiency of the combined linkage between the upper and lower reservoirs of a pumped-storage power station when fire prevention storage capacity is provided. S4: The amount of water sprayed by the water outlet (6) in each polygon to extinguish different types of vegetation fires represents the comprehensive water demand for fire extinguishing in the polygon area. Finally, the total water demand for fire extinguishing in the covered area is calculated based on the comprehensive fire flow rate per unit area, fire extinguishing time and area size, and various influencing factors are comprehensively considered to calculate the fire storage capacity. The calculation formula for the fire storage capacity V in the covered area is as follows: （1-1）； Where: A i is the area of each polygon in the area covered by the water outlet, m 2 ; q is the comprehensive fire flow rate that can suppress the development of fire per unit area in the coverage area, (m 3 / s) / m 2 ; t i Time to extinguish fire in polygonal areas of different sizes, terrain trends, and vegetation types, s; α is the expected probability coefficient. The probability of simultaneous fires at multiple points in forest areas with different terrain structures has different values, and the value needs to be evaluated based on actual conditions. β is the vegetation type coefficient. The coefficient values of forest areas composed of different proportions of trees, shrubs, and herbs are different and need to be determined based on actual measurements. θ is the effective utilization coefficient of the reservoir water when it flows through the water transmission network, the reservoir, and the water outlet. The effective utilization coefficient value varies for different water transmission networks, and is generally in the range of 0.8-1.0; λ is the linkage coefficient between the two reservoirs. When both the upper and lower reservoirs of a pumped-storage power station are equipped with fire-proof storage capacity, the value is determined by comprehensively considering the efficiency of the linkage between the two reservoirs. For non-pumped-storage power stations, the value is 1.

2. The method for calculating the fire prevention storage capacity of a forest fire prevention reservoir according to claim 1 is characterized in that: The water supply pipe network (3) is provided with a valve well (5) at a position near the dam (1), and a valve (4) is provided in the valve well (5) for controlling outflow.

3. The method for calculating the fire prevention storage capacity of a forest fire prevention reservoir according to claim 1 is characterized in that: For existing reservoirs, it also includes the following steps: S5: The reservoir capacity is calculated based on the reservoir drawings. The area enclosed by several contour lines above the dam site, measured on a cross-sectional view of the river channel at an appropriate scale, is estimated. The volume of the reservoir between adjacent contour lines is calculated using the average area method and then summed up as shown in the following formula (1-2). （1-2）； Where: A n and A n+1 are the areas enclosed by adjacent contour lines, m 2 ; △h is the distance between two adjacent contour lines, m; S6: When the △h division is smaller, the V calculation is more accurate. When △h is infinite, the corresponding reservoir capacity can be accurately calculated according to the corresponding reservoir area of each elevation, and the reservoir water level and reservoir area curve, as well as the reservoir water level and reservoir capacity relationship curve can be determined. S7: According to the above formula (1-1), V 防火 , then formulate the water intake elevation and determine the fire dead water level H 1， Draw horizontal lines to intersect the HF curve and HV curve respectively, and draw vertical lines to obtain the water level area F1 corresponding to the dead water level and the fire dead storage capacity V1; V1+V 防火 =V2, V2 can be found on the horizontal axis, and by drawing a vertical line to intersect the HV curve, and then drawing a horizontal line to intersect the HF curve and the vertical axis, we can get the fire limit water level H2 and the corresponding water level area F2; the storage capacity between the fire dead water level H1 and the fire limit water level H2 is the fire storage capacity, that is, the storage capacity part represented by V in the figure; by formulating multiple water intake elevations, multiple fire limit water levels and fire storage capacity reservoir intervals are obtained according to the above method. Taking into account the minimization of the impact on the original power generation, flood control and other benefits of the reservoir, the most reasonable fire storage capacity interval is selected.

Images