Mountain flood disaster warning method based on association manner between protection object and rainfall observatory

Abstract

To provide a mountain flood disaster alarm method for reducing a false alarm rate and an alarm leakage rate of a mountain flood disaster alarm.SOLUTION: The mountain flood disaster warning method includes step 1 of classifying all rainfall stations in an area where a protection object is located based on relative positions with the protection object, step 2 of establishing an association manner between the protection object and the rainfall stations based on a density of the rainfall stations in an upstream area of the protection object, step 3 of establishing a mountain flood disaster warning manner including a single-station warning, an area-rainfall-based warning and a multi-station warning, and step 4 of collecting rainfall data of each rainfall station in the area where the protection object is located in real time, and when a rainfall observed by a certain rainfall station exceeds a warning threshold, first determining a type to which the rainfall station belongs, and then selecting a corresponding warning manner to give a warning.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of mountain flood disaster warning technology, and particularly to a mountain flood disaster warning method based on a method of associating protection objects with rainfall observation stations. [Background technology]

[0002] Mountain flood disasters refer to the sudden increase in floods caused by heavy rainfall in mountainous areas and the secondary disasters that result from them. They are characterized by their sudden occurrence, wide-ranging impact, and high destructive power, causing great losses and threats to the safety of people's lives and property. Therefore, effective monitoring and warning of mountain flood disasters are an important issue for disaster prevention and mitigation.

[0003] In the mountain flood disaster monitoring and warning system, it is necessary to establish an association between the object to be protected from mountain flood disasters (e.g., a village) and a rain gauge station. When the rainfall observed at a certain rain gauge station exceeds the warning threshold, the mountain flood disaster monitoring and warning system will automatically issue an alert to the village associated with the rain gauge station, urging relevant parties to take disaster prevention measures in a timely manner, and avoid or mitigate the impact of mountain flood disasters.

[0004] Currently, the commonly used correlation and warning method involves linking a protected object to all rain gauge stations within its vicinity. When the rainfall observed at one of these stations exceeds the rainfall warning threshold, the mountain flood disaster monitoring and warning system issues a warning to the protected object. This correlation and warning method has two main problems: (1) When heavy rainfall occurs upstream in a river basin but the rainfall near the protected object downstream does not exceed the rainfall warning threshold, the flood may still cause a mountain flood disaster in the protected area when it reaches the village. The existing warning method does not take this situation into account and is prone to miss mountain flood disaster warnings. (2) When the density of observation stations is low and there is no rain gauge station within the vicinity of a protected object that can be associated with it, it is prone to miss mountain flood disaster warnings for that protected object. Some current research has attempted to improve the commonly used method by linking additional rain gauge stations upstream of the protected object in addition to nearby observation stations, but this has not simultaneously improved the warning method. Problems with existing improvement methods include the fact that localized, short-term heavy rainfall upstream is unlikely to cause mountain flood disasters downstream that require protection, and that issuing an alert based solely on the rainfall observed at a single observation station exceeding the alert threshold can easily result in false alerts for mountain flood disasters. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] (None in particular) Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a mountain flood disaster warning method based on a method for associating protection objects with rain gauge stations, in order to reduce the false alarm rate and missed alarm rate of mountain flood disaster warning. To achieve the above objectives, the present invention provides the following technical solutions: [Means for solving the problem]

[0007] The present invention discloses a mountain flood disaster warning method based on the association method between protection objects and rainfall observation stations, the method comprising: a step 1 of classifying rain gauge stations, where all rain gauge stations that normally provide flood warnings within an area where a protected object is located are classified based on their relative location to the protected object; Step 2: establishing a linkage scheme between the protected object and the rain gauge station, the linkage scheme between the protected object and the rain gauge station being established by calculating the density of the rain gauge station in the upstream basin of the protected object and based on the density of the rain gauge station; Step 3: constructing a mountain flood disaster warning system including single-station warning, area-based rainfall warning, and multi-station warning; and step 4, a step of determining an alert method based on the type of rain gauge station, in which rainfall data from each rain gauge station in the area where the protected object is located is collected in real time, and when the rainfall observed at a certain rain gauge station exceeds the alert threshold, the type to which the rain gauge station belongs is first determined, and then a corresponding alert method is selected to issue an alert.

[0008] Furthermore, the specific classification method for classifying all rain gauge stations that normally issue flood warnings within the area where the protection object described in step 1 is located based on their relative locations with respect to the protection object is as follows: All rainfall observation stations that normally provide flood warnings are divided into four types according to their relative locations to the protected areas, namely, Type 1 observation stations, Type 2 observation stations, Type 3 observation stations, and Type 4 observation stations. Type 1 stations are rain gauge stations within a radius of x km around the protected area, where x is determined based on the density of rain gauge stations in the area, which is the area divided by the number of stations in the area; A Type 2 observation station is a rainfall observation station that is located outside the x km radius of the protection target and within the upstream basin, with the protection target being the outlet of the basin. Type 3 stations are rainfall stations located within an x ​​km buffer zone outside the protected upstream basin. Type 4 observatories are any other observatory other than the above three types of observatories.

[0009] Furthermore, the area where the protection object is located includes the upstream watershed of the protection object and a 5 km buffer zone range, and the range of possible values ​​of x is 3 to 5.

[0010] Furthermore, the step of establishing a correlation scheme between the protection object and the rain gauge station based on the density of the rain gauge station described in step 2 specifically includes: The density of rain gauge stations in the upstream basin to be protected is the rain gauge station density threshold y km 2 If the density of rainfall stations in the upstream basin of the protected area is less than the threshold value ykm, i.e., if the distribution of rainfall stations is dense, the protected area is associated with Type 1 and Type 2 stations. 2 / If the distribution of rainfall stations is larger than the observation station, i.e., if the distribution of rainfall stations is sparse, the protection target is associated with Type 1 observation stations, Type 2 observation stations and Type 3 observation stations, and Type 4 observation stations are not associated with villages.

[0011] Furthermore, the density threshold ykm of the rain gauge station 2 The values ​​of the stations are influenced by the overall factors of the basin climate, rainfall characteristics, and the average density of stations across the province, and range from 5 to 50 km 2 / It is an observatory.

[0012] Furthermore, the single-station warning in step 3 refers to the mountain flood disaster warning system issuing a warning to a protection object when rainfall exceeding the warning threshold is observed at only one of multiple rain gauge stations associated with the protection object. The areal rainfall-based warning refers to the mountain flood disaster warning system calculating the areal rainfall in an upstream basin using rainfall observed at multiple rain gauge stations associated with the protection object, and issuing a warning to the protection object when the areal rainfall is greater than or equal to the warning threshold * α, where α is a damping coefficient α∈(0, 1). The multi-station warning refers to the mountain flood disaster warning system issuing a warning to the protection object when the areal rainfall-based warning is not triggered, i.e., when the areal rainfall < the warning threshold * α, and the rainfall observed at more than half of the rain gauge stations associated with the protection object is greater than or equal to the warning threshold, and vice versa.

[0013] Furthermore, the specific process of first determining the type of the rain gauge station in step 4 and then selecting the corresponding warning method to issue a warning is as follows: if the rain gauge station is a Type 1 station to be protected, the single-station warning method is used to issue a warning; if the rain gauge station is a Type 2 or Type 3 station to be protected, the warning method is further determined based on the upstream catchment area of ​​the protected station, and the catchment area < the catchment area threshold A km 2 If so, use the direct single-station warning method to issue a warning, and the catchment area is greater than or equal to the catchment area threshold Akm 2 If yes, the area rainfall of the basin is calculated, and if the area rainfall is greater than or equal to the warning threshold * α, the mountain flood disaster warning system issues a warning to the protected object; conversely, if the area rainfall is less than the warning threshold * α, it is determined whether the rainfall at more than half of the observation stations is greater than the warning threshold; if yes, the mountain flood disaster warning system issues a warning to the protected object; if no, the mountain flood disaster warning system does not issue a warning to the protected object.

[0014] Furthermore, the range of values ​​that the watershed area threshold A can take is 50-100. [Effects of the Invention]

[0015] The beneficial effects of the present invention are as follows: The method described in the present invention solves the problem of existing mountain flood disaster warning methods that they are unable to take into account the uneven spatial distribution of disaster-causing heavy rainfall, and can simultaneously deal with multiple situations, such as when the center of rainfall is in an upstream basin or in an area that requires protection, thereby reducing the false alarm rate and missed alarm rate of mountain flood disaster warnings and improving the accuracy of mountain flood disaster warnings.

[0016] The present invention will now be described in more detail with reference to the drawings and specific embodiments. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a flow diagram of the method according to the present invention. [Figure 2] Schematic diagram of the rain gauge station classification process. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention discloses a mountain flood disaster warning method based on the association between protection objects and rainfall observation stations, and as shown in FIG. 1, the method includes steps 1 to 4.

[0019] In step 1, the rainfall observation stations are classified, and all rainfall observation stations that normally issue flood warnings for a protection object (e.g., a village) within the area where the protection object is located (including the upstream basin of the protection object and the 5km buffer zone range) are classified into four types: Type 1 observation station, Type 2 observation station, Type 3 observation station, and Type 4 observation station, according to their relative positions to the protection object, as shown in Figure 2. The specific classification method is as follows:

[0020] A Type 1 observation station is a rain gauge station within a radius of x km, with the protected area as the center. This type of observation station can warn of mountain flood disasters caused by localized heavy rainfall in the protected area. Here, x is determined based on the density of rain gauge stations in the area (the density of rain gauge stations is the area divided by the number of stations in the area), and is generally between 3 and 5.

[0021] A Type 2 observation station is a rainfall observation station located outside the x km radius of the protected area, but within the upstream basin, with the protected area being the outlet of the basin. This type of observation station can warn of mountain flood disasters caused by a sudden increase in flow in the protected area downstream due to heavy rain upstream.

[0022] Type 3 stations are rainfall stations located within an x ​​km buffer zone outside the upstream basin of the protected area. This type of station can compensate for the sparse distribution of rainfall stations in the area where the protected area is located.

[0023] Type 4 observatories are any other observatory other than the above three types of observatories.

[0024] Step 2 is a step of establishing an association method between the protected object and the rain gauge station, in which the density of the rain gauge station in the upstream basin of the protected object is calculated, and an association method between the protected object and the rain gauge station is established based on the density of the rain gauge station, specifically as follows:

[0025] The density of rain gauge stations in the upstream basin to be protected is the rain gauge station density threshold y km 2 If the density of rainfall stations in the upstream basin of the protected area is less than the density threshold ykm, i.e., if the distribution of rainfall stations is dense, the protected area is associated with Type 1 and Type 2 stations, and the density of rainfall stations in the upstream basin of the protected area is less than the density threshold ykm. 2 / If the distribution of rainfall stations is larger than the observation station, i.e., if the distribution of rainfall stations is sparse, the protection target is associated with Type 1 observation stations, Type 2 observation stations and Type 3 observation stations, and Type 4 observation stations are not associated with villages.

[0026] where the density threshold of the rain gauge station is ykm 2 The values ​​of the observation stations are generally affected by factors such as the basin climate, rainfall characteristics, and the average density of observation stations across the province, and are generally between 5 and 50 km 2 / observation station, and smaller values ​​can be used for areas where the spatial distribution of rainfall is large or the average density of observation stations across the province is relatively high, and larger values ​​can be used for areas where the spatial distribution of rainfall is small or the average density of observation stations across the province is relatively low.

[0027] In step 3, a mountain flood disaster warning system is established, including single-station warnings, areal rainfall-based warnings, and multi-station warnings. A single-station warning refers to the mountain flood disaster warning system issuing a warning to a protected object when rainfall exceeding the warning threshold is observed at only one of the multiple rainfall stations associated with the protected object. A areal rainfall-based warning refers to the mountain flood disaster warning system calculating the areal rainfall in the upstream basin using rainfall observed at multiple rainfall stations associated with the protected object, and issuing a warning to the protected object when the areal rainfall is greater than or equal to the warning threshold * α, where α is a damping coefficient (α∈(0, 1)). It can be smaller in areas with large variations in the spatial distribution of rainfall, and larger in areas with small variations in the spatial distribution of rainfall. An alert from multiple observation stations refers to the case where an alert based on area rainfall is not triggered, i.e., when area rainfall < alarm threshold * α, if the rainfall observed at more than half of the rainfall observation stations associated with the protected object is equal to or greater than the alarm threshold, the mountain flood disaster warning system will issue an alert to the protected object and notify the related protected object to take disaster prevention measures in a timely manner; if the opposite is true, the mountain flood disaster warning system will not issue an alert to the protected object.

[0028] Step 4 is a step of determining the warning method based on the type of rain gauge station. Rainfall data from each rain gauge station in the area where the protection object is located is collected in real time. When the rainfall observed at a certain rain gauge station exceeds the warning threshold, it is first necessary to determine the type to which the station belongs. If the rain gauge station is a Type 1 protection object, a warning method based on a single observation station is used. If the rain gauge station is a Type 2 or Type 3 protection object, a warning method must be further determined based on the upstream catchment area of ​​the protection object. If the catchment area is small ( <Akm 2 ), the warning method using a single observation station is used directly, and the catchment area is large (≧ Akm 2 ) calculate the area rainfall of the basin, and if the area rainfall is greater than or equal to the warning threshold * α, the mountain flood disaster warning system will issue a warning to the protected object; conversely, if the area rainfall is less than the warning threshold * α, determine whether the rainfall at more than half of the observation stations is greater than the warning threshold. If the answer is yes, the mountain flood disaster warning system will issue a warning to the protected object; if the answer is no, the mountain flood disaster warning system will not issue a warning to the protected object. Here, A is the basin area threshold, which ranges from 50 to 100 and can take larger values ​​in areas with a steep basin gradient and smaller values ​​in areas with a shallow basin gradient.

[0029] Finally, it should be mentioned that the above description is only for explaining the technical solutions of the present invention, and is not intended to be limiting. Although the present invention has been described in detail with reference to the best arrangement means, those skilled in the art can make modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A mountain flood disaster warning method based on a method of associating a protection object with a rainfall observation station, comprising: (Step 1) A step 1 of classifying rain gauge stations, in which all rain gauge stations that normally provide flood warnings within an area in which a protected object is located are classified based on their relative location to the protected object; (Step 2) Step 2: establishing a linkage scheme between the protected object and the rain gauge station, the linkage scheme between the protected object and the rain gauge station being established by calculating the density of the rain gauge station in the upstream basin of the protected object and based on the density of the rain gauge station; (Step 3) Step 3: constructing a mountain flood disaster warning system, including single-station warning, areal rainfall-based warning, and multi-station warning; (Step 4) and step 4, a step of determining an alert method based on the type of rain gauge station, comprising: collecting rainfall data from each rain gauge station in the area where the protection object is located in real time; when the rainfall observed at a certain rain gauge station exceeds an alert threshold, first determining the type to which the rain gauge station belongs, and then selecting a corresponding alert method to issue an alert. A mountain flood disaster warning method based on a method of associating protection targets with rainfall observation stations.

2. classifying all rain gauge stations that normally provide flood warnings within the area where the object of protection according to step 1 is located based on their relative location to the object of protection; The specific classification method is as follows: All rain gauge stations that normally provide flood warnings are divided into four types according to their relative locations to the protected areas, namely, Type 1 stations, Type 2 stations, Type 3 stations, and Type 4 stations. Type 1 stations are rain gauge stations within a radius of x km, with the protected object as the center, where x is determined based on the density of rain gauge stations in the area, which is the area of ​​the area divided by the number of stations in the area; A Type 2 observation station is a rainfall observation station that extracts an upstream basin with the protection target as the basin outlet, and is located outside the x km radius range from the protection target, but within the upstream basin range. Type 3 stations are rainfall observation stations located within an x ​​km buffer zone outside the upstream catchment area to be protected. Type 4 observatories are other observatories other than the above three types of observatories. The method for warning mountain flood disasters based on the association method between protection objects and rainfall observation stations according to claim 1.

3. The area where the protection object is located includes the upstream watershed of the protection object and a 5 km buffer zone range, and the range of possible values ​​of x is 3 to 5. The method for warning mountain flood disasters based on the association method between protection objects and rainfall observation stations according to claim 2.

4. Establishing a scheme for associating the protection object with the rain gauge station based on the density of the rain gauge station as described in step 2, in particular The density of rainfall observation stations in the upstream basin of the protection target is the rainfall observation station density threshold y km ２ If the density of rainfall observation stations is less than the threshold value y km / s, i.e., if the distribution of rainfall observation stations is dense, the protection target is associated with Type 1 observation stations and Type 2 observation stations, and the density of rainfall observation stations in the upstream basin of the protection target is less than the threshold value y km / s. ２ / If the distribution of rainfall stations is larger than the number of observation stations, i.e., if the distribution of rainfall stations is sparse, the protection object is associated with Type 1 observation stations, Type 2 observation stations, and Type 3 observation stations, and Type 4 observation stations are not associated with villages; The method for warning mountain flood disasters based on the association method between protection objects and rainfall observation stations according to claim 2.

5. The density threshold y km of the rain gauge station ２ / The values ​​of the observation stations are influenced by the overall factors of the basin climate, rainfall characteristics, and the average density of observation stations across the province, and vary within 5 to 50 km. ２ / It is an observatory, The method for mountain flood disaster warning based on the association method between protection objects and rainfall observation stations according to claim 4.

6. The single-station warning in step 3 refers to the mountain flood disaster warning system issuing a warning to the protection object when rainfall exceeding the warning threshold is observed at only one of the multiple rain gauge stations associated with the protection object; the areal rainfall-based warning refers to the mountain flood disaster warning system calculating the areal rainfall of the upstream basin using rainfall observed at the multiple rain gauge stations associated with the protection object, and issuing a warning to the protection object when the areal rainfall is greater than or equal to the warning threshold * α, where α is a damping coefficient and α∈(0, 1); the multiple-station warning refers to the mountain flood disaster warning system issuing a warning to the protection object when the areal rainfall-based warning has not been triggered, i.e., when the areal rainfall is less than the warning threshold * α, and when the rainfall observed at more than half of the rain gauge stations associated with the protection object is greater than or equal to the warning threshold, and vice versa. The method for mountain flood disaster warning based on the association method between protection objects and rainfall observation stations according to claim 4.

7. The specific process of determining the type of the rain gauge station in step 4 and then selecting the corresponding warning method to issue a warning is as follows: if the rain gauge station is a Type 1 station to be protected, a single-station warning method is used to issue a warning; if the rain gauge station is a Type 2 or Type 3 station to be protected, a warning method is further determined based on the upstream catchment area of ​​the protected station, and if the catchment area is less than the catchment area threshold A km 2 If the threshold value is A km, the warning method using a single observation station is used to issue a warning. 2 If yes, calculate the area rainfall of the basin, and if the area rainfall is equal to or greater than the warning threshold * α, the mountain flood disaster warning system will issue a warning to the protection object; if the opposite is true, if the area rainfall is less than the warning threshold * α, determine whether the rainfall at more than half of the observation stations is greater than the warning threshold; if yes, the mountain flood disaster warning system will issue a warning to the protection object; if no, the mountain flood disaster warning system will not issue a warning to the protection object. The method for mountain flood disaster warning based on the association method between protection objects and rainfall observation stations according to claim 6.

8. The range of values ​​that the watershed area threshold A can take is 50 to 100. The method for warning mountain flood disasters based on the association method between protection objects and rainfall observation stations according to claim 7.

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