Medium and small river flood risk grade forecasting device based on area rainfall

Abstract

The invention relates to the technical field of flood forecasting, in particular to a medium and small river flood risk level forecasting device based on areal rainfall, which comprises an information acquisition module used for acquiring hourly areal rainfall in each hydrological station area in a drainage basin and processing to obtain return periods of areal rainfall of different time lengths; the statistical module is used for acquiring monitoring data of each hydrological station, calculating a flood recurrence period, and then carrying out statistical analysis on the recurrence periods of different levels of flood in the drainage basin according to a standard flood level; and the different-level flood model module is used for counting the correlation between the recurrence periods of the different-time-length surface rainfall and the recurrence periods of the different-level flood so as to establish different-level flood models, and the forecasting precision is improved through the models.

Description

Technical Field

[0001] The invention relates to the technical field of flood forecasting, and in particular to a device for forecasting flood risk levels of small and medium-sized rivers based on surface rainfall. Background Art

[0002] Flood forecasting is an applied science and technology that reveals and predicts the occurrence and change process of floods based on previous and current hydrological and meteorological information. It is one of the important contents of non-engineering measures for flood control, and directly serves flood prevention and rescue, rational use and protection of water resources, construction and dispatching and management of water conservancy projects, and safe production of industry and agriculture.

[0003] For example, on September 8, 2020, a patent with the publication number CN111639826A, entitled A flood warning level classification and warning method, was disclosed, including: Step 1, dividing the flood forecast level into four levels: extra-large, large, medium and small according to the recurrence period; Step 2, the corresponding warning is divided into four levels: extremely dangerous, high-risk, dangerous and low-risk for warning; it does not require burying sensors in the river basin to collect rainfall and hydrological data, and derives the annual maximum flood peak flow through historical precipitation data, and has a reliable data source; but in the above literature, the prediction is based on the collection of rainfall, and direct forecasting based on rainfall will inevitably affect the forecast accuracy. Summary of the invention

[0004] In view of this, the purpose of the present invention is to propose a device for forecasting flood risk levels of small and medium-sized rivers based on surface rainfall, so as to solve the problem affecting the forecast accuracy.

[0005] Based on the above purpose, the present invention provides a device for predicting flood risk level of small and medium-sized rivers based on surface rainfall, comprising: Information collection module: used to obtain hourly surface rainfall in each hydrological station area within the basin, and process it to obtain the recurrence period of surface rainfall of different durations; Statistics module: Obtain monitoring data from each hydrological station, calculate flood recurrence period, and then statistically analyze the recurrence period of floods of different levels in the basin according to the standard flood level; Flood model module of different levels: statistics on the correlation between the return period of surface rainfall of different durations and the return period of floods of different levels, so as to establish models of floods of different levels; Flood risk level forecasting module: obtain real-time meteorological monitoring data and the latest domestic and international numerical precipitation forecasts, and process them into actual surface rainfall and forecast surface rainfall in each hydrological station area. Calculate the surface rainfall of different durations in each forecast period based on the actual surface rainfall and forecast surface rainfall, and then forecast the flood risk level of small and medium-sized rivers in the basin based on models of floods of different levels.

[0006] Optionally, the method of obtaining the hourly surface rainfall in each hydrological station area in the watershed includes a watershed surface rainfall processing module, which is used to obtain the boundary data of each hydrological station area, select the meteorological precipitation monitoring data in the area according to the boundary data, and then calculate the hourly surface rainfall in each hydrological station area through the meteorological precipitation monitoring data.

[0007] Optionally, the hourly surface rainfall in the area of ​​each hydrological station is obtained by calculating the meteorological precipitation monitoring data using an averaging method.

[0008] Optionally, the processing to obtain the recurrence period of surface rainfall of different durations includes a recurrence period processing module for calculating the recurrence period of surface rainfall of different durations based on the hourly surface rainfall by using an extreme value statistical method.

[0009] Optionally, the extreme value statistical method includes Gumbel distribution, normal distribution or Pearson type III.

[0010] Optionally, the hydrological station area for obtaining the hourly surface rainfall is an upstream area of ​​the hydrological station.

[0011] Optionally, the surface rainfall of different durations includes 3 hours, 6 hours, 12 hours, 24 hours, 48 ​​hours, 72 hours, 96 hours and 120 hours of surface rainfall.

[0012] Optionally, the standard flood level is the hydrological flood level classified in the "Hydrological Information Forecast Specification" [GB / T22482-2008].

[0013] Optionally, the classification of hydrological flood levels includes: A flood whose flood element recurrence period is less than 5 years is a minor flood; Floods with a return period of 5 to 20 years are medium floods; Floods with a return period of 20 to 50 years are considered major floods; Floods with a recurrence period of more than 50 years are considered to be extremely large floods.

[0014] Beneficial effects of the present invention: The present invention provides a device for predicting the flood risk level of small and medium-sized rivers based on surface rainfall. The present invention can predict the flood risk level of small and medium-sized rivers in a basin by processing surface rainfall of different durations. It has good forecasting performance for the flood risk of small and medium-sized rivers caused by precipitation, and can accurately predict the meteorological risk level of small and medium-sized river floods, thereby improving the forecast accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0018] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connecting" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0019] like Figure 1 As shown, a device for predicting flood risk level of small and medium-sized rivers based on surface rainfall comprises: Information collection module: used to obtain hourly surface rainfall in each hydrological station area within the basin, and process it to obtain the recurrence period of surface rainfall of different durations; Statistics module: obtain monitoring data from each hydrological station, select the maximum water level each year, calculate the flood recurrence period, and then statistically analyze the recurrence period of floods of different levels in the basin based on the standard flood level; Flood model module of different levels: statistics on the correlation between the return period of surface rainfall of different durations and the return period of floods of different levels, so as to establish models of floods of different levels; Flood risk level forecasting module: obtain real-time meteorological monitoring data and the latest domestic and international numerical precipitation forecasts, and process them into actual surface rainfall and forecast surface rainfall in each hydrological station area. Calculate the surface rainfall of different durations in each forecast period based on the actual surface rainfall and forecast surface rainfall, and then forecast the flood risk level of small and medium-sized rivers in the basin based on models of floods of different levels.

[0020] The present invention can predict the flood risk level of small and medium-sized rivers in a basin, has good forecasting performance for the flood risk of small and medium-sized rivers caused by precipitation, can accurately forecast the meteorological risk level of small and medium-sized river floods, and improves the timeliness, stability and accuracy of the forecast by processing surface rainfall of different durations.

[0021] like Figure 1 As shown, a device for predicting flood risk level of small and medium-sized rivers based on surface rainfall comprises: Information collection module: Obtain the boundary data of the upstream area of ​​each hydrological station, select the meteorological precipitation monitoring data in the area from the meteorological big data cloud platform Tianqing according to the boundary data, and use the average method to calculate the meteorological precipitation monitoring data in the upstream area of ​​each hydrological station, so as to obtain the hourly surface rainfall in the upstream area of ​​each hydrological station, generate the upstream basin surface rainfall of each hydrological station with different durations of 3, 6, 12, 24, 48, 72, 96 and 120 hours, select the maximum value of the surface rainfall of different durations each year, and then use the extreme value statistical method to calculate the recurrence period of the surface rainfall of 3 hours, 6 hours, 12 hours, 24 hours, 48 ​​hours, 72 hours, 96 hours and 120 hours respectively, so as to obtain the recurrence period of the surface rainfall of different durations; Statistics module: Obtain the water level data and flow data of each hydrological station from the hydrological system, select the maximum water level each year, calculate the flood recurrence period, and statistically analyze the recurrence period of floods of different levels in the basin according to the hydrological flood levels divided by the "Hydrological Information Forecast Specification" [GB / T22482-2008]; Wherein, the extreme value statistical method includes Gumbel distribution, normal distribution or Pearson III type, etc.; The classification of hydrological flood levels includes: A flood whose flood element recurrence period is less than 5 years is a minor flood; Floods with a return period of 5 to 20 years are medium floods; Floods with a return period of 20 to 50 years are considered major floods; Floods with a return period of flood elements greater than 50 years are considered major floods; Flood model module of different levels: statistics on the correlation between the return period of surface rainfall of different durations and the return period of floods of different levels, so as to establish models of floods of different levels; Among them, models for floods of different levels can be tested and adjusted using historical data; Flood risk level forecasting module: Real-time meteorological monitoring data is obtained from the meteorological big data cloud platform TianQing in real time, and the actual surface rainfall in the upstream area of ​​each hydrological station is generated. The latest domestic and international numerical forecast precipitation forecasts are obtained to generate the forecast surface rainfall in the upstream area of ​​each hydrological station. The actual surface rainfall and forecast surface rainfall obtained form a sequence, and the surface rainfall of 3, 6, 12, 24, 48, 72, 96, and 120 hours is calculated respectively. It is brought into the model of different levels of floods at each hydrological station. When the model outputs that there may be a flood risk, the highest level of flood risk level and the corresponding duration and surface rainfall are output, and the flood risk level of small and medium-sized rivers in the basin is predicted.

[0022] Among them, domestic and foreign numerical precipitation forecast products include CMA, ECMWF, GFS, etc.

[0023] The present invention establishes models of floods of different grades based on the correlation between the recurrence periods of surface rainfall of different durations and the recurrence periods of floods of different grades. It has good forecasting performance for the flood risks of small and medium-sized rivers caused by precipitation, and can accurately forecast the meteorological risk levels of small and medium-sized river floods.

[0024] The device for predicting flood risk levels of small and medium-sized rivers based on surface rainfall has a good predictive effect on flood level risks of various hydrological stations in the Qiupu River basin in Chizhou City, Anhui Province.

[0025] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0026] The embodiments of the present invention are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for predicting flood risk levels of small and medium-sized rivers based on surface rainfall, characterized in that: include, Information collection module: used to obtain hourly surface rainfall in each hydrological station area within the basin, and process it to obtain the recurrence period of surface rainfall of different durations; Statistics module: Obtain monitoring data from each hydrological station, calculate flood recurrence period, and then statistically analyze the recurrence period of floods of different levels in the basin according to the standard flood level; Flood model module of different levels: statistics on the correlation between the return period of surface rainfall of different durations and the return period of floods of different levels, so as to establish models of floods of different levels; Flood risk level forecasting module: obtain real-time meteorological monitoring data and the latest domestic and international numerical precipitation forecasts, and process them into actual surface rainfall and forecast surface rainfall in each hydrological station area, calculate the surface rainfall of different durations in each forecast period based on the actual surface rainfall and forecast surface rainfall, and then predict the flood risk level of small and medium-sized rivers in the basin based on models of floods of different levels.

2. The device for predicting flood risk level of small and medium-sized rivers based on surface rainfall according to claim 1 is characterized in that: The method for obtaining the hourly surface rainfall in each hydrological station area in the basin includes a basin surface rainfall processing module, which is used to obtain the boundary data of each hydrological station area, select the meteorological precipitation monitoring data in the area according to the boundary data, and then calculate the hourly surface rainfall in each hydrological station area through the meteorological precipitation monitoring data.

3. The device for predicting flood risk level of small and medium-sized rivers based on surface rainfall according to claim 2 is characterized in that: The hourly surface rainfall in the area of ​​each hydrological station is obtained by calculating the meteorological precipitation monitoring data using the averaging method.

4. The device for predicting flood risk level of small and medium-sized rivers based on surface rainfall according to claim 1 is characterized in that: The processing obtains the recurrence period of surface rainfall of different durations, and includes a recurrence period processing module for calculating the recurrence period of surface rainfall of different durations based on the hourly surface rainfall by using an extreme value statistical method.

5. The device for predicting flood risk level of small and medium rivers based on surface rainfall according to claim 4 is characterized in that: The extreme value statistical methods include Gumbel distribution, normal distribution or Pearson type III.

6. The device for predicting flood risk level of small and medium-sized rivers based on surface rainfall according to claim 1 is characterized in that: The hydrological station area where the hourly surface rainfall is obtained is the upstream area of ​​the hydrological station.

7. The device for predicting flood risk level of small and medium-sized rivers based on surface rainfall according to claim 1 is characterized in that: The different durations of surface rainfall include 3 hours, 6 hours, 12 hours, 24 hours, 48 ​​hours, 72 hours, 96 hours and 120 hours of surface rainfall.

8. The device for predicting flood risk level of small and medium rivers based on surface rainfall according to claim 1 is characterized in that: The standard flood level is the hydrological flood level classified in the "Hydrological Information Forecast Specification" [GB / T22482-2008].

9. The device for predicting flood risk level of small and medium-sized rivers based on surface rainfall according to claim 8, characterized in that: The hydrological flood levels include: A flood whose flood element recurrence period is less than 5 years is a minor flood; Floods with a return period of 5 to 20 years are medium floods; Floods with a return period of 20 to 50 years are considered major floods; A flood whose recurrence period is greater than 50 years is considered a major flood.

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