Drought and flood sudden change event identification method, device and equipment and readable storage medium

Abstract

The invention discloses a drought and flood sudden change event identification method, device and equipment and a readable storage medium. The method comprises the following steps: acquiring a hydro meteorological sequence and an underground water resource variation corresponding to a continuous period of a region; for each period, calculating available water flux and atmospheric evaporation demand corresponding to the period based on the hydro meteorological sequence of the period and the groundwater resource variation; based on the available water flux of the period and the atmospheric evaporation demand quantity, calculating a water-heat flux residual error ratio of the period; when the probability of the data points is less than N%, determining that drought occurs in the region in the corresponding period; when the probability of the data points is greater than M%, determining that waterlogging occurs in the region in the corresponding period; and judging whether the period interval of drought and waterlogging in the region is smaller than a period threshold value, and if so, determining that the drought and flood sudden turning event occurs in the region. Therefore, the accuracy of identifying the drought and flood sudden turning event can be improved by calculating the water-heat flux residual error ratio reflecting the land-gas water-heat interaction degree in different periods.

Description

Technical Field

[0001] The present application relates to the application field of hydrology and water resources, and more specifically, to a method, device, equipment and readable storage medium for identifying drought-flood rapid transition events. Background Art

[0002] Drought-flood sudden change event refers to a compound disaster in which drought disaster and flood disaster change mutually in a basin in a short period of time, reflecting the coexistence of drought and flood disasters in a short period of time. In the context of the continuous intensification of climate, drought-flood sudden change events are increasing. The identification of drought-flood sudden change events is conducive to the formulation of relevant prevention measures, the prevention of drought-flood sudden change disasters in the basin, and the provision of data basis for ensuring the safety of basin water resources. It is of great significance in basin water resources planning.

[0003] In the existing technology, drought-flood transition events are mainly identified from the perspective of atmospheric precipitation. However, drought-flood transition events involve the water-heat interaction process between land and air. From a meteorological perspective alone, it is difficult to identify the actual drought-flood transition changes in the basin, resulting in low accuracy in the identification of drought-flood transition events in the existing technology. Summary of the invention

[0004] In view of this, the present application provides a method, device, equipment and readable storage medium for identifying drought-flood sudden transition events, which are used to solve the shortcoming of low accuracy in identifying drought-flood sudden transition events in the prior art.

[0005] In order to achieve the above objectives, the proposed solution is as follows:

[0006] A method for identifying drought-flood sudden transition events, comprising:

[0007] Obtain the hydrological and meteorological sequences and groundwater resource changes corresponding to the continuous periods in the target area;

[0008] For each period, based on the hydrological and meteorological sequence and groundwater resource changes of the period, the available water flux and atmospheric evaporation demand corresponding to the period are calculated; based on the available water flux and atmospheric evaporation demand of the period, the water-heat flux residual ratio of the period is calculated;

[0009] Based on the residual ratios of each water-heat flux, a normal distribution curve is constructed;

[0010] determining a matching data point of each water heat flux residual ratio on the normal distribution curve;

[0011] When the probability of the corresponding data point in any period is less than N%, it is determined that the target area has suffered a drought in the corresponding period; when the probability of the corresponding data point in any period is greater than M%, it is determined that the target area has suffered a waterlogging in the corresponding period, where N is less than M;

[0012] It is determined whether the period interval between the occurrence of drought and flood in the target area is less than the period threshold. If so, it is determined that a drought-flood sudden transition event occurs in the target area; if not, it is determined that no drought-flood sudden transition event occurs in the target area.

[0013] Optionally, each hydro-meteorological series includes precipitation data for the corresponding period and actual regional evapotranspiration;

[0014] Based on the hydrological and meteorological sequence of the period and the change in groundwater resources, the available water flux corresponding to the period is calculated, including:

[0015] Based on the preset water flux expression, the change of groundwater resources in the period, the precipitation data in the hydrometeorological sequence and the actual evapotranspiration of the region, the available water flux of the period is calculated;

[0016] The water flux expression is as follows:

[0017] WA i =P i -ET i +ΔTWSC i

[0018] In the formula, WA i is the available water flux in the ith cycle; P i is the precipitation data of the ith period; ET i is the actual regional evapotranspiration in the i-th cycle; ΔTWSC i is the change of groundwater resources in the ith period.

[0019] Optionally, based on the hydrological and meteorological sequence and groundwater resource changes of the period, calculating the atmospheric evaporation demand corresponding to the period includes:

[0020] Based on the hydrological and meteorological sequence of the period, the saturated water vapor pressure, the actual water vapor pressure, the soil heat flux, the average temperature at the target height and the slope of the saturated water vapor pressure curve corresponding to the period are calculated;

[0021] Based on the preset evaporation demand expression, the atmospheric evaporation demand of the period is calculated by comprehensively considering the saturated water vapor pressure, actual water vapor pressure, soil heat flux, average temperature at the target height, slope of the saturated water vapor pressure curve, net surface radiation in the hydro-meteorological sequence, and wind speed at the target height;

[0022] The evaporation demand expression is as follows:

[0023]

[0024] In the formula, ED i is the atmospheric evaporation demand corresponding to the i-th period; Ki is the slope of the saturated water vapor pressure curve corresponding to the i-th cycle; r is the hygrometer constant; U i is the target high wind speed corresponding to the ith period; Rn i is the surface net radiation corresponding to the ith period; G i is the soil heat flux corresponding to the ith period; T i is the average temperature of the target height corresponding to the i-th cycle; es i is the saturated water vapor pressure corresponding to the i-th cycle; ea i is the actual water vapor pressure corresponding to the ith period.

[0025] Optionally, each hydrological and meteorological sequence also includes an atmospheric temperature sequence, a target high altitude temperature sequence and a dew point temperature of a corresponding period;

[0026] Based on the hydrological and meteorological sequence of the period, the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high average temperature and the slope of the saturated water vapor pressure curve corresponding to the period are calculated, including:

[0027] Calculate the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high temperature average and the slope of the saturated water vapor pressure curve corresponding to the period based on the atmospheric temperature sequence, target high temperature sequence and dew point temperature of the period using a preset functional relationship group;

[0028] The functional relationship group is as follows:

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035] In the formula, Δt i is the time step of the ith cycle; Cs is the soil heat capacity; T iy is the atmospheric temperature at the end of the ith period; T iy-1 is the atmospheric temperature at the beginning of the ith period; T imax is the target maximum temperature at high altitude in the i-th cycle; T imin is the target high minimum temperature of the i-th cycle; e0 i is the air temperature of the ith cycle; T idew is the dew point temperature of the ith cycle.

[0036] Optionally, each hydrometeorological series includes the actual regional evapotranspiration for the corresponding period;

[0037] Based on the available water flux of the period and the atmospheric evaporation demand, the water heat flux residual ratio of the period is calculated, including:

[0038] Calculating the water-heat flux residual ratio of the period using a preset residual ratio expression, the actual regional evapotranspiration of the period, the available water flux and the atmospheric evaporation demand;

[0039] The residual ratio expression is as follows:

[0040]

[0041] In the formula, WER i is the residual ratio of water heat flux in the ith cycle; WA i is the available water flux in the ith cycle; ED i is the atmospheric evaporation demand corresponding to the i-th period; ET i is the actual regional evapotranspiration in the ith period.

[0042] Optionally, constructing a normal distribution curve based on each water heat flux residual ratio includes:

[0043] Each water-heat flux residual ratio is detrended, and the z-score method is used to process each detrended water-heat flux residual ratio to form a normal residual ratio that obeys a standardized normal distribution;

[0044] Based on each normal residual ratio, a normal distribution curve is plotted.

[0045] Optionally, detrending each water heat flux residual ratio, and processing each detrended water heat flux residual ratio using a z-score method to form a normal residual ratio that obeys a standardized normal distribution, includes:

[0046] Calculate the mean and standard deviation of each detrended water-heat flux residual ratio;

[0047] Substitute the mean, standard deviation, and each detrended water and heat flux residual ratio into the preset z-score expression to calculate the normal residual ratio corresponding to each period;

[0048] The z-score expression is as follows:

[0049]

[0050] In the formula, SWER iis the normal residual ratio corresponding to the i-th period; WER′ i is the detrended water heat flux residual ratio corresponding to the ith period; μ is the mean of each detrended water heat flux residual ratio; σ is the standard deviation of each detrended water heat flux residual ratio.

[0051] A drought-flood rapid transition event recognition device, comprising:

[0052] An acquisition module is used to obtain the hydrological and meteorological sequences and groundwater resource changes corresponding to the continuous periods of the target area;

[0053] A calculation module is used to calculate the available water flux and atmospheric evaporation demand corresponding to each period based on the hydrological and meteorological sequence and groundwater resource changes of the period; and calculate the water-heat flux residual ratio of the period based on the available water flux and atmospheric evaporation demand of the period;

[0054] A construction module for constructing a normal distribution curve based on the ratio of each water heat flux residual;

[0055] A determination module, used for determining a data point matching each water heat flux residual ratio on the normal distribution curve;

[0056] A comparison module, for determining that a drought disaster occurs in the target area in the corresponding period when the probability of the corresponding data point in any period is less than N%; for determining that a waterlogging disaster occurs in the target area in the corresponding period when the probability of the corresponding data point in any period is greater than M%, wherein N is less than M;

[0057] The judgment module is used to judge whether the period interval between drought and flood in the target area is less than the period threshold. If so, it is determined that a drought-flood sudden transition event occurs in the target area; if not, it is determined that no drought-flood sudden transition event occurs in the target area.

[0058] A drought-flood rapid transition event recognition device, comprising a memory and a processor;

[0059] The memory is used to store programs;

[0060] The processor is used to execute the program to implement each step of the above-mentioned drought-flood rapid transition event identification method.

[0061] A readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, each step of the above-mentioned drought-flood rapid transition event identification method is implemented.

[0062] It can be seen from the above technical solutions that the drought-flood sudden change event identification method provided by the present application can obtain the hydrological and meteorological sequences and groundwater resource changes corresponding to the continuous cycles of the target area; for each cycle, based on the hydrological and meteorological sequences and groundwater resource changes of the cycle, the available water flux and atmospheric evaporation demand corresponding to the cycle are calculated; based on the available water flux and atmospheric evaporation demand of the cycle, the water-heat flux residual ratio of the cycle is calculated; on this basis, since the available water flux can usually be defined as the total available surface water resources and the change in groundwater resource reserves The sum of the available water flux and the atmospheric evaporation demand, therefore, the calculated available water flux reflects the surface water information and groundwater information; since the atmospheric evaporation demand corresponds to the atmospheric demand for water, that is, the drying or evaporation capacity, the calculated atmospheric evaporation demand can reflect the water-heat interaction process; based on this, the water-heat flux residual ratio calculated using the available water flux and the atmospheric evaporation demand reflects the degree of water-heat interaction between the land and the atmosphere, not only considering the atmospheric precipitation information, but also integrating the land water information and the water-heat interaction information between the atmosphere and the land, further improving the reliability of the water-heat flux residual ratio; based on each water-heat flux The residual ratio of water and heat flux is used to construct a normal distribution curve; the data points matching each water and heat flux residual ratio are determined on the normal distribution curve; when the probability of the corresponding data point in any period is less than N%, it is determined that the target area will suffer from drought in the corresponding period; when the probability of the corresponding data point in any period is greater than M%, it is determined that the target area will suffer from waterlogging in the corresponding period, where N is less than M; based on this, the probability corresponding to the water and heat flux residual ratio of each period can be compared with the preset threshold to evaluate the degree of water-heat interaction in each period, and further evaluate whether the target area will suffer from waterlogging in each period. drought or waterlogging occurs; subsequently, it can be determined whether the period interval between the occurrence of drought and waterlogging in the target area is less than the period threshold; if so, it is determined that a drought-waterlogging sudden transition event occurs in the target area; if not, it is determined that no drought-waterlogging sudden transition event occurs in the target area; based on this, it can be determined whether a drought-waterlogging sudden transition event occurs in the target area within a short period of time; it can be seen that the present application can complete drought and waterlogging identification by calculating the water-heat flux residual ratio reflecting the degree of land-air water-heat interaction in different periods, and determine whether a drought-waterlogging sudden transition disaster occurs by judging whether drought and waterlogging occur within a short period of time.

[0063] In the process of calculating the water-heat flux residual ratio, the present application integrates surface water information, groundwater information and atmospheric evaporation demand reflecting the land-air water-heat interaction process, further ensuring that the water-heat flux residual ratio can reflect the degree of land-air water-heat interaction, thereby improving the recognition reliability of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the embodiments of the present application 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 application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0065] Figure 1 A flow chart of a method for identifying drought-flood sudden change events disclosed in an embodiment of the present application;

[0066] Figure 2 This is a structural block diagram of a drought-flood rapid transition event identification device disclosed in an embodiment of the present application;

[0067] Figure 3 This is a hardware structure block diagram of a drought-flood sudden change event identification device disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0069] The drought-flood transition event identification method of the present application can be used in many general or special computing device environments or configurations, such as personal computers, server computers, handheld devices or portable devices, tablet devices, multi-processor devices, and distributed computing environments including any of the above devices or equipment.

[0070] Next, combine Figure 1 The drought-flood sudden change event identification method of the present application is introduced in detail, including the following steps:

[0071] Step S1, obtaining the hydrological and meteorological sequence and groundwater resource changes corresponding to the continuous period of the target area.

[0072] Specifically, the hydrological and meteorological data of the target area between 1982 and 2015 can be obtained, and based on the hydrological and meteorological data of the target area between 1982 and 2015, hydrological and meteorological data of multiple consecutive periods can be constructed with one month as a period.

[0073] Among them, meteorological data can be derived from the fifth-generation reanalysis global climate dataset of the European Centre for Medium-Range Weather Forecasts, the change in groundwater resources can be derived from the land water storage change dataset of the Gravity Recovery and Climate Experiment GRACE launched by NASA, and the regional actual evapotranspiration in the hydrological data can be derived from the global land evapotranspiration dataset based on the PEW model of the National Tibetan Plateau Science Data Center.

[0074] Each hydrological and meteorological series may include the target high-altitude wind speed, precipitation data, actual regional evapotranspiration, atmospheric temperature series, surface net radiation, target high-altitude temperature series and dew point temperature for the corresponding period.

[0075] Each groundwater resource change may be the difference between the groundwater resource reserves at the beginning and end of the corresponding period.

[0076] Step S2: for each cycle, based on the hydro-meteorological sequence and groundwater resource changes of the cycle, calculate the available water flux and atmospheric evaporation demand corresponding to the cycle; based on the available water flux and atmospheric evaporation demand of the cycle, calculate the water-heat flux residual ratio of the cycle.

[0077] Specifically, the available water flux and atmospheric evaporation demand for each period can be calculated based on the hydro-meteorological sequence and groundwater resource changes in each period;

[0078] The available water flux and atmospheric evaporation demand in each cycle can be numerically calculated to obtain the residual ratio of water and heat flux in each cycle.

[0079] Among them, the available water flux of the target area in the field of water resources can usually be defined as the total available water resources, that is, the maximum amount of water that can be used once in the local water resources through economically reasonable and technically feasible measures within the foreseeable period, on the basis of taking into account the water use for life, production and ecological environment. It can be obtained by adding the non-repetitive amount of surface water resources and groundwater resources and the available surface water resources. In the natural environment, it is not necessary to take into account the water use for human activities, so the available water flux can be further defined as the sum of the total available surface water resources and the change in groundwater resources reserves.

[0080] The atmospheric evaporation demand is a complex concept. It is different from the actual regional evapotranspiration, which represents the upward water flux from the soil, free water surface and / or vegetation to the atmosphere. The atmospheric evaporation demand does not correspond to the land-air flux, but to the atmospheric demand for water, that is, the drying or evaporation capacity. It is a function of the state and dynamics of the atmospheric boundary layer. It is defined as the maximum amount of water that enters the atmosphere by evaporation from the free water surface under certain meteorological conditions. It can usually be expressed by potential evaporation PET. Potential evapotranspiration cannot be measured directly and needs to be calculated based on climate parameters, surface type, surface water such as lakes and seas, soil type, vegetation cover, etc. In natural environments, the Penman-Monteith formula of FAO 56 is usually used to calculate the potential evapotranspiration of the target area.

[0081] Each water-heat flux residual ratio can be used to determine the degree of land-air water-heat interaction in the corresponding period.

[0082] Step S3: construct a normal distribution curve based on each water heat flux residual ratio.

[0083] Specifically, each water-heat flux residual ratio may be standardized, and a standardized normal distribution curve may be constructed based on each standardized water-heat flux residual ratio.

[0084] Step S4, determining a data point on the normal distribution curve where each water heat flux residual ratio matches.

[0085] Specifically, the data point corresponding to each water heat flux residual ratio can be found on the normal distribution curve.

[0086] Step S5: when the probability of corresponding data points in any period is less than N%, it is determined that drought disaster occurs in the target area in the corresponding period; when the probability of corresponding data points in any period is greater than M%, it is determined that waterlogging disaster occurs in the target area in the corresponding period.

[0087] Specifically, the residual ratio of water and heat flux corresponding to the data point with probability N% is the critical value of drought in the target area; the residual ratio of water and heat flux corresponding to the data point with probability M% is the critical value of waterlogging in the target area. N is less than M.

[0088] Wherein, N can be 10 and M can be 90.

[0089] If the water-heat flux residual ratio of any period is less than the water-heat flux residual ratio corresponding to the data point with a probability of N%, the land-air water-heat interaction degree of the corresponding period is poor, and drought is prone to occur; if the water-heat flux residual ratio of any period is greater than the water-heat flux residual ratio corresponding to the data point with a probability of M%, the land-air water-heat interaction degree of the corresponding period is high, and waterlogging is prone to occur; if the probability of the corresponding data point of any period is greater than N% and less than M%, the land-air water-heat interaction degree of the corresponding period is normal, and neither drought nor waterlogging will occur in the target area during the corresponding period.

[0090] Therefore, the probability corresponding to the data point of each period can be compared with N% and M% to determine whether drought or flood occurs in the target area in the corresponding period or it is normal.

[0091] Step S6, determining whether the period interval between drought and flood in the target area is less than a period threshold, if so, determining that a drought-flood transition event occurs in the target area; if not, determining that no drought-flood transition event occurs in the target area.

[0092] Specifically, the drought cycle corresponding to the drought and the flood cycle corresponding to the flood can be determined, the period interval between the drought cycle and the flood cycle can be calculated, and the period interval can be compared with a preset period threshold. If the period interval is less than the period threshold, there is a sudden drought-flood transition event in the target area. If it is greater than the period threshold, there is no sudden drought-flood transition event in the target area.

[0093] The period threshold may be 3.

[0094] It can be seen from the above technical solutions that the drought-flood sudden change event identification method provided by the present application can obtain the hydrological and meteorological sequences and groundwater resource changes corresponding to the continuous cycles of the target area; for each cycle, based on the hydrological and meteorological sequences and groundwater resource changes of the cycle, the available water flux and atmospheric evaporation demand corresponding to the cycle are calculated; based on the available water flux and atmospheric evaporation demand of the cycle, the water-heat flux residual ratio of the cycle is calculated; on this basis, since the available water flux can usually be defined as the total available surface water resources and the change in groundwater resource reserves The sum of the available water flux and the atmospheric evaporation demand, therefore, the calculated available water flux reflects the surface water information and groundwater information; since the atmospheric evaporation demand corresponds to the atmospheric demand for water, that is, the drying or evaporation capacity, the calculated atmospheric evaporation demand can reflect the water-heat interaction process; based on this, the water-heat flux residual ratio calculated using the available water flux and the atmospheric evaporation demand reflects the degree of water-heat interaction between the land and the atmosphere, not only considering the atmospheric precipitation information, but also integrating the land water information and the water-heat interaction information between the atmosphere and the land, further improving the reliability of the water-heat flux residual ratio; based on each water-heat flux The residual ratio of water and heat flux is used to construct a normal distribution curve; the data points matching each water and heat flux residual ratio are determined on the normal distribution curve; when the probability of the corresponding data point in any period is less than N%, it is determined that the target area will suffer from drought in the corresponding period; when the probability of the corresponding data point in any period is greater than M%, it is determined that the target area will suffer from waterlogging in the corresponding period, where N is less than M; based on this, the probability corresponding to the water and heat flux residual ratio of each period can be compared with the preset threshold to evaluate the degree of water-heat interaction in each period, and further evaluate whether the target area will suffer from waterlogging in each period. drought or waterlogging occurs; subsequently, it can be determined whether the period interval between the occurrence of drought and waterlogging in the target area is less than the period threshold; if so, it is determined that a drought-waterlogging sudden transition event occurs in the target area; if not, it is determined that no drought-waterlogging sudden transition event occurs in the target area; based on this, it can be determined whether a drought-waterlogging sudden transition event occurs in the target area within a short period of time; it can be seen that the present application can complete drought and waterlogging identification by calculating the water-heat flux residual ratio reflecting the degree of land-air water-heat interaction in different periods, and determine whether a drought-waterlogging sudden transition disaster occurs by judging whether drought and waterlogging occur within a short period of time.

[0095] In the process of calculating the water-heat flux residual ratio, the present application integrates surface water information, groundwater information and atmospheric evaporation demand reflecting the land-air water-heat interaction process, further ensuring that the water-heat flux residual ratio can reflect the degree of land-air water-heat interaction, thereby improving the recognition reliability of the present application.

[0096] In addition, accurate identification of drought-flood transition events can comprehensively and effectively monitor or predict changes in dry and wet conditions in the target area, thereby more accurately identifying drought-flood transition events, which is of great significance for the analysis and prevention of drought and flood disasters in the target area.

[0097] In some embodiments of the present application, the process of calculating the available water flux corresponding to the period based on the hydrological and meteorological sequence and groundwater resource change of the period in step S2 is described in detail, and the steps are as follows:

[0098] S20. Based on a preset water flux expression, the change in groundwater resources in the period, precipitation data in the hydrometeorological sequence, and actual regional evapotranspiration, the available water flux of the period is calculated.

[0099] Specifically, the change in groundwater resources in each cycle, the precipitation data in the hydrological and meteorological series, and the actual evapotranspiration in the region can be substituted into the water flux expression to calculate the available water flux in each cycle.

[0100] The water flux expression can be shown as follows:

[0101] WA i =P i -ET i +ΔTWSC i

[0102] In the formula, WA i is the available water flux in the ith cycle; P i is the precipitation data of the ith period; ET i is the actual regional evapotranspiration in the i-th cycle; ΔTWSC i is the change of groundwater resources in the ith period.

[0103] It can be seen from the above technical solution that this embodiment provides an optional method for calculating the available water flux. Through the above method, the available water flux can be further calculated by integrating precipitation, actual regional evapotranspiration and groundwater resource changes, so that the available water flux can reflect the actual land-air interaction process in the target area.

[0104] In some embodiments of the present application, the process of calculating the atmospheric evaporation demand corresponding to the period based on the hydrological and meteorological sequence and groundwater resource change of the period in step S2 is described in detail, and the steps are as follows:

[0105] S21. Based on the hydrological and meteorological sequence of the period, calculate the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high average temperature and the slope of the saturated water vapor pressure curve corresponding to the period.

[0106] Specifically, the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high altitude average temperature and the slope of the saturated water vapor pressure curve corresponding to each period can be calculated based on the target high altitude wind speed, atmospheric temperature sequence, target high altitude temperature sequence and dew point temperature in each period of hydrological and meteorological sequence.

[0107] S22. Based on a preset evaporation demand expression, the atmospheric evaporation demand of the period is calculated by comprehensively considering the saturated water vapor pressure, actual water vapor pressure, soil heat flux, average temperature at a target height, the slope of the saturated water vapor pressure curve, and the wind speed at a target height in the hydro-meteorological sequence.

[0108] Specifically, the saturated water vapor pressure, actual water vapor pressure, soil heat flux, average temperature at the target height, the slope of the saturated water vapor pressure curve, the surface net radiation in the hydrometeorological sequence, and the wind speed at the target height of each period can be substituted into the preset evaporation demand expression to calculate the atmospheric evaporation demand for each period.

[0109] The evaporation demand expression can be shown as follows:

[0110]

[0111] In the formula, ED i is the atmospheric evaporation demand corresponding to the i-th period; K i is the slope of the saturated water vapor pressure curve corresponding to the i-th cycle; r is the hygrometer constant; U i is the target high wind speed corresponding to the ith period; Rn i is the surface net radiation corresponding to the ith period; G i is the soil heat flux corresponding to the ith period; T i is the average temperature of the target height corresponding to the i-th cycle; es i is the saturated water vapor pressure corresponding to the i-th cycle; ea i is the actual water vapor pressure corresponding to the ith period.

[0112] The height of the target height can be set according to actual needs, for example, it can be set to 2m.

[0113] It can be seen from the above technical solution that this embodiment provides an optional method for calculating the atmospheric evaporation demand. Through the above method, the calculation of the atmospheric evaporation demand can be further integrated from multiple angles, thereby further improving the accuracy of the atmospheric evaporation demand.

[0114] In some embodiments of the present application, step S21, based on the hydrological and meteorological sequence of the period, the process of calculating the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high average temperature and the slope of the saturated water vapor pressure curve corresponding to the period is described in detail, and the steps are as follows:

[0115] S210. Using a preset functional relationship group, based on the atmospheric temperature sequence, target high temperature sequence and dew point temperature of the period, calculate the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high average temperature and the slope of the saturated water vapor pressure curve corresponding to the period.

[0116] Specifically, the atmospheric temperature sequence, target high temperature sequence and dew point temperature of each period can be substituted into the preset function relationship group to calculate the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high average temperature and the slope of the saturated water vapor pressure curve corresponding to each period.

[0117] Among them, the function relationship group can be as follows:

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124] In the formula, Δt i is the time step of the ith cycle; Cs is the soil heat capacity; T iy is the atmospheric temperature at the end of the ith period; T iy-1 is the atmospheric temperature at the beginning of the ith period; T imax is the target maximum temperature at high altitude in the i-th cycle; T imin is the target high minimum temperature of the i-th cycle; e0 i is the air temperature of the ith cycle; T idew is the dew point temperature of the ith cycle.

[0125] It can be seen from the above technical solution that this embodiment provides an optional method for calculating the saturated water vapor pressure, actual water vapor pressure, soil heat flux, average temperature at the target height and the slope of the saturated water vapor pressure curve, so as to better obtain the atmospheric evaporation demand.

[0126] In some embodiments of the present application, the process of calculating the water heat flux residual ratio of the cycle based on the available water flux of the cycle and the atmospheric evaporation demand in step S2 is described in detail, and the steps are as follows:

[0127] S223. Calculate the water-heat flux residual ratio of the period using a preset residual ratio expression, the actual regional evapotranspiration of the period, the available water flux and the atmospheric evaporation demand.

[0128] Specifically, the actual regional evapotranspiration, available water flux and atmospheric evaporation demand of each cycle can be substituted into the preset residual ratio expression to calculate the water heat flux residual ratio of each cycle.

[0129] Among them, the residual ratio expression can be shown as follows:

[0130]

[0131] In the formula, WER i is the residual ratio of water heat flux in the ith cycle; WA i is the available water flux in the ith cycle; ED i is the atmospheric evaporation demand corresponding to the i-th period; ET i is the actual regional evapotranspiration in the ith period.

[0132] It can be seen from the above technical solution that this embodiment provides an optional method for calculating the water-heat flux residual ratio. Through the above method, the actual regional evapotranspiration, available water flux and atmospheric evaporation demand can be comprehensively considered to calculate the water-heat flux residual ratio, thereby further improving the ability of the water-heat flux residual ratio to characterize the land-air water-heat interaction process and further improving the accuracy of this application.

[0133] In some embodiments of the present application, step S3, the process of constructing a normal distribution curve based on each water heat flux residual ratio is described in detail, and the steps are as follows:

[0134] S30, detrending each water-heat flux residual ratio, and processing each detrended water-heat flux residual ratio using the z-score method to form a normal residual ratio that obeys a standardized normal distribution.

[0135] Specifically, the optimal fitting method can be used to construct a trend line for fitting the curve composed of the residual ratios of each water heat flux;

[0136] Based on the trend line, the trend value of each water-heat flux residual ratio can be determined, and the corresponding trend value can be subtracted from each water-heat flux residual ratio to obtain the detrended water-heat flux residual ratio;

[0137] The residual ratio standardization expression constructed based on the z-score method can be used to process each detrended water and heat flux residual ratio to form a normal residual ratio that obeys the standardized normal distribution.

[0138] S31. Draw a normal distribution curve based on each normal residual ratio.

[0139] Specifically, the normal distribution curve is drawn by taking the mean of each normal residual ratio as the center position of the normal distribution curve and taking the standard deviation of each normal residual ratio as the shape parameter of the normal distribution curve.

[0140] It can be seen from the above technical solution that this embodiment provides an optional method for constructing a normal distribution curve based on each water-heat flux residual ratio. Through the above method, the normal distribution curve can be better utilized to determine the probability corresponding to each water-heat flux residual ratio, so as to better complete the identification of drought and flood disasters.

[0141] In some embodiments of the present application, the process of using the z-score method in step S30 to process each detrended water heat flux residual ratio to form a normal residual ratio that obeys a standardized normal distribution is described in detail, and the steps are as follows:

[0142] S300, calculating the mean and standard deviation of each detrended water heat flux residual ratio.

[0143] Specifically, the ratio between the sum of the water heat flux residual ratios after detrending and the numerical value of each water heat flux residual ratio can be used as the mean of each water heat flux residual ratio after detrending.

[0144] The standard deviation of each detrended water heat flux residual ratio can be calculated based on the mean of each detrended water heat flux residual ratio.

[0145] S301, substituting the mean, standard deviation and each detrended water and heat flux residual ratio into a preset z-score expression, and calculating the normal residual ratio corresponding to each period.

[0146] Specifically, the residual ratio normalization expression can be shown as follows:

[0147]

[0148] Where μ is the mean of the residual ratios of water heat flux; σ is the standard deviation of the residual ratios of water heat flux; SWER i is the normal residual ratio of the ith period.

[0149] It can be seen from the above technical solution that this embodiment provides an optional method for converting the water heat flux residual ratio into a normal residual ratio, and the probability of each water heat flux residual ratio can be further determined by the above method.

[0150] Next, we will combine Figure 2 The drought-flood sudden transition event identification device provided in the present application is introduced in detail. The drought-flood sudden transition event identification device provided below can be compared with the drought-flood sudden transition event identification method provided above.

[0151] See also Figure 2 It can be found that the drought-flood sudden change event identification device may include:

[0152] An acquisition module 10 is used to acquire the hydrological and meteorological sequence and groundwater resource changes corresponding to the continuous period of the target area;

[0153] The calculation module 20 is used to calculate the available water flux and atmospheric evaporation demand corresponding to each period based on the hydrological and meteorological sequence and groundwater resource changes of the period; and calculate the water-heat flux residual ratio of the period based on the available water flux and atmospheric evaporation demand of the period;

[0154] A construction module 30 is used to construct a normal distribution curve based on each water heat flux residual ratio;

[0155] A determination module 40, for determining a data point on the normal distribution curve where each water heat flux residual ratio matches;

[0156] A comparison module 50 is used to determine that a drought disaster occurs in the target area in the corresponding period when the probability of the corresponding data point in any period is less than N%; and to determine that a waterlogging disaster occurs in the target area in the corresponding period when the probability of the corresponding data point in any period is greater than M%, wherein N is less than M;

[0157] The judgment module 60 is used to judge whether the period interval between the occurrence of drought and flood in the target area is less than the period threshold. If so, it is determined that a drought-flood sudden transition event occurs in the target area; if not, it is determined that no drought-flood sudden transition event occurs in the target area.

[0158] Furthermore, the calculation module may include:

[0159] An available water flux calculation unit is used to calculate the available water flux of the period based on a preset water flux expression, the change of groundwater resources in the period, the precipitation data in the hydrometeorological sequence and the actual evapotranspiration of the region;

[0160] The water flux expression is as follows:

[0161] WA i =Pi -ET i +ΔTWSC i

[0162] In the formula, WA i is the available water flux in the ith cycle; P i is the precipitation data of the ith period; ET i is the actual regional evapotranspiration in the i-th cycle; ΔTWSC i is the change of groundwater resources in the ith period.

[0163] Furthermore, the calculation module may also include:

[0164] A soil heat flux calculation unit, for calculating the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high average temperature and the slope of the saturated water vapor pressure curve corresponding to the period based on the hydrological and meteorological sequence of the period;

[0165] An atmospheric evaporation demand calculation unit, for calculating the atmospheric evaporation demand of the period based on a preset evaporation demand expression, by integrating the saturated water vapor pressure of the period, the actual water vapor pressure, the soil heat flux, the average temperature at the target height, the slope of the saturated water vapor pressure curve, the surface net radiation in the hydrological and meteorological sequence, and the wind speed at the target height;

[0166] The evaporation demand expression is as follows:

[0167]

[0168] In the formula, ED i is the atmospheric evaporation demand corresponding to the i-th period; K i is the slope of the saturated water vapor pressure curve corresponding to the i-th cycle; r is the hygrometer constant; U i is the target high wind speed corresponding to the ith period; Rn i is the surface net radiation corresponding to the ith period; G i is the soil heat flux corresponding to the ith period; T i is the average temperature of the target height corresponding to the i-th cycle; es i is the saturated water vapor pressure corresponding to the i-th cycle; ea i is the actual water vapor pressure corresponding to the ith period.

[0169] Furthermore, the soil heat flux calculation unit may include:

[0170] A function relationship group utilizing component, for calculating the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high temperature average and the slope of the saturated water vapor pressure curve corresponding to the period based on the atmospheric temperature sequence, target high temperature sequence and dew point temperature of the period using a preset function relationship group;

[0171] The functional relationship group is as follows:

[0172]

[0173]

[0174]

[0175]

[0176]

[0177]

[0178] In the formula, Δt i is the time step of the ith cycle; Cs is the soil heat capacity; T iy is the atmospheric temperature at the end of the ith period; T iy-1 is the atmospheric temperature at the beginning of the ith period; T imax is the target maximum temperature at high altitude in the i-th cycle; T imin is the target high minimum temperature of the i-th cycle; e0 i is the air temperature of the ith cycle; T idew is the dew point temperature of the ith cycle.

[0179] Furthermore, the calculation module may also include:

[0180] A water heat flux residual ratio calculation unit, used to calculate the water heat flux residual ratio of the period using a preset residual ratio expression, the actual regional evapotranspiration of the period, the available water flux and the atmospheric evaporation demand;

[0181] The residual ratio expression is as follows:

[0182]

[0183] In the formula, WER i is the residual ratio of water heat flux in the ith cycle; WA i is the available water flux in the ith cycle; ED i is the atmospheric evaporation demand corresponding to the i-th period; ET i is the actual regional evapotranspiration in the ith period.

[0184] Further, building blocks may include:

[0185] The water-heat flux residual ratio processing unit is used to detrend each water-heat flux residual ratio, and use the z-score method to process each detrended water-heat flux residual ratio to form a normal residual ratio that obeys a standardized normal distribution;

[0186] The normal distribution curve drawing unit is used to draw a normal distribution curve based on each normal residual ratio.

[0187] Further, the water heat flux residual ratio processing unit may include:

[0188] The standard deviation calculation component is used to calculate the mean and standard deviation of each detrended water heat flux residual ratio;

[0189] The normal residual ratio calculation component is used to substitute the mean, standard deviation and each detrended water and heat flux residual ratio into the preset z-score expression to calculate the normal residual ratio corresponding to each period;

[0190] The z-score expression is as follows:

[0191]

[0192] In the formula, SWER i is the normal residual ratio corresponding to the i-th period; WER′ i is the detrended water heat flux residual ratio corresponding to the ith period; μ is the mean of each detrended water heat flux residual ratio; σ is the standard deviation of each detrended water heat flux residual ratio.

[0193] The drought-flood transition event recognition device provided in the embodiment of the present application can be applied to drought-flood transition event recognition devices, such as PC terminals, cloud platforms, servers and server clusters. Figure 3 The hardware structure diagram of the drought-flood rapid change event recognition device is shown in FIG. Figure 3 ,The hardware structure of the drought-flood rapid transition event recognition device may include: at least one processor 1, at least one communication interface 2, at least one memory 3 and at least one communication bus 4;

[0194] In the embodiment of the present application, the number of the processor 1, the communication interface 2, the memory 3, and the communication bus 4 is at least one, and the processor 1, the communication interface 2, and the memory 3 communicate with each other through the communication bus 4;

[0195] The processor 1 may be a central processing unit CPU, or an application-specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present invention, etc.;

[0196] The memory 3 may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory;

[0197] The memory stores a program, and the processor can call the program stored in the memory, wherein the program is used to:

[0198] Obtain the hydrological and meteorological sequences and groundwater resource changes corresponding to the continuous periods in the target area;

[0199] For each period, based on the hydrological and meteorological sequence and groundwater resource changes of the period, the available water flux and atmospheric evaporation demand corresponding to the period are calculated; based on the available water flux and atmospheric evaporation demand of the period, the water-heat flux residual ratio of the period is calculated;

[0200] Based on the residual ratios of each water-heat flux, a normal distribution curve is constructed;

[0201] determining a matching data point of each water heat flux residual ratio on the normal distribution curve;

[0202] When the probability of the corresponding data point in any period is less than N%, it is determined that the target area has suffered a drought in the corresponding period; when the probability of the corresponding data point in any period is greater than M%, it is determined that the target area has suffered a waterlogging in the corresponding period, where N is less than M;

[0203] It is determined whether the period interval between the occurrence of drought and flood in the target area is less than the period threshold. If so, it is determined that a drought-flood sudden transition event occurs in the target area; if not, it is determined that no drought-flood sudden transition event occurs in the target area.

[0204] Optionally, the detailed functions and extended functions of the program may refer to the above description.

[0205] The embodiment of the present application further provides a readable storage medium, which may store a program suitable for execution by a processor, wherein the program is used to:

[0206] Obtain the hydrological and meteorological sequences and groundwater resource changes corresponding to the continuous periods in the target area;

[0207] For each period, based on the hydrological and meteorological sequence and groundwater resource changes of the period, the available water flux and atmospheric evaporation demand corresponding to the period are calculated; based on the available water flux and atmospheric evaporation demand of the period, the water-heat flux residual ratio of the period is calculated;

[0208] Based on the residual ratios of each water-heat flux, a normal distribution curve is constructed;

[0209] determining a matching data point of each water heat flux residual ratio on the normal distribution curve;

[0210] When the probability of the corresponding data point in any period is less than N%, it is determined that the target area has suffered a drought in the corresponding period; when the probability of the corresponding data point in any period is greater than M%, it is determined that the target area has suffered a waterlogging in the corresponding period, where N is less than M;

[0211] It is determined whether the period interval between the occurrence of drought and flood in the target area is less than the period threshold. If so, it is determined that a drought-flood sudden transition event occurs in the target area; if not, it is determined that no drought-flood sudden transition event occurs in the target area.

[0212] Optionally, the detailed functions and extended functions of the program may refer to the above description.

[0213] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0214] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0215] The above description of the disclosed embodiments enables professionals and technicians in the field to implement or use the present application. Various modifications to these embodiments will be apparent to professionals and technicians in the field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. The various embodiments of the present application can be combined with each other. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for identifying drought-flood sudden change events, It is characterized in that include: Obtain the hydrological and meteorological sequences and groundwater resource changes corresponding to the continuous periods in the target area; For each period, based on the hydrological and meteorological sequence and groundwater resource changes of the period, the available water flux and atmospheric evaporation demand corresponding to the period are calculated; based on the available water flux and atmospheric evaporation demand of the period, the water-heat flux residual ratio of the period is calculated; Based on the residual ratios of each water-heat flux, a normal distribution curve is constructed; determining a matching data point of each water heat flux residual ratio on the normal distribution curve; When the probability of the corresponding data point in any period is less than N%, it is determined that the target area has suffered a drought in the corresponding period; when the probability of the corresponding data point in any period is greater than M%, it is determined that the target area has suffered a waterlogging in the corresponding period, where N is less than M; It is determined whether the period interval between the occurrence of drought and flood in the target area is less than the period threshold. If so, it is determined that a drought-flood sudden transition event occurs in the target area; if not, it is determined that no drought-flood sudden transition event occurs in the target area.

2. The method for identifying drought-flood transition events according to claim 1, It is characterized in that Each hydro-meteorological series includes the precipitation data of the corresponding period and the actual evapotranspiration of the region; Based on the hydrological and meteorological sequence of the period and the change in groundwater resources, the available water flux corresponding to the period is calculated, including: Based on the preset water flux expression, the change of groundwater resources in the period, the precipitation data in the hydrometeorological sequence and the actual evapotranspiration of the region, the available water flux of the period is calculated; The water flux expression is as follows: WA i =P i -AND i +ΔTWSC i In the formula, WA i is the available water flux in the ith cycle; P i is the precipitation data of the ith period; ET i is the actual regional evapotranspiration in the i-th cycle; ΔTWSC i is the change of groundwater resources in the ith period.

3. The method for identifying drought-flood sudden transition events according to claim 1, It is characterized in that Based on the hydrological and meteorological sequence of the period and the change in groundwater resources, the atmospheric evaporation demand corresponding to the period is calculated, including: Based on the hydrological and meteorological sequence of the period, the saturated water vapor pressure, the actual water vapor pressure, the soil heat flux, the average temperature at the target height and the slope of the saturated water vapor pressure curve corresponding to the period are calculated; Based on the preset evaporation demand expression, the atmospheric evaporation demand of the period is calculated by comprehensively considering the saturated water vapor pressure, actual water vapor pressure, soil heat flux, average temperature at the target height, slope of the saturated water vapor pressure curve, net surface radiation in the hydro-meteorological sequence, and wind speed at the target height; The evaporation demand expression is as follows: In the formula, ED i is the atmospheric evaporation demand corresponding to the i-th period; K i is the slope of the saturated water vapor pressure curve corresponding to the i-th cycle; r is the hygrometer constant; U i is the target high wind speed corresponding to the ith period; Rn i is the surface net radiation corresponding to the ith period; G i is the soil heat flux corresponding to the ith period; T i is the average temperature of the target height corresponding to the i-th cycle; es i is the saturated water vapor pressure corresponding to the i-th cycle; ea i is the actual water vapor pressure corresponding to the ith period.

4. The method for identifying drought-flood transition events according to claim 3, It is characterized in that Each hydro-meteorological series also includes the atmospheric temperature series, target high-altitude temperature series and dew-point temperature of the corresponding period; Based on the hydrological and meteorological sequence of the period, the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high average temperature and the slope of the saturated water vapor pressure curve corresponding to the period are calculated, including: Calculate the saturated water vapor pressure, actual water vapor pressure, soil heat flux, target high temperature average and the slope of the saturated water vapor pressure curve corresponding to the period based on the atmospheric temperature sequence, target high temperature sequence and dew point temperature of the period using a preset functional relationship group; The functional relationship group is as follows: G_i=Cs(T_iy-T_(iy-1)) / (△t_i) In the formula, Δt i is the time step of the ith cycle; Cs is the soil heat capacity; T iy is the atmospheric temperature at the end of the ith period; T iy-1 is the atmospheric temperature at the beginning of the ith period; T imax is the target maximum temperature at high altitude in the i-th cycle; T imin is the target high minimum temperature of the i-th cycle; e0 i is the air temperature of the ith cycle; T idew is the dew point temperature of the ith cycle.

5. The method for identifying drought-flood transition events according to claim 1, It is characterized in that Each hydrometeorological series includes the actual regional evapotranspiration for the corresponding period; Based on the available water flux of the period and the atmospheric evaporation demand, the water heat flux residual ratio of the period is calculated, including: Calculating the water-heat flux residual ratio of the period using a preset residual ratio expression, the actual regional evapotranspiration of the period, the available water flux and the atmospheric evaporation demand; The residual ratio expression is as follows: In the formula, WER i is the residual ratio of water heat flux in the ith cycle; WA i is the available water flux in the ith cycle; ED i is the atmospheric evaporation demand corresponding to the i-th period; ET i is the actual regional evapotranspiration in the ith period.

6. The method for identifying drought-flood transition events according to claim 1, It is characterized in that The normal distribution curve is constructed based on each water heat flux residual ratio, including: Each water heat flux residual ratio was detrended and z- sco r e The method is to process each detrended water and heat flux residual ratio to form a normal residual ratio that obeys the standardized normal distribution; Based on each normal residual ratio, a normal distribution curve is plotted.

7. The method for identifying drought-flood transition events according to claim 6, It is characterized in that The use of z- score The method is used to process each detrended water and heat flux residual ratio to form a normal residual ratio that obeys a standardized normal distribution, including: Calculate the mean and standard deviation of each detrended water-heat flux residual ratio; Substitute the mean, standard deviation, and each detrended water and heat flux residual ratio into the preset Z-score expression to calculate the normal residual ratio corresponding to each period; The Z-score expression is as follows: In the formula, SWER i is the normal residual ratio corresponding to the i-th period; WER′ i is the detrended water heat flux residual ratio corresponding to the ith period; μ is the mean of each detrended water heat flux residual ratio; σ is the standard deviation of each detrended water heat flux residual ratio.

8. A device for identifying drought-flood sudden change events, It is characterized in that include: An acquisition module is used to obtain the hydrological and meteorological sequences and groundwater resource changes corresponding to the continuous periods of the target area; A calculation module is used to calculate the available water flux and atmospheric evaporation demand corresponding to each period based on the hydrological and meteorological sequence and groundwater resource changes of the period; and calculate the water-heat flux residual ratio of the period based on the available water flux and atmospheric evaporation demand of the period; A construction module for constructing a normal distribution curve based on the ratio of each water heat flux residual; A determination module, used for determining a data point matching each water heat flux residual ratio on the normal distribution curve; A comparison module, for determining that a drought disaster occurs in the target area in the corresponding period when the probability of the corresponding data point in any period is less than N%; for determining that a waterlogging disaster occurs in the target area in the corresponding period when the probability of the corresponding data point in any period is greater than M%, wherein N is less than M; The judgment module is used to judge whether the period interval between drought and flood in the target area is less than the period threshold. If so, it is determined that a drought-flood sudden transition event occurs in the target area; if not, it is determined that no drought-flood sudden transition event occurs in the target area.

9. A device for identifying drought-flood sudden change events, It is characterized in that including memory and processor; The memory is used to store programs; The processor is used to execute the program to implement each step of the drought-flood rapid transition event identification method as described in any one of claims 1-7.

10. A readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, each step of the method for identifying drought-flood transition events according to any one of claims 1 to 7 is implemented.

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