Method and device for determining key parameters in soil freezing and thawing process

Abstract

The invention provides a soil freezing and thawing process key parameter determination method and device, and relates to the field of geological exploration, and the method comprises the steps: processing hourly historical ground temperature data of a to-be-detected region in a preset time period, obtaining the time and frequency of occurrence of the maximum value and the minimum value of the ground temperature in a single day, calculating the expected value of the time, and calculating the expected value of the time; determining expected moments at which the maximum maximum value and the minimum minimum value appear; and constructing a ground temperature-time function relational expression based on a harmonic function and an expected moment, proposing a new freeze-thaw coefficient calculation formula, drawing a curve graph of the freeze-thaw coefficient changing along with time, and determining a freezing start day, a thawing start day, a freezing period, a thawing period and a freeze-thaw cycle active period corresponding to the to-be-detected region in a preset time period. According to the method, the daily freeze-thaw cycle process of the soil is considered, and the provided freeze-thaw coefficient calculation method can accurately reflect the process, so that the determination of the key parameters in the freeze-thaw process of the soil is more quantitative, and the accuracy and reliability of parameter calculation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of geological exploration, and particularly to a method and device for determining key parameters in the soil freezing and thawing process. Background Art

[0002] With global warming, the cryosphere and its affected ecological environment are facing huge challenges. The hydro-physical processes in permafrost regions are changing, facing problems such as changes in the moisture of the active layer of permafrost and the melting of subsurface ice, and the problem of sharp reduction of water resources is becoming increasingly prominent. The research on permafrost degradation and its hydrological effects has attracted increasing attention. Relevant international research shows that under the background of permafrost degradation, the base flow of rivers in winter and the runoff in the warm season increase significantly, and it is attributed to the runoff generation mechanism of subsurface ice melting, deepening of the active layer, and extension of the melting season. However, how exactly is the water in the active layer and the meltwater of subsurface ice distributed and where does it finally go? What are the spatio-temporal scales of its participation in the hydrological (geological) cycle? What is the contribution of subsurface ice melting to the water resource volume, how will it change, and how will it affect the hydrology, ecology and sustainable development of regional society and economy in cold regions? These related problems remain unresolved. So far in China, the research on the movement of water in the active layer of permafrost regions and subsurface ice is relatively scarce, mainly concentrated in the numerical simulation of ground temperature and ice temperature. Due to the single research method and the inefficiency of field observation, there is a lack of actual observation and data on the movement of water in the active layer and the freezing and thawing process of subsurface ice, and in-depth experiments and long-term monitoring are urgently needed at the small watershed scale. Taking the Qinghai-Tibet Plateau as an example, the Qinghai-Tibet Plateau is located in the central and southern part of the Asian continent, with extensive permafrost distribution, large temperature differences between day and night and between seasons, and freeze-thaw disasters occur frequently, bringing many potential threats to local residential buildings, agricultural and livestock land, engineering construction and operation and maintenance. Carrying out systematic research on the soil freezing and thawing process helps to further understand the local climate change and eco-hydrological process, and can provide scientific reference for human engineering activities such as engineering construction and agricultural production, which has important practical significance. Summary of the Invention

[0003] The purpose of the present invention is to provide a method and device for determining key parameters in the soil freezing and thawing process to solve the problem that it is difficult to accurately and quantitatively determine the key time points in the current soil freezing and thawing process.

[0004] The technical solution of the embodiment of the present application is realized as follows:

[0005] The first aspect of the embodiment of the present application provides a method for determining key parameters in the soil freezing and thawing process, including:

[0006] Processing the hourly historical ground temperature data of the area to be measured within a preset time period to obtain the moments and frequencies of the maximum maximum value and the minimum minimum value of the ground temperature within a single day;

[0007] Based on the time and the expected value of the frequency calculation time, determine the expected time when the maximum maximum value and the minimum minimum value of the ground temperature in a preset time period appear;

[0008] A geothermal-time function relationship is constructed based on a simple harmonic function and the expected time, and the daily freeze-thaw coefficient is determined by using an energy integration method; the freeze-thaw coefficient represents the ratio of the melting amount to the total change, and the total change is the sum of the absolute values ​​of the melting amount and the freezing amount; a curve graph of the freeze-thaw coefficient changing with time is drawn using the freeze-thaw coefficient, and based on the curve graph, the corresponding freezing start date, melting start date, freezing period, melting period and freeze-thaw cycle active period of the measured area within a preset time period are determined.

[0009] Optionally, the hourly historical geothermal data is the hourly average temperature of 0 to 7 cm below the ground surface.

[0010] Optionally, the hourly historical ground temperature data of the measured area within a preset time period is processed to obtain the time and frequency of the maximum and minimum ground temperature in a single day, including:

[0011] Converting the hourly historical ground temperature data into a temperature curve;

[0012] Obtaining all local maximum values ​​and local minimum values ​​in the temperature curve;

[0013] The maximum maximum value and the minimum minimum value of the ground temperature in a single day are selected from the local maximum value and the local minimum value, and the time and frequency of occurrence of the maximum maximum value and the minimum minimum value are recorded.

[0014] Optionally, the local maximum value T part-max (x) satisfies: T(x-1)<T part-max (x)>T(x+1); local minimum value T part-min (x) satisfies: T(x-1)>T part-min (x)<T(x+1); where x is a positive integer, the value range for ordinary years is [1, 8760], and the value range for leap years is [1, 8784]).

[0015] Optional, the maximum value of ground temperature in a single day satisfy: Minimum satisfy: Wherein, d=floor((x-1) / 24)+1, floor represents rounding down, d is a positive integer, and the value range for ordinary years is [1, 365], and the value range for leap years is [1, 366].

[0016] Optionally, calculating the expected value of the moment based on the moment and the frequency, and determining the expected moments when the maximum and minimum values of the ground temperature occur within a preset time period, includes:

[0017] Using the following formula to determine the first expected moment when the maximum value occurs:

[0018]

[0019]

[0020] Using the following formula to determine the second expected moment when the minimum value occurs:

[0021]

[0022]

[0023] Wherein, Y represents the year, represents the first expected moment in year Y, represents the second expected moment in year Y; t1 represents the first expected moment within the preset time period; t2 represents the second expected moment within the preset time period; i is a positive integer, and the value range is [0, 23]; C i is the occurrence frequency when the maximum value occurs at i o'clock in year Y, F i is the occurrence frequency when the minimum value occurs at i o'clock in year Y.

[0024] Optionally, constructing a ground temperature - time function relationship based on the harmonic function and the expected moment, and using the energy integral method to determine the freeze - thaw coefficient of each day, and drawing a curve graph of the freeze - thaw coefficient changing with time, and determining the corresponding start freezing date, start melting date, freezing period, melting period and freeze - thaw cycle active period of the area to be measured within the preset time period based on the curve graph, includes:

[0025] Constructing a daily ground temperature - time function relationship within the research area, the basic structure of the function relationship is a harmonic function, where T (d)max represents the highest temperature on the dth day of the year, T (d)min represents the lowest temperature on the dth day of the year, and the specific expression is as follows:

[0026]

[0027] Determining the freeze - thaw coefficient of each day based on the energy integral principle, where t a represents the first intersection point of the daily ground temperature - time function relationship and the time axis, t b represents the second intersection point of the daily ground temperature - time function relationship and the time axis, and the calculation formula is as follows:

[0028]

[0029]

[0030]

[0031] Optionally, a geothermal - time function relation is constructed based on the simple harmonic function and the expected time, and the freeze - thaw coefficient for each day is determined by using the energy integral method. A curve graph of the freeze - thaw coefficient changing with time is drawn using the freeze - thaw coefficient, and the start freezing date, start melting date, freezing period, melting period, and active freeze - thaw cycle period corresponding to the area to be measured within a preset time period are determined based on the curve graph, including:

[0032] If the freeze - thaw coefficient FTI is equal to 0.5, it indicates that the soil has experienced a daily freeze - thaw cycle on that day, and the freezing amount on that day is equal to the melting amount;

[0033] If FTI is equal to 1, it indicates that the soil has not experienced a freezing process on that day;

[0034] If FTI is equal to 0, it indicates that the soil has not experienced a melting process on that day;

[0035] If the value range of FTI is (0, 0.5), it indicates that the soil has experienced a daily freeze - thaw cycle on that day, and the freezing amount on that day is greater than the melting amount, showing a freezing state;

[0036] If the value range of FTI is (0.5, 1), it indicates that the soil has experienced a daily freeze - thaw cycle on that day, and the melting amount on that day is greater than the freezing amount, showing a melting state.

[0037] The second aspect of the embodiments of the present application provides a device for determining key parameters of the soil freeze - thaw process, including: a data acquisition module, a first determination module, and a second determination module, where

[0038] The data acquisition module is configured to process the hourly historical geothermal data of the area to be measured within a preset time period, and obtain the moments and frequencies when the maximum maximum value and the minimum minimum value of the geothermal temperature occur within a single day;

[0039] The first determination module is configured to calculate the expected value of the moment based on the moment and the frequency, and determine the expected moments when the maximum maximum value and the minimum minimum value of the geothermal temperature occur within the preset time period;

[0040] The second determination module is configured to construct a relationship formula of ground temperature - time function based on a harmonic function and the expected time, and determine the daily freeze - thaw coefficient by using the energy integral method; the freeze - thaw coefficient represents the ratio of the melting amount to the total change amount, and the total change is the sum of the absolute values of the melting amount and the freezing amount; draw a curve graph of the freeze - thaw coefficient changing with time, and determine the start freezing date, start melting date, freezing period, melting period and freeze - thaw cycle active period corresponding to the area to be measured within a preset time period based on the curve graph.

[0041] In the third aspect of the embodiments of the present application, an electronic device is provided, including a processor and a memory; the memory stores a computer program, wherein the computer program, when executed by the processor, implements the method for determining key parameters of the soil freeze - thaw process in the first aspect.

[0042] Compared with the prior art, the beneficial effects brought by the technical solution provided by the present application are:

[0043] The present invention provides a method and device for determining key parameters of the soil freeze - thaw process, processes the hourly historical ground temperature data of the area to be measured within a preset time period, obtains the moments and frequencies when the maximum maximum value and the minimum minimum value of the ground temperature occur within a single day, and then calculates the expected value of the moment to determine the expected moments when the maximum maximum value and the minimum minimum value occur; constructs a relationship formula of ground temperature - time function based on a harmonic function and the expected time, proposes a new calculation formula for the freeze - thaw coefficient, draws a curve graph of the freeze - thaw coefficient changing with time, and determines the start freezing date, start melting date, freezing period, melting period and freeze - thaw cycle active period corresponding to the area to be measured within a preset time period. By considering the daily freeze - thaw cycle process of the soil and the proposed calculation method of the freeze - thaw coefficient can accurately reflect this process, the determination of the key parameters of the soil freeze - thaw process is more quantitative, and the accuracy and reliability of parameter calculation are improved. Description of the Drawings

[0044] Figure 1 It is a schematic flowchart of a method for determining key parameters of the soil freeze - thaw process provided by the embodiments of the present application;

[0045] Figure 2 It is a curve graph of the hourly change of the ground temperature in a certain place in Qinghai Province in 2023 provided by the embodiments of the present application;

[0046] Figure 3 It is a schematic diagram of the distribution of the moments when the maximum maximum value and the minimum minimum value of the ground temperature occur on a single day in a certain place in Qinghai Province in 2023;

[0047] Figure 4 It is a curve graph of the ground temperature - time change in a certain place in Qinghai Province from October 20 to October 21, 2023 provided by the embodiments of the present application;

[0048] Figure 5 The graph of the variation of ground temperature with time at a certain place in Qinghai Province from May 3, 2023 to May 4, 2023 provided by an embodiment of the present application;

[0049] Figure 6 The graph of the variation of ground temperature with time at a certain place in Qinghai Province on November 16, 2021 provided by an embodiment of the present application;

[0050] Figure 7 The graph of the variation of ground temperature with time at a certain place in Qinghai Province on February 18, 2022 provided by an embodiment of the present application;

[0051] Figure 8 The schematic diagram of the calculation principle of the freeze-thaw coefficient provided by an embodiment of the present application;

[0052] Figure 9 The graph of the variation of the freeze-thaw coefficient with time at a certain place in Qinghai Province from August 10, 2022 to October 31, 2024 provided by an embodiment of the present application;

[0053] Figure 10 The schematic structural diagram of a device for determining key parameters in the soil freeze-thaw process provided by an embodiment of the present application;

[0054] Figure 11 The schematic structural diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0055] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present application. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present application. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts of the present application.

[0056] The terms used herein are merely for describing specific embodiments and are not intended to limit the present application. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0057] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0058] Some block diagrams and / or flowcharts are shown in the accompanying drawings. It should be understood that some of the blocks or combinations thereof in the block diagrams and / or flowcharts can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when executed by the processor, these instructions can create a device for implementing the functions / operations illustrated in these block diagrams and / or flowcharts.

[0059] In some embodiments, refer to Figure 1 , Figure 1 which is a schematic flowchart of the method for determining key parameters in the soil freezing and thawing process provided by the embodiments of the present application; the method for determining key parameters in the soil freezing and thawing process provided by the embodiments of the present application includes:

[0060] S110, process the hourly historical ground temperature data of the area to be measured within a preset time period, and obtain the moments and frequencies of the maximum and minimum extreme values of the ground temperature within a single day;

[0061] In some embodiments, the obtained original data is the hourly average temperature at 0-7 cm below the surface of the area to be measured.

[0062] In some embodiments, S110, process the hourly historical ground temperature data of the area to be measured within a preset time period, and obtain the moments and frequencies of the maximum and minimum extreme values of the ground temperature within a single day, including:

[0063] Convert the hourly historical ground temperature data into a temperature curve;

[0064] Obtain all local maximum and local minimum values in the temperature curve;

[0065] Select the maximum and minimum extreme values of the ground temperature within a single day from the local maximum and local minimum values, and record the moments and frequencies of the maximum and minimum extreme values.

[0066] In some embodiments, the local maximum value T part-max (x) satisfies: T(x - 1) < T part-max (x) > T(x + 1); the local minimum value T part-min (x) satisfies: T(x - 1) > T part-min (x) < T(x + 1); where x is a positive integer, and the value range for a common year is [1, 8760], and the value range for a leap year is [1, 8784]).

[0067] In some embodiments, the maximum extreme value of the ground temperature within a single day satisfies: The minimum extreme value satisfies: Wherein, d = floor((x - 1) / 24) + 1, floor represents rounding down, d is a positive integer, and the value range for a common year is [1, 365], and the value range for a leap year is [1, 366].

[0068] In some embodiments, all the moments x corresponding to the maximum maximum values are converted into the real moments t of each day (for example, x = 26 represents 2:00 on the second day of the year, and at this time, t is set to 2, using 2 to represent 2:00), obtaining set A. Similarly, after converting all the moments x corresponding to the minimum minimum values into t, set B is obtained. The frequencies are respectively counted for set A and set B to generate statistical matrices MatA and MatB, and based on this, a bar chart is drawn.

[0069]

[0070]

[0071] Exemplarily, the hourly ground temperature data in the research area for the past 10 years can be obtained, and the ground temperature-time change curve for any year can be drawn. Please refer to Figure 2 , Figure 2 which is the hourly change curve of the ground temperature in a certain place in Qinghai Province in 2023 provided by the embodiment of the present application. By writing Matlab script language, all the local maximum and local minimum values of the ground temperature in the above curve can be searched; based on this, the maximum maximum value and the minimum minimum value of each day are determined, and the occurrence frequencies of the moments when the maximum maximum value of the ground temperature appears and the moments when the minimum minimum value of the ground temperature appears are counted, and a bar chart is drawn. Please refer to Figure 3 , Figure 3 which is the schematic diagram of the distribution of the moments when the single-day maximum maximum value and the minimum minimum value of the ground temperature appear in a certain place in Qinghai Province in 2023.

[0072] S120, calculating the expected value of the moment based on the moment and the frequency, and determining the expected moments when the maximum maximum value and the minimum minimum value of the ground temperature appear within the preset time period.

[0073] Here, the expected values of the moments when the single-day maximum maximum value of the ground temperature appears and the moments when the minimum minimum value of the ground temperature appears for each year can be calculated, and based on this, the data for 10 years are averaged to solve the expected moments when the maximum maximum value and the minimum minimum value of the ground temperature appear within the preset time period.

[0074] In some embodiments, S120, calculating the expected value of the moment based on the moment and the frequency, and determining the expected moments when the maximum maximum value and the minimum minimum value of the ground temperature appear within the preset time period, includes:

[0075] Using the following formula to determine the first expected moment when the maximum maximum value appears:

[0076]

[0077]

[0078] Determine the second expected moment when the minimum minimum value appears by using the following formula:

[0079]

[0080]

[0081] where Y represents the year, represents the first expected moment in year Y, represents the second expected moment in year Y; t1 represents the first expected moment within the preset time period; t2 represents the second expected moment within the preset time period; i is a positive integer, and the value range is [0, 23]; C i is the occurrence frequency when the maximum maximum value in year Y appears at the i-th point, F i is the occurrence frequency when the minimum minimum value in year Y appears at the i-th point.

[0082] First of all, it should be clear that the change of ground temperature between the sun and the earth is regular, approximately a simple harmonic function. The moment when the daily maximum ground temperature appears is basically in the afternoon (corresponding to the moment when the daily maximum maximum air temperature appears), and the moment when the daily minimum ground temperature appears is basically in the morning (corresponding to the moment when the daily minimum minimum air temperature appears), as Figure 4 、 Figure 5 shown, Figure 4 is the ground temperature-time change curve of a certain place in Qinghai Province from October 20th, 2023 to October 21st, 2023 provided by the embodiment of the present application, Figure 5 is the ground temperature-time change curve of a certain place in Qinghai Province from May 3rd, 2023 to May 4th, 2023 provided by the embodiment of the present application. In extremely rare cases, the moment when the daily maximum / minimum ground temperature appears does not occur in the afternoon / morning, as Figure 6 、 Figure 7 shown, Figure 6 is the ground temperature-time change curve of a certain place in Qinghai Province on November 16th, 2021 provided by the embodiment of the present application, Figure 7 is the ground temperature-time change curve of a certain place in Qinghai Province on February 18th, 2022 provided by the embodiment of the present application (after statistics, Figure 6 the corresponding situation occurs 20 - 30 times a year, Figure 7 the situation shown occurs 2 times a year on average), Figure 6 the situation shown has no impact on the subsequent calculation of the freeze-thaw coefficient at all, and Figure 7The probability of the occurrence of this type of situation is extremely low, and it has little impact on the subsequent calculation of the freeze-thaw coefficient. Therefore, it is highly reasonable to construct the subsequent daily ground temperature-time function relationship by equating the occurrence time of the single-day maximum / maximum and minimum / minimum ground temperatures with the occurrence time of the single-day highest / lowest ground temperatures.

[0083] S130. Construct a ground temperature-time function relationship based on a harmonic function and the expected time, and use the energy integration method to determine the daily freeze-thaw coefficient; the freeze-thaw coefficient represents the ratio of the melting amount to the total change amount, and the total change is the sum of the absolute values of the melting amount and the freezing amount; use the freeze-thaw coefficient to draw a curve graph of the freeze-thaw coefficient changing with time, and based on the curve graph, determine the corresponding start freezing date, start melting date, freezing period, melting period, and freeze-thaw cycle active period of the area to be measured within the preset time period.

[0084] In some embodiments, construct a daily ground temperature-time function relationship within the research area. The basic structure of the function relationship is a harmonic function, where T (d)max represents the highest temperature on the dth day of the year, and T (d)min represents the lowest temperature on the dth day of the year. The specific expression is as follows:

[0085]

[0086] Calculate the daily freeze-thaw coefficient based on the energy integration principle. The calculation principle diagram is as Figure 8 shown, Figure 8 which is a schematic diagram of the freeze-thaw coefficient calculation principle provided by the embodiments of the present application. Among them, t a represents the first intersection point of the ground temperature-time function relationship and the time axis, and t b represents the second intersection point of the ground temperature-time function relationship and the time axis. The calculation formula is as follows:

[0087]

[0088]

[0089]

[0090] In some embodiments, S130. Construct a ground temperature-time function relationship based on a harmonic function and the expected time, and use the energy integration method to determine the daily freeze-thaw coefficient; use the freeze-thaw coefficient to draw a curve graph of the freeze-thaw coefficient changing with time, and based on the curve graph, determine the corresponding start freezing date, start melting date, freezing period, melting period, and freeze-thaw cycle active period of the area to be measured within the preset time period, including:

[0091] If the freeze-thaw coefficient FTI is equal to 0.5, it indicates that the soil has experienced a daily freeze-thaw cycle on that day, and the freezing amount on that day is equal to the melting amount;

[0092] If the FTI is equal to 1, it indicates that the soil did not experience a freezing process on that day;

[0093] If the FTI is equal to 0, it indicates that the soil did not experience a thawing process on that day;

[0094] If the value range of the FTI is (0, 0.5), it indicates that the soil experienced a daily freeze-thaw cycle on that day, and the freezing amount on that day was greater than the thawing amount, showing freezing;

[0095] If the value range of the FTI is (0.5, 1), it indicates that the soil experienced a daily freeze-thaw cycle on that day, and the thawing amount on that day was greater than the freezing amount, showing thawing.

[0096] In this embodiment, the freezing period, thawing period, and active freeze-thaw cycle period can be divided on a time scale. The specific determination and division basis are as follows: For a freeze-thaw coefficient-time curve with a certain time length, on the process of the value of the freeze-thaw coefficient decreasing from 1, the first day when the freeze-thaw coefficient drops below 0.5 is taken as the start freezing day of the current year; similarly, on the process of the value of the freeze-thaw coefficient rising from 0, the first day when the freeze-thaw coefficient rises above 0.5 is taken as the start thawing day of the current year. To avoid the influence of random weather, the judgment conditions need to meet the condition of lasting for 3 days, and only the first day that meets the conditions is recorded as the starting time of a certain process. It should be noted that the time interval between the start freezing day of a certain year and the start thawing day of the second year is defined as the freezing period; the time interval between the start thawing day of a certain year and the start freezing day of the current year is defined as the thawing period. The active freeze-thaw cycle period (the freeze-thaw coefficient is near 0.5) can be qualitatively circled at the time junction of the freezing period and the thawing period. Figure 9 It is the change curve graph of the freeze-thaw coefficient in a certain place in Qinghai Province from August 10, 2022 to October 31, 2024 provided by the embodiment of the present application.

[0097] In the embodiment of the present invention, by processing the hourly historical ground temperature data of the area to be measured within a preset time period, the moments and frequencies of the maximum and minimum ground temperatures within a single day are obtained, and then the expected value of the moment is calculated to determine the expected moments of the maximum and minimum ground temperatures; based on the harmonic function and the expected moments, a ground temperature-time function relationship is constructed, a new freeze-thaw coefficient calculation formula is proposed, a change curve graph of the freeze-thaw coefficient with time is drawn, and the start freezing day, start thawing day, freezing period, thawing period, and active freeze-thaw cycle period corresponding to the area to be measured within the preset time period are determined. By considering the daily freeze-thaw cycle process of the soil and the proposed freeze-thaw coefficient calculation method can accurately reflect this process, the determination of the key parameters of the soil freeze-thaw process is made more quantitative, and the accuracy and reliability of the parameter calculation are improved.

[0098] In some embodiments, please refer to Figure 10 , Figure 10Schematic structural diagram of a device for determining key parameters in the soil freezing and thawing process provided by an embodiment of the present application; An embodiment of the present application provides a device 1000 for determining key parameters in the soil freezing and thawing process, including: a data acquisition module 1010, a first determination module 1020, and a second determination module 1030, where,

[0099] The data acquisition module 1010 is configured to process the hourly historical ground temperature data of the area to be measured within a preset time period, and obtain the moments and frequencies when the maximum maximum value and the minimum minimum value of the ground temperature occur within a single day;

[0100] The first determination module 1020 is configured to calculate the expected value of the moment based on the moment and the frequency, and determine the expected moments when the maximum maximum value and the minimum minimum value of the ground temperature occur within the preset time period;

[0101] The second determination module 1030 is configured to construct a ground temperature-time function relationship based on a harmonic function and the expected moment, and determine the freezing and thawing coefficient of each day by using the energy integration method; The freezing and thawing coefficient represents the ratio of the melting amount to the total change amount, and the total change is the sum of the absolute values of the melting amount and the freezing amount; Use the freezing and thawing coefficient to draw a curve of the freezing and thawing coefficient changing with time, and determine the corresponding start freezing date, start melting date, freezing period, melting period, and freezing and thawing cycle active period of the area to be measured within the preset time period based on the curve.

[0102] In some embodiments, the hourly historical ground temperature data is the hourly average temperature from 0 to 7 cm below the ground surface.

[0103] In some embodiments, the data acquisition module 1010 is specifically configured to:

[0104] Convert the hourly historical ground temperature data into a temperature curve;

[0105] Obtain all local maximum values and local minimum values in the temperature curve;

[0106] Screen out the maximum maximum value and the minimum minimum value of the ground temperature within a single day from the local maximum values and local minimum values, and record the moments and frequencies when the maximum maximum value and the minimum minimum value occur.

[0107] In some embodiments, the local maximum value T part-max (x) satisfies: T(x - 1) < T part-max (x) > T(x + 1); The local minimum value T part-min (x) satisfies: T(x - 1) > T part-min (x) < T(x + 1); where x is a positive integer, and the value range for a common year is [1, 8760], and the value range for a leap year is [1, 8784]).

[0108] In some embodiments, the maximum maximum value of the ground temperature within a single day Satisfy: Minimum minimum value Satisfy: Where d = floor((x - 1) / 24)+1, floor represents rounding down, d is a positive integer, the value range for a common year is [1, 365], and the value range for a leap year is [1, 366].

[0109] In some embodiments, the first determination module 1020 is specifically configured to:

[0110] Determine the first expected moment when the maximum maximum value appears by using the following formula:

[0111]

[0112]

[0113] Determine the second expected moment when the minimum minimum value appears by using the following formula:

[0114]

[0115]

[0116] Where Y represents the year, represents the first expected moment in year Y, represents the second expected moment in year Y; t1 represents the first expected moment within a preset time period; t2 represents the second expected moment within a preset time period; i is a positive integer, and the value range is [0, 23]; C i is the occurrence frequency when the maximum maximum value appears at i o'clock in year Y, F i is the occurrence frequency when the minimum minimum value appears at i o'clock in year Y.

[0117] In some embodiments, the second determination module 1030 is configured to:

[0118] Construct a solar-terrestrial temperature - time function relationship within the research area. The basic structure of the function relationship is a simple harmonic function, where T (d)max represents the highest temperature on the dth day of the year, T (d)min represents the lowest temperature on the dth day of the year. The specific expression is as follows:

[0119]

[0120] Determine the freeze-thaw coefficient for each day based on the energy integration principle, where t a represents the first intersection point of the solar-terrestrial temperature - time function relationship and the time axis, t b represents the second intersection point of the solar-terrestrial temperature - time function relationship and the time axis. The calculation formula is as follows:

[0121]

[0122]

[0123]

[0124] In some embodiments, the second determination module 1030 is configured to:

[0125] If the freeze-thaw index FTI is equal to 0.5, it indicates that the soil has experienced a daily freeze-thaw cycle on the current day, and the freezing amount on the current day is equal to the thawing amount;

[0126] If FTI is equal to 1, it indicates that the soil has not experienced a freezing process on the current day;

[0127] If FTI is equal to 0, it indicates that the soil has not experienced a thawing process on the current day;

[0128] If the value range of FTI is (0, 0.5), it indicates that the soil has experienced a daily freeze-thaw cycle on the current day, and the freezing amount on the current day is greater than the thawing amount, showing freezing;

[0129] If the value range of FTI is (0.5, 1), it indicates that the soil has experienced a daily freeze-thaw cycle on the current day, and the thawing amount on the current day is greater than the freezing amount, showing thawing.

[0130] The device for determining key parameters of the soil freeze-thaw process provided by the embodiments of the present application can implement each process in the corresponding embodiments of the above-mentioned method for determining key parameters of the soil freeze-thaw process. To avoid repetition, it will not be elaborated here.

[0131] It should be noted that the device for determining key parameters of the soil freeze-thaw process provided by the embodiments of the present application and the method for determining key parameters of the soil freeze-thaw process provided by the embodiments of the present application are based on the same application concept. Therefore, the specific implementation of this embodiment can refer to the implementation of the foregoing method for determining key parameters of the soil freeze-thaw process, and the repeated parts will not be elaborated.

[0132] In some embodiments, please refer to Figure 11 , Figure 11 is a schematic structural diagram of an electronic device provided by an embodiment of the present application. An electronic device 1100 provided by an embodiment of the present application includes a processor 1110 and a memory 1120; the memory 1120 stores a computer program, wherein the computer program, when executed by the processor, implements the above-mentioned method for determining key parameters of the soil freeze-thaw process.

[0133] Specifically, the processor 1110 may include, for example, a general - purpose microprocessor, an instruction - set processor, and / or a related chipset, and / or a dedicated microprocessor (such as an application - specific integrated circuit (ASIC)), and so on. The processor 1110 may also include on - board memory for caching purposes. The processor 1110 may be a single processing unit or multiple processing units for performing different actions of the method flow according to the embodiments of the present application.

[0134] The memory 1120 can be, for example, any medium capable of containing, storing, transmitting, propagating, or transporting instructions. For example, the memory 1120 may include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, components, or propagation media. Specific examples of the memory 1120 include: magnetic storage devices, such as magnetic tapes or hard disk drives (HDDs); optical storage devices, such as compact discs (CD - ROMs); it can also be, for example, random access memory (RAM) or flash memory; and / or wired / wireless communication links.

[0135] The present application also provides a computer - readable medium, on which a computer program is stored. When the program is executed by a processor, it implements the above - mentioned method for determining key parameters of the soil freeze - thaw process. The computer - readable medium may be included in the device / device / system described in the above - mentioned embodiments; or it may exist separately and not be assembled into the device / device / system. The above - mentioned computer - readable medium carries one or more programs, and when the above - mentioned one or more programs are executed, the method according to the embodiments of the present application is implemented.

[0136] According to an embodiment of the present application, a computer-readable medium may be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. A computer-readable storage medium may, for example, but not be limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium that contains or stores a program, and the program may be used by or in conjunction with an instruction execution system, apparatus, or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, and the computer-readable medium may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted by any appropriate medium, including but not limited to: wireless, wired, optical fiber cable, radio frequency signal, etc., or any suitable combination of the above.

[0137] Those skilled in the art will understand that the features recited in the various embodiments and / or claims of the present application may be combined and / or combined in various ways, even if such combinations or combinations are not explicitly recited in the present application. In particular, without departing from the spirit and teachings of the present application, the features recited in the various embodiments and / or claims of the present application may be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present application. Therefore, the scope of the present application should not be limited to the above embodiments, but should be determined not only by the appended claims, but also by the equivalents of the appended claims.

Claims

1. A method for determining key parameters in the soil freeze-thaw process, characterized in that, Including: Processing the hourly historical ground temperature data of the area to be measured within a preset time period to obtain the moments and frequencies of the maximum and minimum ground temperatures within a single day; Calculating the expected value of the moment based on the moment and the frequency, and determining the expected moments of the maximum and minimum ground temperatures within the preset time period; Constructing a ground temperature-time function relationship based on a harmonic function and the expected moment, and determining the daily freeze-thaw coefficient by using an energy integration method; the freeze-thaw coefficient represents the ratio of the melting amount to the total change amount, and the total change is the sum of the absolute values of the melting amount and the freezing amount; Drawing a curve graph of the freeze-thaw coefficient changing with time by using the freeze-thaw coefficient, and determining the corresponding start freezing date, start melting date, freezing period, melting period and freeze-thaw cycle active period of the area to be measured within the preset time period based on the curve graph.

2. The method for determining key parameters in the soil freeze-thaw process according to claim 1, wherein The hourly historical ground temperature data is the hourly average temperature from 0 to 7 cm below the ground surface.

3. The method for determining key parameters in the soil freezing and thawing process according to claim 1, wherein The processing of the hourly historical ground temperature data of the area to be measured within a preset time period to obtain the moments and frequencies of the maximum and minimum ground temperatures within a single day includes: Converting the hourly historical ground temperature data into a temperature curve; Obtaining all local maximum values and local minimum values in the temperature curve; Selecting the maximum and minimum ground temperatures within a single day from the local maximum values and the local minimum values and recording the moments and frequencies of the maximum and minimum ground temperatures.

4. The method for determining key parameters in the soil freezing and thawing process according to claim 3, characterized in that The local maximum value T part-max (x) satisfies: T(x - 1) < T part-max (x) > T(x + 1); The local minimum value T part-min (x) satisfies: T(x - 1) > T part-min (x) < T(x + 1); where x is a positive integer, and the value range for common years is [1, 8760], and the value range for leap years is [1, 8784]).

5. The method for determining key parameters in the soil freeze-thaw process according to claim 1 or 3, characterized in that, The maximum maximum value of the daily in - ground temperature Satisfy: The minimum minimum value Satisfy: Where \(d = \text{floor}((x - 1) / 24)+1\), \(\text{floor}\) represents rounding down, \(d\) is a positive integer, the value range for a common year is \([1,365]\), and the value range for a leap year is \([1,366]\).

6. The method for determining key parameters in the soil freezing and thawing process according to claim 1, characterized in that Calculating the expected value of the moment based on the hourly historical ground temperature data and determining the expected moments of the maximum and minimum ground temperatures within the preset time period includes: Using the following formula to determine the first expected moment of the maximum value: Using the following formula to determine the second expected moment of the minimum value: Among them, Y represents the year, represents the first desired moment in year Y, represents the second desired moment in year Y; t1 represents the first desired moment within the preset time period; t2 represents the second desired moment within the preset time period; i is a positive integer, and its value range is [0, 23]; C i is the occurrence frequency when the maximum maximum value in year Y appears at i o'clock, F i is the occurrence frequency when the minimum minimum value in year Y appears at i o'clock.

7. The method for determining key parameters in the soil freeze-thaw process according to claim 1, characterized in that The constructing a ground temperature-time function relationship based on a harmonic function and the expected moment, and determining the daily freeze-thaw coefficient by using an energy integration method, drawing a curve graph of the freeze-thaw coefficient changing with time by using the freeze-thaw coefficient, and determining the corresponding start freezing date, start melting date, freezing period, melting period and freeze-thaw cycle active period of the area to be measured within the preset time period includes: Construct the daily ground temperature-time function relationship within the study area. The basic structure of the function relationship is a simple harmonic function, where T (d)max represents the highest temperature on the dth day of the year, and T (d)min represents the lowest temperature on the dth day of the year. The specific expression is as follows: Determine the daily freeze-thaw coefficient based on the energy integral principle, where t a represents the first intersection point of the daily ground temperature-time function relation with the time axis, and t b represents the second intersection point of the daily ground temperature-time function relation with the time axis. The calculation formula is as follows:

8. The method for determining key parameters in the soil freeze-thaw process according to claim 1, characterized in that The constructing a ground temperature-time function relationship based on a harmonic function and the expected moment, and determining the daily freeze-thaw coefficient by using an energy integration method, drawing a curve graph of the freeze-thaw coefficient changing with time by using the freeze-thaw coefficient, and determining the corresponding start freezing date, start melting date, freezing period, melting period and freeze-thaw cycle active period of the area to be measured within the preset time period includes: If the freeze-thaw coefficient FTI is equal to 0.5, it indicates that the soil has experienced a daily freeze-thaw cycle on that day, and the freezing amount on that day is equal to the melting amount; If FTI is equal to 1, it indicates that the soil has not experienced a freezing process on that day; If FTI is equal to 0, it indicates that the soil has not experienced a melting process on that day; If the value range of FTI is (0, 0.5), it indicates that the soil has experienced a daily freeze-thaw cycle on that day, and the freezing amount on that day is greater than the melting amount, showing freezing; When the value range of FTI is (0.5, 1), it indicates that the soil has experienced daily freeze-thaw cycles on the same day, and the melting amount on the same day is greater than the freezing amount, showing melting.

9. An apparatus for determining key parameters during the soil freeze-thaw process, characterized in that, Including: A data acquisition module, a first determination module, and a second determination module, where The data acquisition module is configured to process the hourly historical ground temperature data of the area to be measured within a preset time period, and obtain the moments and frequencies when the maximum and minimum extreme values of the ground temperature occur within a single day; The first determination module is configured to calculate the expected value of the moment based on the moment and the frequency, and determine the expected moments when the maximum and minimum extreme values of the ground temperature occur within the preset time period; The second determination module is configured to construct a ground temperature-time function relationship based on a harmonic function and the expected moment, and determine the freeze-thaw coefficient of each day by using the energy integration method; the freeze-thaw coefficient represents the ratio of the melting amount to the total change amount, and the total change is the sum of the absolute values of the melting amount and the freezing amount; use the freeze-thaw coefficient to draw a curve of the freeze-thaw coefficient changing with time, and determine the corresponding start freezing date, start melting date, freezing period, melting period, and freeze-thaw cycle active period of the area to be measured within the preset time period based on the curve.

10. An electronic device, comprising a processor and a memory; the memory stores a computer program, wherein, When the computer program is executed by the processor, it implements the method for determining key parameters of the soil freeze-thaw process according to any one of claims 1 to 8.

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