Method and equipment for determining influence degree of drought on base flow change and medium

Abstract

The invention discloses a method and equipment for determining the influence degree of drought on base flow change and a medium. The method comprises the following steps: acquiring first historical hydrological data of a target drainage basin in a non-drought period; a physical formula for the base flow is determined, and effective water storage capacity parameters and evaporation efficiency parameters in the physical formula are calibrated through first historical hydrological data; acquiring second historical hydrological data of the target drainage basin in the drought period, wherein the second historical hydrological data comprises second historical base flow, second historical precipitation and second historical potential evaporation; and determining the second historical precipitation amount and the predicted base flow amount corresponding to the second historical potential evaporation amount by using a physical formula, and further determining the influence degree of drought on the base flow change in the target drainage basin. According to the method, the influence of drought on the base flow change can be accurately quantified, and effective data support is provided for reasonable planning and design of a water resource system.

Description

Technical Field

[0001] The present application relates to the technical field of hydrological research, and in particular to a method, device, and medium for determining the impact of drought on base flow changes. Background Art

[0002] The assumption of the consistency of the natural water cycle is the basis for the planning and design of water resource systems. The assumption of the consistency of the water cycle means that the basin structure and hydrological data statistical characteristics of the basin will remain unchanged in the future.

[0003] However, with the long-term drought in the basin, drought may have an impact on the basin's hydrological processes. For example, drought may change the basin's base flow, causing the consistency assumptions of the water cycle to change and the planning and design of the water resources system to be unreasonable.

[0004] Therefore, how to accurately quantify the impact of drought on baseflow changes is of great significance for the rational planning and design of water resource systems. Summary of the Invention

[0005] The embodiments of the present application provide a method, device, and medium for determining the impact of drought on baseflow changes, aiming to accurately quantify the impact of drought on baseflow changes and provide effective data support for the rational planning and design of water resource systems.

[0006] In one aspect, the present application provides a method for determining the impact of drought on baseflow changes, the method comprising: Acquiring first historical hydrological data of the target watershed during a non-drought period, wherein the first historical hydrological data includes a first historical base flow, a first historical precipitation, and a first historical potential evaporation; Determining a physical formula for base flow, wherein the physical formula includes an effective water storage capacity parameter and an evaporation efficiency parameter, and the effective water storage capacity parameter and the evaporation efficiency parameter are calibrated using the first historical hydrological data; Acquiring second historical hydrological data of the target watershed during a drought period, wherein the second historical hydrological data includes a second historical base flow, a second historical precipitation, and a second historical potential evaporation; Determine the predicted base flow corresponding to the second historical precipitation and the second historical potential evaporation using the physical formula; The impact of drought on baseflow changes in the target watershed is determined based on the predicted baseflow, the second historical baseflow, and the first historical baseflow.

[0007] In some embodiments, the impact of drought on the baseflow change in the target watershed includes: the actual change in baseflow flow during the drought period compared to the non-drought period, the impact of baseflow inconsistency caused by long-term drought on the baseflow change in the target watershed, and the impact of changes in meteorological elements during long-term drought on the baseflow change in the target watershed.

[0008] In some embodiments, the actual change in baseflow during the drought period compared to the non-drought period is determined based on a first difference between the second historical baseflow and the first historical baseflow. The influence degree of baseflow abortion inconsistency caused by long-term drought on baseflow change in the target watershed is determined based on a second difference between the predicted baseflow and the second historical baseflow; The degree of influence of changes in meteorological elements during a long-term drought on changes in base flow in the target watershed is determined based on a difference between the first difference and the second difference.

[0009] In some embodiments, the influence of baseflow abortion inconsistency caused by long-term drought on baseflow changes in the target watershed is determined based on the ratio of the second difference to the first difference.

[0010] In some embodiments, before obtaining the first historical hydrological data of the target watershed during the non-drought period, the method further includes: In the preset watersheds, the target watershed having a drought period with a duration greater than a preset length is determined.

[0011] In some embodiments, determining the predicted baseflow corresponding to the second historical precipitation and the second historical potential evaporation using the physical formula includes: Using the second historical precipitation as the precipitation in the physical formula, and using the second historical potential evaporation as the potential evaporation in the physical formula, to determine a value of base flow in the physical formula; The value of the base flow in the physical formula is used as the value of the predicted base flow corresponding to the second historical precipitation and the second historical potential evaporation.

[0012] In some embodiments, the physical formula includes the relationship between the drought index, the basin retention index, the base flow index and the evaporation efficiency parameter, wherein the drought index includes the ratio between potential evaporation and precipitation, the basin retention index includes the ratio between the effective water storage capacity parameter and precipitation, and the base flow index includes the ratio between base flow and precipitation.

[0013] In some embodiments, the physical formula includes the following formula:

[0014] Among them, Q b is the base flow, P is the precipitation, S p is the effective water storage capacity parameter, E p is the potential evaporation capacity, and α is the evaporation efficiency parameter.

[0015] In another aspect, an embodiment of the present application provides a device for determining the impact of drought on baseflow changes, comprising: A first acquisition module is configured to acquire first historical hydrological data of the target watershed during a non-drought period, wherein the first historical hydrological data includes a first historical base flow, a first historical precipitation, and a first historical potential evaporation; a first determination module, configured to determine a physical formula for base flow, wherein the physical formula includes an effective water storage capacity parameter and an evaporation efficiency parameter, wherein the effective water storage capacity parameter and the evaporation efficiency parameter are calibrated using the first historical hydrological data; A second acquisition module is configured to acquire second historical hydrological data of the target watershed during the drought period, wherein the second historical hydrological data includes a second historical base flow, a second historical precipitation, and a second historical potential evaporation; A second determination module is configured to determine a predicted base flow corresponding to the second historical precipitation and the second historical potential evaporation using the physical formula; The third determination module is configured to determine the impact of drought on base flow changes in the target watershed based on the predicted base flow, the second historical base flow, and the first historical base flow.

[0016] On the other hand, the present application further provides a computer device, comprising: one or more processors; Memory; and One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the processor to implement the steps in any one of the methods for determining the impact of drought on baseflow change.

[0017] On the other hand, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program is loaded by a processor to execute the steps in any one of the methods for determining the degree of influence of drought on baseflow change.

[0018] On the other hand, the present application also provides a computer program product, including a computer program or instructions, which are executed by a processor to implement the method for determining the impact of drought on base flow change as described in any of the above items.

[0019] The embodiments of the present application provide a method, device, and medium for determining the impact of drought on baseflow changes. The method calibrates the effective water storage capacity parameter and evaporation efficiency parameter in a physical formula for baseflow based on first historical hydrological data of a target watershed during a non-drought period. The physical formula is then used to determine the predicted baseflow corresponding to the second historical precipitation and second historical potential evaporation of the target watershed during the drought period. Based on the predicted baseflow, the second historical baseflow, and the first historical baseflow, the impact of drought on baseflow changes in the target watershed is determined. This embodiment accurately quantifies the impact of drought on baseflow changes by determining a physical formula for baseflow that includes the effective water storage capacity parameter and the evaporation efficiency parameter, and using the physical formula for baseflow, thereby providing effective data support for the rational planning and design of water resource systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a flow chart of an embodiment of a method for determining the impact of drought on base flow change provided in the embodiments of the present application; Figure 2 1 is a schematic diagram of the attribution decomposition of base flow changes in the target watershed provided in the embodiments of the present application; Figure 3 Schematic diagram of the influence of baseflow abortion inconsistency caused by long-term drought on baseflow changes in the target watershed, and the influence of changes in meteorological factors during long-term drought on baseflow changes in the target watershed, provided in the embodiments of the present application; Figure 4 It is a diagram showing the frequency cumulative distribution of the simulation effects of different simulation methods for predicting base flow on multiple target watersheds; Figure 5 This is a schematic diagram of the terminal structure of an embodiment of the computer device provided in the embodiments of the present application.

[0022] in, Figure 2 、 Figure 3 as well as Figure 4 For color pictures, different colors are used to distinguish different objects in the picture. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. In the description of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In the present application, the term "in some embodiments" is used to mean "used as an example, illustration or explanation". Any embodiment described as "in some embodiments" in the present application is not necessarily to be interpreted as being more preferred or more advantageous than other embodiments.

[0024] It should be noted that since the system of the embodiment of the present application is executed in a computer device, the processing objects of each computer device exist in the form of data or information. For example, time is actually time information. It can be understood that if size, quantity, position, etc. are mentioned in subsequent embodiments, the corresponding data exists for the computer device to process. The details will not be repeated here.

[0025] In related technologies, the statistical characteristics of the hydrological data and the structure of the basin will change with climate change. The consistency of the basin structure means that the impact of predicted climate change on the basin runoff mechanism will be similar to the impact observed in the past. Because the impact of human activities on the basin structure is usually fully considered, the impact of natural changes and variability is not considered enough. Multi-year droughts in some areas have been shown to change the response of basin hydrology to changes in climatic conditions, such as changes in the relationship between precipitation and runoff flow, and the failure of precipitation-runoff flow models to simulate drought periods when using parameters from non-drought periods.

[0026] During multi-year droughts, baseflow plays a critical role in maintaining river flow within a watershed. As components of total runoff, baseflow and rapid runoff exhibit distinct responses to climate change and land cover change. Clarifying the dynamics of total runoff and its components during droughts is crucial for a comprehensive understanding of the adaptation strategies of hydrological systems to drought. During multi-year droughts, changes in watershed structure (including vegetation, soil, and groundwater) alter the response of watershed hydrology to changing climatic conditions and, in turn, alter the mechanisms of runoff generation (including total runoff and its components) during droughts. For example, drought-induced tree mortality may lead to a decrease in total runoff. Low runoff coefficients (the ratio of runoff to precipitation) are observed in most watersheds due to changes in water storage capacity during prolonged droughts. Groundwater depletion during prolonged droughts also contributes to heterogeneity in runoff and its components.

[0027] Practical approaches to assessing the impact of drought on the inconsistency of total basin flow can be achieved using regression models, hydrological models, precipitation-runoff models, and the Budyko framework. Compared with hydrological models, the Budyko framework, precipitation-runoff models, and regression models offer simpler models and can more intuitively reveal inconsistencies. However, when attributing changes in basin hydrology using regression models, the impact of drought on baseflow changes is more uncertain than its impact on total basin flow and rapid runoff. This means that the accuracy of the quantitative results when quantifying the impact of drought on baseflow changes is low.

[0028] In this regard, the embodiments of the present application provide a method, device, and medium for determining the impact of drought on baseflow changes. By determining a physical formula for baseflow, which includes an effective water storage capacity parameter and an evaporation efficiency parameter, the physical formula for baseflow is used to accurately quantify the impact of drought on baseflow changes, providing effective data support for the rational planning and design of water resource systems.

[0029] Reference Figure 1 In one embodiment, a method for determining the impact of drought on baseflow changes includes: 101. Obtain first historical hydrological data of the target watershed during a non-drought period, where the first historical hydrological data includes first historical base flow, first historical precipitation, and first historical potential evaporation.

[0030] In an embodiment of the present application, the multiple target basins may be multiple basins recorded in a regional big data sample (CAMELS). The first historical hydrological data for each target basin during a non-drought period is the actual hydrological data of the target basin during the non-drought period. This actual hydrological data can be extracted, for example, from historical data recorded by the Global Runoff Data Center. The first historical baseflow, first historical precipitation, and first historical potential evaporation of the target basin are the actual baseflow, actual precipitation, and actual potential evaporation of the target basin during the non-drought period, respectively. The first historical baseflow of the target basin is obtained by segmenting the total basin flow of the target basin using a preset digital filtering algorithm (e.g., the Lyne-Hollick (LH) method).

[0031] In some embodiments of the present application, the process of screening the target watershed is described. Specifically, before obtaining the first historical hydrological data of the target watershed in the non-drought period, it may also include: determining, in the preset watershed, a target watershed with a drought period that is longer than a preset length. The preset watershed may be a watershed recorded by a regional big data sample (CAMELS). When the drought period in the preset watershed is longer than the preset length, it indicates that the preset watershed is in a long-term drought (e.g., multi-year drought), that is, an arid climate. In this way, for each target watershed, the impact of the baseflow abortion inconsistency caused by the long-term drought on the baseflow change in the target watershed will be determined more accurately.

[0032] 102. Determine a physical formula for base flow, wherein the physical formula includes an effective water storage capacity parameter and an evaporation efficiency parameter, and the effective water storage capacity parameter and the evaporation efficiency parameter are calibrated using the first historical hydrological data.

[0033] In the embodiments of the present application, the physical formula for baseflow includes an effective water storage capacity parameter and an evaporation efficiency parameter. These parameters are calibrated using the first historical baseflow, first historical precipitation, and first historical potential evaporation of the target watershed. Specifically, the physical formula records the physical relationship between baseflow, precipitation, potential evaporation, evaporation efficiency, and the effective water storage capacity parameter. Therefore, the first historical baseflow (as baseflow), first historical precipitation (as precipitation), and first historical potential evaporation (as potential evaporation) of the target watershed can be substituted into the physical formula. A genetic algorithm can then be used to determine the values of the effective water storage capacity and evaporation efficiency parameters in the physical formula, thereby calibrating the effective water storage capacity and evaporation efficiency parameters in the physical formula and obtaining the physical formula for baseflow. Specific details of this physical formula are described below.

[0034] 103. Obtain second historical hydrological data of the target watershed during the drought period, where the second historical hydrological data includes a second historical base flow, a second historical precipitation, and a second historical potential evaporation.

[0035] In the embodiment of the present application, the specific connotation of the second historical hydrological data of the target basin during the drought period can refer to the first historical hydrological data of the target basin during the non-drought period, and will not be repeated here.

[0036] 104. Use physical formulas to determine the predicted base flow corresponding to the second historical precipitation and the second historical potential evaporation.

[0037] In the embodiment of the present application, the predicted base flow refers to the predicted value of the base flow, that is, the base flow is predicted based on the second historical precipitation and the second historical potential evaporation of the target basin during the drought period.

[0038] In some embodiments of the present application, baseflow prediction is implemented based on the aforementioned physical formula. Specifically, using the physical formula to determine the predicted baseflow corresponding to the second historical precipitation and the second historical potential evaporation can include: using the second historical precipitation as the precipitation in the physical formula, and using the second historical potential evaporation as the potential evaporation in the physical formula, and calculating the baseflow in combination with the effective water storage capacity parameter and the evaporation efficiency parameter in the physical formula to determine the value of the baseflow in the physical formula; and using the value of the baseflow in the physical formula as the value of the predicted baseflow corresponding to the second historical precipitation and the second historical potential evaporation, thereby achieving prediction of the baseflow of the target watershed during the drought period.

[0039] In some embodiments of the present application, the physical formula includes the relationship between the drought index, the basin retention index, the base flow index and the evaporation efficiency parameter, wherein the drought index includes the ratio between potential evaporation and precipitation, the basin retention index includes the ratio between the effective water storage capacity parameter and precipitation, and the base flow index includes the ratio between base flow and precipitation.

[0040] In some embodiments of the present application, the physical formula may include, for example:

[0041] Among them, Q b is the base flow, P is the precipitation, E p is the potential evaporation capacity, α is the evaporation efficiency parameter, S p is the effective water storage capacity parameter. It can be seen that the physical formula for base flow realizes the physical relationship description of base flow flow, precipitation, potential evaporation, evaporation efficiency parameter and effective water storage capacity parameter.

[0042] In some embodiments of the present application, the physical formula can be implemented based on the Budyko framework. Specifically, the "limit concept" in the Budyko framework is first described: In terms of basin hydrology, the Budyko framework takes into account the actual evaporation E a The water supply (usually precipitation P) and energy demand (usually potential evaporation E) p ), which can simulate the long-term total flow Q and actual evaporation E of the basin a The concept of "limit" as the basic theory of Budyko framework is the actual evaporation E a Two theoretical limits are set. Mathematically, the concept of "limit" can be expressed as: Under extremely dry conditions, E a / P→1, when E p / P→∞; Under extremely humid conditions, E a →E p , when E p / P→0.

[0043] That is, under extreme drought conditions, when evaporation is limited by precipitation P, the actual evaporation E a will gradually approach the precipitation P. Under extremely humid conditions, when evaporation is limited by energy demand, the actual evaporation E a will gradually approach the potential evaporation E p The concept of "limit" of evaporation can be extended to apply to the basin precipitation retention CR. The precipitation P of the target basin can be divided into surface runoff flow Q s and basin precipitation retention CR (i.e. P = Q s +CR). CR also satisfies the concept of “limit” and can be defined as: Under extreme drought conditions, CR / P→1, when CR0 / P→∞; Under extremely humid conditions, CR→CR0, when CR0 / P→0.

[0044] Where, the demand limit CR0 of CR is the effective water storage capacity parameter S of the target basin p and potential evaporation E p The water supply limit of CR is P. The control effect of CR0 / P on CR is similar to the drought index (E p / P) to the actual evaporation amount E a control effect.

[0045] Next, based on the concept of "limit," a physical formula for baseflow is derived. This physical formula is called the BFC (Budyko-Fu constraint) curve. The BFC curve is used to describe the spatial variation of multi-year average baseflow.

[0046] Based on the concept of "limit", the total flow coefficient of the basin (Q / P) and the surface runoff coefficient (Q s The calculation of base flow index (Q b / P) can be calculated as Q / PQ s / P.

[0047] E a / P satisfies the Budyko curve, E a The calculation of / P satisfies the Fu formula. The parameter that needs to be calibrated in the Fu formula is a1. The Fu formula can be expressed as:

[0048] When changes in basin water storage can be ignored, Q / P can be calculated as 1-E a / P, we get:

[0049] Here, a1 is a parameter that requires calibration and represents the control effect of watershed attribute data on evaporation. The parameter a1 ranges from [1 to ∞]. A higher a1 indicates greater evaporation efficiency. Specifically, given a given amount of precipitation and potential evaporation, a greater actual evaporation results in a smaller total discharge coefficient.

[0050] Q s The calculation of / P is based on the precipitation retention coefficient (CR / P) of the target basin, that is, Q s / P=1-CR / P. CR / P is also calculated using the Fu formula. Assuming that CR satisfies the Budyko curve, the parameter that needs to be calibrated in the corresponding formula is a2, and the mathematical equation for estimating CR / P is:

[0051] Q s / P can be calculated as 1-CR / P:

[0052] Where a2 is a parameter that needs to be calibrated, representing the watershed attribute data (except the effective water storage capacity parameter S p The larger the a2 value, the more precipitation retention and less surface runoff will result. As mentioned above, S p It is the effective water storage capacity parameter of the target basin, which is defined as the maximum amount of water that the target basin can hold after a precipitation event.

[0053] Q b / P is calculated as Q / PQ s / P:

[0054] Under conditions where the effective storage capacity parameter is very limited (e.g., impervious watersheds), the water available to generate baseflow is close to zero, and the baseflow flow is also close to zero, that is: Q b / P→0, when S p / P→0.

[0055] Therefore, when (E p +S p ) / P approaches E p / P(i.e. S p / P→0), Q s / P should be close to Q / P so that Q b / P→0. To satisfy this boundary condition, parameter a1 must be equal to parameter a2. Therefore, Q b The formula for / P can be written as:

[0056] Where α is a new parameter, namely the evaporation efficiency parameter, which reflects the secondary control of basin attribute data on base flow. The value range of α is [1, ∞]. It can be seen that Q b The formula of / P is simplified. In addition, since both a1 and a2 reflect the secondary control of basin properties on baseflow, simplifying a1=a2 has little effect on the shape of the BFC curve. It can be seen from the BFC curve that the baseflow index (Q b / P) is the drought index (E p / P) and watershed retention index (S p / P) function. p / P and S p The sum of P and E represents the target basin’s ability to store precipitation for baseflow and evapotranspiration. p 、S p It determines how much precipitation will become baseflow flow Q b dominant factor.

[0057] Based on the above BFC curve (i.e. Q b / P formula), which can achieve accurate prediction of baseflow flow in the target basin during drought period.

[0058] 105. Determine the impact of drought on baseflow changes in the target watershed based on the predicted baseflow, the second historical baseflow, and the first historical baseflow.

[0059] In this embodiment, the impact of drought on baseflow changes in the target watershed can include: the actual change in baseflow during drought periods compared to non-drought periods; the impact of baseflow inconsistency caused by long-term drought on baseflow changes in the target watershed; and the impact of changes in meteorological factors (drought index) during long-term drought on baseflow changes in the target watershed. Using this impact, we can accurately determine the impact of drought on baseflow changes in the target watershed.

[0060] In some embodiments of the present application, the actual change value of the base flow during the drought period compared to the non-drought period can be determined based on the first difference between the second historical base flow and the first historical base flow. For example, the first difference can be directly used as the actual change value of the base flow during the drought period compared to the non-drought period.

[0061] In some embodiments of the present application, the degree of impact of baseflow inconsistency caused by a long-term drought on baseflow variation in the target watershed can be determined based on a second difference between the predicted baseflow and the second historical baseflow. It can be seen that the second difference represents the difference between the actual baseflow value of the target watershed under the long-term drought climate and the predicted value, and thus the degree of impact of baseflow inconsistency caused by a long-term drought on baseflow variation in the target watershed.

[0062] In some embodiments of the present application, the degree of influence of baseflow inconsistency caused by long-term drought on baseflow changes in the target watershed can be determined based on the ratio of the second difference to the first difference. For example, the ratio of the second difference to the first difference can be directly used as the degree of influence of baseflow inconsistency caused by long-term drought on baseflow changes in the target watershed (that is, the contribution of baseflow inconsistency caused by long-term drought to baseflow changes in the target watershed).

[0063] Similarly, the degree of influence of changes in meteorological factors during a long-term drought on baseflow changes in the target watershed can be determined based on the difference between the first difference and the second difference. Specifically, the degree of influence of changes in meteorological factors during a long-term drought on baseflow changes in the target watershed can be determined based on the ratio of the difference between the first difference and the second difference relative to the first difference. For example, this ratio can be directly used as the degree of influence of changes in meteorological factors during a long-term drought on baseflow changes in the target watershed (i.e., the contribution of changes in meteorological factors during a long-term drought to baseflow changes in the target watershed).

[0064] It can be seen that the actual change in baseflow during the drought period compared with the non-drought period is affected by the inconsistency of baseflow abortion caused by long-term drought and the changes in meteorological elements during the long-term drought.

[0065] In some embodiments of the present application, a time trend method may be used to attribute the factors affecting the difference in baseflow flow in the target basin during the drought period relative to the non-drought period, so as to quantify the contribution of baseflow abortion inconsistency caused by long-term drought to baseflow changes in the target basin, and the contribution of changes in meteorological elements during long-term drought to baseflow changes in the target basin. During long-term droughts, changes in baseflow are caused by both meteorological changes (such as changes in meteorological elements during long-term droughts) and basin inconsistency (such as baseflow abortion inconsistency caused by long-term droughts). If multi-year droughts have no effect on the consistency of the target basin, the attribution method may assume that the baseflow index (BFC=Q b / P) will still follow the same BFC curve as in normal times. Therefore, the inconsistency in basin characteristics only comes from the long-term drought.

[0066] like Figure 2 As shown, the BFC curve is shown, and the horizontal axis is the drought index (Ep / P), the vertical axis is the base flow index (Q b / P). Q1 is the first historical base flow of the target basin in the normal period, and P1 is the first historical precipitation of the target basin in the normal period. Q2 is the second historical base flow of the target basin in the drought period, and P2 is the second historical precipitation of the target basin in the drought period. Figure 2 As shown in the figure, the contribution of baseflow inconsistency caused by long-term drought to baseflow changes in the target basin can be calculated as:

[0067] Where ΔQ ns It refers to the magnitude of baseflow change caused by baseflow inconsistency due to long-term drought (i.e., the second difference between the predicted baseflow and the second historical baseflow). The impact of changes in meteorological factors during long-term drought on baseflow changes in the target basin can be calculated by subtracting the baseflow change caused by long-term drought from the observed actual baseflow change:

[0068] Where ΔQ c It refers to the magnitude of base flow change caused by changes in meteorological factors during a long-term drought (that is, the difference between the first difference and the second difference). ns and / or ΔQ c It can be positive or negative. ΔQ is the observed change in actual baseflow (i.e., the actual change in baseflow during the drought period compared to the non-drought period), and is calculated as:

[0069] The BFC curve is combined with the time trend method to quantify the contribution of baseflow abortion inconsistency caused by long-term drought to baseflow changes in the target basin, and the contribution of changes in meteorological factors during long-term drought to baseflow changes in the target basin. The quantitative results are as follows: Figure 3 shown. Figure 3 The contribution of baseflow inconsistency caused by long-term drought (i.e., inconsistency caused by multi-year drought) to baseflow changes in the target basins is shown for 136 target basins. Figure 3 The contribution of changes in meteorological factors (i.e., drought index) during long-term drought to changes in baseflow in the target basins is also shown for 136 target basins. Figure 3It can be seen that across the 136 target basins, the contribution of inconsistency caused by multi-year drought to baseflow variation reached an average of 36%. Meanwhile, the contribution of changes in meteorological factors (drought index) to baseflow variation reached an average of 64%. This indicates that the combined influence of these two factors leads to changes in observed baseflow values.

[0070] The BFC curve is compared with other methods to simulate the base flow. The comparison results are as follows: Figure 4 shown. Figure 4 This is a diagram showing the frequency cumulative distribution of the simulation effects of different simulation methods for predicting base flow on multiple target watersheds. The simulation effect can be reflected by the Nash-Sutcliffe efficiency coefficient (NSE). Figure 4 It can be seen that the BFC curve simulates baseflow better than other methods, and the BFC curve has the largest number of target watersheds with NSE>0, indicating that the BFC curve has superiority in simulating baseflow.

[0071] In an embodiment of the present application, after determining the impact of drought on baseflow changes in a target watershed, the method may further include: modifying design parameters of a water resource system in the target watershed based on the impact of drought on baseflow changes in the target watershed, thereby making the design of the water resource system more reasonable. The design parameters of the water resource system can be set based on actual needs, and the modification strategy for the design parameters can also be set based on actual needs, which is not limited here.

[0072] In the technical solution disclosed in this embodiment, by determining a physical formula for base flow, which includes an effective water storage capacity parameter and an evaporation efficiency parameter, the physical formula for base flow is used to accurately quantify the impact of drought on base flow changes, providing effective data support for the rational planning and design of water resource systems.

[0073] In order to better implement the method for determining the degree of influence of drought on baseflow changes in the embodiment of the present application, based on the method for determining the degree of influence of drought on baseflow changes, the embodiment of the present application further provides a device for determining the degree of influence of drought on baseflow changes. The device for determining the degree of influence of drought on baseflow changes may include: A first acquisition module is used to acquire first historical hydrological data of the target watershed during a non-drought period, wherein the first historical hydrological data includes a first historical base flow, a first historical precipitation, and a first historical potential evaporation; a first determination module, configured to determine a physical formula for base flow, wherein the physical formula includes an effective water storage capacity parameter and an evaporation efficiency parameter, wherein the effective water storage capacity parameter and the evaporation efficiency parameter are calibrated using first historical hydrological data; A second acquisition module is used to obtain second historical hydrological data of the target watershed during the drought period, wherein the second historical hydrological data includes a second historical base flow, a second historical precipitation, and a second historical potential evaporation; A second determination module is used to determine the predicted base flow corresponding to the second historical precipitation and the second historical potential evaporation using a physical formula; The third determination module is used to determine the impact of drought on the base flow change in the target watershed based on the predicted base flow, the second historical base flow and the first historical base flow.

[0074] The present application also provides a computer device that integrates any one of the devices for determining the degree of influence of drought on base flow change provided in the present application. Figure 5 , which shows a schematic diagram of the structure of the computer device involved in the embodiment of the present application, specifically: The computer device may include one or more processing core processors 501, one or more computer readable storage media memories 502, a power supply 503, an input unit 504 and other components. Those skilled in the art will understand that Figure 5 The computer device structure shown in the figure is not intended to limit the computer device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange components differently. Processor 501 is the control center of the computer device. It connects the various components of the entire computer device using various interfaces and lines. By running or executing software programs and / or modules stored in memory 502 and accessing data stored in memory 502, it performs various functions of the computer device and processes data, thereby providing overall monitoring of the computer device. Optionally, processor 501 may include one or more processing cores; preferably, processor 501 may integrate an application processor and a modem processor, wherein the application processor primarily processes the operating system, user interface, and application programs, while the modem processor primarily handles wireless communications. It is understood that the modem processor may not be integrated into processor 501.

[0075] Memory 502 can be used to store software programs and modules. Processor 501 executes various functional applications and data processing by running the software programs and modules stored in memory 502. Memory 502 may primarily include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function (such as sound playback or image playback); the data storage area may store data generated based on the use of the computer device. Furthermore, memory 502 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device. Accordingly, memory 502 may also include a memory controller to provide processor 501 with access to memory 502.

[0076] The computer device also includes a power supply 503 for supplying power to various components. Preferably, the power supply 503 can be logically connected to the processor 501 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The power supply 503 can also include one or more DC or AC power supplies, a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator, and other arbitrary components.

[0077] The computer device may further include an input unit 504 , which may be configured to receive input digital or character information and generate keyboard, mouse, joystick, optical or trackball signal input related to user settings and function control.

[0078] Although not shown, the computer device may further include a display unit, etc., which will not be described in detail here. Specifically, in this embodiment, the processor 501 in the computer device will load the executable files corresponding to one or more application processes into the memory 502 according to the following instructions, and the processor 501 will run the application stored in the memory 502 to implement various functions, such as: Obtain first historical hydrological data of the target watershed during a non-drought period, wherein the first historical hydrological data includes a first historical baseflow, a first historical precipitation, and a first historical potential evaporation; determine a physical formula for baseflow, wherein the physical formula includes an effective water storage capacity parameter and an evaporation efficiency parameter, and the effective water storage capacity parameter and the evaporation efficiency parameter are calibrated using the first historical hydrological data; obtain second historical hydrological data of the target watershed during a drought period, wherein the second historical hydrological data includes a second historical baseflow, a second historical precipitation, and a second historical potential evaporation; determine a predicted baseflow corresponding to the second historical precipitation and the second historical potential evaporation using the physical formula; and determine the degree of influence of drought on baseflow changes in the target watershed based on the predicted baseflow, the second historical baseflow, and the first historical baseflow.

[0079] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be accomplished by instructions, or by controlling related hardware through instructions. The instructions may be stored in a computer-readable storage medium and loaded and executed by a processor.

[0080] To this end, embodiments of the present application provide a computer-readable storage medium, which may include a read-only memory (ROM), random access memory (RAM), a disk, or an optical disk. A computer program is stored thereon, and the computer program is loaded by a processor to execute the steps of any of the methods for determining the impact of drought on baseflow variation provided in embodiments of the present application. For example, the computer program, when loaded by the processor, may execute the following steps: Obtain the first historical hydrological data of the target basin during the non-drought period, the first historical hydrological data including the first historical baseflow, the first historical precipitation and the first historical potential evaporation; determine the physical formula for the baseflow, the physical formula including the effective water storage capacity parameter and the evaporation efficiency parameter, and the effective water storage capacity parameter and the evaporation efficiency parameter are calibrated using the first historical hydrological data; obtain the second historical hydrological data of the target basin during the drought period, the second historical hydrological data including the second historical baseflow, the second historical precipitation and the second historical potential evaporation; determine the predicted baseflow corresponding to the second historical precipitation and the second historical potential evaporation using the physical formula; and determine the impact of drought on baseflow changes in the target basin based on the predicted baseflow, the second historical baseflow and the first historical baseflow.

[0081] Furthermore, embodiments of the present application provide a computer program product or computer program, comprising computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to implement the method for determining the impact of drought on baseflow variation as described in any one of the above items.

[0082] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the detailed description of other embodiments above and will not be repeated here.

[0083] The specific implementation of the above operations can be found in the previous embodiments and will not be repeated here.

[0084] The above is a detailed introduction to the method, equipment and medium for determining the impact of drought on base flow changes provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core ideas. At the same time, for technical personnel in this field, based on the ideas of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for determining the impact of drought on base flow change, characterized in that: The method for determining the impact of drought on base flow change includes: Acquiring first historical hydrological data of the target watershed during a non-drought period, wherein the first historical hydrological data includes a first historical base flow, a first historical precipitation, and a first historical potential evaporation; Determining a physical formula for base flow, wherein the physical formula includes an effective water storage capacity parameter and an evaporation efficiency parameter, and the effective water storage capacity parameter and the evaporation efficiency parameter are calibrated using the first historical hydrological data; Acquiring second historical hydrological data of the target watershed during a drought period, wherein the second historical hydrological data includes a second historical base flow, a second historical precipitation, and a second historical potential evaporation; Determine the predicted base flow corresponding to the second historical precipitation and the second historical potential evaporation using the physical formula; The impact of drought on baseflow changes in the target watershed is determined based on the predicted baseflow, the second historical baseflow, and the first historical baseflow.

2. The method for determining the impact of drought on base flow change according to claim 1, characterized in that: The impact of drought on the base flow change in the target watershed includes: the actual change in base flow during the drought period compared with the non-drought period, the impact of base flow inconsistency caused by long-term drought on the base flow change in the target watershed, and the impact of changes in meteorological elements during long-term drought on the base flow change in the target watershed.

3. The method for determining the impact of drought on base flow change according to claim 2, wherein: an actual change in base flow during the drought period compared to the non-drought period, determined based on a first difference between the second historical base flow and the first historical base flow; The influence degree of baseflow abortion inconsistency caused by long-term drought on baseflow change in the target watershed is determined based on a second difference between the predicted baseflow and the second historical baseflow; The degree of influence of changes in meteorological elements during a long-term drought on changes in base flow in the target watershed is determined based on a difference between the first difference and the second difference.

4. The method for determining the impact of drought on base flow change according to claim 3, wherein: The influence of baseflow inconsistency caused by long-term drought on baseflow changes in the target watershed is determined according to the ratio of the second difference to the first difference.

5. The method for determining the impact of drought on base flow change according to claim 1, wherein: Before obtaining the first historical hydrological data of the target basin in the non-drought period, the method further includes: In the preset watersheds, the target watershed having a drought period with a duration greater than a preset length is determined.

6. The method for determining the impact of drought on base flow change according to claim 1, wherein: Determining the predicted base flow corresponding to the second historical precipitation and the second historical potential evaporation using the physical formula includes: Using the second historical precipitation as the precipitation in the physical formula, and using the second historical potential evaporation as the potential evaporation in the physical formula, to determine a value of base flow in the physical formula; The value of the base flow in the physical formula is used as the value of the predicted base flow corresponding to the second historical precipitation and the second historical potential evaporation.

7. The method for determining the impact of drought on base flow change according to claim 6, characterized in that: The physical formula includes the relationship between the drought index, the basin retention index, the base flow index and the evaporation efficiency parameter, wherein the drought index includes the ratio between potential evaporation and precipitation, the basin retention index includes the ratio between the effective water storage capacity parameter and precipitation, and the base flow index includes the ratio between base flow and precipitation.

8. The method for determining the impact of drought on base flow change according to claim 7, wherein: The physical formulas include the following formulas: Among them, Q b is the base flow, P is the precipitation, S p is the effective water storage capacity parameter, E p is the potential evaporation capacity, and α is the evaporation efficiency parameter.

9. A computer device, characterized in that: The computer device comprises: one or more processors; Memory; and One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the processor to implement the steps in the method for determining the impact of drought on base flow change according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that A computer program is stored thereon, and the computer program is loaded by a processor to execute the steps of the method for determining the degree of influence of drought on base flow change according to any one of claims 1 to 8.

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