Method and apparatus for quantitatively attributing runoff change trend considering snowmelt effect

Abstract

The application provides a runoff change trend quantitative attribution method considering the influence of snowmelt, comprising: obtaining specific global hydrological data, the specific global hydrological data comprising runoff of global observation hydrological sites, global rainfall, snowmelt and potential evapotranspiration; based on the specific global hydrological data, evaluating target change trends of rainfall and runoff, potential evapotranspiration and runoff, and snowmelt and runoff, and testing whether all target change trends are significant when the change significance is at a specific threshold; if all target change trends are significant, establishing a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis; and based on the Budyko hydrothermal coupling equation, extending the Budyko framework to runoff change trend evaluation, and establishing a runoff change trend quantitative attribution framework. In a relatively simple way, the action mechanism of various environmental factors on the runoff change trend is comprehensively discussed, and the runoff change trend quantitative attribution of different latitude zones in the world is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrology and water resources, and particularly relates to a runoff change trend quantitative attribution method considering the influence of snowmelt. BACKGROUND

[0002] The change trend of land hydrological cycle and its mechanism under the changing environment is a hot issue in the research of hydrology and water resources. Under the background of global warming, the hydrological cycle system is continuously changing, and runoff, as a key link of the land hydrological cycle, is also rapidly changing. Quantitative evaluation of the influence of changing environment on long-term change trend of runoff is of great significance for understanding the historical runoff change rule and predicting future water resources. Many scholars have evaluated the influencing factors of runoff change trend by comprehensively analyzing the temporal and spatial change trend of runoff in different regions. However, the runoff change in different regions is influenced by the comprehensive effect of local environmental factors, and the runoff data sources and research methods of regional scale research are different, which may lead to deviation of the research results. Snowmelt is the main part of the cryosphere, and in high latitude / high altitude areas, snowmelt is the main source of local runoff and has important significance for regional water cycle. By combining the Budyko water-heat coupling balance equation and the runoff trend test method, a runoff change trend attribution model considering snowmelt is constructed, so as to comprehensively explore the mechanism of the influence of each environmental factor on the runoff change trend in a simple way, and realize the quantitative attribution of runoff change trend in different latitude zones in the world.

[0003] In summary, how to effectively and conveniently consider the influence of snowmelt on the change trend of runoff, and establish a simple model, is still a problem to be solved by those skilled in the art. SUMMARY

[0004] The present application provides a runoff change trend quantitative attribution method considering the influence of snowmelt, which solves the problem that there is no effective and convenient method to consider the influence of snowmelt on the change trend of runoff in the prior art, and no simple model is established.

[0005] The present application provides a runoff change trend quantitative attribution method considering the influence of snowmelt, which solves the problem that there is no effective and convenient method to consider the influence of snowmelt on the change trend of runoff in the prior art, and no simple model is established.

[0006] Obtaining specific global hydrological data, the specific global hydrological data including runoff data, global rainfall data, snowmelt data and potential evapotranspiration data of global observation hydrological stations;

[0007] Based on the specific global hydrological data, evaluating the target change trends of rainfall and runoff, potential evapotranspiration and runoff, and snowmelt and runoff, and testing whether all target change trends are significant when the change significance is in a specific threshold;

[0008] If all target trends are significant, a Budyko hydrothermal coupling equation considering snowmelt is established based on the Budyko hypothesis;

[0009] Based on the Budyko hydrothermal coupling equation, the Budyko framework is extended to the runoff trend evaluation, and a runoff trend quantitative attribution framework is established.

[0010] According to the method, the specific global hydrological data is obtained, and the specific global hydrological data includes runoff data, global precipitation data, snowmelt data and potential evapotranspiration data of global observation hydrological sites, and specifically includes:

[0011] The runoff data of the global observation hydrological sites in the GSIM data set is searched and downloaded;

[0012] The precipitation data, snowmelt data and potential evapotranspiration data of the global road surface data assimilation system are searched and downloaded.

[0013] According to the method, the target trends of precipitation and runoff, potential evapotranspiration and runoff, and snowmelt and runoff are evaluated based on the specific global hydrological data, and specifically include:

[0014] Based on the specific global hydrological data, the Mann-Kendall trend test method and Sen's slope estimation method are used to evaluate the target trends of precipitation and runoff, potential evapotranspiration and runoff, and snowmelt and runoff.

[0015] According to the method, the change significance is at a specific threshold, and specifically includes:

[0016] The change significance level α is 0.1.

[0017] According to the method, the Budyko hydrothermal coupling equation considering snowmelt is established based on the Budyko hypothesis, and specifically includes:

[0018] The Budyko hydrothermal coupling balance equation considering the snowmelt element is represented by the following formula:

[0019]

[0020] Wherein, is the snowmelt amount, P and PET represent the precipitation and potential evapotranspiration in the basin respectively; n is the basin underlying surface parameter, and R is the basin water quantity.

[0021] According to the method, the derivation process of the Budyko water-heat coupling balance equation considering the snowmelt element is specifically as follows:

[0022] The water-heat coupling balance equation of the basin is determined by the following formula:

[0023]

[0024] In the formula, P, ET and PET respectively represent the precipitation, evaporation and potential evaporation in the basin; and n is a parameter of the underlying surface of the basin.

[0025] The water balance equation of the basin is determined by the following formula:

[0026]

[0027] In the formula, R is the water quantity of the basin.

[0028] Finally, the snowmelt amount is replaced by the precipitation P to obtain the Budyko water-heat coupling balance equation considering the snowmelt element:

[0029]

[0030] In the formula, Q is the runoff of the basin; and is the snowmelt amount.

[0031] Further, the total differential decomposition of the runoff change considering the snowmelt is derived by the following formula:

[0032] ,

[0033] In the formula, Q is the runoff of the basin; and .

[0034] According to the method, the Budyko framework is extended to the runoff change trend evaluation based on the Budyko water-heat coupling equation, and a quantitative attribution framework of the runoff change trend is established, and specifically includes the following steps.

[0035] The average precipitation P, evaporation ET, potential evaporation PET and snowmelt amount snowmelt are taken as input variables, the underlying surface parameter n of every five years is calculated, so that the runoff trend evaluation equation is represented by the following formula:

[0036]

[0037] In the formula, Q is the runoff of the basin; and represents the influence amount of the factor on the runoff change. representing any element in the factor set {underlying surface parameter n, snowmelt amount snowmelt , potential evapotranspiration PET, rainfall P}, is the average value of the factor , represents the change amount of the factor relative to the baseline period;

[0038]

[0039] wherein, represents the influence amount of each factor on the runoff change trend;

[0040]

[0041] In the formula,

[0042] , , and are the influence amounts of rainfall P, potential evapotranspiration PET, snowmelt amount snowmelt and underlying surface parameter n change on the runoff change trend.

[0043] The present application also provides a device for quantitatively attributing runoff change trend considering the influence of snowmelt, comprising:

[0044] an acquisition unit configured to acquire specific global hydrological data, the specific global hydrological data comprising runoff data of global observation hydrological sites, global rainfall data, snowmelt data and potential evapotranspiration data;

[0045] a verification unit configured to evaluate target change trends of rainfall and runoff, potential evapotranspiration and runoff, and snowmelt and runoff based on the specific global hydrological data, and verify whether all target change trends are significant when the change significance is at a specific threshold;

[0046] a building unit configured to build a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis if all target change trends are significant;

[0047] an extending unit configured to extend the Budyko framework to runoff change trend evaluation based on the Budyko hydrothermal coupling equation, and build a runoff change trend quantitative attribution framework.

[0048] The present application also provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for quantitatively attributing runoff change trend considering the influence of snowmelt according to any one of the above embodiments when executing the program.

[0049] The application further provides a non-transitory computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the method for quantitatively attributing runoff change trend considering the influence of snowmelt according to any of the above.

[0050] The application provides a method for quantitatively attributing runoff change trend considering the influence of snowmelt, which comprises the following steps: obtaining specific global hydrological data, wherein the specific global hydrological data comprises runoff data of global observation hydrological sites, global rainfall data, snowmelt data and potential evapotranspiration data; based on the specific global hydrological data, evaluating target change trends of rainfall and runoff, potential evapotranspiration and runoff, and snowmelt and runoff, and verifying whether all the target change trends are significant when the change significance is at a specific threshold; if all the target change trends are significant, establishing a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis; and extending the Budyko framework to runoff change trend evaluation based on the Budyko hydrothermal coupling equation, and establishing a runoff change trend quantitative attribution framework. The method provided by the application can comprehensively explore the action mechanism of various environmental factors on runoff change trend in a simple way by constructing a runoff change trend attribution model considering snowmelt, and realizes quantitative attribution of runoff change trend in different latitude zones around the world. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the present application or prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0052] Figure 1 The flowchart of the method for quantitatively attributing runoff change trend considering the influence of snowmelt provided by the application is shown in the figure.

[0053] Figure 2 The structural diagram of the device for quantitatively attributing runoff change trend considering the influence of snowmelt provided by the application is shown in the figure.

[0054] Figure 3 The flowchart of another method for quantitatively attributing runoff change trend considering the influence of snowmelt provided by the application is shown in the figure.

[0055] Figure 4 The structural diagram of another device for quantitatively attributing runoff change trend considering the influence of snowmelt provided by the application is shown in the figure.

[0056] Figure 5 The structural diagram of the electronic device provided by the application is shown in the figure. DETAILED DESCRIPTION

[0057] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0058] There is no effective and convenient solution to consider the influence of snowmelt on the runoff change trend in the prior art, and there is no method to establish a simple model. In the following, the method for quantitatively attributing the runoff change trend considering the influence of snowmelt will be described in conjunction with Figure 1 The method for quantitatively attributing the runoff change trend considering the influence of snowmelt provided by the present application. Figure 1 The flowchart of the method for quantitatively attributing the runoff change trend considering the influence of snowmelt provided by the present application is shown in Figure 1 The method comprises the following steps.

[0059] In step 110, specific global hydrological data is obtained, wherein the specific global hydrological data comprises runoff data, global rainfall data, snowmelt data and potential evapotranspiration data of global observation hydrological sites.

[0060] Specifically, the specific global hydrological data is obtained, which usually comprises runoff data, global rainfall data, snowmelt data and potential evapotranspiration data obtained from global observation hydrological sites.

[0061] In step 120, target change trends of rainfall and runoff, potential evapotranspiration and runoff, and snowmelt and runoff are evaluated based on the specific global hydrological data, and whether all the target change trends are significant when the change significance is at a specific threshold is verified.

[0062] Specifically, based on the obtained specific global hydrological data, target change trends of rainfall and runoff, target change trends of potential evapotranspiration and runoff, and target change trends of snowmelt and runoff are evaluated, and whether each target change trend is significant when the change significance is at a specific threshold is verified.

[0063] In step 130, if all the target change trends are verified to be significant, a Budyko hydrothermal coupling equation considering snowmelt is established based on the Budyko hypothesis.

[0064] Specifically, if all the target change trends are verified to be significant, a Budyko hydrothermal coupling equation considering the snowmelt factor is established based on the Budyko hypothesis.

[0065] In step 140, the Budyko framework is extended to runoff change trend evaluation based on the Budyko hydrothermal coupling equation, and a runoff change trend quantitative attribution framework is established.

[0066] Specifically, based on the Budyko hydrothermal coupling equation considering the snowmelt factor, the Budyko framework is extended to runoff change trend evaluation to establish a runoff change trend quantitative attribution framework.

[0067] The method provided by the embodiment of the present application comprises the following steps: obtaining specific global hydrological data, wherein the specific global hydrological data comprises runoff data of global observation hydrological sites, global rainfall data, snowmelt data and potential evapotranspiration data; evaluating target change trends of rainfall and runoff, potential evapotranspiration and runoff, and snowmelt and runoff based on the specific global hydrological data, and checking whether all the target change trends are significant when the change significance is in a specific threshold; if all the target change trends are significant, establishing a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis; and extending the Budyko framework to runoff change trend evaluation based on the Budyko hydrothermal coupling equation to establish a runoff change trend quantitative attribution framework. The method provided by the present application can comprehensively explore the action mechanism of various environmental factors on the runoff change trend in a relatively simple way by constructing a runoff change trend attribution model considering snowmelt, and realizes quantitative attribution of runoff change trends in different latitude zones in the world.

[0068] Based on the above embodiment, in the method, the specific global hydrological data comprises runoff data of global observation hydrological sites, global rainfall data, snowmelt data and potential evapotranspiration data, and specifically comprises:

[0069] searching and downloading runoff data of global observation hydrological sites in the GSIM dataset;

[0070] searching and downloading rainfall data, snowmelt data and potential evapotranspiration data of the global land surface data assimilation system.

[0071] Specifically, the collection of observation data: global observation runoff data from the GSIM dataset is collected. Specifically, the runoff data of 30959 global hydrological sites is compiled, and to improve the spatial coverage of runoff data in China, the runoff data of 372 hydrological sites in China is also fused. The period of 1958-2015 is selected as the research period, the observation year is greater than 25 years, and the site has at least 25 years of daily runoff data greater than 335 days, which meets the long-term water balance formula.

[0072] Collection of simulation data: rainfall data and snowmelt data are manually downloaded and processed, which are derived from the global land surface data assimilation system (GLDAS-2.0) with a spatial resolution of 0.25° and a time coverage length of 1948-2014. The potential evapotranspiration data is derived from the Meteorological Research Unit of the University of East Anglia, UK, with a spatial resolution of 0.5° and a time coverage length of 1901-2019.

[0073] Based on the above embodiments, the method of assessing the target changing trends of rainfall and runoff, potential evapotranspiration and runoff, and snowmelt and runoff based on the specific global hydrological data specifically includes:

[0074] Based on the specific global hydrological data, the target trends of rainfall and runoff, potential evapotranspiration and runoff, and snowmelt and runoff were assessed using the Mann-Kendall trend test and Sen's slope estimation method.

[0075] Specifically, runoff change trend test: The Mann-Kendall trend test and Sen's slope estimation method were used to assess the change trends (increase / decrease) of rainfall, potential evapotranspiration, snowmelt and runoff, and to test whether the changes were significant at the significance level of α=0.1.

[0076] Based on the above embodiments, in this method, the significance of the change being at a specific threshold specifically includes:

[0077] The significance level of the change was α = 0.1.

[0078] Specifically, the preferred significance level for the change is α = 0.1.

[0079] Based on the above embodiments, the method of establishing the Budyko hydrothermal coupling equation considering snow melting based on the Budyko assumption specifically includes:

[0080] The Budyko hydrothermal coupling equilibrium equation considering snowmelt factors is expressed by the following formula:

[0081]

[0082] in, P represents snowmelt, and PET represents precipitation and potential evapotranspiration within the watershed, respectively; n represents the underlying surface parameter of the watershed, and R represents the watershed water volume.

[0083] Specifically, the Budyko hydrothermal coupling equation: The Budyko assumption describes the long-term evapotranspiration of the watershed ( ET ) and water (basin precipitation) P ) and energy (potential evapotranspiration of the basin) PET The relationship between snowmelt (and other natural phenomena) in mid- to high-latitude regions. snowmelt Snowmelt is one of the sources of runoff replenishment, and changes in snowmelt can have a significant impact on local runoff trends. Therefore, in this embodiment of the invention, snowmelt amount is incorporated into the Budyko hydrothermal coupling equilibrium equation.

[0084] Based on the above embodiments, the derivation process of the Budyko hydrothermal coupling equilibrium equation considering snow melting factors in this method specifically includes:

[0085] The water and heat coupling balance equation of the basin is determined by the following formula:

[0086]

[0087] In the formula, P, ET and PET respectively represent the precipitation, evaporation and potential evaporation in the basin; n is the underlying surface parameter of the basin;

[0088] The water balance equation of the basin is determined by the following formula:

[0089]

[0090] In the formula, R is the water quantity of the basin;

[0091] Finally, the snowmelt quantity is replaced by the rainfall P in the above formula, and the Budyko water and heat coupling balance equation considering the snowmelt element is obtained:

[0092]

[0093] In the formula, is the snowmelt quantity;

[0094] Further, the total differential decomposition of the runoff change considering the snowmelt is derived by the following formula:

[0095] ,

[0096] In the formula, .

[0097] Specifically, the water and heat coupling balance equation of the basin is:

[0098]

[0099] In the formula, P and PET respectively represent the precipitation and potential evaporation in the basin; n n is the underlying surface parameter of the basin, representing all other factors affecting the distribution of precipitation quantity except for the precipitation and potential evaporation, including soil properties, vegetation characteristics and land use change, etc., and the underlying surface parameter n of the basin n can be calculated by the least mean square error.

[0100] Further, in a closed basin, the water balance equation of the basin can be expressed as P = ET + R + ∆S（1） In the formula, AS is the land water storage change of the basin. For a long-term time scale, the land water storage change is approximately 0 and can be generally ignored. In combination with equation (1), the following can be obtained:

[0101] .

[0102] Further, in the middle and high latitude areas, snowmelt ( snowmelt ) is one of the runoff sources, and the change of snowmelt will have an important influence on the local runoff change trend. Existing research shows that if the influence of snowmelt change is not considered, the runoff simulation in high latitude areas will have obvious deviation. Therefore, the snowmelt element is integrated into the Budyko water-heat coupling balance equation in the embodiment of the application:

[0103] .

[0104] Based on the above embodiment, in the method, the Budyko water-heat coupling equation is used to extend the Budyko framework to runoff change trend evaluation, and a runoff change trend quantitative attribution framework is established, and specifically includes:

[0105] The average rainfall P, evaporation ET, potential evapotranspiration PET and snowmelt amount snowmelt of every five years are taken as input variables, and the underlying surface parameter n of every five years is calculated to make it meet the water-heat coupling balance method of the basin, so that the runoff trend evaluation equation is expressed by the following formula:

[0106]

[0107] Among them, represents the influence of factor on the runoff change, represents any element in the factor set {underlying surface parameter n, snowmelt amount snowmelt , potential evapotranspiration PET, rainfall P}, is the average value of factor , and represents the change amount of factor relative to the baseline period;

[0108]

[0109] Among them, represents the influence of each factor on the runoff change trend;

[0110]

[0111] In the formula,

[0112] , , and are the influence amounts of rainfall P, potential evapotranspiration PET, snowmelt amount snowmelt and underlying surface parameter n change on the runoff change trend.

[0113] Specifically, since the Budyko hypothesis needs to meet the stable basin state, the current research on runoff change attribution using the Budyko hypothesis is mostly based on a long time scale. Preferably, the research studies the causes of runoff change in two time periods (the latter stage relative to the former stage). To extend the Budyko framework to the runoff change trend evaluation, the present application selects non-continuous 5-year averages as the time window (i.e., 1958-1962, 1963-1967, …, 2008-2012, a total of 11 time windows). The P, ET, PET, and snowmelt averaged every 5 years are taken as input variables, and the underlying surface parameter n in each 5-year period is calculated to meet the water-heat coupled balance equation of the basin, and the above equation is realized by a function written by R language.

[0114] The beneficial effects brought by the embodiments of the present application are as follows:

[0115] 1. Since the required rainfall and snowmelt data are easy to obtain, and the attribution method of the present application is simple and effective, the operation cost is greatly reduced;

[0116] 2. The influence of snowmelt on the key variable of global runoff is clearly and independently analyzed;

[0117] 3. The runoff change trend quantitative attribution framework considering snowmelt can effectively improve the simulation effect of runoff change trend in middle and high latitude regions.

[0118] The runoff change trend quantitative attribution device considering the influence of snowmelt provided by the present application is described below, and the runoff change trend quantitative attribution device considering the influence of snowmelt described below can be correspondingly referred to the runoff change trend quantitative attribution method considering the influence of snowmelt described above.

[0119] Figure 2 The structure diagram of the runoff change trend quantitative attribution device considering the influence of snowmelt provided by the present application is shown as Figure 2 The device comprises an acquisition unit 210, a verification unit 220, an establishment unit 230, and an extension unit 240, wherein,

[0120] The acquisition unit 210 is configured to acquire specific global hydrological data, wherein the specific global hydrological data comprises runoff data, global rainfall data, snowmelt data, and potential evapotranspiration data of global observation hydrological sites;

[0121] The verification unit 220 is configured to evaluate target change trends of rainfall and runoff, potential evapotranspiration and runoff, and snowmelt and runoff based on the specific global hydrological data, and verify whether all target change trends are significant when the change significance is at a specific threshold.

[0122] The establishing unit 230 is configured to, if all the target change trends are significant, establish a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis;

[0123] The extending unit 240 is configured to extend the Budyko framework to runoff change trend evaluation based on the Budyko hydrothermal coupling equation, and establish a runoff change trend quantitative attribution framework.

[0124] The device for quantitatively attributing runoff change trend considering the influence of snowmelt provided by the application comprises: an obtaining unit, configured to obtain specific global hydrological data, wherein the specific global hydrological data comprises runoff data of global observation hydrological sites, global precipitation data, snowmelt data and potential evapotranspiration data; a first evaluating unit, configured to evaluate target change trends of precipitation and runoff, potential evapotranspiration and runoff, and snowmelt and runoff based on the specific global hydrological data, and check whether all the target change trends are significant when the change significance is at a specific threshold; a second establishing unit, configured to, if all the target change trends are significant, establish a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis; and a third extending unit, configured to extend the Budyko framework to runoff change trend evaluation based on the Budyko hydrothermal coupling equation, and establish a runoff change trend quantitative attribution framework. The method provided by the application can comprehensively explore the action mechanism of various environmental factors on the runoff change trend in a relatively simple way by constructing a runoff change trend attribution model considering snowmelt, and realizes quantitative attribution of runoff change trend in different latitude zones around the world.

[0125] In the device, the obtaining unit is specifically configured to search and download the runoff data of the global observation hydrological sites in the GSIM data set.

[0126] The precipitation data, the snowmelt data and the potential evapotranspiration data of the global road surface data assimilation system are searched and downloaded.

[0127] In the device, the first evaluating unit is specifically configured to evaluate the target change trends of the precipitation and the runoff, the potential evapotranspiration and the runoff, and the snowmelt and the runoff based on the specific global hydrological data, and the evaluation specifically comprises:

[0128] The first evaluating unit is specifically configured to evaluate the target change trends of the precipitation and the runoff, the potential evapotranspiration and the runoff, and the snowmelt and the runoff based on the specific global hydrological data by using the Mann-Kendall trend test method and the Sen's slope estimation method.

[0129] In the device, the change significance is at a specific threshold, and the specific threshold specifically comprises:

[0130] The change significance level α is 0.1.

[0131] On the basis of the above-mentioned embodiment, in the device, the Budyko hydrothermal coupling equation considering snowmelt is established based on the Budyko hypothesis, and specifically includes:

[0132] The Budyko hydrothermal coupling balance equation considering the snowmelt element is represented by the following formula:

[0133]

[0134] Wherein, is the snowmelt amount, P and PET represent the precipitation and potential evapotranspiration in the basin respectively; n is the basin underlying surface parameter, and R is the basin water quantity.

[0135] On the basis of the above-mentioned embodiment, in the device, the derivation process of the Budyko hydrothermal coupling balance equation considering the snowmelt element includes:

[0136] The basin hydrothermal coupling balance equation is determined by the following formula:

[0137]

[0138] In the formula, P, ET and PET represent the precipitation, evaporation and potential evapotranspiration in the basin respectively; n is the basin underlying surface parameter;

[0139] The basin water balance equation is determined by the following formula:

[0140]

[0141] Wherein, R is the basin water quantity;

[0142] Finally, the snowmelt amount is replaced by the precipitation P to obtain the Budyko hydrothermal coupling balance equation considering the snowmelt element:

[0143]

[0144] Wherein, is the snowmelt amount;

[0145] Further, the total differential decomposition of the runoff change considering the snowmelt is derived by the following formula:

[0146] ,

[0147] Wherein, .

[0148] On the basis of the above-mentioned embodiment, in the device, the Budyko hydrothermal coupling equation is used to extend the Budyko framework to the runoff change trend evaluation, and a runoff change trend quantitative attribution framework is established, and specifically includes:

[0149] The five-year average rainfall (P), evaporation (ET), potential evapotranspiration (PET), and snowmelt are calculated. snowmelt As input variables, the underlying surface parameter n is calculated every five years to ensure it conforms to the watershed hydrothermal coupling balance method. The runoff trend assessment equation is then expressed by the following formula:

[0150]

[0151] in, Representative factor The amount of influence on runoff change The factor set represents {underlying surface parameter n, snow melt amount}. snowmelt Potential evaporation of PET, rainfall of any element in P, As a factor The average value, Representative factor The change relative to the base period;

[0152]

[0153] in, This indicates the magnitude of the influence of each factor on the trend of runoff change.

[0154]

[0155] In the formula,

[0156] , , and These are precipitation (P), potential evapotranspiration (PET), and snowmelt. snowmelt The influence of changes in underlying surface parameter n on the trend of runoff variation.

[0157] Based on the above embodiments, the present invention also provides another quantitative attribution method for runoff variation trends that considers the impact of snowmelt. Figure 3 A flowchart illustrating another quantitative attribution method for runoff variation trends considering the impact of snowmelt provided by this invention is shown below. Figure 3 As shown, the method includes the following steps:

[0158] S1. Data Collection: Global observational runoff data from the GSIM dataset were collected. Specifically, runoff data from 30,959 hydrological stations worldwide were compiled. To improve the spatial coverage of runoff data within China, runoff data from 372 hydrological stations in China were also integrated. The study period was selected from 1958 to 2015, with observation years exceeding 25 years. Each station had at least 25 years of daily runoff data exceeding 335 days, conforming to the long-term water balance formula.

[0159] S2. Data Collection for Simulation: Rainfall and snowmelt data were manually downloaded and processed from the Global Land Surface Data Assimilation System (GLDAS-2.0), with a spatial resolution of 0.25° and a time coverage of 1948–2014. Potential evapotranspiration data were obtained from the meteorological raster dataset of the Meteorological Research Centre at the University of East Anglia, UK, with a spatial resolution of 0.5° and a time coverage of 1901–2019.

[0160] S3. Runoff Change Trend Test: Using the Mann-Kendall trend test and Sen's slope estimation method, assess the changing trends (increase / decrease) of rainfall, potential evapotranspiration, snowmelt, and runoff, and test whether the changes are significant at the significance level of α=0.1.

[0161] S4, Budyko hydrothermal coupling equation: The Budyko assumption describes the long-term evapotranspiration of the watershed ( ET ) and water (basin precipitation) P ) and energy (potential evapotranspiration of the basin) PET In mid-to-high latitude regions, snowmelt is one of the sources of runoff replenishment, and changes in snowmelt have a significant impact on local runoff trends. Therefore, this embodiment of the invention incorporates snowmelt factors into the Budyko hydrothermal coupling equilibrium equation.

[0162] S5. Construction of a Quantitative Attribution Framework for Runoff Change Trends: Since the Budyko hypothesis requires a stable watershed state, current studies using the Budyko hypothesis for runoff change attribution are mostly based on long-term scales, investigating the causes of runoff changes between two time periods (the latter relative to the former). To extend the Budyko framework to runoff change trend assessment, this paper selects a non-continuous 5-year average as the time window (i.e., 1958–1962, 1963–1967, …, 2008–2012, a total of 11 time windows). Using the 5-year averages of P, ET, PET, and Snowmelt as input variables, the control parameter n for each 5-year period is calculated to conform to the watershed hydrothermal coupling equilibrium equation.

[0163] Based on the above embodiments, the present invention also provides another quantitative attribution device for runoff variation trends that considers the impact of snowmelt. Figure 4 A schematic diagram of another quantitative attribution device for runoff variation trends that considers the impact of snowmelt provided by the present invention is shown below. Figure 4 As shown, the device includes the following modules:

[0164] The data collection module L1 is used to collect global observed runoff data, as well as rainfall data, snowmelt data, and potential evapotranspiration data.

[0165] A trend test module L2 uses Mann-Kendall trend test method and Sen's slope estimation method to evaluate the change trend (increase / decrease) of rainfall, potential evapotranspiration, snowmelt and runoff, and test whether the change is significant at a change significance level of alpha=0.1.

[0166] An equation building module L3, Budyko hypothesis describes the relationship among long-term evapotranspiration (ET) of a basin, water (basin precipitation P) and energy (basin potential evapotranspiration ET0) in a middle-high latitude area, snowmelt is one of the supply sources of runoff, and the change of snowmelt has an important influence on the change trend of local runoff, therefore, the embodiment of the present application integrates the snowmelt element into the Budyko water-heat coupling balance equation. ET ) and energy (basin potential evapotranspiration P ) and energy (basin potential evapotranspiration PET ) and energy (basin potential evapotranspiration

[0167] A detection and attribution module L4, since Budyko hypothesis needs to meet the stable basin state, therefore, the current research on runoff change attribution based on Budyko hypothesis is mostly based on long time scale to study the causes of runoff change in two time periods (the latter stage relative to the former stage).

[0168] The present application builds a runoff change trend quantitative attribution framework considering snowmelt by fusing trend test method and Budyko water-heat coupling balance equation, and quantitatively evaluates the causes of runoff change trend in different latitude zones in the world, so that the global runoff change trend quantitative attribution method of Budyko hypothesis can be detected and quantified.

[0169] Figure 5 An example of an entity structure schematic diagram of an electronic device is shown in FIG. 1. Figure 5As shown, the electronic device can include a processor 510, a communications interface 520, a memory 530, and a communications bus 540, wherein the processor 510, the communications interface 520, and the memory 530 complete mutual communication through the communications bus 540. The processor 510 can invoke a logic instruction in the memory 530 to execute a runoff change trend quantitative attribution method considering the influence of snowmelt, which includes: obtaining specific global hydrological data, the specific global hydrological data including runoff data of global observation hydrological sites, global rainfall data, snowmelt data, and potential evapotranspiration data; based on the specific global hydrological data, evaluating target change trends of rainfall and runoff, potential evapotranspiration and runoff, snowmelt and runoff, and verifying whether all target change trends are significant when the change significance is at a specific threshold; if all target change trends are verified to be significant, establishing a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis; extending the Budyko framework to runoff change trend evaluation based on the Budyko hydrothermal coupling equation, and establishing a runoff change trend quantitative attribution framework.

[0170] In addition, the logic instruction in the memory 530 described above can be implemented in the form of a software function unit and sold or used as an independent product, which can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or part of the technical solutions can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0171] In another aspect, the present application also provides a computer program product, which comprises a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions which, when executed by a computer, enable the computer to perform the method for quantitatively attributing runoff change trend considering the influence of snowmelt, which comprises: obtaining specific global hydrological data, the specific global hydrological data comprising runoff data of global observation hydrological sites, global precipitation data, snowmelt data and potential evapotranspiration data; based on the specific global hydrological data, evaluating target change trends of precipitation and runoff, potential evapotranspiration and runoff, snowmelt and runoff, and verifying whether all target change trends are significant when the change significance is at a specific threshold; if all target change trends are verified to be significant, establishing a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis; extending the Budyko framework to runoff change trend evaluation based on the Budyko hydrothermal coupling equation, and establishing a runoff change trend quantitative attribution framework.

[0172] In another aspect, the present application also provides a non-transitory computer-readable storage medium, which stores a computer program, the computer program being executed by a processor to implement the method for quantitatively attributing runoff change trend considering the influence of snowmelt provided above, which comprises: obtaining specific global hydrological data, the specific global hydrological data comprising runoff data of global observation hydrological sites, global precipitation data, snowmelt data and potential evapotranspiration data; based on the specific global hydrological data, evaluating target change trends of precipitation and runoff, potential evapotranspiration and runoff, snowmelt and runoff, and verifying whether all target change trends are significant when the change significance is at a specific threshold; if all target change trends are verified to be significant, establishing a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis; extending the Budyko framework to runoff change trend evaluation based on the Budyko hydrothermal coupling equation, and establishing a runoff change trend quantitative attribution framework.

[0173] The device embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected to achieve the purpose of the present embodiment scheme according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0174] Those skilled in the art can clearly understand the technical solutions of the various embodiments from the above description of the embodiments, and the various embodiments can be implemented by means of software with the necessary general hardware platforms, and of course, can also be implemented by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part of the prior art that makes a contribution, can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0175] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for quantitatively attributing trends in runoff changes considering the effect of snowmelt, characterized in that, Comprising: obtaining specific global hydrological data, the specific global hydrological data comprising runoff data of global observed hydrological sites, global precipitation data, snowmelt data and potential evapotranspiration data; based on the specific global hydrological data, evaluating target change trends of precipitation and runoff, potential evapotranspiration and runoff, snowmelt and runoff, and testing whether all target change trends are significant when change significance is at a specific threshold; if all target change trends are significant, establishing a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis; based on the Budyko hydrothermal coupling equation, extending the Budyko framework to runoff change trend evaluation, establishing a runoff change trend quantitative attribution framework, specifically comprising: The average of the rainfall P, evaporation ET, potential evapotranspiration PET and snowmelt snowmelt As an input variable, the land surface parameter n is calculated for each five-year period so that it fits the water and heat balance of the catchment. The runoff trend assessment equation is then expressed by the following formula: wherein, representative factor the amount of influence on the change in runoff, representative factor snowmelt any element in the set of factors {underlying surface parameter n, amount of snowmelt is the average value of the factor , representative factor the amount of change with respect to the reference period; R is the water volume of the basin; wherein, represents the influence amount of each factor on the runoff change trend; wherein Trend(R) represents the total amount of influence of all factors in the factor set on runoff change trend, , , and are rainfall P, potential evapotranspiration PET, snowmelt snowmelt and the influence of the change of underlying surface parameter n on the change trend of runoff; .

2. The method for quantitatively attributing the runoff change trend considering the snowmelt effect according to claim 1, characterized in that, The specific global hydrological data obtained, the specific global hydrological data comprising runoff data of global observed hydrological sites, global precipitation data, snowmelt data and potential evapotranspiration data, specifically comprising: searching and downloading runoff data of global observed hydrological sites in the GSIM dataset; searching and downloading precipitation data, snowmelt data and potential evapotranspiration data of the global road surface data assimilation system.

3. The method for quantitatively attributing the runoff change trend considering the snowmelt effect according to claim 1, characterized in that, Based on the specific global hydrological data, evaluating target change trends of precipitation and runoff, potential evapotranspiration and runoff, snowmelt and runoff, specifically comprising: Based on the specific global hydrological data, using the Mann-Kendall trend test method and Sen's slope estimation method to evaluate target change trends of precipitation and runoff, potential evapotranspiration and runoff, snowmelt and runoff.

4. The method of quantitatively attributing trends in runoff change considering snowmelt impact according to claim 1, characterized by, The change significance is at a specific threshold, specifically comprising: the change significance level α = 0.

1.

5. The method for quantitatively attributing the runoff change trend considering the snowmelt effect according to claim 1, characterized in that, The Budyko hydrothermal coupling equation considering snowmelt is established based on the Budyko hypothesis, specifically comprising: The Budyko hydrothermal coupling balance equation considering snowmelt elements is represented by the following formula: where, is the snowmelt amount, P and PET represent the precipitation and potential evapotranspiration in the basin, respectively; n is the underlying surface parameter of the basin, and R is the water quantity of the basin.

6. The method for quantitatively attributing the runoff change trend considering the snowmelt effect according to claim 5, characterized in that, The derivation process of the Budyko hydrothermal coupling balance equation considering snowmelt elements, specifically comprising: The hydrothermal coupling balance equation of the basin is determined by the following formula: wherein P, ET and PET represent precipitation, evaporation and potential evapotranspiration in the basin respectively; n is the underlying surface parameter of the basin; The hydrothermal coupling balance equation of the basin is determined by the following formula: wherein R is the water quantity of the basin; Finally, the snowmelt amount + rainfall P instead of rainfall P into the above formula, the Budyko water and heat coupling balance equation considering the snowmelt element: wherein, is the amount of snow melt; and then deriving the runoff change total differential decomposition considering snowmelt by the following formula: ， wherein .

7. An apparatus for quantitatively attributing a runoff change trend considering a snowmelt effect, for implementing the method for quantitatively attributing a runoff change trend considering a snowmelt effect according to any one of claims 1 to 6, characterized by, Comprising: an acquisition unit configured to obtain specific global hydrological data, the specific global hydrological data comprising runoff data of global observed hydrological sites, global precipitation data, snowmelt data and potential evapotranspiration data; a testing unit configured to, based on the specific global hydrological data, evaluate target change trends of precipitation and runoff, potential evapotranspiration and runoff, snowmelt and runoff, and test whether all target change trends are significant when change significance is at a specific threshold; an establishing unit configured to, if all target change trends are significant, establish a Budyko hydrothermal coupling equation considering snowmelt based on the Budyko hypothesis; An extension unit is configured to extend the Budyko framework to runoff change trend evaluation based on the Budyko hydro-thermal coupling equation, and establish a runoff change trend quantitative attribution framework.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the steps of the runoff change trend quantitative attribution method considering the influence of snowmelt when executing the program. 9.A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the runoff change trend quantitative attribution method considering the influence of snowmelt.

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