A method and system for evaluating ecosystem service function

Abstract

The present invention discloses an ecosystem service function evaluation and driving force analysis scheme. From the three levels of supply function, regulation function and support function, four service function indicators, namely soil conservation service, water conservation service, climate regulation service and biodiversity maintenance service, are selected to comprehensively evaluate the comprehensive function of ecosystem services, analyze the spatiotemporal distribution and evolution characteristics of ecosystem service functions under the comprehensive situation, and draw on PSR and DPSR analysis models to construct a driving indicator system at a spatial grid scale from two levels of ecological status such as climate, topography and land use and ecological pressure such as social economy and ecological degradation. This changes the traditional method of excessive use of economic and social indicators and district and county comprehensive indexes in watershed ecosystem service research, and makes up for the deficiency of only conducting static research on a certain point in time in the previous analysis of driving forces of geographic spatial indicators.

Description

Technical Field

[0001] The present invention relates to the field of ecological protection technology, and in particular to an ecosystem service function evaluation method and system. Background Art

[0002] Ecosystems are resource banks on which human beings depend for survival and development. They are dynamic equilibrium systems composed of biological communities and living environments. Ecosystem service research has gradually become a key direction of regional development research, and is also a core research area for regional ecological function division, protection and restoration. However, most studies are limited to the evaluation of single ecosystem service functions, and most of them use the land use unit area value to statically evaluate the regional ecosystem service value. There are relatively few studies on the long-term dynamic tracking and evaluation of the comprehensive functions of ecosystem services in the basin.

[0003] The Three Gorges Reservoir is an important ecological barrier in the upper reaches of the Yangtze River and an important ecological protection and restoration area in the Yangtze River Basin. The changes in the ecosystem services in the Three Gorges Reservoir are even more related to the ecological security of the Yangtze River Basin. In recent years, scholars at home and abroad have conducted relevant research on the ecosystem services in the Three Gorges Reservoir. For example, based on the land use perspective under the three-life space, RS and GIS technologies are used to analyze the spatiotemporal variation characteristics of the ecosystem service value in the Three Gorges Reservoir; the spatiotemporal distribution characteristics of ecosystem services under single factors such as water conservation function and soil and water conservation in typical areas of the Three Gorges Reservoir are studied.

[0004] However, current research on the ecosystem services of the Three Gorges Reservoir area still mostly uses the land use value equivalent method for calculation. The study areas are mostly concentrated in a certain reservoir section or a typical area, and the research objects are mostly a single ecosystem. There are relatively few results on the long-term monitoring of the comprehensive functions of ecosystem services at different scales in the entire reservoir area and the analysis of the dynamic changes of driving factors at different time series. Summary of the invention

[0005] In view of the defects in the prior art, the object of the present invention is to provide an ecosystem service function evaluation method and system.

[0006] In a first aspect, the present invention provides an ecosystem service function evaluation method, comprising:

[0007] Four service function indicators are selected from the three types of ecosystem service levels: supply function, regulation function and support function; the four service function indicators include water conservation service indicator, soil conservation service indicator, climate regulation service indicator and biodiversity service indicator;

[0008] Calculate the values ​​of four service function indicators;

[0009] The comprehensive index value of ecosystem services is calculated based on the values ​​of the four service function indicators;

[0010] The comprehensive service function of the Three Gorges Reservoir area ecosystem is evaluated based on the comprehensive index value.

[0011] As a preferred implementation of the present application, after calculating the comprehensive index value of the ecosystem service, the method further includes:

[0012] The Moran index and hot-spot pattern analysis methods were used to analyze the temporal evolution characteristics of ecosystem service functions in the comprehensive case of the Three Gorges Reservoir area.

[0013] Furthermore, the method also includes analyzing the driving force of the comprehensive service function of the ecosystem to obtain the driving force analysis results, specifically:

[0014] Obtain the current land use data of the Three Gorges Reservoir area, combine the PSR and DPSIR models, and construct a driving factor index system for ecosystem service functions from the two levels of state and pressure; the driving factor index system includes multiple types of driving elements and multiple driving factors;

[0015] The geographic detector was used to detect the spatiotemporal correlation between driving factors and the comprehensive service functions of ecosystems under various types of driving factors, and the degree of spatial analysis explanation of independent variables on dependent variables was measured by the determination power q value.

[0016] As a preferred implementation of the present application, after constructing the driving force factor index system of the ecosystem service function, the method further includes:

[0017] 19 factors are selected from the 7 element types of the driving force factor index system; among them, the 19 factors include positive factors, reverse factors and moderate factors;

[0018] The positive factors, negative factors and moderation factors are tempered without any quantity.

[0019] In a second aspect, an embodiment of the present invention further provides an ecosystem service function evaluation system, including:

[0020] The indicator selection unit is used to select four service function indicators from the three types of ecosystem service levels: supply function, regulation function and support function; the four service function indicators include water conservation service indicator, soil conservation service indicator, climate regulation service indicator and biodiversity service indicator;

[0021] The calculation unit is used to calculate the values ​​of the four service function indicators and calculate the comprehensive index value of ecosystem services based on the values ​​of the four service function indicators;

[0022] An evaluation unit is used to evaluate the comprehensive service function of the Three Gorges Reservoir area ecosystem according to the comprehensive index value.

[0023] As a preferred implementation of the present application, the system further includes a driving force analysis unit for analyzing the driving force of the comprehensive service function of the ecosystem to obtain a driving force analysis result, specifically:

[0024] Obtain the current land use data of the Three Gorges Reservoir area, combine the PSR and DPSIR models, and construct a driving factor index system for ecosystem service functions from the two levels of state and pressure; the driving factor index system includes multiple types of driving elements and multiple driving factors;

[0025] The geographic detector was used to detect the spatiotemporal correlation between driving factors and the comprehensive service functions of ecosystems under various types of driving factors, and the degree of spatial analysis explanation of independent variables on dependent variables was measured by the determination power q value.

[0026] As a preferred implementation of the present application, the system further includes a preprocessing unit for:

[0027] Formula (5) is used to standardize the indicator type.

[0028]

[0029] Sr tri is the standardized value of the jth index in the analysis grid r in the tth year, X tri is the original value of the jth index in the analysis grid r in the tth year, Max(X i ) and Min(X i ) represent the maximum and minimum values ​​of the j index in all years of the study area.

[0030] Beneficial effects of the present invention:

[0031] The invention discloses a scheme for evaluating the service function and driving force analysis of the ecosystem in the Three Gorges Reservoir area. The invention studies the service function of the ecosystem from three levels: supply function, regulation function and support function. Four service function indicators, namely soil conservation service, water conservation service, climate regulation service and biodiversity maintenance service, are selected to comprehensively evaluate the comprehensive function of the ecosystem service. The spatiotemporal distribution and evolution characteristics of the ecosystem service function under the comprehensive condition are analyzed. The PSR and DPSR analysis models are used to construct a driving indicator system at a spatial grid scale from two levels: ecological status such as climate, topography and land use, and ecological pressure such as social economy and ecological degradation. The system changes the traditional method of excessive use of economic and social indicators and district and county comprehensive indexes in the study of the service of the watershed ecosystem, and makes up for the deficiency of only conducting static research on a certain time point in the previous analysis of the driving force of geographic spatial indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0033] Figure 1 A flow chart showing an ecosystem service function evaluation method provided by an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of the structure of an ecosystem service function evaluation system provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0037] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0038] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0039] As used in this specification and the appended claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0040] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0041] The inventive concept of the present invention is: using a more objective and more accurate 1km grid as the minimum evaluation unit, selecting four service function indicators such as water conservation, soil conservation, climate regulation and biodiversity maintenance from the three types of ecosystem service levels, including supply function, regulation function and support function, and calculating its comprehensive service function, using the Moran index and hot and cold spot spatial correlation analysis methods to analyze the time evolution characteristics of the ecosystem service function in the Three Gorges Reservoir area from 2000 to 2020 under single factor and comprehensive conditions; at the same time, based on the land use status data of the Three Gorges Reservoir area obtained by the project team's early tracking survey and remote sensing interpretation, using the geographic information system software platform, combined with the PSR and DPSR model theory, according to the current characteristics and spatiotemporal data characteristics of regional environmental elements and socio-economic elements in the Three Gorges Reservoir area over the past 20 years, constructing the driving factor indicator system of the ecosystem service function from the two levels of "state-pressure", and using the factor detector and interaction detector in the geographic detector to analyze the laws and mechanisms of the temporal changes and spatial heterogeneity of regional ecosystem service functions. The research results of the present invention will provide theoretical basis and data support for the rational planning of resources in the Three Gorges Reservoir area, and provide reference for regional ecological restoration and sustainable development.

[0042] Please refer to Figure 1 , a flow chart of the ecosystem service function evaluation method provided by the first embodiment of the present invention, the method comprising the following steps:

[0043] S1, select four service function indicators from the three types of ecosystem service levels: supply function, regulation function and support function.

[0044] This embodiment combines the characteristics of the Three Gorges Reservoir area and its main ecological problems, and selects indicators from three types of levels: supply function, regulation function and support function of ecosystem services, including four service function indicators such as water conservation, soil conservation, climate regulation and biodiversity.

[0045] S2, calculate the values ​​of four service function indicators.

[0046] (1) Water conservation services

[0047] The water production service capacity of the ecosystem is an important prerequisite for regional human life and production, a core element for the survival and reproduction of regional organisms, and a limiting indicator for the social and economic development of the Three Gorges Reservoir area in the Yangtze River Basin. Water conservation service is a core indicator that reflects the regional water production service supply capacity. It is mainly related to regional precipitation, evaporation, surface runoff and land cover. Water conservation service is mainly calculated using the total amount of water conservation supply. The calculation formula is as follows:

[0048] WS tr =P tr -ET tr -R tr (1)

[0049] WS tr represents the total water conservation supply in grid r in year t, P tr represents the average annual precipitation in grid r in year t, ET tr represents the precipitation evapotranspiration in grid r in year t, R tr It represents the cumulative surface runoff in grid r in year t, and the surface runoff is obtained by multiplying the precipitation and the surface runoff coefficient. In this embodiment, referring to relevant literature and combining the actual situation of the Three Gorges Reservoir area, it is determined that the surface runoff coefficients of forest land and grassland are 4.65% and 3.94% respectively, and the runoff coefficient of other land use types is 0.

[0050] (2) Soil Conservation Services

[0051] Soil conservation service reflects whether the reservoir ecosystem can reduce or avoid soil erosion caused by water erosion. This embodiment is based on the revised universal soil loss equation (RUSLE) and combined with research needs to determine the reservoir soil conservation service index calculation formula as follows:

[0052] A tr =RE tr ×SE tr ×LS×(1-CCM tr ×CM tr ) (2)

[0053]

[0054] Among them, A tr represents the soil conservation scale in grid r in year t, RE tr Represents the rainfall erosivity factor. The rainfall erosivity is calculated using monthly rainfall data. represents the rainfall in the ith month, SE tr represents soil erodibility factor, LS represents slope length and slope factor, CCMtr Represents vegetation cover and management factor, CM tr Represents the soil and water conservation measures factor.

[0055] (3) Climate Regulation Services

[0056] This embodiment reflects the regional climate regulation service by calculating carbon storage. In combination with the carbon storage calculation module in the InVEST model, based on the annual land use type data, the carbon storage of aboveground, underground, dead organic matter, and soil organic matter is comprehensively considered. The specific calculation formula is as follows:

[0057]

[0058] C tr represents the total carbon sequestration in grid r in year t, c ti1 represents the aboveground carbon density of land cover type i in year t, C ti2 represents the underground carbon density of land cover type i in year t, C ti3 represents the carbon density of dead organic matter in land cover type i in year t, C ti4 represents the soil organic carbon density of land cover type i in year t, Ar tri It represents the total area of ​​land cover type i in grid r in year t.

[0059] (4) Biodiversity maintenance services

[0060] Habitat status is an important part of regional biodiversity maintenance. The study used the Habitat Suitability model in the InVest model to measure the regional biodiversity maintenance service capacity. This module reflects regional biodiversity by analyzing the threat level of human land use or natural disasters to its biodiversity, combined with the relative sensitivity of each habitat type to each threat.

[0061] S3, calculate the comprehensive index value of ecosystem services based on the values ​​of the four service function indicators.

[0062] Specifically, the comprehensive ecosystem service index is used to reflect the comprehensive ecosystem service function of the region. In order to eliminate the dimensions of the four types of ecosystem service function indicators, the indicator types are standardized before calculating the comprehensive ecosystem service index. The processing method is as follows: Formula (5). The comprehensive regional ecosystem service index in this embodiment adopts an accumulation mode, as shown in Formula (6).

[0063]

[0064]

[0065] Sr trjis the standardized value of the jth index in the analysis grid r in the tth year, X trj is the original value of the jth index in the analysis grid r in the tth year, MAx(X j ) and Min(X j ) represent the maximum and minimum values ​​of the j index in all years of the study area.

[0066] S4. Evaluate the comprehensive service function of the ecosystem in the Three Gorges Reservoir area according to the comprehensive index value.

[0067] S5, the Moran index and hot and cold spot pattern analysis methods were used to analyze the temporal evolution characteristics of ecosystem service functions in the comprehensive case of the Three Gorges Reservoir area.

[0068] (1) Moran's I

[0069] Spatial correlation is the first law of geography. Geographical objects and attributes are interrelated in spatial distribution, that is, correlation, and similar objects are more closely related. At present, global spatial autocorrelation Moran's I is a widely used model in geostatistical spatial correlation analysis. This study analyzes the correlation of the geographical distribution of ecosystem service functions in the study area based on this model, and determines whether the index has a clustered distribution feature in the Three Gorges Reservoir area. The formula is as follows:

[0070]

[0071] Where X tr is the observation value in the r grid in year t, r and r' are two grid areas in space, w rr′ is the spatial weight matrix of the two regions, indicating the adjacency relationship between the regions, w rr′ =1, then adjacent, w rr′ = 0 means non-adjacent, and m is the total number of grids. Moran's I greater than 0 indicates that the observations in the two regions are positively correlated, and less than 0 indicates negative correlation. The larger the absolute value, the stronger the positive or negative correlation, and the smaller the absolute value, the weaker the correlation.

[0072] (2) Analysis of hot and cold spots

[0073] On the basis of analyzing the regional spatial autocorrelation, it is necessary to further study the spatial characteristics of the regional agglomeration structure, analyze the spatial correlation and agglomeration law of the ecosystem service function in the Three Gorges Reservoir area, and analyze the evolution characteristics of its spatiotemporal pattern. Hot and cold spot analysis is an effective method to study the local spatial clustering characteristics, reflecting the degree of agglomeration of high and low values ​​of observations in local space. The Getis-Ord Gi* model method is as follows:

[0074]

[0075] S6, analyze the driving force of the comprehensive service functions of the ecosystem and obtain the driving force analysis results.

[0076] Specifically, the current land use data of the Three Gorges Reservoir area were obtained, and the PSR and DPSIR models were combined to construct a driving factor index system for ecosystem service functions from the two levels of state and pressure. 19 factors were selected from the 7 element types of the driving factor index system. Among them, the 19 factors included positive factors, reverse factors and moderate factors. The positive factors, reverse factors and moderate factors were subjected to quantity-free tempering. The geographic detector was used to detect the spatiotemporal correlation between driving factors and the comprehensive service functions of ecosystems under various types of driving factors, and the degree of spatial analysis explanation of independent variables on dependent variables was measured by the determining power q value.

[0077] 1. Data Acquisition and Preprocessing

[0078] This study covers the period from 2000 to 2020, before and after the Three Gorges Reservoir is filled with water, with five years as a time node, namely 2000, 2005, 2010, 2015 and 2020; the study adopts a multi-scale spatial analysis method, with a 1km*1km grid as the minimum evaluation unit of the indicator, the district and county boundaries of the administrative division as the district and county scale analysis unit, the reservoir head, reservoir middle and reservoir tail as the district-level analysis unit, and the entire Three Gorges Reservoir as the basin-wide analysis unit. This study mainly uses Landsat TM and Landsat8OLI images of the Three Gorges Reservoir in 2000, 2005, 2010, 2015 and 2020 as the image data source for extracting regional land use changes over the years, with a spatial resolution of 30 meters. With the support of ArcGIS and Erdas software, a combination of supervised classification and manual visual interpretation is used to extract the current land use data of the reservoir area. The accuracy verification of the five-period data is higher than 83%. The terrain data mainly uses ASTER GDEM 30M product data. The image data and terrain data are all from the geospatial data cloud platform (http: / / www.gscloud.cn / ). The administrative district vector data of Chongqing section comes from the Chongqing Municipal Land and Housing Administration Bureau, and the Hubei section comes from the Geographic National Conditions Monitoring Cloud Platform (http: / / www.dsac.cn / ). Vegetation coverage is extracted based on MOD13Q1 product data, and vegetation net primary productivity is obtained based on MOD17A3 data products. Other core data include mean temperature spatial interpolation dataset, monthly precipitation dataset, monthly potential evapotranspiration dataset, soil texture dataset, socioeconomic spatial distribution kilometer grid dataset, etc. The data sources are detailed in Table 1.

[0079] Table 1. Indicator system of driving factors of ecosystem services in the Three Gorges Reservoir area

[0080] Tab.1 Index system of ecosystem service drivers in the Three GorgesReservoir Area

[0081]

[0082] 2. Driving Force Analysis

[0083] (1) Driving factors

[0084] Ecosystem service functions are continuously affected by the natural environment, social conditions, and economic development. Their status and evolution are all produced in a comprehensive environment. Therefore, the driving force of ecosystem services is complex. By analyzing existing literature, combining the actual situation of the Three Gorges Reservoir area, consulting professionals in related fields, and considering data availability, this study is based on the pressure-state-response (PSR) evaluation model proposed by the Organization for Economic Cooperation and Development (OECD) in 1990. The results of ecosystem service capacity evaluation are used as the ecosystem response layer, and the driving force of ecosystem services is selected from the two levels of ecological pressure and ecological state. 19 factors are selected from 7 factor types. The content, model, and data source of the elements and factors are shown in Table 1. There are many parameters involved in the indicator model, D r represents the topographic index in the grid number r, E and S represent the elevation and slope values ​​of any point in the geographic space, respectively. and They represent the average elevation and average slope of the study area, respectively, and m represents the number of values ​​contained in the grid. tr represents the habitat area ratio in the analysis grid r of the study area in year t, A trf , A trg , A trw are the total land cover areas of forest, grassland and water in the analysis grid r in year t, respectively. tri It represents the total area of ​​land cover type i in the analysis grid r in year t, and l represents the number of all land cover types. LUI tr represents the land use intensity in grid r in year t, IC i A represents the intensity coefficient of human impact on land cover type i, r Represents the total area of ​​the r analysis grid.

[0085] In order to eliminate the influence of factor units and types, each factor was dimensionless during the research process. According to the factor type, the normalization of the positive factor was based on formula (5), the normalization of the reverse factor was based on formula (7), and the normalization of the moderation factor was based on formula (8). In the formula, a1 and a2 represent the minimum and maximum values ​​of the optimal range of the moderation index, respectively.

[0086]

[0087]

[0088] (2) Geographic detector

[0089] This example explores the driving force of ecosystem service functions mainly from the spatiotemporal dimension, where spatial heterogeneity is a typical geographical characteristic. This example uses the geographic detector model to detect the spatiotemporal correlation between driving factors and ecosystem comprehensive service functions under various types of driving factors, and measures the degree of spatial heterogeneity of independent variables on dependent variables through the determination force q value, as shown in the following formula (9).

[0090]

[0091] q represents the explanatory power of the driving factor on the spatial differentiation of ecosystem service functions, with a range of [0,1], and the larger the value, the greater the explanatory power; L (h = 1, 2, ...) represents the number of classifications or partitions of the variable; N h and N are the number of units in layer h and the whole study area, respectively; and σ 2 are the variances of the comprehensive index of ecosystem service function of layer h and the whole study area, respectively.

[0092] The interaction detector in the geographic detector model is used to identify the interactions between various driving factors, and to evaluate whether the explanatory power of the comprehensive index of ecosystem service function is enhanced or weakened when the driving factors are combined with different combinations, or whether the driving factors themselves are independent variables. The judgment basis of the interaction detector is shown in Table 2 below.

[0093] Table 2 Interaction judgment table of interactive detector driving factors

[0094] Tab.2 Interaction judgment table of driving factors in interactiondetector

[0095]

[0096] From the above description, it can be known that the embodiment of the present invention provides an ecosystem service function evaluation and driving force analysis scheme. The study of ecosystem service functions selects four service function indicators, namely soil conservation service, water conservation service, climate regulation service and biodiversity maintenance service, from the three levels of supply function, regulation function and support function, to comprehensively evaluate the comprehensive function of ecosystem services, analyze the spatiotemporal distribution and evolution characteristics of ecosystem service functions under the comprehensive situation, and draws on the PSR and DPSR analysis models to construct a driving indicator system at the spatial grid scale from the two levels of ecological status such as climate, topography, land use and ecological pressure such as social economy and ecological degradation, which changes the traditional method of excessive use of economic and social indicators and district and county comprehensive indexes in the study of watershed ecosystem services, and makes up for the deficiency of static research only on a certain point in time in the previous analysis of driving forces of geographic spatial indicators.

[0097] Based on the same invention concept, please refer to Figure 2 The embodiment of the present invention also provides an ecosystem service function evaluation system, including:

[0098] The indicator selection unit is used to select four service function indicators from the three types of ecosystem service levels: supply function, regulation function and support function; the four service function indicators include water conservation service indicator, soil conservation service indicator, climate regulation service indicator and biodiversity service indicator;

[0099] The calculation unit is used to calculate the values ​​of the four service function indicators and calculate the comprehensive index value of ecosystem services based on the values ​​of the four service function indicators;

[0100] An evaluation unit is used to evaluate the comprehensive service function of the Three Gorges Reservoir area ecosystem according to the comprehensive index value.

[0101] Furthermore, the above system also includes:

[0102] The driving force analysis unit is used to analyze the driving force of the comprehensive service function of the ecosystem and obtain the driving force analysis results;

[0103] The preprocessing unit is used to standardize the indicator types.

[0104] Wherein, the driving force analysis unit is specifically used for:

[0105] Obtain the current land use data of the Three Gorges Reservoir area, combine the PSR and DPSIR models, and construct a driving factor index system for ecosystem service functions from the two levels of state and pressure; the driving factor index system includes multiple types of driving elements and multiple driving factors;

[0106] The geographic detector was used to detect the spatiotemporal correlation between driving factors and the comprehensive service functions of ecosystems under various types of driving factors, and the degree of spatial analysis explanation of independent variables on dependent variables was measured by the determination power q value.

[0107] It should be noted that for more specific work processes of the system implementation example, please refer to the aforementioned method implementation example section, which will not be repeated here.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for evaluating ecosystem service function, characterized in that: include: A multi-scale spatial analysis method was used, with a 1km*1km grid as the minimum evaluation unit of the index, the county boundaries of administrative divisions as the county-level analysis units, the head, middle and tail of the reservoir as the district-level analysis units, and the entire Three Gorges Reservoir area as the basin-wide analysis unit; Four service function indicators are selected from the three types of ecosystem service levels: supply function, regulation function and support function; the four service function indicators include water conservation service indicator, soil conservation service indicator, climate regulation service indicator and biodiversity service indicator; Calculate the values ​​of four service function indicators; The comprehensive index value of ecosystem services is calculated based on the values ​​of the four service function indicators; After calculating the comprehensive index value of ecosystem services, the method further includes: The Moran index and hot and cold spot pattern analysis methods were used to analyze the temporal evolution characteristics of ecosystem service functions in the Three Gorges Reservoir area under comprehensive conditions. Evaluate the comprehensive service function of the ecosystem in the Three Gorges Reservoir area according to the comprehensive index value; It also includes analyzing the driving forces of the comprehensive service functions of the ecosystem and obtaining the driving force analysis results, specifically: The current land use data of the Three Gorges Reservoir area were obtained, and the PSR and DPSIR models were combined to construct an indicator system of driving factors of ecosystem service functions from the state-pressure level; the indicator system of driving factors includes multiple types of driving factors such as climate conditions, topographic conditions, vegetation status, land use landscape pattern, water system distribution, socio-economic pressure and ecological degradation, as well as multiple driving factors such as average annual precipitation, average annual temperature, topographic position index, vegetation coverage, habitat area ratio, vegetation net primary productivity, landscape type diversity, landscape type uniformity, landscape fragmentation, landscape aggregation, distance from water bodies, population density, GDP, land use intensity, distance from roads, distance from railways, distance from construction land, annual reduction rate of cultivated, forested and grassland, and habitat degradation; The geographic detector was used to detect the spatiotemporal correlation between driving factors and the comprehensive service functions of ecosystems under various types of driving factors, and the degree of spatial analysis explanation of independent variables on dependent variables was measured by the determination power q value.

2. The method according to claim 1, characterized in that The specific values ​​of the four service function indicators are as follows: Formula (1) is used to calculate the value of water conservation service index: WS tr =P tr -AND tr -R tr (1) Among them, WS tr represents the total water conservation supply in grid r in year t, P tr represents the average annual precipitation in grid r in year t, ET tr represents the precipitation evapotranspiration in grid r in year t, R tr It represents the cumulative surface runoff in grid r in year t. The surface runoff is obtained by multiplying precipitation and surface runoff coefficient. Formulas (2) and (3) are used to calculate the value of soil conservation service index: A tr =RE tr ×SE tr ×LS×(1-CCM tr ×CM tr ) (2) Among them, A tr represents the soil conservation scale in grid r in year t, RE tr Represents the rainfall erosivity factor. The rainfall erosivity is calculated using monthly rainfall data. represents the rainfall in the ith month, SE tr represents soil erodibility factor, LS represents slope length and slope factor, CCM tr Represents vegetation cover and management factor, CM tr represents the soil and water conservation measures factor; Formula (4) is used to calculate the value of the climate regulation service index: Among them, C tr represents the total carbon sequestration in grid r in year t, C ti1 represents the aboveground carbon density of land cover type i in year t, C ti2 represents the underground carbon density of land cover type i in year t, C ti3 represents the carbon density of dead organic matter in land cover type i in year t, C ti4 represents the soil organic carbon density of land cover type i in year t, Ar tri Represents the total area of ​​land cover type i in grid r in year t.

3. The method according to claim 2, characterized in that Before calculating the comprehensive index value of ecosystem services, the method further comprises: Formula (5) is used to standardize the indicator type. Sr trj is the standardized value of the jth index in the analysis grid r in the tth year, X trj is the original value of the jth index in the analysis grid r in the tth year, Max(X j ) and Min(X j ) represent the maximum and minimum values ​​of the j index in all years of the study area.

4. The method according to claim 3, characterized in that Formula (6) is used to calculate the comprehensive index value of ecosystem services:

5. The method according to claim 1, characterized in that After constructing the indicator system of driving factors of ecosystem service functions, the method further includes: 19 factors are selected from the 7 element types of the driving force factor index system; among them, the 19 factors include positive factors, reverse factors and moderate factors; The positive factors, negative factors and moderation factors are tempered without any quantity.

6. An ecosystem service function evaluation system, characterized in that: include: The indicator selection unit is used to adopt a multi-scale spatial analysis method, with a 1km*1km grid as the minimum indicator evaluation unit, the district and county boundaries of administrative divisions as district and county scale analysis units, the reservoir head, reservoir middle and reservoir tail as the district-level analysis units, and the entire Three Gorges Reservoir area as the basin-wide analysis unit; four service function indicators are selected from the three types of ecosystem service supply function, regulation function and support function; the four service function indicators include water conservation service indicators, soil conservation service indicators, climate regulation service indicators and biodiversity service indicators; A calculation unit is used to calculate the values ​​of the four service function indicators, and calculate the comprehensive index value of the ecosystem service according to the calculated values ​​of the four service function indicators; after calculating the comprehensive index value of the ecosystem service, the method further includes: The Moran index and hot and cold spot pattern analysis methods were used to analyze the temporal evolution characteristics of ecosystem service functions in the Three Gorges Reservoir area under comprehensive conditions. An evaluation unit, used to evaluate the comprehensive service function of the ecosystem in the Three Gorges Reservoir area according to the comprehensive index value; It also includes a driving force analysis unit, which is used to analyze the driving force of the comprehensive service function of the ecosystem and obtain the driving force analysis results, specifically: The current land use data of the Three Gorges Reservoir area were obtained, and the PSR and DPSIR models were combined to construct an indicator system of driving factors of ecosystem service functions from the state-pressure level; the indicator system of driving factors includes multiple types of driving factors such as climate conditions, topographic conditions, vegetation status, land use landscape pattern, water system distribution, socio-economic pressure and ecological degradation, as well as multiple driving factors such as average annual precipitation, average annual temperature, topographic position index, vegetation coverage, habitat area ratio, vegetation net primary productivity, landscape type diversity, landscape type uniformity, landscape fragmentation, landscape aggregation, distance from water bodies, population density, GDP, land use intensity, distance from roads, distance from railways, distance from construction land, annual reduction rate of cultivated, forested and grassland, and habitat degradation; The geographic detector was used to detect the spatiotemporal correlation between driving factors and the comprehensive service functions of ecosystems under various types of driving factors, and the degree of spatial analysis explanation of independent variables on dependent variables was measured by the determination power q value.

7. The system according to claim 6, characterized in that Also included is a pre-processing unit for: Formula (5) is used to standardize the indicator type. Sr trj is the standardized value of the jth index in the analysis grid r in the tth year, X trj is the original value of the jth index in the analysis grid r in the tth year, Max(X j ) and Min(X j ) represent the maximum and minimum values ​​of the j index in all years of the study area.

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