Ecological protection priority zone identification method considering time dynamics

Abstract

The invention is suitable for the technical field of ecological space planning, and provides an ecological protection priority area identification method considering time dynamics, which comprises the following steps: acquiring spatial distribution data of a research area and preprocessing the spatial distribution data; selecting ecological system service indexes, and evaluating and standardizing the indexes according to the preprocessed data; calculating the importance of the standardized index values in an equal weight superposition mode and performing standardization processing; calculating an ecological system service urgency index; performing cold and hot spot analysis on the ecological system service urgency index, extracting a cold spot region, determining a minimum area threshold by using a piecewise linear regression method, and extracting plaques greater than the minimum area threshold as an ecological protection priority region. According to the method, the ecosystem service urgency index is constructed through the ecosystem service importance of multiple time sequences, the problem that the change of the ecosystem service function along with time in the prior art is ignored is effectively avoided, and the method has important significance for promoting the sustainability of regional ecological protection planning.

Description

Technical Field

[0001] The present invention belongs to the technical field of ecological space planning, and in particular relates to a method for identifying ecological protection priority areas taking into account time dynamics. Background Art

[0002] Formulating scientific ecological space management and planning based on ecosystem functions is an effective way to promote sustainable development of ecosystems. Ecological protection priority areas are key ecological protection areas delineated based on the natural conditions and socioeconomic conditions of the region for the purpose of protecting natural resources and ensuring regional ecological security. These areas have good ecosystem integrity and the ability to self-maintain and regulate, and can provide stable and sustainable ecosystem functions, which are helpful to maintain regional ecosystem stability, alleviate ecological degradation pressure and enhance ecosystem service functions. In view of the complexity of regional ecosystems themselves and the combined impact of climate change and human activities, the current identification methods of ecological protection priority areas still need to be continuously studied in depth. How to scientifically explore and determine ecological priority protection areas, identify areas that continuously provide ecosystem services and are spatially concentrated and contiguous, and implement targeted protection is of great significance for optimizing the layout of ecological space and rationally formulating ecological space governance policies, thereby ensuring regional ecological security and sustainable development.

[0003] The existing methods for identifying and delineating priority areas for ecological protection are mainly based on ecological environmental assessments based on special ecological protection projects or ecosystem services, ecosystem health, and ecosystem vulnerability. On this basis, ecological protection levels are divided and priority areas are determined based on ecological control space or evaluation results. Compared with the delineation of priority areas based on ecological control space, this method can better reflect the spatial heterogeneity and comprehensive characteristics of the ecosystem, and has become the main method for identifying priority areas.

[0004] However, existing research still lacks consideration of the temporal heterogeneity of ecosystem functions, that is, it ignores the fact that ecosystem service functions will change over time. Ecological protection priority areas based on static identification methods may affect the sustainability of priority areas, making them unable to play an important role in maintaining the stability and integrity of regional ecosystems, and may also lead to certain deviations in the formulation of ecological management strategies. Therefore, the temporal changes in ecosystem service functions are crucial to ecological protection and ecological space planning. How to provide a priority area identification method that fully considers dynamic changes or its temporal heterogeneity characteristics is an urgent problem that technicians in this field need to solve. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a method for identifying ecological protection priority areas that takes into account temporal dynamics, aiming to solve the technical problems of instability and unsustainability of ecological protection priority areas caused by the lack of consideration of the dynamic changing properties of ecosystem services and functions over time in the prior art.

[0006] The present invention adopts the following technical solution:

[0007] The method for identifying ecological protection priority areas taking into account time dynamics comprises the following steps:

[0008] Step S1, obtaining spatial distribution data of ecological protection research areas in different years and preprocessing the spatial distribution data;

[0009] Step S2, selecting multiple time series ecosystem service indicators, evaluating the indicators based on the preprocessed data, and standardizing the indicator values ​​of the evaluation results;

[0010] Step S3, the standardized indicator values ​​are superimposed by equal weights to calculate the superposition results as the importance of ecosystem services in multiple time series, and then standardized;

[0011] Step S4, calculating the ecosystem service urgency index according to the standardized ecosystem service importance;

[0012] Step S5: perform hot and cold spot analysis on the ecosystem service urgency index and extract cold spot areas, use piecewise linear regression method to determine the minimum area threshold, and extract patches larger than the minimum area threshold as ecological protection priority areas.

[0013] Furthermore, in step S1, the spatial distribution data is preprocessed including data coordinate system conversion, resampling and clipping operations.

[0014] Furthermore, the specific process of step S2 is as follows:

[0015] S21. Based on the characteristics of the ecosystem in the ecological protection study area and the ecological problems it faces, select ecosystem service indicators suitable for the selected study area, determine the evaluation method according to the data characteristics of each indicator, evaluate the ecosystem service indicators based on the pre-processed data in interval years, and obtain the evaluation result index value of each indicator;

[0016] S22. The evaluation result index values ​​are standardized by the range method. After standardization, the index values ​​of each index are between 0 and 1. The standardization method is as follows:

[0017]

[0018] Among them, X nor is the index value after standardization, Xx is the current indicator value, X max is the maximum value of the indicator, X min is the minimum value of the indicator.

[0019] Furthermore, in step S21, the selected ecosystem service indicators include habitat quality, water production service, soil conservation service and carbon sequestration service, among which the habitat quality is evaluated by the habitat quality module in the InVEST model; the water production service is evaluated by the water production module in the InVEST model; the soil conservation service is evaluated by the modified general soil and water loss equation; and the carbon sequestration service is evaluated by the net primary productivity of vegetation.

[0020] Furthermore, the specific process of step S3 is as follows:

[0021] S31. Perform equal-weighted superposition calculation on the standardized ecosystem service index values ​​of each interval year, and the superposition result is used as the importance of ecosystem services in the ecological protection study area:

[0022]

[0023] Among them, ESI is the importance of ecosystem services at the current time snapshot. is the standardized indicator value of the ith ecosystem service indicator;

[0024] S32. Standardize the importance of ecosystem services in each interval year using the range method so that the standardized results are between 0 and 1.

[0025] Furthermore, there are three interval years, which are respectively recorded as year A, year B and year C. According to the importance of ecosystem services in the ecological protection study area in the three years, in step S4, ArcGIS software is used to calculate the ecosystem service urgency index:

[0026]

[0027] Among them, ESI A 、ESI B and ESI C The standardized results of ecosystem service importance in year A, year B and year C, and are the average values ​​of the differences in ecosystem service importance from year A to year B and from year B to year C, and are the standard deviations of the differences in ecosystem service importance from year A to year B and from year B to year C, respectively.

[0028] Furthermore, the specific process of step S5 is as follows:

[0029] S51. Use ArcGIS software to convert the raster data of the ecosystem service urgency index into shapefile vector data;

[0030] S52, using the hot and cold spot analysis tool in ArcGIS software to perform hot and cold spot analysis on the vector data to analyze the clustering characteristics of the ecosystem service urgency index;

[0031] S53, extract the cold spot area with a confidence level of 99% from the hot and cold spot analysis results, use the fusion tool to fuse them, and the fusion result is the preliminary identification of the ecological protection priority area;

[0032] S54. Use ArcGIS software to calculate the area of ​​the ecological protection priority zone for preliminary identification, set the step size to count the number of patches and the total area of ​​patches that are higher than the preset area threshold, use the segmented linear regression method of the "Segmented" package in the R language to monitor the relationship between the preset area threshold and the number of patches, as well as the preset area threshold and the total area of ​​patches, find the change point and determine the minimum area threshold of the ecological protection priority zone;

[0033] S55. Extract patches whose areas are larger than the minimum area threshold as the ecological protection priority areas to be finally identified.

[0034] The beneficial effects of the present invention are:

[0035] The present invention firstly calculates the importance of ecosystem services and takes the result as the basis for subsequent analysis, thereby overcoming the spatial differences in ecological processes under the same land use type; furthermore, it constructs an ecosystem service urgency index that can effectively reflect the loss or gain of ecosystem service functions over time, and combines it with hot and cold spot analysis methods to identify dynamically changing and sustainable ecological protection priority areas for ecosystem services. This can more objectively characterize the changing characteristics of the importance of ecosystem services in time series, and solves the problem that the existing priority area identification technology does not take into account its temporal heterogeneity.

[0036] The method of the present invention is simple, fast and flexible in calculation, and can help decision makers quickly and accurately identify priority protection spaces that can sustainably provide ecosystem services in dynamic changes, and provide valuable spatial guidance for the formulation of targeted and sustainable protection measures in ecological planning. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a flow chart of a method for identifying ecological protection priority areas taking into account time dynamics provided by an embodiment of the present invention;

[0038] Figure 2is a distribution diagram of the ecosystem service urgency index in an embodiment of the present invention;

[0039] Figure 3 is a hot and cold spot analysis result diagram in an embodiment of the present invention;

[0040] Figure 4 It is a distribution map of ecological protection priority areas identified according to the method of the present invention in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] In order to illustrate the technical solution of the present invention, a specific embodiment is provided below for illustration.

[0043] like Figure 1 As shown, the method for identifying ecological protection priority areas taking into account time dynamics provided in this embodiment includes the following steps:

[0044] Step S1, obtaining the spatial distribution data of the ecological protection research area in different years and preprocessing the spatial distribution data.

[0045] In this step, the area to be studied is first selected, namely the ecological protection study area. Spatial distribution data of the study area for many years is collected, such as relevant spatial distribution data of the study area between 2000 and 2020. Spatial distribution data is preprocessed, such as coordinate system conversion, resampling, and clipping, to ensure that the multi-time series data maintain a unified projection coordinate system, spatial resolution, and spatial range.

[0046] Step S2: select multiple time series ecosystem service indicators, evaluate the indicators based on the preprocessed data, and standardize the indicator values ​​of the evaluation results.

[0047] This step selects ecosystem service indicators from the aspects of supply services, regulation services and support services of ecosystem services, and determines the evaluation method based on the data characteristics of each indicator, obtains the evaluation results of each indicator, and finally standardizes the indicator values ​​of the evaluation results. Specifically, the process of this step is as follows:

[0048] S21. Based on the ecosystem characteristics of the ecological protection study area and the ecological problems it faces, select ecosystem service indicators suitable for the selected study area, determine the evaluation method based on the data characteristics of each indicator, and evaluate the ecosystem service indicators based on the pre-processed data at intervals to obtain the evaluation result indicator value of each indicator.

[0049] For example, the ecosystem service indicators are evaluated according to the three interval years of 2000, 2010 and 2020. First, we need to select the ecosystem service indicators suitable for the selected study area. The selected ecosystem services in this embodiment include: habitat quality, water production service, soil conservation service and carbon sequestration service. Then, the evaluation method is determined for the four service indicators according to the data characteristics. In this embodiment, the habitat quality is evaluated by the habitat quality module in the InVEST model; the water production service is evaluated by the water production module in the InVEST model; the soil conservation service is evaluated by the modified universal soil erosion equation (RUSLE); and the carbon sequestration service is evaluated by the net primary productivity of vegetation.

[0050] S22. The evaluation result index values ​​are standardized by the range method. After standardization, the index values ​​of each index are between 0 and 1. The standardization method is as follows:

[0051]

[0052] Among them, X nor is the index value after standardization, X x is the current indicator value, X max is the maximum value of the indicator, X min is the minimum value of the indicator.

[0053] In this step, ArcGIS software was used to standardize the evaluation results of the four ecosystem service indicators in 2000, 2010, and 2020 using the range method. After standardization, the values ​​of each indicator were between 0 and 1.

[0054] Step S3: Calculate the superposition results of the standardized indicator values ​​by equal weight superposition as the importance of ecosystem services in multiple time series, and perform standardized processing.

[0055] This step designs an important data, the importance of ecosystem services. The present invention bases the analysis on the evaluation of the importance of ecosystem services. The specific process of step S3 is as follows:

[0056] S31. Perform equal-weighted superposition calculation on the standardized ecosystem service index values ​​of each interval year, and the superposition result is used as the importance of ecosystem services in the ecological protection study area:

[0057]

[0058] Among them, ESI is the importance of ecosystem services at the current time snapshot. is the standardized indicator value of the ith ecosystem service indicator.

[0059] In this step, the index values ​​of each ecosystem service indicator that has been standardized in 2000, 2010 and 2020 are equally weighted and superimposed to obtain the importance of ecosystem services in the study area in 2000, 2010 and 2020.

[0060] S32. Standardize the importance of ecosystem services in each interval year using the range method so that the standardized results are between 0 and 1.

[0061] In this step, the importance of ecosystem services is standardized by the range method, and the processing method is similar to that of step S22, that is, the difference between the maximum value and the current value is divided by the difference between the maximum value and the minimum value.

[0062] Step S4: Calculate the ecosystem service urgency index based on the standardized ecosystem service importance.

[0063] For ease of description, this example records the three interval years of 2000, 2010 and 2020 as Year A, Year B and Year C respectively. ArcGIS software is used to calculate the ecosystem service urgency index based on the importance of ecosystem services in the ecological protection study area in the three years:

[0064]

[0065] Among them, ESI A 、ESI B and ESI C The standardized results of ecosystem service importance in year A, year B and year C, and are the average values ​​of the differences in ecosystem service importance from year A to year B and from year B to year C, and are the standard deviations of the differences in ecosystem service importance from year A to year B and from year B to year C, respectively.

[0066] The formula represents the calculation of the difference based on the standardized results of the importance of ecosystem services in different interval years, and the standard scores of the difference are reversed and added. The "-1" multiplied by the two terms in the formula represents the reversal of the positive and negative signs. A positive ESUI indicates that the importance of ecosystem services decreases over time and the ecosystem service function is lost. The higher the ESUI, the greater the loss of the corresponding ecosystem service function over time. A negative ESUI indicates that the importance of ecosystem services increases over time.

[0067] The spatial distribution of the ecosystem service urgency index in the study area calculated is as follows: Figure 2 shown.

[0068] Step S5: perform hot and cold spot analysis on the ecosystem service urgency index and extract cold spot areas, use piecewise linear regression method to determine the minimum area threshold, and extract patches larger than the minimum area threshold as ecological protection priority areas.

[0069] This step conducts hot and cold spot analysis on the ecosystem service urgency index and extracts the cold spot area. The minimum area threshold is determined using the piecewise linear regression method, and patches larger than the minimum area threshold are extracted as the identification results of the ecological protection priority areas taking into account the temporal dynamics. The specific process is as follows:

[0070] S51. Use ArcGIS software to convert the raster data of the ecosystem service urgency index into shapefile vector data.

[0071] S52. Use the hotspot and coldspot analysis tool in ArcGIS software to perform hotspot and coldspot analysis on the vector data to analyze the clustering characteristics of the ecosystem service urgency index.

[0072] Use the hotspot analysis tools in ArcGIS software, such as the Getis-Ord Gi* analysis tool, to analyze the vector data of the ecosystem service urgency index and determine the clustering characteristics of the ESUI value. The hotspot analysis results are shown in the figure below. Figure 3 shown.

[0073] S53. Extract the cold spot areas with a confidence level of 99% from the cold and hot spot analysis results, and use the fusion tool to fuse them. The fusion result is the preliminary identification of the ecological protection priority areas.

[0074] The cold and hot spot analysis tool in ArcGIS software was used to conduct a cold and hot spot analysis of ESUI, extract the cold spot areas with a confidence level of 99%, and fuse them to obtain a relatively complete preliminary identification of ecological protection priority areas.

[0075] S54. Use ArcGIS software to calculate the area of ​​the ecological protection priority zone for preliminary identification, set the step size to count the number of patches and the total area of ​​patches that are higher than the preset area threshold, and use the segmented linear regression method of the "Segmented" package in the R language to monitor the relationship between the preset area threshold and the number of patches, as well as the preset area threshold and the total area of ​​patches, to find the change point and determine the minimum area threshold of the ecological protection priority zone.

[0076] For example, 1km 2 The initial preset area threshold is set with a step size of 1 km. The number of patches and the total area of ​​patches above the preset area threshold are counted. Then, the relationship between the preset area threshold and the number of patches and the total area of ​​patches is monitored using the piecewise linear regression method. The minimum area threshold of the ecological protection priority zone is determined based on the change point. 2 is the step length, and the preset area threshold is 1km2 , 2km 2 , 3km 2 ..., we get two sets of data sets, area threshold and number of plaques, and area threshold and total plaque area, and perform piecewise linear regression on each set of data sets. Specifically, by analyzing the distribution of data in the data set, we find the inflection point of data change as the initial breakpoint, divide the data into different intervals, establish a piecewise linear regression model, and use the least squares method to evaluate the model (such as residual sum of squares, determination coefficient and other indicators) and optimize it. By analyzing the results of the piecewise linear regression model, we determine the final change point (i.e., turning point or critical point) of the number of plaques and the total area of ​​plaques with the preset area threshold, and the average value of the area thresholds corresponding to the two final change points is used as the reference value of the minimum area threshold.

[0077] S55, extracting patches with an area greater than the minimum area threshold as the final identified ecological protection priority area, the result is as follows Figure 4 shown.

[0078] In summary, the method of the present invention is based on multi-year ecosystem service importance assessment. By constructing an ecosystem service urgency index that can reflect its temporal dynamic changes, combined with hot and cold spot analysis methods, it identifies sustainable ecological protection priority areas that take into account the dynamic changes of ecosystem services. It solves the problem that the temporal heterogeneity of priority area identification technology is not taken into account, and provides technical support for regional ecological protection and restoration as well as sustainable development.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for identifying ecological protection priority areas taking into account temporal dynamics, characterized in that: The method for identifying ecological protection priority areas comprises the following steps: Step S1, obtaining spatial distribution data of ecological protection research areas in different years and preprocessing the spatial distribution data; Step S2, selecting multiple time series ecosystem service indicators, evaluating the indicators based on the preprocessed data, and standardizing the indicator values ​​of the evaluation results; Step S3, the standardized indicator values ​​are superimposed by equal weights to calculate the superposition results as the importance of ecosystem services in multiple time series, and then standardized; Step S4, calculating the ecosystem service urgency index according to the standardized ecosystem service importance; Step S5: perform hot and cold spot analysis on the ecosystem service urgency index and extract cold spot areas, use piecewise linear regression method to determine the minimum area threshold, and extract patches larger than the minimum area threshold as ecological protection priority areas.

2. The method for identifying ecological protection priority areas taking into account time dynamics as claimed in claim 1, characterized in that: In step S1, the spatial distribution data is preprocessed including data coordinate system conversion, resampling and clipping operations.

3. The method for identifying ecological protection priority areas taking into account time dynamics as claimed in claim 2, characterized in that: The specific process of step S2 is as follows: S21. Based on the characteristics of the ecosystem in the ecological protection study area and the ecological problems it faces, select ecosystem service indicators suitable for the selected study area, determine the evaluation method according to the data characteristics of each indicator, evaluate the ecosystem service indicators based on the pre-processed data in interval years, and obtain the evaluation result index value of each indicator; S22. The evaluation result index values ​​are standardized by the range method. After standardization, the index values ​​of each index are between 0 and 1. The standardization method is as follows: Among them, X nor is the index value after standardization, X x is the current indicator value, X max is the maximum value of the indicator, X min is the minimum value of the indicator.

4. The method for identifying ecological protection priority areas taking into account time dynamics as claimed in claim 3, characterized in that: In step S21, the selected ecosystem service indicators include habitat quality, water production service, soil conservation service and carbon sequestration service, among which the habitat quality is evaluated by the habitat quality module in the InVEST model; the water production service is evaluated by the water production module in the InVEST model; the soil conservation service is evaluated by the modified general soil and water loss equation; and the carbon sequestration service is evaluated by the net primary productivity of vegetation.

5. The method for identifying ecological protection priority areas taking into account time dynamics as claimed in claim 4, characterized in that: The specific process of step S3 is as follows: S31. Perform equal-weighted superposition calculation on the standardized ecosystem service index values ​​of each interval year, and the superposition result is used as the importance of ecosystem services in the ecological protection study area: Among them, ESI is the importance of ecosystem services at the current time snapshot. is the standardized indicator value of the ith ecosystem service indicator; S32. Standardize the importance of ecosystem services in each interval year using the range method so that the standardized results are between 0 and 1.

6. The method for identifying ecological protection priority areas in a time-dynamic manner as claimed in claim 5, characterized in that: There are three interval years, which are respectively recorded as year A, year B and year C. According to the importance of ecosystem services in the ecological protection study area in the three years, in step S4, ArcGIS software is used to calculate the ecosystem service urgency index: Among them, ESI A 、ESI B and ESI C The standardized results of ecosystem service importance in year A, year B and year C, and are the average values ​​of the differences in ecosystem service importance from year A to year B and from year B to year C, σ dESIAB and σ dESIBC are the standard deviations of the differences in ecosystem service importance from year A to year B and from year B to year C, respectively.

7. The method for identifying ecological protection priority areas in a time-dynamic manner as claimed in claim 6, characterized in that: The specific process of step S5 is as follows: S51. Use ArcGIS software to convert the raster data of the ecosystem service urgency index into shapefile vector data; S52, using the hot and cold spot analysis tool in ArcGIS software to perform hot and cold spot analysis on the vector data to analyze the clustering characteristics of the ecosystem service urgency index; S53, extract the cold spot area with a confidence level of 99% from the cold and hot spot analysis results, use the fusion tool to fuse them, and the fusion result is the preliminary identification of the ecological protection priority area; S54. Use ArcGIS software to calculate the area of ​​the ecological protection priority zone for preliminary identification, set the step size to count the number of patches and the total area of ​​patches that are higher than the preset area threshold, use the segmented linear regression method of the "Segmented" package in the R language to monitor the relationship between the preset area threshold and the number of patches, as well as the preset area threshold and the total area of ​​patches, find the change point and determine the minimum area threshold of the ecological protection priority zone; S55. Extract patches whose areas are larger than the minimum area threshold as the ecological protection priority areas to be finally identified.

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