Ecological buffer zone planning method

Abstract

The invention relates to the technical field of buffer zone planning, and particularly discloses an ecological buffer zone planning method, which comprises the following steps: acquiring remote sensing image data and hydrological data of a target river and lake area for determining the type of a river and lake shore zone and the range of a water level amplitude variation area; calculating the width of a land area buffer area by combining slope data and land utilization type data on the basis of the type of the river and lakeshore zone and the range of the water level amplitude variation zone, and generating a preliminary buffer zone range; the preliminary buffer zone range is calibrated, manual adjustment is carried out in combination with a river and lake management shoreline and a land utilization type map, and a final ecological buffer zone range is determined; according to the method, the improved normalized water body index is combined with the dynamic threshold segmentation technology, the water body and the vegetation coverage area are effectively distinguished, and the misjudgment risk caused by vegetation or terrain interference in a traditional method is reduced. The technology can adapt to water body changes under different seasons and climate conditions, the scientificity and consistency of water level variable amplitude area demarcation are ensured, and a reliable space basis is provided for the buffer zone range.

Description

Technical Field

[0001] The present invention belongs to the technical field of buffer zone planning, and particularly relates to an ecological buffer zone planning method. Background Art

[0002] River and lake shore zones can be divided into two major categories: ecological protection type and ecological restoration type according to factors such as the degree of interference of human activities on the river and lake shore zones, the land use patterns of the river and lake shore zones, and the characteristics of ecological degradation. Among them, the ecological protection type of river and lake shore zones refers to the type with a relatively good current ecological environment, no human interference, or only mild interference. The ecological restoration type of river and lake shore zones refers to the type that has different degrees of ecological degradation due to human interference and requires ecological restoration measures.

[0003] In view of this, the inventor proposes an ecological buffer zone planning method to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide an ecological buffer zone planning method to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] An ecological buffer zone planning method, comprising:

[0007] Obtaining remote sensing image data and hydrological data of the target river and lake area for determining the river and lake shore zone type and the water level fluctuation zone range;

[0008] Based on the river and lake shore zone type and the water level fluctuation zone range, combining slope data and land use type data, calculating the width of the land buffer zone, and generating a preliminary buffer zone range;

[0009] Calibrating the preliminary buffer zone range, and making manual adjustments in combination with the river and lake management shoreline and the land use type map to determine the final ecological buffer zone range.

[0010] Preferably, the step of obtaining remote sensing image data and hydrological data of the target river and lake area includes:

[0011] Importing the remote sensing image data of the target river and lake area, and generating a preprocessed remote sensing image through radiometric calibration, atmospheric correction, and cloud removal processing;

[0012] Based on the preprocessed remote sensing image, using the water body index method to extract the historical highest water level line and the lowest water level line, and demarcating the water level fluctuation zone range;

[0013] According to the land use pattern and the characteristics of ecological degradation of the river and lake shore zone, classifying the river and lake shore zone as an ecological protection type or an ecological restoration type.

[0014] Preferably, the radiometric calibration includes converting the original DN value of the remote sensing image into surface reflectance;

[0015] The atmospheric correction uses the FLAASH model to eliminate the influence of aerosols and atmospheric scattering;

[0016] The cloud removal process eliminates invalid data in the cloud-covered area through a cloud mask tool.

[0017] Preferably, the water body index method uses the Modified Normalized Difference Water Index (MNDWI), and extracts the water body boundary through threshold segmentation, and combines remote sensing data of the past two decades to invert the historical water level line.

[0018] Preferably, the optimized formula of the Modified Normalized Difference Water Index is:

[0019]

[0020] where ρgreen: surface reflectance in the green light band (such as Band 3 of Landsat 8, wavelength 0.53–0.59 μm);

[0021] ρmid-infrared: surface reflectance in the mid-infrared band (such as Band 6 of Landsat 8, wavelength 1.57–1.65 μm).

[0022] Preferably, the calculation method of the land buffer zone width includes:

[0023] For ecologically protected river and lake shore zones, the buffer zone is delimited according to the vegetation cover type, desert or rock characteristics, and the recommended width value;

[0024] For ecologically restored river and lake shore zones, based on the slope interpolation method, empirical value method or model simulation method, the buffer zone width is determined in combination with the agricultural non-point source pollution control target;

[0025] For composite river and lake shore zones, the buffer zone width is determined according to the shore zone type with the highest area ratio.

[0026] Preferably, the slope interpolation method is: converting the ASTER GDEM digital elevation data into slope data, overlaying it with the buffer zone type distribution map, and performing interpolation calculation according to the slope value and the recommended width table;

[0027] The formula of the slope interpolation method is

[0028] Buffer zone width = W 基准 + k·S

[0029] where Wreference: the reference width when the slope is 0 (such as the recommended value 1 for farmland-type shore zones is 20 m, and the recommended value 2 is 30 m);

[0030] S: Slope value, unit: degree;

[0031] k: Slope adjustment coefficient, -0.5 for sandy soil, +0.5 for clay soil, 0 for loam soil.

[0032] Preferably, the determination of the final ecological buffer zone range includes:

[0033] Compare the preliminary buffer zone range with the river and lake management shoreline, and artificially fill the areas with gaps.

[0034] Eliminate the areas that exceed the river and lake management shoreline and whose land use types are cultivated land and industrial and mining land, and retain the wetland, forest land and grassland areas to generate the final buffer zone range.

[0035] If the river management shoreline is not delimited in the target river section, the buffer zone boundary is determined by using the riparian ecosystem management model or the empirical value method.

[0036] Preferably, the formula of the riparian ecosystem management model is:

[0037]

[0038] Where Q: Annual average runoff, m 3 / s;

[0039] C: Pollutant concentration, mg / L;

[0040] R: Vegetation filtration efficiency coefficient, 0.6 for grassland, 0.8 for shrubs, 0.9 for trees;

[0041] V: Surface runoff velocity, m / s;

[0042] K: Soil adsorption coefficient, 0.3 for sandy soil, 0.7 for clay soil.

[0043] Compared with the prior art, the beneficial effects of the present invention are:

[0044] (1) By combining the improved normalized water index with the dynamic threshold segmentation technology, the present invention effectively distinguishes the water body and the vegetation-covered area, significantly reducing the misjudgment risk caused by vegetation or terrain interference in the traditional method. This technology can adapt to the water body changes under different seasons and climate conditions, ensuring the scientificity and consistency of the delineation of the water level fluctuation zone, and providing a reliable spatial basis for the buffer zone range.

[0045] (2) The present invention realizes the dynamic adjustment of the buffer zone width through the coupled calculation of slope interpolation method and soil type correction. By integrating parameters such as terrain slope and soil permeability, it can flexibly adapt to the requirements of different geographical environments. For example, in steep slope or clay areas, the buffer zone width is appropriately increased to enhance the pollutant interception ability; in sandy soil or flat areas, the width is optimized to reduce the occupation of farmland or construction land, and balance the conflict between ecological protection and land use.

[0046] (3) The present invention introduces an ecological management model for the riparian zone, comprehensively considering multiple environmental factors such as hydrology, vegetation cover, and soil properties, and quantifies the pollutant interception efficiency of the buffer zone. This model provides theoretical support for the design of the buffer zone width by dynamically simulating the pollutant migration law under different scenarios, avoiding the blindness of the traditional empirical value method, and improving the scientificity and economy of the planning. Brief Description of the Drawings

[0047] Figure 1 A method for planning an ecological buffer zone of the present invention;

[0048] Figure 2 The water body reflection spectral curve in the second embodiment of the present invention;

[0049] Figure 3 The water body index map in the second embodiment of the present invention. Detailed Embodiments

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0051] Embodiment 1:

[0052] Please refer to Figure 1 shown, a method for planning an ecological buffer zone, including:

[0053] Obtain remote sensing image data and hydrological data of the target river-lake area to determine the river-lake riparian zone type and the water level fluctuation area range;

[0054] Based on the river-lake riparian zone type and the water level fluctuation area range, combined with slope data and land use type data, calculate the width of the land buffer zone and generate the preliminary buffer zone range;

[0055] Calibrate the preliminary buffer zone range, and make manual adjustment in combination with the river-lake management shoreline and the land use type map to determine the final ecological buffer zone range.

[0056] Specifically, the steps of obtaining remote sensing image data and hydrological data of the target river and lake area include:

[0057] Import remote sensing image data of the target river and lake area, and generate pre-processed remote sensing images through radiometric calibration, atmospheric correction and cloud removal.

[0058] Based on the pre-processed remote sensing image, the historical highest water level and the lowest water level are extracted using the water body index method to delineate the water level variation range;

[0059] According to the land use patterns and ecological degradation characteristics of river and lake shorelines, river and lake shorelines are classified as ecological protection type or ecological restoration type.

[0060] Specifically, the radiometric calibration includes converting the original DN value of the remote sensing image into surface reflectivity;

[0061] The atmospheric correction adopts FLAASH model to eliminate the influence of aerosol and atmospheric scattering;

[0062] The cloud removal process removes invalid data in cloud-covered areas using a cloud mask tool.

[0063] Specifically, the water index method adopts the modified normalized difference water index (MNDWI), extracts water body boundaries through threshold segmentation, and combines remote sensing data from the past two decades to invert historical water levels.

[0064] Specifically, the optimization formula of the improved normalized water index is:

[0065]

[0066] Where ρ green light: the surface reflectance in the green band (such as Band 3 of Landsat 8, wavelength 0.53–0.59 μm);

[0067] ρ mid-infrared: surface reflectance in the mid-infrared band (such as Band 6 of Landsat 8, wavelength 1.57–1.65 μm).

[0068] Specifically, the calculation method of the land buffer zone width includes:

[0069] For ecologically protected river and lakeshore zones, buffer zones are delineated according to the vegetation cover type, desert or rock characteristics, and preset width recommended values;

[0070] For ecologically restored river and lakeshore zones, the width of the buffer zone is determined based on slope interpolation, empirical value method, or model simulation method, combined with the goal of controlling agricultural non-point source pollution;

[0071] For complex river and lake shorelines, the buffer zone width is determined based on the shoreline type with the highest area proportion.

[0072] Specifically, the slope interpolation method is as follows: converting the ASTER GDEM digital elevation data into slope data, overlaying it with the buffer zone type distribution map, and performing interpolation calculations according to the slope value and the preset width recommendation table;

[0073] The formula for the slope interpolation method is

[0074] Buffer zone width = W 基准 + k·S

[0075] where W reference: the reference width when the slope is 0 (for example, the recommended value 1 for the farmland-type shore zone is 20m, and the recommended value 2 is 30m);

[0076] S: slope value, unit: degree;

[0077] k: slope adjustment coefficient, -0.5 for sandy soil, +0.5 for clay soil, and 0 for loam soil.

[0078] Specifically, the determination of the final ecological buffer zone range includes:

[0079] Comparing the preliminary buffer zone range with the river and lake management shoreline, and artificially filling the areas with gaps;

[0080] Eliminating the areas that exceed the river and lake management shoreline and whose land use types are cultivated land and industrial and mining land, and retaining the wetland, forest land, and grassland areas to generate the final buffer zone range;

[0081] If the river and lake management shoreline has not been delimited for the target river section, the riverbank ecosystem management model or the empirical value method is used to determine the buffer zone boundary.

[0082] The formula for the riverbank ecosystem management model is:

[0083]

[0084] where Q: annual average runoff, m 3 / s;

[0085] C: pollutant concentration, mg / L;

[0086] R: vegetation filtration efficiency coefficient, 0.6 for grassland, 0.8 for shrubs, and 0.9 for trees;

[0087] V: surface runoff velocity, m / s;

[0088] K: soil adsorption coefficient, 0.3 for sandy soil, 0.7 for clay soil.

[0089] As can be seen from the above, by combining the improved normalized difference water index with the dynamic threshold segmentation technology, the water body and vegetation-covered areas can be effectively distinguished, and the misjudgment risk caused by vegetation or terrain interference in the traditional method can be significantly reduced. This technology can adapt to water body changes under different seasons and climate conditions, ensure the scientificity and consistency of the delineation of the water level fluctuation zone, and provide a reliable spatial basis for the buffer zone range.

[0090] Based on the coupled calculation of slope interpolation method and soil type correction, the dynamic adjustment of the buffer zone width is realized. By integrating parameters such as terrain slope and soil permeability, it can flexibly adapt to the needs of different geographical environments. For example, in steep slope or clay areas, the buffer zone width is appropriately increased to enhance the pollutant interception ability; in sandy soil or flat areas, the width is optimized to reduce the occupation of farmland or construction land and balance the conflict between ecological protection and land use.

[0091] Introduce the riparian ecosystem management model, comprehensively consider multiple environmental factors such as hydrology, vegetation cover, and soil characteristics, and quantify the pollutant interception efficiency of the buffer zone. This model dynamically simulates the pollutant migration law under different scenarios, provides theoretical support for the buffer zone width design, avoids the blindness of the traditional empirical value method, and improves the scientificity and economy of the planning.

[0092] Example 2:

[0093] Method for delineating the water level fluctuation zone

[0094] The range of the water level fluctuation zone is determined according to the area between the lowest water level line and the highest water level line during the flood period of the target river. The "Technical Guide for the Protection and Restoration of River and Lake Ecological Buffer Zones" recommends using the multi-year average lowest water level line and the multi-year average highest water level line. It is preferred to use hydrological station data for judgment. If there is no hydrological station data, remote sensing data for the past 20 years can be used for inversion judgment. This method determines the historical highest water level line and the lowest water level line of the river by investigating and collecting historical remote sensing images within the river basin range, and takes the area between the highest water level line and the lowest water level line as the range of the river water level fluctuation zone. The specific operation process is as follows:

[0095] Import data: Start ENVI, file—Open As, select the appropriate sensor according to the image. Here, select the tiff image with source data of Landsat under the optical sensor; File—Open As—Optical Sensors—Landsat—Geo TIFF with Metadata, and import the MTL.txt file (image metadata, header file).

[0096] Image preprocessing:

[0097] Image preprocessing includes six steps: geometric correction, terrain correction, radiometric calibration, atmospheric correction, cloud removal (cloud masking), and image fusion. The source of the image data for this time is Landsat 8, so geometric correction and terrain correction are not required.

[0098] (1) Radiometric calibration

[0099] Purpose: Convert the original pixel brightness DN value (recording the ground object gray value, that is, the digital measurement value obtained by the sensor) to the surface reflectance or a relative value related to physical quantities such as surface temperature; convert the brightness gray value of the image to the absolute radiance.

[0100] Operation: Find Toolbox – Radiometric Correction – Radiometric Calibration on the right side of the envi interface;

[0101] Select the multispectral image for calibration and click OK.

[0102] (2) Atmospheric correction

[0103] Toolbox – Radiometric Correction — Atmospheric CorrectionModule — FLAASH (FLAASH Atmospheric Correction), open the atmospheric correction parameter panel

[0104] Input Radiance Image: Select the image after radiometric calibration in the previous step, and select use single scale factor for all bands in the pop-up dialog box;

[0105] Output Reflectance File: Output the reflectance range file and set the output path; PS: The output result is by default the scaled reflectance data (magnified 10,000 times), and the range of its pixel values is from 0 to 10,000 (representing 0 to 100% reflectance). Some pixels may be outside this range. These outliers are usually located on highly reflective surfaces with high saturation or in dark pixels. Negative values usually appear in deep water or shadows with low reflectance. To scale the pixel values to between 0 and 1, the Band Math tool can be used for band operation, and the formula is b1 / 10000.0, where b1 is specified as the entire file.

[0106] Output Directory for FLAASH Files: Output directory for atmospheric correction files;

[0107] Rootname for FLAASH Files: Atmospheric correction file naming;

[0108] Sensor Type: sensor type, select the type corresponding to the image;

[0109] Flight Date: time, right-click the layer - view metadata - time to view the time;

[0110] Ground Elevation: Average altitude, view the average altitude:

[0111] File-open, find the global 900m DEM data file that comes with ENVI in the ENVI installation path, and open it:

[0112] Search for Compute Statistics in Tooxbox and double-click to open it;

[0113] Proceed as follows:

[0114] Click OK in Subset by File Input File, Select Statistic Subset, and ComputeStatistics Input File in turn. The parameters of the Compute Statistics panel are set as follows:

[0115] The statistical results are as follows:

[0116] Atmospheric Model: Atmospheric model, select the appropriate atmospheric model according to the table below

[0117] aerosol model: aerosol model, select urban or rural according to actual conditions;

[0118] Multispectral Settings: Multi-band settings:

[0119] For KT inversion, select the default mode: Defaults->Over-Land Retrieval standard (600:2100), which automatically selects the corresponding band and leaves other parameters as default.

[0120] (3) Cloud removal (cloud mask)

[0121] Cloud mask: extract the cloud-covered areas and exclude them from the calculation:

[0122] 1) Use the cloud mask file provided by UGCS for processing;

[0123] Operation: Open the downloaded mask image, Toolboxs—Feature Extraction—SegmentationImage, select the cloud mask file, and set the background value to 0;

[0124] Save the mask file: File—Save As—Save As, select multispectral data—Mask, select the cloud detection result as the mask file, select the corresponding output format and path, and click OK

[0125] The pixel values of the cloud areas in the obtained image will become nodata. When performing a fast atmospheric correction on this image, the pixels in the cloud areas will not participate in the calculation, improving the atmospheric correction or classification accuracy.

[0126] 2) The cloud automatic detection tool generates a cloud mask (only for Landsat8 sensors)

[0127] File—Open, open the multispectral data, thermal infrared data, and cirrus band;

[0128] Radiometric calibration: Toolbox–Radiometric Correction (radiation correction)–RadiometricCalibration (radiometric calibration);

[0129] Calibrate the multispectral data to the top-of-atmosphere apparent reflectance (TOA);

[0130] Calibrate the thermal infrared data (bands 10 / 11) to the brightness temperature;

[0131] Calibrate the cirrus band (band 9) to the top-of-atmosphere apparent reflectance TOA;

[0132] Toolbox—Feature Extraction—Calculate Cloud Mask Using FmaskAlgorithm;

[0133] Toolboxs—Feature Extraction—Segmentation Image, select the cloud mask file, and set the background value to 0;

[0134] Save the mask file: File—Save As—Save As, select multispectral data—Mask, select the cloud detection result as the mask file, select the corresponding output format and path, and click OK;

[0135] The pixel values of the cloud areas in the obtained image will become nodata. When performing a fast atmospheric correction on this image, the pixels in the cloud areas will not participate in the calculation, improving the atmospheric correction or classification accuracy.

[0136] (4) Image Fusion

[0137] Purpose: Resample a low-resolution multispectral image and a high-resolution single-band image to generate a high-resolution multispectral image, so that the processed image has both a high spatial resolution and multispectral characteristics.

[0138] Operation: Open the data to be fused from File—Open.

[0139] Toolbox—Image Sharpening—Gram-Schmidt Pan Sharpening. First, select the low-resolution multispectral image and click OK; then select the high-resolution single-band image and click OK.

[0140] In the parameter panel, select the sensor type according to the data. Here it is: Landsat8 oli; select the resampling method as needed. The common resampling methods are as follows; finally, set the output path and file name.

[0141] Resampling methods:

[0142] (5) Image Cropping

[0143] 1) Regular cropping

[0144] File—New—Region of Interest. In the ROI tool, select the geometric tool and define the range for cropping.

[0145] In the ROI toolbox, select File—Save As, set the output path and save;

[0146] In Toolbox, find Regions of Interest—Subset data from ROIs and double-click to open.

[0147] Select the image to be cropped—select ROI, set the output path—click OK.

[0148] 2) Irregular cropping—Cropping remote sensing images with vector data

[0149] Open the vector data and the remote sensing image to be cropped.

[0150] In Toolbox, find Regions of Interest—Subset data from ROIs and double-click to open.

[0151] Select the image to be cropped—select ROI, set the output path—click OK.

[0152] (6) Image Mosaic

[0153] 1) Open the remote sensing image to be mosaicked

[0154] Open the toolbox, find Mosaicking—Seamless Mosaic, and double-click to open the Seamless Mosaic control panel

[0155] Click the + sign in the Seamless Mosaic panel, click select all to select the data to be mosaicked, and click OK;

[0156] 2) Color equalization processing—Histogram matching:

[0157] In the Color Correction module of the Seamless Mosaic panel, select Histogram Matching

[0158] Overlap Area Only: Histogram matching in the overlap area

[0159] Entire Scene: Histogram matching for the entire scene image

[0160] 3) Set the transparency value

[0161] Set the transparency value in the Data Ignore Value list in the Main module of the Seamless Mosaic panel. This value can be set when there is a background value in the overlap area. Select Show Preview in the upper right corner to preview the mosaic effect

[0162] 4) Color Matching Action

[0163] In the Main module of the Seamless Mosaic panel, right-click on Color Matching Action, set Reference and Adjust, and determine the reference image according to the preview effect. Click Finish after setting

[0164] 5) Seam line and feathering

[0165] The seam line includes automatic drawing and manual drawing

[0166] In the Seaml ines drop-down list of the Seamless Mosaic panel, select Auto GenerateSeamlines to automatically draw the seam line and automatically crop the "jaggies" at the TM edge;

[0167] 6) Output the result

[0168] In the Export module of the Seamless Mosaic panel, click Finish after setting the parameters.

[0169] 7) Band composition

[0170] Toolbox—Raster Management—Layer Stacking, open the layer stacking panel

[0171] Click Reorder Files to sort the pictures according to the bands, and then click OK

[0172] Water body extraction

[0173] (1) View the water body spectral curve

[0174] Check if it relatively conforms to the water body reflection spectral curve

[0175] Such as Figure 2 shown:

[0176] (2) Calculate the water body index

[0177] Normalized Difference Water Index NDWI = (Green - Near Infrared) / (Green + Near Infrared);

[0178] Modified Normalized Difference Water Index MNDWI = (Green - Middle Infrared) / (Green + Middle Infrared);

[0179] Normalized Difference Vegetation Index NDVI = (Near Infrared - Red) / (Near Infrared + Red);

[0180] Inverse Normalized Difference Vegetation Index INDVI = (Red - Near Infrared) / (Red + Near Infrared);

[0181] Enhanced Vegetation Index EVI = 2.5×(Near Infrared - Red) / (Near Infrared + 6×Red - 7.5×Blue + 1)

[0182] Operation: Toolbox—Band Algebra—Band Math, double-click to open Band Math, and enter the calculation formula (the numbers should be floating-point type);

[0183] Such as Figure 3 shown, to obtain the water body index map:

[0184] [[ID=5 ]]Right-click on the data generated in the layer manager, open Quick Stats, and find that the result range is between -1 and 1, and extraction can be performed;

[0185] Calculate the threshold: Draw multiple ROIs to determine the water body extraction threshold

[0186] Operation: Right-click on the data and select New ROI; after drawing the polygon, right-click on the ROI and select Calculate to view the threshold;

[0187] Define multiple regions until a suitable threshold is selected.

[0188] Right-click on New Raster Color Slice, open the Edit Raster Color Slice table, and edit the threshold

[0189] (3) Export data

[0190] 1) Export as SHP format

[0191] Click Save - Save as Export as Class Imange to export the class image;

[0192] Export the water body as a vector: Toolbox Classification - post classification - classification to vector, select the just-generated binary result to obtain the EVF data for water area extraction

[0193] Convert EVF data to SHP:

[0194] Toolbar Vector - Classic EVF to Shapefile, import the EVF data and export as SHP

[0195] 2) Export as TIFF format

[0196] Click Save - Save as Export as Class Imange to export the class image;

[0197] Right-click on the generated color slice file and export as TIFF.

[0198] Example 3:

[0199] Method for demarcating the land buffer zone:

[0200] The land buffer zone is initially determined by extending outward from the river water level fluctuation area according to the on-site survey data such as the land use type and topography of the river bank zone, combined with the buffer zone classification method and definition in the Technical Guide for the Protection and Restoration of River and Lake Ecological Buffer Zones. The specific ranges of various ecological buffer zones are as follows:

[0201] Farmland-type ecological buffer zone:

[0202] Using the ASTER GDEM 30M resolution digital elevation data publicly available in the Geospatial Data Cloud of the Computer Network Information Center, Chinese Academy of Sciences, the elevation data of the river basin is converted into slope data using geographic software, and overlaid and analyzed with the distribution map of river buffer zone types to determine the slope of the area where the farmland-type ecological buffer zone is located. According to the slope of the buffer zone, the minimum width value of the terrestrial buffer zone recommended for different slopes in the "Technical Guide for the Protection and Restoration of River and Lake Ecological Buffer Zones" is used to determine the buffer zone range.

[0203] Village-type ecological buffer zone:

[0204] The determination method is the same as that of the farmland-type ecological buffer zone, except that the recommended width values in the "Guide" for different slopes vary.

[0205] Desert-type ecological buffer zone:

[0206] It is delimited according to the lowest value recommended in the "Technical Guide for the Protection and Restoration of River and Lake Ecological Buffer Zones", and the delimited range is 50m.

[0207] Calibration of the buffer zone range:

[0208] After initially delimiting the river buffer zone according to the widths of various terrestrial buffer zones recommended in the above-mentioned guide, through the method of visual screening, the areas where the buffer zone extends outward but still has a large gap with the river management scope line are filled manually; at the same time, the areas where the terrestrial buffer zone exceeds the river and lake management shoreline are compared with the land use type map. For the ecological buffer zones with the first-level land use types of wetland, forest land, grassland, and other land, they are retained. For the ecological buffer zones with the first-level land use types of cultivated land, plantation land, industrial and mining land, public management and public service land, special land, transportation land, and water conservancy facility land, they are adjusted manually, and the areas exceeding the river and lake management shoreline are adjusted to be flush with or inside the river and lake management shoreline. After the above adjustments, the final range of the river ecological buffer zone is determined.

[0209] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ecological buffer zone planning method, characterized in that, Including: Obtain remote sensing image data and hydrological data of the target river-lake area for determining the river-lake shore zone type and the range of the water level fluctuation zone; Based on the river-lake shore zone type and the range of the water level fluctuation zone, combined with slope data and land use type data, calculate the width of the land buffer zone and generate the preliminary buffer zone range; Calibrate the preliminary buffer zone range, and make manual adjustments in combination with the river-lake management shoreline and the land use type map to determine the final ecological buffer zone range.

2. The ecological buffer zone planning method according to claim 1, characterized in that The steps of obtaining remote sensing image data and hydrological data of the target river-lake area include: Import the remote sensing image data of the target river-lake area, and generate the preprocessed remote sensing image through radiometric calibration, atmospheric correction and cloud removal processing; Based on the preprocessed remote sensing image, use the water body index method to extract the historical highest water level line and the lowest water level line, and delimit the range of the water level fluctuation zone; According to the land use pattern and ecological degradation characteristics of the river-lake shore zone, classify the river-lake shore zone as an ecological protection type or an ecological restoration type.

3. The ecological buffer zone planning method according to claim 2, wherein The radiometric calibration includes converting the original DN value of the remote sensing image into the surface reflectance; The atmospheric correction uses the FLAASH model to eliminate the influence of aerosol and atmospheric scattering; The cloud removal processing eliminates the invalid data in the cloud-covered area through the cloud masking tool.

4. The ecological buffer zone planning method according to claim 2, wherein The water body index method uses the improved normalized difference water index, and extracts the water body boundary through threshold segmentation, and combines the remote sensing data of the past two decades to invert the historical water level line.

5. The ecological buffer zone planning method according to claim 4, characterized in that, The optimized formula of the improved normalized difference water index is: where ρgreen: the surface reflectance of the green light band; ρmid-infrared: the surface reflectance of the mid-infrared band.

6. The ecological buffer zone planning method according to claim 1, characterized in that The calculation method of the land buffer zone width includes: For the ecological protection type river-lake shore zone, delimit the buffer zone according to the vegetation cover type, desert or rock characteristics according to the preset width recommended value; For the ecological restoration type river-lake shore zone, determine the buffer zone width based on the slope interpolation method, empirical value method or model simulation method in combination with the agricultural non-point source pollution control target; For the composite river-lake shore zone, determine the buffer zone width according to the shore zone type with the highest area ratio.

7. The ecological buffer zone planning method according to claim 1, characterized in that, The slope interpolation method is: convert the ASTER GDEM digital elevation data into slope data, overlay it with the buffer zone type distribution map, and perform interpolation calculation according to the slope value and the preset width recommended table; The formula of the slope interpolation method is Buffer width = W 基准 + k·S where Wreference: the reference width when the slope is 0; S: the slope value, unit: degree; k: the slope adjustment coefficient, -0.5 for sandy soil, +0.5 for clay, and 0 for loam.

8. The ecological buffer zone planning method according to claim 1, characterized in that The determination of the final ecological buffer zone range includes: Compare the preliminary buffer zone range with the river-lake management shoreline, and manually fill the areas with gaps; Eliminate the areas that exceed the river-lake management shoreline and whose land use types are cultivated land and industrial and mining land, and retain the wetland, forest land and grassland areas to generate the final buffer zone range; If the river-lake management shoreline is not delimited for the target river reach, use the river bank zone ecosystem management model or the empirical value method to determine the buffer zone boundary.

9. The ecological buffer zone planning method according to claim 8, characterized in that, The formula of the river bank zone ecosystem management model is: where Q: annual average runoff, m 3 / s; C: the pollutant concentration, mg / L; R: the vegetation filtration efficiency coefficient; V: the surface runoff velocity, m / s; K: the soil adsorption coefficient.

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