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Sensors and Materials, Vol. 35, No. 3 (2023) 835–854
MYU Tokyo
S & M 3213

High-precision Ecological Protection Red Line
Boundary Optimization for Fangshan District, Beijing, China
Yi Zhang,1,2 Bogang Yang,1,2* Yu Liu,3
Shuang Wu,1,2 Yajun Cui,1,2 and Tianhao Xu1,2
1Beijing Institute of Surveying and Mapping, Beijing 100038, China

2Beijing Key Laboratory of Urban Spatial Information Engineering, Beijing 100038, China
3Real Estate Registration Office of Fengtai District, Beijing 100071, China(Received October 26, 2022; accepted March 8, 2023)

Keywords: ecological protection red line, boundary optimization check, high precision, clustering andgranulation, CART, complex data

In recent years, China’s resource and environmental problems have become increasingly
severe, and the pressure on resource constraints has continued to increase. The Chinese
government has delineated constraints for spatial planning based on the ecosystem, that is, a“red line for ecological protection”, which aims to “control the ecological space” and optimize
the ecological environment. The optimized verification of this red line can improve the accuracyof its boundary, ensure habitat integrity, and provide data and methods supporting the protectionof the ecosystem. In this study, the problems of verifying the boundary of the ecologicalprotection red line include five major categories and 24 minor categories, such as accuracy
problems, current situation problems, contradictions with planning, boundary consistency
problems, and integrity problems. Taking Fangshan District, Beijing, China, as an example,
based on the results of delineating the ecological protection red line in Fangshan District, we
integrated geographical monitoring, land use surveys, high-resolution remote sensing images,
small forestry classes, protected areas, road networks, water networks, and 14 types of multisource data, such as architectural and planning data. On the basis of the idea of clustering, we
granulated the types of plaques in the ecological protection red line into three categories, nature
reserves, river wetlands, and other protection units, and we assessed multi-source data regarding
the specific problems of various types of plaques in the ecological protection red line. We used
an adaptive design, using the big data processing mode of red line plaque fragmentation, basedon ArcGIS spatial data analysis and processing functions to optimize and verify the red line
boundary. We obtained a mapping accuracy of 1:10000 for the ecological protection red line,
which is a breakthrough in accuracy. This study provides a base map for ecological protection
via the red line management, supervision, and comprehensive implementation of land and spaceplanning. The research method is also applicable to research on optimizing the red line boundaryfor ecological protection in other regions of the country.
*Corresponding author: e-mail: bogangy@126.com

https://doi.org/10.18494/SAM4200

ISSN 0914-4935 © MYU K.K.
https://myukk.org/

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1.

Sensors and Materials, Vol. 35, No. 3 (2023)

Introduction

The ecological protection red line refers to an area that has special important ecological
functions within an ecological space and must be strictly protected. It is the bottom line andlifeline for ensuring and maintaining national ecological security.(1) The delineation of theecological protection red line is a strategic requirement of China, and it is an important measureused to promote China’s “five in one” strategic layout and the construction of an ecologicalcivilization.(2) Many scholars have studied the delineation, landing, and management of theecological protection red line across China. Other countries have also protected their ecologicalenvironments by delimiting ecological protection red line areas. For example, Japan has
designated 60% of its land area as ecological land.(3) The development of China’s ecologicalprotection red line used 2011 as the baseline and was divided into the budding and rapid
development periods.(4) In 2011, the State Council first proposed the strategy of protecting theecological environment by delimiting the ecological protection red line, which embodies China’s
determination to implement the most stringent ecological environmental protection strategy inhistory.(5) In 2015, the Chinese government launched the Delimitation and Protection of the
Ecological Protection Red Line policy, the purpose of which is to integrate all protected areas
into a unified and strict management system.(6–8)
Regarding the identification and delineation of the ecological protection red line, different
scholars have studied different areas and landforms. Wu used a large-scale regional division
method to study southwest China and divided the region into protected, construction, conflicted,
and low-pressure areas.(6) Xu et al. used three ecological models (InVEST, RUSLE, and CASA)
and five key indicators to establish a consistent framework and standards for the ecologicalprotection red line; additionally, they identified the ecological red line in the Yangtze River
Economic Belt.(10) The same group studied a blueprint of China’s ecological protection red line
and key indicators for measuring the line, spatial analysis and classification methods, andprotection policies.(11) Wang et al. evaluated the coastal and terrestrial ecosystems in Liaoning
and established protection and environmental pressure indicators to identify the ecological red
line in coastal areas of Liaoning Province, China.(12) Zhang et al. performed Geographical
Information System–based multi-criteria decision analysis (GIS-MCDA) with an indicatorsystem, indicator weights, and coverage rules to measure the degree of urban ecologicalvulnerability on the GIS platform.(13) Zhang et al. studied the conflicts among three land
management red lines (urban growth boundary, ecological protection red line, and basic
farmland protection area) using various statistical analysis methods, including spatial
autocorrelation, imaging gradients, and landscape pattern analysis, and researched the driving
forces of these conflicts.(14) Using Xiamen Bay as a research area, Hu et al. studied the methodof delineating the red line of coastal marine ecological protection and proposed a comprehensive
framework to establish an index system (including 26 indexes) for delineating the red line
region.(15)
Gao et al. summarized the theory and practice of delineating the ecological protection redline in China and proposed countermeasures and approaches to address the problems andchallenges faced by the ecological protection red line in the processes of delineation,

Sensors and Materials, Vol. 35, No. 3 (2023)

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management, and implementation.(16) Wang et al. assessed the ecological problems in the Qilian
Mountains and made proposals to promote the implementation of the ecological protection redline by accelerating comprehensive scientific investigations, improving and implementing theecological compensation mechanism, and exploring a coordinated development model oriented
by a positive list.(17) Zou et al. conducted a comparative analysis of the concept of the ecologicalprotection red line and the concept of red lines for other elements, and they proposedmanagement ideas and methods that can be used in the delineation of the ecological protection
red line to promote its final landing.(18) The progress and shortcomings of the relevant theories
and research methods related to the ecological red line have been assessed. In view of theshortcomings of the delineation method for the ecological protection red line, we propose a newdelineation method based on ecological security pattern theory, and we verify the operability ofthe method on a municipal scale.(19)In the field of identifying city and urban agglomeration, relevant studies have been conductedon the ecological protection red line.(20–22) Different regions have been studied, such as
Changchun,(22) Bohai Rim,(23) Qiqihar,(24) and Songnen. Li et al.(25) showed that the regional
economic development and the economic effects generated by export enterprises have a negative
impact on animals living in the red line area; however, a positive impact has been noted in somecases. The Yangtze River is the longest river in China, and the Yangtze River Economic Belt has
an impact on the Chinese economy. Because of its importance, research has been performed on
the Yangtze River’s ecological protection red line.
Research on the ecological protection red line has mostly focused on the delineation method,
theoretical research, and management policy research of the line; there have been few studies on
the accuracy problems, the boundary optimization check, and the landing of the ecologicalprotection red line boundary. This study was based on the ArcGIS platform and used highresolution remote sensing image data and geographic and national condition monitoring andother multi-source basic data. Additionally, on the basis of the grading and classification of theecological protection red line boundary check optimization in Beijing, the boundary accuracy ofthe ecological protection data itself is optimized. Figure 1 provides the research workflow used
to generate the most basic data baseline map for the ecological protection red line.

2.

Study Area

Fangshan District is located in the southwestern part of Beijing, China (39°30’–39°55’N,
115°25’–116°15’E). The southwest gateway of Beijing, with an area of approximately 2019 km2,
has a high elevation in the mountainous northwest (two-thirds of the total area) and a low
elevation in the plains in the southeast. Fangshan District is an ecological barrier area with asuperior ecological environment including Fangshan Geological Park, the oldest primary
secondary forest in North China National Forest Park; the largest karst cave group in northern
China; Shihua Cave; Yinhu Cave; and the Shidu Scenic Area. Yongding River passes throughthe urban area, forming a green spatial structure in which the mountains and rivers areintertwined. Fangshan District has rich biodiversity, a complex natural environment, a complex
ecological structure, and a variety of geological landforms. The height difference between the838

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Fig. 1.

(Color online) Workflow of ecological protection red line boundary optimization check.

mountainous areas and plains is large, resulting in a large variation in climate. The study area isshown in Fig. 2.
The area of the Fangshan ecological protection red line is approximately 627.13 km2, and theperimeter is approximately 3480.28 km, accounting for 14.62% of the total area of Beijing’s
ecological protection red line and 31.43% of the area of Fangshan District. It mainly includes themountainous areas in the northwest and the areas along the Juma River, Yongding River, and theSouth-to-North Water Transfer Project. These areas include important river wetlands and waterand soil conservation areas (e.g., Juma River, Yongding River, and South-to-North Water
Diversion, with an area approximately 34.58 km2), and areas responsible for maintaining
biodiversity and other important ecological functions (China Fangshan Geological Park, Shidu
Scenic Area, and Shihuadong Landscape Scenic Area, with an area of approximately
592.55 km2). The red line of the ecological protection boundary in Fangshan District is extremely
irregular and has jagged borders, and the habitat integrity is poor.

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Fig. 2. (Color online) Overview of ecological protection red line in the study area: (a) China, (b) Beijing, (c)Fangshan, (d) Fangshan remote sensing image, (e) Fangshan ecological protection red line (before checking).

3.

Materials and Methods

3.1

Integration and preprocessing of multi-source data

Checking the boundary of the ecological protection red line is a labor-intensive task withhigh complexity and strict requirements. According to the requirements of China and Beijing,when changing the ecological protection red line, sufficient proof must be provided to justify
each change. The ecological protection red line involves different ecological elements, such as
mountains, forests, fields, lakes, and grasses, most of which involve protection units, such as
nature reserves, forest parks, and scenic spots. However, other elements may not include
protection units. The red line patch elements must be supported by reference data with clear
geographic boundaries when they are checked. Therefore, the timely and comprehensive
collection of multi-source data is the basis for verifying the ecological protection red line
boundary. At the same time, owing to differences in data format, mathematical projection basis,and the reliability of data type, it is necessary to carry out data analysis and unify the referencebasis.
The basic reference data of the ecological protection red line boundary check include highresolution remote sensing image, geographic national condition monitoring, large-scale
topographic map, and secondary land and resource survey data. This study combines the typesof plots included in the Fangshan ecological protection red line and the reference data collected
to meet the basic data requirements while additionally including data on nature reserves, various

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types of protection units, and single building data. Owing to the lack of data, these materials
have provided strong support and protection in improving the efficiency of the work on verifying
the ecological protection red line border, improving the accuracy of the results, and ensuring theaccurate landing of the red line.
With the support of the Beijing Municipal Bureau of Ecology and Environment, the Beijing
Academy of Environmental Sciences, and the Beijing Municipal Planning and Nature
Commission groups of various districts, combined with the data already available, a total of 14
types of main reference data were collected as shown in Table 1. The analysis of the data and theprocessing of the multi-source data mainly involve the transformation and unification of the data
coordinate system. According to the requirements of technical documents such as Guidelines forthe Delineation of the Ecological Protection Red Line and Technical Regulations for Defining
Standards of Ecological Protection Red Line Surveys, the coordinate system should adopt the2000 National Geodetic Coordinate System (CGCS2000). The coordinate conversion in thisstudy used transProXY software (http://transproxy.sourceforge.net/). This software can convert
between the Beijing local coordinate system and the 2000 Chinese national local coordinate
system, and the accuracy of coordinate conversion meets the requirements of this research. We
converted the above 14 types of data using transProXY software and imported the data into
ArcGIS 10.1 (https://www.arcgis.com/index.html). All data were successfully imported andprocessed.
3.2

Ecological protection red line plaques based on clustering granulation

The ecological protection red line itself has complex data, and this complexity is reflected in
the complexity of data patches and data problems. The modeling of complex data is the basis ofdata analysis and utilization, and the modeling mainly includes classification, regression,clustering, and decision-making. In the processing and modeling of complex data, the cognitive
mechanism plays an important role. A well-known cybernetic expert in the United States noted
the problem of the granulation of fuzzy information. He summarized the human cognitive
ability as granulation (the whole is decomposed into parts), the three main characteristics oforganization (parts integrated into a whole), and cause and effect (causal association).
Information granulation is a process of granulating complex data into information granules
through a given granulation strategy.
The patches contained in the ecological protection red line data have a variety of descriptions
and coexistence phenomena. One red line patch belongs to nature reserves and forest parks, aswell as scenic spots, and the boundaries of the three data forms cross each other. To ensure theaccuracy of the ecological protection red line boundary check and the integrity of the habitat, on
the basis of the idea of data granulation, the plaque types within the ecological protection redline were granulated into three categories: nature reserves, river wetlands, and other protection
units.

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Table 1
Types and descriptions of multi-source data.
SerialType of data
Description of data
numberVarious nature reserves 21 nature reserves in Beijing with legal borders (including core areas, buffer
1.
in Beijingzones, and experimental area boundaries).
Mainly include protection units with clear boundaries, such as forest parks,
2.
Various protected areas geological parks, scenic spots, wetland parks, world natural heritage sites,and drinking water sources.
Reflects natural attributes or conditions of natural and artificial structureson surface of land, mainly including planted land, forest, and grass cover;housing construction, railways, and roads (road cover classifications
3.
Ground coverother than railways are unified as roads, regardless of category or level);structures, artificially dug, deserted, and bare land; and water areas of eight
first-class categories.
Collected in the form of geographic entities. Data includes the types,
grades, and locations of roads and reflects structural characteristics, traffic
conditions, distribution density, and relationships with other elements ofroad network. Mainly includes railways, highways (national, provincial,
4.
Road networkcounty, rural, and special roads and connecting roads between highways),urban roads (main roads, expressways, branch roads, etc.), rural roads, andramps.
Permanent places with roof and surrounding walls that can protect against
wind and rain for people to work, live, study, entertain, and store supplies.
Have fixed foundations occupying land space and generally have height of5.
Stand-alone buildings
2.2 m or more. Data attributes mainly include information about districts andcounties, nature of land, nature of building, area of building, and number offloors above ground.
High-resolution remote
Latest city-wide image data with resolution of 1 m. This study uses images
6.
sensing images
from third quarter of 2019.
Forestry resources survey Latest forestry resources survey results provided by Beijing Municipal
7.
subclass data
Bureau of Landscaping and Greening.
Planted commercial
Data with attribute “artificial commercial forest” extracted from forestry
8.
forestresource survey subclass data.
Land resources survey
9.
Including secondary tone data, land change survey data.
data
Large-scale topographic 1:5000 topographic map of Beijing city, 1:2000 topographic map of plain
10.
map
area, 1:500 topographic map of central city area.
Newly approved river protection scope provided by planning or water affairs
11.
River blue line
department, mainly includes five major rivers in Beijing (North Canal,
Yongding River, Chaobai River, Wenyu River, and Luan River).
Permanent protection
12.
of farmland delineation Latest approval data provided by planning department.
results
Town development
13.
Latest approval data provided by planning department.
border14.
Partition planning data
Latest approval data provided by planning department

3.3

Application technology model based on classification and regression tree (CART)
model

To promote the ecological protection red line to be set and landed, with the service ofBeijing’s ecological civilization construction as the core and the service of national land spatial

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planning as the guide, this study combines the actual situation of the Beijing ecologicalprotection red line, innovatively categorizes and classifies the content of the Beijing red line
border check, and formulates a fine-grained classification index system for content in the Beijing
ecological protection red line border check, which greatly facilitates the accurate placement andimplementation of the Beijing red line to support the smooth development of ecologicalprotection policies in Fangshan District.
By combining the high-resolution remote sensing image data, the monitoring data ofgeographic national conditions, nature reserve data, and other special materials, we analyzed thedelineation results of the Fangshan ecological protection red line in ArcGIS. On the basis of
meeting the national requirements and combining the actual situation of the ecological protection
red line in Beijing, the types of red lines that must be optimized are summarized and further
classified. In this study, the types of ecological protection red line patches in Beijing to be
optimized were divided into five first-level categories and 24 second-level categories, which are
shown in Table 2.
3.4

Construction of the boundary check index system

The comprehensive application of multi-source data integrates various data to absorb thecharacteristics of different data sources and then extracts better and richer information than that

Table 2
Hierarchical classification of ecological protection red line patches in Beijing.
Check typeSpecific reason
Red lines cut boundaries of construction land (houses, roads, etc.)
Overall shift of plaque position
Boundary fine-tuning
Accuracy exceeded
Unreasonable holes
Topological issues (topological errors such as face overlaps, facestabs, and minimal faces)
Massive settlements within red line
Red line contains high-grade roads (roads above provincial level)
Railways included in red line
Contradiction with status quo construction Expressways in red line
Main roads included in red line
Red line conflicts with land use status
Status quo construction unsuitable for inclusion in red line
Zoning planning
Special planning
Conflict with planning
Urban development boundary
Permanent basic farmland
Major planning and construction projects
Data edge
Consistent with administrative boundaries
Supplement to boundary
Connectivity adjustment
Remove broken plaques
Preserving habitat integrity
Connect with natural boundaries
Linking boundaries of various protected areas

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843

available using single data. The analytical classification of feature data currently uses theclassification regression tree (CART) model. In this study, a CART model for entity objects wasdeveloped. Each type of ecological protection red line plaque was taken as the research object.
The data types used in the verification process were divided into two parts, Yes and No, where
the left branch has the value “Yes” and the right branch has the value “No”. The regression
number model is as follows.
Suppose that X and Y are the input and output vectors, respectively, Y is a continuous variable,
and D is the training dataset=D{( x , y ) , ( x , y ) , ( x , y )……( x , y )} .
1

1

2

2

3

3

N

N

(1)

A regression tree corresponds to a partition of the input space (i.e., eigenvalues) and theoutput values on the partitioned units. Assuming that the input space has been divided into M
units, i.e., R1, R2, ..., R M, and there is a fixed output value (cm) on each unit (Rm), the regression
tree model can be expressed as=f ( x)

M∑c I ( x ∈ R ) .
m =1

m

m

(2)

By combining the characteristics of this ecological protection red line boundary check andthe characteristics of Beijing’s ecological protection red line, the mountain, forest, lake, andgrass categories in the red line are divided into three types according to the functional unit:
natural protection, river wetlands, and other protection units. The CART model used for thecomprehensive application of multi-source data for each type is shown in Fig. 3.
3.5

Compilation of check plot description

The boundary check of the ecological protection red line is a key step to ensure the accurate
landing of the red line. This study is based on ArcGIS software, which has powerful spatial data
analysis and spatial data processing capabilities, with each red line patch as the object. On thebasis of the general principles of no reduction in area, no change in spatial layout, and no change
in the nature of land use, according to the requirements of integrity, accurate landing, andorderly connection, the characteristics of the red line plaques and the type of verification
required are analyzed; furthermore, with reference to the data, each change in the patch in the
red line boundary check is recorded and explained in detail.

4.

Results and Analysis

4.1

Calibration results of ecological protection red line boundary

During data processing, we followed the principles of maintaining habitat integrity, accurate
landing, and orderly connection, allowing us to effectively process the data. Five types ofproblems were found in the ecological protection red line boundary check: accuracy problems,

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(a)

(b)
Fig. 3. CART model for comprehensive application of multi-source data: (a) CART model of red line involving
nature reserves. (b) CART model of red line involving river wetlands.

Sensors and Materials, Vol. 35, No. 3 (2023)

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(c)
Fig. 3. (Continued) CART model for comprehensive application of multi-source data: (c) CART model of red line
involving other protection units.

current situation issues, contradictions with planning, boundary consistency issues, and integrity
issues. We optimized the verification model according to the plaque fragmentation of big data
and dealt with the above problems. The red line distributions before and after the treatment are
respectively shown in Figs. 4(a) and 4(b).
The plaques adjusted during the calibration process are divided into two types:“supplemented” and “reduced”. The plaques that are added and reduced are overrun according toaccuracy, contradiction with the current situation, contradiction with the planning, andconsistency with the administrative boundary. The five complete categories of habitats areclassified to explain the reason and basis of verification, involving a total of 11113 plaqueadjustments. Before the check, the area encompassed by the red line was approximately 627.13
km2, while after the check, it was approximately 630.13 km2, an increase of approximately 3.00
km2. There were four types of reduced plaques, those caused by habitat integrity, precision
overrun, contradictions with planning, and current status construction, and there were 6107
reduced plaques, with a reduction in area of approximately 14.64 km2. Supplemented plaques
were related to maintaining habitat integrity, exceeding accuracy limits, remaining within
administrative boundaries, and three other reasons, involving a total of 5006 plaque adjustments,
with an increase in area of approximately 17.64 km2.

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(a)

(b)
Fig. 4. (Color online) (a) Results of the red line boundary check study of ecological protection in Fangshan
District, Beijing before the check. (b) Results of the red line boundary check study of ecological protection in
Fangshan District, Beijing after the check.

4.2

List of land parcels for ecological protection red line check in Fangshan District

Reduced land parcels: Among the 6107 plaque reductions, the habitat integrity category had
approximately 191 plaques with an area of approximately 0.34 km2, the exceeded accuracy

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847

category had approximately 5500 plaques with an area of approximately 12.09 km2, and theplanning contradiction category had approximately 115 plaques with an area of approximately
0.88 km2. There were 301 contradictory constructions with an area of approximately 1.33 km2.
Figure 5 shows the increases and reductions of the plots of the Fangshan ecological protection
red line area, and the statistics of plaques with an area greater than 0.01 km2 are shown in Table
3.
Description of supplemented plots: Before and after checking the red line of ecologicalprotection in Fangshan District, the red line was adjusted. There were three types ofsupplemented plots involving 5006 sites, with a total increase in area of 17.64 km2. Amongthem, there were approximately 143 habitats with a total area of approximately 0.50 km2,
approximately 4821 sites in the over-accuracy category with an area of approximately 17.05 km2,
and 42 sites that were consistent with the administrative boundary with an area of approximately
0.09 km2. Statistics of plaques with an area greater than 0.01 km2 are shown in Table 4.
4.3

Boundary check of ecological protection red line and preparation of check plot
description

Figures 5(a) and 5(b) show that, at the scale of 1:220000, the difference between the overall
ecological protection red line in Fangshan District before and after the boundary check is not
obvious. The areas of the added and deleted plots are greater than 0.01 km2 and less than 0.2
km2, respectively. Therefore, we used a chart comparing the map before and after the specificaddition and deletion of borders to show the effect of using the ecological protection red line
border verification workflow. We solved all five types of problems mentioned in Sect. 1.

Fig. 5.
area.

(Color online) Increases and decreases of the red line check plots of Fangshan ecological protection red line

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Table 3
Description of reduced plots (plaques larger than 0.01 km 2).
SerialnumberUniquecode

Type ofcheck
Maintainhabitatintegrity1.

FS_ 2721

2.

FS_ 8

Accuracy
exceeded3.

FS_ 1675

Accuracy
exceeded4.

FS_ 2121

Accuracy
exceeded5.

FS_ 3341

Accuracy
exceeded

6.

FS_
5900

Contradicts
plan

7.

FS_ 5932

Contradicts
plan

8.

FS_ 5987

Contradicts
plan

9.

FS_
6008

Contradicts
plan

10.

FS_
5946

Contradicts
status quo

11.

FS_
5954

Contradicts
status quo

⁞

⁞

⁞

Specific reason

Verification basis

Explanation

Area
(km²)

Perimeter(km)

Eliminate broken
patches

Remove broken
patches—

0.03221.2013—0.02480.92340.01240.81480.012

1.03550.0176

3.30410.02390.78980.02010.92140.10443.77730.07753.07

0.03391.59830.02391.2252⁞
6.6622⁞318.4055

TopologicalRemote sensing image
problems
data(serrated borders)

Including
Red line cutting
Remote sensing image
urban
construction land
data/planning
construction
boundary (house)
land
TopologicalRemote sensing image
problems (surface—
data
breaks)GeographicalRed line cutting
conditions monitoring—boundary of
data, remote sensing
construction land
imagesIncluding
Yanshan Base Core
urban
District EasternSpecial planning
construction
District Control
land
Regulations
Planning of
employment
base forPlanning project
Lanning project
farmers inapproval scope
western
China
Overlapswith urban
Townshipconstructionlevel planning—land in townshipachievements inplanning results
Fangshan Districtof Fangshan
DistrictPlanning
Urban
achievements ofconstruction—
Fangshan branch ofland/village
construction land Beijing municipality
Red line contains
Remote sensing image
large-scale—
data
settlements
Red line contains
Remote sensing image
large-scale—
data
settlements
⁞
⁞
⁞
Total

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Table 4
Description of supplemented plots (plaques larger than 0.01 km 2).
SerialnumberUniquecode1.

FS_ 61742.

FS_ 7979

3.

FS_ 9059

4.

FS_ 11042

5.

FS_ 11106

6.

FS_ 11111

7.

Type of check
Maintainhabitatintegrity
Maintainhabitatintegrity
Maintainhabitatintegrity
Maintainhabitatintegrity
Maintainhabitatintegrity

Maintainhabitatintegrity
Consistent
with
FS_ 6120administrative
boundaries

Specific reason

Bridging boundaries
Bridging boundaries
of various protectedof basic farmland
areas

Explanation

Area
(km²)

Perimeter(km)—0.0151

0.9634

Connectivity
adjustment

Remote sensing
image data—

0.01361.5339Bridging natural
boundaries

Remote sensing
image data

—

0.018

0.7677

Connectivity
adjustment

Convergence of
nature reserves—

0.06081.355

Bridging boundaries
of nature reserves

Juma River
municipal aquatic
wildlife nature
reserve—0.0206

0.6788Connectivity
adjustment

Remote sensing
image data—

0.14123.385

Add to side

Supplement basedon administrative
boundaries—

0.03752.7184Fill holes basedon remote sensing
image data—

0.02240.8724

Remote sensing
image data—

0.03170.8376—0.01210.6371—0.0196

1.3433⁞⁞9.8588⁞425.9013

8.

FS_ 6108

Accuracy
exceeded

Unreasonable holes9.

FS_ 6110

Accuracy
exceeded

Topologicalproblems (serrated
borders)10.

FS_ 6111

Accuracy
exceeded

Unreasonable holes11.

FS_ 11058⁞⁞

Accuracy
exceeded⁞

Verification basis

Jagged border⁞
Total

Fill holes basedon remote sensing
image data
Remote sensing
image data⁞(1) Accuracy check: Make full use of the collected relevant data, check the accuracy of the redline boundary, and refine the boundary space data. The accuracy is not less than 1:10000.
Figure 6 shows a comparison of the red line before and after the check.
(2) Current check: Check the large-scale settlements, high-level linear infrastructures, and otherplots that contradict the status quo and are not suitable for inclusion in the red line. A
comparison of charts before and after calibration is shown in Fig. 7.
(3) Consistency check with the plan: The boundary check of the ecological protection red line
should be fully connected with zoning planning, special planning, and major planning andconstruction projects, and we coordinated the relationship between the three control lines.

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(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)

(l)

Fig. 6. (Color online) Examples of accuracy check results: (a) Before the topology error was checked. (b) After the
topology error was checked. (c) Before the topology error was checked. (d) After the topology error was checked. (e)Before the unreasonable hole was checked. (f) After the unreasonable hole was checked. (g) Before the topology
error was checked. (h) After the topology error was checked. (i) Before the red line border overlaying the road waschecked. (j) After the red line border overlaying the road was checked. (k) Before the topology error was checked. (l)After the topology error was checked.

(a)

(b)

(c)

(d)

Fig. 7. (Color online) (a) Before the large-scale settlement included in the red line was checked. (b) After the largescale settlement included in the red line was checked. (c) Before the high-level road included in the red line waschecked. (d) After the high-level road included in the red line was checked.

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The contradiction between the permanent basic farmland and the urban development
boundary should be checked to ensure that the three control lines do not cross or overlap. A
comparison of charts showing the results obtained before and after calibration is shown in
Fig. 8.
(4) Boundary consistency check: Check and adjust the fine and independent patches caused by
the plaques of adjacent areas being drawn into the boundary of the administrative area toensure the unity and consistency of the red line boundary and the line delimiting theadministrative area. A comparison of the charts before and after calibration is shown in
Fig. 9.
(5) Integrity check: According to the needs of the construction of the ecological security pattern,
we comprehensively consider the integrity of the regional or river basin ecosystem, and check

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

Fig. 8. (Color online) (a) Before construction land check in zoning plan in red line. (b) After construction land
check in zoning plan in red line. (c), (e) Before conflict between red line and urban development boundary waschecked. (d), (f) After conflict between red line and urban development boundary was checked

(a)

(b)

(c)

(d)

Fig. 9. (Color online) (a) Before the administrative boundary was checked. (b) After the administrative boundary
was checked. (c) Before the administrative boundary was checked. (d) After the administrative boundary waschecked.

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(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

Fig. 10. (Color online) (a) Before integrity check of continuous river without interruption. (b) After integrity checkof continuous river without interruption. (c) Before integrity check of river cut by viaduct. (d) After integrity checkof river cut by viaduct. (e) Irregular border check to ensure complete habitat check. (f) Irregular border check toensure complete habitat check. (g) Before removal of the broken pattern spot was checked. (h) After removal of thebroken pattern spot was checked.

the red line boundary based on the natural boundaries of terrain, landforms, vegetation, andriver systems as shown in Fig. 10.

5.

Conclusions

The implementation of the Beijing Ecological Protection Red Line has promoted thedevelopment of “rules” and “borders” in economic and social development and helped resolve
contradictions in socio-economic development planning, zoning planning, special planning,
environmental protection planning, and other industrial development planning conflicts. To
ensure the precise landing of the ecological protection red line in Beijing, the city has carried out
border checks, which are complex and tedious tasks.
Aiming at solving the problems of the low accuracy of the red line boundary and the few
boundary optimization check methods available in current ecological protection red line
research, an ecological protection red line boundary check workflow, including data collection
and preprocessing, based on clustering and granulation ideas was proposed, red line plaques
were granulated, and a boundary check index system was constructed using the CART modeland the method of checking the preparation of the plot description. This study further integrated
the multi-source data in accordance with the delineation requirements of “a red line governing
the ecological space” and innovatively graded and classified the contents of red line boundary
checks.

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The supplemented and reduced plaques were classified into five categories according toaccuracy overruns, contradictions with current construction, contradictions with planning,
consistency with administrative boundaries, and the maintenance of habitat integrity. A total of
11113 plaques were involved. The content of the audit was divided into five categories and 24
minor categories, including precision check, current check, coordinated check with the plan,boundary check, and integrity check, and corresponded to the “mountain, forest, field, lake, andgrass” organic ecosystem. The different elements in the study were based on the “element data”
and “problem solution basis” models for targeted border checks. This study will promote theconstruction of a world-class harmonious and livable capital in Beijing and the creation of abeautiful area around Beijing and will improve the land and space planning base map.

Acknowledgments
This research was supported by Beijing Key Laboratory of Urban Spatial Information
Engineering (No. 2019101). The authors would like to thank the reviewers and editors for theirvaluable comments and suggestions.

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About the Authors
Yi Zhang received her B.S. degree from Wuhan University in 2015 and her
M.S. degree from China University of Geosciences (Beijing) in 2018. Her
research interest covers the application of surveying and mapping geographic
big data. (1113611326@qq.com)

		Bogang Yang received his Ph.D. degree from Beijing Forestry University,
China, in 2006 and was engaged in postdoctoral work at Peking University
from 2007 to 2009. Since 1983, he has been working at Beijing Institute ofSurveying and Mapping, and since 2004, he has been a professor-level senior
engineer. He is the director of Beijing Key Laboratory of Urban Spatial
Information Engineering. His research interests are in surveying and mapping
technologies, smart city construction, and urban spatial analysis.
(bogangy@126.com)
Yu Liu received his B.S. and M.S. degrees from China University ofGeosciences (Beijing) in 2016 and 2019, respectively. His research interests
cover the policy and application of real estate registration. (921368971@qq.com)

		Shuang Wu received her B.S. and M.S. degrees from Harbin Normal
University, China, in 2011 and 2014, respectively. She received her Ph.D.
degree from Beijing Normal University, China, in 2021. Since 2021, she has
been working at Beijing Institute of Surveying and Mapping. Her researchinterests are in urban spatial analysis, climate change, and sensors.
(Shuang_1988@hotmail.com)
Yajun Cui received her B.S. degree from Shandong University of Science andTechnology in 2016 and her M.S. degree from China University of Mining &Technology, Beijing in 2019. Since 2019, she has been a technician at Beijing
Institute of Surveying and Mapping. Her research interests are in datainterpretation and utilization. (cuiyajun9@163.com)

Tianhao Xu received his B.S. degree from Beijing University of Posts andTelecommunications in 2019. His research interests cover survey andmonitoring data application services. (627209472@qq.com)