In recent years, due to the rapid development of social economy and population growth, the pressure of social activities on the environment has been increasing, and the contradiction between man and land has intensified. Although countries around the world have made many achievements in the construction and protection of the ecological environment, they have not fundamentally changed the trend of deterioration of the ecological environment; Instead of being slowed down, it has increasingly become a threat to regional development, social harmony, and national security. The issue of ecological environment security has become a strategic issue of great concern to all countries. In 2001, my country also incorporated ecological environment security into the scope of national security; the report of the 18th National Congress of the Communist Party of China pointed out that the construction of ecological civilization must be placed in a prominent position to build an ecological security pattern and build a beautiful China. In 2015, the national "Thirteenth Five-Year Plan" clearly pointed out that efforts should be made to improve the ecological environment and adhere to green development. According to the "National Land Planning Outline (2016-2030)", it is necessary to save and intensively use land resources, fully consider ecological security and resource and environmental carrying capacity in the process of land development and utilization, optimize the pattern of land space development, and promote the coordination of human-land relations develop. The "Proposals of the Central Committee of the Communist Party of China on Formulating the Fourteenth Five-Year Plan for National Economic and Social Development and the Long-term Goals for 2035" requires promoting green development and promoting the harmonious coexistence of man and nature. Adhere to the concept of "lucid waters and lush mountains are golden mountains and silver mountains", adhere to respecting nature, conforming to nature, and protecting nature, insisting on giving priority to conservation, protection, and natural restoration, and guarding the boundaries of natural ecological security. However, how to ensure regional ecological security in the development process is a key issue to be solved urgently, and the ecological security pattern provides an important spatial approach.
Ecological security refers to the health and integrity of ecosystems. The connotation of ecological security can be summarized as follows: first, to maintain the vitality of the ecosystem and the stability and sustainability of internal and external components and structures; second, to maintain the integrity of the ecological functions of the ecosystem; resistance. These three aspects are actually ecosystem health, service function and risk issues. The current construction index research is still in the stage of continuous exploration and improvement. Models and methods emerge in an endless stream. The construction method has changed from simple hierarchical analysis and suitability analysis to complex dynamic simulation of ecological processes. The research framework of "Tao Extraction" is a typical paradigm for constructing an ecological security pattern.
ArcGIS Pro, as ESRI's GIS product for the new era, inherits the powerful data management, mapping, and spatial analysis capabilities of the traditional desktop software (ArcMap) on the original ArcGIS platform, and also has its unique features, such as two 3D fusion, big data, vector slice production and release, task workflow, super-forced map, space-time cube, etc. Due to the simplicity, readability and scalability of the Python language, using Python will greatly improve the efficiency of geographic data processing.
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Chapter 1: Introduction to Ecological Security Evaluation Theory and Methods
1. Introduction to Ecological Security Evaluation
2. Introduction to Ecological Service Capabilities
3. Brief introduction to the research method of ecological security pattern construction
Chapter Two, Platform Basics
1. Introduction to ArcGIS Pro
1. Introduction to ArcGIS Pro
2. ArcGIS Pro Basics
3. ArcGIS Pro data editing
4. ArcGIS Pro Spatial Analysis
5. Model Builder
6. ArcGIS Pro symbol making
7. ArcGIS Pro mapping layout and drawing
Two, Python environment configuration
1. Python software download and installation
2. Program writing and running
3. Python code writing rules
4. File reading and writing
File object, reading and writing of text files, reading and writing of JSON files, reading and writing of binary files, reading and writing of HDF files, reading and writing of Excel files, file system and path operation
5. Introduction to ArcPy
basic situation
Running tools with ArcPy
Tool operating environment
spatial reference
6. Access and manage spatial data
Access and management of tabular data (table), feature class (feature class), raster data (raster), and dataset (dataset)
Chapter Three, Data Acquisition and Cleaning
1. Data acquisition:
The data mainly includes land use data, socioeconomic data, basic geographic information data, and natural environment data (topography, soil, and climate data):
2. Data preprocessing (ArcGIS Pro and Python environment)
1. Splicing, cropping, and reprojection of land use data (desktop and cloud computing)
2. Cutting, reprojection and resampling of socioeconomic data and vegetation index data (desktop and cloud computing)
3. Splicing and projection conversion of basic geographic information data, and rasterization of vector data
4. Meteorological data clipping, reprojection and resampling processing; site data extraction and geostatistical analysis
5. DEM data projection transformation and image cropping
Data cleaning: operations such as removing duplicate data, filling missing values, handling outliers, and converting data formats
Chapter 4 , Soil Erosion Evaluation Based on USLE Model
1. Introduction to the Technical Specifications for Ecosystem Service Function Assessment
2. The content and process, evaluation index system, evaluation method, etc. of ecosystem service function evaluation
Soil and water conservation functions are mainly related to climate, soil, topography and vegetation, and factors such as soil erodibility, topography, and rainfall are mainly considered.
The formula for calculating the Universal Soil Loss Equation (USLE) is as follows:
A=R*K*L*S*（1-C）
In the formula:
A: The annual average soil loss per unit area of any sloping cultivated land under the specific rainfall, crop management system and adopted soil and water conservation measures, t/ha
R: Rainfall erosivity factor, which is the unit rainfall erosion index. If the snowmelt runoff is significant, the snowmelt factor needs to be increased, MJ*mm/(ha*h)
K: Soil erodibility factor, the soil loss rate of the unit rainfall erosion index on the standard plot
L: slope length factor;
S: Slope factor, which is equal to the ratio of soil loss between the actual slope and 9% slope when other conditions are the same; since L and S factors often affect soil loss, LS is called terrain factor to show its comprehensive effect;
C: Vegetation coverage and management factor, equal to the ratio of soil loss on a specific vegetation and management plot to the soil loss of a standard plot when other conditions are the same;
Chapter 5. Evaluation of Windbreak and Sand Fixation Function Based on Wind Erosion Modification Model
Windbreak and sand fixation is the role of ecosystems (such as forests, grasslands, etc.) in reducing soil erosion caused by wind erosion through their structures and processes, and is one of the important regulating services provided by ecosystems. The function of windbreak and sand fixation is closely related to factors such as wind speed, rainfall, temperature, soil, topography and vegetation. The windbreak and sand fixation amount (the difference between the potential wind erosion amount and the actual wind erosion amount) is used as the evaluation index of the windbreak and sand fixation function of the ecosystem.
In the formula: SR is the amount of sand fixation (t km-2 a-1); SL potential is the potential wind erosion amount (t km-2 a-1); SL is the actual wind erosion amount (t km-2 a-1); QMAX is The maximum transfer amount (kg/m); Z is the maximum wind erosion distance (m), which is set to 50m in this experiment; WF is the climate factor (kg/m); K' is the surface roughness factor; EF is the erodible soil factor; SCF is soil crust factor; C is vegetation cover factor.
Chapter 6, Water Conservation Model
Water conservation is the interaction between ecosystems (such as forests, grasslands, etc.) Replenish groundwater, slow down seasonal fluctuations in river flow, detain floods and make up dry water, and ensure water quality. The water conservation capacity is used as the evaluation index of ecosystem water conservation function.
The model evaluation method is used to evaluate the water conservation evaluation model, and the water balance equation is used to calculate the water conservation amount. The formula of the water conservation evaluation model is:
In the formula: TQ is the total water conservation (m 3 ), Pi is the rainfall (mm), Ri is the surface runoff (mm), ETi is the evapotranspiration (mm), and Ai is the area of the i-type ecosystem (km2) , i is the type i ecosystem type in the study area, and j is the number of ecosystem types in the study area.
Chapter 7, InVEST Model Estimation of Carbon Stock and Habitat Quality
1. Carbon stock estimation
In the InVEST model, the carbon storage ( ) of the ecosystem is composed of four basic carbon pools: aboveground carbon storage ( ), underground carbon storage ( ), soil carbon storage ( ) and dead organic carbon storage ( ). The calculation formula of the model is:
Determining the carbon density value of each carbon pool is the key to calculating the carbon storage function of the ecosystem, and the carbon density is corrected by reference to literature or measured data.
2. Estimation of Habitat Quality
The value range of habitat quality is between 0 and 1, and the score reflects the quality of habitat, and plots with low scores are more likely to be destroyed.
Among them, denotes the habitat quality score of grid x in land use type j; denotes habitat suitability; K is the half-saturation parameter.
Chapter VIII. Construction of Ecological Security Pattern
1. Identification of important ecological sources
1. The importance of ecosystem services
Each ecosystem service is divided into five levels according to the natural breakpoint method: high, high, medium, low, and low. Based on the composition of the proportion of each ecosystem service in the ecological assets in the global ecosystem service value estimation, determine The weights of each ecosystem service were calculated, and the weighted overlay analysis was carried out to obtain the spatial distribution results of the importance of ecosystem services.
2. Ecological sensitivity
The specific grading standards for ecological sensitivity mainly refer to the "Interim Regulations for Ecological Function Zones", "Technical Guidelines for the Delineation of Ecological Protection Red Lines" issued by the Ministry of Ecology and Environment, the grading standards of the national ecological sensitivity index system for ecological function zoning work, and related research. Sensitivity index system for ecological sensitivity analysis.
3. Spatial analysis to extract ecological sources
Overlay the ecologically sensitive areas and the evaluation results of the importance of ecosystem services, and use the hotspot analysis tool of the ArcGIS Pro spatial analysis module to identify the hot and cold areas of ecosystem importance after the overlay,
2. Construction of resistance surface model
Species will be hindered when migrating between different landscape units, so it is necessary to calculate their dispersal paths under the condition of overcoming resistance by constructing resistance. On the basis of determining the ecological source, according to the minimum resistance accumulation model, the ecosystem service value of each grid unit is regarded as the resistance to service flow, and the higher the value, the smaller the resistance.
1) Analysis of factors affecting spatial resistance (elevation, slope, vegetation coverage factors, roads, etc.)
2) Determination of resistance coefficient and weight
3) Resistance surface extraction
3. Extraction of resistance model ecological corridor
The ecological corridor is the channel with the lowest resistance between two source patches, and the connection between the source patches in the region needs to be established by constructing ecological corridors.
The identification of ecological corridors in the region usually uses the least resistance model to simulate and generate the corridors, and then combines the existing urban ecological corridors, or makes corrections according to the status quo of the ground objects, so as to determine the location and width of the ecological corridors.
4. Extraction of ecological corridors of circuit models
Circuit theory refers to using the characteristics of electrons to walk randomly in the circuit to simulate the migration and diffusion process of individual species or genes in the landscape, and to use the current intensity between sources to reflect the relative importance of ecological patches and corridors, thereby predicting species dispersal This method is more in line with the real species movement situation;
1) Ecological sources: Each ecological source is used as a circuit node, and the cumulative resistance of each link between two nodes is calculated according to the minimum cost path of the resistance surface. The cumulative resistance is specified as the resistance of the link.
2) Ecological pinch: For each pair of circuit nodes, one node is arbitrarily connected to a current of 1 amp, while the other node is connected to ground. The effective resistance is calculated iteratively between all pairs of circuit nodes. For n nodes, there are n ( n − 1)/2 calculations. The cumulative current value reflects the net migration of random walkers to destination nodes and can be used to identify the importance of ecological corridors. The larger the cumulative current value, the more important the area in the landscape. The area with the highest current value is designated as the grip.
3) Ecological barriers: Barriers are identified as key nodes that can greatly enhance ecological source connectivity and ecological restoration. As a certain area is ecologically restored, the area's resistance decreases; therefore, the cumulative resistance of the least-cost paths connecting nodes through the restored area also decreases. Those areas of recovery where the cumulative resistance drops the most are identified as barriers.
Chapter 9 , related SCI paper writing skills
1. Structure of scientific papers
2. Abstract and conclusion
3. Introduction and Discussion
4. Analysis of paper submission skills
5. Case analysis of SCI papers
6. Research direction
