Practice of GIS in Geological Hazard Risk Assessment and Post-disaster Reconstruction

Chapter 1 Basic Concepts and Platform Introduction

1. Basic concepts

Types of geological hazards

The Developmental Characteristics and Distribution Rules of Geological Hazards

Hazard Characteristics of Geological Hazards

Analysis of Geological Conditions Pregnant in Geological Hazards

Inducing Factors and Forming Mechanism of Geological Disasters

2. GIS principle and ArcGIS platform introduction

Introduction to GIS

ArcGIS Basics

Spatial Data Acquisition and Organization

spatial reference

Transformation and processing of spatial data

Data Editing in ArcGIS

Visual representation of geographic data

Space Analysis:

Digital Terrain Analysis

Overlay Analysis

distance mapping

Density Mapping

Statistical Analysis

rearrange

3D analysis

Chapter II Geological Hazard Risk Assessment Model and Method

1. Evaluation model and method of geological disaster susceptibility

Evaluation unit determined

Susceptibility evaluation index system

Susceptibility Evaluation Model

Determination of weight

2. Evaluation of landslide susceptibility

Evaluation System

Terrain: elevation, slope, gully density, relief, etc.

Landform: landform unit, micro-geomorphology, overall topography, etc.

Stratum lithology: lithological characteristics, rock thickness, rock genetic type, etc.

Geological structure: faults, folds, joint fissures, etc.

Earthquake: Intensity, dynamic peak acceleration, historical seismic activity, etc.

Engineering geology: regional crustal stability, bedrock burial depth, main bearing layer lithology, bearing capacity, rock and soil engineering geological division, etc.

Extraction of common indicators

Factor extraction such as slope, slope type, elevation, terrain relief, fault zone distance, engineering geological rock group, slope structure, vegetation coverage, distance from water system, etc.

Index Factor Correlation Analysis

(1) Calculation and analysis of correlation coefficient

(2) Collinearity diagnosis

The amount of evaluation index information

Evaluation index weight determination

Analysis and drawing of landslide susceptibility assessment results

Landslide Susceptibility Composite Index

Susceptibility Classification

Graphical analysis of susceptibility evaluation results

2. Evaluation of collapse susceptibility

3. Evaluation of debris flow susceptibility

Debris flow evaluation unit extraction

Debris Flow Evaluation Index

Severity of landslides, length ratio of sediment recharge along the course, debris flow accumulation activity at the gully mouth, longitudinal slope of valleys, degree of regional structural influence, vegetation coverage of watersheds, engineering geological rock formations, reserves of loose deposits along the gully, watershed area, watershed Relative height difference, degree of channel blockage, etc.

Selection of Evaluation Indexes for Typical Debris Flows

Evaluation factor weight determination

Analysis and Mapping of Evaluation Results of Debris Flow Susceptibility

Calculation of Debris Flow Susceptibility Composite Index

Determination of Susceptibility Classification of Debris Flows

Evaluation results of debris flow susceptibility

4. Comprehensive evaluation of susceptibility to geological disasters

Comprehensive geological disaster susceptibility value = MAX [debris flow disaster susceptibility value, collapse disaster susceptibility value, landslide disaster susceptibility value]

Chapter 3 Risk Assessment of Geological Hazards

1. Risk assessment of geological disasters

2. Risk assessment of geological disasters

Selection of risk assessment factors

Under the action of certain triggering factors, the possibility of geological disasters of a certain scale and type occurring in a certain period of time in a certain area.

The complexity of regional structures, the development of active faults, and seismic activity may all induce geological disasters; the induction of heavy rainfall, the frequency and scale of disasters will also increase the probability of geological disasters.

Quantification of risk assessment factors

Quantification of risk factors for landslides

Count the number and area of ​​disasters at all levels, and use the information volume calculation method to obtain the information volume values ​​at all levels.

Debris flow risk assessment factor weight

Risk assessment and result analysis

3. Assessment of vulnerability to geological hazards

Vulnerability Factor Analysis of Geological Hazards

population vulnerability

house building vulnerability

agricultural vulnerability

forestry vulnerability

Livestock vulnerability

road traffic vulnerability

water vulnerability

Population Vulnerability Evaluation Factor Extraction

Population Density Data Processing

Use population density data to quantify population vulnerability, based on the population numbers obtained from the statistical yearbooks of each administrative unit, combined with housing construction area data, to quantify the spatial distribution of population, and based on GIS grid analysis, the population per unit area is obtained. density.

vulnerability assignment

Population Vulnerability Factor Extraction

Building Vulnerability Assessment

Data Processing of Building Area Density

Quantifying building vulnerability with building-building area density data, using building-building area data,

Based on the grid analysis of GIS, the area of ​​the building area per unit area is obtained, that is, the density of the building area.

vulnerability assignment

Extraction of Building Vulnerability Factors

Vulnerability Assessment of Transportation Facilities

Acquisition of road data

Use the ArcGIS buffer analysis function to form the surface file of the road

Different types of roads for assignment

Analysis of Road Vulnerability Distribution Results

Comprehensive Vulnerability Assessment

Combined Vulnerability Overlay Weight

Extraction and Analysis of Comprehensive Vulnerability Evaluation Results

4. Extraction and analysis of geological disaster risk assessment results

​Chapter Four: Application of GIS in post-disaster reconstruction

1. Analysis of emergency rescue path planning

Spatial analysis such as surface analysis, cost weighted distance, and raster data distance mapping;

Using the basic method of thematic map drawing, the emergency rescue route map for geological disasters in Maoxian County, Sichuan Province was made,

Extraction and analysis of the best path

2. Site selection analysis for disaster recovery and reconstruction

Determining the influencing factors of site selection

Determine the weight of each impact factor

Collect and process data for each influencer: terrain analysis, distance mapping analysis, reclassification

Restoration and reconstruction site selection analysis

3. Analysis of ecological environment changes after the earthquake

Use the powerful data acquisition, data processing, data storage and management, spatial query and spatial analysis, visualization and other functions of this type of software to evaluate ecological environment changes.

Chapter 5 Advanced: Python machine learning application and paper writing and reproduction

1. Analysis of the main points of thesis writing

2. Analysis of paper submission skills

3. Case analysis of the paper

Case: Research on Disaster Susceptibility Evaluation Using Machine Learning

Some results are reproduced:

Model introduction:

√ Logistic regression model

√ Random Forest Model

√ Support vector machine model

Implementation plan:

1. Operating environment deployment

√Python compilation environment configuration

√ sklearn library

2. Linear Probability Model - Logistic Regression

√ Introduction

√ Selection of connection function: Sigmoid function

√Disaster-causing factor data set: data introduction; correlation analysis; logistic regression model prediction; sample precision analysis; classification confusion matrix

√ Precautions

Three, SVM support vector machine

√ Linear Classifier

√SVM-kernel method: Introduction to kernel method; sklearn's SVM kernel method

√ Parameter optimization and adjustment

√ SVM data set: support vector machine model prediction; sample accuracy analysis; classification confusion matrix

4. Python Implementation of Random Forest

√Dataset

√ Random selection of data

√Random selection of features to be selected

√ Explanation of related concepts

√Parameter optimization and adjustment: random forest decision tree depth tuning; CV cross-validation definition; confusion matrix; sample precision analysis

√ Implementation of Random Forest based on pandas and scikit-learn: data introduction; random forest model prediction; sample accuracy analysis; classification confusion matrix

5. Comparative analysis of methods

√Accuracy analysis

√ Comparative analysis of results

Original reading: Practical technology application of GIS in geological disaster risk assessment and post-disaster reconstruction and python machine learning disaster susceptibility evaluation model

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Origin blog.csdn.net/weixin_56135535/article/details/131003836