Tectonic Hazards and Mass Movement: A Comprehensive Analysis

Executive Summary

This document explores the dynamic relationship between tectonic hazards and risk assessment, examining why these natural phenomena present unique challenges for prediction and mitigation. It further investigates mass movement hazards, slope stability mechanics, and the potential for hazard prediction based on scientific understanding.

Part 1: The Dynamic Nature of Tectonic Hazards and Risk

1.1 Understanding Tectonic Hazards as Complex Risk Systems

Tectonic hazards represent one of the most challenging natural phenomena to assess in terms of risk due to their inherent complexity, variable spatial distribution, and unpredictable temporal patterns. These hazards include earthquakes, volcanic eruptions, and tsunamis, all of which emerge from processes occurring deep within Earth’s lithosphere.

1.2 Why Risk Assessment of Tectonic Hazards is Difficult

Temporal Unpredictability

The fundamental challenge in tectonic risk assessment lies in the inability to predict precisely when events will occur. While seismologists can identify high-risk zones based on plate boundary locations and historical data, pinpointing the exact timing of earthquakes remains scientifically elusive. Recurrence intervals for major earthquakes can span centuries or millennia, making probability calculations highly uncertain.

Spatial Variability and Cascade Effects

Tectonic events exhibit extreme spatial variability in their impacts. A magnitude 7.0 earthquake can cause devastating destruction in one location while producing minimal damage in another, depending on factors such as:

Depth of the hypocenter
Local geology and soil composition
Building construction standards
Population density
Time of day when the event occurs

Furthermore, tectonic hazards trigger cascade effects (secondary hazards) including landslides, tsunamis, liquefaction, and fires, creating multi-dimensional risk scenarios that are difficult to model comprehensively.

Exposure and Vulnerability Dynamics

Risk is a function of hazard probability, exposure, and vulnerability (Risk = Hazard × Exposure × Vulnerability). In tectonic contexts:

Exposure constantly changes as populations grow and urban areas expand into hazardous zones
Vulnerability varies dramatically based on socioeconomic factors, building codes, and preparedness levels
Hazard assessment itself contains significant uncertainties due to incomplete historical records and limited understanding of deep Earth processes

Data Limitations

Comprehensive seismic records only exist for the past 100-150 years in most regions, representing an infinitesimally small sample of geological time. This limited dataset makes it challenging to establish accurate recurrence intervals for rare but catastrophic events.

Technological and Scientific Constraints

Despite advances in seismology and volcanic monitoring, our ability to observe processes occurring 10-700 kilometers below the surface remains limited. Earthquake prediction, in particular, has proven remarkably resistant to scientific advances, with no reliable short-term prediction method yet developed.

Part 2: The Concept of Resilience

2.1 Defining Resilience in Tectonic Hazard Contexts

Resilience refers to the capacity of individuals, communities, institutions, and systems to survive, adapt, and recover from tectonic hazards while maintaining essential functions and structures. Unlike simple resistance (which implies withstanding without change), resilience acknowledges that change is inevitable and focuses on the ability to bounce back or even transform positively after disruption.

2.2 Components of Resilience

Technical Resilience

Earthquake-resistant building design and construction
Redundant infrastructure systems
Early warning systems for tsunamis and volcanic eruptions
Seismic retrofitting of existing structures

Organizational Resilience

Emergency response protocols and disaster management agencies
Communication systems that function during and after disasters
Coordination between government agencies, NGOs, and community organizations
Medical and rescue service capacity

Social Resilience

Community cohesion and social networks
Public education and hazard awareness
Cultural practices that incorporate disaster preparedness
Equitable distribution of resources and support systems

Economic Resilience

Diversified economic base that can withstand disruption
Insurance mechanisms and financial safety nets
Rapid economic recovery capabilities
Investment in preventive measures rather than only reactive responses

2.3 Building Resilience

Resilience is enhanced through:

Preparedness: Drills, education, and planning before events occur
Adaptation: Learning from past events and incorporating lessons into future planning
Redundancy: Multiple systems to perform critical functions
Flexibility: Ability to modify responses based on evolving circumstances
Equity: Ensuring all community members have access to protective resources

Part 3: Social and Economic Impacts of Tectonic Hazards

3.1 Social Impacts

Immediate Human Casualties

The most direct and tragic impact involves loss of life and injuries. The 2010 Haiti earthquake killed an estimated 220,000-300,000 people, while the 2011 Tōhoku earthquake and tsunami in Japan resulted in approximately 18,500 deaths.

Displacement and Migration

Tectonic disasters create both temporary and permanent displacement. The 2015 Nepal earthquakes displaced over 2.8 million people, with many unable to return to their homes for extended periods. Some communities are permanently relocated when areas become uninhabitable.

Psychological Trauma

Survivors experience profound psychological impacts including:

Post-traumatic stress disorder (PTSD)
Anxiety and depression
Loss of sense of security
Grief from loss of loved ones and community
Intergenerational trauma effects

Social Structure Disruption

Tectonic events disrupt:

Family units and social networks
Educational systems (destroyed schools, displaced students)
Healthcare access
Community cohesion
Cultural heritage sites and practices

Inequality Amplification

Tectonic hazards disproportionately affect vulnerable populations:

Poor communities often live in more hazardous locations with substandard construction
Marginalized groups have less access to early warning systems and evacuation resources
Recovery resources may not reach all affected populations equally
Disasters can widen existing social and economic inequalities

3.2 Economic Impacts

Direct Economic Losses

Infrastructure destruction: Roads, bridges, ports, airports, utilities
Building damage and collapse: Residential, commercial, and industrial structures
Agricultural losses: Damaged farmland, livestock deaths, disrupted food supply
Industrial disruption: Factory damage, supply chain interruptions

The 2011 Japan earthquake generated economic losses estimated at $235 billion, making it the costliest natural disaster in recorded history.

Indirect Economic Losses

Business interruption: Lost productivity, closed businesses, unemployment
Tourism decline: Reduced visitor numbers affecting hospitality sectors
Investment flight: Reduced investor confidence in affected regions
Trade disruption: Damaged ports and transportation networks affecting international commerce
Insurance costs: Increased premiums for affected and even unaffected regions

Long-term Economic Consequences

Reconstruction costs: Often exceed initial damage costs
Debt burden: Governments may need to borrow extensively for recovery
Economic development setbacks: Years or decades of development progress can be erased
Poverty increases: Families lose assets, employment, and economic security
Migration of skilled workers: Brain drain as professionals leave affected areas

Positive Economic Paradoxes

Interestingly, some economic research suggests that reconstruction can stimulate economic activity through:

Infrastructure modernization
Employment in construction and rebuilding sectors
Investment in more resilient systems
Innovation in disaster-resistant technologies

However, these potential benefits rarely compensate for the massive destruction and human suffering.

Part 4: Mass Movement Hazards and Slope Stability

4.1 Understanding Slope Stability

Slope stability refers to the resistance of an inclined surface to failure by sliding or collapsing. The fundamental principle governing slope stability is the balance between driving forces (which promote movement) and resisting forces (which prevent movement).

The Stability Equation

Slope stability is often expressed as a Factor of Safety (FoS):

FoS = Resisting Forces / Driving Forces

When FoS > 1.0: Slope is stable
When FoS = 1.0: Slope is at the threshold of failure
When FoS < 1.0: Slope failure is imminent or occurring

Factors Affecting Slope Stability

Geological Factors:

Rock or soil type and strength
Layering and discontinuities (bedding planes, joints, faults)
Weathering degree
Slope angle and height

Environmental Factors:

Vegetation cover (roots provide cohesion)
Climate and precipitation patterns
Groundwater conditions
Seismic activity

Human Factors:

Excavation and construction activities
Deforestation
Irrigation and water management
Loading of slopes with structures or materials

Part 5: Gravity and Water in Mass Movement Events

5.1 The Role of Gravity

Gravity as the Primary Driver

Gravity is the fundamental driving force in all mass movement events. It acts continuously on all slope materials, creating a downslope component of force. The gravitational force component parallel to the slope (shear stress) increases with:

Steeper slope angles
Greater mass of material
Height of the slope

Gravitational Stress Distribution

The normal stress (perpendicular to the slope) and shear stress (parallel to the slope) can be calculated as:

Normal stress = mg cos θ (where θ is slope angle)
Shear stress = mg sin θ

As slope angle increases, shear stress increases while normal stress decreases, making failure more likely.

Types of Mass Movements Dominated by Gravity

Rockfalls: Free-falling rock from steep cliffs
Topples: Forward rotation of rock masses
Avalanches: Rapid downslope movement of snow, ice, rock, or soil

5.2 The Role of Water

Water acts as a critical modifier of slope stability through multiple mechanisms:

Increased Weight

Water adds mass to slope materials, increasing the gravitational driving force. Saturated soil can weigh nearly twice as much as dry soil, significantly increasing downslope stress.

Pore Water Pressure

This is perhaps water’s most significant effect. Water filling spaces between soil particles generates pore pressure that:

Reduces effective normal stress between particles
Decreases frictional resistance
Reduces cohesion in certain materials
Can create a “hydroplaning” effect where materials slide on a water layer

The effective stress principle states: Effective Stress = Total Stress – Pore Water Pressure

As pore water pressure increases, effective stress decreases, reducing the frictional resistance that keeps slopes stable.

Erosion and Weathering

Water causes:

Physical erosion of toe slopes (removing support)
Chemical weathering (weakening rock and soil)
Freeze-thaw cycles (expanding and fracturing materials)
Piping (internal erosion creating subsurface voids)

Loss of Cohesion

In clay-rich soils, water can reduce cohesive bonds between particles, dramatically reducing shear strength. However, in some materials, small amounts of water can actually increase cohesion (capillary action).

Types of Mass Movements Dominated by Water

Debris flows: Rapidly moving mixtures of water, rock, and soil
Mudflows: Water-saturated fine-grained materials
Slumps and earthflows: Slower movements in saturated conditions
Liquefaction: Soil behaving as a liquid due to water saturation and vibration

Part 6: Can Gravity or Water Mitigate Each Other’s Effects?

6.1 Can Water Mitigate Gravity’s Effects?

Generally, No – Water Cannot Mitigate Gravity

Water cannot counteract gravity’s fundamental downslope pull. Instead, water typically amplifies gravity’s destabilizing effects through the mechanisms described above. However, there are very limited circumstances where water might provide temporary stability:

Capillary tension: In unsaturated fine-grained soils, small amounts of water can create apparent cohesion through surface tension between particles. This is why damp sand can stand vertically while dry sand cannot.
Frozen water (ice): Ice can cement particles together, increasing slope stability. Permafrost regions maintain steep slopes that would fail if thawed.

These are not true mitigations of gravity but rather special cases where water’s presence temporarily increases resisting forces.

6.2 Can Gravity Mitigate Water’s Effects?

No – Gravity Cannot Mitigate Water’s Destabilizing Effects

Gravity cannot counteract water’s destabilizing mechanisms. In fact, gravity and water work synergistically to promote slope failure:

Gravity pulls water downward through soil, increasing saturation
Gravity enhances the effectiveness of erosional processes driven by water
The combination of gravitational stress and water-induced pore pressure creates conditions more unstable than either force alone

6.3 Management and Engineering Mitigation

While neither natural force can mitigate the other, human interventions can address both:

Drainage Management (Controlling Water)

Subsurface drainage systems to reduce pore water pressure
Surface water diversion channels
Horizontal drains installed into slopes
Vegetation to increase evapotranspiration

Structural Solutions (Addressing Gravity)

Retaining walls to support slopes
Rock bolts and soil nails to increase resistance
Reducing slope angles through regrading
Buttressing toe slopes to increase resisting force
Removing unstable material to reduce driving mass

Combined Approaches

The most effective slope stabilization programs address both factors simultaneously, recognizing that the interaction between gravitational stress and water infiltration creates the critical failure conditions.

Part 7: Triggering Events for Mass Movements

7.1 Seismic Triggering

Earthquake-Induced Failures

Earthquakes are among the most significant triggers for mass movements:

Ground shaking temporarily increases stress beyond slope materials’ resistance
Cyclic loading causes progressive strength loss in saturated materials
Liquefaction occurs when saturated loose sands lose strength during shaking
Ground rupture can directly destabilize slopes along fault lines

Notable examples:

The 2008 Wenchuan earthquake in China triggered over 200,000 landslides
The 1964 Alaska earthquake caused massive submarine slides and generated tsunamis
The 2015 Nepal earthquakes produced thousands of landslides in the Himalayas

Volcanic Activity

Volcanic eruptions trigger mass movements through:

Ground deformation and seismic activity
Rapid snow and ice melting creating lahars (volcanic mudflows)
Lateral blast effects destabilizing slopes
Accumulation of unstable volcanic deposits

7.2 Hydrological Triggering

Intense Rainfall

Short-duration, high-intensity rainfall events or prolonged precipitation can trigger failures by:

Rapidly increasing pore water pressure
Saturating previously unsaturated materials
Increasing weight of slope materials
Reducing effective stress and shear strength

Rainfall thresholds for landslide initiation vary by region but are typically expressed as intensity-duration relationships.

Rapid Snowmelt

Spring snowmelt or rain-on-snow events can rapidly saturate slopes, particularly problematic when:

Frozen ground prevents infiltration
Water accumulates at the soil-bedrock interface
Rapid temperature changes cause sudden water release

Groundwater Changes

Rising groundwater tables from seasonal changes
Reservoir filling behind dams
Irrigation practices
Artificial pond or lake creation

7.3 Anthropogenic Triggering

Excavation and Construction

Road cuts creating oversteepened slopes
Removal of toe support
Overloading slope crests with fill material
Vibrations from construction equipment or blasting

Deforestation

Removal of vegetation triggers failures by:

Eliminating root reinforcement
Increasing soil moisture (reduced transpiration)
Exposing soil to erosion
Removing weight that provided stabilizing normal stress

Mining Activities

Creation of unstable waste rock piles
Slope oversteepening in open pits
Groundwater changes from dewatering
Vibrations from blasting operations

7.4 Progressive Failure and Creep

Not all mass movements require discrete triggering events:

Soil creep: Slow, continuous downslope movement under gravitational stress
Progressive failure: Gradual strength loss over time leading to eventual collapse
Weathering processes: Slow weakening of rock masses
Differential settlement: Gradual deformation creating failure conditions

Part 8: Predicting Mass Movement Hazards

8.1 Can Predictions Be Made?

Yes, but with significant limitations. Mass movement hazard prediction is considerably more advanced than earthquake prediction, though perfect prediction remains impossible. Predictions can be categorized into three types:

1. Spatial Prediction (Susceptibility Mapping)

This answers “WHERE might mass movements occur?” and is the most successful type of prediction.

Methods:

Geological and geomorphological mapping
Identification of previous landslide scarps and deposits
Slope angle analysis using Digital Elevation Models (DEMs)
Rock and soil strength testing
Groundwater condition assessment
Historical landslide inventories

Outputs:

Landslide susceptibility maps showing relative hazard levels
Identification of high-risk zones for land-use planning
Building code recommendations for different hazard zones

Success Rate: High – We can reliably identify areas prone to mass movements based on geological conditions, slope geometry, and historical evidence.

2. Temporal Prediction (When Events Might Occur)

This addresses “WHEN might mass movements occur?” and is more challenging.

Methods:

Rainfall threshold monitoring
Real-time groundwater level measurement
Slope movement monitoring (inclinometers, GPS, InSAR)
Seismic monitoring in earthquake-prone areas
Weather forecasting integration
Snowpack monitoring

Outputs:

Early warning systems for rainfall-triggered landslides
Evacuation orders based on monitoring data
Closure of roads or facilities in high-risk periods

Success Rate: Moderate to High – Short-term predictions (hours to days) for rainfall-triggered events can be quite successful. Longer-term predictions remain uncertain.

3. Magnitude Prediction (How Large/Destructive)

This predicts “HOW LARGE might the mass movement be?” and is the most difficult.

Methods:

Volume estimation of potentially unstable material
Runout modeling based on slope geometry and material properties
Historical analogue analysis
Physical and numerical modeling

Success Rate: Low to Moderate – Estimating exact volumes and runout distances is highly uncertain, though general magnitude classes can sometimes be predicted.

8.2 The Role of Slope Stability Analysis in Prediction

Quantitative Slope Stability Assessment

Slope stability analysis provides the foundation for mass movement prediction:

Limit Equilibrium Methods: These calculate the Factor of Safety for potential failure surfaces:

Bishop’s method
Janbu’s method
Spencer’s method
Morgenstern-Price method

These analyses can be run with different groundwater conditions, seismic loadings, and material properties to assess how changes affect stability.

Numerical Modeling: Advanced approaches include:

Finite element analysis (FEM)
Finite difference methods (FDM)
Discrete element modeling (DEM)

These can simulate complex failure mechanisms and progressive failure.

Probabilistic Approaches: Recognizing uncertainty in input parameters, probabilistic methods:

Monte Carlo simulation
First-order second-moment (FOSM) analysis
Point estimate methods

These provide probability distributions for Factor of Safety rather than single values.

Limitations of Stability Analysis

Parameter Uncertainty: Soil and rock properties vary spatially; sampling provides incomplete characterization
Failure Surface Assumption: Models typically assume a failure surface shape, but actual failures may be more complex
Three-Dimensional Effects: Most analysis is 2D, but real slopes are 3D with variable conditions
Dynamic Loading: Earthquake effects are difficult to model accurately
Unknown Initial Conditions: Existing stress states and fractures may not be apparent

8.3 Integration of Triggering Event Understanding

Understanding triggering mechanisms significantly enhances prediction capabilities:

Rainfall-Based Prediction Systems

Many regions have established empirical rainfall thresholds:

Example Threshold Equations:

I = α D^(-β) (where I = rainfall intensity, D = duration, α and β are regional constants)
Antecedent rainfall indices that account for prior wetness

When rainfall meets or exceeds thresholds, warnings are issued. Success examples include:

Hong Kong’s landslide warning system
Norway’s regional warning system
Puerto Rico’s rainfall threshold monitoring

Challenges:

Thresholds vary significantly by region and even within regions
Local variations in geology and soil conditions
Previous slope condition affects threshold values
False alarms can lead to warning fatigue

Seismic Triggering Assessment

For earthquake-induced landslides:

Newmark Displacement Analysis: This method estimates cumulative slope displacement during earthquakes based on:

Critical acceleration (acceleration needed to overcome slope resistance)
Expected ground motion characteristics
Earthquake magnitude and distance

Regional Hazard Models: These combine:

Slope characteristics
Seismic hazard maps
Historical earthquake-landslide relationships
Ground motion prediction equations

Limitations:

Earthquake location and magnitude uncertainty
Local site effects on ground motion
Soil liquefaction potential
Unknown pre-existing slope conditions

Monitoring and Early Warning

Real-time monitoring provides the most reliable short-term predictions:

Instrumentation:

Extensometers measuring crack widening
Inclinometers detecting subsurface deformation
Piezometers measuring pore water pressure
GPS monitoring surface displacement
Ground-based and satellite radar (InSAR) detecting movement
Acoustic emission sensors detecting rock fracturing
Seismic monitoring for precursory micro-earthquakes

Warning Systems: When monitoring detects acceleration in slope movement or critical threshold exceedance:

Automatic alarms can be triggered
Evacuation protocols initiated
Transportation corridors closed
Mitigation measures activated

Success Stories:

Italy’s monitoring system at Vajont (too late) taught lessons applied successfully elsewhere
Switzerland’s monitoring of the Randa rockslide enabled evacuations
Japanese real-time monitoring systems for volcanic slopes

8.4 Current State of Mass Movement Prediction

What We Can Predict Well:

Locations at high risk (susceptibility mapping)
Short-term hazards when rainfall thresholds are exceeded (hours to days)
Imminent failures with appropriate monitoring (minutes to hours)
Reactivation of known landslides under certain conditions
General increased hazard following major earthquakes

What Remains Challenging:

First-time failures with no monitoring or prior activity
Exact timing more than a few days in advance
Precise magnitude and runout distance
Multiple interacting triggers (e.g., rainfall + earthquake)
Long-term evolution of slopes over decades
Rare, high-magnitude events with limited historical analogues

8.5 Future Directions in Prediction

Technological Advances:

Machine learning and AI analyzing complex datasets
Improved satellite monitoring (higher resolution, more frequent)
Dense sensor networks with real-time data transmission
Integration of multiple data sources
Improved weather forecasting, especially for extreme rainfall

Scientific Advances:

Better understanding of material behavior under complex loading
Improved modeling of water flow and pore pressure evolution
Understanding of progressive failure mechanisms
Integration of climate change effects into hazard assessments

Practical Implementation:

Community-based monitoring programs
Mobile phone-based early warning dissemination
Integration with disaster management systems
Land-use planning incorporating probabilistic hazard assessments

Conclusion

Key Findings

Tectonic Hazard Risk Assessment remains fundamentally challenging due to temporal unpredictability, spatial variability, data limitations, and the complex interaction between hazard, exposure, and vulnerability. Unlike many other natural hazards, short-term earthquake prediction remains scientifically impossible with current knowledge.
Resilience represents a paradigm shift from simply resisting hazards to accepting that disasters will occur and focusing on recovery capacity. Building resilience requires integrated approaches addressing technical, organizational, social, and economic dimensions.
Social and Economic Impacts of tectonic hazards extend far beyond immediate casualties and physical destruction, creating long-lasting effects on mental health, social structure, economic development, and inequality. The most vulnerable populations typically suffer disproportionately.
Mass Movement Hazards follow more predictable physical principles than tectonic events. Slope stability depends on the balance between driving forces (primarily gravity) and resisting forces, with water playing a critical but complex role in modifying this balance.
Gravity and Water work synergistically rather than in opposition. Neither force can mitigate the effects of the other; instead, their interaction creates the most critical failure conditions. Human engineering interventions can address both factors through drainage control and structural stabilization.
Triggering Events including earthquakes, rainfall, snowmelt, and human activities can push marginally stable slopes into failure. Understanding these triggers is essential for temporal prediction of mass movements.
Mass Movement Prediction is significantly more successful than earthquake prediction, particularly for spatial hazard assessment (susceptibility mapping) and short-term temporal prediction when combined with monitoring. However, perfect prediction remains impossible, and significant uncertainties persist, especially for magnitude and precise timing.

Practical Implications

For hazard management professionals and communities in tectonic hazard zones:

Invest in resilience rather than relying solely on prediction or structural protection
Implement comprehensive monitoring in high-risk areas for mass movements
Develop and maintain early warning systems for rainfall-triggered landslides
Integrate hazard assessments into land-use planning and building codes
Recognize limitations of prediction and maintain appropriate preparedness
Address social vulnerability to reduce disproportionate impacts on marginalized communities
Foster international cooperation in research, monitoring, and disaster response

Research Needs

Future advances require:

Long-term monitoring networks generating datasets for model validation
Interdisciplinary approaches integrating geosciences, engineering, social sciences, and economics
Climate change impact assessments on slope stability and triggering event frequency
Improved understanding of coupled processes (hydrology-mechanics-seismicity)
Development of effective risk communication strategies
Investigation of nature-based solutions for slope stabilization

References and Further Reading

Foundational Texts

Keller, E.A. & DeVecchio, D.E. (2019). Natural Hazards: Earth’s Processes as Hazards, Disasters, and Catastrophes
Highland, L.M. & Bobrowsky, P. (2008). The Landslide Handbook—A Guide to Understanding Landslides. USGS Circular 1325
Cruden, D.M. & Varnes, D.J. (1996). “Landslide Types and Processes.” Transportation Research Board Special Report 247

Slope Stability and Mass Movements

Duncan, J.M., Wright, S.G. & Brandon, T.L. (2014). Soil Strength and Slope Stability
Turner, A.K. & Schuster, R.L. (Eds.) (1996). Landslides: Investigation and Mitigation. Transportation Research Board Special Report 247
Sidle, R.C. & Ochiai, H. (2006). Landslides: Processes, Prediction, and Land Use

Tectonic Hazards and Risk

Alexander, D. (2000). Confronting Catastrophe: New Perspectives on Natural Disasters
Wisner, B., Blaikie, P., Cannon, T. & Davis, I. (2004). At Risk: Natural Hazards, People’s Vulnerability and Disasters
Stein, S. & Wysession, M. (2009). An Introduction to Seismology, Earthquakes, and Earth Structure

Resilience

Manyena, S.B. (2006). “The Concept of Resilience Revisited.” Disasters 30(4): 434-450
Cutter, S.L., et al. (2008). “A Place-Based Model for Understanding Community Resilience to Natural Disasters.” Global Environmental Change 18(4): 598-606

Monitoring and Prediction

Guzzetti, F., et al. (2020). “Geographical Landslide Early Warning Systems.” Earth-Science Reviews 200: 102973
Intrieri, E., et al. (2013). “Design and Implementation of a Landslide Early Warning System.” Engineering Geology 147-148: 124-136

Online Resources

USGS Landslide Hazards Program: https://www.usgs.gov/programs/landslide-hazards
Global Facility for Disaster Reduction and Recovery (GFDRR): https://www.gfdrr.org
United Nations Office for Disaster Risk Reduction (UNDRR): https://www.undrr.org