its about climate change and water-related disasters.

1. Subject: Climate Change and Water-
related Disasters
Presented to: Prof. Li Yi
Presented By:
Mohsin Ijaz （李浩）
Student ID: 2024072106

2. Title: Understanding Flash Drought Disasters
• Introduction
• Mechanisms of Flash Droughts
• Flash Drought Indices
• Causes of Flash Droughts
• Impacts (Agricultural, Environmental, Social, Economical)
• Mitigation Strategies

3. WHAT IS DROUGHT??
Drought: A drought is a period of unusually persistent dry weather that continues long
enough to cause serious problems such as crop damage and/or water supply shortages.
Droughts are caused by low precipitation over an extended period of time.(NASA)

4. Flash Drought
• Definition: Flash droughts are rapid-onset droughts that develop and intensify over
a few weeks. Unlike traditional droughts, which gradually reduce moisture, flash
droughts strike quickly.
• Characteristics: Develops within a short time frame (weeks instead of months or
years).
•Severity: Often leads to significant agricultural damage and water scarcity.
•Intensity: Results in high evaporation rates and decreased soil moisture.
• Speed of Development: Due to high evaporation rates and significant temperature
anomalies, conditions escalate quickly.
• Comparison to Traditional Droughts: Traditional droughts have a slow onset and
are usually more predictable. Flash droughts, however, are more challenging to
anticipate and respond to due to their rapid development.

6. Mechanisms of Flash Droughts
• Meteorological Conditions: High temperatures, low humidity, and minimal
cloud cover accelerate soil moisture depletion.
• Soil Moisture Dynamics: The moisture in topsoil layers evaporates quickly
under these conditions, while deeper soil moisture reserves are not replenished.
• Role of Evapotranspiration: Increased rates of evapotranspiration due to high
temperatures draw moisture from both plants and soil, rapidly creating drought
conditions.

7. Causes of Flash Droughts
• Atmospheric Patterns: Persistent high-pressure systems lead to clear skies, dry
weather, and intense sunlight.
•
Climate Change Factors: Warmer global temperatures contribute to the intensity
and frequency of flash droughts.
• Human Activities: Land-use changes, deforestation, and excessive water
withdrawal exacerbate drought potential, reducing the natural ability of land to
retain water.

8. Key Triggers for Flash Droughts
• Heat Waves: Prolonged periods of extreme heat trigger rapid drying of soil and
vegetation.
• Lack of Precipitation: Even a brief dry spell can initiate a flash drought if
temperatures are high enough.
• Wind and Low Humidity: These conditions drive high rates of evaporation,
pulling moisture from the ground and vegetation.

9. Climate Change and Flash Drought Frequency
• Global Warming Influence: Rising temperatures lead to an increase in
heatwaves, which are often a precursor to flash droughts.
• Extreme Weather Patterns: Increasing volatility in weather, such as more
frequent and intense heatwaves, makes flash droughts more common.
• Future Projections: Based on climate models, the likelihood of flash droughts
is expected to rise in many regions, posing threats to ecosystems, agriculture,
and water resources.

10. Standardized Precipitation Evapotranspiration Index (SPEI)
•Input Parameters: Precipitation, Potential Evapotranspiration (PET)
•Benefits:
•Accounts for both precipitation deficit and temperature-driven evapotranspiration.
•Flexible timescale options, capturing short-term dryness for flash drought analysis.
•Limitations:
•Requires PET data, which can be complex to compute.
•Sensitive to PET estimation method, affecting accuracy.

11. Evaporative Stress Index (ESI)
• Input Parameters: Evapotranspiration (ET), Reference ET from remote
sensing data
• Benefits:
• Directly monitors vegetation stress, enhancing drought detection.
• High spatial resolution due to remote sensing.
• Limitations:
• Dependent on clear skies for remote sensing data accuracy.
• Limited data availability in regions with cloud cover.

12. Soil Moisture Percentile (SMP)
Input Parameters: Soil moisture data from in-situ sensors or models
•Benefits:
•Direct measure of soil water content, highly relevant for agricultural flash droughts.
•Immediate response to precipitation changes.
•Limitations:
•Limited spatial coverage; may not represent broader regions.
•Model-derived soil moisture can have biases.

13. Standardized Soil Moisture Index (SSI)
•Input Parameters: Soil moisture data standardized over time
•Benefits:
•Standardization allows drought comparison across regions.
•Effective for detecting rapid changes in soil moisture.
•Limitations:
•Requires historical soil moisture records for standardization.
•Not readily available in all locations due to limited soil moisture data.

14. Rapid Change Index (RCI)
• Input Parameters: Any drought indicator (e.g., soil moisture, ET) measured over time
• Benefits:
• Captures rapid changes in drought indicators, making it ideal for flash drought.
• Flexible to use with multiple types of data sources.
• Limitations:
• Requires frequent data updates, which may not be available.
• Sensitivity to baseline data quality affects reliability.

15. Impacts of Flash Drought
• Impacts on Agriculture
• Environmental Impacts
• Economic Impacts
• Social Impacts

16. Impacts on Agriculture
•Crop Losses: Plants experience water stress, leading to reduced yields and in some
cases, complete crop failure, especially for crops with high water demand.
•Soil Health: Loss of soil moisture leads to soil compaction and reduced fertility,
making recovery harder.
• Food Security Concerns: Reduced agricultural productivity can impact global
food supplies, leading to higher prices and scarcity.

17. Environmental Impacts
• Ecosystem Disruptions: Vegetation and wildlife accustomed to stable water
sources may face stress or displacement.
• Water Body Depletion: Lower levels in rivers, lakes, and reservoirs reduce
habitat for aquatic life and limit water availability for nearby communities.
• Increased Wildfire Risks: Dry conditions heighten wildfire susceptibility,
endangering forests and wildlife.

18. Social Impacts
• Health Issues: Intense heat and limited water availability increase the risk of
dehydration and heat-related illnesses.
• Community Displacement: Prolonged water scarcity may force migration, as
agricultural and economic opportunities decrease.
• Mental Health Effects: The stress of dealing with water scarcity, crop losses,
and financial uncertainty can affect individuals’ mental well-being.

19. Economics Impacts
• Financial Losses in Agriculture: Crop failures and reduced yields lead to income
losses for farmers and supply-chain disruptions.
• Infrastructure Stress: Strains on water infrastructure as demand rises, including
costs associated with repairing and upgrading systems.
• Insurance Costs: Increased risks translate to higher premiums, making drought-
prone areas financially vulnerable.

20. Mitigation Strategies
• Monitoring and Early Warning Systems
• Mitigation Strategies in Agriculture
• Policy and Management Solutions
• Future Research and Development

21. Monitoring and Early Warning Systems
• Remote Sensing: Satellite data helps monitor soil moisture and vegetation health,
providing early signs of drought.
• Soil Moisture Monitoring: In-situ and remote sensors offer real-time data on soil
water levels.
• Predictive Models: Climate models and AI-driven analytics enhance prediction
capabilities, improving lead time for flash droughts.

22. Mitigation Strategies in Agriculture
• Efficient Irrigation Systems: Drip irrigation and other systems reduce water
wastage, especially critical during droughts.
• Drought-Resistant Crops: Use of genetically modified or selectively bred crops
that withstand dry conditions.
• Soil Conservation: Techniques like mulching, no-till farming, and cover crops
help retain soil moisture and enhance resilience.

23. Policy and Management Solutions
• Sustainable Water Management: Policies focused on responsible water use,
such as tiered water pricing and water-saving incentives.
• Community Planning: Risk assessments for flash droughts, especially in
vulnerable regions, to enhance community resilience.
• Emergency Funding: Reserve funds and financial support for rapid response to
flash drought impacts on affected communities.

24. Future Research and Development
• Technology Development: Innovation in satellite imagery, sensors, and
predictive models to improve early detection.
• Adaptation to Climate Change: Research on adapting agriculture, ecosystems,
and water infrastructure to withstand flash drought impacts.
• International Collaboration: Shared resources and knowledge between countries
to address flash drought challenges globally.

25. Case Studies: flash drought event (e.g., the 2012 U.S. flash
drought or Australia’s recurring flash drought in 2022).

26. Australia’s recurring flash drought 2022