Geographers use socio-economic data to calculate the relative impact of a storm on a country's economy.
Formula:
Example: Typhoon Haiyan's impact on the Philippines
Step 1: Identify the values (Total loss = \13\text{bn}$272\text{bn}$).
Step 2: Substitute into the equation. (\13\text{bn} \div $272\text{bn}) \times 100$
Step 3: Calculate the final percentage.
Analysis: While Hurricane Sandy cost the US \71\text{bn}1%$13\text{bn}5%$ of the Philippines' GDP, causing far greater long-term economic stagnation.
1. Satellite Imagery (Remote Sensing)
2. Social Media and Crowdsourcing
#Sandy hashtag alongside accounts like @FEMA to coordinate shelter locations.Students often confuse primary and secondary impacts. Remember that drowning in the floodwater is a primary impact, but catching cholera from drinking that same floodwater is a secondary impact.
When answering 'Evaluate' questions about cyclone impacts, examiners expect you to contrast Developed (HIC) and Developing (LIC/NEE) countries. Always mention that HICs have higher absolute economic costs but LICs have higher relative costs as a percentage of their GDP.
If an exam question asks you to 'Assess' the use of data sources like satellite imagery or social media, you must explicitly state their limitations (e.g., cloud cover blocking satellites or the digital divide skewing social media data) to access the highest mark bands.
Primary impact
The immediate effects caused directly by the hazard itself, such as buildings collapsing from high winds or drowning in a storm surge.
Secondary impact
The knock-on effects that occur after the initial storm has passed, such as disease outbreaks from contaminated water or economic hardship from job losses.
Storm surge
A temporary and dangerous rise in local sea level caused by low atmospheric pressure and strong winds pushing water onto the coast.
Saltwater intrusion
The movement of saline (salty) water into freshwater aquifers or onto land, which degrades soil and kills salt-sensitive crops.
Poverty trap
A cycle of vulnerability where the financial burden of recovering from a disaster prevents a community or nation from investing in future development and protection.
Multiplier effect
A chain reaction where an initial primary impact (like destroyed boats) leads to further secondary economic and social consequences (like loss of income and reduced access to education).
Quantitative data
Numerical data that can be measured and statistically analysed, such as wind speed, total economic loss, or mortality rates.
Qualitative data
Non-numerical, descriptive information that provides context about human experience and sentiment, such as eyewitness social media reports.
Remote sensing
The process of gathering information about the Earth's surface from a distance, typically using satellite imagery or aircraft.
GIS (Geographic Information System)
A digital framework used to layer data (e.g., satellite imagery over population density maps) to identify high-risk zones and map disaster extents.
Social sensing
The use of real-time social media data and online human interactions to monitor and understand unfolding events during a crisis.
Crowdsourcing
The practice of obtaining information or services by soliciting contributions from a large group of people, often online volunteers mapping disaster zones.
3W mapping
A spatial coordination tool used by aid agencies to visualise 'Who is doing What, Where' to prevent overlaps or gaps in disaster relief.
Digital divide
The gap between demographics and regions that have access to modern information and communications technology, and those that don't.
Put your knowledge into practice — try past paper questions for Geography B
Primary impact
The immediate effects caused directly by the hazard itself, such as buildings collapsing from high winds or drowning in a storm surge.
Secondary impact
The knock-on effects that occur after the initial storm has passed, such as disease outbreaks from contaminated water or economic hardship from job losses.
Storm surge
A temporary and dangerous rise in local sea level caused by low atmospheric pressure and strong winds pushing water onto the coast.
Saltwater intrusion
The movement of saline (salty) water into freshwater aquifers or onto land, which degrades soil and kills salt-sensitive crops.
Poverty trap
A cycle of vulnerability where the financial burden of recovering from a disaster prevents a community or nation from investing in future development and protection.
Multiplier effect
A chain reaction where an initial primary impact (like destroyed boats) leads to further secondary economic and social consequences (like loss of income and reduced access to education).
Quantitative data
Numerical data that can be measured and statistically analysed, such as wind speed, total economic loss, or mortality rates.
Qualitative data
Non-numerical, descriptive information that provides context about human experience and sentiment, such as eyewitness social media reports.
Remote sensing
The process of gathering information about the Earth's surface from a distance, typically using satellite imagery or aircraft.
GIS (Geographic Information System)
A digital framework used to layer data (e.g., satellite imagery over population density maps) to identify high-risk zones and map disaster extents.
Social sensing
The use of real-time social media data and online human interactions to monitor and understand unfolding events during a crisis.
Crowdsourcing
The practice of obtaining information or services by soliciting contributions from a large group of people, often online volunteers mapping disaster zones.
3W mapping
A spatial coordination tool used by aid agencies to visualise 'Who is doing What, Where' to prevent overlaps or gaps in disaster relief.
Digital divide
The gap between demographics and regions that have access to modern information and communications technology, and those that don't.