Condensed Notes on Natural Hazards PDF

AVOID TERM NATRUAL HAZARD According to UNDRR- Terminology aims to promote common understanding of disaster risk reduction and assist efforts of authorities, practitioners and public. HAZARD: process, phenomenon or human activity that causes social, economic or environmental degradation or disrupti...

AVOID TERM NATRUAL HAZARD According to UNDRR- Terminology aims to promote common understanding of disaster risk reduction and assist efforts of authorities, practitioners and public. HAZARD: process, phenomenon or human activity that causes social, economic or environmental degradation or disruption. Categorized by: location, intensity and frequency and probability Types: - **Biological**- epidemic diseases - **Geological**- earthquake; volcano - **Meteorological**- storm and cyclone - **Climatological**- drought; wildfire hydrometeorological - **Hydrological**- flood Quasi-natural hazards: The interaction of humans with the natural environments exacerbates some natural processes: e.g. increased flood magnitude due to coastal settlements Technological hazards: disaster threats from the built environment e.g. major accidents (outside the scope of this course). Na-tech hazards: Some hazards are hybrids of natural and technological. **Example:** Fukushima - Tsunami triggered by the earthquake (magnitude 9.0) caused the Fukushima nuclear accident in March 2011. - Flooding of nuclear power plant caused cooling systems to fail and heating of reactors leading to partial meltdown of fuel rods - Release of radioactive material occurred via gas explosions and deliberate releases by discharge of coolant water into the sea and gas venting into the atmosphere [Hazards across the years:] 2015- 1060 registered events 2017- decrease in registered events but increase in severity 2018- decrease in severity but increase in events 2023- \$250 billion loss worldwide Development of infrastructure alongside economic and social developments = increase in events severity especially for floods **(Yang et al., 2021)** DISASTER: disruption in societal functioning from events interaction with vulnerability. Can be immediate or localized. **VULNERABILITY** - Reflects the level of physical exposure (range of potentially damaging events in particular location) of people and assets to damaging natural events. - Human vulnerability determines the extent to which a natural hazard results in a disaster. - vulnerability can be used to determine the degree of risK **Smith K, (2013)** Improvements in environmental security can reduce vulnerability (e.g. protective structures, planning regulations) 𝑹𝒊𝒔𝒌 = 𝒑 𝐱 𝑳 \(p) negative consequences \(L) probability of losses Social vulnerability (timeline of definitions) Wisner (2004) defines vulnerability as the characteristics of a person or group and their situation that influence their capacity to cope with, resist and recover from the impact of a natural hazard. 'Vulnerable populations are those at risk, not simply because they are exposed to hazard, but as a result of a marginality that makes their life a 'permanent emergency' (Bankoff, 2007, pp29-30). 'In assessing societal impacts, the vulnerability of individuals and communities is as important as the relative magnitude of the hazard' (McEwen and Werritty, 2007, p78). '...the concept of vulnerability still encourages a sense of societies and peoples as weak, passive and pathetic' (Bankoff, 2007, pp34). '...people who live with the daily threat of disaster have frequently evolved certain strategies or coping practices for dealing with effects that are quite successful.' (Bankoff, 2007, pp35. Tsunami Volcano Drought Earthquake Wildfire **FLOOD** (White, 1942) From minutes to months (scale) Spatially variable -- may flood without rainfall (arid environments) From localised street/valley -- region/country People and societies have located near to water courses throughout history Inevitably this has impacted upon these settlements, design, structure and purpose Bridging points, water availability, security, economy, transport... Flood risk can be built into the urban fabric In 2004 there were an estimated 1.74m properties at risk from fluvial and coastal inundation, with approximately 80,000 homes at risk from intraurban flooding (Evans et al., 2004). Urban flooding -- localised precipitation driven flooding. Urban short series missing long-term variability, potentially exacerbating short term trends. [Epigraphic records] Examples: - Benito et al. (2003) - Roggenkamp & Herget, (2014) **RESILLIANCE** Resilience means to **\'jump back\' or \'bounce back\'** and refers to people\'s ability to recover in the shortest possible time with minimal or no assistance. Recent discussion in the literature that vulnerability has to be balanced by \'resilience'. (Gaillard, 2007) **Gaillard, 2007** - resilient societies are those able to overcome the damage caused by the occurrence of natural hazards. Looking at traditional societies Gaillard argues that resilience depends on four factors: a.The nature of the hazard\ b. Pre-disaster social condition\ c. The geographical setting\ d. The rehabilitation policy set up by the authorities **Manyena SB, et al. (2011)** - Concept of \'bounce-forward\' to a better less vulnerable state is essential within the overall notion of resilience. - In certain situations \'bounce back\' may not mean progress, but rather increased vulnerability if the correct post- disaster decisions are not made. **Societal responses (Macdonald et al., 2012)** **'Act of God':** - punishment for moral failings; encouraged view that disasters were inevitable. Parallel practice (cognitive dissonance )- Believing at the same time in two mutually incompatible worldviews, or holding one opinion and acting contrary to it **(Sangster *et al.,* 2012)** **Engineering paradigm:** - 'Hardening' built environments to withstand hazard impacts, - based on increased scientific knowledge. - First emerged during the 18^th^ -early 20^th^ Centuries. roots in geography and human ecology. **(Barrows, 1923)** **Dominant (behavioural) paradigm:** - developed from the work of Gilbert F White - Link between human societies and hazards; chose to settle on hazard land - blended approach combining, forecasting and social science based responses such as improvements in land planning and insurance. \*PHYSICAL PROCESS ARE THE FIRST ORDER DETERMINANTS OF DISASTERS\* **Radical (structuralist) paradigm:** - from the 1970s; - a greater focus on human vulnerability to natural hazards, particularly in less developed countries. Critics: social scientists, suggested that disasters had their root causes in societies and not the hazard**.** **(Hewitt, 1983)- \'Interpretations of Calamity.\'** a. Disasters are considered accidents and unplanned within a society. b. Disasters contrast with normal conditions. c. Hazard reduction = application of science, technology and institutional initiatives. Complexity paradigm: from the 1990s: - Shift towards a greater focus on mitigation and long term recovery - societal vulnerability and resilience **(Sangster H, et al. 2018).** - Also links to global issues of climate change and sustainability. Radical Focus - Long-onset, long-term disasters (e.g. droughts in poor countries) Dominant Focus - Short-onset, short-term disasters (e.g. earthquakes in California) **Current research Agendas** **Disaster Risk reduction (DRR)** [(1990-2000)] - Aimed at preventing new and reducing existing disaster risk and managing residual risk - Contribute to strengthening resilience and achievement of sustainable development. - DRR strategies and policies define goals and objectives across different timescales and with concrete targets, indicators and time frames.\" (UNDRR) [Yokohama Strategy and Plan of Action for a Safer World: 1994] - recognised the existing gaps between the IDNDR's goal, as formulated at the beginning of the Decade, and reality. **Conclusion:** - Intended impact of the technical solutions could only achieve the given goals if they were integrated in an appropriate socioeconomic and political framework. [ISDR (International Decade for Natural Disaster Reduction) (2000-)] - Increase public awareness - Obtain commitment from public authorities to implement disaster reduction policies and actions. - Stimulate interdisciplinary and intersectoral partnerships [Hyogo Framework for Action 2005-2015:] Building the *resilience* of nations and communities to disasters - To substantially reduce disaster losses by 2015 -- in lives, and in the social, economic, and environmental assets of communities and countries. - Integrate disaster risk reduction into sustainable development - strengthen institutions, mechanisms and capacities [ISDR to UNDRR 2]019 - Coordinate the UN disaster reduction programs - Bring governments, partners and communities together to reduce disaster risk and losses to ensure a safer, sustainable future. [Sendai Framework for Disaster Risk Reduction: 2015-2030] **FLOODS** [Social impacts and memory] Extreme floods became part of local folklore -- with the extent and impact recorded in popular songs and stories. - Informal/alternative sources offer opportunities to access information from those who's voices may not be recorded elsewhere - Markings in some cases became powerful tools in the memories of the local populace, with families recounting the loss of lives based a single, or multiple floods. **Music - Jazz -- Mississippi floods 1927 (McEwan, 2013)** **ADJUSTMENT, MITIGATION AND MANAGEMENT** (Burton *et al.,* 1978) Responses to natural hazards in societies. (Chester *et al.,* 2012)  The range of theoretical adjustments to hazards include: 1\. Affecting the cause:\ Modify the hazard (hazard specific)\ Modify the loss potential (e.g. alert systems, planning and civil defence) 2.Adjusting to losses:\ Spread the losses (e.g. public insurance)\ Plan for losses (e.g. insurance)\ Bear the losses Bear the loss\ Plan for losses\ Spread the losses\ Modify the loss potential\ Modify the hazard\ Affect the cause **FLOODS** Theoretical range of adjustments to [floods]: Bear the loss (involuntary adjustment for most of human history and still the case in \'poor\' countries).\ Plan for losses (e.g. insurance and reserve fund).\ Spread the losses (e.g. public relief and subsided insurance).\ Modify the loss potential (e.g. warning systems; emergency evacuation and preparation; building design; land-use change and, permanent evacuation).\ Modify the hazard (e.g. control flood flows by: reservoir storage; levees; channel improvement; flood fighting).\ Affect the cause (e.g. reduce flood flows by: land-use treatment; cloud seeding). **Different strategies to coastal defence** Hard Engineered- withstand heavy events but doesn't adapt with changing conditions Natural Management Approaches- cheaper, large space requied Hybrid Approaches- ecosystem based coastal defence - Natural ecosystem solutions may offer low cost benefits, but over-exploitation must be avoided. e.g. mangroves [Hydrological risk assessment] Management and communication key 1\. Pre- flood warnings 2\. Imminent/during a flood 3\. Post flood event Prepare beforehand - awareness Imminent - communication crucial -- Cost effective, if properties flood -- remove materials where possible up stairs The clean up -- what it looks like. Insurance Natural Flood Management - Investment in flood alleviation schemes in 2021 with further action to improve flood insurance. - More than 1,000 flood schemes to benefit from record investment of over £860 million Defences Hard or soft -- Hard e.g. concrete -- Soft e.g. SuDS Permanent or removable **SuDS** Important development Tool for retaining water in localised areas, significant tool in water management in urban areas Incorporated into local flood management plans - Required for almost all new developments at planning stage - Expensive -- social value **Flood defences** - Flood defences are crucial in some cities - The design specifications for flood defences are carefully considered - To produce reliable designs two factors are required: a\) Design requirement, x-year flood level b\) Knowledge of previous flood levels Flood frequency is reassessed and should be recalculated frequently Flood frequency is not stable - it is the product of events and flood events are stochastic in nature Current practice is to include all available data, this includes historical information - this has been an area of considerable development in flood estimation over the last 10 years Flood defences only protect to the level they are constructed, once exceeded they are of little value Example: Two Lads NFM, Bolton Early quantification of NFM effectiveness. Av. Reduction of 27% during flood events Clear storage during storms Ciara & Denis Working site (Norbury et al., 2021) **Tsunami** **Volcanic hazards** Reliable hazard assessment requires volcano-by- volcano investigation (no 'one size fits all'\ approach). **(Chester *et al.,* 2001)** **Theoretical range of adjustments to [lava flow]**: Bear the loss (involuntary adjustment for most of human history and still the case in \'poor\' countries).\ Plan for losses (e.g. insurance and reserve fund).\ Spread the losses (e.g. public relief and subsided insurance).\ Modify the loss potential (e.g. warning systems; emergency evacuation and preparation; land-use change and, permanent evacuation).\ Modify the hazard (e.g. protect high value installations, alter flow direction and arrest forward movement).\ Affect the cause (e.g. no known method for doing this for lava flows) **Management:** - Lava bomb shelters - Gas alert levels - Lava barriers - Lahar diversion structure [Low-cost equipment] **McGonigle, A.J.S., (2007)** - USB2000- GAS SPECTROMETER **Drought** [Standardised Drought Indicator Family] SPI-like methods have been applied to hydrological variables before -- Standardised Runoff Index- Shukla and Wood (2008) -- Standardised Streamflow Index- Vincente-Serrano et al. (2010) -- Standardised Precipitation-Evapotranspiration Index- Vincente-Serrano et al. (2012) -- Standardised Groundwater Index- Bloomfield & Marchant (2013) Inverse Normal Scores Transformation Rankit scores 𝒓 − 𝟏/𝟐 /𝒏 Improved understanding of drought characteristics, spatial coherence, causes and impacts at both intra and inter-regional spatial scales no significant relationship between the NAO & UK droughts, reflecting the complexity of drought and climate processes. - Recent drought events (2004-2006 & 2010-2012) in the UK highlighted continued vulnerability **Drought Management Plans**- Severn Trent **(Lennard et al., 2014)** - [Produced a temporally extended set of robust rainfall records for use in reconstructing drought histories from around Britain] - [The Elan Aqueduct] **(Harvey-Fishenden et al., 2019) and (Harvey-Fishenden and Macdonald, 2021)** - Politically -- can be difficult to justify to a nation associated with rain, perceptions of drought\... **[Drought monitoring]** Knowledge gaps needed in early warning from water resource perspective Technological developments in real time drought monitoring --crucial for agriculture and water resource planning and real time drought mitigation. Examples: - USGS - UK Centre for Ecology and Hydrology **Earthquake** Theoretical range of adjustments to [earthquakes]: Bear the loss (involuntary adjustment for most of human history and still the case in \'poor\' countries).\ Plan for losses (e.g. insurance and reserve fund).\ Spread the losses (e.g. public relief and subsided insurance).\ Modify the loss potential (e.g. warning systems; emergency evacuation and preparation; building design; land-use change and, permanent evacuation).\ Modify the hazard (e.g. stable site selection: soil and slope stabilisation; fire protection and sea barriers).\ Affect the cause (e.g. no known method of altering the earthquake mechanism). **Wildfire** **Fire severity mapping** 2001/02 fire in Sydney water supply catchment; remote sensing data from Chafer et al (2004). **Prescribed (or planned) burning:** (Agee and Skinner, 2005) - Prescribed burning was massively expanded following the 2009 'Black Saturday' wildfire in Victoria: increase in target burn area from 100,000 to 385,000 ha per year. - contributing to the recent occurrence of more higher severity wildfires EXAMPLE: **(**Boer et al., 2009) - Sydney suggests that to achieve a reduction of 50% in the risk to people and property requires treatment of 7-10% of the forest area per year (Bradstock et al., 2012). **Fire suppression comprises two main approaches** 1\. Direct attack: wetting and smothering; fire truck and aerial attack; but water resources are limited in forests. 2\. Indirect attack (primary methods): Backburning: lighting of fires to burn back towards an approaching wildfire to contain the wildfire Control lines or firebreaks: machinery or hand tools are used to clear forest fuels to limit fire spread. Reliance on large numbers of volunteer firefighters [Public safety:] 1. 'Stay or go' policy in Australia: 2. Evacuation: 3. Fire Danger warnings (e.g. Aust.): [Land use planning (before/after)] **(Gill and Stephens, 2009) (Harris et al., 2011) (Buxton et al., 2011)** **PREDICTION** **Volcanic Hazards** General Prediction: (also known as hazard mapping and assessment) - based on studies of past behaviour of a volcano so as to determine the frequency, magnitude and style of eruptions, type of damage and delineate high risk areas Specific Prediction: - is based on the surveillance of a volcano, and monitoring of changes - (e.g. in seismic activity, ground deformation, thermal characteristics and geochemistry of gases), to forecast the time, place and magnitude of an eruption. - High failure and no scientific Hazard Maps: - 2 groups: background or crisis - Types: geology, modelling, integrated qualitative - Users: locals. Tourists, media, NGO's, insurance and government. **Modelling (Spence *et al.,* 2005)** EXPLORIS - a\. Multi-hazard, multi-vulnerability impact model - b\. Incorporates all possible geo-referenced - c\. Feeds directly into mitigation policies. Problem: some aspects of a hazard and particularly vulnerability can not be geo-referenced. **Monitoring and Forecasting** **Instrumental:** - tracking the location and type - observing volcanic activity using webcams and thermal imagery - measuring the deformation of the ground surface [Forecasting and early warning systems] - forecast the onset of an eruption and track - challenge: determining if an episode of unrest is going to culminate in an eruption. Examples: 4 level volcanic alter scale - Evacuation from Mount Pinatubo 1991 - Mount Pinatubo 1991: temporary shelters [Global monitoring] Volcano Observatories (VO) - Globally there are over 100 VOs to monitor \~1551 volcanoes considered to be active\ or potentially active. - responsibilities of a VO differs from country to country **Wildfire** - Models also used to assess the effectiveness of different firefighting strategies as well as for planning prescribed burning operations. \- Weather-based statistical approaches for forecasting fire risk several days to one week in advance (e.g. Forest Fire Danger Index). Also used with climate simulations to estimate future fire risk. \- Computer models of fire behaviour: simulations of fire behaviour using relationships between key variables (fuel, slope, wind, RH, temperature) to model fire intensity, direction and rate of spread. EXAMPLE: **Forest fire danger index (FFDI)** FFDI; (Noble et al., 1980) **MODELS AND THEORIES** **Marginalization theory:** - disasters in developing countries arise from the (pre-existing) marginalisation of different sectors of societies rather than the hazard itself. **The implications of the marginalisation theory** (Susman *et al.,* 1983) **Implication** **Remarks** ----------------- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **1** In economically less developed countries, disasters will increase as socio- economic conditions and the physical environment deteriorates. **2** The poorest classes will continue to suffer the most losses. **3** Relief aid, which reflects dominant interests and prevents political upheavals, generally works against the classes who have suffered most in disasters. **4** Disaster mitigation based on high technology reinforces underdevelopment and increases marginalization. **5** The only way to reduce vulnerability is to concentrate disaster planning within development planning, and that the development planning context must be, broadly speaking socialist. **6** Because of the continued forms of exploitation, especially in underdeveloped countries, the only models for successful disaster mitigation are those conceived in the struggle against exploitation **[Brunn rule] (Brunn, 1988)** Sediment eroded upper beach = sediment deposited on the nearshore bottom. - When the biophysical processes dominate islands tend to be high elevation and vulnerability to storms is reduced. - When effect of storms/sea level dominate island might become trapped in perpetual state of low elevation →no recovery Vulnerability and social factors and physical definitions Preparedness and mitigation and management strategies Prediction Climate change impacts on hazards - Tsunami - Volcano - Drought - Earthquake - Wildfire Comparative analysis or models and theories Timeframes and progression Integration of social and environmental perspectives Technological and policy advances **CLIMATE CHANGE** **WILDFIRES** **Effect of Climate Change** (Pechony & Shindell 2010) argue climate will outweigh direct human influence on fire (ignition and suppression). -- With climate change, the southern fire season is likely to increase into spring and autumn. **Linkages of Wildfires with Climate Change x** Climate change increases intensity and frequency of wildfires Caused by changes in temperature, precipitation, and the frequency and intensity of severe storms -- Increases in temperature, decreases in humidity Human factors of settlement expansion and increasing tourism to arid regions. **5. Human effects** (Bradstock et al., 2012) (Ryan et al., 2013) (Pausas and Fernandez-Munoz, 2012) An important source of ignition (arson, accident) Effect on forest fuel loads: -- Prescribed burning -- Forestry: harvesting, thinning, roads and firebreaks -- Fire suppression and prevention; particularly in the US, the Mediterranean and Australia **FLOODS** Climate change saw 10 countries and territories have severe flooding in 12 days [Pakistan Floods in summer 2022] - \>1700 fatalities, - \>33 millions affected 2021 - 24 hr rainfall totals -- 14-15th July 2021 Caused widespread flooding and \>200 deaths CRESTA the Insurance Industry Loss Index estimates the floods to have cost the industry \$11Billion **EXTREME EVENTS** **PDO (Pacific Decadal Oscillation)**  long-term climate pattern in the Pacific Ocean that fluctuates between warm and cool phases every 20--30 years **Marine heatwaves** - During a positive PDO phase, marine heatwaves in the Northeast Pacific are longer, stronger, and more frequent.  - This is due to warmer coastal sea surface temperatures caused by reduced cold upwelling and increased downward surface heat flux.  **Precipitation** - During a cold PDO phase, the North Pacific experiences an anti-cyclonic anomaly circulation that - leads to below-normal precipitation in the western US and above-normal precipitation in North China.  **Global warming** Positive PDO phases are associated with more rapid global warming, while negative phases are linked to slower warming.  **Droughts** Cold PDO events have been linked to severe droughts in the southwestern USA.  **Tropical cyclones** In South Korea, autumn tropical cyclones often produce heavy precipitation due to atmospheric instability. The PDO is made up of several factors, including: - The Aleutian Low: A semi-permanent area of low atmospheric pressure off the Aleutian - Islands Ocean memory: Anomalies that develop due to weather or El Niño/La Niña can get trapped at depth and re-emerge the following year - The Kuroshio Current: The Gulf Stream of the North Pacific Ocean, changes in the strength and location of which can impact SSTs in the western half of the North Pacific Oscillates between positive and negative phases, with the positive phase characterized by warmer-than-normal sea surface temperatures along the western coast of North America. The negative phase is the mirror image, with cooler than normal waters along the western coast of North America. **NAO (North Atlantic Oscillation) (+ and -)** large-scale atmospheric circulation patterns that affects the climate in a wide area, including Europe, North America, and Asia - The NAO is the difference in pressure between the Azores High and the Icelandic Low.  - The NAO index measures the strength of these pressure patterns, with positive values indicating a strong pressure difference and negative values indicating a weaker difference.  **How it affects the weather** The NAO affects the weather in many ways, including: - **Temperature**: Positive NAO values are associated with warmer conditions in the U.S. East and Northern Europe, and colder conditions in Southern Europe. Negative NAO values are associated with the opposite.  - **Precipitation**: The NAO affects precipitation patterns in Europe and North America. In the British Isles, a positive summer NAO is associated with drier weather in June.  - **Storms**: A strong NAO is associated with stronger, more frequent storms that travel across northwestern Europe.  - **Wind**: The NAO determines the strength of westerly winds across the Atlantic.