Disaster and Crisis Scenarios and How they Impact Sanitation Services

Disasters are serious disruptions to the functioning of an affected population that exceed its capacity to cope using its own resources. Disasters can be caused by natural, human-made and technological hazards, as well as by various factors that influence the exposure and vulnerability of an affected population. Emergencies arise in a range of contexts and can be either acute and time-limited or chronic and protracted. They may lead to disrupted services, significant losses and damage inflicted upon communities and individuals, including the potential loss of life and livelihood assets, leaving the affected population unable to function normally without outside assistance. 


The level of risk in a humanitarian disaster depends on the exposure and vulnerability of a population to a hazard. It only occurs where a population is exposed to the hazard (without exposure there is no risk) and where the affected population is inappropriately prepared, resourced or organised to withstand the impact of likely, imminent or current hazards.

Disasters or humanitarian emergencies can take different forms. Each emergency, depending on its scope, causes and context is unique and can have a significant impact on people, the environment, the infrastructure and, ultimately, on the provision of functioning sanitation services. Emergencies arise in a range of contexts and can be either acute and time-limited or chronic and protracted. Many hazards – particularly weather and climate-related hazards – occur fairly predictably in line with the seasons (e.g. at certain times of the year) or in specific, repeatedly affected regions. In these cases Disaster Risk Reduction (DDR), Preparedness and Mitigation measures (DRR and Resilience Strategies) can help to better anticipate, respond to, lessen the impact of and aid recovery from hazardous events.


The scenarios leading to emergencies can be broadly categorised as follows:

Disasters triggered by natural or technological hazards: natural physical hazards include: (1) geophysical:  originating from solid earth such as earthquakes, landslides and volcanic activity, (2) hydrological: caused by the occurrence, movement and distribution of water on earth such as floods and avalanches, (3) climatological: relating to the climate such as droughts and wildfires, (4) meteorological: relating to weather conditions such as cyclones and storms, or (5) biological: caused by exposure to living organisms and the toxic substances or diseases they may carry – such as disease epidemics and insect/animal plagues. These natural hazards can cause humanitarian disasters claiming many lives and leading to economic losses and environmental and infrastructure damage. Due to the far-reaching impact of climate change, humanitarian assistance increasingly has to deal with extreme weather events and their consequences.

Technological hazards arise from technological or industrial conditions, dangerous procedures, infrastructure failure or human activity. They include dam breaks, industrial accidents, transport accidents, or chemical, biological or nuclear contamination. The continued growth of the world’s population, global urbanisation and changes in land use further increase people’s vulnerability to natural and technological hazards. Such disasters often result in a deterioration of environmental health conditions, particularly in access to basic sanitation services. Infrastructure such as roads (e.g. for faecal sludge transport), sewerage systems, treatment facilities, water supply as well as toilets and washroom facilities are often directly affected, reducing access to sanitation and relevant hygiene behaviours like handwashing. As a result, the risk of water and sanitation-related diseases increases.

Conflicts: refer to societally created emergencies such as political conflicts, armed confrontations and civil wars. Critical infrastructure (such as fully or partly centralised faecal sludge or wastewater treatment facilities) can become a target. Conflicts often lead to displacement. Many internally displaced people (IDP) or refugees have to be housed in camps, temporary shelters or host communities, where access to adequate sanitation and hygiene is required at very short notice – and often maintained over long periods. The majority of displaced persons are absorbed by host communities. This can overburden the existing sanitation infrastructure and make it difficult to identify and quantify actual needs; upgrades to existing infrastructure may be required. If people are displaced in large numbers, community structures and support mechanisms are often disrupted; response plans may need to support community reorganisation. The complexity of a conflict’s dynamics can make it difficult to plan how long shelters and the corresponding sanitation infrastructure must remain in place. The duration can vary from a few weeks or months to several years or even decades. As a result sanitation services may have to be incrementally adapted to changing circumstances (from temporary/acute to more sustainable long-term solutions). In addition, refugee camps are often constructed in places where there is already tension about the sanitation situation. In locations where refugees are initially housed in temporary shelters or a camp, it is usually politically undesirable to plan a permanent settlement. Local decision-makers may oppose activities viewed as making the settlement more permanent or better developed for fear of encouraging the refugee population to remain instead of returning home. Additional challenges arise if the conditions in the camp become better than those in the host communities, creating tension between the local and refugee populations. Such cases should be seen as opportunities to improve WASH services for both host and refugee communities.

Fragile States and Protracted Crises: states can be considered fragile if the state is unwilling or unable to meet its basic functions and services. The safety of the affected population may be at risk as basic social services are not, or are only poorly, provided. Weak government structures or a lack of government responsibility for ensuring basic services can lead to increased poverty, inequality and social distrust and can potentially develop into a humanitarian emergency. Protracted crises are characterised by recurrent disasters and/or conflicts, prolonged food crises, deterioration of the health status of people, breakdown of livelihoods and insufficient institutional capacity to react to crises. In these environments, a significant proportion of the population is acutely vulnerable to mortality, morbidity and disruption of livelihoods over a prolonged period. The provision of basic sanitation services is frequently neglected and external support using conventional government channels is often ineffective. Under these conditions, it may be necessary to explore complementary and alternative means of service provision, basing it mainly on more decentralised non and sub-state actors.

(High-) Risk Countries Continuously Affected by Disasters and Climate Change: many countries face enormous challenges from climate change and the increasing likelihood of associated natural hazards. The risk that natural events will turn into a disaster is largely determined by the vulnerability of each society or group, the susceptibility of its ecological or socio-economic systems and by the impact of climate change both on occasional extreme events (e.g. heavy rains causing floods or landslides) and on gradual climatic changes (e.g. temporal shift of the rainy seasons). Climate change also exacerbates problems in countries that are already suffering from disasters. Sanitation interventions require a strong focus on preventative Resilience and DRR measures (DRR and Resilience Strategies). Existing sanitation infrastructure may require adaptations or the introduction of more appropriate and robust sanitation systems to increase resilience and help communities cope with climate-induced recurrent extreme weather events (e.g. raised sanitation solutions for flood-prone areas, the introduction of waterless sanitation systems in water-scarce areas or the introduction of reuse-oriented sanitation solutions to support local food security). In addition, sanitation systems may need adapting to serve climate change refugees and IDPs.Disasters can be a mix of several categories (e.g. a fragile or conflict-affected state also affected by a natural disaster). This makes response targeting more difficult (deciding for example whether to target those affected by the natural disaster or those affected by chronic conditions). Disaster and crisis scenarios can also be sudden onset (e.g. earthquakes or conflicts) or slow-onset (e.g. droughts that may lead to a prolonged food crisis) or fragile contexts that lead to a deterioration of services over time. Depending on the type of crisis, the population and infrastructure may be affected very differently. While some disasters lead to massive population movements (with implications for a comprehensive public health response) others may only affect the infrastructure (shifting the response focus to repairs and respective improvements).

Author(s) (1)
Rob Gensch
German Toilet Organization (GTO)
Reviewer(s) / Contributor(s) (2)
Shirish Singh
IHE Delft Institute for Water Education
Thorsten Reckerzügl
German Toilet Organization (GTO)

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