Phenomenon Floods and Drought
There are many pressures on water resources, including those arising from human activities. Additionally driving forces arise from the natural variability in water availability and climate change.Recent history has shown that extreme hydrological events as flood and droughts can create additional stress on water supplies essential for human and ecosystem health.
Climate change leads to increasing frequency of extreme weather events evident around the globe. Unusually high rain fall, which many scientists agree is due to climate change, is a significant cause of floods. On the other hand droughts are becoming longer, harder and more frequent.
Floods and droughts are the two important aspects of hydrological hazard. Floods usually result either from heavy precipitation (rain or snow) or from rapid snowmelt or glacier discharge (CliC). Droughts are caused by dry weather conditions in which evaporation exceeds the available surface water.
A flood is an overflow of water, an expanse of water submerging land, a deluge. Flooding and its impactsn are often influenced by a combination of natural factors and human interference. Floods are the most common natural desasters in Europe and, in term sof economic damage, the most costly ones. Major floods that used to happen only once in 100 years now take place every 10 or 20 years. Flooding can be disastrous. Houses can be destroyed, lives can be ruined, and wildlife threatened. Climate change is not the only cause of floods. Other ill-considered human activities play a key role as well. Upstream forests are able to soak up a lot of water, but if humans are destroying these areas, we increase the risk of floods.
A drought is an extended period where water availability falls below the statistical requirements for a region. Also drought is not a purely physical phenomenon, but an interplay between natural water availability and human demands for water supply. Since the demand for European water resources is increasing, also the pressure on water continues to grow and Europe is becoming increasingly vulnerable to the effects of periods without rainfall. Droughts are the prolonged absence of water in a specific area. Droughts kill a lot more people than floods because the effects are more prolonged. Droughts are always naturally caused, usually because changes in weather patterns greatly decrease the rainfall to an area. This is common in the southern edge of the Sahara desert, where there are usually extended periods of rainprovide the region with the water it needs for the year. However, it has become increasingly common for the rains to be very weak, or not come at all. A glaring example was a five year drought in the area from 1968-73. Today, the effects of global warming are seen as the Sahara expands due to these droughts.
Reducing the effects of flood and droughts (water disaster)
1. Disaster preparedness
The aim of disaster preparation is to be able to reduce the immediate mortality and morbidity with a better prepared, well equipped service. The preparation includes early warning systems for seasonal changes in climate, the ENSO, and risk of flood or drought, such as electronic information systems and satellites that can provide information over large regions and continents. Separate systems are needed to cater for the agricultural sector, cities and people in rural or remote communities. The public health infrastructure is particularly important for the immediate measures needed and for public information on reducing the health risks. Being prepared also means thorough disaster contingency plans, covering emergency housing, repairs, replacement of essential equipment and protection of the most vulnerable people in the community: the sick, the very young and the old. Improvement of water supply and sanitation systems is an important way of reducing the effects of a water disaster: countries with a good infrastructure for drainage and disposal of human waste and adequate water supply facilities have far fewer direct health problems during water-related disasters Sanitary inspections are an important tool to assess the water supply and sanitation facilities and these should be conducted systematically. The logistics of the predicted need for health and social services also need to be laid down in advance, including early warning systems to detect health effects. Planning should be on a regional, national and international level and include planning for climate change: as global warming and its water effects will increase the frequency of water disasters. Finally, public information and education can serve two purposes in preparing for disasters: ensuring early warnings to communities at risk; and giving information about how to conserve water and keep it safe from contamination.
2. Disaster mitigation
Once a disaster has occurred, or has been identified, all the measures in disaster preparedness will be needed and if not in place, outside help is probably needed. At the least, the mitigation efforts must include:
Emergency housing, especially after floods, but also if a drought has caused mass population movement in an attempt to find better water and food supplies.
Provision of emergency supplies of safe drinking water.
Emergency repairs to homes, drains and water supply and sanitation infrastructure.
Early warning systems to identify health effects and to detect rise in mosquito borne diseases, such as malaria, and diarrhoeal diseases, such as cholera. For such systems to be effective, a good public health information system is essential so that epidemiological trends can be monitored.
Both disaster preparedness and its mitigation require multisectoral cooperation and joint planning. Both need evaluation after a disaster to reduce the ill effects of later crises. While our world is never likely to be free of water disasters, there is much that can be done to minimise their health effects.
Climate change leads to increasing frequency of extreme weather events evident around the globe. Unusually high rain fall, which many scientists agree is due to climate change, is a significant cause of floods. On the other hand droughts are becoming longer, harder and more frequent.
Floods and droughts are the two important aspects of hydrological hazard. Floods usually result either from heavy precipitation (rain or snow) or from rapid snowmelt or glacier discharge (CliC). Droughts are caused by dry weather conditions in which evaporation exceeds the available surface water.
A flood is an overflow of water, an expanse of water submerging land, a deluge. Flooding and its impactsn are often influenced by a combination of natural factors and human interference. Floods are the most common natural desasters in Europe and, in term sof economic damage, the most costly ones. Major floods that used to happen only once in 100 years now take place every 10 or 20 years. Flooding can be disastrous. Houses can be destroyed, lives can be ruined, and wildlife threatened. Climate change is not the only cause of floods. Other ill-considered human activities play a key role as well. Upstream forests are able to soak up a lot of water, but if humans are destroying these areas, we increase the risk of floods.
A drought is an extended period where water availability falls below the statistical requirements for a region. Also drought is not a purely physical phenomenon, but an interplay between natural water availability and human demands for water supply. Since the demand for European water resources is increasing, also the pressure on water continues to grow and Europe is becoming increasingly vulnerable to the effects of periods without rainfall. Droughts are the prolonged absence of water in a specific area. Droughts kill a lot more people than floods because the effects are more prolonged. Droughts are always naturally caused, usually because changes in weather patterns greatly decrease the rainfall to an area. This is common in the southern edge of the Sahara desert, where there are usually extended periods of rainprovide the region with the water it needs for the year. However, it has become increasingly common for the rains to be very weak, or not come at all. A glaring example was a five year drought in the area from 1968-73. Today, the effects of global warming are seen as the Sahara expands due to these droughts.
Reducing the effects of flood and droughts (water disaster)
1. Disaster preparedness
The aim of disaster preparation is to be able to reduce the immediate mortality and morbidity with a better prepared, well equipped service. The preparation includes early warning systems for seasonal changes in climate, the ENSO, and risk of flood or drought, such as electronic information systems and satellites that can provide information over large regions and continents. Separate systems are needed to cater for the agricultural sector, cities and people in rural or remote communities. The public health infrastructure is particularly important for the immediate measures needed and for public information on reducing the health risks. Being prepared also means thorough disaster contingency plans, covering emergency housing, repairs, replacement of essential equipment and protection of the most vulnerable people in the community: the sick, the very young and the old. Improvement of water supply and sanitation systems is an important way of reducing the effects of a water disaster: countries with a good infrastructure for drainage and disposal of human waste and adequate water supply facilities have far fewer direct health problems during water-related disasters Sanitary inspections are an important tool to assess the water supply and sanitation facilities and these should be conducted systematically. The logistics of the predicted need for health and social services also need to be laid down in advance, including early warning systems to detect health effects. Planning should be on a regional, national and international level and include planning for climate change: as global warming and its water effects will increase the frequency of water disasters. Finally, public information and education can serve two purposes in preparing for disasters: ensuring early warnings to communities at risk; and giving information about how to conserve water and keep it safe from contamination.
2. Disaster mitigation
Once a disaster has occurred, or has been identified, all the measures in disaster preparedness will be needed and if not in place, outside help is probably needed. At the least, the mitigation efforts must include:
Emergency housing, especially after floods, but also if a drought has caused mass population movement in an attempt to find better water and food supplies.
Provision of emergency supplies of safe drinking water.
Emergency repairs to homes, drains and water supply and sanitation infrastructure.
Early warning systems to identify health effects and to detect rise in mosquito borne diseases, such as malaria, and diarrhoeal diseases, such as cholera. For such systems to be effective, a good public health information system is essential so that epidemiological trends can be monitored.
Both disaster preparedness and its mitigation require multisectoral cooperation and joint planning. Both need evaluation after a disaster to reduce the ill effects of later crises. While our world is never likely to be free of water disasters, there is much that can be done to minimise their health effects.
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