17 Problems of Flood and Drought

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Introduction

 

Water is an essential resource for survival of life, however excess of it can cause calamity and lack of it can cause disaster. Excess of water than required can cause flood and on the other hand water deficit can cause drought. Flood and drought are extreme negative situations caused due to water imbalances. These disasters though mainly natural have substantial human intervention triggering the impact. Flood and drought have occurred in the past as well, but its frequency has increased in the recent years due to changing climatic pattern. Floods and Droughts have huge impact on earth and lives and deaths of living communities.

 

Flood Situation

Source: Taranaki Emergency Management, New Zealand.

 

Drought Condition

Source: Livemint E paper.

 

Natural disasters including floods and droughts can strike any part of the world but evidences shows their impact is disastrous in developing countries than the developed one’s, mainly due to the availability of their advanced warning system and proper disaster management system. For instance as per report from ((Centre for Research on the Epidemiology of Disasters (CRED, 2004)), USA has faced maximum number of disaster events including typhoons and floods (506 reported events) between 1974-2003, with 4.5 millions victim, whereas India experienced 303 disaster events during the same period but the number of victims was much higher approx 1932 million people.

 

Flood happens when water quantity of any region exceed the normal requirement level damaging the physical, infrastructural, economic and social set up of the affected area. Heavy rainfall mainly causes flood in an area when the natural watercourse fail to channelize the excess water. When the banks of the river fails to contain the heavy flow of water due to heavy rainfall, inundation occurs; even high storms during tsunamis or cyclones can cause inundation near coastal areas. Places without proper drainage system also get flooded during heavy rainfall.

 

Drought is also an extreme situation, which happens due to insufficiency of precipitation over a longer period causing damages to crops. Definition of drought varies in different countries and regions depending on the average precipitation level of the country such as countries or regions generally receiving lesser annual average rainfall don’t consider 5 to 6 days without rainfall as drought however similar condition is called a drought situation in countries receiving higher rainfall throughout the year.

 

Causes of Flood

 

Flood can cause due to any of the following or combination of the following reasons:

Source: Office of Queensland Chief scientist, Queensland, Australia.

 

http://www.chiefscientist.qld.gov.au/publications/understanding-floods/what-factors-contribute

 

Excessive Precipitation: Heavy precipitation or rainfall in an area than normal along with poor drainage system can cause flood like situation. Flood can occur in both cases of heavy rainfall for shorter duration and continuous light rainfall for many days.

 

River Runoff: Excessive supply of water in the upstream due to heavy rainfall or otherwise can cause the downstream river water to run into the land or flood plain areas causing inundation.

 

Strong Coastal wind or Cyclone or tsunami: Strong coastal winds have the capacity to carry water from the sea to the land causing inundation in the coastal areas. Besides, Cyclones and strong winds can also bring heavy rainfall, causing flood on inland areas as well.

 

Breakage of Dams or Embankments: Embankments or levees are built alongside the river to prevent overflowing of water or avoid flood like situation on the adjoining land. However breakage or leakage on the embankment can lead to overflowing of river water on the flood plain also heavy water flow can break embankment and cause flood. Similarly dams, which are built to capture water flowing down from upland can cause floods if broken due to excessive pressure of the stored water, even at times extra water from dams are knowingly released to avoid possible breakage or leakages, which can also cause flood like situation in the lower lands.

 

Breakdown of Ice dam: Ice dams occurs when glaciers or ice blocks restrict flow of river water during freezing weather. This stored water behind ice sheets/ blocks or proglacial lakes when released due to ice melting is more powerful than normal river water flow and can cause inundation at the lower catchment areas. e.g The Flood in Russel Fjord in Alaska USA in 1986 caused due to breakage of Ice dam.

 

Volcanic Eruptions: Volcanic eruptions has caused floods in country like Iceland where volcanic vent covered by thick layer of ice/ glacier got melted due to emission of hot lava. The melting glaciers turns into fast flowing water down the steep volcanoes causing inundation in the nearby areas.

 

Types of Floods

 

Broadly floods can be classified as per timings:

 

Flash Floods: Flash Flood appears very fast and due to its sudden arrival, the term flash has been added to this types of flood. Flash flood cover smaller area but with high intensity, usually due to heavy rainfall or breakdown of Ice dams. Because of its higher speed and sudden appearance this flood causes more damages and is dangerous. Flash flood can even transport heavy rock, boulders and other heavy items due it its high speed. Besides, its capacity to carry debris makes this flood more dangerous as can damage both life and property.

 

Source: European Commission

 

Slow on-set Flood: This type of flood last long and spread over larger areas and occurs mainly due to over flowing of rivers or other water bodies. Since many coastal areas and flood plains repeatedly get inundated during rainy seasons, people for safety moves up to higher grounds during this period. The after effect of this flood is more dangerous as people die due to diseases and famine.

 

Source: Indian Express

 

http://indianexpress.com/article/india/india-news-india/chennai-floods-rains-jayalalithaa-imd-reasons-rescue-news-updates/

Rapid on set Flood: This type of flood occurs fast and last for a shorter period almost for a day or two. This flood is associated with heavy rainfall and as it appears fast the chances of damages to property and life are high as people get less time to prepare before the flood appears.

Source: European Commission

 

The other types of floods are:

 

Ice Dammed Flood: Ice Dam Flooding happens when flowing water, which were initially restricted by block of ice flow again due to melting of ice or spilling over of the piled up water above the ice wall into the nearby plain areas. This flowing water is more powerful and dangerous than simple flowing river as this water carry big pieces of ice and thus with flooding of the plain area, this ice loaded water can damage property and life.

 

    Coastal floods: This is a common type of flood in coastal areas. This flood is caused by high storms and waves in the oceans and mainly the area near the ocean edges get inundated. Even Tsunamis, cyclones, hurricanes and tornadoes with low pressure center, which pulls the water from the ocean towards the center of the storm carries the dome of water while moving towards the landand when reaches the coast this water loaded storm causes flooding and resultant damages. Even fast moving waves or storms are destructive at times breaks past beaches and causes flooding at the coastline.

 

Storm surge Flood: This is more devastating than the coastal flood as the storm rises above the normal high tides mainly due to strong winds and lower atmospheric pressure. Storm surge causes huge damages to large areas near the coasts. These storm surges up to a height of 20 feet or more. Major hurricanes with huge storms have caused damages to property and life in the past including the recent past, where hurricane Katrina caused huge damages along the gulf coast in Texas and state of Florida.

 

Breakage of Weakly constructed dams: Over filling up of dams can break the walls of the dam when weakly constructed and cause flash floods in the downstream regions.

 

Areas Prone to Flooding

 

In areas where drainage is not properly built and maintained, little extra rain than normal can cause flooding. For instance many cities in India like Delhi experience flooding during monsoon when precipitation is little higher than normal mainly due to lack of proper drainage or its maintenance.

 

Besides, any area of a city or a village can get flooded if rainfall is higher than the capacity of the drainage system to absorb the extra water.

     Areas Prone to Flooding in India

 

The areas where river water flows from higher level to low lying areas, the chances of inundation in the lower region is high during heavy rainfall or due to breakage of dams, when extra water is added to the river. Also, encroachment in catchment areas and flood plains along with depletion or lack of vegetation increases the chances of flooding. Flood plains are productive land with good quality soil, hence are often used for agricultural and other economic purposes and are densely populated. During heavy precipitation the catchment areas receives heavy rainfall, the additional water then enters the densely populated catchment areas causing heavy damages. In India, states like Orissa, Andhra Pradesh, Bihar, and West Bengal are prone to flooding. Banks of river Ganga and Brahmaputra also often get flooded. In countries like Bangladesh flood disaster also is a regular crises, due to lack of proper drainage and densely populated catchment areas along many river banks.

 

Impacts (Problems) of Flooding

 

Floods are destructive and have its impact on Economy, environment and human life.

 

The economic Impact of Flooding: Floods like flash flood, storm surge causes huge damages to properties and infrastructure of the affected areas. Houses, bridges, farms, roads, electric poles and vehicles are mostly destroyed causing huge economic losses to both public and government. Many people losses their livelihood due to floods impact on agricultural fields, industries etc. Due to damages in communication lines, infrastructure and transport networks business takes hit not only in the flood affected areas but also in the adjoining localities. The long time after effects of flood are felt in terms of lack of clean drinking water, disruption in power supply, reduction in purchasing power of people due to loss of income, rise in prices of basic items etc. Even rebuilding the infrastructure, rehabilitation of people and bringing the normalcy in economic activities takes lot of time causing further economic losses. For instance, the flood in Chennai, India in November 2015 is estimated to have caused $3billion losses. As per estimation by NOAA the flooding in 2011 in USA caused a loss of about $ 8.41 billion. Besides if floods occurrence are regular many people and business moves out of the place leading to mass migration, development in these places cripples as government and private business fear of similar devastations in future due to recurring nature of flood. The following table shows the impact of flooding on India’s GDP.

 

Percentage of Loss in GDP due to Flood in India

 

Decade % share
1953-1960 0.45
1961-1970 0.46
1971-1980 0.86
1981-1990 0.86
1991-2000 0.33
2001-2010 0.31
2011-2016 0.11

Source: Central Water Commission

 

Environment Impact of Flooding: Flooding has its impact (both negative and positive) on the environment. Unlike the economic impact of flooding, which is mainly negative, flooding has some positive impact on environment. Such as refueling of surface and ground water storage. This replenishment of water supply helps in improving the soil quality and thus crop production. But the negative impact of flooding on the environment is quite dangerous as the flood water brings along with it different types of pollutants, chemicals, debris including uprooted trees, stones etc. This polluted water contaminate the clean water due to breakdown of water pipes and drainage systems. Besides, due to flooding many animals loses their natural habitats and contaminated water impacts the health of livestock as well as wild animals. Reduction in biodiversity level happens due to death and displacement of many animals during and after flood. As noticed in Australia’s Queensland in 2011, where heavy flooding resulted in death of many animals. The flood water once receded leave behind debris and sediments, which also hampers the water quality.

 

In 2011, Tsunami struck Japan and many coastal areas got flooded including the Fukushima, where waves caused level 7 meltdown of the power plant and release of radiations due to cooling system failure by Tsunami. Nuclear radiation release has long term negative impact on the health of people, animals and the environment.

 

Impact of Flooding on human and animal: The direct impact of flooding is experienced maximum by humans and animals. Flash flooding or sudden arrival of huge floods causes many damages to people and animal including loss of lives and properties. Many animals and people are forced to migrate to safer places. Post flooding rise in diseases also impacts human and animals badly. Many people becomes homeless due to flood havoc. In addition to the physical impacts people also suffers psychologically. The flood victims can remain traumatized for longer period of time as they see all the devastation in front of their eyes. Also, by losing home and other properties the security level of people decreases they become vulnerable to many threats. The stress to rebuild the life post devastations takes further toll on human’s life. The following table shows the loss of human and cattle life in India due to flood from 1953 to 2016.

 

Loss of Life due to Flood

Cattle lost Human lives lost
Decade (Nos) (Nos)
1953-1960 33771.9 439.1
1961-1970 50509.2 943.9
1971-1980 191928.7 2559.5
1981-1990 121582.9 1965.2
1991-2000 86830.6 1892.1
2001-2010 88432.9 1867
2011-2016 48707.8 1481.5

 

 

3. People should be advised to stay indoors as much as possible and not touch any open electrical poles or wires uprooted or damaged due to floods.Source: Central Water Commission

 

Precautionary Steps before Flood

 

Floods have now become a regular natural hazard mainly due to changes in the climatic conditions. Now not only coastal areas but even urban areas and cities are getting flooded often due to sudden outburst of heavy rainfall and lack of proper drainage to absorb the additional water. Thus flood preparedness by both government and public is required. Following are some of the steps that can be taken to avoid the devastating impact of floods.

 

 

1. Proper warning system need to be established and locals and concerned authorities need to be warned in advance about any impending natural calamities. So that flood impact precautionary measures can be taken on time.

 

2. Unauthorized illegal encroachment on river catchment areas should be stopped to avoid flood risks.

 

3. Local authorities need to prepare an evacuation plan and share the same with the residents of the area.

 

4. Neighborhood communities are the first one to respond to any disaster, hence people should be trained to handle rescue operation in flood prone areas.

 

5. The location of the relief centers and the contact details of relief centers needs to be made available to all.

 

6. In case of flood, emergency kit including basic medicines, first aids, food and water, battery powered radio to keep getting news about the disaster, extra cash, torch, mobile phone with charger, clothes and last but not the least photocopies of important personal documents needs to kept handy. Even sanitation items should be included in the emergency kit.

 

Steps to be taken during and post flood

 

1.During flood faster evacuation of people from impacted areas is of foremost importance to reduce the number of life risks.

 

2. People staying in the ground floors should move to higher floors with their important belongings.

  1. People should be advised to stay indoors as much as possible and not touch any open electrical poles or wires uprooted or damaged due to floods.

   4. Post flood relief measures should be immediately taken to avert higher risk of loss of life and property.

 

5. Search, rescue, relief and rehabilitation are four most important steps, which need to be promptly executed by communities and authorities to reduce the impact of flood.

 

6. Municipal communities need to ensure effected people are provided immediate medical help and counseling.

 

7. Rehabilitation of impacted people to safer and protected places should be done immediately to control disastrous impacts.

 

8. Law and order situation often goes out of order post disasters, hence police personal should be trained and properly equipped to handle any further causalities.

 

Besides, communities and people at large should be more considerate to each other and irrespective of caste, economic status or religion should come forward to help each other in the hour of crisis.

 

Flood Preventive Measures

 

Heavy precipitation cannot be avoided as it’s a natural phenomenon. However, preventive steps to avoid flood like situations if taken timely can save both life and money. Following are some flood prevention steps:

 

1. Well Built and Managed Drainage System: Proper drainage system should be part of town planning. A free flowing drainage system can absorb extra water supply during heavy precipitation and avert inundation. In flood prone areas houses built at higher level should be given permission to be constructed and blockage of drainages’ and waterways by illegal construction should not be allowed. Municipalities should ensure coverage of all drains to avoid littering and resultant blockage of drainage and resultant flood like situation.

 

2. Increase of Vegetation Cover: More trees, grasses and shrubs should be planted in flood plains to avoid soil erosion by flowing water. Excessive flow of water can be controlled by trees, hence plantation of trees should be made compulsory in coastal areas and near water bodies such as rivers, streams and lakes.

 

3. Building Sea walls and gates: In coastal areas, sea walls or tidal gates can be built to control high tidal waves from entering the coasts.

 

4. Building of Reservoir and small detention basins: In areas where flood is recurring phenomena construction of reservoirs and dams on rivers can be done. Smaller natural detention basins or depression can also be built at rivers to drain extra flood water during the beginning of floods and give time to people to evacuate before heavy floods. For instance ‘beel’ or depression on the banks of Brahmaputra in Assam is built to capture overflowing river water.

 

5. Spreading Awareness: People need to be educated regarding flood’s do’s and don’ts.

 

People should be educated about the reasons of flooding and how the devastating impact of this natural calamity can be controlled.

 

NATURAL DISASTERS (FLOOD AND DROUGHT) AND THEIR MITIGATION STRATEGIES

Source: Compiled by Author

 

Drought and its Causes

 

If flood happens due to excess of water than drought due to lack of it and dryness and resultant lack of agricultural production leads to drought situation. The major causes of drought are:

 

Lack of precipitation: When the level of precipitation is less than about 75% of the normal average, over a long period of time, drought happens. The drought condition is more prevalent when agricultural production gets impacted due to lack of rainfall and irrigation facilities.

 

Reduction of surface water flow: When the flow of surface water bodies like streams and rivers reduces or the rivers get dried up due to storage of water in dams/ reservoirs in the upstream for hydro power plants and irrigation facilities, drought like situation happen in the downstream regions of the river

 

Deforestation: Hydrological cycle (including evaporation, precipitation and condensation) of the earth is maintained by plants and trees. Trees have water retention capabilities, can control evaporation and maintain ground water level. Deforestation due to excessive population growth and various economic activities has exposed the surface to erosion and reduced the level of ground water and the ability of the earth surface to hold water, as a result with prolong period of dryness, desertification and drought crises appears.

 

Global Warming: Rise in global temperature due to increase in greenhouse gases has impacted the climate drastically as a result many areas goes dry and forest catches fires leading to desertification and drought like condition.

 

Areas Prone to drought in India

 

Drought has become a recurrent phenomenon in many parts of the country due to less precipitation. In the given map, the probability of occurrence of drought and drought prone areas of the country has been shown. Any region receiving less than 75% of the normal precipitation can be considered as drought effect area.

Source: Yourarticle Library

 

Types of Droughts

 

Droughts conditions can be classified as agricultural, meteorological, hydrological and socio economical drought. The drought condition act as indicators for government agencies, authorities and municipalities to develop a relief plan and provide related assistance to effected public.

 

Agricultural Drought: This drought condition impacts the country’s economy drastically. Farmers are badly effected with agricultural drought when soil moisture decreases and water demand for crop production surpasses the water supply level impacting crop growth. Decline in crop growth and production ultimately hampers the food supply and economy. Agricultural drought condition happens when the soil moisture reduces due to hot and dry weather with less rainfall leading to lack of agricultural production.

 

Source: The Hindubusinessline.com

 

Hydrological Drought: This is a drought condition where in the water level of all the surface water bodies including dams, lakes, reservoirs, rivers etc. falls below an established standard. Even when demand or usage of water is more than the supply or availability of water in the reserves hydrological drought happens.

Meteorological Drought: This drought condition is due to natural factors like lower level of precipitation, lack of moisture in the atmosphere, dryness for longer period and high temperature. Meteorological drought if persist for longer time period can cause serious water crises and related problems. This drought can stretch from a small period to longer period.

 

    Impact (Problems) of Drought

 

The impact of drought can be felt beyond the physical boundary of drought hit areas. As drought condition is associated with lack of water, it impacts not only the society but also the economy and the environment.

 

Economic Impact of Drought: Water is required for production of goods and service, thus lack of it impacts people, business and governments. Water is prime factor for agricultural and related field, crop production largely depends on the water supply, and hence shortage of it hampers production of both crops and livestock’s. Farmer’s or crop producers bear the brunt directly as lower crop production means direct loss of profit margin and income. Loss of income mainly of the farmer impacts their social life. Lower production and higher demand for food supply can lead to price rise of basic commodities, which have direct impact on the buyers especially the lower income group. Also, in case of shortages of basic commodities, things might be imported, again costing the government. Business might take a hitting if drought conditions persist for a long time such as most manufacturing industries, agricultural product industries, and water recreational business depends on water, so lack of it can force the business to stop operation in the affected areas. Thus many people can become jobless.

 

Besides, drought condition and associated dryness also increases the chances of wind erosion and birth of various diseases and epidemics as well, which costs individuals, community and the nation at large.

 

Lower precipitation, high temperature and dryness increases the chances of forest fires, which damages the habitat for both animal and human. Forest fire and damages to plants and other vegetation impact both public and the government.

 

In addition, shortage of water or dryness of the surface water like rivers can impacts hydro power generation as well as transportation through waterways.

 

Social Impact: Drought has its direct impact on the people and the society and many indirect long term impact. For our basic daily activities including cooking, eating, bathing and cleaning we need water, thus its shortage or lack of it can directly impact our lives.

 

Water is directly related to our health as well, we need clean and fresh water for drinking and cooking. Polluted and stale water can cause serious health implications and spread diseases across the society.

 

Due to lack of water supply agricultural and live stocks production takes a hitting causing lack of food production. When the supply is low the price rises impacting the poor people of the society most. Without proper watering of plants the quality of food also reduces and so does the nutritional values of the food. This lower quality food supply affects health of both human and animal and makes them vulnerable to diseases and health issues.

 

If drought conditions persist people prefer to migrate to other places leaving their property and at times their families. Many farmers in case of agricultural droughts have to leave their farms and take up odd jobs in other areas or towns.

 

Water, its supply and shortages have triggered many disputes between nations, states and neighboring people. For instance, in India disputes between states regarding water is not very uncommon like Kaveri river water dispute between Karnataka and Tamil Nadu, Yamuna water usage issues between Delhi, UP and Haryana etc. these disputes causes social unrest.

 

Environmental Impact: Drought like conditions impact the environment drastically. If the rivers, streams and other water bodies do not get fresh water supply through precipitation or melting snow the ecosystem of such aquatic bodies can be drastically impacted. Many water borne organisms and animals dies due to lack of water supply. Lakes, Ponds and rivers, which get replenished with fresh rain water might also die if shortage of precipitations last for longer period. Soil erosion due to high temperature and dryness can remove the productive top soil leading to lower biological production and land degradations. Many animals and organisms loses their habitat threatening their extinctions.

   

Drought Mitigation and Management

 

Drought is a natural hazard that cannot be stopped from occurrence but its affects can be minimized with proper planning. Drought conditions takes time to evolve hence precautionary measures can be taken to minimize the risk of drought devastations.

 

Predictions, observations, impact analysis and reaction are four major components of drought preparedness. Predictions about the impending climatic conditions and precipitations based on remote sensing data, satellite imageries, wind circulations etc. and proper monitoring of cloud movements, water availability and conditions of the crop are necessary steps of drought preparedness. Impact analysis of drought includes the study of crop quality, human health, state’s economy and ecosystem. The response of drought include providing relief to effected people, water storage facilities to all, water and soil conservation, more vegetation and proper planning. Following are some of the major steps to prevent drought like conditions:

 

1. Education and Awareness: People should be educated and informed about the causes and impacts of drought in advance. Community leaders, NGO’s, schools, Colleges, government officials etc. should be trained to educate general public about ill effects of drought and steps to mitigate it. Knowledge about the problem can help the public to create their own solutions. People in the governing authority should also gain knowledge about the climatic conditions and regional landscapes so that natural disasters like drought does not take them by surprise and policies can be defined well in advance to tackle any such unwanted situation.

 

2. Pollution Control: In case of shortage of natural water supply through precipitation and meteorological drought conditions people depend on the available water resources such as rivers, lakes, ponds etc. for clean usable water. However, if these surface water or ground water resources are polluted then problem escalates. Hence, government should ensure that the surface and ground water sources are not polluted. Even people should be educated about the problems of drought and the need for maintenance of clean water and control of pollution.

 

3. Water and Soil conservation: Water conservation and soil conservation measures can help in limiting the devastating impacts of drought. Water conservation methods such as rainwater harvesting, surface runoff water collection, percolation ponds, proper planning of water usages, dams and reservoir construction and proper management of well and water channels limits the impact of meteorological drought conditions. Similarly through soil conservation methods soil moisture can be retained and soil erosion can also be controlled during drought period. Methods such as crop rotation, terrace farming, etc. control soil erosion and soil moisture can be retained by measures such as furrows, basins, ridges, catch pits etc., even landscape contouring where the runoff water can be directly spread in planted areas helps in increasing the soil moisture content.

 

These mentioned steps can control drought conditions and its disastrous effects.

 

Conclusion

 

To sum up, it can be said that the problems of drought and flood are not only nature’s creation but human intervention aggravate the disastrous impact of these natural calamities. Hence, the solutions to control these problems also lie with human. Conservation of natural resources by controlling misusages can prevent many natural disasters. Public awareness and proactive initiative by governing authorities can reduce the impact of associated problems of flood and drought.

 

you can view video on Problems of Flood and Drought

 

References