A drought is a meteorological hazard, caused by a prolonged period, receiving below average levels of precipitation, than is usual in that place at that time. Droughts are often hard to predict, which can result in the effects being more severe. Droughts can reduce agricultural production, sometimes destroying crops; they can also cause severe harm to humans. When the rain returns it may take some time for water levels to get back to normal, which means that drought conditions can continue despite the rain, a bad drought may last several years and make the land completely infertile.
In depth, there are several causes of droughts; some happen together, others take place alone; however all result in a drought, no matter how severe. One of the causes of a drought is a change in the jet stream, the normal pattern, which occurs throughout the year, is disrupted and causes unusual weather, these results in certain areas receiving less or more precipitation than they usually would at that time in the year. A second cause is unusual high pressures in the atmosphere; moisture evaporates due to warm air rising, this causes less clouds to be made, which then can’t hold much rain due to the smaller number of them, this leads to lack of precipitation.
Another cause is the change in ocean currents, this links with climatic disturbances and trade winds, which are caused, by El Nino and La Nino, changing temperatures across the world, these commonly occur in California, Australia, Chile and Indonesia. Yet another cause of drought can be due to the low levels of moist oceanic air found in mid-continental areas, this is basically down to the distance of the location from the ocean, an example of this is the Gobi Desert. Another cause of drought is when prevailing winds travel across the continent, moving dry air towards the coast, making them drier than expected, because the air is coming from interior the coast. The final cause of droughts, is down to the human race, and their lifestyle demand for extra water to fulfil their needs, this puts extra pressure on supplies.
The great Drought of China during 1876-1879 was one of the deadliest droughts in the worlds recorded history; no food at all could be grown on 386,000 square miles of farmland across nine provinces of northern China. Rivers were dry, so most crops and livestock died. An estimated nine million people died. Within 3 years the harvest failures resulted in an increase of the price of rice to 5-10 times that in a normal year, the total population of the affected areas or North China decreased by more than 20 million due to deaths and migration. Related investigations have shown hat the drought was linked with a strong case of El Nino.
In the USA during the 1930’s there was also a large episode of drought, the drought came in three waves, 1934, 1936, and 1939-40, but some regions of the High Plains experienced drought conditions for as many as eight years. It affected 150,000 square mils of the Great Plains. Farmers overworking their land, removing the grasses that held the soil in place, caused the ‘dust bowl’ effect. As the land dried out, the soil blew away creating violent dust storms. It triggered the largest migration in the nations history putting 2.5 million people on the move as farming family were forced to abandon their land. A third example of a major drought is that in England between the years 1276-1305. It first began in 1276 with a very hot, dry summer. Food prices increased and in some years farmers could not produce any hay. The summers of 1289 and 1294 however were unusually wet this led to many animals dying from starvation in 1305.
When a drought occurs in any location, the environment is always affected, in some way. Environmental losses are the result of damages to animals, plants, wildlife habitats and overall land quality. There can be direct and indirect effects caused by drought, for example the lack of water will mean that crops will die, this is the direct effect had. Because of the lack of crop production, a famine can be caused, and people will die due to the lack of food, which is able to grow, this is an indirect effect it could cause. The damage drought cause to animals, is major, animals rely on certain sources of water to keep them alive. The increased desertification has major damage on the many different animal species, livestock numbers will decrease due to the decrease in water available and the increase in water cost, so their owners cannot afford to provide them with water.
Other animals, living in the wild will die, also due to the lack of availability of water, this result in high livestock mortality rates. An example of animals affected by drought, is frogs, as they need water to lay their eggs in, and then for the tadpoles to survive in as they develop. As many creeks, rivers and wetlands dry up, certain species may not breed during the effected time zone of the drought, leading to a disruption of the reproductive cycles, this is a direct impact drought creates. Another case is the reduction of the population count of fish and other aquatic organisms due to the decreased flows, another cause for the death of living things in the water, in earlier stages of the drought, the fish and other water organisms, could migrate from one area to another where more water is found.
This would result in a higher population of living things in a certain space; this causes issues, as there will be competition for food and space. This is also the case for land and air animals, the migration and then concentration creates loss of wildlife in some areas which can lead to the loss of biodiversity, and too many animals in other areas. Either scenario, too many or too little, causes problems for other animals both meat and vegetation eaters. In areas of a high count of biodiversity, the animals which rely on plants are their source of nutrients, will face competition as many others will also be relying on the same thing. In areas, which have suffered the loss of animals due to migration, those who eat meat, such as birds of prey will suffer, as many of the animals, which they would eat such as mice, will have moved elsewhere. When animals face death due to lack of water, this is a direct effect of drought, then they migrate elsewhere and when other animals suffer threat of death, are both indirect effects as they occur due to the lack of water in the first place.
Another cause of death in animals is when they venture onto farmland, to eat the crops, however farmers become less and less intolerant with intrusion, and will kill the animals. Consequent to the deaths, the spread of disease is large, and results in many other deaths, some carcases dry out due to the intense heat before they have a chance to decay. Not only do the Insect infestations can also occur, due to rotting animals and also the rotting crops. Diseases occur in plants, which are suffering from drought, because of the hot days and cold nights, dew forms on the leaves of the plants causing humidity, which leaves them exposed to diseases. As the amount of effected plants increases, as does the insect count, they can spread the disease to other plants, which are not yet infected. This outbreak in plant disease, can also affect trees and shrubbery, in which some animals may rely on to eat as food. The death of crops die to lack of water is a direct impact, as it wouldn’t have happened if there was a normal supply of water, the insect infestation and spread of disease are both indirect effects of drought.
Droughts obviously have serious hydrological effects. The main one being lower water levels in rivers, reservoirs, lakes and ponds, which leads on to cause other issues, linked with animals and providing plant roots with water to mention a few. This links with the quality of the water becoming worse, this can include, a change in salt concentrations, increase in water temperature and a change in PH. Even if the volumes of water stayed the same, these impacts would affect the use of the water, as it could become useless, the effected areas could be plants, shrubbery and trees which relied on these water resources to keep them alive.
Forests can suffer hugely in drought, one of the main things, which can affect them, are the increased number and severity of fires. Dead, dried out fallen trees, branches, leaves, grasses and shrub lay on the ground, because they are dried out they are extremely flammable which means that once a fire has begun it is very had to stop or even control, as there is so much flammable material covering the forest floor. Fires not only kill the trees and plant themselves, but the majority of animals, which lived there. Fires can spread in different ways, either across the tops of trees, from the debris on the floor, or when embers fall onto the ground, which then catch alight to other materials. When forests are burnt down it results in the loss of not only habitats and older, fully-grown trees, but also the direst loss of young trees. The ground after a fire is likely to be so dry that it is hard for any plants to survive, or for any new ones to grow and replace those burnt down.
The degration of landscape quality, including increased soil erosion, may lead to more permanent loss of biological productivity of the effected areas. The lack of rain can cause the soil to harden, crack into lumps and eventually crumble into dry dust. Droughts can create wind blown dust bowls, which erodes the landscapes, ruining land and habitats also damaging remaining areas of water and with it, the aquatic wildlife within. Erosion decreases soil productivity due to the loss of plants nutrients, meaning plant roots can no longer hold the soil together, which leads to the degration in soil structure. A good example of this is Lake Naivasha in Kenya, which showed the major effects of drought.
The social impacts of a drought mainly involve public safety, health, conflicts disaster and quality of life. One of the main groups of people affected by drought is the farmer, and as farmers suffer as does community. The severe lack of water kills plants, reducing crop production; issues linked with crop production can also be things such as insect infestations, which spread killing more and more crops, and also plant disease. The lower yields and poor crop quality, not only affects the farmer in the means of lower income, but also all of the people in which relied on the production of the crops to be fed. When there are troubles which producing good crops, farmers may have to look into spending more money on irrigation projects, to stretch out water so that it reaches their land. However many farmers do not have this sort of money, as they rely on their crops alone.
It is not only crops that are affected but livestock also, as the water levels drop, less and less water is available for animals such as cattle and goats and once again, farmers may not have the money to pay for the water to keep them alive, as water costs increase. As a result the farmers suffer from lower income and also the threat of starvation, other methods of getting food, is having it imported from other areas in the country, which are not suffering from drought. This is not only more expensive, but takes more time, and in some cases, is time people don’t have to spare. An issue which links with importing food and water from elsewhere, is that canals and barges may have to take other routes to reach certain areas, because of the low water levels. Livestock owners can also suffer through their animals, as there may be disruptions to the reproductive cycles, due to pressure, bad health or perhaps lack of either male or female animals, all making it more and more difficult to produce more livestock to keep people alive.
Many different businesses are also affected because of drought, one being those that supply for farmers, and work in agricultural production. This can be business, which produce machinery such as tractors, fertilizer producers, food processors and dairy factories. These all suffer due to the severe degration in crop and livestock production. The farmers suffering from low production levels are a direct impact; the impact had on the factories and businesses is an indirect or secondary effect. To follow on from this, not only do the businesses and factories suffer, but also do the workers and their families, as they will become unneeded and wages may drop. Another industry affected is those producing timber, this is because due to the lack of water, the nutrient levels in the soil drops, meaning many plants and trees die as they simply do not receive the water and nutrients from the soil to keep them alive. Therefore they die before they are reached for production, or have simply been able to grow past the young tree stage.
They are also affected by wildfires which spread throughout the forests, due to high temperatures and dry land, this kills the majority of vegetation and trees in the area, and also majorly damages the soil, which means than there will be difficulties for the timber industries to replant and grow new trees for following years. Even if the soil was not damaged bad enough to stop anything growing, when new trees are planted, they will still take many years to reach a height and size which will be of any benefit. This means that those working in the industry will most likely be without a job for a long time.
An additional industry affected is that involved in fishery production. These will majorly be affected, mainly due to the high decrease in water levels, and in some areas the complete destruction and removal of areas of water, such as reservoirs in whole. This can also affect them as fish travel elsewhere where more water is located, this can lead to over population of fish in a smaller area. This links with those businesses, which provide and manufacture equipment for such activities, including hunting and fishing. This could involve the businesses, which make fishing rods or nets, they will be required less, and therefore income will go down. Tourist industries can also be affected, this can include hotels, airports and taxis, as less and less people will be visiting the area at times suffering from drought. High pressure is placed on companies, which supply water.
As the local natural water resources run dry, people rely on other sources. Water prices are increased, and people do not have the money to develop wells, dam’s pipelines and irrigation projects. Power companies, which run hydroelectric industries, will suffer greatly. Companies will have to pay higher prices for energy as more expensive fuels (oil) are used to replace hydroelectric power. Another major issue which people suffering from drought is disease; this is caused by lack of washing, themselves and food, eating bad crops and meat, and also from dead animals.
As mentioned before, fire majorly affects and disrupts timber-manufacturing industries; the rapid spread of bushfires also affects local people. Homes may be burnt down and farmland destroyed, leaving them with nothing. When droughts occur there is also a major pressure placed on jobs, and the lack of need for workers. Those who have jobs working on farms may be dropped as the farmers do not have the money to pay them, or because there is simply so little stock left that it can be handles without the help of others. People working in food manufacturing industries, shops, or any shop for that matter, will be affected mainly due to the lack of product they have to sell, as it is either not being grown or cannot reach them, by not being able to be imported. Banks and people working for them will also be affected, as there is a loss of national economic growth, which slows down the economic development of the effected area. People have less money to spend as their jobs are being cut or they are not able to produce enough to sell.
Drought also affects the health and well being of the people in the affected area. The main issue on wellbeing is the overall health of the people, as they are receiving even less than the small amounts of nutrients they would normally, also due to contamination of food, mainly meat, and sewage disposal. Animals may locate to areas closer to humans as they try to live of and share the same resources, this means that any diseases, which they are carrying, can easily be spread, and passed onto humans. The bad health and death of many people leads to mental and physical stress on many people, most likely those who are responsible for caring for others as well as themselves, this can include anxiety, depression, loss of security and also domestic violence as there is social unrest between many people.
There are also in creased amounts of conflicts between people, both those within a community and between that elsewhere. Water use conflicts are based on people arguing over who is using certain amounts of water, and who should deserve it. Also with water supplying companies, based on their lack of aid. There can also be political and management conflicts. Droughts can cause public dissatisfaction with government regarding bad or lack of drought response, also to the inequality of drought relief, meaning some places may have received help when others haven’t, resulting in some people having to travel far to get it, or simply not receiving anything at all. There is as overall increase in poverty in general, which mainly results in decreasing levels of both Quality of Life and Standard of Living.
An additional result of drought on people is the increase in migration flows. This is usually rural to urban areas in a country, or simply one country to another, which causes refugee problems, an example of this is people travelling into America. Migrations after droughts are often stimulated by a greater availability of food and water elsewhere as most people believe that in the city, because it is richer than the rural areas which they came from everything will be available for them. Migration causes a problem as even when the drought is over, people don’t return home either in case it happens again, or simply because they believe life in an urban area is better. The issue this conjures is that rural areas lack the valuable human resources needed for economic development; as such high amounts have migrated elsewhere. People migrating from a rural to urban area also creates problems for the urban areas as increasing amounts of pressure are placed on it to provide for the ever growing population, this can lead to grater poverty and social unrest levels. An example of such a situation is in Brazil, between the years 1950 – 1980, there was a total loss of 5.5 million people from the northern regions of Brazil, and drought was the reason many of the people migrated elsewhere.
In conclusion it is clear that drought has a major effect on both the environment and people. For those living in an MEDC, I believe that drought would still be a major issue, however they would be able to overcome it much easier than those living in LEDC’s. Additionally MEDC’s invest in LEDC’s, which means that it is not directly their country, which is affected. However for the people living in an LEDC, they rely mostly on their surroundings, growing their own crops, rearing livestock to feed people and generate an income for themselves. I believe that the environment and people are both effected in different ways, due to drought; some effects are more severe than others, although one main point is that people rely on the environment to survive.