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LAND (SOIL) DEGRADATION;
Land (soil) degradation refers to the deterioration of the quality of land (soil) through the loss of fertility, soil pollution, erosion and mass wasting. Degradation rendered soil useless for human developmental activities and unfit for the life of soil biota.
Loss of soil fertility;
This refers to the decline in the soil ability to support plant growth through the failure to provide necessary nutrients for plant growth. Loss of fertility can brought about in a number of ways as explained below:
1) Leaching process: This washes down the necessary nutrients in solution from the topsoil. It makes soil become more acidic and hence toxic. It is common in areas, which are humid and experience heavy rains.
2) Over cultivation: In certain areas caused by the rapid population growth. The crops grown on the same piece of land for a long time lead to depletion of soil nutrients.
3) Monoculture that involved cultivation of one type of crop without crop rotation or inter cropping. Nutrients are used up without replacement and the soil structure can be destroyed rendering the soil unstable.
4) Soil pollution due to excessive use of chemical like pesticides and artificial fertilizers, dumping of harmful wastes in the soil, and acidic rain that make the soil toxic, structure less and hence unproductive.
5) Soil erosion accelerated by poor land management like deforestation, flat cultivation on the slopes, etc.
6) Mass wasting that leads to the loss of the upper layer of soil and its nutrients.
7) Severe loss of soil water through excessive vapor- transpiration especially in arid and semi arid areas.
SOIL EROSION
Soil erosion refers to the wearing away, detachment and removal of soil material from one place to another through the agents like water, wind, ice and gravity.
Types of soil erosion:
Two major types of soil erosion can be distinguished and these include normal geological erosion and accelerated erosion. Is the wide spread type of erosion that occurs wherever there is natural flow of energy and matter on the earth’s surface without human (anthropogenic) influence. It is fortunately very slow and so not normally injurious to the soil cover of the world. More often than not, its rate is either slower or equal to the rate of soil formation hence its effects are rarely noticeable. Erosion under this category is easy to control.
Accelerated erosion;
Accelerated erosion;
Is the type of erosion associated with man’s activities (man induced or anthropogenic). It is spectacular in nature (very destructive), therefore it has attracted man’s attention. Its side effects include physical loss of soil nutrients, leading to severe economic loss arising from the reduced crop yield or total crop failure, and / or wasted efforts and money spent on unsuccessful soil conservation projects.
Factors Affecting or Controlling Accelerated Erosion;
These factors can accelerate or decelerate the rate of erosion; they induced physical and human factors.
Physical factors range from climate, topography, nature of soil and vegetation cover;
1) Climate: Where there is heavy rainfall erosion takes place easily while where there is little rainfall the rate of erosion is also low.
2) Topography: On steep slopes soil erosion tends to be severe while it is slow on gentle slopes.
3) Nature of soil: Erosion tends to be severe where soil is loose and tends to be slow where soil is stable.
4) Vegetation cover: Where there is dense vegetation soil erosion tends to be slow while where the soil is bare and the ground is sloppy soil erosion tends to be sever.
Human factors include management styles and population change.
- Good soil management like crop rotation and a forestation helps in reducing or checking soil erosion but where there is poor soil management erosion takes place easily.
- Population increase also leads to over exploitation of resources especially minerals, forest and land through over cultivation. All these lead to soil erosion.
- Human activities that cause accelerated erosion include poor cultivation like monoculture and flat cultivation, excessive mining construction activities which involved building of houses, construction of roads etc; excessive cutting down of tees for lumbering and fuel; overgrazing and casual burning.
Effects of Soil Erosion
Soil erosion has various effects which include water pollution, loss of soil fertility, migration of people, reduction size of arable and deforestation, destruction of animals habitat accelerating weathering process by exposing the rocks disrupting transport and communication network, destruction of tourists centers and houses, and making man incur costs of repair after destruction has been exacerbated by self erosion.
SOIL MANAGEMENT AND CONSERVATION MEASURES;
Soil management renders to the skillful use or wise utilization and control of quality of soil (land) resource. Soil conserva
tion refers to the process of preserving the soil for proper and sustainable use. Management and conservation of soil involve the following activities, which are carried by human being.
tion refers to the process of preserving the soil for proper and sustainable use. Management and conservation of soil involve the following activities, which are carried by human being.
1) Educating people so as to promote land management skills among them. This has to be undertaken by the government in collaboration with NGOs and some individuals.
2) Training and encouraging farmers to use proper farming methods like crop rotation, inter-cropping, and the use of organic manure. Other methods that can be encouraged include strip cropping and contour ploughing.
3) Planting of cover crops, a forestation and reforestation in order to check soil erosion.
4) Reducing or stopping the use of industry chemicals which tend to accumulate in the soil and cause deleterious pollution.
5) Waste products should be recycled rather than dumping in the soil.
6) Animals should be destocked in order to avoid overgrazing that leads to destruction of grass.
7) Encouraging dry farming that involved mulching in order to reduce loss of water through evaporation especially in dry areas.
8) Land lining with brushwood should be used where the oil has been severely eroded producing gullies.
9) Population should be controlled so as to discourage excessive exploitation of resources, which in turn leads to land degradation.
10) Alternative energy resources should be explored and used effectively to avoid the excessive use of forest materials and oil, which causes hazards to the environment.
11) Radioactive materials should be dumped very deeply in the soil to prevent the upper soil layer from being highly affected.
12) Terracing, and construction of stone lines (like in Burkina Faso) and check dams (like in China) should be undertaken so as to control the movement of water and force it to get into the soil rather than flowing over the land.
13) Developing other economic activities rather than depending on agriculture only especially in the developing countries.
14) The government should formulate good policies, which advocate community participation, land tenure and encourage the proper use of land. Where possible people should be given financial support so as to invest unscientific agricultural techniques, which are not precarious to the soil.
Environmental Hazards and Catastrophes, some key terms;
1) Hazards are the event that occurs and when taking place they put the life of living organisms in danger or at risk.
2) Antistrophe refers to a disaster or calamity that entails destruction of properties as well as environmental degradation.
-Catastrophes are caused by hazards and they are assessed in terms of damage or loss which occurs when the destructive events strike at a place.
-Catastrophes are caused by hazards and they are assessed in terms of damage or loss which occurs when the destructive events strike at a place.
-Hazardous events include acid rain, drought, floods (e.g. caused by El Nino rains), famine, storms, earthquakes, volcanic eruptions, epidemics, pests, and mass wasting.
Acid Rain;
All natural rain (precipitation) is usually somewhat acidic as a result of solution of gases like carbon dioxide that react with water to form acids. Carbon dioxide forms carbonic acid (H2CO3). Clean rainwater has the PH value between 5.5 to 6) PH 7 is neutral. Highly acidic water has the PH value lower than 5. It can be 2.4 -5. But recent research in some places have shown that some rainwater contain more than average amounts of acids. This was first discovered in Scandinavia in the 1950s. Acid rain, therefore, is the rain containing more acids than normal amount.
Formation of acids rain;
- It is formed in the air from sulphur dioxide and nitrogen oxide which are emitted by thermal power stations, industry, motor vehicles, strip mining of coal and burning of coal, sea spraying suing chemicals containing sulphate minerals.
- Developed (industrialized countries) are the major contributors in this problem. These are the USA, Britain, Japan, etc.The countries greatly affected by acid rain include Scandinavia, the UK, Eastern Canada, and Germany in the black forest.
Effects of acid rain;
1) It leads to the increase in acidity in water bodies killing aquatic animals and plants. This is water pollution.
2) It also leads to the increase of acidity in soils reducing the number of plants that can be grown. Some plants die leading to poor agricultural production.
3) It is washed away through the leaching process accelerated by the presence of acids in the soil. In Germany and Eastern Canada forests died because of this phenomenon. The trees die because they become less resistant to drought, frost and diseases. Also their cells are destroyed.
4) As water supplies become acidic they pose a threat to the future health condition. For example the release of extra aluminum has been linked to Alzheimer’s disease.
5) Different structures like buildings, monuments and bridges are destroyed as a result of the corrosive action of acid on paints and rocks containing calcium.
6) Erosion of limestone rock leads to the formation of features like sinkholes, do lines and gripes.
6) Erosion of limestone rock leads to the formation of features like sinkholes, do lines and gripes.
7) Sulphuric acid lead to itching and irritation of eyes in human being and animals.
Measures towards combating the problem of acid rain;
1) Spraying the trees to wash off acids and auditing of line to the soils, lakes and rivers to reduce acidity. These have been done in Germany and Scandinavia. But these processes are expensive and not sustainable since they have to be repeated continually.
2) Reducing the emissions of sulphur dioxide and nitrogen oxide by using non-fossil fuel, coal which contains less sulphur, removing sulphur from coal before being used. This is desulphurization and can be done by either washing finely ground coal or treating sulphur with chemicals.
3) Introducing the new boilers in power stations which can burn sulphur dioxide into ash. This can be done by burning coal and limestone together so that sulphur can stick to limestone when burning. This process is referred to as fluidized bed technology.
4) Trapping sulphur dioxide from waste gases and spraying it with water so that it can form sulphuric acid which can later be neutralized by adding lime. This process of removing sulphur dioxide from waste gases after use is referred to as Fuel Gas Desulphurization.
5) Using alternative sources of energy, which do not pollute the air. The country can turn the coal-fired power stations into gas-fired power station or becoming more reliant on nuclear power. Also geothermal power, solar power, water power as well as wind power can be used since these are environmentally sustainable.
6)Using less energy by turning off the lights when not is use since the cables tend to produce nitrogen oxide when the electric current is passing.
7)Use car pools, public transportation or resort to walking so as to reduce the burning of fuel oil that leads to the production of nitrogen oxide.
8) Recycle the wastes to avoid unnecessary decomposition that leads to the production of sulphur gas.
9) Reduce air conditioning and the use of heat since these produce nitrogen oxide.
10) Replacing the old appliances and electronic gadgets with the newer energy efficient products.
11) Adding scrubbers to utility plants so as to reduce the emission of Nitrogen gas.
12) Strict policies should be formulated to restrict the use of energy that leads to emission of sulphur dioxide or to control human activities so that the rate of production of sulphur dioxide and nitrogen oxide can be reduced.
DROUGHT
Drought is a state on an area facing prolonged conditions of dry weather without precipitation or long period of dry weather when there is not enough water. Drought and desertification have something in common in terms of occurrence and effects.
Causes of drought
Natural causes
These entail natural aspects like the wind system dynamics, the shifting of the overhead sun, natural location of some places, Natural fires and earthquakes.
Winds
Wind systems that are dry since they have blown across very narrow water mass stretch cause drought, as they have not picked enough moisture to cause rain formation. The Hartman winds of West Africa are such types of winds which have contributed to the occurrence of drought conditions in many West African countries, particularly the Sahara region.
Some of the winds are dry because they have passed across the cold ocean currents over which they have dropped a lot of moisture and hence reach the surface when they are already dry causing dryness. Dryness in the western part of Southern African countries especially in Kalahari is due to cold dry winds that cross the Benguela ocean currents. In areas where there are descending winds, there is no rain formation since the descending air masses are stable and do not causes rain formation. Rain formation happens where air masses rise, cool leading to condensation and later rain formation.
Shifting of the position of the overhead sun
It is the shifting of the overhead sun takes place, the rainfall regime shifts. If it shifts to the Northern Hemisphere, there occurs dryness in the Southern Hemisphere and when it is in the southern hemisphere dryness occurs in northern hemisphere.
Loca
tion of places
tion of places
Some places are located in the leeward side of the mountains and therefore experience dryness due to the rain-shadow effect. Other places are located very far in the interior such that they end up receiving low amount moisture or no moisture at all.
Natural fires
These are the fire caused by the natural hazards like lightning and volcanic eruptions. These can lead to a large scale destruction of vegetation leaving the land bare. The bare land can then experience excessive evaporation that leads to loss of moisture and hence the occurrence of drought.
Man induced causes
These entails activities carried out by man such as:
1) Lumbering that leads to deforestation due to excessive cutting of trees.
2) Bad agricultural practices like overgrazing, over cultivation, and shifting cultivation.
3) Establishment of new settlement areas due to the increase in population leads to cutting of trees.
4) Mining activities and construction of dams can also cause deforestation.
5) Industrial activities and cars have an impact on the occurrence of drought. These emit gases that cause global warming and acid rain. These causes death of vegetation leaving the land bare and later the occurrence of drought.
6) Other factors involve poor or lack of population policies, low level of technology and poverty. These have led to poor environmental management that has resulted in the destruction of vegetation and thus the occurrence of drought.
Impacts of drought;
1) It has led to poor supply of water for domestic use, agricultural use and industrial activities.
2) Drought has caused the disappearance of vegetation in many places especially in the Sahel region in Africa.
3) Poor energy supply among the people who depend on firewood as the main source of energy. This has faced people in West Africa.
4) Lack of moisture in the soil has led to death of plants. The land left bare due to the death of vegetation is susceptible to erosion.
5) Excessive evaporation
has led to the drying of water bodies especially the seasonal lakes and streams in Central and West Africa.
has led to the drying of water bodies especially the seasonal lakes and streams in Central and West Africa.
6) Drought condition has facilitated the desertification process in different parts leading to the reduction of the size of the arable land.
7) Agricultural activities decline due to the death of crops leading to the problems of food availability (famine / starvation).
8) Drought conditions force people to migrate from the affected areas to other areas, which are not affected, and this can cause problems of population pressure, land fragmentation and land conflicts.
9) Industries that depend on agriculture can decline like the textile and food processing industries.
10) Women and children suffer a lot in the following ways:
a. They are forced to go long distance search of water and hence they get tired, deteriorate in terms of health, and face accidents like being bitten by snakes, being raped or being killed.
b. Women and children also don’t get time to attend learning institutions since they spend most of the time looking for water and firewood. Performance of girls in school can decline due to lack concentration in school.
c. There can be problems of acceleration of immoral practices since when children and young girls go so much far they can free that they are free of parents attention and decide indulging in misbehavior. Some young girls and boys can use the chance to meet so much far where they are searching for water or firewood and indulge into immoral behavior. This can lead to the spread of HIV/AIDS and unplanned pregnancies among the young girls.
d. Women cannot engage in other activities effectively because of being tired.
11) In some places men are forced to go very far looking for firewood where women cannot reach.
Measures to combat the problem of drought
1) Embarking on a forestation and reforestation programs. The trees add moisture to the atmosphere and hence lead to rainfall formation.
2) The use of proper farming methods which do not deplete vegetation.
3) Control of population should be encouraged so as to avoid the excessive depletion of vegetation.
4) The water conservation centers should be established like dams so as to promote irrigation schemes.
5) Farmers should be given proper education on how to use the resources sustainably to avoid environmental degradation.
6) Strict policies should be instituted so as to restrict the excessive use of trees.
7) There should be introduced the use of alternative energy sources like solar energy, wind energy, geothermal power, water power etc, that are environmentally sustainable.
FLOOD
Flood refers to a period of either high river discharge (when a river overflows its banks because of excess water) or overflow of water along the coast due to extremely high tide and storm waves.
Floods occur as a result of heavy rains that take place in a particular place and they affect so much the lowland areas especially where vegetation has been cleared.
Other floods can occur due to the collapse of reservoirs like dams, emergence of springs, melting of ice and breaking of the water pipes. Also tides caused by the gravitational forces between the earth and the sun or between the earth and the moon as well as the strong waves due to the influence of stormy winds and the earthquakes can lead to floods. This occurs most frequently in the humid regions like equatorial areas due to heavy rains. Nut even in the desert areas, occasional torrential rains can cause flooding.
Factors that can accelerate flooding in lowland areas;
1) Shallowness of the soil due to the presence of the impermeable rock layer just near the surface.
2) The presence of the water table near the surface as a result of soil saturation. When rain water falls on the surface that already is saturated. When rain water falls on the surface that already is saturated with water, floods occur in the river stream since it does not soil down instead it goes to the river channels leading to overflow.
3) Clearing of vegetation accelerates flowing because on a bare surface water runs freely to the streams and end up filling them.
4) Shallowness and narrowness of the river stream can also lead to the occurrence of floods in a certain place.
5) Floods also can take place where the rivers have so many bends, or are blocked by vegetation or the floors are almost flat such that the water entering the channels does not flow settle down stream leading to overflow of water on either side of the river channel beyond the river banks.
6) Damming of the river by human being or by layer spewed out during volcanic eruptions can cause flowing of water on the upstream side.
7) Blocked up drainage systems in the towns or cities can also trigger of the problem of floods.
8) Earthquakes that take place below the sea tends to lead to the formation of large waves called Tsunamis which send water to the coastal areas and cause catastrophic waves.
Floods have been taking place in many parts of the world like Bangladesh, China, Mozambique, Malawi etc. the floods that took in Tanzania in 1998 were so severe that they led to great damage in many parts of the country. Also on Sunday 26th December 2004 there occurred. It was reported that on that day the tsunamis killed about 100,000 people in about 12 countries. The Tsunamis took about eight hours from Sumatra which was the epicenter to reach the East Africa coast. Ten people died in Dar es Salaam after the Tsunamis.
Impacts of floods;
1) Death of people and animals. For example the frequent floods in Bangladesh have claimed the lives of many people leading to depopulation. The death of animals also affects livestock husbandry in a negative way.
2) Farmlands can be destroyed by the running of water leading to devastation of crops. Devastation of crops leads to poor food supply and hence the prevalence of famine.
3) Outbreak and spread of water-borne diseases occur affecting the health of people and sometimes death. This is due to water pollution.
4) Floods make the governments incur costs in terms of required the victims. They have to help them in terms to medication, food the shelter.
5) Floods also lead to the demolition of houses rendering people homeless.
6) Silting of the dams and other water reservation resulting problems of water conservation and inadequate water supply.
7) Floods can lead to soil and air pollution. During floods the chemical from the dumping places can be taken away and spread other areas leading to soil contamination. Also decomposition of material under water condition such as peat, can lead to the emission of greenhouse gases like methane.
8) Floods lead to the occurrence of soil erosion and the occurrence of landslides.
9) Destruction of infrastructures like railways, roads and bridge. The electricity posts can be dislodged leading to fire out break and blackout in the towns.
10) Floods bring problems of industrial location in a particular place.
11) As a result of disruption of transport system, the movement of goods and services is hampered resulting in the rise of prices of goods and shortage of important services.
12) It leads to migration of people who move as refugees to other places or countries.
13) Destruction of economic sectors like farms and industrial structures leads to the occurrence of poverty in a country.
14) It also affects people psychologically since they feel unsafe and uncomfortable to live like refuses in another place.
15) But in some places especially in the flood plains, they have lead to the development of fertile soil through alluvial deposition. These are used for agriculture.
Response to the occurrence of floods;
1) There should be proper management of the watershed or catchment areas through planting trees. Vegetation checks water movement on the surface and forces into to soak into the ground. Hence people should not be allowed to settle in the catchment areas.
2) Construction of dams across the river channels helps in combating the problem of floods which affects the lowland areas.
3) The stream of the rivers should be deepened, widened and straightened so as to increase the speed of the river down the slope to the sea or lake. This process is called channelization.
4) People should avoid living in areas, which are prone to the occurrence of floods like the lowland areas, especially, the flood plai
ns like those in the Msimbazi river valley and coastal areas which usually experience Tsunamis, such as the coast lands of Chile and Peru due to earthquakes. Tsunamis are the waves in the ocean caused by the shocks produced by earthquakes that start from below the ocean floor.
ns like those in the Msimbazi river valley and coastal areas which usually experience Tsunamis, such as the coast lands of Chile and Peru due to earthquakes. Tsunamis are the waves in the ocean caused by the shocks produced by earthquakes that start from below the ocean floor.
5) People who live in the lowland areas should create efficient drainage systems that can take water away from their residential areas.
6) There should be frequent inspection and cleaning of the drainage systems in the town to avoid the problem of blocking.
7) There should be established efficient rescue teams, which can help people during floods. The team should be well equipped with rescue facilities.
8) During floods, people should respond fast to go and help the victims and help them in terms of medication, food, clothes etc.
9) International cooperation should be intensified so as to improve the techniques of combating this environmental predicament.
FAMINE
Famine refers to a situation in which there is shortage or inadequate food supply in the country. The severe scarcity of food is referred to as starvation. Famine has becomes a great problem in many parts of the African continent especially in the sub- Sahara countries.
While the developed countries have been witnessing steady increase in food production and supply since the 1960s, the Africa continent has been experiencing an exceptional decrease in food production leading to the rise in number of under bred people. While food production has been declining the number of people has been increasing leading to inadequacy in food supply and hence poor diet, either in amount (quantity) or type (quality), Between 1970 and 1990 there was an increase in availability of food supplies per capital in every developing region except sub-Sahara Africa. It has been estimated that in most developing countries, especially those within the tropics, a person consuming less than 2350 calories per day is likely to experience chronic malnutrition. In 1990, 20 percent of people living in these countries were suffering from chronic malnutrition. Their numbers have increased from 435 million in 1975 to 600 million in 1990 (David Waugh 1998).
Factors leading to the occurrence of famine in the sub-Saharan Africa;
1) Rapid population growth as a result of high birth rate and falling death rate. This has led to the increase in number of people to be fed and most of them are young children who are yet to be fully engaged in the production process. The rapid increase in population has also led to the problem of pressure for land, causing land fragmentation and hence hinders application of machinery in farms.
2) Poverty is another problem. Few farmers have financial ability to buy high yielding seeds, fertilizer, pesticides or machinery, or to implement irrigation schemes. Also when food is scarce, neither the government nor people can afford to buy high priced food surplus from the developed countries.
3) There is too much emphasis on the production of cash cross since the colonial times. This has made farmers neglect food crops leading to scarcity of food.
4) Political instability in many countries has been another contributing factor. There are incidents of civil wars in many countries like The Democratic republic of Congo, Liberia, Rwanda, Burundi, Nigeria, Cote D’Ivoire etc leading to insecurity and lack of peace. During these wars, many people are restless; some are force to migrate as refugees to other neighboring countries. Tanzania for example has been receiving to many refugees from Burundi and Rwanda as result of strife in those countries. Hence, people cannot concentrate on production leading to problem of food availability.
5) Rural – urban migration has been another factor. The movement of young and energetic people from rural areas to the urban centers has led to shortage of labor in rural areas where agricultural production takes place. Those who remain in the rural areas are the old people, women and children who cannot engage themselves effectively in the production process.
6) Low level of technology among many African farmers is also another problem. People are still using traditional ways of cultivation, using hand hoes is so common in many countries especially in Tanzania, Malawi, Kenya and other countries in this region. Low technology has been attributed to the problem of illiteracy and poverty.
7) Too much selectivity on the type of crops to produce for food has also been affecting food production. There are some communities that need only certain types of crop for food and they are not ready to switch to the other types of crop. For example some prefer maize as their staple food. During drought maize production tends to be poor. Once such people are told to grow cassava might end up refusing since they are not used to that crop as source of food. This leads to food shortage among such societies when it comes to problem of drought.
8) Land conflicts are other hindrances in Africa. There have been incidents of conflicts in Zimbabwe, even in Tanzania in Kilisa, Arusha and Mara region. These conflicts for land hinder production process as people waste a lot of time in such quarrels.
9) Casual bush fires also lead to the destruction of crops in the farms. Fires are so frequent in many Tropical countries during the dry seasons when peopl
e are about to harvest. The fires devastate crops and pose problems of food supply.
e are about to harvest. The fires devastate crops and pose problems of food supply.
10)Lack of or poor agricultural policies in many countries in the sub-Saharan region are a great snag. There are not clear agricultural policies that govern the production process. There are not well stipulated land tenure policies in many countries which are one of the causes of land conflicts. Hence, people produce without having proper guidance on what to produce and how to produce.
11)Poor transport and communication has also affected production and availability of food. There are places, which tend to produce food in great amount while other places experience crop failure in the farms. But problems of transport pose difficulties in ferrying food to other areas which are experiencing food shortage. For example in Tanzania, Rukwa region produces food in great quantities but that food is usually not easily sent to places like Dodoma, Singida and Shinyanga because transport encumbrance.
12)Soil erosion has a great contribution to agricultural failure. Erosion has been so severe in many places of the sub-Sahara region, in some places, like the Sahel region soil erosion has led to desertification. This causes failure in agricultural production. Soil erosion in Tanzania has been experienced in many places like Kondoa district in Dodoma and many parts of Mbeya and Iringa.
13)Poor storage facilities in rural areas have been another problem. Some crops are destroyed in the farms or in poor storage places leading to food scarcity.
14)Negative attitude to agricultural activities and laziness. Some people are despising agriculture as the activity of the poor people and hence they offer other jobs like trade, mining, etc. others are lazy by nature. These contribute to the occurrence of starvation.
15)Smuggling of food to other countries is another problem. Farmers after harvesting they tend to sell virtually all the food through smuggling to other countries where there can be higher prices. For example in Tanzania, there has a big problem of smuggling the food to Kenya, Zambia etc.
16)Misuse of the available cereals. The available cereals are usually misused. For example maize, sorghum and millet are usually used in making local brew in rural areas. Such practices have affected food availability in many countries.
17)Pests and diseases have had a great contribution in the prevalence of famine. Pests and diseases destroy crops and animals. There are birds like quelea, other pests like graining borers, stalking borers and fungal diseases that attack crops. Other diseases like Nagana, Foot and Mouth Disease, East Coast fever kill animals. Human beings also are affected by diseases like AIDS, Malaria, Cholera, and Meningitis which affect their health and sometimes or in most cases claim their life leading to a problem of labour supply.
18)Unreliable rainfall or small amount of rainfall leads to poor agricultural production. This is a big problem in many tropical countries and especially in the central parts of many countries. In Tanzania rainfall is so scanty in Dodoma, Shinyanga, some parts of Tabora and Singida. Those places experience low crop production.
19)Decline in fertility as a result of leaching and over cultivation has been so marked in many countries. Due to over cultivation and leaching, few nutrients have remained din the soil leading to decline in production.
20)Poor marketing system is also a hindrance. The cash crops are sold at poor prices and payments are made so late. This makes most farmers in rural areas fail to buy food since they usually have no money. They also fail to invest in advanced agriculture so as to promote production and diversification of the economy.
21)Lack or poor agricultural researches made and once they are made the results are not utilized effectively to improve agriculture.
22)Competition posed by other activities against agriculture. Mining sectors and industries have been absorbing more labor from rural areas leading to labor shortage in the farms.
23)Lack of cooperation between men and women in the agricultural process. Traditionally, women and children have been the major labor suppliers in the farmers while men are indulging in drinking etc. think has contributed to inefficiency in food production in many countries.
24)Late sowing or planting can cause failure in agriculture. Some farmers plane or sow the seeds when it is too late for the crops to grow into maturity.
25)Natural hazards like floods caused by too much rainfall especially during El-Nino rains.
26)Floods destroy crops in the farmer.
What should be done?
In order to combat the problem of famine, the following measures should be taken:
1) Most countries in the sub-Saharan region should adopt population control policies so strictly so as to have number of people that can be well sustained by the current food supply level.
2) There should be improvement technology through researches, education and training of the farmers in rural areas.
3) Farmers in rural areas should be encouraged to adopt sedentary agriculture rather than keep on shifting from place to place since it is time waste.
4) There should be strict and well – stipulated policies on agriculture and land tenure so as to encourage people to produce food crops and solve and conflicts.
5) The control of pests and diseases should be encouraged. There should be the use of pesticides to kill pests. The medical services should be improved to combat diseases like malaria.
6) Transport and communication of crops to different parts of the sub-Saharan Africa.
7) Reconciliation of conflicting countries like Burundi, Liberia and The DCR so that peace can be attained and maintained. When peace is maintained people will have confidence to engage themselves in the agricultural production process.
8) Restricting rural-urban migration is another response. There should be development planning focusing on rural areas. The farmers should be given loans and social services be given to rural areas like electricity, education, health services, and water in order that people can stay in rural areas rather than going to urban center’s.
9) The local markets in the respective countries should be improved to discourage food smuggling to other countries or regions.
10)Construction of good storage facilities in rural areas can help to combat the problem of food destruction.
11)The private sector should be encouraged to get involved in agricultural production instead of concentrating on industrial production.
12)Women empowerment can be another solution in solving the problem of food availability. When women are empowered they can also help in making decision that pertains to agricultural production. Men should also cooperate in the agricultural production process so as to promote efficiency.
13)The farmers should be educated on how to conserve the soil in order to attain sustainable agricultural production.
14)Diversification of crops should be encouraged. People should not depend on only one crop since once that crop fails they can experience problems of food shortage so severely.
15)Introduction of irrigation schemes in arid and semi-arid areas can help to increase food supply in these countries. Together with these schemes, there should be construction of dams that can be used in supplying water to the irrigation areas.
16)Occurrence of heavy rains, severe storms and floods in the eastern part of the Pacific – South America, Chile, Peru, South of California and even in Africa.
17)Heavy rains and floods lead to erosion water pollution and problems of transport.
18)There occurs destruction of crops by heavy rains and flood leading to famine. Also heavy rains and floods demolish houses rendering people homeless.
19)The land degradation and too much water lead to migration of people and animals and sometimes lead to death when the houses collapse or due to drowning in water during floods.
20)Industries and trade decline since goods are not transported from one place to another during floods. Also, the supply of industrial raw materials can be disrupted as of result of the destruction of cash crops in the farms.
21)Leads to costs of repairing the destroyed structures like bridges roads etc.
22)Erosion leads to the reduction in the size of the arable land.
23)Drought conditions occur in places like South East Asia and Australia. This can lead to deforestation as a result of the death of plants, crop failure, air pollution by stormy winds, migration, famine and death of animals due to lack of food and water supply. Likewise, sunny conditions are experience in Oregon, Washington and Britain. The usual rains in these areas stop during the El Nino period.
24)Severe fires that ravage or raze the forest vegetation are common in Indonesia and Australia due to severe drought conditions.
25)High waves occur in California as a result of the dragging effect exerted by the reversed Trade Winds that are associated with the drop in pressure in the eastern Pacific Ocean. These waves affect the coastal areas in terms of erosion and floods.
26)The fishing industry especially in Peru and Chile declines following the death of some fish caused by the lack of nutrient supply. The supply of nutrients stops in these areas because of the absence of water upwelling that is common during La Nina. The upwelling of the cold water in the eastern Pacific Ocean takes place since it tends to replace the water on the surface that has been dragged westwards by the normal Winds. As such they bring nutrients from the bottom to the surfaced water making them available to the fish. But such a supply stops during El Nino since there is no water upwelling.
Loss of Biodiversity
1) Biodiversity – refers a variety of species of living organisms both plants and animals (Flora and Fauna)
2) Loss of Biodiversity – refers to the disappearance of different plant and animal species in a particular geographical unit or community (ecosystem)
3) Ecosystem – is a natural system in which plants (Flora and animals (Faun) interact with each other and the non-living environment.
Environmental problem have affected adversely different species of plants and animals such that there is a high rate of loss of various plant and animal species; especially those, which are valuable to man. The valuable species are among endangered species in the world now since they are highly depleted through injudicious human use in meeting different needs of life. Among endangered species are plants, which are used for lumbering like Mninga in Miombo woodlands of Tanzania and animals like the rhinoceros, elephants, etc which are hunted for their tusks and ivory. In this topic on the Loss of Biodiversity, the focus will be on the depletion of forest resources and different animals’ species in the wildlife conservation areas.
FOREST RESOURCES AND THEIR PLIGHT
Forests refer to the thick growth or collection of trees covering a large area. The forest can be natural or anthropogenic (means created by man). The science of planning trees and managing or improving the forest is referred to as Forestry. The process in which an individual or individuals purposefully plant tree and takes care of them until the harvest time, and then after harvesting replant tree under proper management is referred to as silviculture. This is part of forestry only that it deals with man made forest.
Importance of forest;
1) The forest helps in soil conservation since the trees form a protective cover that prevents soil erosion. It prevents erosion from taking place by checking the speed of the flowing water on the ground.
2) It also provide habitat for the animals and birds of different species.
3) The forest helps in the modification of the climate leading to the formation of rainfall. It introduces water vapor into the atmosphere through transpiration, which on condensing forms rainfall.
4) Forests clean the air by absorbing canon dioxide which is used for photosynthesis, the process which in turn introduces oxygen into the atmosphere as the end product. Hence forests are one of the carbon dioxide sinks in the world.
5) Trees are a source of energy since they are used for firewood and charcoal making.
6) From the forest there can be extracted the building materials like poles and timber.
7) The forest is also important in the paper and pulp industry from which writing materials are produced.
8) Some tree species are used for making medicine and some provide fruits. Hence they are the source of food. Also, from the flowers there can be obtained some ornamental flowers.
9) The forest is important in the soil profile development since when the trees dies, they decompose and form humus, which gets mixed with the rock fragments to form soil.
10)The liquid from the trees is used for making gum, dyestuffs and other different types of chemicals.
11)Forests maintain water bodies like river; sources of water like catchment areas, lakes and springs. They also maintain moisture in the soil by reducing the impact of excessive evaporation.
12)The forests also encourage the development of tourism since when there are many tree species they promote the scenic view, which can be very attractive to the tourists.
13)Forests are the centers for recreation. Some picnics tend to take place in the forest.
14)They are also centers for scientific researchers by different researchers from different institutions that are having studies related to botany.
15)They also act as wind barriers so as to reduce destructive impact of wind to the residential areas or in the farms like cocoa farms in Ghana.
16)Forests are a source of employment especially in the forestry centers.
17)Forests are important for flood prevention since they force water to soak into the ground rather than running into the streams.
18)They also help in stabilizing the soil and prevent the occurrence of mass wasting especially the landslides on the slopes of the mountains.
19)Forest products are used for making different things for home use like furniture, utensil, etc.
Deforestation
Deforestation refers to the destruction of the forest through depletion or disappearance of different tree species. This can be by natural processes or by man’s influence. Deforestation is a great problem in different parts of the world.
Agents responsible for the disappearance of the forests
These can be grouped into natural factors and human factors.
Natural factors
Natural factors include natural disasters like volcanic eruptions, hurricanes, aridity and lightning.
- Volcanic eruptions usually lead to the occurrence of fire in the forests that ends up destroying the trees. Also, lava spewed out can bury vegetation over a large area, Strong stormy winds like hurricanes up roof trees leading to deforestation.
- Aridity that leads to the drying of soil causes the death of trees and hence deforestation.
- The lightning can cause fire in the forest that can ravage the trees and cause the disappearance of many tree species.
Human influence
Human being has been blamed of being a major culprit in the current times in causing deforestation at an alarming rate. The influence of human being is both drastic (rapid) and dramatic (striking). The role played by human being in the forest depleting has been through various ways as follows:
1) Poorly organized agricultural activities like shifting cultivation, which has cost Africa in terms of felling trees and bush burning when clearing the areas for cultivation. Also plantations that involve clearing of large areas lead to disappearance of vegetation. Poorly organized pastoral farming characterized by overgrazing and browsing as a result of overstocking leads to the depletion of vegetation.
2) Fires that are lit by man when encouraging the growth of fresh grass, hinting as well as extraction of honey has contributed to the wiping out of different species of trees.
3) Lumbering activities involve cutting of the trees. Man has been cutting
these trees indiscriminately leading to devastation of forests species.
these trees indiscriminately leading to devastation of forests species.
4) Lumbering activities involve cutting of the trees. Man has been cutting these trees indiscriminately leading to devastation of forests species.
5) Construction of roads, railways, dams and establishment of settlement (like urban development) have degraded the forest to an appalling extent.
6) Industrial activities have had a great contribution in the deforestation process. The industrial emissions have led to formation of acid rain in countries like Germany, Scandinavia and Eastern part of Canada leading to the soil pollution and hence death of various plant species. Also the establishment of industries involves cutting of trees, which leaves the land bare.
7) The search for wood and charcoal as sources of energy has also led to removal of trees beyond which re-growth and easy planting can permit. Because of poverty people resort to cheap energy sources like firewood and charcoal therefore encouraging or accelerating the depletion of trees.
8) Rapid population growth that causes pressure or stress on land resources has been another problem. As a result of the increase of people new areas are needed for cultivation and settlement. These involve cutting of trees and hence deforestation.
9) Formulation of relaxed policies on forest conservation in the country can lead to the devastation of trees. When there is no strict policy governing on how to use resources, it becomes very difficult for the people to carry out their activities in a sustainable way.
Effects (consequences) of deforestation;
1) Deforestation leaves the land bare and hence land degradation (soil erosion) can take place easily.
2) Reduction of the size of the land caused by erosion accelerated by deforestation.
3) Deforestation leads to the destruction of habitation of animals and birds.
4) Valuable species used for timber like Mninga, Mvule, mahogany and Sapele disappear as a result of deforestation.
5) Desertification occurs as a result of tree cutting. This gives room for the encroachment of aridity in different areas even those, which were once forests.
6) Drying up of the water bodies like wells, rivers and ponds as well as the catchment areas due to excessive evaporation. Excessive evaporation takes place because of the bare land exposed after the disappearance of trees.
7) Tourism declines due to
energy crises, loss of various species of trees and animals, drying of water bodies, occurrence of catastrophic storms and pollution.
energy crises, loss of various species of trees and animals, drying of water bodies, occurrence of catastrophic storms and pollution.
8) Women and child girls get problems of walking very far in search of firewood and water. This leads to problems like being raped or being attacked by dangerous animals.
Initiatives towards forest conservation
The following are the advisable options that should be adopted by the government, NGOs and people.
1) There should be introduction or adoption of reforestation and reforestation programs. Forestation refers to planting of trees where there were notes existing before. Reforestation refers to planting trees where there were but were cut for various purposes.
2) Declaring some of the areas as protected by law so as to prevent people from cutting trees at random for lumbering, construction or when clearing the areas for cultivation and establishing settlement. In Tanzania, for example, there are areas declared as “Forests reserves” if “Protected areas”
3) People should be given education and training on how to conserve the forests and the important of that. They should be made to participate in decision making process pertaining to forest conservation as well as other agenda.
4) There should be formulated well – stipulated and practicable policies on forest conserving. These act as guides or plans of action in the process of conserving the forest.
5) Introduction of alternative energy sources, especially in rural areas, such as HEP, Solar energy and biogas so that people cannot put stress on the forest resources only as the source of energy.
6) The country should insist on the control of population growth since as the number of people grows explosively pressure is exerted on land leading to deforestation. The increased people in the population can cause clearing of land for cultivation or establishing new areas for settlement.
7) Destocking is another alternative. When the number of animals is reduced the rate of disappearance of vegetation is also reduce.
8) Changing agricultural methods from extensive to intensive farming system. Systems like shifting cultivation and nomadic pastoralism should be abolished and encourage farmers to settle in one area. Grazing of animals should be controlled and where possible zero grazing can be applied. This goes hand in hand with the viable improvement in science and technology in different communities in the country concerned like Tanzania.
9)There should be fund allocated for forest conservation activities. The fund can be used for conducting seminars, workshops and carrying out different training programs on different nature conservation strategies. The rural areas should be a major focus rather than the experts holding seminars and workshop in town. The seminars should not be aimed at merely generating income for the participants but should be for promoting the struggle towards curbing the problem of deforestation and sustaining the value of other resources.
10)There should be international cooperation among different countries in the world so as to facilitate forest conservation process. This is indispensable because deforestation, if not arrested or contained, can exacerbate catastrophic global issues.
11)Women empowerment is another very important aspect. Women have to be highly involved in the decision making process, supervision of the programs, and evaluation of the efforts and even in planting the trees. This is important because they are the major producers in many societies especially in the African countries. When they are empowered they can used resources judiciously.
12)The communities should cooperate in preventing the occurrence and spread of casual fires in the forest so as to bail trees out of the peril of being devastated.
13)There should be control of diseases that normally attack the trees and destroy them leading to disappearance of many species.
14)Industrial emissions should be controlled so as to avoid introduction of sulphur dioxide and nitrogen oxide into the atmosphere let acid rain is formed which destroys vegetation.
15)In areas with acidic soil liming should be used so as to reduce acidic condition so as to allow the growth of trees.
16)There should be introduced irrigation schemes in tree estates so as to ensure the smooth growth of trees to combat deforestation.
17)During lumbering, the trees should be cut selectively. So, people should avoid indiscriminate cutting of trees during lumbering and extraction of energy resources.
Problems faced during conservation process.
1) Lack of fund to be used in training people especially in rural areas.
2) Some people are adamant (rigid) to participate in tree planting because of ignorance.
3) When trees are planted, caring for the planted trees is another problem. Hence a big number of trees die due to lack of care.
4) Climatic vagaries also complicate the process of forest conservation. Trees can be planted but can end up drying due to lack of rainwater since in many parts, especially of the developing world, there are very few irrigation schemes.
5) Poverty is another problem. This makes people fail to afford other alternative energy sources and focus on trees. Due to poverty people find that using time in planting trees is wastage hence they go for other activities which can earn them a living.
6) Civil wars that lead to migration of people are another hindrance in combating deforestation. People forced to migrate to other places end up clearing the land, hence contributing to devastation of the forest.
7) Low level of technology is another problem. This forces people to use the land extensively leading to problems in combating deforestation.
8) Lack of coordination and cooperation between the government and even among the people they pose a great difficult in combating this environmental predicament. The alternative sources of energy are also expensive. For example in Tanzania HEP tariffs are high and the supply is not reliable. Most rural areas have not been electrified. These make people resort to the use of charcoal and firewood.
WILDLIFE (FAUNA)
Wildlife animals are of great importance to the economic and social development of any country. They importance can be erucidated as follows:
1) Animals provide food in the form of meat, which is the source of protein.
2) There are other valuable products from animals, which include wool, hides, skin, fur and tusks.
3) Wild animals attract tourists and are the source of foreign currency.
4) Wildlife conservation areas like Mikumi and Ngorongoro have created employment opportunities since there are hotels located in the National parks. Some people are employed as hotel managers, hotel attendants, drivers, guides etc.
5) Development of manufacturing industry for ornaments using the tusks and ostrich feathers.
6) Wild animals are used for researches in biological studies.
Problems facing the wil
dlife animals
dlife animals
1) Encroachment of wildlife areas by human being through establishing settlement and farms for cultivation.
2) Poaching is another problem. This involves illegal indiscriminate hunting within and around the areas designated for the wildlife animals.
3) Deforestation has led to the destruction of animals’ habitat in many places. Some trees die as a result of injudicious forest fires. Fires also kill some helpless animals leading to depopulation.
4) Water pollution by acid rain, agrochemicals etc, leads to water problems to animals.
5) Diseases attack animals leading to death of different animals in the conservation areas.
6) Drought is another problem. During drought there occurs scarcity of grass and drying of water bodies.
7) Floods are another problem. When floods occur many animals dies leading to depopulation.
Wildlife Management and Conservation
Wildlife management and conservation are the processes geared towards preserving wildlife animals so that they can help sustaining the current life dynamics and the life of the future generation. This kind of use is referred to as sustainable use of wildlife animals.
Why conserve or manage wildlife animals?
Why conserve or manage wildlife animals?
1) To avoid extinction of animals species most of which are very valuable. Future generations should also enjoy this resource.
2) To promote tourism in the country which is the source of income and employment
3) Animals enhance or expand our sphere of enjoyment, since they are a natural beauty.
4) To ensure reliable supply of some products like skin, wool, mohair, tusks etc.
5) To promote researches that help in different developmental aspects of the country.
6) Generation of income from wildlife helps in combating poverty in a particular country (Poverty alleviation).
7) To enhance the supply of food like meat, this is a source of protein.
8) Wildlife management helps in reducing environmental degradation.
The following measures should be undertaken to conserve wildlife animals;
1) There should be deliberate efforts to protect the natural vegetation, which provide food and habitat for animals.
2) There should be game cropping when there is overpopulation. This should be done systematically under good control. Game cropping helps to solve the problem of overgrazing.
3) Control of diseases in wildlife conservation areas and pastoral areas.
4) There should be formulation of game laws to regulate hunting. Where possible the game scouts should be introduced so as to ensure proper management of wildlife animals.
5) There should be intensification of the fight against poachers who kill animals indiscriminately.
6) Water pollution control in the wildlife areas should be undertaken.
7) In some places there should be established National Parks and Game reserves to protect a big diversity of fauna and flora.
8) Establishing water all through the year. This can involve the construction of dam.
9) Demarcating settlement areas and wildlife management areas. This can prevent people from unwarranted encroaching into the areas identified for wildlife preservation.
10) Involving the community on nature conservation so that they can be able to participate effectively and feel that they are part and parcel of the conservation programs.
WASTES AND WASTE MANAGEMENT
Wastes refer to the discarded or useless or unwanted matter that remains after the valuable components of the material have been used. Wastes can be toxic or no-toxic and hence harmful or harmless. They can be solid or liquid in nature. Solid wastes include crop remains, metals, rocks, glass products, wood, paper, food, coal products, and plastics. Liquid wastes include sewage (effluent) and hot water from the industries.
Sources of wastes;
The principal sources of wastes are household, industries, mining and farms.
1) From the households: – There come some food remains, metals like iron sheets, wood material, etc.
2) From the industries: – Emanate chemical wastes, hot water, metals, radioactive wastes, plastic material, paper etc.
3) From the farms: – Come some crop remains like maize cobs, husks, maize stalks, dung, etc.
4) From the mining areas: – Come some rock fragments and some chemicals.
Production of wastes and mismanagement has become a major issue in the world. Wastes are reduced in great quantities especially in the cities but they are poorly managed due to negligence, poor education, lack of cooperation, and lack of commitment. The increase in population and industrial development has been responsible for the increase in the rate of waste production.
Impacts of wastes;
1) Wastes lead to environmental pollution:
a. Air is polluted when they decompose giving out methane gas.
b. Water is polluted through sewage disposal in the water bodies. Hot water from industrial is also emptied in the water bodies leading to abnormal rise in temperature (thermal pollution)
c. Soil pollution due to surface run-off and dumping on the land.
2) Death of plants as a result of soil pollution especially addition of acids in the soil.
3) Keeping people uncomfortable due to the stinking of the decomposing wastes.
4) Radioactive material dumped in the soil lead to health problems and even death of people. Some people suffer from cancer or leukemia.
5) Outbreak of disease like cholera, typhoid, dysentery etc.
6) Wastes in the water lead to eutrophication (increase in nutrients) which later leads to the excessive growth of water weeds like hyacinth.
7) Destruction of the natural appearance and taste causing problems in water supply.
ENVIRONMENTAL ISSUES AND CONSERVATION
LIQUID ISSUES
1. Incineration of toxic wastes in special combustion furnaces in order that carbon dioxide can be given off rather than carbon monoxide which is more harmful.
2. Some of the liquid wastes should be neutralized by chemical process render them harmless.
3. Radioactive liquid wastes should be injected so deep in the rocks by a process called deep well disposal.
4. There should be a policy restricting people from disposing the liquid wastes in the water bodies and once found should be fined.
5. Secure landfills should be adopted in which the liquid wastes are filled in special drums and then dumped in the ground.
6. Treating the sewage before disposal is another proper alternative. This can be done through chlorination.
7. At an individual level there should be permeable pipes allowing slow escape of liquid wastes into the soil installed in the teaching field or absorption field.
8. Waste liquid material like water should be recycled. For example purifies water can be used for irrigation.
SOLID WASTES
Solid waste can be managed as follows:
1. Through dumping in open dumps. This is used where there are so many people like Dar es Salaam. The wastes are dumped in the large open pit like at Vingunguti in Dar es Salaam. But this method is not so good since it still leads to environmental pollution as the wastes can spread over the surface by wind or can produce gas when decomposing.
2. Sanitary landfills. This method involves dumping in the pit and then the wastes are covered with the layer of soil. This is better because the wastes can’t spread on the surface and air pollution is reduced since the wastes are confined in the pit.
3. Incineration: involves the burning of wastes at very high temperatures so that they can produce carbon dioxide rather than carbon monoxide.
4. Ocean dumping: Some of the wastes which can be dumped in the ocean are like food remains which are not toxic but not metals or wood materials. This can be done at a municipal.
5. Recycling: The wastes should be recycled rather than dumping. Garbage can be used as animal food, plastic material can be used. The best example is provided by the Coca-Cola and Pepsi cola companies who recycle their bottles. If was not for bottle recycling by these companies the bottles could have been extremely littered in many places leading to environmental pollution.
Other options;
1. Exchange of wastes between countries since some wastes in one country can be used in other countries like the second hand clothes.
2. Producing the plastics which are biodegradable so that once dumped can be decomposed.
3. Educating people on how to handle the wastes properly since some of them are harmful, as they can cause deaths.
4. Population control so that the rate of waste production can be reduced.
5. The dumping places should be located very far from the residential areas.
6. There should be cooperation between the individuals and the government in order to facilitate the waste management.
Constraints hampering waste management;
Some wastes are complicated to handle such as radioactive materials.
1. Poverty is another problem especially in the developing world since some of the measures need money especially for paying workers who are concerned waste management.
2. Poor organization and coordination of waste management activities.
3. Lack of commitment of the officials is another hindrance in the waste management process.
4. High population is another bottleneck since the big number of people leads to high rate of production of wastes.
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