Thursday, September 5, 2019

Land Degradation In The Nile River Basin Environmental Sciences Essay

Land Degradation In The Nile River Basin Environmental Sciences Essay Per capita availability is generally calculated by dividing total annual renewable water resources with population. While this could provide an accurate picture for countries with no dependency on external water resources, it does not provide an accurate depiction for countries with trans-boundary water resources. Taking into account the dependency ratio of the countries provides a much more realistic depiction of future water resources. For instance, Uganda has a 40.9% dependency ratio for its total annual renewable water resources (Rwanda, Burundi, Tanzania, DRC and Kenya contribute runoff into Lake Victoria). This will be impacted when increased water demand in upstream nations results in reduced water runoffs into Uganda. Egypt which originally had a 98% dependency ratio has been able to bring down its dependency by increasing alternate water resources but still has a 76% dependency ratio (55.5 BCM out of 73 BCM). Chapter 4 Land degradation is one of the challenges faced by several countries in the Nile River Basin. Land degradation comprises of any negative or undesirable change in the texture, content, moisture of land due to a combination of natural hazards and man-made activities. The African continent is characterized by 46% of extreme desert and 11% of land mass that is humid. Presently, in Africa around 250 million people are directly affected by land degradation while, worldwide 1 billion people in 100 countries are at risk of land degradation. The causes of land degradation are a combination of changes in the natural ecosystem, and the impact of the human social system, including human use and abuse of sensitive and vulnerable dry land ecosystems. Land Degradation in the Nile River Basin In Rwanda, around 71% of total land area is facing severe degradation and about 60% of its forest cover has been lost in the last two decades partly due to genocide, displacement and repatriation. Similarly, more than 30% of Burundi is severely or very severely degraded. In Tanzania, widespread land degradation is found in the highlands, especially on the slopes of Mt. Kilimanjaro. Kenya faced about 30% land degradation in 2002 and around one third of its population was directly dependent on degraded land by 2008. Also, land degradation is widespread in Kenya, affecting 20% of all cultivated areas, 30% of forests, and 10% of grasslands. Uganda faces land degradation and erosion covering 60% of its total land area, the majority of which is in the highlands of the South-west. Ethiopia also faces land degradation mostly in its highlands, especially in the Amhara region. It is estimated that Ethiopia loses 4% of its GDP due to land degradation. In Sudan, approximately 1,200,000 km2 of land has degraded in varying degrees. The most degraded zones are the arid and semi-arid regions in the Northern half of Sudan where 76% of the countrys population resides. In Egypt, the North-western delta faces highest degradation due to contamination and increased salinity. Common Causes of Land Degradation in the Nile River Basin Some of the causes for land degradation in the Nile River Basin are as follows: Population Pressure: Growing population in the Nile River Basin countries puts immense pressure on land and its resources leading to severe degradation and reduced outputs. For instance, the majority of the population in Egypt and Burundi, 98% and 58% respectively, live in the Nile Basin. In Kenya, 70% of the population lives in 12% of the countrys land area which is suitable for rain-fed cultivation, thereby putting immense stress on its resources. Deforestation: The most common cause for land degradation in the Nile River Basin is deforestation. To adhere to the needs of growing population, forests are cleared and there is immense pressure on its resources. In Rwanda, the forest area was reduced to 4700 km2 from 7000 km2 post the genocide in 1994. Deforestation also took place due to increased need for wood to construct makeshift shelters for displaced people and for cooking. Bushfires have also become common especially in the dry seasons in the Eastern and South-eastern regions of Umutara, Kibungo and Bugesera. In Burundi, the rate of deforestation in high due to increased dependency on wood for fuel. The forest cover declined from 11.3% in 1990 to 5.9% in 2005. In Tanzania, deforestation is severe in areas populated with refugee populations. Also, wild fire is common in its grasslands. Between 1990 and 2005, Uganda lost one-third of its forest area due to deforestation. It is estimated that at this rate, Uganda will not have any forests by 2055. Uganda loses around $ 200 million annually due to deforestation. Deforestation is a major factor for land degradation in Ethiopia. While the forests once covered 65% of the country and 90% of the highlands in Ethiopia, by 2001 they were reduced to 2.2% and 5.6% respectively. The Blue Nile basin faces such severe deforestation that very little forest cover remains in the region. The forest coverage fell from 16% to 2% in the 1980s itself. Over Grazing: The demand for livestock is high in the Nile River Basin. Cattle farming leads to over grazing in fertile lands, depleting its quality and productivity. In Rwanda, over grazing is observed in range-lands especially in the North-west parts of Umutara. In Tanzania, over grazing is witnessed mostly in the Lake Victoria Zone and parts of Northern Tanzania. Over grazing accounts for 75% of the total degraded land in Sudan. In Uganda, the cattle corridor has most of its land degraded due to over grazing from Moroto and Kotido in the North-east through Luwero and South to Masaka and Mbarara. Leaving aside the North, most of the Corridor is seriously degraded. Lack of Awareness: Improper farming practices, poor soil management policies due to lack of awareness also lead to land degradation in the Nile River Basin. For instance in Rwanda, only 36.6% of the total land had soil protection structures in 2005 as compared to 83% in 1998. Climate Change: Climate change is another factor due to which there is immense land degradation. Increasing instances of floods and droughts lead to wide spread land degradation. There are various forms of land degradation. These include Soil erosion and sedimentation Surface runoff and floods Desertification and loss of natural vegetation Sand encroachments Sedimentation and Soil Erosion Sedimentation has three stages. It starts with soil erosion which is essentially the removal of top soil which is then transported and deposited in different locations depending upon the flow of water or wind or gravity. Some of the causes of sedimentation include deforestation which reduces water retention thereby increasing soil erosion; floods and droughts; and changes in river flow. Sedimentation in the Nile River Basin is witnessed the most in the Nile Equatorial Region, Blue Nile catchment and the coastal belts. Wide spread deforestation has a detrimental impact on the sedimentation levels in the Nile Equatorial Lakes and leads to increasing soil erosion. The siltation of the Nile Equatorial Lakes if combined with unusually high rainfall could lead to a rise in the lake levels which could in turn lead to flooding. The key problem sites for soil erosion in the Lake Victoria Basin are the Kagera River and the Nyando River in Kenya. Due to its topography and torrential rainfall, the Blue Nile catchment faces high rates of sedimentation as compared to the White Nile, whose sedimentation is largely retained in the Equatorial Lakes and the Sudd region. While the Nile catchment runoff is estimated at a low rate of 5.5%, the ratio of the runoff of the Blue Nile catchment on its own is 20%. Sedimentation has a negative effect on reservoirs built along the Nile River Basin. It clogs the area thereby reducing the amount of water that can be stored. Rwanda Around 40% of land in Rwanda is at high risk of erosion, 37% requires soil retention measures before cultivation, and only 23% is erosion free. Data from field research stations report soil losses between 35 246 tonnes per hectare annually, amounting to losses costing about 3.5% of Rwandas agricultural GDP. The Nyamitera River delivers 567,000 tonnes of particles in a matter of five flood days to Rwanda, of which more than half is the annual suspended sediment yield of its Nile Basin region. Increasing use of land for tea cultivation is also leading to sedimentation in Rwanda. The Mulindi tea plantation in Gicumbi district uses fertilizers that cause soil degradation, water pollution and deforestation, which in turn results in soil erosion, floods and sedimentation in the valley. Burundi Deforestation, over grazing and agricultural expansion into marginal lands are the main factors leading to soil erosion in Burundi. The sediment yield of Burundi and its contribution to the Nile basin is presently unavailable. Sedimentation causes many problems in Burundi including blocking inlet channels of pump irrigation schemes, clogging hydropower turbine areas, corroding pumps among others. Tanzania The main type of erosion witnessed in the Lake Victoria Basin in Tanzania is sheet erosion where a uniform thin layer of top soil is washed away. In Tanzania, 61% of land area faces soil erosion with a topsoil loss of 100 tonnes per hectare per annum. Highest soil loss within the Lake Victoria Basin is from cropland which loses 93 tonnes per hectare annually, followed by rangeland losing 52 tonnes per hectare each year. Additionally, there has been soil loss in Shinyanga, Dodoma, Morogoro, and Arusha. Also, Kagera Basin is vulnerable to soil erosion and leaching of nutrients due to its high population and poverty levels. The Masalatu Reservoir constructed on Simiyu River receives an annual sedimentation yield of 406 m3/ km2 or 1.43 tonnes per hectare. Kenya The Nyanza province bordering Lake Victoria is undergoing rapid catchment deterioration due to frequent droughts, deforestation and old agricultural practices. This results in Kenyas high sedimentation load contribution to Lake Victoria Basin through its tributaries. 61% of the basin area contributes to soil sedimentation at a rate of 43 tonnes per hectare each year, whereas the rest of the basin forms a sink area where sediments are collected. Due to high sedimentation on the bed, the rivers Nyando, Nzoia and Sondu, and other tributaries emptying into Lake Victoria are prone to flooding. Surface runoff in wet season causes sheet, rill and gully erosion. Wind causes erosion in dry season. Nyando River experiences severe gully erosion due to heavy water runoff. The removal of the top soil is very high ranging from 90 tonnes per hectare annually in degraded areas, to 67 tonnes per hectare elsewhere. Uganda Major source of soil erosion to the Lake Victoria Basin is the Kibale River at 0.06 tonnes per hectare annually. Runoff in sub-catchment of Bukora is the main reason for causing soil erosion. Soil loss rates are the highest on bare soils, followed by annually cultivated land, degraded range lands and perennially cultivated land. Lake Albert is also under threat of siltation due to inflows from Kyoga Nile, as well as Semliki River which carries sedimentation from DRC. It is estimated that 4% 12% of GNP is lost from environmental degradation, of which 85% is through soil erosion, nutrient loss and crop changes. Also, the rate of soil fertility depletion in Uganda is one of the highest in Sub-Saharan Africa. Ethiopia There is high erosion in the Ethiopian Highlands. Around 1900 million tonnes of soil is eroded annually at an average of 100 tonnes per hectare. Also, up to one billion tonnes of top soil is lost each year. The Highlands face severe types of soil erosion including sheet, rill, gully and wind. It also witnesses stream bank erosion, biological, physical and chemical degradation Blue Nile is the major contributor of sedimentation during the flood season, contributing approximately 125 million tonnes, while the Atbara contributes roughly 50 million tonnes. The flows of the Blue Nile are unregulated until they arrive in Sudan leading to an enormous amount of sedimentation at the Roseires Dam. With increased deforestation and agricultural activities along the banks of the Blue Nile, there is a substantial amount of debris added to the flow which is carried downstream. The proportion of runoff to sedimentation is higher for the Atbara River which is due to its geographic location in a drier region than the Blue Nile and also due to a relatively longer period of dry season followed by heavy rainfall in a relatively short period. Sedimentation peaks three weeks before rainfall peaks as rainfall washes away soil loosened due to loss of moisture during the dry season. A decline in crop yields has been witnessed at a rate of 1 to 3% on cropland and 2.2% in Ethiopian highlands. It is estimated that the cost of land degradation due to soil erosion to Ethiopia could be about $2 billion in 25 years or $80 million each year. About 80% of the losses are from reduced crop production and 20% from reduced livestock production. Soil nutrient depletion reduces crop production by 885,330 tonnes annually amounting to losses of around 14% of agricultural contribution to Ethiopian GDP. Sudan Soil erosion is leading to rapid siltation and loss of functionality of reservoirs and irrigation schemes in Sudan. The small reservoirs get silted quicker. Irrigation schemes are witnessing major damage due to siltation which is leading to a reduction in water transported to crop lands. For instance, crop water requirements are no longer met in the Gezira and Rahad irrigation schemes. River band erosion along the Blue Nile River has been witnessed with most affected areas lying downstream of Roseires Dam, Singa to AlSuki. River widening in the region also leads to bank erosion where irrigable land is lost as has been witnessed in the main Nile and Atbara River sections. Around $1.5 million worth of economic losses have been witnessed via the loss of mature date palm trees as a direct result of bank erosion. Egypt The Nile Bank is witnessing bank erosion due to the corrosive action of sediment free waters as witnessed in Sudan past Roseires Dam. Agricultural land is depleting at a rate of 13,000 hectares on an annual basis due to bank erosion. Increase in coastal erosion and extensive erosion of the Nile Delta is being witnessed due to lack of sedimentation and increase in salinity levels. Sedimentation in Reservoirs Sedimentation is the single greatest problem reservoirs face in maintaining their functionality for water storage, as well as for hydropower generation. Hydropower generation is reduced during peak sedimentation periods as debris gets caught in the turbines and need to be shut down for cleaning. Sedimentation stuck in the cooling mechanism of the hydropower plant leads to loss of efficiency in energy generation and also requires shutdown for repair. Also, silt adds to the wear and tear of the plant which decreases the lifespan of the machinery, depending on the abrasiveness of the mineral content in the silt. Hydropower generation is often stalled during floods to clean turbines and prevent damage resulting in very low power generation during flood season. Sedimentation also leads to reduced water storage capacity which results in less water for irrigation and cost of construction to raise the dam to maintain storage capacity. Currently, the cost of clearing sedimentation is prohibitive at $625 million ($5 to clear 1 m3 of silt, about 125 MCM is being cleared per year). Roseires Dam The primary mandate of the Roseires Dam is to ensure that runoff levels are maintained to meet irrigation and water storage requirements. The Roseires Dam is losing considerable parts of dead water storage capacity, as well as live storage capacity. In 1966, its storage capacity was 3,329 MCM which has been reduced to 1,920.89 MCM as of 2007, leading to a 37% decrease in storage capacity. The Roseires Dams height has been elevated in order to mitigate losses in functionality and another elevation project is being currently discussed. Aswan High Dam in Egypt Aswan High Dam has 100% trap efficiency of sedimentation which means that waters are almost perfectly sediment-free beyond the Aswan High Dam. Sedimentation transported to the reservoir and deposited there is practically negligible from December to June, peaking from July to September, reducing in October and November to none in December. Aswan High Dam is losing considerable part of live storage capacity, as opposed to dead storage capacity which was designed to absorb sedimentation. The reservoirs total operational span has been reduced to 362 years from an initial estimate of 500 years as a result of sedimentation. Desertification The African continent, with the Sahara desert in the North and the Sahelian belt below, is vulnerable to desertification. This condition is exemplified with increasing instances of drought and famines. The causes of desertification are complex, including both direct and indirect factors such as: Cultivation, inappropriate agricultural practices and overgrazing Unsustainable animal husbandry and pastoralism Climate change including reduced rainfall Population growth pressures Poor land use and management practices Lack of soil and water conservation structures; Removal and loss of vegetation; Deforestation and land clearing; Total dependency on natural resources for survival; Human activities comprising technological agents (water pumps, boreholes, dams) and institutional mechanisms and policies. Desertification in the Nile River Basin East and South-east regions of Rwanda show increasing desertification trends due to increase in population and migration leading to over exploitation and degradation of land. People from densely populated provinces in the North, for instance Ruhengiri, Gisenyi and Byumba, and Butare and Gitarama in the South, are moving towards the least populated provinces in the East including Umutara, Kibungo, Kigali and Ngali in the South East. In Burundi, the area of Imbo witnesses long dry spells leading to a gradual decrease in water resources, especially in the levels of Lake Tanganyika with a tendency towards desertification. Since 1999, there has been a strong variability of rainfall with a tendency for a long dry season from May to October (6 months) in the lower altitude outlying areas like Kumoso, Bugesera, and Imbo. In Tanzania, the main reason for desertification is expanding agriculture rather than overgrazing by pastoralists. Around 33% of Tanzania is affected by desertification. The coastal areas face pressure from intensive cultivation and fuel wood gathering. In Kenya, 80% of its area is estimated to be threatened by desertification with up to 30% of the population affected by desertification and drought. Drought and increasing population are key factors that enhance desertification in Kenya. The Nyika Plateau and the Coastal Region are affected and threatened most by desertification. Also, the woodlands are prone to drought and desertification, primarily due to slash and burn methods of land preparation. Kenyas drylands occupy 88% of the land surface area, and have a population of 10 million people. Approximately 50% of livestock and 70% of wildlife are located in these drylands. In Uganda, the North-east, especially the Cattle Corridor has been witnessing overgrazing, soil compaction, erosion and the emergence of low-value grass species and vegetation which have subdued the lands productive capacity, leading to desertification. Some dryland districts like Moroto, Nakasongola, Karamoja and Kakuuto in Rakai are experiencing desertification. Around 71% of Ethiopian land is prone to desertification including its highlands and lowlands. The Rift Valley suffers immense desertification and land degradation. Desertification threatens Ethiopias agricultural productivity, wherein more than 80% of the population depends on various forms of agricultural production. Also, 95% of the farms are small-scale and depend on rain-fed agriculture. Ethiopia suffers a loss of $139 million per year due to reduced agricultural productivity. Sudan and parts of Egypt are more prone to desertification in the Nile River Basin. Egypt has experienced accelerated desertification of rangelands in the last few decades. Presently, 45% of rangelands are severely degraded, 35% are fair, 15% are good, and 5% are excellent. It is reported that 11,000 hectares of land has been lost due to desertification. Parts of Western Egypt fall into the Sahara and are hot and dry areas which are extending into the mainland. Increasing evaporation has also led to drying out of one of the Toshka Lakes. Egypt witnesses various forms of desertification such as: Degradation of irrigated farmland due to low quality water in irrigation Degradation of rain-fed farmland (Northern coastal belt and Northern Sinai) Degradation of rangeland (Northern coastal belt) through overgrazing, plant covers degradation Sand Encroachments from the Western desert on the Nile Valley land (Southern Egypt) and on the High Aswan Dam reservoir (in Egypt and Sudan). Desertification in Sudan In terms of desertification, Sudan is the largest and most seriously affected country in Africa. The arid and semi-arid lands cover an area of 1.78 million km2, constituting around 72% of the total area of the country. There is moderate to severe land degradation in the desert and semi-arid regions in the Northern half of Sudan. The Western part of Sudan (in the Sahel region) is most prone to drought and increasing desertification, especially the states of Darfur, Kordofan, Khartoum and Kassala. The total desertification between Darfur and Kordofan is 22% i.e. 200,000 km2. A decline in precipitation has caused a stress factor on pastoral societies in these two regions, thereby contributing to conflict. There is a very strong link between land degradation, desertification and conflict in Darfur. In northern Darfur, increasing population growth, lack of resources and environmental stress led to conflicts which were further sustained by political, tribal or ethnic differences. As a consequence of desertification in Darfur, there has been increased mortality due to famine and disease, a decrease in total water and land availability, quality of water and land (including fertility), production of major staple foods, and deaths of domestic animals. It is estimated that since the 1930s, there has been around 50 to 200 km Southward shift of the boundary between semi-desert and desert. This boundary is expected to continue to move Southwards due to declining precipitation. The remaining semi-desert and low rainfall savannah, which represent 25% of Sudans agricultural land, are at considerable risk of further desertification and could lead to a 20% drop in food production. Sand Encroachment Instances of desert encroachment in Sudan are increasing, whereby the entire strip of the country along the Nile especially between Delgo and Karima in Northern Sudan is threatened. Sand dunes on the Eastern bank of River Nile in Sudan and encroachments in North-central regions can threaten the rivers course. Sand encroachment is also affecting the productivity of soil which has been witnessed extensively in the Gezira scheme and also in some areas of North Kordofan, North Darfur and Kannar in the Northern State, Sudan. In the Dongola-Merowe region of Sudan, the area covered by sand dunes increased from 51.2 km2 to 61.2 km2 between 1976 and 1996 and decreased to 35.1 km2 in 2000. This decrease could be attributed to an increase in the area covered by gravel and/or coarse sand. In Egypt, active sand dunes and encroachments occupy more than 16.6% of the countrys total land area. Sand encroachment in Egypt is further enhanced by the erratic rainfall, active winds, and scarcity of plant cover. Some inactive sand accumulations have been noticed in the Eastern side of the Nile delta and in the Sinai Peninsula. Types of Desertification Processes Underway in Sudan Climate-based conversion of land types from semi-desert to desert The least drought resistant vegetation fails to survive and reproduce. For instance, in Northern Darfur and Northern Kordofan, this is manifest in the widespread death of trees during drought events which are not followed by recovery. The desert climate is estimated to move Southward by approximately 100 km over 40 years. Degradation of existing desert environments, including wadis and oases At least 29% of Sudan is desert, within which there are hundreds of smaller wetter regions resulting from localized rainfall catchments, rivers and groundwater flows. It was discovered that all these areas were moderately to severely degraded, primarily due to deforestation, overgrazing and erosion. Conversion of land types from semi-desert to desert by human action Activities such as deforestation, overgrazing and cultivation result in habitat conversion to desert, even though rainfall may be sufficient to support semi-desert vegetation. One of the problems is the conversion of dry and fragile rangelands into traditional and mechanized cropland. Chapter 5 Water Quality Several factors pollute Nile waters, in particular faecal coliform bacterial contamination caused by lack of sanitation facilities and a high dependence on pit latrines, leading to presence of animal and human waste alongside open water bodies. Additionally, agricultural fertilizers and pesticides discharge high concentrations of nutrients and phosphates that runoff and leak into ground and surface water. Also, chemical pollution from industrial waste, mining activities and domestic sewage are released into water bodies without any effective wastewater treatment. Furthermore, sedimentation and siltation caused by deforestation, land degradation and soil erosion impact overall water quality. Lastly, poor planning practices, weak infrastructure and inadequate wastewater treatment systems add to the untreated water discharge. Some of the impacts of water pollution are death and destruction, loss of livelihood and income, and health hazards. The problem with a transboundary water resource in terms of water quality is that, polluted water from one area flows into the other area. This is specially witnessed in the Lake Victoria Basin. Water Hyacinth is another transboundary issue between the countries as it has a tendency of spreading fast and also leads to increased evaporation. Pollutant loads are washed away along with runoff and sedimentation loads which lead to water quality deterioration further downstream, rendering it non-viable for drinking purposes. Rwanda The main sources of water pollution are domestic, commercial, industrial, agriculture, water hyacinth and mismanagement of wetlands. Due to increased population and agricultural practices, inadequate sanitation facilities, there is an extensive use of fertilizers and pesticides. Also, wastewater from rural towns and villages containing faecal pollution are left untreated, giving rise to water borne diseases. In River Nyabugogo, there have been high rates of Iodine at 7.62m per litre. Additionally, there are large concentrations of Copper at 1.3mg per litre, Fluoride at 1.85mg per litre, Ammonia at 1.7mg per litre and Sodium at 105.3mg per litre. Also, Hexavalent Chromium was found ranging between 0.09 to 0.28 ÃŽÂ ¼g per litre. Although the Rwandan Ministry of Lands, Environment, Forest, Water Mines (MINITERE) and ELECTROGAZ have laboratories in place for water monitoring, the data is insufficient. The water drinking standards have been defined but have not been adopted yet. As a result of eutrophication by water hyacinth and agricultural pressure, Lakes Mihindi and Muhazi in Southern Rwanda are diminishing in size. Burundi There are several types of water pollution including bacteriological pollution from animal waste, organic pollution due to waste effluent from coffee processing plants, and industrial pollution via chemical fertilizers such as nitrates, phosphates and pesticides. Some of the causes of pollution are high demographic density, lack of latrines and waste dumping, and mining activities resulting in discharge of heavy metals and arsenic, especially in River Kanyarus tributary, Nowgere. Bujumbura accounts for 90% of industries in Burundi. However, data regarding industrial pollution is unavailable and not much has been achieved in monitoring and managing water quality due to under-resourcing of laboratories. Tanzania The water quality in Tanzania is affected by natural factors and human activities. The former comprises high fluoride concentrations and salinity in natural waters. The latter includes discharge of municipal and industrial wastewater, run-off from agricultural lands, and erosion encompassing high concentrations of nutrients, pathogens, BOD and COD levels. Additionally, gold mines in the Lake Victoria Basin consist of heavy metal pollution. Tanzania has no comprehensive national program for monitoring the quality of water or pollution even though water utility companies are required by law to monitor the water source and quality of water they supply. Kenya Water pollution in Kenya is caused by point and non-point sources such as agricultural activity, urbanization, industry, leachates from solid waste tips, sediments, salts, fertilizers and pesticide residues. Additionally, municipal sewerage plants discharge untreated wastewater into surface watercourses, causing significant health hazards and localized eutrophication. Tanneries, pulp and paper mills, coffee processing factories, breweries and sugar cane processing facilities do not have effective wastewater treatment plants and their effluents contribute organic loads, heavy metals and other toxic substances. The point pollution sources include sugar, paper, and fish industries, and also municipal sewage, oils and lubricants, marine workshops, petrol stations, human wastes and refuse from market and urban centres and fishing villages. The main non-point pollution sources comprise high nitrate, phosphate and pesticides from poor application of agricultural chemical and soil erosion. The Kenyan Lake Victoria Basin has a population of 12 million people and a low depth of approximately 6 meters, thereby causing an inability of catchment areas to perform purification of water. Although only 8% of Lake Victoria falls into Kenyan territory, tributaries such as Sio, Nzoia, Yala, Nyando and Mara are already severely polluted and contribute further to the lake pollution. Uganda The increased demand and use of pesticides, fungicides, herbicides and fertilizers is impacting the water quality in Uganda. Agricultural practices account for 50% of nitrogen and 56% of phosphorus into the Lake Victoria Basin. Additionally, the exploitation of petroleum threatens the overall ecosystems of Lake Albert and Edward Basins. The Northern end of Lake George, Uganda, and its associated wetlands receive localized metal pollution from a former copper mine and tailings left after metal extraction. There is a

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.