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LIST OF TABLES
LIST OF FIGURES
ACRONYMS AND ABREVIATIONS
1.1 BACKGROUND OF THE STUDY
1.2 STATEMENT OF THE PROBLEM
1.3.1 General objective
1.3.2 Specific objectives
1.4 RESEARCH QUESTIONS
1.5 SCOPE OF THE STUDY
1.6 SIGNIFICANCE OF THE STUDY
1.7 DEFINITION OF THE KEY TERMS
1.7.2 Climate change
1.7.3 Land degradation
1.7.5 Water potential
2.0 LITERATURE REVIEW
2.1 Climate change impacts
2.2 Causes of wetland degradation
2.2.1 Human cause
2.2.2 Natural cause
2.3 Forms of wetland and soil degradation
2.4 Consequences of climate change impact on wetland water resources
3.1 AREA OF STUDY
3.2 RESEARCH DESIGN
3.3 PHYSICAL ENVIRONMENT
3.3.1 DRAINAGE AND TOPOGRAPHY
3.3.2 CLIMATE AND VEGETATION
3.4 SAMPLING TECHNIQUES
3.5 DATA COLLECTION
3.5.1 PRIMARY DATA COLLECTION
3.5.2 SECONDARY DATA
3.6 DATA ANALYSIS
3.7 LIMITATIONS OF THE STUDY
PRESENTATION AND DISCUSSION OF FINDINGS
4.1 Climate change impacts in the region
4.2 CAUSES OF WETLAND DEGRADATION
4.2.1 Human cause
4.2.2 Natural causes of wetland degradation
4.3 Forms of wetland and soil degradation
4.4 Consequences of Climate change impact on wetland water resources
5.0 SUMMARY, CONCLUSION AND RECOMMENDATIONS
Appendices I: Research questionnaire
Great gratitude goes to my parents Mr. Kunya David and Mrs. Nabirye Edith who gave me support both parental and economic for the whole of my life and even during all my academic years at Makerere University and whenever I was out for the practical courses particularly when carrying out my internship and when collecting data for my dissertation. To my friend Naturinda Rachael who gave me moral and courage whenever trouble poured on me, thank you very much. From the bottom of my heart, I give great thanks to my supervisor Mr. Nseka Denis Galende for his knowledge and coordination. Huge appreciation goes to Mr. Aram Thomas the District Environment Officer Mayuge (D/EO), the Head of the Natural Resource Office Mr. Lubanga Musa, Forestry officer Mr. Waiswa David, the Mayuge District Health Inspector Mr. Gidudu, Health officer Mayuge Town council for providing me with necessary information, coordination and expertise they rendered to me which contributed to the success of my research. I will also thank all the locals who gave me attention during the session of gathering data in the fields of research.
Great appreciation goes to the Department of Geography, Geo-informatics and Climatic Sciences, for the theoretical practical educational skills and all the assistance rendered to me throughout the course. Above all great thanks go to the Almighty God who gave me the gift of life and made me strong during unbearable times both at University, during my research and whole education life. May the almighty reward all of you abundantly!
I hereby dedicate this work to my beloved parents Mr. and Mrs. Kunya David and Nabirye Edith, for their generosity, financial and moral support during my stay at the University. You are my strength, my determination, wisdom, my heart without you I would lose all the concentration and probably fall apart. To all my friends most especially my wife Naturinda Racheal, Waiswa Yeseri, Odora David, and many others who supported me during times of financial crisis. Special thanks goes my supervisor Mr. GalendeNseka Denis Amooti and his senior student Opedes Hosea, Dr. Musaali Paul, Dr. Bob Nakileza and Mr. Nadhomi Daniel who consistently guided me on how to come up with all this work. Thank you very much and I will live to remember your good efforts to shaping me into an academia. And also to the readers of this work, both students and other people who may read it for research purposes, that may you understand as you read it. Above all to the almighty God who gives me Wisdom, Protection and enabled me to reach this as one of my dreams in life.
The study focused on examining the impacts of environmental change on the water potential of Bugingo wetland water resources in Mayuge District. The data analyzed from the study were based on objectives and research questions. These were; to identify the major climate change impacts in the region; to identify the major causes of wetland degradation; identify the forms of wetland degradation and to examine the influence of climate change impacts on wetland water resources. Data was collected in all the three parishes using systematic random sampling among the farmers. Observation and use of transect walks across the wetland were the major ways of data collection where two plot of 200m one within the wetland and one on the flanking hill. A random sample of 25respondents was selected for interview purposes. Measurements of gulley erosion, rill erosion were obtained and tabulated during data collection.
It was mainly found out that, the environmental change impacts involved both the climate change and all the land degradation processes that threaten the existence of water resources in the wetland which is increasingly becoming a threat in the area. In conclusion, Environmental change impacts cause wetland degradation and water storage capacity in the region as per the analysis. Therefore, the establishment of a broad network comprised of wetland scientists, climate change scientists, economists, the public, agricultural community, land-use planners and policy makers. This is the one of main suggested solutions to the problem since it can create routes through which information and research results are communicated regularly as observed in chapter five.
Table 1: showing the volume of gulley erosion measured on the three slope facets of Ikulwe hill south of the wetland
Table 2: Volume of rill erosion on the slopes of Mayuge hill North of the wetland
Table 3: Shows PH tests of water taken from three samples.
Figure 1: A bar graph showing the intensity of gulley erosion by volume on Ikulwe hill slopes flanking Bugingo wetland as shown in table 1.
illustration not visible in this excerpt
Environmental change refers to the alteration or disturbance of the environment making it unable to sustain most of the ecosystems. It is mainly manifested in form of land degradation and climate change (Carla 1995). Mannion (1997) defines environmental change as the dynamic systems of energy and material transfer that operate on global scale to bring about gradual and sometimes catastrophic transformation of the atmosphere, hydrosphere, lithosphere and hydrosphere. According to Morgan (1986), land degradation is majorly caused by human activities such as poor waste disposal and poor agriculture methods. Climate change can be explained as the change in a state of climate that can be identified both basing on physical signs and using statistical tests by changes in the mean or the variability of its properties and that persists for an extended periods (UN-HABITAT 2011).
Climate change may be due to natural processes or to persistent anthropogenic changes in the composition of atmosphere or in land use. Therefore climate change can also be understood as the persistent increase in the length of normal intervals of climate variance. Climate variability refers to the variations in the mean state and statistics of climate on all spatial and temporal scales beyond that, of individual weather events. According to Harvey (2000), the geological record shows that the earth’s climate has changed though out the earth’s geological history. It is known that the earth has become warmer over the last century. The Intergovernmental Panel on Climate Change (IPCC 1996), a group established by the World Meteorological Organization (WMO) and the United Nations Environment Program (UNEP), reports that the average surface temperature of the earth has increased during the twentieth century by about 0.6° ± 0.2°C. (The ± 0.2°C means that the increase might be as small as 0.4°C or as great as 0.8°C.) This may seem like a small shift, but although regional and short-term temperatures do fluctuate over a wide range, global temperatures are generally quite stable. In fact, the difference between today’s average global temperature and the average global temperature during the last Ice Age is only about 5oC. Indeed, it’s warmer today around the world than at any time during the past 1000 years, and the warmest years of the previous century have occurred within the past decade.
IPCC (1996) reported North America is experiencing decreasing snowpack in the western mountains; 5-20%increase in yields of rain-fed agriculture in some regions. There is also increased frequency, intensity and duration of heat waves in cities. In Latin America, there is increasing gradual replacement of tropical forest by savannah in eastern Amazonia. There is risk of significant biodiversity loss through species extinction in many tropical areas and significant changes in water availability for human consumption, agriculture and energy generation. In Europe, there is increased risk of inland flash floods; more frequent coastal flooding and increased erosion from storms and sea level rise; glacial retreat in mountainous areas; reduced snow cover and winter tourism; extensive species losses; reductions of crop productivity in southern Europe. In Asia , Freshwater availability is projected to decrease in Central, South, and East and Southeast Asia by the 2050s.Coastal areas will be at risk due to increased flooding; death rate from disease associated with floods and droughts are expected to rise in some regions. In Africa , by 2020, between 75 and 250 million people are projected to be exposed to increased water stress; yields from rain-fed agriculture could be reduced by up to 50% in some regions by 2020.Agricultural production, including access to food, may be severely compromised.
According to Erwin (2009), Global climate change is recognized as a threat to species survival and the health of natural systems in Africa. Scientists worldwide are looking at the ecological and hydrological impacts resulting from climate change. Climate change will make future efforts to restore and manage wetlands more complex. Wetland ecosystems are vulnerable to changes in quantity and quality of their water supply, on the vegetation and the living organisms. It is expected that climate change will have a pronounced effect on wetlands through alterations in hydrological regimes with great global variability. A Wetland is an area of land whose soil is saturated with moisture either permanently or seasonally. Such areas may also be covered partially or completely by shallow pools of water. Wetlands include swamps, marshes, and bogs, among others. The water found in wetlands can be saltwater, freshwater, or blackish. Wetlands cover 6% of the world’s land surface and contain about 12% of the global carbon pool, playing an important role in the global carbon cycle (IPCC 1996). According to Balek (1977), water availability in Wetlands is associated with the spatial and temporal dispersion, flow attributes on surface and ground water in its reservoirs. Based on hydrology, wetlands can be categorized as riverine (associated with streams), lacustrine (associated with lakes and reservoirs), and palustrine (isolated). Sources of water flows into wetlands are, surface runoff, and sub-surface water outflow. Hydrodynamics (the movement of water through and from a wetland) affects hydro-periods (temporal fluctuations in water levels) by controlling the water balance and water storage within a wetland. Wetland ecosystems include both permanently wet areas and areas that are wet only in cycles or during part of the year. Wetland ecosystems without trees are called Marshes whereas wetland ecosystems with trees are called swamps.
The impacts of climate change are now visible everywhere especially in Mayuge district where wetlands have been degraded. Uganda will suffer severe effects of climate change mostly areas bordering Kenya where Mayuge district is located and North-western Uganda . This calls for further research on the impacts of environmental changes on the wetlands in Mayuge. The District has the wetland ecosystems being encroached due to the population pressure that have led to degradation on the slopes surrounding these wetlands through clearing them for agriculture and the climate change impacts has not helped the situation. Continued degradation will reduce the hydro periods and water availability making flora and fauna of most swamps die away. But the government cannot effectively check on this continuing degradation of wetlands in the area due to climate change coupled with human encroachment unless systematic studies are conducted in the area. A study to describe and analyze facts about climate change impacts on the water potential and describe the existing situation on the wetlands is highly needed in this region.
In Busoga areas (South east of Uganda) particularly Mayuge district, the major climate change impacts that have affected the area include; increasing occurrences of long droughts, and increasing temperature erratic rains, change in the rainfall patterns and variability. There is less water delivery into the wetlands due to reduced underground water recharges of the surrounding hills. The situation has not been helped by the degraded wetlands. The wetlands can no longer store and keep water for the ecosystems. This therefore spells out danger on the future water potential of the wetland and the entire region. This will result into reduced water purity and quantity in future in the region. This shows that the region is going to experience water scarcity and crisis with time to come. This study therefore aimed at exploring the major climate change impacts affecting the region. It also identified the major wetland degradation processes in the region. The study further examined the influence of the climate change impacts on water storage capacity of the wetland. The study finally identified some feasible measures of improving the water storage capacity of both wetlands and the flanking hills.
1. To examine the impacts of environmental change on the water potential of Bugingo wetland and the surrounding area in Mayuge District
1. To identify the major climate change impacts in the region.
2. To identify the major causes of wetland degradation
3. To identify the forms of wetland degradation.
4. To examine the influence of climate change impacts on wetland water resources.
1. What are the major climate change impacts in the region?
2. What are human causes of wetland degradation and poor water storage?
3. What are the major natural causes of wetland degradation and poor hydrology?
4. What are the major forms of wetland degradation?
5. What is the influence of climate change impact on water storage capacity of the wetland?
The study was conducted within the wetland system of Bugingo. Bugingo wetland system is located in Mayuge district. The swamp is bordered by Mayuge town hill in the North which is approximately 1,184m above sea level and Katwe Hill which is approximately 1,180m high. It is surrounded by villages including Bugingo in Mayuge town council, tsetse zone in Mayuge town council, Budhebera in Kavule parish, Katwe in Ikulwe parish and DFI 1in Kavule parish. It flows from West to East crossing Bugadde-Mayuge road. Bugingo wetland has a series of multiple streams that surround almost all parts of Mayuge Town council. In the study, major climate change impacts were identified through observation, interviewing, sampling, transect walks and reading documents from the environment offices both at the district and other offices. These among others were increased temperatures, prolonged droughts, erratic rains and other impacts. The study also identified the forms and causes of wetland degradation such as bush clearing, severe soil erosion, charcoal burning and others. The study examined the influence of climatic change impacts on water storage capacity of the wetland and found out that change in climate directly affects the amounts of water available in the wetland. This was done through observation, picking sample points across and transects walks along the wetland and flanking slopes and other manageable activities.
A period of about 20 years was considered because the area started experiencing climate change problems in 1990s after the invasion of Bunya forest reserve in south East Busoga by the people who begun cultivating that land. The cultivation accelerated the climate abnormalities when the people cut down trees and cultivated the wetlands for crop growing. So for more than a decade, the area has experienced this problem of environmental change impacts on the wetlands. Since that time minimal efforts have been taken by the government due to less research conducted in this region to bring up all the detailed problems of the situation.
The study is important because it provides the relationship between the human activities and their contribution to the wetland degradation. It also shows the role of prolonged dry seasons on the water potential in the wetland ecosystem and the surrounding area in Mayuge Town council, Mayuge District. This can act as an assessment and a guide on which the Environment Offices can base on to draft solutions that can control wetland encroachment by the people and also advocating for piped water in the Town council of Mayuge Town.
It also clearly shows the major causes and major forms of wetland degradation and these by looking at them can be reduced. This work has also provided backed up information about the wetland for example the direction of water flow, villages that are adjacent and those surrounding this wetland. This information will be useful in planning foe wetland management to save it from total demise.
The research is of importance to all the academicians and those who will conduct further research in this area. Description of the feasible climate change impacts will be analyzed and this will create awareness and call up on the attention of the environmental bodies to intervene and combine efforts so as to check on this increasing threat.
It is also to create interest to all readers and mostly environmental agencies and researchers since it will be provide detailed indicators of climate change impacts and land degradation on water potential of wetlands. This will provoke environmentalists to undertake more research about the increasing theme of climate change impacts on other ecosystems such as forests, lakes and others.
The research has also provided an insight of additional remedies of reducing hydrological impacts on wetland ecosystems in Uganda.
Environmental change refers to the dynamic systems of energy and material transfer that operate on the global scale to bring about gradual and sometimes catastrophic transformations of the atmosphere, hydrosphere, lithosphere and biosphere (Mannion1991, page 1). Mannion (1991) observed the elements of environmental change being wind, water, plants, and animals. Humans are the most actors through deliberate actions such as deforestation and direct actions such as agriculture, industry and urban development.
UN-HABITAT (2011) defines Climate change as the change in a state of climate that can be identified both basing on physical signs and using statistical tests by changes in the mean and on the variability of its properties and that persists for an extended periods. Therefore the persistent increase in the length of the normal intervals of climate variance can best describe climate change.
Morgan (1986) described land degradation as the deterioration of soil productivity majorly caused by both human activities such as poor waste disposal and poor agriculture methods and Natural processes mostly soil erosion that create rills, Galleys, silting, making the soil with in there un productive for agriculture.
According to the Ramsar International Wetland Conservation Treaty article 1.1, a wetland is defined as an area of marsh, fen, peat land or water whether natural or artificial, permanent or temporary with water that is static of flowing, fresh, blackish or salty including areas of marine water depth of which t low tide does not exceed six meters. A wetland may be a transitional area sandwiched between land and water having hydric soils and hydrophytes vegetation.
Water potential refers to the amount of water available, its movement through and from the wetland, the hydro-periods and water storage in the wetland. However this may change basing on the Season of the year if it is a temporary wetland. For example in case of prolonged dry spells, the amount of water in the wetland may tend to reduce due to increased evaporation resulting from the intensive sun heat.
Harvey (2000) showed that, the earth’s climate has changed throughout the earth’s geological history spanning more than three billion years ago. Past variations in the earth’s climate and in the composition of the atmosphere provide a long term perspective, against which the human induced changes in the atmosphere and in climate can be compared.
(a) Prolonged dry seasons
According to Erwin (2009), Hulme (2005) observed that Climate change is recognized as a major cause of the species and integrity of ecosystems in wetland worldwide. The literature on the ecological and hydrological impacts expected to result from environmental change has grown considerably over the past decade. Barrow (2003) observed that Pressures on wetlands by the people in the region has been due to the direct and indirect effects of prolonged dry seasons over time causing food shortages. Nancy (1998) clearly observed that due to prolonging dry seasons, people tend to cultivate wetlands for activities like crop growing such as rice growing, coco yam growing and other crops. Balek (1977) showed that the impacts resulting from projected changes in extreme climate events in the region include change in base flows, altered hydrology (depth and hydro period), increased heat stress in wildlife, extended range and activity of some pest and disease vectors increased and flooding.
(b) Soil erosion
There is also increased soil erosion due to runoff resulting in a decrease in recharge of some floodplain aquifers. Scarcity of water, increased risk of fires for example thickets around the wetlands, and damage to buildings and infrastructure for example those adjacent wetland shores in case of heavy and intensive rainfall that may cause floods. The world also experiences increased damage to coastal ecosystems such as mangroves and increased tropical cyclone activity (Carla 1995). Under currently predicted future climate scenarios Root et al (2003) observed that climate change can be expected to act in conjunction with a range of other pressures depending on the region.
(c) Rainfall shortages
Bush (2000) said that, prolonged dry spells will cause the drying of water bodies due to rainfall shortages. Water sources such as lakes, ponds, streams and wetlands will dry away (Barrow 2003: Page 137). This is because water places most especially wetland systems are vulnerable and particularly susceptible to changes in quantity and quality of water supply. It appears that climate change may have its most pronounced effect on wetlands through alterations in hydro periods and severity of extreme events in the region. However, other variables related to climate may play important roles in determining regional and local impacts, including increased temperature and altered evapo-transpiration, altered biogeochemistry, altered amounts and patterns of suspended sediment loadings, fire, oxidation of organic sediments and the physical effects of wave energy.
(d) Decline in soil productivity
Increasing decline in the soil productivity has resulted into risks of famine and scarcity of food in the area. This has also occurred due to climate change impacts especially prolonged dry seasons that have consequently caused poor crop yield thus food insecurity.
(e) Parasites and disease outbreak
McMichael et al (1996) further explained that climate change impacts in an area especially subtropical and equatorial regions may include diseases that pose a threat to man, live stock and crops such as malaria due to the stagnant water that give room for mosquitoes to breed, typhoid caused by Salmonella spread through taking contaminated water and bad air, cholera caused by bad food and water, diphtheria, influenza, yellow fever, dengue, foot and mouth disease and rinderpest. Increase in the temperatures from the normal also causes high spread of such diseases (Barrow 2003).
According to the National Land Use Policy (2007), the total area of Uganda is about 241,500km2 and the total area of swamps is about 194,000km2.The causes of wetland degradation exist in two major categories that is to say; human cause and natural cause of wetland degradation (Carla 1995).
Human activities and land use practices have led to wetland degradation which has consequently affected the water availability in the wetland ecosystem (Nancy 1998 and Barrow 2003). The frequent or prolonged presence of water at or near the soil surface is the dominant factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface. Wetlands can be identified by the presence of those plants (hydrophytes) that are adapted to life in the soils that form under flooded or saturated conditions (hydric soils) characteristic of all wetlands (Mitsch and Gosselink 1993). Thus declining water availability of wetland can change the soil chemistry and the plant and animal community. Variation in climate may reduce or increase the natural amount of water entering a wetland or the period of saturation and inundation can, in time, cause the ecosystem to change to an upland system or, conversely, to a riverine or lacustrine system. This alteration can be natural, such as through the successional process of stream impoundment by beavers or climate change. Wetland loss and degradation through disturbing its water flow and storage by man has occurred historically through actions such as: dredging, stream channelization, ditching, levees, and deposition of fill material, stream diversion, ground water withdrawal, and impoundment. Below are the activities man has done to degrade most of the wetlands;
(a) Settlement and urbanization
According to (USEPA 1994b), Urbanization is another cause of impairment of wetlands. Urbanization can result in direct loss of wetland as well as degradation of wetlands. Degradation is due to changes in water quantity, quality and flow rates; increase in pollutant inputs; and reduction in species composition as a result of introduction of non-native species and disturbance. The major pollutants associated with urbanization are sediment, nutrients, oxygen-demanding substances, road salts, heavy metals, hydrocarbons, bacteria, and viruses. These pollutants may enter wetlands from point sources or from nonpoint sources. Construction activities are a major source of suspended sediments that enter wetlands through urban runoff. Impervious surfaces such as roads, buildings, and parking lots are constructed, the amount of impervious surface increases. Impervious surfaces prevent rainfall from percolating into the soil. Rainfall and snowmelt carry sediments; organic matter; pet wastes; pesticides and fertilizers from lawns, gardens, and golf courses; heavy metals; hydrocarbons; road salts; and debris into urban streams and wetlands (USEPA 1993a). Increased salinity, turbidity, and toxicity and decreased dissolved oxygen, all affect aquatic life.
(b) Construction of impervious surfaces
The excessive inputs of nutrients can result into the release of pollutants from a wetland into adjacent water resources (USEPA 1993a). As runoff moves over warmed impervious surfaces, the water temperature rises and dissolved oxygen content of the runoff water decreases (USEPA 1993c). Increased water temperature, as well as the lower dissolved oxygen levels, can cause stress or mortality of aquatic organisms. Rising water temperatures can trigger a release of nutrients from wetland sediment. For example, as temperature rises, sediments release phosphorus at an exponential rate. Thus water temperature increases can lead to eutrophication (release of pollutants from a wetland in adjacent water sources). Impervious surfaces decrease ground water recharges within a watershed and can reduce water flow into wetlands (USEPA 1993c). Significant increases in storm water peak flow rates, and longer-term changes in wetland water availability, as a result of storm water discharge, can cause erosion and channelization in wetlands, as well as alteration of species composition and decreased pollutant removal efficiency (USEPA 1993a; USEPA 1993c). Changes in frequency, duration, and timing of the wetland hydro period may adversely affect spawning (fish breeding), migration, species composition, and thus the food web in a wetland as well as in associated ecosystems (USEPA 1993c).
(c) Waste sites and treatment plants
Wastewater sites and storm water ; Wastewater treatment plant effluent and urban storm water are a source of pollutants that continue to degrade wetlands (USEPA 1994b). The "aging" of wetlands can occur when wetlands filter organic matter. "Aging" is the saturation of the ecosystem by nutrients and heavy metals over time that results in the reduced effectiveness and degradation of the wetland (Mitsch and Gosselink 1986). Wastewater and storm water can alter the ecology of a wetland ecosystem if high nutrient levels lead to extended eutrophication and metals cause plant and aquatic organism toxicity (Ewel 1990). Iron and magnesium, in particular, may reach toxic concentrations, immobilize available phosphorous, and coat roots with iron oxide, preventing nutrient uptake. Over one-third of shellfish waters cannot be harvested because of habitat degradation, pollutants, algal blooms, and pathogens. To a large extent, this degradation is caused by urban pollution (NOAA 1995b; NOAA 1990b; USEPA 1994b).
(d) Heavy metals
These may accumulate in estuarine wetlands, causing deformities, cancers, and death in aquatic animals and their terrestrial predators. Heavy metal ingestion by benthic organisms (including many shellfish) in estuarine wetlands occurs because the metals bind to the sediments or the suspended solids that such organisms feed on or settle on the substrate where such organisms live. Urban and industrial storm water, sludge, and wastewater treatment plant effluent, rich in nitrogen and phosphorus, can lead to algal blooms in estuaries. Algal blooms deplete dissolved oxygen, leading to mortality of benthic organisms since some algae are toxic to aquatic life (Kennish 1992). Excess algae can shade underwater grasses preventing photosynthesis and resulting in sea grass death (USEPA 1994b). Because sea grass meadows reduce turbidity by stabilizing sediments and provide critical food, refuge, and habitat for a variety of organisms, including many commercially harvested fish, the death of these plants profoundly impairs the estuarine ecosystem (USEPA 1994 b).
(e) Construction of roads
Roads that are frequently constructed across wetlands also cause wetland degradation. It is often considered to be more cost effective to build roads or bridges across wetlands than around them since wetlands have low land value. Roads can impound a wetland, even if culverts are used. Such inadvertent impoundment and hydrologic alteration can change the functions of the wetland more especially water storage. Road and bridge construction activities can increase sediment loading to wetlands (Mitsch and Gosselink 1993). Roads can also disrupt habitat continuity, driving out more sensitive, interior species, and providing habitat for hardier opportunistic edge and non-native species. Roads can impede movement of certain species or result in increased mortality for animals crossing them (Zentner 1994). Borrow pits (used to provide fill for road construction) that are adjacent to wetlands can degrade water purity through sedimentation and increase turbidity in the wetland (Irwin 1994). The maintenance and use of roads contribute many chemicals into the surrounding wetlands. Rock salt used for deicing roads can damage or kill vegetation and aquatic life.
(f) Brick making
According the 21st Century Schoolhouse (1997), Brick making is one of the most serious threats to wetlands in Uganda today. This leaves behind big holes, which greatly hinder movement and communication. It is also associated with the clearing of vegetation around the wetlands so as to provide fuel with which to make them (Nancy 1998). Fires that are both natural and those started by man destroy the fertility of the wetlands. The fertility that had accumulated over the years in the soil is lost during the burning of the existing vegetation. These fires are caused by prolonged drought or clearing land for human activity.
As observed by Kennish (1992) industrialization in an area causes wetland degradation. These include; reduction of wetland acreage, alteration of wetland hydro periods and water availability due to industrial water intake and discharge, water temperature increases, point and nonpoint source pollutant inputs, pH changes as a result of discharges, and atmospheric deposition (Carla 1995). Saline water discharges, hydrocarbon contamination, and radionuclide accumulation from oil and gas production can significantly degrade wetlands (Rayle and Mulino 1992). Oil can alter reproduction, growth and behavior of wetland organisms, and can result in mortality. Plants suffocate when oil blocks their stomata (Dibner 1978). Polynuclear aromatic hydrocarbons (PAHs) are extremely toxic compounds that can enter estuarine wetlands through industrial effluent and atmospheric deposition. PAHs concentrate in sediments and thus contaminate benthic organisms (Kennish 1992). Fish contaminated with PAHs exhibit external abnormalities, such as fin loss and dermal lesions. Waste sites adjacent the wet lands release Toxic radioactive or acidic compounds and high concentrations of metals in abandoned industrial wastes may be an ecological risk to wetlands fauna and flora. Many sites are close enough to directly or indirectly (through water flow) impact wetlands (Magistro and Lee 1988). Clean-up activities at Superfund and RCRA sites can degrade adjacent wetlands as well through disturbance of hydrology, introduction of contaminants, and degradation of habitat by equipment.
(h) Metals and radio nuclides
These tend to naturally concentrate in wetlands sediments and peat (Nancy 1998). Such concentrations can be released in a flush from the wetland into surface water or ground water as a result of pollutant inflow or hydrologic alteration of the wetland (Owen 1992). Such a release of toxic compounds could generate serious environmental consequences. Intake of very low concentrations of radio nuclides, such as uranium, from a water supply, for instance, will cause kidney failure and death. If radioactive peat or peat with a high metal concentration is used for gardening or agricultural activities, it can pose a human health risk as well (Owen 1992).
The practice of agriculture in wetlands also causes wetland degradation (Carla 1995). Historically, agriculture has been the major factor in freshwater and estuarine wetland loss and degradation. Due to fact that the wetlands have fertile soils many people have been attracted to carry out agriculture. Crops such as yams, sugarcane, maize and sweet potatoes do well in wetlands (Nancy 1998). This results in over-cultivation of the wetlands due to desire for high yields, hence high rate of their depletion. The increased desire for utilization of the natural resources in the wetlands such as the aquatic life, water for domestic use, hunting and many others lead to increased population growth around the wetlands although the passage of the Food Security Act of 1985 "Swamp buster" provision prevented the conversion of wetlands to agricultural production. Certain exempted activities performed in wetlands can degrade wetlands such as harvesting food, fiber, or forest products, minor drainage, maintenance of drainage ditches, construction and maintenance of irrigation ditches, construction and maintenance of farm or forest roads; maintenance of dams, dikes, and levees. Direct and aerial application of damaging pesticides (herbicides, fungicides, insecticides, fumigants), and ground water withdrawals, Grazing livestock can degrade wetlands. Urea and manure can result in high nutrient inputs. Cattle traffic may cause dens and tunnels to collapse.
(j) Animal grazing
Animal grazing of riparian areas by livestock reduces streamside vegetation, preventing runoff filtration, increasing stream temperatures, and eliminating food and cover for fish and wildlife. As vegetation is reduced, stream banks can be destroyed by sloughing and erosion. Stream bank destabilization and erosion then cause downstream sedimentation (Kent 1994b). Sedimentation reduces stream and lake capacity, resulting in decreased water supply, irrigation water, flood control, hydropower production, water quality, and impairment of aquatic life and wetland habitat (Balek 1977).
(k)Mining of sand and peat
These are mined for various uses such as agricultural and horticultural uses on a relatively small scale in the United States (Mitsch and Gosselink 1993). Wetlands that are mined for peat are significantly modified, often being transformed into open water habitat (Camp Dresser and McKee 1981). Peat mining not only removes peat but requires clearing of vegetation, drainage of the wetland, and creation of roads for equipment access to harvest the peat. These activities destroy the portion of the wetland selected for harvest and degrade adjacent areas. These activities can alter a wetland's hydrology, water quality, and species composition. Excessive amounts of fertilizers and animal waste reaching wetlands in runoff from agricultural operations, including confined animal facilities, can cause eutrophication (Nancy 1998).
(a) Soil erosion
Erosional processes cause wetland degradation and alter the water potential of the wetland (Richardson et al. 1994). Thus, wetland sediment inputs are derived primarily from wind and water erosion of upland soils in catchment and adjacent areas. Tillage has greatly altered the surface hydrologic dynamics of wetland catchments; conventional tillage increases erosion rates and surface runoff relative to grassland landscapes (Gleason 1996 and Mushet 1996). However, few studies have examined the impact of sedimentation on the majority of functions that prairie wetlands are known to perform. Martin and Hartman (1987) found that the flux of inorganic sediments into wetlands with cultivated catchments occurred at nearly twice the rate of wetlands with native grassland catchments. Organic matter also occurs at significantly greater concentrations in wetland sediments in wetlands with native grassland catchments than in wetlands with cultivated catchments. Dieter (1991) shows that turbidity was highest in tilled than in untilled and partially tilled) wetlands. Similarly, Gleason (1996) and Gleason and Euliss (1996) found that sedimentation rates and the inorganic fraction of sediment entering wetlands were significantly higher in wetlands with cultivated catchments than in wetlands with grassland catchments (Morgan 1986).While natural processes may fill wetlands with sediment, anthropogenic influences have great potential to accelerate erosion, prematurely fill wetlands, and degrade wetland functions. The most severe impact occurs when wetlands fill with so much sediment that they no longer pond water; such wetland have lost their capacity to perform most natural wetland functions. While the loss of wetland functions when basins totally fill with sediment is intuitive, the relationship of functional loss and degradation to gradual but chronic filling is less well appreciated and understood. In the following discussion, the impacts of sedimentation on primary production, aquatic invertebrates, wildlife habitat, and on hydrologic and water quality issues shall be examined (Nancy 1998 and US geographical Survey).
(b) Climate change
The impacts of climate change also cause wetland degradation thus a reduction in the available water of individual wetland ecosystems mostly through changes in precipitation and temperature regimes with great global variability Erwin (2009). Wetland managers face a new set of challenges when addressing the impacts from global climate change (Wetlands Ecol Manage 2009). Long dry seasons can dry up wetlands (Bush 2000). Floods, droughts and other extreme weather events will alter water flows, leading to more polluted runoff and lower water purity in the wetlands (Balek 1977).
Wetland degradation is a danger to these ecosystems in an area. Careless agricultural practices, pollution and deforestation cause severe soil erosion on the flanking hills of the wetland. Several types of wetland degradation exist as they are a threat to aquatic plants and animals. The usual types of swamp degradation that exist are (physical or mechanical degradation, chemical and biological degradation).
(a) Physical degradation
This involves wetland flow crusting, sealing and reshaping of the flanking hills of the wetland due to severe erosion and other factors like compaction due to trampling by grazing animals in the wetland. Soil crusting and compaction tend to increase runoffalong the flanking hills of the wetland. This consequently decreases the infiltration of water into the soil reducing on the return flows in the wetland. Vegetation destruction and change in the wetland systems from the normal are all physical Deterioration (Adapted from FAO/AGL 2000).
(b) Chemical Deterioration
This involves loss of the chemical elements of the wetland that are so important in the ecosystem which may consequently lead to the demise of fauna and flora , Stalinization, acidification, soil pollution, and fertility decline. The sedimentation of the wetlands reduces the capacity of wetlands to hold water. In case of high evaporation than precipitation problems can arise due to accumulation of salts, which impedes the entry of water in plant roots. Wetland toxicity can be brought about in a number of ways. Typical examples are from municipal or industrial wastes, oil spills, the excessive use of fertilizer , herbicides and insecticides by the farms upland, or the release of radioactive materials and acidification by airborne pollutants (Land and Plant Nutrition Management Service, 2002).
Freshwater ecosystems provide a wide range of goods and services. Wetlands exhibit extensive biodiversity, function as filters for pollutants, and are important for carbon sequestration and emissions. Rivers transport water and nutrients from the land to the oceans and provide crucial buffering capacity during droughts especially if fed by mountain springs and glaciers. Lakes serve as sediment and carbon sinks and provide crucial repositories of information on past climate changes (USGRP, 2009). But due to climate change impacts, wetland water resources are exposed to the following consequences:-
(a) Water scarcity
The scarcity of water is expected to become an ever-increasing problem in the future, for various reasons. First, the distribution of precipitation in space and time is very uneven, leading to tremendous temporal variability in water resources worldwide (Oki et al, 2006) and (Vorosmarty2000). Secondly, the rate of evaporation varies a great deal, depending on temperature and relative humidity, which impacts the amount of water available to replenish groundwater supplies. The combination of shorter duration but more intense rainfall (meaning more runoff and less infiltration) combined with increased evapotranspiration (the sum of evaporation and plant transpiration from the earth's land surface to atmosphere) and increased irrigation is expected to lead to groundwater depletion (Konikow and Kendy 2005). Water purity; Freshwater bodies have a limited capacity to process the pollution stemming from expanding urban, industrial and agricultural uses, Water quality degradation can be a major source of water scarcity. Although the IPCC projects that an increase in average temperatures of several degrees as a result of climate change will lead to an increase in average global precipitation over the course of the 21st century, this amount does not necessarily relate to an increase in the amount of potable water available.
(b) Decline in water purity
While the water will carry higher levels of nutrients, it will also contain more pathogens and pollutants precipitation and runoff. These contaminants were originally stored in the groundwater reserves but the increase in precipitation will flush them out in the discharged water (IPCC 2007).
Similarly, when drought conditions persist and groundwater reserves are depleted, the residual water that remains is often of inferior quality. This is a result of the leakage of saline or contaminated water from the land surface, the confining layers, or the adjacent water bodies that have highly concentrated quantities of contaminants. This occurs because decreased precipitation and runoff results in a concentration of pollution in the water, which leads to an increased load of microbes in waterways and drinking-water reservoirs (IPCC 2007).
(c) Increase in water temperature
Due to prolonged dry seasons, water tends to heat up causing high temperatures that result into water degradation (Barrow 2003, Page 137,139). The increase in water temperatures has led to a bloom in microbial populations, which have had a negative impact on human health. In addition, the rise in water temperature has adversely affected different inhabitants of the ecosystem due to a species' sensitivity to temperature. The health of water bodies, such as wetland, is dependent upon its ability to effectively self-purify through biodegradation, which is hindered when there is a reduced amount of dissolved oxygen. This occur when water warms and its ability to hold oxygen decreases. Consequently, when precipitation events do occur, the contaminants are flushed into waterways and drinking reservoirs, leading to significant health implications (IPCC 2007).
(d) Drying away of wetland reservoirs
Climate change threatens the stability of mires (wet, swampy ground; bog; marsh) by increasing decomposition rates due to higher temperatures and lowering of water tables (Bush 2000). Reduction of the carbon store, increased flux of CO2 and possibly of CH4, contribute to further amplification of greenhouse gas production. Disruption of intact mire surfaces also increases the generation of ‘colored water’, with potential effects on aquatic ecology, the breeding cycles of important fish species, and flood control (The Netherlands Institute of Ecology 2010).
The research study was conducted in Uganda in areas of Mayuge District in the Mayuge town council with in and around Bugingo Wetland system. Geographically, Mayuge District is located in the South-Eastern Uganda in Busoga region on the Northern Shoreline of Lake Victoria bordered by Tanzania in the south, Iganga in the North, Jinja in the West and Bugiri districts in the East. The district covers a total area of approximately 4640sqkm having water on the largest area of about 3550sqkm and population of about 441,700 people according to the District Summary sheet 2002 (Population and projection). Mayuge Town council covers an area of approximately 31.91Km2 with 16 villages and 4 parishes according to the District Parish Summary Sheet 2002 (Population and projection) Report, with a total population of 6,945 people. Bugingo wetland runs across three parishes Kavule covering villages like Budhebera, D.F.I., Ikulwe parish covering villages of Katwe, Igamba, Tsetse zone, Bugingo and Wakalende in Kyebando Parish. The wetland crosses Bugadde-Mayuge road and continues to the South East which finally joins up with the Hannington Bay on Lake Victoria, South of Mayuge Town (USD Ikulwe sheet 72/2 edition 1.U.S.D Series Y732). This wetland system lies within the geographical coordinates of33025’E to33030’E of the Prime Meridian and between 0025’N to 0030’N of Equator according to U.S.D Ikulwe sheet (Topographic map) 72/2, Series Y732, edition 1.U.S.D, published by the department of Lands and Surveys, Uganda 1963 and Kyemeire Sheet 73/1, Series Y732.
The research was conducted in Bugingo wetland system and the main issue of concern was the effects of environmental change on the water availability in Bugingo wetland which caused water scarcity in Mayuge town council and the possible solutions. During the research, a descriptive and analytical research was adopted. This is because the study shall be based on the existing facts and such facts shall be used analytically using simple statistical methods. This type of research shall be used because the impacts of climate change can be seen and are not short term, this therefore needs using the existing facts about the problem to conduct further research and build on that information to make critical analysis hence better findings during the research. Therefore most of the findings will be qualitative.
The area has got drainage features majorly swamps like Bugingo, Wakalende and many others. Mayuge District is relatively flat with isolated ridges and hills with interfluves undulating low lands and pediments. The lowest point is below 1000m above sea level in the south along the lake and highest about 1400m above sea level found in the North. The district has long a shore line of Lake Victoria with swamps and wetlands are along that shore line. 7,660.4 square kilometres (2,957.7 sq mi) of the district surface area is open water of Lake Victoria. It is estimated that this represents 77% of the total surface area in the district. Another 10% of the district is protected national forest reserve. Mayuge town council has hills such as Mayuge hill of about 1,185m above sea level and Katwe hill of about 1,185m .there is also low lying areas in forms of Valleys such as Bugingo valley in the South of Mayuge town Hill.
The area experiences tropical equatorial climate characterised by daily sun shine and it receives an average rainfall of about 1,500mm per annum. Mayuge experiences two dry seasons and two wet seasons. The first dry season starts from December to early February and then early July to August. These dry seasons are the periods for harvesting crops since the area’s inhabitants are crop cultivators. The wet seasons are experienced in mid March to May and then from August to late September. These wet seasons are periods of planting crops. But the dry seasons are increasingly extending from the normal length due to the change in the climate of the area.The area originally experienced the first dry season stretching from December to early February during the past decades, but in the mid 1980s, the dry spells changed from early February to late March as per the old respondents of the area, and then from late June to Mid August. The area has tropical equatorial vegetations as the green cover.
MAP 1: SHOWING THE LOCATION, PHYSICAL AND MAN MADE FEATURES IN BUGINGO WETLAND, MAYUGE TOWN CONCIL MAYUGE DISTRICT
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Source: Kyemeire Sheet 73/1, Series Y732 and U.S.D Ikulwe sheet (Topographic map) 72/2, Series Y732, edition 1.U.S.D, 1963 by Ug. Local Adm.
The soils are brownish on the uplands and continue to become dark to the valley of the wetland. It has fine particles. The soils are fertile loamy and of high productivity. And due to intensive sun shine and prolonged drought in the area, the productivity is highly affected due to less moisture which leads to low crop yields. This consequently causes food scarcity.
Non-probability sampling was used during the research. This involved selection of participants because they were available, convenient, or represent some characteristic the investigator wants to study. In this way L. C. 1 chair persons of the selected villages were sampled with other significant citizens. The following procedure was used when obtaining samples;
illustration not visible in this excerpt
Categorical/selective sampling was also used, where a given population was selected. The targeted population was the people living in he selected villages that surround the wetland and the district environmental personnel of Mayuge district such as the environmental officer, town council officials concerned with water distribution and other agencies of environmental conservation.
The targeted people were those living within and around the wetland system of Bugingo in Mayuge Town Council. According to the District Summary Sheet 2002, (Population and projection), Mayuge town council has a total population of approximately 6,945 people and above, having 2,043 being male, about 2,640 are female and the rest are children. The villages around the place are Katwe, Tsetse, Bugingo in Ikulwe parish, D.F.I and Budhebera in Kavule parish in Mayuge town council. Here I chose two parishes as my sample places. The adults who are both men and women were mostly considered for sampling. Here a sample size of 25 people was selected taking five people from each village including the L.C.1 chairpersons.
Primary data was that information collected by use of first hand methods of data collection. This data was often authentic, reliable and its validity are always greater than the secondary data.
Using a topographic map of Ikulwe sheet (Mayuge) 72/2, seriesY732, the area of study was demarcated. The demarcated area included Bugingo wetland system as well as its catchment zone. This area of the wetland was between the points of coordinates 0033’3086”N and 33038’1788”E (Near Rena College Mayuge), 33028’411”E and 0027’1134”N (at Bunya S.S), 0036’5314N and 33030’865”E (At Taweed Primary school), and 0.4438N and 33.483E (at the district headquarters). The part of the wetland selected lied between those points. A small section/transect with in this study area was identified. This selected section was more than 200m wide and transcending from one side of the wetland to the other. Another section was selected outside the wetland (on the flanking hills) also for detailed study. This section was of more than 200m wide along the hill flanking the wetland.
Detailed study was administered in these demarcated sections at 200m and 100m. A survey was carried out along the sections made. In the course of these surveys, field observations were made on the climate change impacts, forms of wetland degradation and their causes as well as assessment of climate change impacts on the wetlands
This comprised of a face to face conversation with key informants in the Town council such as the District Environment Officer, the District Health Inspector, the Town council Health Officer and the District Forest Officer. The interviews focused on the broad issues of the implication of climate change and land degradation on the wetland water potential.
This was a list of open-ended or close ended questions. The lists of questions were designed basing on the research questions or areas of interest in this study. The questionnaire was divided into four sections which included; section A: Respondent and Household Characteristics, Section B: climate change impacts in the area, section C: Climate Change Impacts on the water potential on the wetland catchment and Section D: Government Response. A maximum of 25 questionnaires were designed to 25 Household respondents selecting five households from each Village and ten from each Parish.
(d) Focus group
This was in qualitative research in which a group of people were asked about their perceptions, opinions, beliefs, and attitudes towards wetland system. Questions were asked in an interactive group setting since it was a two way open focus group. The participants were free to talk with other group members. The focus group comprised of the people around the wetland of Bugingo in Mayuge Town Council with a total population of approximately 6,945people and also the environment officials on the district level and some other people who are entitled to wetland and water maintenance.
The measurements of volume of gulley erosion were obtained and tabulated (see table 1) along the hill slopes, volume of rill erosion was also measured and tabulated (see table 2). This is because these were important in analyzing the surface erosional impacts on wetland degradation in the area. Other necessary estimations were used during the research for example the water colour used to estimate its quality. Tastes were also conducted on three main water sources to establish the water PH. This was done by use a blue and red litmus paper (see observations in table 3).
Secondary data was obtained from two different research stands that is Quantitative research: Census, housing, social security as well as electoral statistics and other related databases. Qualitative, focus groups transcripts, field notes, observation records and other personal, research-related documents. The benefit of using secondary data is that much of the background work needed has already been carried out, for example: literature reviews, case studies might have been carried out, published texts and statistics could have been already used elsewhere, media promotion and personal contacts have also been utilized. This wealth of background work meant that secondary data generally had a pre-established degree of validity and reliability which needed not be re-examined by the researcher who is re-using such data. Furthermore, secondary data was also helpful in the research design and provided a baseline with which the collected primary data results could be compared to. Therefore, it was always wise to begin this research with a review of the secondary data.
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