Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss cos...Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss costs a profound amount of the national GDP and deters land productivity.Quantifying soil loss and prioritizing areas for conservation is imperative for proper planning and resource management.Therefore,this study aimed at estimating the mean annual soil loss rate of Gilgel Abay watershed which has critical implications on Lake Tana and Abbay River(Upper Blue Nile River),using RUSLE and morphometric analysis methods.Datasets including rainfall,soil,Digital Elevation Model and land use/land cover were used to generate important parameters required for the soil loss estimation.Data collected through field observation,consultation with experts and document analysis were used for validation purposes.The results of the study reveal that the watershed experienced an average soil loss rate of 39.8 t ha^(-1)yr^(-1).Subsequently,nearly 25%(37,038 ha)of the watershed is threatened by moderate to very severe soil loss.Among the four sub watersheds,sub watershed 3(S3)and sub watershed 4(S4),which consist of about 65%(105,000 ha)of the total area of the study watershed,experienced an annual soil loss rate of over 30 t ha^(-1)yr^(-1).The amount of soil loss that the study watershed has experienced is above the soil loss tolerance level of Ethiopia(2-18 t ha^(-1)yr^(-1))and the tropical region(10 t ha^(-1)yr^(-1)).Similarly,the results of morphometric analysis showed that the studied watershed has S-shaped hypsometric curve,an indication for maturity stage of landscape development.The studied watershed is also characterized by a non-circular shaped drainage with rugged and dissected topography that contributes to high flash flood,peak discharge and incidence of soil loss.The result of both models signified that S3 and S4 are highly susceptible to soil erosion.Therefore,these two sub watersheds need priority for soil and water conservation(SWC)measures.Furthermore,the study demonstrated the importance of the integration of different models in the identification of soil erosion prone areas and prioritization for the proper implementation of SWC measures.展开更多
Modeling urban land-use dynamics is critical for urban experts’and infrastructure managers’planning.This study attempts to explore the land-use/land-cover(LULC)dynamics of Gondar using satellite images from 1984 to ...Modeling urban land-use dynamics is critical for urban experts’and infrastructure managers’planning.This study attempts to explore the land-use/land-cover(LULC)dynamics of Gondar using satellite images from 1984 to 2020.Markov-Chain and Cellular Automata(MC-CA)models have been recognized as performing well in predicting urban land-use change.However,only a few models work in Ethiopia in general,and no study in Gondar has applied this approach to study urban land-use patterns.Therefore,Gondar land-use/land cover changes of Gondar were predicted using the MC-CA model in IDRISI.The built-up area in Gondar city covered 1413 ha(3%of the total area)in 1984 and increased to 2380 ha(5%)in 1994;21153 ha(45.5%)in 2004;22622 ha(48.7%)in 2014;and 23427 ha(50.5%)in 2020.The area has been predicted to reach 57.5%in the 2050s,showing a faster increase that will cause a very vast loss of farmland.This will increase urban sprawl challenges as well as overall environmental disequilibrium in the preceding decade.Thus,innovative and careful structures and systems in urban planning are required to secure a sustainable urban future and to make our cities livable and competitive in the paradigm of sustainable cities.展开更多
Land suitability analysis of Moringa oleifera tree cultivation is important to enhance its product,as the demand forthis tree for medicinal values and food sources is increasing worldwide.Therefore,this study aimed to...Land suitability analysis of Moringa oleifera tree cultivation is important to enhance its product,as the demand forthis tree for medicinal values and food sources is increasing worldwide.Therefore,this study aimed to assess suitableland for Moringa oleifera tree cultivation by using the integration of multi-criteria evaluation with geospatialtechnologies in the Dhidhessa catchment,western Ethiopia.Five parameters,namely:slope,land use and landcover(LULC),soil texture,land surface temperature,and rainfall data,were used in this study.The land suitabilityevaluation of Moringa oleifera is classified into three classes as highly suitable,moderately suitable,and notsuitable.The results revealed that,about 344.4 km2(12.2%)of the area is categorized into highly suitable,and2343.7 km2(83%)is moderately suitable for Moringa tree,whereas,137.2 km2(4.9%)is categorized as notsuitable for Moringa oleifera tree cultivation.Hence,based on the finding of the study,we suggested that farmers andother stakeholders can cultivate Moringa oleifera trees in the Dhidhessa catchment.展开更多
The study examines the Spatial Pattern and Distribution of Crime in Suleja LGA, Niger State, Nigeria. The study used GIS and statistical methods to analyse the pattern and distribution of crime incidence in the study ...The study examines the Spatial Pattern and Distribution of Crime in Suleja LGA, Niger State, Nigeria. The study used GIS and statistical methods to analyse the pattern and distribution of crime incidence in the study area. The records of each crime incidence were geocoded. Microsoft Excel was used to collate and organise the crime entries before they were imported into the ArcGIS Pro 2.0 environment. A geodatabase was created where the spatial and aspatial data were encoded and geospatial analysis was performed. The study reveals that the crime distribution pattern is generally clustered with a Global Moran’s I index of 0.097, a Z-score of 1.87, and a P-value < 0.06. Furthermore, the study reveals that armed robbery (61), kidnapping (40), car theft (33), culpable homicide (31), rape (29), and robbery (13) cases rank the highest in crime rate. Equally, findings of the study show that Chaza, Kwamba, Madalla, Suleja central, and Gaboda are the major crime hotspot zones at 90% confidence, as analysed using the Getis-Ord Gi* (Hot spot analysis) spatial statistics tool in ArcGIS Pro 2.0. The research therefore recommends that more effort be put into fighting crime, especially in areas where there are low-security formations, as they mostly have the highest record of crimes committed. Also, the patrol units should be equipped with GPS for better surveillance and real-time tracking of criminal activities.展开更多
Temperature and water flow through a culvert beneath the Alaska Highway near Beaver Creek,Yukon,were measured at hourly intervals between June and October 2013.These data were used to simulate the effect of the culver...Temperature and water flow through a culvert beneath the Alaska Highway near Beaver Creek,Yukon,were measured at hourly intervals between June and October 2013.These data were used to simulate the effect of the culvert on the thermal regime of the road embankment and subjacent permafrost.A 2-D thermal model of the embankment and permafrost was developed with TEMP/W and calibrated using field observations.Empirical relations were obtained between water temperatures at the entrance to the culvert,flow into the culvert,and water temperatures inside the structure.Water temperatures at the entrance and inside the culvert had a linear relation,while water temperatures inside the culvert and water flow were associated by a logarithmic relation.A multiple linear regression was used to summarize these relations.From this relationship,changes in the flow rate and water temperatures at the entrance of the culvert were simulated to obtain predicted water temperatures in the culvert.The temperatures in the culvert were used in the thermal model to determine their effects on the ground thermal regime near the culvert.Variation of ±10% in water flow rate had no impact on the thermal regime underneath the culvert.Variation of water temperature at the entrance of the culvert had a noticeable influence on the thermal regime.A final simulation was conducted without insulation beneath the culvert.The thaw depth was 30 cm with insulation,and 120 cm without insulation,illustrating the importance of insulation to the ground thermal regime.展开更多
This study was aimed at examining land cover changes for the last 35 years and its causative factors in Gilgel Abbay watershed by using GIS and remote sensing, survey and population data. The land use and cover change...This study was aimed at examining land cover changes for the last 35 years and its causative factors in Gilgel Abbay watershed by using GIS and remote sensing, survey and population data. The land use and cover changes study will help to apply the appropriate land use. The land cover/use status for the years 1973, 1986, 1995 and 2008 were examined using land sat images. The changes in different land cover units such as forest, wood and bush lands, grass, wetlands and water bodies, and farm and settlements were analyzed. Population change, tenure, poverty and lack of market and credit facilities in the watershed area were analyzed as causes of land cover changes. The results of the study have shown that during the last 35 years forest, grass lands, wetlands and lake areas were converted to farm and settlement areas. There was rapid increase of population with growth rates of 4.9% and 3.5% (1984-1994 and 1994-2007), respectively per annum which caused more land cover changes.展开更多
Livelihood assets are a matter of high concern for secured survival.Drought-prone Gamo lowland households have differential access to livelihood resources which indicates the varying capacity of resisting to shocks.Th...Livelihood assets are a matter of high concern for secured survival.Drought-prone Gamo lowland households have differential access to livelihood resources which indicates the varying capacity of resisting to shocks.The main objective of this study is to explore the impacts of livelihood assets on livelihood security in the drought-prone Gamo lowlands.Multistage sampling procedures were employed to select the study sites and sample respondents.Primary data of households’capital assets and livelihood security status were produced from 285 survey households,agricultural experts,key informants,focus group discussants,and field observation through transect walks.Descriptive and inferential statistics were used to analyze quantitative data,whereas discussions and annotations were employed for analyzing qualitative data.The Sustainable Livelihoods Framework is used with modifications to schematize the study conceptually.The findings indicated that the study households possessed combinations of livelihood resources differentially.Financial and natural capitals were found to be the most deficient and better-accessed capitals,respectively.The study also showed that lowland residents’access to assets has significant indications of livelihood security.Households’poor access to assets such as financial,information,and social capital demands raised attention of the concerned stakeholders and policy debates in the drought-prone rural setup.Hence,it has been concluded that the more assets are accessed,the stronger the capacity of the households to resist shocks,and better the livelihood security.Accordingly,enhancing people’s access to multiple livelihood assets is suggested to sustainably secure livelihoods.展开更多
Previous studies in Delo-Mena district failed to provide conceptual framework about causes and impacts of deforestation including prediction of spatial location of future deforestation. The study was aimed at investig...Previous studies in Delo-Mena district failed to provide conceptual framework about causes and impacts of deforestation including prediction of spatial location of future deforestation. The study was aimed at investigating spatiotemporal dynamics and prediction of future trends of deforestation in this area. Three periods Landsat images were downloaded and preprocessed using ENVI 4.3. Supervised classification technique was employed for image classification. Land Change Modular used to predict deforestation based on transition between 2000 and 2015 along three driving variables (road distance, settlement and soil). Six land-use land-cover classes were classified for three periods. The result indicated that the forest areas were 91,339, 73,274 and 70,481 hectors in year 2000, 2010 and 2015, respectively. This forest area was reduced by 20% between 2000 and 2010 at annual rate of 2%. Between 2010 and 2015, a forest area was lost by 4% with annual rate of 1%. This deforestation rate was greater than global rates and was lower than rates of south eastern African countries. Farmland expansion was a major cause of deforestation contributed to the annual forest loss by 4.9% and 36% over different periods. In 2030, about 33,243 hectors of a forest area would be expected to disappear that implied emission of about 17 million ton of carbon dioxide. Fuelwoods shortage and loss of biodiversity were perceived as impacts of deforestation. Farm-land and settlement were found increasing at expense of vegetation. Forest plantation, supply of fuel efficient technology and community mobilization were recommended that would be emphasized by the forestry sector based at the district office.展开更多
As a hazard, flood is an extremely important indicator of how a city is resilient to waterborne diseases and epidemics. Over many decades, flood as a hazard has been a major factor in inducing displacement of marginal...As a hazard, flood is an extremely important indicator of how a city is resilient to waterborne diseases and epidemics. Over many decades, flood as a hazard has been a major factor in inducing displacement of marginalized section of the people. Austin city within Central Texas has been identified as one of the major hotspots for flooding in recent decades. Thus, the objectives of the paper are two folded: 1) Empirically, we analyzed and mapped out the susceptibility levels from the factors of physical environments to assess the risk of urban flooding (rainfall data, surface water bodies and topography);in Austin, Texas and 2) Methodologically, we created a re-useable ArcGIS scripting tool that can be used by researchers to automate the process of flood risk modelling with certain criteria. The paper showcases a novel time sensitive building of a tool which will enable better visibility of flood within the city of Austin.展开更多
The Clean Development Mechanism,a flexibility mechanism contained in the KyotoProtocol, offers China an important tool to attractinvestment in clean energy technology and processesinto its electricity sector. The Chin...The Clean Development Mechanism,a flexibility mechanism contained in the KyotoProtocol, offers China an important tool to attractinvestment in clean energy technology and processesinto its electricity sector. The Chinese electricitysector places centrally in the country’s economy andenvironment, being a significant contributor to theacid rain and air pollution problems that plague manyof China’s cities and regions, and therefore a focusof many related energy and environmental policies.China’s electricity sector has also been the subjectof a number of economic analyses that have showedthat it contains the highest potential for clean energyinvestment through the Clean DevelopmentMechanism of any economic sector in China. Thismechanism, through the active participation frominvestors in more industrialized countries, can helpalleviate the environmental problems attributable toelectricity generation in China through advancingsuch technology as wind electricity generation, cleancoal technology, high efficient natural gas electricitygeneration, or utilization of coal mine methane. Inthis context, the Clean Development Mechanismalso compliments a range of environmental and energypolicies which are strategizing to encourage thesustainable development of China’s economy.展开更多
Objective-To investigate forest cover change in Masese Local Forest Reserve and its effects on the livelihoods of the dependent communities;to establish the occurrence of forest cover change in Masese Local Forest Res...Objective-To investigate forest cover change in Masese Local Forest Reserve and its effects on the livelihoods of the dependent communities;to establish the occurrence of forest cover change in Masese Local Forest Reserve;to determine the extent of forest cover change in Masese from 1990to 2005;to determine the tree species that have been affected by forest cover change in Masese; and to assess the effects of forest cover change on the livelihoods of the dependent communities. Methods-Interviews and questionnaire were conducted with a proportion of 36households from Maondo and 84households from Mulimambango settlements.Scenes of landsat images of 1990,2000, 2005and Earth Google image for Masese were used for map analysis.Also remote sensing was used to analyze landsat images and Google image to detect forest and non-forest classes.Results and Conclusion-Forest cover change has adverse implication on the provision of wood forest products and nonwood forest products to the dependent local communities.The declining status of dominant Baikiaea Forest that has exploitable species for building materials and fuel wood has affected the livelihoods of the dependent local communities.There is also increased cost and shortage of fire wood and building materials due to deforestation in Masese Forest Reserve.展开更多
A systematic analysis of land use/cover change is so decisive to exactly understand the extent of change and take essential measures to curb down the rate of changes and protect the land cover resources sustainably. T...A systematic analysis of land use/cover change is so decisive to exactly understand the extent of change and take essential measures to curb down the rate of changes and protect the land cover resources sustainably. This land use/land cover change study was conducted in Agarfa district of Bale zone, Oromia Regional State, Southeastern Ethiopia. The objectives of this study were to evaluate the trends, drivers and its socio-economic and environmental implication in study area. A descriptive research method was employed to achieve the intended objectives of the study. In the three years (1976, 1995, and 2014) Landsat Satellite images and socio-economic survey were the main data sources for this study. ERDAS Imagine and Arch-GIS tools were used to classify and generate land use/land cover maps of the study area. Survey questionnaires, key informant interviews, and field observation were employed to obtain information on drivers and its socio-economic and environmental implication in the district. The results show that the land use/land cover of the study area had changed dramatically during the period of 38 years. A rapid loss of forest land and shrub land cover in the landscape took place between 1976 and 2014. Conversely, agriculture and grazing lands were increased by 30% and 42% respectively at the expense of the lost land use/land cover types. Forest land is the most converted cover type during the entire study period. In the 38 years, forest lands diminished by over 65% of the original forest cover that was existed at the base year (1976). Local climate change, declining agricultural productivity and livestock quantity and quality and scarcity of fuel wood and constructional materials were some of the socio-economic and livelihood impacts of land use and land cover change of the study area. Thus, this finding affords information to land users and policy makers on extent of the change and social forces leading to this changes and its subsequent implication on local socio-economic and environmental conditions of the study area.展开更多
The study attempted to understand indigenous small farming systems and its challenges with the framework of agricultural modernisation in Konso community, Southern Ethiopia. There were 400 household heads from differe...The study attempted to understand indigenous small farming systems and its challenges with the framework of agricultural modernisation in Konso community, Southern Ethiopia. There were 400 household heads from different wealth rank and farming practices considered for in-depth interview. This was completed by focus group discussions and plot level investigations. The findings indicated that the community and landscape are characterized by heterogeneity, implying the challenges of introducing standard modern agricultural technologies. Moreover, the community has wide range of indigenous soil and water conservation (SWC) measures geared to production and protection. For example, in a single plot with a size of less than 0.4 ha, it was possible to produce up to 35 plant spices with multiple functions. The evaluation of the modern agricultural extension services by the community indicates that about 17% was found to be positive in line to diffusion of new technologies and rehabilitation of degraded lands. However, the strengths seem to be offset by the weaknesses (61%) with respect to food security, resilience to drought, synergy with indigenous knowledge, empowerment in decision-making, The findings underlined that to assure food security and sustainable resource management, creating policy environment for holistic and integrated approach, supporting indigenous practices and empowering community in decision making are fundamental.展开更多
This study was conducted in Melka Wakena catchment;south eastern Ethiopia to assess land use/cover change (LULCC) and topographic elevation effect on selected soil quality/fertility parameters. 144 soil samples collec...This study was conducted in Melka Wakena catchment;south eastern Ethiopia to assess land use/cover change (LULCC) and topographic elevation effect on selected soil quality/fertility parameters. 144 soil samples collected from 0 - 30 cm depth under three land cover types across three elevation gradients were analysed for selected soil quality/fertility parameters. Data were statistically analyzed using analysis of variance (ANOVA) and mean comparisons were made using Least Significant Difference (LSD). The soil properties examined generally showed significant variations with respect to land-use/land cover changes and elevation. Soil particles, soil organic carbon, total N, pH, available phosphorus, potassium and calcium content significantly decreased as forestland is converted into cropland/grassland. Heaviest soil deterioration was recorded in soils under cropland and followed by grassland soils. The conversion of natural forest to different land uses without proper soil conservation and management practices resulted in the overall decline of soil fertility quality. Thus, integrated land resource management approach is indispensable for sustaining agricultural productivity and the environmental health of the Melka Waken a catchment.展开更多
Prospects and challenges of Village Lands Forest Reserves (VLFRs) in Mbarali district, southern Tanzania were investigated. Data were collected through questionnaire surveys, in-depth key informant interviews, physica...Prospects and challenges of Village Lands Forest Reserves (VLFRs) in Mbarali district, southern Tanzania were investigated. Data were collected through questionnaire surveys, in-depth key informant interviews, physical field visits and documentary reviews. A total of 44 subjects were involved in the study. SPSS, Microsoft Excel and content analysis were used in data analysis. Findings indicated that inadequate capacity building, passive community participation and involvement in VLFRs management fostered the continued forest degradation and deforestation in the study area. It was further observed that on average 2.04 ha of forest was being lost every year through anthropogenic activities, mainly farm expansion, charcoal business and firewood. In order to achieve VLFRs sustainability, the study recommends improvement of relationship and coordination among VLFRs key stakeholders, participatory preparation of forest management plans, enforcement of community forest management bylaws, and use of energy saving stoves to reduce overdependence on forests as source of energy.展开更多
Land degradation and sedimentation has been increasingly a crucial problem in upper Wabe-Shebele catchment, south eastern Ethiopia over the last two decades. Nevertheless, so far no detail research has been conducted ...Land degradation and sedimentation has been increasingly a crucial problem in upper Wabe-Shebele catchment, south eastern Ethiopia over the last two decades. Nevertheless, so far no detail research has been conducted to assess such problem. Therefore, the present study was conducted at Melka Wakena Catchment of Upper Wabe Shebelle Watershed to identify the trends of land use and land cover change and its effects on hydrology and land degradation. To achieve the objectives of the study different data sources such as satellite images, climate and rivers gage data;soil sample data were collected and analyzed using relevant corresponding up to dated software. Based on pre-defined criterion, available satellite images for the years 1986, 2011, and 2015 were analyzed using ERDAS, ENVI and ArcGIS softwares. The study catchment stream flow and soil erosion information were computed using SWAT model. MUSLE was employed to assess the amount of sediment yields and rate of soil loss existed in the study area. The study showed that significant land use and land cover changes were recorded during the past nearly three decades. This change has been directly affecting the hydrology and sedimentation of the catchment. The annual surface runoff varied between 45.65 mm and 332.29 mm. The amount of surface runoff was generally increased from 1990 to 2010, whereas decreased until 2013 before beginning the increasing trend. The result of the sediment yield analysis showed that there was a general increasing trend from 1992 to 2010 and then declined up to 2013 before it started the rising trend. From the simulated results, it was observed that the long-term mean soil loss was 20.22 t/ha. Sustainable integrated watershed management practices should be practically implemented throughout the landscape of the catchment from upper to down streams. Above all, dam buffer area needs to be demarcated and protected from the current settlement: cultivation and over grazing.展开更多
Dufuya wetland gardens and Insukamini irrigation scheme in Lower Gweru communal areas of Gweru district are two examples of how rural communities can be self-reliant if they are capacitated. This study sought to compa...Dufuya wetland gardens and Insukamini irrigation scheme in Lower Gweru communal areas of Gweru district are two examples of how rural communities can be self-reliant if they are capacitated. This study sought to compare crop diversity between these two vegetable producing schemes. The location of the two areas and the selected plots were determined using the GPS (global positioning system) hand receiver. Maps of the quadrants were produced in a GIS (geographic information system) on a computer. Simpson's index D = sum (pi2) was used to measure crop diversity while the Shannon-Weiner index (/4) was used to measure crop evenness. Results show that although both schemes are viable, Dufuya Gardens have higher crop diversity than Insukamini irrigation scheme. The study recommends that AGRITEX officers at Insukamini must advise farmers to diversify their crops in order for their produce to be more competitive on the market and also to cushion farmers against the effects of natural hazards. Given the success of the two schemes, the government must seriously consider sustainable utilization of the many small-scale dams and wetlands lying idle across the country for crop production in order to empower poor rural communities as well as alleviate poverty.展开更多
The conversion of forested areas to non-forest land was a series problem in study area of Goba district. The objectives of this study were to assess the trends, causes and effects of deforestation in Goba district, Ba...The conversion of forested areas to non-forest land was a series problem in study area of Goba district. The objectives of this study were to assess the trends, causes and effects of deforestation in Goba district, Bale zone, Ethiopia. Descriptive research method was employed to achieve these stated objectives. Satellite image of the three times and socio-economic survey were the main data sources for this study. ERDAS imagine 9.2 and ArcGIS 10 tools were applied for land use and land cover type classification, and analysis and mapping. These land use land and over change data were obtained from USGS. Socio-economic data collected through questionnaires, focus group discussions and interviews on the causes and impacts of land use and land cover change were analyzed quantitatively using SPSS software and content analysis for qualitative data. These analyzed data were expressed in percent and in words. The result shows that there was variation in the extent of land use and land cover change among different categories/classes at different study periods. Open area and Bush land showed decreasing change during first period of comparison and increasing change in the second period of comparison. In contrast, agricultural area, Bale temperate vegetation and built up area showed increasing. Built up area, agricultural area and Bale temperate vegetation increased by 80.05, 15.84, and 7.40 percent respectively, however, open area, grassland, forest land and bush land decreased by 1.58, 1.21, 0.97, and 0.28 percent per year for the last 29 years respectively. In general, in study district forest cover was 50.87% of the total area in 1986 and decreased to 36.57% in 2015 whereas agricultural area was increased from 3.45% to 19.28% respectively. This implies an increasing agricultural area at the expense of other land use cover categories, particularly natural forest. The study indicated that increasing population, forest fire and fuel wood consumption, overgrazing, and agriculture and settlement expansion and road construction caused forest cover change in the district. A decrease in livelihood incomes, volume of the surface water and in contrary increase in rain fall and temperature variability and forest product costs were among the major observed effects of deforestation in study area. Based on these findings, the study recommends the need to introduce and develop agricultural extension services, alternative energy sources and awareness raising services to the study area.展开更多
The fresh water system is most critical for sustainability of life. In present days the world is facing a shortage of potable water. Though Ethiopia is known as “The water tower of East Africa” yet it is facing seve...The fresh water system is most critical for sustainability of life. In present days the world is facing a shortage of potable water. Though Ethiopia is known as “The water tower of East Africa” yet it is facing severe water shortage that leads to poor agricultural productivity and imparts serious negative impact on human lives. It is essential to develop water resources in a sustainable way to ensure food security and economic development. The water scarcity is due to the lack of resource management and due to the changes in environmental factors. In Ethiopia ground water is a major source of drinking water to vast rural population. The country’s perennial water budget depends on the ground and spring water system. The ever increasing population, mismanagement and global climatic changes are having an adverse impact on these resources. To harvest the available resources in a sustainable way will help to meet the needs of present era without compromising the future generation. The present study is an approach to compare and utilize the traditional water harvesting practices of Himalaya in Ethiopian highlands. A detailed study of the water sources and mechanism of ground water, geology and social management system of their water resources were studied booth side. Further application of the indigenous technical knowledge for sustainable of the ground water is proposed based on Himalayan practices. The Ethiopian “Minches” could be preserved and better utilized by adopting the merits of time tested indigenous management system of “Naule” of Himalaya.展开更多
The research presented in this thesis reveals the level of rightness of the recurrence Prediction systems by correlated with geospatial effect. The Geospatial technology elements split up: Geographic Information Syste...The research presented in this thesis reveals the level of rightness of the recurrence Prediction systems by correlated with geospatial effect. The Geospatial technology elements split up: Geographic Information System (GIS), Remote Sensing (RS) and Global Positioning System (GPS) consolidated into this technique in light of the fact that the vast majority of the components in radio wave propagation are geographic highlights. In this exploration, ICEPAC remote arranging programming is tried in a field test completed in Tigray and Afar district. The consequence show that, the Prediction programming doesn’t put, day by day, regular and month to month topographical marvels into thought. Moreover, it doesn’t demonstrate the correct area of the radio stations. Furthermore, the new proposed ICEPAC Calibration algorithm anticipates a good Signal quality for frequencies in the vicinity of 1.5 MHz up to 30 MHz. The total result showed that Geographical Information Systems (GIS) are getting to be noticeably valuable apparatuses in accumulation, stockpiling, control and portrayal of Geo spatial information and also the RS and GIS situated Signal quality forecast can essentially enhance forecast quality contrasted with the hypothetical free space demonstration which does not consider any Geo spatial and neighborhood landscape highlights impacts.展开更多
文摘Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss costs a profound amount of the national GDP and deters land productivity.Quantifying soil loss and prioritizing areas for conservation is imperative for proper planning and resource management.Therefore,this study aimed at estimating the mean annual soil loss rate of Gilgel Abay watershed which has critical implications on Lake Tana and Abbay River(Upper Blue Nile River),using RUSLE and morphometric analysis methods.Datasets including rainfall,soil,Digital Elevation Model and land use/land cover were used to generate important parameters required for the soil loss estimation.Data collected through field observation,consultation with experts and document analysis were used for validation purposes.The results of the study reveal that the watershed experienced an average soil loss rate of 39.8 t ha^(-1)yr^(-1).Subsequently,nearly 25%(37,038 ha)of the watershed is threatened by moderate to very severe soil loss.Among the four sub watersheds,sub watershed 3(S3)and sub watershed 4(S4),which consist of about 65%(105,000 ha)of the total area of the study watershed,experienced an annual soil loss rate of over 30 t ha^(-1)yr^(-1).The amount of soil loss that the study watershed has experienced is above the soil loss tolerance level of Ethiopia(2-18 t ha^(-1)yr^(-1))and the tropical region(10 t ha^(-1)yr^(-1)).Similarly,the results of morphometric analysis showed that the studied watershed has S-shaped hypsometric curve,an indication for maturity stage of landscape development.The studied watershed is also characterized by a non-circular shaped drainage with rugged and dissected topography that contributes to high flash flood,peak discharge and incidence of soil loss.The result of both models signified that S3 and S4 are highly susceptible to soil erosion.Therefore,these two sub watersheds need priority for soil and water conservation(SWC)measures.Furthermore,the study demonstrated the importance of the integration of different models in the identification of soil erosion prone areas and prioritization for the proper implementation of SWC measures.
文摘Modeling urban land-use dynamics is critical for urban experts’and infrastructure managers’planning.This study attempts to explore the land-use/land-cover(LULC)dynamics of Gondar using satellite images from 1984 to 2020.Markov-Chain and Cellular Automata(MC-CA)models have been recognized as performing well in predicting urban land-use change.However,only a few models work in Ethiopia in general,and no study in Gondar has applied this approach to study urban land-use patterns.Therefore,Gondar land-use/land cover changes of Gondar were predicted using the MC-CA model in IDRISI.The built-up area in Gondar city covered 1413 ha(3%of the total area)in 1984 and increased to 2380 ha(5%)in 1994;21153 ha(45.5%)in 2004;22622 ha(48.7%)in 2014;and 23427 ha(50.5%)in 2020.The area has been predicted to reach 57.5%in the 2050s,showing a faster increase that will cause a very vast loss of farmland.This will increase urban sprawl challenges as well as overall environmental disequilibrium in the preceding decade.Thus,innovative and careful structures and systems in urban planning are required to secure a sustainable urban future and to make our cities livable and competitive in the paradigm of sustainable cities.
文摘Land suitability analysis of Moringa oleifera tree cultivation is important to enhance its product,as the demand forthis tree for medicinal values and food sources is increasing worldwide.Therefore,this study aimed to assess suitableland for Moringa oleifera tree cultivation by using the integration of multi-criteria evaluation with geospatialtechnologies in the Dhidhessa catchment,western Ethiopia.Five parameters,namely:slope,land use and landcover(LULC),soil texture,land surface temperature,and rainfall data,were used in this study.The land suitabilityevaluation of Moringa oleifera is classified into three classes as highly suitable,moderately suitable,and notsuitable.The results revealed that,about 344.4 km2(12.2%)of the area is categorized into highly suitable,and2343.7 km2(83%)is moderately suitable for Moringa tree,whereas,137.2 km2(4.9%)is categorized as notsuitable for Moringa oleifera tree cultivation.Hence,based on the finding of the study,we suggested that farmers andother stakeholders can cultivate Moringa oleifera trees in the Dhidhessa catchment.
文摘The study examines the Spatial Pattern and Distribution of Crime in Suleja LGA, Niger State, Nigeria. The study used GIS and statistical methods to analyse the pattern and distribution of crime incidence in the study area. The records of each crime incidence were geocoded. Microsoft Excel was used to collate and organise the crime entries before they were imported into the ArcGIS Pro 2.0 environment. A geodatabase was created where the spatial and aspatial data were encoded and geospatial analysis was performed. The study reveals that the crime distribution pattern is generally clustered with a Global Moran’s I index of 0.097, a Z-score of 1.87, and a P-value < 0.06. Furthermore, the study reveals that armed robbery (61), kidnapping (40), car theft (33), culpable homicide (31), rape (29), and robbery (13) cases rank the highest in crime rate. Equally, findings of the study show that Chaza, Kwamba, Madalla, Suleja central, and Gaboda are the major crime hotspot zones at 90% confidence, as analysed using the Getis-Ord Gi* (Hot spot analysis) spatial statistics tool in ArcGIS Pro 2.0. The research therefore recommends that more effort be put into fighting crime, especially in areas where there are low-security formations, as they mostly have the highest record of crimes committed. Also, the patrol units should be equipped with GPS for better surveillance and real-time tracking of criminal activities.
基金Transport Canada for financial support and Yukon Highways and Public Works for their support,logistics and assistance during instrumentation at the new Beaver Creek Culvert and information regarding the rules for construction of culverts in Yukon
文摘Temperature and water flow through a culvert beneath the Alaska Highway near Beaver Creek,Yukon,were measured at hourly intervals between June and October 2013.These data were used to simulate the effect of the culvert on the thermal regime of the road embankment and subjacent permafrost.A 2-D thermal model of the embankment and permafrost was developed with TEMP/W and calibrated using field observations.Empirical relations were obtained between water temperatures at the entrance to the culvert,flow into the culvert,and water temperatures inside the structure.Water temperatures at the entrance and inside the culvert had a linear relation,while water temperatures inside the culvert and water flow were associated by a logarithmic relation.A multiple linear regression was used to summarize these relations.From this relationship,changes in the flow rate and water temperatures at the entrance of the culvert were simulated to obtain predicted water temperatures in the culvert.The temperatures in the culvert were used in the thermal model to determine their effects on the ground thermal regime near the culvert.Variation of ±10% in water flow rate had no impact on the thermal regime underneath the culvert.Variation of water temperature at the entrance of the culvert had a noticeable influence on the thermal regime.A final simulation was conducted without insulation beneath the culvert.The thaw depth was 30 cm with insulation,and 120 cm without insulation,illustrating the importance of insulation to the ground thermal regime.
文摘This study was aimed at examining land cover changes for the last 35 years and its causative factors in Gilgel Abbay watershed by using GIS and remote sensing, survey and population data. The land use and cover changes study will help to apply the appropriate land use. The land cover/use status for the years 1973, 1986, 1995 and 2008 were examined using land sat images. The changes in different land cover units such as forest, wood and bush lands, grass, wetlands and water bodies, and farm and settlements were analyzed. Population change, tenure, poverty and lack of market and credit facilities in the watershed area were analyzed as causes of land cover changes. The results of the study have shown that during the last 35 years forest, grass lands, wetlands and lake areas were converted to farm and settlement areas. There was rapid increase of population with growth rates of 4.9% and 3.5% (1984-1994 and 1994-2007), respectively per annum which caused more land cover changes.
文摘Livelihood assets are a matter of high concern for secured survival.Drought-prone Gamo lowland households have differential access to livelihood resources which indicates the varying capacity of resisting to shocks.The main objective of this study is to explore the impacts of livelihood assets on livelihood security in the drought-prone Gamo lowlands.Multistage sampling procedures were employed to select the study sites and sample respondents.Primary data of households’capital assets and livelihood security status were produced from 285 survey households,agricultural experts,key informants,focus group discussants,and field observation through transect walks.Descriptive and inferential statistics were used to analyze quantitative data,whereas discussions and annotations were employed for analyzing qualitative data.The Sustainable Livelihoods Framework is used with modifications to schematize the study conceptually.The findings indicated that the study households possessed combinations of livelihood resources differentially.Financial and natural capitals were found to be the most deficient and better-accessed capitals,respectively.The study also showed that lowland residents’access to assets has significant indications of livelihood security.Households’poor access to assets such as financial,information,and social capital demands raised attention of the concerned stakeholders and policy debates in the drought-prone rural setup.Hence,it has been concluded that the more assets are accessed,the stronger the capacity of the households to resist shocks,and better the livelihood security.Accordingly,enhancing people’s access to multiple livelihood assets is suggested to sustainably secure livelihoods.
文摘Previous studies in Delo-Mena district failed to provide conceptual framework about causes and impacts of deforestation including prediction of spatial location of future deforestation. The study was aimed at investigating spatiotemporal dynamics and prediction of future trends of deforestation in this area. Three periods Landsat images were downloaded and preprocessed using ENVI 4.3. Supervised classification technique was employed for image classification. Land Change Modular used to predict deforestation based on transition between 2000 and 2015 along three driving variables (road distance, settlement and soil). Six land-use land-cover classes were classified for three periods. The result indicated that the forest areas were 91,339, 73,274 and 70,481 hectors in year 2000, 2010 and 2015, respectively. This forest area was reduced by 20% between 2000 and 2010 at annual rate of 2%. Between 2010 and 2015, a forest area was lost by 4% with annual rate of 1%. This deforestation rate was greater than global rates and was lower than rates of south eastern African countries. Farmland expansion was a major cause of deforestation contributed to the annual forest loss by 4.9% and 36% over different periods. In 2030, about 33,243 hectors of a forest area would be expected to disappear that implied emission of about 17 million ton of carbon dioxide. Fuelwoods shortage and loss of biodiversity were perceived as impacts of deforestation. Farm-land and settlement were found increasing at expense of vegetation. Forest plantation, supply of fuel efficient technology and community mobilization were recommended that would be emphasized by the forestry sector based at the district office.
文摘As a hazard, flood is an extremely important indicator of how a city is resilient to waterborne diseases and epidemics. Over many decades, flood as a hazard has been a major factor in inducing displacement of marginalized section of the people. Austin city within Central Texas has been identified as one of the major hotspots for flooding in recent decades. Thus, the objectives of the paper are two folded: 1) Empirically, we analyzed and mapped out the susceptibility levels from the factors of physical environments to assess the risk of urban flooding (rainfall data, surface water bodies and topography);in Austin, Texas and 2) Methodologically, we created a re-useable ArcGIS scripting tool that can be used by researchers to automate the process of flood risk modelling with certain criteria. The paper showcases a novel time sensitive building of a tool which will enable better visibility of flood within the city of Austin.
文摘The Clean Development Mechanism,a flexibility mechanism contained in the KyotoProtocol, offers China an important tool to attractinvestment in clean energy technology and processesinto its electricity sector. The Chinese electricitysector places centrally in the country’s economy andenvironment, being a significant contributor to theacid rain and air pollution problems that plague manyof China’s cities and regions, and therefore a focusof many related energy and environmental policies.China’s electricity sector has also been the subjectof a number of economic analyses that have showedthat it contains the highest potential for clean energyinvestment through the Clean DevelopmentMechanism of any economic sector in China. Thismechanism, through the active participation frominvestors in more industrialized countries, can helpalleviate the environmental problems attributable toelectricity generation in China through advancingsuch technology as wind electricity generation, cleancoal technology, high efficient natural gas electricitygeneration, or utilization of coal mine methane. Inthis context, the Clean Development Mechanismalso compliments a range of environmental and energypolicies which are strategizing to encourage thesustainable development of China’s economy.
文摘Objective-To investigate forest cover change in Masese Local Forest Reserve and its effects on the livelihoods of the dependent communities;to establish the occurrence of forest cover change in Masese Local Forest Reserve;to determine the extent of forest cover change in Masese from 1990to 2005;to determine the tree species that have been affected by forest cover change in Masese; and to assess the effects of forest cover change on the livelihoods of the dependent communities. Methods-Interviews and questionnaire were conducted with a proportion of 36households from Maondo and 84households from Mulimambango settlements.Scenes of landsat images of 1990,2000, 2005and Earth Google image for Masese were used for map analysis.Also remote sensing was used to analyze landsat images and Google image to detect forest and non-forest classes.Results and Conclusion-Forest cover change has adverse implication on the provision of wood forest products and nonwood forest products to the dependent local communities.The declining status of dominant Baikiaea Forest that has exploitable species for building materials and fuel wood has affected the livelihoods of the dependent local communities.There is also increased cost and shortage of fire wood and building materials due to deforestation in Masese Forest Reserve.
文摘A systematic analysis of land use/cover change is so decisive to exactly understand the extent of change and take essential measures to curb down the rate of changes and protect the land cover resources sustainably. This land use/land cover change study was conducted in Agarfa district of Bale zone, Oromia Regional State, Southeastern Ethiopia. The objectives of this study were to evaluate the trends, drivers and its socio-economic and environmental implication in study area. A descriptive research method was employed to achieve the intended objectives of the study. In the three years (1976, 1995, and 2014) Landsat Satellite images and socio-economic survey were the main data sources for this study. ERDAS Imagine and Arch-GIS tools were used to classify and generate land use/land cover maps of the study area. Survey questionnaires, key informant interviews, and field observation were employed to obtain information on drivers and its socio-economic and environmental implication in the district. The results show that the land use/land cover of the study area had changed dramatically during the period of 38 years. A rapid loss of forest land and shrub land cover in the landscape took place between 1976 and 2014. Conversely, agriculture and grazing lands were increased by 30% and 42% respectively at the expense of the lost land use/land cover types. Forest land is the most converted cover type during the entire study period. In the 38 years, forest lands diminished by over 65% of the original forest cover that was existed at the base year (1976). Local climate change, declining agricultural productivity and livestock quantity and quality and scarcity of fuel wood and constructional materials were some of the socio-economic and livelihood impacts of land use and land cover change of the study area. Thus, this finding affords information to land users and policy makers on extent of the change and social forces leading to this changes and its subsequent implication on local socio-economic and environmental conditions of the study area.
文摘The study attempted to understand indigenous small farming systems and its challenges with the framework of agricultural modernisation in Konso community, Southern Ethiopia. There were 400 household heads from different wealth rank and farming practices considered for in-depth interview. This was completed by focus group discussions and plot level investigations. The findings indicated that the community and landscape are characterized by heterogeneity, implying the challenges of introducing standard modern agricultural technologies. Moreover, the community has wide range of indigenous soil and water conservation (SWC) measures geared to production and protection. For example, in a single plot with a size of less than 0.4 ha, it was possible to produce up to 35 plant spices with multiple functions. The evaluation of the modern agricultural extension services by the community indicates that about 17% was found to be positive in line to diffusion of new technologies and rehabilitation of degraded lands. However, the strengths seem to be offset by the weaknesses (61%) with respect to food security, resilience to drought, synergy with indigenous knowledge, empowerment in decision-making, The findings underlined that to assure food security and sustainable resource management, creating policy environment for holistic and integrated approach, supporting indigenous practices and empowering community in decision making are fundamental.
文摘This study was conducted in Melka Wakena catchment;south eastern Ethiopia to assess land use/cover change (LULCC) and topographic elevation effect on selected soil quality/fertility parameters. 144 soil samples collected from 0 - 30 cm depth under three land cover types across three elevation gradients were analysed for selected soil quality/fertility parameters. Data were statistically analyzed using analysis of variance (ANOVA) and mean comparisons were made using Least Significant Difference (LSD). The soil properties examined generally showed significant variations with respect to land-use/land cover changes and elevation. Soil particles, soil organic carbon, total N, pH, available phosphorus, potassium and calcium content significantly decreased as forestland is converted into cropland/grassland. Heaviest soil deterioration was recorded in soils under cropland and followed by grassland soils. The conversion of natural forest to different land uses without proper soil conservation and management practices resulted in the overall decline of soil fertility quality. Thus, integrated land resource management approach is indispensable for sustaining agricultural productivity and the environmental health of the Melka Waken a catchment.
文摘Prospects and challenges of Village Lands Forest Reserves (VLFRs) in Mbarali district, southern Tanzania were investigated. Data were collected through questionnaire surveys, in-depth key informant interviews, physical field visits and documentary reviews. A total of 44 subjects were involved in the study. SPSS, Microsoft Excel and content analysis were used in data analysis. Findings indicated that inadequate capacity building, passive community participation and involvement in VLFRs management fostered the continued forest degradation and deforestation in the study area. It was further observed that on average 2.04 ha of forest was being lost every year through anthropogenic activities, mainly farm expansion, charcoal business and firewood. In order to achieve VLFRs sustainability, the study recommends improvement of relationship and coordination among VLFRs key stakeholders, participatory preparation of forest management plans, enforcement of community forest management bylaws, and use of energy saving stoves to reduce overdependence on forests as source of energy.
文摘Land degradation and sedimentation has been increasingly a crucial problem in upper Wabe-Shebele catchment, south eastern Ethiopia over the last two decades. Nevertheless, so far no detail research has been conducted to assess such problem. Therefore, the present study was conducted at Melka Wakena Catchment of Upper Wabe Shebelle Watershed to identify the trends of land use and land cover change and its effects on hydrology and land degradation. To achieve the objectives of the study different data sources such as satellite images, climate and rivers gage data;soil sample data were collected and analyzed using relevant corresponding up to dated software. Based on pre-defined criterion, available satellite images for the years 1986, 2011, and 2015 were analyzed using ERDAS, ENVI and ArcGIS softwares. The study catchment stream flow and soil erosion information were computed using SWAT model. MUSLE was employed to assess the amount of sediment yields and rate of soil loss existed in the study area. The study showed that significant land use and land cover changes were recorded during the past nearly three decades. This change has been directly affecting the hydrology and sedimentation of the catchment. The annual surface runoff varied between 45.65 mm and 332.29 mm. The amount of surface runoff was generally increased from 1990 to 2010, whereas decreased until 2013 before beginning the increasing trend. The result of the sediment yield analysis showed that there was a general increasing trend from 1992 to 2010 and then declined up to 2013 before it started the rising trend. From the simulated results, it was observed that the long-term mean soil loss was 20.22 t/ha. Sustainable integrated watershed management practices should be practically implemented throughout the landscape of the catchment from upper to down streams. Above all, dam buffer area needs to be demarcated and protected from the current settlement: cultivation and over grazing.
文摘Dufuya wetland gardens and Insukamini irrigation scheme in Lower Gweru communal areas of Gweru district are two examples of how rural communities can be self-reliant if they are capacitated. This study sought to compare crop diversity between these two vegetable producing schemes. The location of the two areas and the selected plots were determined using the GPS (global positioning system) hand receiver. Maps of the quadrants were produced in a GIS (geographic information system) on a computer. Simpson's index D = sum (pi2) was used to measure crop diversity while the Shannon-Weiner index (/4) was used to measure crop evenness. Results show that although both schemes are viable, Dufuya Gardens have higher crop diversity than Insukamini irrigation scheme. The study recommends that AGRITEX officers at Insukamini must advise farmers to diversify their crops in order for their produce to be more competitive on the market and also to cushion farmers against the effects of natural hazards. Given the success of the two schemes, the government must seriously consider sustainable utilization of the many small-scale dams and wetlands lying idle across the country for crop production in order to empower poor rural communities as well as alleviate poverty.
文摘The conversion of forested areas to non-forest land was a series problem in study area of Goba district. The objectives of this study were to assess the trends, causes and effects of deforestation in Goba district, Bale zone, Ethiopia. Descriptive research method was employed to achieve these stated objectives. Satellite image of the three times and socio-economic survey were the main data sources for this study. ERDAS imagine 9.2 and ArcGIS 10 tools were applied for land use and land cover type classification, and analysis and mapping. These land use land and over change data were obtained from USGS. Socio-economic data collected through questionnaires, focus group discussions and interviews on the causes and impacts of land use and land cover change were analyzed quantitatively using SPSS software and content analysis for qualitative data. These analyzed data were expressed in percent and in words. The result shows that there was variation in the extent of land use and land cover change among different categories/classes at different study periods. Open area and Bush land showed decreasing change during first period of comparison and increasing change in the second period of comparison. In contrast, agricultural area, Bale temperate vegetation and built up area showed increasing. Built up area, agricultural area and Bale temperate vegetation increased by 80.05, 15.84, and 7.40 percent respectively, however, open area, grassland, forest land and bush land decreased by 1.58, 1.21, 0.97, and 0.28 percent per year for the last 29 years respectively. In general, in study district forest cover was 50.87% of the total area in 1986 and decreased to 36.57% in 2015 whereas agricultural area was increased from 3.45% to 19.28% respectively. This implies an increasing agricultural area at the expense of other land use cover categories, particularly natural forest. The study indicated that increasing population, forest fire and fuel wood consumption, overgrazing, and agriculture and settlement expansion and road construction caused forest cover change in the district. A decrease in livelihood incomes, volume of the surface water and in contrary increase in rain fall and temperature variability and forest product costs were among the major observed effects of deforestation in study area. Based on these findings, the study recommends the need to introduce and develop agricultural extension services, alternative energy sources and awareness raising services to the study area.
文摘The fresh water system is most critical for sustainability of life. In present days the world is facing a shortage of potable water. Though Ethiopia is known as “The water tower of East Africa” yet it is facing severe water shortage that leads to poor agricultural productivity and imparts serious negative impact on human lives. It is essential to develop water resources in a sustainable way to ensure food security and economic development. The water scarcity is due to the lack of resource management and due to the changes in environmental factors. In Ethiopia ground water is a major source of drinking water to vast rural population. The country’s perennial water budget depends on the ground and spring water system. The ever increasing population, mismanagement and global climatic changes are having an adverse impact on these resources. To harvest the available resources in a sustainable way will help to meet the needs of present era without compromising the future generation. The present study is an approach to compare and utilize the traditional water harvesting practices of Himalaya in Ethiopian highlands. A detailed study of the water sources and mechanism of ground water, geology and social management system of their water resources were studied booth side. Further application of the indigenous technical knowledge for sustainable of the ground water is proposed based on Himalayan practices. The Ethiopian “Minches” could be preserved and better utilized by adopting the merits of time tested indigenous management system of “Naule” of Himalaya.
文摘The research presented in this thesis reveals the level of rightness of the recurrence Prediction systems by correlated with geospatial effect. The Geospatial technology elements split up: Geographic Information System (GIS), Remote Sensing (RS) and Global Positioning System (GPS) consolidated into this technique in light of the fact that the vast majority of the components in radio wave propagation are geographic highlights. In this exploration, ICEPAC remote arranging programming is tried in a field test completed in Tigray and Afar district. The consequence show that, the Prediction programming doesn’t put, day by day, regular and month to month topographical marvels into thought. Moreover, it doesn’t demonstrate the correct area of the radio stations. Furthermore, the new proposed ICEPAC Calibration algorithm anticipates a good Signal quality for frequencies in the vicinity of 1.5 MHz up to 30 MHz. The total result showed that Geographical Information Systems (GIS) are getting to be noticeably valuable apparatuses in accumulation, stockpiling, control and portrayal of Geo spatial information and also the RS and GIS situated Signal quality forecast can essentially enhance forecast quality contrasted with the hypothetical free space demonstration which does not consider any Geo spatial and neighborhood landscape highlights impacts.