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
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
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
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
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.
