Tilahun Mulatu - Academia.edu (original) (raw)

Papers by Tilahun Mulatu

City and Environment Interactions

Environment, Development and Sustainability

The need for participation of farmers in the research process was felt when recommendation from r... more The need for participation of farmers in the research process was felt when recommendation from research centers were not transferred to farmers. The purposes of this report are to understand and describe crop and animal production practices, prioritized major constraints and suggest possible technological intervention in Adami Tulu area. Secondary data and exploratory survey were conducted between August-October, 1988. About 50 farmers from 10 peasant Associations were interviewed and their fields were visited. The verification (formal) survey was conducted in March, 1990. A multistage sampling procedure was used toselectsam ple farmers. All non-accessible service cooperatives were omitted purposely. A questionnaire was designed and administered to 50 randomly selected farmers. The survey area is 130-150 km, south o f Addis Abeba. The altitude ranges between 1600m to 1860m. The average annual maximum temperature is 25°C-27°C and the minimum is 12°C-16°C. The average annual rainfall is 736-782mm; July receiving the highest. The soil is sandy to clay loam and the pH is 6.5-9.1. The study area covers about 18200 households and the people are mostly muslim. There is one asphalt road that passes through Meki-Ziway and the feeder road network is fair. About 40% of the fanners do not receive intensive extension services. The average extension agent farmer ratio is 1:1658. Farmers grow many maize varieties to avoid risk and to meet different objectives. These include Limat, Katuinani, A-511 and Sheye. When ever there is delay of rainfall in M arch-April. Haricot bean and tef areas increase at the expense o f maize. Early maturity is the major criteria used by 80% of maize growers. High yield and quality for making injera are also considered as important criteria. Farmers require early-maturing varieties for two reasons (1) unreliability of rainfall during early and late in the season and (2) to shorten food shortage period by using green cobs. Higher yield was considered the most important criteria in selecting sorghum varieties. Katumani among maize varieties and Gcbabe among sorghum varieties are most preferred. On average, a family has 3.4 ha of which 3 0 ha is cultivated, a family size of 8 persons with 1.6 persons working full time on farm, and 2.2 oxen. July-August is the most busy period. The most important crops grown in the area include maize, haricot bean and tef. Haricot bean is the major cash crop. Tef and maize are the second and the third. Other less important crops include Sorghum, Wheat, and Barley. Fanners allocate the most fertile land to maize. Tef, barley and wheat are grown on soils o f medium fertility level due to lodging and weed problem. Haricot bean is grown on least fertile soils so that weed infestation will be low. Only 20% o f the farmers followed a portion of their farm in 1989 cropping season. Land preparation for maize is started in March. On average, maize fields are plowed 4 times. The average seed rate is about 89 kg ha 1 which is much higher than the recommended seed rate (25-30 kg ha l) in order to reduce risk of poor seedling emergence that may arise due to moisture stress. Soil fertility, weed intensity and seed quality also affect seed rate. The main reason for not planting in rows is shortage of labor. Oxen cultivation-"Shilshallo"-is done 4-5 weeks after planting in July. About half of the farmers thin maize to get livestock feed and to reduce plant population. About 35% o f the farmers weed maize once and 63% twice. Only 12% of the sample farmers used chemical fertilizer on maize in 1989 cropping season. Stalk borer is the major pest 1 on maize. M aize is harvested in October-November and the average maize yield in normal years is about 1400 kg ha l. The most common haricot bean variety is mexican-142. Haricot bean fields are plowed 2-3 times. Haricot bean is planted from end of J une to mid-July. The average seeding rate is about 102 kg h a'1. This rate is higher than the recommended seeding rate (70 kg ha ') as a substitute for weeding. Haricot bean is not weeded due to labor shortage. It is harvested in October and the average yield in normal years is 900 kg ha'1. Red Tef variety is the most common and it is grown by 64% of the sample farmers and covers about 13% o f the total cultivated land. Tef fields are plowed 3-4 times. The average seeding rate is 35 kg ha 1 and planting is done in July. Thirty percent of the sample farmers used fertilizer in 1989 cropping season. About 57% of the sample farmers weeded their tef once and 30% did not. Few farmers used herbicides on Tef. Tef is harvested in October-November and the average yield in good year is about 1100 kg ha'1. The most common sorghum variety grown n the survey area is Gababe. The average number o plowing sorghum field is 3 times. On average fanners use a seed rate of 17 kg ha'1. Oxen cultivation is done 5-6 weeks after planting and it is supplemented with hand weeding, 10-15 days later. Almost all of the farmers do not use fertilizer on sorghum fields. Quelea bird is reported as a pressing problem in sorghum production. W heat is usually planted in early July with an average seed rate of 126 kg ha'1. Wheat is weeded once and about half of the sample farmers used fertilizer in 1989 cropping season. Barley is planted in late June with an average seeding rate o f 188 kg ha'1. Only one-fifth of the sample farmers used fertilizer on barley. About 68% of the sample farmers have at least a pair of oxen and 84% at least own a cow. The survey area seems better support goats than sheep. Cows give birth in February-March when management of the dam is not convenient. Cows are milked twice a day for 6-8 months. Feed is commonly scarce from March to end of June. Some farmers are transhumans; "godantu Diseases and drought are serious problems of livestock production. Due to erratic nature of rain fall, long cycled crops and varieties are substituted by short cycled crops and varieties. Hararge and sheye varieties are being replaced by Katumani and Militia varieties. Relish crops such as field pea, lentil, and faba bean are decreasing in importance due to sever disease and pest attack. Livestock number is declining primarily due to drought and limited field availability. Goats are increasing since they can feed on shrubs. Environmental constraints (early and late season stresses), dry season livestock feed shortage, stalk borer on maize and sorghum, rust on haricot bean and wheat, birds on sorghum, weeds on Tef, low soil fertility and animal disease are the major constraints of crop and livestock production in the study area. The following measures are suggested to overcome the above mentioned constraints. These include: ■ Screening short-cycled and/or drought tolerant crops or varieties. ■ Moisture conservation strategics (tied ridging). ■ Introduction of forage shrubs as a hedge and alley cropping. ■ Screening pest and disease tolerant varieties ■ Screening herbicides at least for one of the major crops. ■ Agroforestry and fertilizer response trials.

Amphibia is the least studied group of vertebrates in Ethiopia. Besides contributions from a few ... more Amphibia is the least studied group of vertebrates in Ethiopia. Besides contributions from a few expeditions in the past, the effort given to amphibian studies among academicians and researchers has been very minimal until recently. This is the cause for the lack of detailed information on amphibians, even in known protected areas. Despite the huge role of forest fragments in southwestern Ethiopia for conserving amphibian diversity, the focus given for amphibian conservation within these forest fragments is almost insignificant. The increasing rate of deforestation and fungal infection are threatening the survival of anurans (tailless amphibians) of the region. The current study focused on determining the anuran (tailless amphibian) diversity in a recently recognized reserve, the Yayu Coffee Forest Biosphere Reserve (YCFBR), in southwestern Ethiopia. A total of 101 individuals, from ten different species (nearly 6.5% of the total number of known species in the country), was collected from four different habitats including forests, stream sides, swamps, and temporary ponds, with a greater number collected or observed in swampy areas. As expected, the wet season collection yielded a greater number of collected individuals than the dry season collection. These results indicated the potential of the reserve for conserving regional amphibian fauna. Future conservation measures should focus on reducing the extent of deforestation, particularly in protected areas, while also estimating the magnitude of fungal infection among diverse anuran species of the region.

Land, 2019

Urban development is occurring in many Sub-Saharan Africa cities and rapid urbanization is underw... more Urban development is occurring in many Sub-Saharan Africa cities and rapid urbanization is underway in the East African city of Addis Ababa, Ethiopia. In an effort to address urban poverty and increase homeownership opportunities for low and middle-income residents, the City Administration of Addis Ababa initiated a large-scale housing development project in 2005. The project has resulted in the completion of 175,000 units within the city with 132,000 more under construction. To understand the impacts of both rapid growth and the housing program’s impact on the city’s urban form, we compared the type and distribution of land uses in Addis Ababa, Ethiopia, between 2006 with 2016 using hand-digitized, ortho-rectified satellite images in Geographic Information Systems (GISs). While residential density has increased, overall density has decreased from 109 people/ha to 98 people/ha. We found that between 2006 and 2016, land occupied by residential housing increased from 33% to 39% and th...

Global Ecology and Conservation, 2016

Context The ''Montado'', a human shaped oak agro-forestry dominated landscape of South Western Eu... more Context The ''Montado'', a human shaped oak agro-forestry dominated landscape of South Western Europe has been experiencing series of changes following the implementation of different agricultural policies. Such changes are responsible for shifting the structure and composition of ''Montado'' landscape and hence the biodiversity of the system, either by agriculture abandonment or intensification. Traditional oak agro-forestry management practices, which focused on improving the ecological status of a single and common land use (oak agro-forestry), is taken as a conservation paradigm against the perceived changes in the system. Aims We aimed to identify the effect of oak agro-forestry management on ''Montado'' biodiversity as indicator for ecological status of ''Montado'' landscape. Methods A recently developed spatially explicit Stochastic Dynamic Methodology (StDM) was applied to model the spatial and temporal patterns of the land use/land cover changes and predict responses in biodiversity patterns, with a focus on passerine functional traits (grassland, woodland and generalist species richness), considering scenarios with and without oak agro-forestry management. Results Model outputs showed that oak agro-forestry management favored the expansion of oak agro-forestry at the expense of other land uses, mainly oak forest and agricultural areas. On the other hand, passerine richness exhibits a gradual decline facing the intensification of oak agro-forestry management practices, with higher declining rate observed for grassland passerine species. Conclusion The oak agro-forestry management does not seem to improve the ecological status of ''Montado'' landscape, and neither does its abandonment. Hence the conservation paradigm should focus on improving the multi-functionality of the system than merely focusing on a single and common land use

Journal of Physics: Conference Series, 2018

For direction finding problem of multi-target in the multi-input multi-output (MIMO) radar, a mul... more For direction finding problem of multi-target in the multi-input multi-output (MIMO) radar, a multi-target direction of arrival (DOA) estimation method with time reversal (TR) MIMO radar is proposed. Firstly, according to the echo signal matrix of MIMO radar, we use TR theory to establish the echo signal model of TR MIMO radar. Then, the echo signal of TR MIMO is performed with matched filter and vectorized processing on the basis of the waveform diversity of MIMO radar, which extends the virtual aperture of MIMO radar. Finally, the Multiple Signal Classification (MUSIC) algorithm is used to estimate the DOAs, improving the estimation performance greatly. Compared with the conventional MIMO, TR MIMO can effectively improve the echo signal gain and increase the virtual aperture. The simulation results show that TR MIMO can accurately estimate the angles even when the (signal noise ratio) SNR is -20dB, which demonstrates the effectiveness of proposed configuration.

City and Environment Interactions

Environment, Development and Sustainability

The need for participation of farmers in the research process was felt when recommendation from r... more The need for participation of farmers in the research process was felt when recommendation from research centers were not transferred to farmers. The purposes of this report are to understand and describe crop and animal production practices, prioritized major constraints and suggest possible technological intervention in Adami Tulu area. Secondary data and exploratory survey were conducted between August-October, 1988. About 50 farmers from 10 peasant Associations were interviewed and their fields were visited. The verification (formal) survey was conducted in March, 1990. A multistage sampling procedure was used toselectsam ple farmers. All non-accessible service cooperatives were omitted purposely. A questionnaire was designed and administered to 50 randomly selected farmers. The survey area is 130-150 km, south o f Addis Abeba. The altitude ranges between 1600m to 1860m. The average annual maximum temperature is 25°C-27°C and the minimum is 12°C-16°C. The average annual rainfall is 736-782mm; July receiving the highest. The soil is sandy to clay loam and the pH is 6.5-9.1. The study area covers about 18200 households and the people are mostly muslim. There is one asphalt road that passes through Meki-Ziway and the feeder road network is fair. About 40% of the fanners do not receive intensive extension services. The average extension agent farmer ratio is 1:1658. Farmers grow many maize varieties to avoid risk and to meet different objectives. These include Limat, Katuinani, A-511 and Sheye. When ever there is delay of rainfall in M arch-April. Haricot bean and tef areas increase at the expense o f maize. Early maturity is the major criteria used by 80% of maize growers. High yield and quality for making injera are also considered as important criteria. Farmers require early-maturing varieties for two reasons (1) unreliability of rainfall during early and late in the season and (2) to shorten food shortage period by using green cobs. Higher yield was considered the most important criteria in selecting sorghum varieties. Katumani among maize varieties and Gcbabe among sorghum varieties are most preferred. On average, a family has 3.4 ha of which 3 0 ha is cultivated, a family size of 8 persons with 1.6 persons working full time on farm, and 2.2 oxen. July-August is the most busy period. The most important crops grown in the area include maize, haricot bean and tef. Haricot bean is the major cash crop. Tef and maize are the second and the third. Other less important crops include Sorghum, Wheat, and Barley. Fanners allocate the most fertile land to maize. Tef, barley and wheat are grown on soils o f medium fertility level due to lodging and weed problem. Haricot bean is grown on least fertile soils so that weed infestation will be low. Only 20% o f the farmers followed a portion of their farm in 1989 cropping season. Land preparation for maize is started in March. On average, maize fields are plowed 4 times. The average seed rate is about 89 kg ha 1 which is much higher than the recommended seed rate (25-30 kg ha l) in order to reduce risk of poor seedling emergence that may arise due to moisture stress. Soil fertility, weed intensity and seed quality also affect seed rate. The main reason for not planting in rows is shortage of labor. Oxen cultivation-"Shilshallo"-is done 4-5 weeks after planting in July. About half of the farmers thin maize to get livestock feed and to reduce plant population. About 35% o f the farmers weed maize once and 63% twice. Only 12% of the sample farmers used chemical fertilizer on maize in 1989 cropping season. Stalk borer is the major pest 1 on maize. M aize is harvested in October-November and the average maize yield in normal years is about 1400 kg ha l. The most common haricot bean variety is mexican-142. Haricot bean fields are plowed 2-3 times. Haricot bean is planted from end of J une to mid-July. The average seeding rate is about 102 kg h a'1. This rate is higher than the recommended seeding rate (70 kg ha ') as a substitute for weeding. Haricot bean is not weeded due to labor shortage. It is harvested in October and the average yield in normal years is 900 kg ha'1. Red Tef variety is the most common and it is grown by 64% of the sample farmers and covers about 13% o f the total cultivated land. Tef fields are plowed 3-4 times. The average seeding rate is 35 kg ha 1 and planting is done in July. Thirty percent of the sample farmers used fertilizer in 1989 cropping season. About 57% of the sample farmers weeded their tef once and 30% did not. Few farmers used herbicides on Tef. Tef is harvested in October-November and the average yield in good year is about 1100 kg ha'1. The most common sorghum variety grown n the survey area is Gababe. The average number o plowing sorghum field is 3 times. On average fanners use a seed rate of 17 kg ha'1. Oxen cultivation is done 5-6 weeks after planting and it is supplemented with hand weeding, 10-15 days later. Almost all of the farmers do not use fertilizer on sorghum fields. Quelea bird is reported as a pressing problem in sorghum production. W heat is usually planted in early July with an average seed rate of 126 kg ha'1. Wheat is weeded once and about half of the sample farmers used fertilizer in 1989 cropping season. Barley is planted in late June with an average seeding rate o f 188 kg ha'1. Only one-fifth of the sample farmers used fertilizer on barley. About 68% of the sample farmers have at least a pair of oxen and 84% at least own a cow. The survey area seems better support goats than sheep. Cows give birth in February-March when management of the dam is not convenient. Cows are milked twice a day for 6-8 months. Feed is commonly scarce from March to end of June. Some farmers are transhumans; "godantu Diseases and drought are serious problems of livestock production. Due to erratic nature of rain fall, long cycled crops and varieties are substituted by short cycled crops and varieties. Hararge and sheye varieties are being replaced by Katumani and Militia varieties. Relish crops such as field pea, lentil, and faba bean are decreasing in importance due to sever disease and pest attack. Livestock number is declining primarily due to drought and limited field availability. Goats are increasing since they can feed on shrubs. Environmental constraints (early and late season stresses), dry season livestock feed shortage, stalk borer on maize and sorghum, rust on haricot bean and wheat, birds on sorghum, weeds on Tef, low soil fertility and animal disease are the major constraints of crop and livestock production in the study area. The following measures are suggested to overcome the above mentioned constraints. These include: ■ Screening short-cycled and/or drought tolerant crops or varieties. ■ Moisture conservation strategics (tied ridging). ■ Introduction of forage shrubs as a hedge and alley cropping. ■ Screening pest and disease tolerant varieties ■ Screening herbicides at least for one of the major crops. ■ Agroforestry and fertilizer response trials.

Amphibia is the least studied group of vertebrates in Ethiopia. Besides contributions from a few ... more Amphibia is the least studied group of vertebrates in Ethiopia. Besides contributions from a few expeditions in the past, the effort given to amphibian studies among academicians and researchers has been very minimal until recently. This is the cause for the lack of detailed information on amphibians, even in known protected areas. Despite the huge role of forest fragments in southwestern Ethiopia for conserving amphibian diversity, the focus given for amphibian conservation within these forest fragments is almost insignificant. The increasing rate of deforestation and fungal infection are threatening the survival of anurans (tailless amphibians) of the region. The current study focused on determining the anuran (tailless amphibian) diversity in a recently recognized reserve, the Yayu Coffee Forest Biosphere Reserve (YCFBR), in southwestern Ethiopia. A total of 101 individuals, from ten different species (nearly 6.5% of the total number of known species in the country), was collected from four different habitats including forests, stream sides, swamps, and temporary ponds, with a greater number collected or observed in swampy areas. As expected, the wet season collection yielded a greater number of collected individuals than the dry season collection. These results indicated the potential of the reserve for conserving regional amphibian fauna. Future conservation measures should focus on reducing the extent of deforestation, particularly in protected areas, while also estimating the magnitude of fungal infection among diverse anuran species of the region.

Land, 2019

Urban development is occurring in many Sub-Saharan Africa cities and rapid urbanization is underw... more Urban development is occurring in many Sub-Saharan Africa cities and rapid urbanization is underway in the East African city of Addis Ababa, Ethiopia. In an effort to address urban poverty and increase homeownership opportunities for low and middle-income residents, the City Administration of Addis Ababa initiated a large-scale housing development project in 2005. The project has resulted in the completion of 175,000 units within the city with 132,000 more under construction. To understand the impacts of both rapid growth and the housing program’s impact on the city’s urban form, we compared the type and distribution of land uses in Addis Ababa, Ethiopia, between 2006 with 2016 using hand-digitized, ortho-rectified satellite images in Geographic Information Systems (GISs). While residential density has increased, overall density has decreased from 109 people/ha to 98 people/ha. We found that between 2006 and 2016, land occupied by residential housing increased from 33% to 39% and th...

Global Ecology and Conservation, 2016

Context The ''Montado'', a human shaped oak agro-forestry dominated landscape of South Western Eu... more Context The ''Montado'', a human shaped oak agro-forestry dominated landscape of South Western Europe has been experiencing series of changes following the implementation of different agricultural policies. Such changes are responsible for shifting the structure and composition of ''Montado'' landscape and hence the biodiversity of the system, either by agriculture abandonment or intensification. Traditional oak agro-forestry management practices, which focused on improving the ecological status of a single and common land use (oak agro-forestry), is taken as a conservation paradigm against the perceived changes in the system. Aims We aimed to identify the effect of oak agro-forestry management on ''Montado'' biodiversity as indicator for ecological status of ''Montado'' landscape. Methods A recently developed spatially explicit Stochastic Dynamic Methodology (StDM) was applied to model the spatial and temporal patterns of the land use/land cover changes and predict responses in biodiversity patterns, with a focus on passerine functional traits (grassland, woodland and generalist species richness), considering scenarios with and without oak agro-forestry management. Results Model outputs showed that oak agro-forestry management favored the expansion of oak agro-forestry at the expense of other land uses, mainly oak forest and agricultural areas. On the other hand, passerine richness exhibits a gradual decline facing the intensification of oak agro-forestry management practices, with higher declining rate observed for grassland passerine species. Conclusion The oak agro-forestry management does not seem to improve the ecological status of ''Montado'' landscape, and neither does its abandonment. Hence the conservation paradigm should focus on improving the multi-functionality of the system than merely focusing on a single and common land use

Journal of Physics: Conference Series, 2018

For direction finding problem of multi-target in the multi-input multi-output (MIMO) radar, a mul... more For direction finding problem of multi-target in the multi-input multi-output (MIMO) radar, a multi-target direction of arrival (DOA) estimation method with time reversal (TR) MIMO radar is proposed. Firstly, according to the echo signal matrix of MIMO radar, we use TR theory to establish the echo signal model of TR MIMO radar. Then, the echo signal of TR MIMO is performed with matched filter and vectorized processing on the basis of the waveform diversity of MIMO radar, which extends the virtual aperture of MIMO radar. Finally, the Multiple Signal Classification (MUSIC) algorithm is used to estimate the DOAs, improving the estimation performance greatly. Compared with the conventional MIMO, TR MIMO can effectively improve the echo signal gain and increase the virtual aperture. The simulation results show that TR MIMO can accurately estimate the angles even when the (signal noise ratio) SNR is -20dB, which demonstrates the effectiveness of proposed configuration.