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1.
Accelerated pollution and eutrophication of rivers and streams because of human activity are a concern throughout the world and severe in Africa where Ethiopia is case in point. The objective of this study was to assess the urban impact on the ecological integrity of the Borkena River at the eastern escarpment of the central Ethiopian highlands. The water quality status and macroinvertebrate distribution and diversity of the river were assessed during the dry and wet seasons. Diversity indices revealed that a severe decline in the ecological integrity of the Borkena River downstream of Dessie and within Kombolcha towns in terms of macroinvertebrate abundance and composition. Clustering and ordination analysis clearly separated reference sites from urban impacted sites. At the urban-impacted sites, dissolved oxygen was also depleted to 0.5 mg/l and BOD5 values were reached to a level of above 1,000 mg/l, with extremely low biological diversity of pollution-sensitive taxa. These patterns are the result of a combination of rampant dumping of untreated wastes exacerbated by geologic, topographic, climatic and land use factors.  相似文献   
2.
Climate change (CC) is now recognized as posing a serious threat to the sustainable development of Addis Ababa city, Ethiopia. As a consequence, city authorities are showing increasing interest in combating CC by streamlining adaptation measures into city development planning through a comprehensive and integrated approach. Nevertheless, in the past, the integration of CC adaptation into urban planning (UP) and landscape design (LD) was not given adequate consideration by planners and designers due to lack of knowledge regarding CC and the efforts that can be taken to mitigate its effects. The objective of this work is: ? To summarize the current state of knowledge of, and conceptualization of, the core elements of CC impacts and responses in Addis Ababa in terms of their implications for UP and LD in the city; ? To develop a common understanding among urban planners and related professionals of how improvements in UP and LD can contribute to CC adaptation; and ? To mainstream CC in future UP and LD endeavors. The results of this study show that integrating CC adaptation and other response options into UP and LD at the city, subcity/catchment, neighborhood, site/project, and building levels will enhance the sustainability of the city with respect to its resilience to flood risk hazards, water supply during drought periods, and urban heat island effects.  相似文献   
3.
The release and charge-based fractionation of As, Cr, Mo, Sb, Se and V were evaluated in leachates generated from recycled concrete aggregates (RCA) in a laboratory and at a field site. The leachates, covering the pH range 8.4-12.6, were generated from non-carbonated, and artificially and naturally carbonated crushed concrete samples. Comparison between the release of the elements from the non-carbonated and carbonated samples indicated higher solubility of the elements from the latter. The laboratory leaching tests also revealed that the solubility of the elements is low at the “natural pH” of the non-carbonated materials and show enhancement when the pH is decreased. The charge-based fractionation of the elements was determined by ion-exchange solid phase extraction (SPE); it was found that all the target elements predominantly existed as anions in both the laboratory and field leachates. The high fraction of the anionic species of the elements in the leachates from the carbonated RCA materials verified the enhanced solubility of the oxyanionic species of the elements as a result of carbonation. The concentrations of the elements in the leachates and SPE effluents were determined by inductively coupled plasma mass spectrometry (ICP-MS).  相似文献   
4.
Participatory Forest Management in Ethiopia: Learning from Pilot Projects   总被引:2,自引:0,他引:2  
Different arrangements of decentralized forest management have been promoted as alternatives to centralized and top down approaches to halt tropical deforestation and forest degradation. Ethiopia is one of the countries piloting one of these approaches. To inform future programs and projects it is essential to learn from existing pilots and experiences. This paper analyses five of the pilot participatory forest management (PFM) programs undertaken in Ethiopia. The study is based on the Forest User Group (FUG) members’ analyses of the programs using selected outcome variables: forest income, change in forest conditions, forest ownership feelings and effectiveness of FUGs as forest managing institutions. These variables were assessed at three points in time—before the introduction of PFM, during the project implementation and after the projects ended. Data were collected using group discussions, key informant interviews and transect walks through the PFM forests. The results show that in all of the five cases the state of the forest is perceived to have improved with the introduction of PFM, and in four of the cases the improvement was maintained after projects ended. Regulated access to the forests following introduction of PFM was not perceived to have affected forest income negatively. There are, however, serious concerns about the institutional effectiveness of the FUGs after projects ended, and this may affect the success of the PFM approach in the longer term.  相似文献   
5.
Urban water management in Addis Ababa, Ethiopia, is of significant concern to the city government owing to the growing demand for water, poor urban water management practices, insufficient and ineffective infrastructures, and climate change. The objective of this study is to review current water resources and management practices, consider the sustainability of the urban water cycle in relation to climate change, and devise a feasible strategy for a sustainable urban water management system. The results of this study show that the situation as it is now is not sustainable at current levels of demand and supply, either in terms of the systems’ management practices, or in terms of the challenges posed by climate change. An Integrated Urban Water Management strategy that covers the entire urban water cycle, including diversification of water sources, protection and conservation of water, sustainable exploitation, distribution, and consumption and wastewater management, water recycling, nutrient reuse, and safe wastewater disposal, should be implemented as soon as practicable.  相似文献   
6.
Although waste from coffee processing is a valuable resource to make biogas, compost, and nutrient-rich animal food, it is usually dumped into nearby water courses. We carried out water quality assessment at 44 sampling sites along 18 rivers that receive untreated waste from 23 coffee pulping and processing plants in Jimma Zone, Ethiopia. Twenty upstream sampling sites free from coffee waste impact served as control, and 24 downstream sampling sites affected by coffee waste were selected for comparison. Physicochemical and biological results revealed a significant river water quality deterioration as a result of disposing untreated coffee waste into running water courses. During coffee-processing (wet) season, the highest organic load (1,900?mg/l), measured as biochemical oxygen demand, depleted dissolved oxygen (DO) to a level less than 0.01?mg/l, and thus curtailed nitrification. During off season, oxygen started to recuperate and augmented nitrification. The shift from significantly elevated organic load and reduced DO in the wet season to increased nitrate in the off season was found to be the determining factor for the difference in macroinvertebrate community structure as verified by ordination analysis. Macroinvertebrate diversity was significantly reduced in impacted sites during the wet season contrary to the off season. However, there was a significant difference in the ratio of sensitive to pollution-tolerant taxa in the off season, which remained depreciated in the longer term. This study highlights the urgency of research exploring on the feasibility of adopting appropriate pollution abatement technologies to implement ecologically sound coffee-processing systems in coffee-growing regions of Ethiopia.  相似文献   
7.
We have investigated the relevance of the notion of “peripheralism” in the Beles basin. In this lowland border area of Ethiopia, important investments require an evaluation of their socio-economic and ecological impacts in the light of Ethiopia’s Climate-Resilient Green Economy (CRGE) strategy. We contrasted literature of different periods with field observations. In the middle and lower parts of the basin, the Gumuz people traditionally practised shifting cultivation. Resettlement of highlanders is particularly linked to water and land resources. A large irrigation project was initiated in the 1980s, but vegetables and fruits face post-harvest losses. Large water transfers from Lake Tana since 2010 affect the movement of people, the hydrogeomorphology, and ecology of the river. In several parts of the basin, the settlers’ economy now dominates. Many Gumuz became sedentary but maintained their agricultural system, particularly in the south of the lower basin. Land titling allowed allocation of “vacant” areas to transnational or domestic investors. As a result, the semi-natural vegetation is frequently replaced by open cropland, leading to decreased carbon storage and increased soil erosion. This and water abstraction for irrigation jeopardise hydropower production, in contradiction with the CRGE objectives. Despite the recent developments, the contrasts in economic activity make the core-periphery dichotomy to remain actual in the Beles basin. The resettlements and permanent cropping tend to make the upper basin part of the core. However, the installation of a transit road and commercial farms in the lower basin do not allow to consider that a non-peripheral integration has taken place.  相似文献   
8.
Forecast‐based drought early warning/early action has been hampered by both inadequate decision‐making frameworks and a lack of appropriate funding mechanisms. Rural communities in Nicaragua and Ethiopia that have participated in resilience‐building interventions of varying durations demonstrate the value of community‐based actions informed by early warning, forecasts and drought management advice, both before and during the agricultural season. While drought affected all crops negatively, participants were better able to mitigate impacts, were more organised in accessing relief and recovered more effectively. These results are consistent with other research on the cost/benefit of anticipatory actions, use of climate services and appropriate drought management advice. They also confirm the importance of embedding short‐term early action in long‐term resilience‐building. Despite this, formal systems, national and local, remain essentially unimplemented. Systems being developed at global level now need to be operationalised and translated into effective local drought management standard operating procedures for the most vulnerable.  相似文献   
9.
The Environmental Impact Assessment (EIA) was first entered into force in the United States of America in 1969 through the National Environmental Policy Act. Since then, the EIA was implemented in many other countries. In Ethiopia, EIA was formally introduced in 2002 by Proclamation No. 299/2002 after the establishment of the Environmental Protection Authority (EPA) in 1995 and the formulation of the Environmental Policy of Ethiopia (EPE) in 1997. This study, which is based on a document review, interviews, and the application of a survey questionnaire, analyzes the procedures and practices of the Ethiopian EIA system, seeks to clarify fundamental information regarding the EIA system and characteristics of the key elements of EIA processes, and finally, offers suggestions that could improve EIA practices in the country. The overall result of this study shows that Ethiopia adopted EIA procedures that are similar to western models; however, despite approximately 15 years of experience, its implementation is still poor to the point that the use of EIA as an instrument of environmental management could be questioned. The challenges identified by this study include institutional, organizational, and professional capacity gaps, which, in turn, have resulted in constraints ranging from improper screening, scoping, and production of EIA reports to ineffective review, monitoring, and post‐project evaluation. Additional challenges to the system include poor governance and corruption, rapid economic growth, and the mushrooming of micro‐ and small‐scale enterprises that cause pollution and environmental degradation. This article also provides comprehensive suggestions to improve EIA practices in Ethiopia.  相似文献   
10.
The extraction of construction material in Addis Ababa has been a source of public conflict for many years, especially in terms of quarry operation, displacement of people, rehabilitation of quarry sites, and land after‐use. One of the main reasons for the conflict has been the extraction sector's inability to adjust to the existing laws. This paper reports the findings of a study undertaken to assess the environmental and socioeconomic impacts of quarry mining in Addis Ababa, Ethiopia, and it prescribes interventions that can assist in mitigating the negative impacts of mining. Marked operational, environmental, and socioeconomic impacts have occurred as a result of cobblestone quarrying in Addis Ababa. Improvements in the mitigation of these impacts can be achieved if quarrying operations are planned prior to commencement; resource‐efficient and sustainable mining techniques are employed; stakeholder participation is enhanced; the government provides institutional, organizational, and technical support to the operators; regulations are improved and regulatory implementations receive strict follow‐up; and the provision of the Ethiopian constitution's regarding “rights to development” is respected.  相似文献   
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