Integrating climate change adaptation strategies in urban planning and landscape design of Addis Ababa City,Ethiopia

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.     

Urban impact on ecological integrity of nearby rivers in developing countries: the Borkena River in highland Ethiopia

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.     

Traditional occupancy–abundance models are inadequate for zero-inflated ecological count data

Traditional occupancy–abundance and abundance–variance–occupancy models do not take into account zero-inflation, which occurs when sampling rare species or in correlated counts arising from repeated measures. In this paper we propose a novel approach extending occupancy–abundance relationships to zero-inflated count data. This approach involves three steps: (1) selecting distributional assumptions and parsimonious models for the count data, (2) estimating abundance, occupancy and variance parameters as functions of site- and/or time-specific covariates, and (3) modelling the occupancy–abundance relationship using the parameters estimated in step 2. Five count datasets were used for comparing standard Poisson and negative binomial distribution (NBD) occupancy–abundance models. Zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) occupancy–abundance models were introduced for the first time, and these were compared with the Poisson, NBD, He and Gaston's and Wilson and Room's abundance–variance–occupancy models. The percentage of zero counts ranged from 45 to 80% in the datasets analysed. For most of the datasets, the ZINB occupancy–abundance model performed better than the traditional Poisson, NBD and Wilson and Room's model. He and Gaston's model performed better than the ZINB in two out of the five datasets. However, the occupancy predicted by all models increased faster than the observed as density increased resulting in significant mismatch at the highest densities. Limitations of the various models are discussed, and the need for careful choice of count distributions and predictors in estimating abundance and occupancy parameter are indicated.     

Rethinking urban water management in Addis Ababa in the face of climate change: An urgent need to transform from traditional to sustainable system

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.     

The impact of traditional coffee processing on river water quality in Ethiopia and the urgency of adopting sound environmental practices

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.     

Concentrations,bioaccumulation, and health risk assessments of heavy metals in fishes from Nigeria’s freshwater: a general overview

Environmental Science and Pollution Research - Heavy metals (HMs) have attracted global attention due to their toxicity, persistence, and accumulation in aquatic fish in the polluted water...     

Environmentally Sensitive Productivity Analysis of the Canadian Pulp and Paper Industry, 1959-1994: An Input Distance Function Approach

This study employs a parametric input distance function that incorporates both desirable and undesirable outputs to provide a more complete representation of the production technology from which environmentally sensitive productivity and efficiency measures can be generated. This framework also generates pollution abatement cost estimates that are useful for policy making. An input-based Malmquist index of productivity growth that appropriately credits the producer not only for increases in marketable or desirable outputs but also for the production of improved environmental quality through pollution abatement activities is derived from the input distance function. The method was applied to time series data from the Canadian pulp and paper industry. Our shadow price estimates indicate that the marginal cost to producers of pollution control has been rising. The main conclusion of this study is that productivity improvement, from the social viewpoint, has been stronger than conventional measures would suggest.     

Social and Ecological Aspects of Resettlement and Villagization among the Konso of Southwestern Ethiopia

TEKLEMARIAM AYELE²
This is a study of the changing settlement and land use patterns of the Konso in three peasant associations in southwestern Ethiopia and an evaluation of their attitudes toward government-sponsored villagization in the lowlands. Over the years, the Konso have moved spontaneously from the overpopulated highlands toward lower elevations and have recently begun to cultivate on the Yanda plain, but without settling there. Fear of tropical diseases, armed conflict with pastoralists and the Konso perception of lowland living continue to be powerful deterrents to settlement in the lowlands. Major objectives of the government villagization programme are unlikely to be achieved in the Konso area and may instead lead to disaster unless this programme is drastically revised to provide suitable conditions for resettlement and to meet the specific needs of the population.     

Poverty Alleviation and Environmental Restoration Using the Clean Development Mechanism: A Case Study from Humbo,Ethiopia

Poverty, hunger and demand for agricultural land have driven local communities to overexploit forest resources throughout Ethiopia. Forests surrounding the township of Humbo were largely destroyed by the late 1960s. In 2004, World Vision Australia and World Vision Ethiopia identified forestry-based carbon sequestration as a potential means to stimulate community development while engaging in environmental restoration. After two years of consultation, planning and negotiations, the Humbo Community-based Natural Regeneration Project began implementation—the Ethiopian organization’s first carbon sequestration initiative. The Humbo Project assists communities affected by environmental degradation including loss of biodiversity, soil erosion and flooding with an opportunity to benefit from carbon markets while reducing poverty and restoring the local agroecosystem. Involving the regeneration of 2,728 ha of degraded native forests, it brings social, economic and ecological benefits—facilitating adaptation to a changing climate and generating temporary certified emissions reductions (tCERs) under the Clean Development Mechanism. A key feature of the project has been facilitating communities to embrace new techniques and take responsibility for large-scale environmental change, most importantly involving Farmer Managed Natural Regeneration (FMNR). This technique is low-cost, replicable, and provides direct benefits within a short time. Communities were able to harvest fodder and firewood within a year of project initiation and wild fruits and other non-timber forest products within three years. Farmers are using agroforestry for both environmental restoration and income generation. Establishment of user rights and local cooperatives has generated community ownership and enthusiasm for this project—empowering the community to more sustainably manage their communal lands.