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Nech Sar National Park (NSNP) is one of the most important biodiversity centers in Ethiopia. In recent years, a widespread decline of the terrestrial ecosystems has been reported, yet to date there is no comprehensive assessment on degradation across the park. In this study, changes in landcover were analyzed using 30 m spatial resolution Landsat imagery. Interannual variations of normalized difference vegetation index (NDVI) were examined and compared with climatic variables. The result presented seven landcover classes and five of the seven landcover classes (forest, bush/shrubland, wooded grassland, woodland and grassland) were related to natural vegetation and two landcover types (cultivated land and area under encroaching plants) were direct results of anthropogenic alterations of the landscape. The forest, grassland, and wooded grassland are the most threatened habitat types. A considerable area of the grassland has been replaced by encroaching plants, prominently by Dichrostachys cinerea, Acacia mellifera, A. nilotica, A. oerfota, and A. seyal and is greatly affected by expansion of herbaceous plants, most commonly the species of the family Malvaceae which include Abutilon anglosomaliae, A.bidentatum and A.figarianu. Thus, changes in vegetation of NSNP may be attributed to (i) degradation of existing vegetation through deforestation and (ii) replacement of existing vegetation by encroaching plants. While limited in local meteorological station, NDVI analysis indicated that climate related changes did not have major effects on park vegetation degradation, which suggests anthropogenic impacts as a major driver of observed disturbances.

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providing relevant details, so we can investigate your claim. context-specific conceptual, theoretical and empirical foundations is a problem which must be addressed. Drawing on papers from a Special Issue centred on urban green infrastructure and urban ecosystem services in sub-Saharan Africa, we consider what concepts and frameworks are in use and what needs to be considered when framing future research. We also synthesise key messages from the Special Issue and draw together themes to help create a new research agenda for the international research community.

Green infrastructure systems can be selected methodically considering watershed parameters, then the existing urban water network, and surrounding land uses.

Background: Landscape change and disturbance are major challenges of wildlife management worldwide. The purpose of this study is to determine the impacts of anthropogenic landscape disturbances on the abundance and habitat use of terrestrial large mammals of Nech Sar National Park. Disturbance of natural habitats for 1985, 1995, 2005 and 2013 was analyzed using descriptive metrics of different landscapes at the class level. Population estimates of large terrestrial mammals were conducted using the line-transect method. Data were collected on the distribution and abundance of human settlement, domestic animals' sightings and livestock Karel using field observation and Google Earth digital image. Result: The results have shown that anthropogenic disturbances lead to changes in the size, number, distance, spatial distribution and configuration of fragments in the natural habitats between 1985 and 2013. The highest anthropogenic impacts are detected on the forest and grassland habitats through fuelwood and construction wood collection, settlement and overgrazing. Large concentrations of settlement with grass-roofed and tin-roofed houses are observed in the grassland and wooded grassland habitats. Out of the recorded 1079 houses built within the park, 867 (80.4%) were mud and wood wall with grass-roofed and 212 (19.6%) were tin-roofed houses. The ratio of tin-roofed and grass-roofed houses is 0.24:1 which suggests the permanency of human settlement and the high intensity of human impact on the wildlife. About 771 cattle Karels were recorded with the ratio of Karel to house as 0.89:1 which indicates that households have at least one Karel near to their residence. These habitat disturbances have resulted in the decline of key wildlife species in Nech Sar National Park. For instance, the population of Grant's zebra (Equus quagga) has decreased from 6500 in 1985 to 2161 in this study based on the 2013 count. The population of Swayne's hartebeest (Alcelaphus buselaphus swaynei) has significantly decreased in the past decades from 40 in 1992 to 35 in 2008, to 12 in 2010, to four (4) in 2013 and locally extinct between 2017 and 2018 based on the Nech Sar National Park office information. Conclusions: Human activities in the Nech Sar National Park are the root causes for the decline of key wildlife species particularly for the loss of Swayne's hartebeest in the park over the past three decades. These changes are mainly related to habitat loss and habitat fragmentation due to deforestation, livestock overgrazing and residential expansion (tin-roofed, grass-roofed houses). Therefore, the main priority in Nech Sar National Park should be designing management strategies to restore the park as a fully functioning sustainable ecosystem and ensuring the social and economic sustainability of the local community. This intervention can be addressed by creating other means of livelihood,

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 the proportion of informal housing decreased from 57% to 38%. Reflecting the country’s economic prosperity, there was a dramatic increase in the presence of single family housing, particularly on the city’s western side. In 2006, only 1% of residential areas were occupied by high-rise condominiums (4 floors or greater) and this increased to 11% by 2016. The majority of the new, higher density residential developments are located near the eastern edges of the city and this outlying location has significant implications for residents, infrastructure construction, and future development.

The food-water-energy nexus concept helps to produce an integrative solutions to secure the water-related ecosystem services sustainably. This study aims to quantify and map water provisioning and soil erosion regulating services from both demand and supply sides in a spatially explicit manner. It considers the Wabe River catchment of the Omo-Gibe Basin in tropical data-sparse region of East Africa as a case study and uses the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) annual and seasonal water yield and sediment delivery models. The water demands and biophysical parameters data were collected from primary and secondary sources and prepared according to the requirement of the models. The models output were validated after conducting sensitivity analysis of the input parameters. The result shows that the rainfall amount of the catchment is highly seasonal, which causes the surface water to vary according to the seasons. The high annual precipitation and low actual evapotranspiration of the catchment resulted high annual water yields. However, the people in the catchment did not satisfied their domestic water demand as result of inaccessibility and poor management of the rain water. The high net supply of water, especially in the rainy season, carries detached top soil via heavy rainfall in the upper catchment areas. Even though the existing land cover and management practices contribute to sediment retention, a large amount of sediment is exported to rivers, which jeopardizes the food and energy security. Thus, the management of water is essential for enhancing the security of the food-water-energy nexus in the catchment. The methods applied in this study can increase spatial understanding of the water-related ecosystem services especially in data-sparse catchments of the tropics, and lead to improvement of water management to enhance the security nexus.