Seismic related natural hazard would be a major disaster as a result of the recent development and planning of new reservoirs, road networks, and the establishment of new urban settlements in previously uninhabited areas. Producing seismic hazard sensitivity maps could provide very fundamental knowledge to understand the probable occurrence of disasters in a seismic prone area. The aim of this paper was to produce seismic hazard sensitivity maps by integrating the Analytical Hierarchy Process (AHP) and the differential interferometric Synthetic Aperture Radar (DInSAR) methods. For the AHP method, six parameters have been generated and evaluated, such as distance from the fault, Lineament density, Lithology, Soil texture, Proximity of historical earthquake epicenters, and slope. The result of the sensitivity mapping showed that 8% (561.51 km2) of the study area was low-risk, 53% (3801.99 km2) medium, 35 per cent (2526.04 km2) high and 2% (142.82 km2) very high. On the other hand, SLC products from Sentinel-1A data sets were analyzed using a six-month interval master and slave image co-registration using the DInSAR method. A mean annual vertical displacement map showing max subsidence of 9.8 mm/year and uplift of 1.7 mm/year was obtained after processing. The acceptability and accuracy of the resulting seismic hazard sensitivity maps was cross-validated using the Receiver Operating Characteristics (ROC) curve. Validation results showed a strong predictive value with an AUC of 0.848. Therefore, output maps will assist policy and decision makers in identifying natural disaster-prone areas.

Wetlands are one of the world’s most important ecosystems threatened by man. This investigation explores the use of Landsat TM and OLI imageries with SRTM DEM for mapping them. Mapping and monitoring of wetlands is done with 86.66% accuracy. As a result, a loss of 21,400 ha yr−1 could be noted. Due to this, differences were also found in the water quality and groundwater level between the degraded and un-degraded areas. As most rivers within the watershed punctuated from the wetlands, their existence was determined based on the hydrological function. Wetland degradation occurred mainly due to climate and agricultural changes over time. Thus, geospatial techniques employed in the present study have proved very useful in simplification and visualization of wetland monitoring.

Land surface temperature (LST) is the burning issue in the world since it affects climate and environment at local, regional and global level. Mainly it resulted from urbanization and its associated extreme Land-use and Land-cover (LULC) changes. Therefore, monitoring of LULC alteration is a significant component in examining of LST variation and applying sustainable mitigation measures. The research has the objective to analyze the spatial-temporal patterns of LST and its variation with LULC composition in Bahir Dar city and its surrounding from 1987 to 2017 with fifteen-year intervals using Landsat images. Image preprocessing was done to retrieve NDVI, NDBI, LST and LULC, and urban-rural gradient analysis and LST Intensity (LSTI) were computed. As the result shows that urban areas of Bahir Dar city rapidly expanded since 1987. The mean LST values increased to 34.5 °C in 1987 to 37.57 °C in 2002 and decreased to 34.57 °C in 2017. Paved surface and agricultural land exhibited higher LST values whereas waterbody and vegetation experienced lower LST. The result also shows that LST has a positive relationship with NDBI (1987: R2 = 0.51; 2002: R2 = 0.48; and 2017: R2 = 0.4) and negative relationship with NDVI (1987: R2 = 0.24; 2002: R2 = 0.25; and 2017: R2 = 0.33). The LST increased towards sub-urban areas and LSTI was higher in the distance between 4 and 10 km. The results of this study are significant for urban planners to implement sustainable LST mitigation strategies and create a conducive living environment in Bahir Dar city.

Examining the spatial variation of surface temperature is an important criterion to create livable urban environment. To examine the cause of heat island variation in the study area located within the rift zones, an algorithm that was prepared for Landsat 8 band 10 were used by taking the Normalized Difference Vegetation Index threshold method for the estimation of ground emissivity by integrating with the result obtained from MODIS night time data. The LU/LC (land use land cover) maps of the area were prepared with better accuracy using on screen classification technique. The derived LST showed that the surface temperature of the city ranges from 20.6 to 41.30 °C and the minimum temperature of the area was observed within the lake and the surrounding areas such as wetland. The maximum temperature was registered on the scattered hills and excavation areas and some parts of bare lands including industrial park of the city. The spatial variation of LST (Land Surface Temperature) in the city is the result of three major factors namely: (1) volcanic products of the geological setting, (2) the nature of the rock (high reflectance) and (3) the LU/LC type. Increasing of evergreen tree cover and rehabilitation of existing mining areas are among the recommended strategy to mitigate the UHI (urban heat island) effects in the city. For future studies in areas that are susceptible to natural heat sources, the satellite data should have high spatial resolution and derived from multiple sensors and satellites that can provide better tools to understand the UHI effect considering the geological setting of the area.

The geographic heterogeneities in lava composition observed in continental flood basalt provinces could provide a probe of material upwelling from the deep mantle and their length scales, but their utility is limited by uncertainties in the locus of magmatism. We examine the magma plumbing system for the Oligocene Ethiopian flood basalts. The province, which exhibits domains defined by the eruption of low-Ti (LT) and high-Ti (HT) lavas, requires a magmatic plumbing system that facilitates the transit of compositionally distinct magmas through the crust without mixing. Here we present a geochemical and geochronological study of a suite of 43 dikes from western Ethiopia. We find that the dikes were dominantly emplaced contemporaneously with the Oligocene flood basalt phase of activity. The composition of the dikes is overwhelmingly LT in character, typified by an overall flat rare earth element pattern (median value of La/Lu-CN=2.6), and a lack of enrichment in incompatible trace elements in comparison to the HT lavas. These observations confirm the western Ethiopian dike swarm as a source for the LT flood basalts in the Ethiopian flood basalt province. We also present tentative evidence for an eastward migration in the LT dike system over time. These observations are consistent with the terminal stages of the LT magmatism being centered on the Simien shield volcano. We conclude that the apparent separation of similar to 400km between the LT and HT magma plumbing systems allowed for the development of a strongly geochemically zoned continental flood basalt province.

The Cenozoic history of the western Ogaden region of Ethiopia, between the Ethiopian rift and the South Afar margin, is marked by uplift and incision of the Ogaden plateau down to the Gorrahei Formation, an upper Cretaceous evaporite formation. Debuttressing of this and the overlying sedimentary formations resulted in widespread and spectacular gravitational spreading landforms over a minimum surface area of 15,000km2, most of which remains unstudied. After clearing up some misconceptions about the surface geology of the study area, the Kebenawa Ridge in the Audo Range, observations are reported that point to a tectonic style controlled by halokinesis and subsequently, gravitational spreading. The role of diapirism and karstification in the observed halokinesis is discussed, as well as the influence of halokinesis on gravitational spreading. Spreading is in part akin to sackung, in that ridge deformation features include a crestal graben and basal ridge topography extrusion, and deformation was triggered by lateral ridge debuttressing. Ridge spreading also presents analogy with gravitational spreading of the Canyonlands grabens in the Needles District, Canyonlands National Park, Utah. The scale and the mechanisms are found to be basically similar, but two differences are noted. First, incision by the drainage network in response to plateau uplift in Ethiopia has debuttressed the topography along two parallel rivers, instead of a single river (the Colorado River) in Utah. Secondly, incision proceeded to the base of the evaporite layer in the Ogaden, whereas incision has not exceeded the top of the evaporite layer in Utah. These differences may have influenced the details of the spreading mechanisms in ways that remain to be investigated. Overall, in Ethiopia, association of halokinesis and a transitional mode of gravitational spreading at the interface between narrow ridge spreading (sackung) and plateau spreading (Canyonlands-type), illustrates a fascinating and unusual ridge evolution style.

The Coupled Routing and Excess STorage model (CREST, jointly developed by the University of Oklahoma and NASA SERVIR) is a distributed hydrological model developed to simulate the spatial and temporal variation of land surface, and subsurface water fluxes and storages by cell-to-cell simulation. CREST's distinguishing characteristics include: (1) distributed rainfall-runoff generation and cell-to-cell routing; (2) coupled runoff generation and routing via three feedback mechanisms; and (3) representation of sub-grid cell variability of soil moisture storage capacity and sub-grid cell routing (via linear reservoirs). The coupling between the runoff generation and routing mechanisms allows detailed and realistic treatment of hydrological variables such as soil moisture. Furthermore, the representation of soil moisture variability and routing processes at the sub-grid scale enables the CREST model to be readily scalable to multi-scale modelling research. This paper presents the model development and demonstrates its applicability for a case study in the Nzoia basin located in Lake Victoria, Africa.

SERVIR is a regional visualization and monitoring system that applies earth observations and predictive models to support decision-making in a range of application areas. For disaster management, SERVIR is developing a costeffective approach for flood prediction, which will be of particular value in undergauged regions. The Goddard Space Flight Center (GSFC) Global Hazard Model – Flood (GHM- Flood) is used, which uses as input data, the TRMM-based Multisatellite Precipitation Analysis (TMPA) precipitation product- TRMM 3B-42, the AMSR-E soil moisture product, the digital elevation data from the Digital elevation from SRTM mission (30m), the MODIS Land cover and evapotranspiration data products, and soil parameters provided by FAO. The Model is taking advantage of the virtually uninterrupted supply of satellite-based rainfall information as an alternative and supplement to ground-based observations. SERVIR is also using near real-time MODIS imagery for semi-automated post event flood mapping. The development and dissemination of these flood products relies upon SERVIR’s geospatial platform, which integrates components for data discovery, acquisition, use, and sharing. The web-based geoportal provides a searchable and viewable as one-stop shop for earth observation data and products, geospatial services, visualization tools, and reports. This effort builds upon the strengths of the Regional Center for Mapping of Resource for Development in Nairobi, with the goal of maintaining a flexible system for use by scientists, educators, and policy makers.

SERVIR-Africa is an ambitious regional visualization and monitoring system that integrates remotely sensed data with predictive models and field-based data to monitor ecological processes and respond to natural disasters. It aims addressing societal benefits including floods and turning data into actionable information for decision-makers. Floods are exogenous disasters that affect many parts of Africa, probably second only to drought in terms of social-economic losses. This paper looks at SERVIR-Africa's approach to floods disaster management through establishment of an integrated platform, floods prediction models, post-event flood mapping and monitoring as well as flood maps dissemination in support of flood disaster management.

Lake Victoria, the second largest fresh water lake in the Eastern part of Africa is a vital natural resource for the economic well being and prosperity of over 30 million people located in riparian regions of Uganda, Kenya and Tanzania. It covers a large area of about 68,870 km2 and produces a GDP of about US $30 billion per year. The region is also very much prone to natural disasters such as severe floods during heavy precipitation periods in the Eastern part of Africa. In addition to floods, the precipitation also produces large infestations of mosquito larvae due to the standing water in many areas. This further causes multiple vector borne diseases such as Malaria, Rift Valley Fever and more. These problems are of serious concern and require active and aggressive surveillance and management to minimize the loss of human and animal lives and property damage. Satellite imagery and observations along with the in situ measurements provide a great tool to analyze and study this area and inform the policy makers to make calculated policy decisions which are beneficial to the environment. Recently, NASA and USAID have joined forces with the Regional Center for Mapping of Resources for Development (RCMRD) located in Nairobi, Kenya to utilize multiple NASA sensors such as TRMM, SRTM and MODIS to develop flood potential maps for the Lake Victoria Basin. The idea is to generate a flood forecasts and remote sensing data has proven extremely valuable for identifying the location, extent, and severity of these events. However, despite extraordinary efforts on the part of remote sensing data providers to rapidly deliver such maps, there is typically a delay of several days or even weeks from the onset of flooding until such maps are available to the disaster management community. This paper summarizes efforts at NASA to address this problem through development of an integrated and automated process of a) flood detection b) flood forecasting, c) satellite data acqui- - sition, d) rapid flood mapping and distribution, and e) validation of flood forecasting and detection products.

Unfortunately, the name of author Daniel Irwin was misspelled as Daniel Irwn in the original publication. We hereby correct this.

We use model experiments to address the dynamics of magma upwelling during incipient break up of the continental lithosphere. In particular we study the emplacement mechanisms responsible for formation of Continental Flood Basalts. The models show that the dynamics of melt upwelling and distribution and the surface topography are all sensitive to the boundary conditions and the rheological stratification. When melt is involved, there is no or little stretching at break-up time of the continental lithosphere. Depending on the boundary conditions, zones of reduced strength and soft magma pockets localize strain and create focussed or segmented zones of significant weakening and fracturing. When extension of the lithosphere is fast and steady, magmatism is segmented in spaced fissures. In contrast, when extension is slow or episodic, focussing of magmatism and fracturing is the preferred mode of melt emplacement. Upon fracturing of the brittle layer, the melt extrudes to the surface as lava flows. Buoyancy is the dominant mechanism by which magma is transported in the ductile lower crust and upper mantle. In contrast, dykes provide the means by which basaltic melts migrate through the brittle part of the lithosphere. Such spectacular intrusions are likely to have fed Continental Flood Basalts. The model results show that buoyant rise and focusing of magma, originating from a plume or a lithospheric source undergoing slow and/or episodic extension might provide a mechanical explanation for the profuse volcanism of Continental Flood Basalts, at break up time of the continental lithosphere e.g. the Ethiopian Trap Basalts. The models provide new prospects on magma dynamics and lithosphere–mantle interactions.