Droughts often evolve gradually and cover large areas, and therefore, affect many people and activities. This motivates developing techniques to integrate different satellite observations, to cover large areas, and understand spatial and temporal variability of droughts. In this study, we apply probabilistic techniques to generate satellite derived meteorological, hydrological, and hydro-meteorological drought indices for the world's 156 major river basins covering 2003-2016. The data includes Terrestrial Water Storage (TWS) estimates from the Gravity Recovery And Climate Experiment (GRACE) mission, along with soil moisture, precipitation, and evapotranspiration reanalysis. Different drought characteristics of trends, occurrences, areal-extent, and frequencies corresponding to 3-, 6-, 12-, and 24-month timescales are extracted from these indices. Drought evolution within selected basins of Africa, America, and Asia is interpreted. Canonical Correlation Analysis (CCA) is then applied to find the relationship between global hydrometeorological droughts and satellite derived Sea Surface Temperature (SST) changes. This relationship is then used to extract regions, where droughts and teleconnections are

Nigeria has witnessed diverse flood events in the past years and due to the high level of vulnerability and lack of coping capacity of the people, with the fast occurrence of extreme events resulting from climate change, many lives and properties are at risk of its impacts. This paper reviews the recent past and present efforts in assessing the flood impacts in Nigeria. We concentrate this study on the recent works (methods and results) in assessing flood impacts in the country under basic components of flood risk analysis: The hazards mapping and modeling, exposure and vulnerability assessment, with the aim of suggesting possible urgent needs and further development. Based on our review, we conclude that, there is need to explore more effectively the use of state of the art flood models, which integrates all hydrological processes for more accurate prediction and mapping of flood and its associated risks. Also, as one of the steps to plan for adaptation and mitigation of future flood risk and climate change, there is a serious need of detailed research in the development of regional or national flood damage functions for pre-disaster flood damage estimation. The study also suggests further study on the environmental and health impact of flood in the country.

The significance of air pollution as one of the contemporary issues and accelerating factors that propel climate change in both developed and developing countries cannot be overemphasized. The problem of air pollution has seemingly become intractable with the incessant failure of both global and local environmental policies purportedly emplaced to address its devastating trend, particularly in growing megacities of the world. The devastating effects of the phenomenon are more pronounced in megacities of developing countries than in developed ones. Lagos, as an industrialized, commercialized and an emerging megacity in Nigeria, has been subjected to several predictions of the negative impacts of changing climatic conditions partly caused by ubiquitous air pollution. Efforts at stemming the tide of the increasing challenges of air pollution worldwide has significantly been thwarted by inadequate funding, hence the need to review the literature on the environmental implications of growing air pollution, its contributions to climate change and its negative impacts on the lives and properties of teeming inhabitants of Lagos. A review like this will provide a synthesis of knowledge and information on mitigative and adaptive measures that can be adopted to minimize the impacts of air pollution on the mega city.This study utilizes consciously selected and current literatures on the subject matter and found that Lagos inhabitants have been vulnerable to virtually all forms of damaging effects of climate change majorly propelled by seemingly uncontrollable air pollution. This implies that the situation requires proactive measures, otherwise, avoidable loss of lives and large scale destruction of properties may be inevitable. The paper therefore advocates involvement of all stakeholders in both mitigation and adaptation measures to climate change through enhancement of indigenous knowledge and creation of awareness among citizens about the need to be conscious of their carbon foot prints.

The influence of lineaments, lineament intersections and geology on the groundwater yield of the basement terrain of Ondo State was investigated using optical remote sensing data, Aster DEM, geology, and borehole yield data. Landsat-7 ETM+ and Aster DEM were processed to generate composite lineament map. The study area was traversed by five (5) main lineament populations trending N-S, NE-SW, E-W, ENE-WSW, NNW-SSE. Boreholes sited on lineament exhibited a yield range of between 0.8 and 1.28 l/s with an average yield of 1.04 l/s. Boreholes sited close to lineament gave groundwater yield values of between 0.5 and 1.28 l/s and an average yield of 1 l/s, while boreholes located outside lineament gave groundwater yield range of between 0.2 and 1.26 l/s with an average yield of 0.98 l/s. The investigation of the hydrogeological characteristics of the lithologies by superimposing the yield data showed average yield of 0.98 l/s for migmatite gneiss biotite granite undifferentiated (M), 1.01 l/s for porphyritic granite (OGp), 1.03 l/s for medium-to coarse-grained (OGe), 1.17 l/s for pelitic schist undifferentiated (Su), 1.24 l/s for quartz schist and quartzite (Eq), 1.12 l/s for older granite undifferentiated (OGu), 0.5 l/s for slightly migmatised medium-grained granite-gneiss (gg) and 1.23 l/s for fine-grained flaggy quartzite and schists (Sf). The study concluded that borehole data located on or near lineaments or at intersection of lineaments gave higher yields more than those located before lineaments or outside lineaments, while quartz schist and quartzite exhibited the highest average groundwater yield of all the lithological units.Publisher's note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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