Groundwater storage in Africa

2017 ◽  
Author(s):  
Gabin Archambault

This 5 km resolution grid presents groundwater storage in Africa (in mm). This parameter was estimated by combining the saturated aquifer thickness and effective porosity of aquifers across Africa. For each aquifer flow/storage type an effective porosity range was assigned based on a series of studies across Africa and surrogates in other parts of the world. Groundwater storage is given in millimeters. Detailed description of the methodology, and a full list of data sources used to develop the layer can be found in the peer-reviewed paper available here: http://iopscience.iop.org/article/10.1088/1748-9326/7/2/024009/pdf The raster and a high resolution PDF file are available for download on the website of British Geological Survey (BGS): http://www.bgs.ac.uk/research/groundwater/international/africanGroundwater/mapsDownload.html Groundwater Storage

2017 ◽  
Author(s):  
Gabin Archambault

This 1 km resolution grid shows the estimated mean annual groundwater storage change (in cm) across the aquifer based on annual groundwater-level change and specific yield. Methodology and a full list of data sources used can be found in the peer-reviewed paper: https://www.nature.com/articles/ngeo2791.epdf?author_access_token=_2Z_fJZxRkSVmgVJ7xHTVdRgN0jAjWel9jnR3ZoTv0O07GfIlzqIVm44UgFPb1r62_FUJLao4zkJSzYpv-4gIWJorRXEpgh4iarB8vlRNY_tGV_18CAf2j-_GnADYbdp The raster and a high resolution PDF file are available for download on the website of British Geological Survey (BGS): http://www.bgs.ac.uk/research/groundwater/international/SEAsiaGroundwater/mapsDownload.html Abstraction Groundwater Storage


2017 ◽  
Author(s):  
Gabin Archambault

This 1 km resolution grid shows the estimated mean annual groundwater abstraction in millimeters across the Indo-Gangetic basin based on data from 2010. Methodology and a full list of data sources used can be found in the peer-reviewed paper: https://www.nature.com/articles/ngeo2791.epdf?author_access_token=_2Z_fJZxRkSVmgVJ7xHTVdRgN0jAjWel9jnR3ZoTv0O07GfIlzqIVm44UgFPb1r62_FUJLao4zkJSzYpv-4gIWJorRXEpgh4iarB8vlRNY_tGV_18CAf2j-_GnADYbdp The raster and a high resolution PDF file are available for download on the website of British Geological Survey (BGS): http://www.bgs.ac.uk/research/groundwater/international/SEAsiaGroundwater/mapsDownload.html Abstraction Groundwater Stress


2017 ◽  
Author(s):  
Gabin Archambault

This 5 km resolution grid indicates what borehole yields (in l/s) can reasonably be expected in different hydrogeological units. The ranges indicate the approximate interquartile range of the yield of boreholes that have been sited and drilled using appropriate techniques. Groundwater productivity is given in liters per second. Detailed description of the methodology, and a full list of data sources used to develop the layer can be found in the peer-reviewed paper available here: http://iopscience.iop.org/article/10.1088/1748-9326/7/2/024009/pdf The raster and a high resolution PDF file are available for download on the website of British Geological Survey (BGS): http://www.bgs.ac.uk/research/groundwater/international/africanGroundwater/mapsDownload.html Groundwater Supply


2017 ◽  
Author(s):  
Gabin Archambault

This 1 km resolution grid shows salinity measured as total dissolved solids (TDS, in mg/l) in the groundwater across the Indo-Gangetic basin. Methodology and a full list of data sources used can be found in the peer-reviewed paper: https://www.nature.com/articles/ngeo2791.epdf?author_access_token=_2Z_fJZxRkSVmgVJ7xHTVdRgN0jAjWel9jnR3ZoTv0O07GfIlzqIVm44UgFPb1r62_FUJLao4zkJSzYpv-4gIWJorRXEpgh4iarB8vlRNY_tGV_18CAf2j-_GnADYbdp The raster and a high resolution PDF file are available for download on the website of British Geological Survey (BGS): http://www.bgs.ac.uk/research/groundwater/international/SEAsiaGroundwater/mapsDownload.html Groundwater Quality


2017 ◽  
Author(s):  
Gabin Archambault

This 1 km resolution grid shows mean annual change in water-table levels across the aquifer during the period 2000 to 2010 in meters per year. Methodology and a full list of data sources used can be found in the peer-reviewed paper: https://www.nature.com/articles/ngeo2791.epdf?author_access_token=_2Z_fJZxRkSVmgVJ7xHTVdRgN0jAjWel9jnR3ZoTv0O07GfIlzqIVm44UgFPb1r62_FUJLao4zkJSzYpv-4gIWJorRXEpgh4iarB8vlRNY_tGV_18CAf2j-_GnADYbdp The raster and a high resolution PDF file are available for download on the website of British Geological Survey (BGS): http://www.bgs.ac.uk/research/groundwater/international/SEAsiaGroundwater/mapsDownload.html Abstraction Groundwater Stress


2021 ◽  
Author(s):  
Marsha Allen ◽  
David Boutt

<p><strong> </strong></p><p>Access to fresh water is a critical humanitarian issue in many regions of the world and on the most important sustainable development goals. This crisis is exacerbated by the effects of climate change, pollutants, increases in demand and overuse. Fractured rock aquifers have been providing potable groundwater for many regions of the world, but there still many unknowns about the storage capacity, transit times and flow paths under changing climate scenarios. In this on-going study we aim to understand the magnitude of groundwater storage and Inter-basin flow for water supply development and sustainable use on the island of Tobago, WI. Samples of springs, surface water and production wells were analyzed for the stable isotopes of water (H<sub>2</sub>O) and strontium (Sr), tritium(<sup>3</sup>H) and sulfur hexafluoride (SF<sub>6</sub>). The stable isotopes of water δD<sub>vsmow</sub> and δ<sup>18</sup>O<sub>vsmow</sub> indicates that the groundwater in the northern region of the island is not hydrologically connected to the groundwater to the south because of their distinct D-excess signature.</p><p><sup>87</sup>Sr/<sup>86</sup>Sr and Na-normalized strontium concentrations produces five possible mixing lines which radially increase from the lowest based value of <sup>87</sup>Sr/<sup>86</sup>Sr ~ 0.70396 and Na/Sr (mg/L) ~0.00652. In detail, the maximum values of each line represent: extremes in Na concentration <sup>87</sup>Sr/<sup>86</sup>Sr 0.70576 and Sr/Na 0.0008 mg/L, the groundwater to seawater mixing line<sup>87</sup>Sr/<sup>86</sup>Sr 0.70506 and Sr/Na 0.0023 mg/L, the precipitation to rock equilibration mixing line <sup>87</sup>Sr/<sup>86</sup>Sr 0.70506 and Sr/Na 0.0023 mg/L, water located in silicate rocks to carbonate rocks mixing <sup>87</sup>Sr/<sup>86</sup>Sr 0.70871 and Sr/Na 0.0085 mg/L, and wells that were once affected by seawater intrusion <sup>87</sup>Sr/<sup>86</sup>Sr 0.70563 and Sr/Na 0.0692 mg/L.</p><p>Tritium results range from 0.02 to 0.60 TU and calculations suggest that wells contain a range of 2 to 44% modern groundwater. When compared to other islands at similar latitudinal locations, Tobago’s groundwater presents the lowest mean and median tritium values even though it is the closest to the equator. Basin flux and effective porosity were calculated for the 10 wells using the apparent age obtained from these results under the assumption of piston flow. It was found that all watershed volumes were magnitudes of orders larger than the sub-basins where the wells were located ranging between 0.09 km<sup>3 </sup>to 8.23 km<sup>3</sup>. Basin Flux and effective porosity also contain large range differences 1.40 *10<sup>5</sup> m<sup>3</sup>/yr to 9.93 *10<sup>6 </sup>m<sup>3</sup>/yr, and 0.014 to 0.094, respectively.</p><p>This results also suggest that the groundwater in the southern regions of the island contains the oldest water with one well sample >60 years. SF<sub>6 </sub>results reflect similar ages except for 3 wells samples which are suspected to be contaminated by excess air. This novel discovery illustrates that small, fractured rock island aquifers can possess structural complexities that lead to older groundwater ages and variances in basin characteristics.</p><p> </p>


2018 ◽  
Vol 12 ◽  
pp. 85-98
Author(s):  
Bojan Kostadinov ◽  
Mile Jovanov ◽  
Emil STANKOV

Data collection and machine learning are changing the world. Whether it is medicine, sports or education, companies and institutions are investing a lot of time and money in systems that gather, process and analyse data. Likewise, to improve competitiveness, a lot of countries are making changes to their educational policy by supporting STEM disciplines. Therefore, it’s important to put effort into using various data sources to help students succeed in STEM. In this paper, we present a platform that can analyse student’s activity on various contest and e-learning systems, combine and process the data, and then present it in various ways that are easy to understand. This in turn enables teachers and organizers to recognize talented and hardworking students, identify issues, and/or motivate students to practice and work on areas where they’re weaker.


2011 ◽  
Vol 6 (3) ◽  
Author(s):  
C. E. Hidaka ◽  
H. R. Kolar ◽  
R. P. Williams ◽  
P. G. Hartswick ◽  
S. B. Foong

In many parts of the world, management of water resources and infrastructures is fragmented between agencies at multiple levels – state, provincial, and local – and sometimes between functions within individual agencies. Consequently it is often impossible to take a holistic view of the issues at hand to enable effective management of the resource or infrastructure – either because of the overhead of managing the coordination required, and/or because of politics between the different stakeholders. In their work for IBM, the authors created a concept of an information technology (IT)-enabled “collaboration platform” that integrates different water data sources with IT tools to enable multiple entities to maintain and share a “common operating picture.” This greatly assists with coordination and reduces politics to manageable levels. In this paper, the authors describe the collaboration platform and its benefits by reference to examples of such platforms in use, and propose a reference technical architecture for creating collaboration platforms.


Epidemiologia ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 315-324
Author(s):  
Juan M. Banda ◽  
Ramya Tekumalla ◽  
Guanyu Wang ◽  
Jingyuan Yu ◽  
Tuo Liu ◽  
...  

As the COVID-19 pandemic continues to spread worldwide, an unprecedented amount of open data is being generated for medical, genetics, and epidemiological research. The unparalleled rate at which many research groups around the world are releasing data and publications on the ongoing pandemic is allowing other scientists to learn from local experiences and data generated on the front lines of the COVID-19 pandemic. However, there is a need to integrate additional data sources that map and measure the role of social dynamics of such a unique worldwide event in biomedical, biological, and epidemiological analyses. For this purpose, we present a large-scale curated dataset of over 1.12 billion tweets, growing daily, related to COVID-19 chatter generated from 1 January 2020 to 27 June 2021 at the time of writing. This data source provides a freely available additional data source for researchers worldwide to conduct a wide and diverse number of research projects, such as epidemiological analyses, emotional and mental responses to social distancing measures, the identification of sources of misinformation, stratified measurement of sentiment towards the pandemic in near real time, among many others.


Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 37
Author(s):  
Martial Amou ◽  
Amatus Gyilbag ◽  
Tsedale Demelash ◽  
Yinlong Xu

As global temperatures continue to rise unabated, episodes of heat-related catastrophes across the world have intensified. In Kenya, heatwave phenomena and their associated impacts are ignored and neglected due to several reasons, including unreliable and inconsistent weather datasets and heatwave detection metrics. Based on CHIRTS satellite infrared estimates and station blended temperature, this study investigated the spatiotemporal distribution of the heatwave events over Kenya during 1987–2016 using the Heatwave Magnitude Index daily (HWMId). The results showed that contrary to the absence of heatwave records in official national and international disaster database about Kenya, the country experienced heatwaves ranging from less severe (normal) to deadly (super-extreme) between 1987 and 2016. The most affected areas were located in the eastern parts of the country, especially in Garissa and Tana River, and in the west-northern side around the upper side of Turkana county. It was also found that the recent years’ heatwaves were more severe in magnitude, duration, and spatial extent. The highest magnitude of the heatwaves was recorded in 2015 (HWMId = 22.64) while the average over the reference period is around 6. CHIRTS and HWMId were able to reveal and capture most critical heatwave events over the study period. Therefore, they could be used respectively as data source and detection metrics, for heatwaves disaster emergency warning over short period as well as for long-term projection to provide insight for adaptation strategies.


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