NEWSLETTER #29 - SOCIETY OF AFRICAN EARTH SCIENTISTS

Volume 7, Issue 3

July-December 2018


CONTENT

Chair's Foreword
The Sustainable Village Model: A Viable Way to Accelerate Development in Rural Africa?
Earth Science Events
References and selected reading


Chair's Foreword*

Welcome of Mr Damola Nadi to SAES Board of Trustees

In this issue we have the great pleasure of announcing the co-option on to the Society of African Earth Scientists Board of Trustees, of Mr Damola Nadi.  Damola is a young agroecologist, who will be an invaluable  addition to our board of trustees, bringing up our number  of personnel to a total of  six. The Society continues to encourage African scientists to join the board, with a special encouragement to prospective members from East Africa, which is not currently regionally represented on the board of trustees.

"Another Africa Is Possible", SAES and AAIP Networking Event and Agroecology Film Show, Thursday 15th November 2018

   In November, SAES hosted a networking event in London entitled  "Another Africa Is Possible" in collaboration with Explo Nani Kofi, the editor of Another Africa Is Possible (AAIP)  Newsletter. It included a presentation on AAIP's grassroots work addressing social justice  and historical issues in Ghana and also Cameroon, which was followed by an agroecology film showing and discussion, featuring the film "Ethiopia Rising: Red Terror to Green revolution".

Aba Hawe from Ethiopia Rising - Red Terror to Green Revolution

   Just shy of 20 people attended the networking event of a social justice organisation (AAIP) with a science organisation (SAES) - an untested and  novel combination which on the one hand introduces scientists to social justice issues, whilst also engaging social justice practitioners in the issues of environmental sustainability, energy, food sovereignty, etc.
   The discussion was notable for suggestions/proposals raised by the audience, including the idea that African and diaspora communities should acquire land on which to put the agroecology techniques learned from the film into practice. The land acquired need only be modest - a garden space, allotment, etc. This was seen as a good means of not only applying and transferring knowledge; but also of engaging youth in productive trans-formative activity, working with nature and with the land.
   The film featured astonishing statistics of achievement by the rural community of Abraha Atsbeha, in the Tigray region of Ethiopia, including moving more soil than the volume of the Great Pyramids,  planting nearly a million trees in 4 years, doubling crop yields, increasing the level of the water table by 15m to such a level as to create a natural spring of freshwater flowing from the ground 24/7, reforesting a previously desertified and barren landscape, terracing many hectares and building numerous check dams, etc. which all in the end helped to increase local water retention and help regenerate the environment.

 
The Sustainable Village Model: A Viable Way to Accelerate African Rural Development?

Imagine a sustainable village model in an African setting: Dwellings which are constructed from locally sourced materials - perhaps the local clay or mud to create mud bricks. There would be sufficient land area to practice traditional African farming, with an emphasis on agroecology. The cleanest freshwater would be collected by rainwater harvesting systems. Advantage would be taken to provide off-grid renewable energy, such as solar and/or wind power, as appropriate. Sanitation could be provided by composting toilets in a sustainable way which transforms harmful human waste into soil, which can be  safely handled and spread over agricultural land as fertilizer.
  The idea is that if one could develop these model villages successfully, it would then merely be a matter of replication to  upscale and reproduce such villages in every country, thereby alleviating poverty in the poorest and most vulnerable rural communities across Africa within a short time frame; as the majority of  the poorest African people live in a rural setting.
   Several initiatives have emerged to trial the idea of the sustainable village; but a number of these are pioneered from outside of the continent, leading to the risks that come with external agency, including  the loss of independence of development.
   Whatever the circumstances in which sustainable villages (SV) are trialed, it is arguably always a positive development, because the benefits for encouraging a development trend or momentum outweigh the dangers. The results of these developments seem positive; although this is tempered  with concern over the problem of upscaling the SV model. Overall, the prevalence of SV model trials all over Africa is a good thing, which can, if managed well by Africa states for the benefit of their citizens, succeed in accelerating African infrastructural Development. The danger when this is managed by external agencies, of diverting the purposefulness of infrastructure away from meeting African needs and towards improving the climate for corporate investors, is palpable, as in the case of the Columbia University Millenium Villages Project that incorporates the usual spectres of  reliance on "improved seeds" and western industrial fertilisers. In such cases, Africa traditional agriculture and agroecology are relegated as "backward", when in fact these approaches guarantee Africa's food sovereignty and environmental sustainability.
   As the first instance of one of these initiatives, the Ecosa Institute [1] created a plan for a sustainable village in Duayee, Liberia that included elements of sustainability mentioned above, among others:-

• Agricultural, food and energy sustainability
• Rainwater harvesting for freshwater
• Paper making and other craft industries

Sustainable Village Model. Duayee, Liberia

   In another instance, Ecovillage articulates the establishment of a Pan-African village development programme aimed at eradicating poverty [2].  The programme aims to accelerate progress by targeting the poorest and most vulnerable  populations which are rural communities. They cite work in Senegal, where the government is committed to establishing 14,000 ecovillages, having established a trial of 45 villages through the Global Ecovillage Network (GEN). They also report on projects in Egypt (Sekem Ecovillage) and Cameroon, where the local NGO, Better World Cameroon, create a sustainable village model with managed soil erosion, water retention, soil enrichment, composting and craft industry.

   Columbia University Earth Institute report in a review of their African Millenium Villages experiment [3], the building of 78 millenium villages in 12 sites across 10 African countries, each representing a major agroecological zone.  In early results the research villages in Kenya, Ethiopia and Malawi have reduced malaria incidence, met calorific requirements, generated crop surpluses, enabled school feeding programmes and provided cash earnings for farm families.

   Lastly, in Rwanda, the partnership of UNEP-UNDP and REMA(Rwanda Environmental Management Authority) resulted in Rwanda's first "green" village [4]. This has been scaled up to provide over 44 sustainable village models to halt environmental degradation, provide renewable energy, livelihoods and improved infrastructure for local people. A cost-benefit analysis revealed that the village at a cost of $636,000 to construct and $22,000 per year to run, the village generated an interest rate of return of 5.8%, 7.7% and 8.9% over 15, 20 and 30 years. Based on these results, the Rwanda government decided to scale up to build 44 villages based on the original model.

   There are many more examples of the sustainable village model in Africa being blueprinted in various countries and it is maintained that this is a positive development. Cabral et al [5] in their review of  the Millenium Village project conclude that such projects at least draw much needed attention to the chronic under-investment in rural areas where the majority of poor people live. A key challenge, they note is for the Millenium Village Project to be integrated into larger African-owned initiatives, such as that of CAADP or NEPAD. How this will happen, they note, still remains unclear.

Earth Science Events

 June 6-7, 2019

Zimbabwe Mineral Resources Conference

VISION: Pro- and preceded by geological field trips. Will be sub-divided into two morning and two afternoon sessions.
VENUE: Harare, Zimbabwe


July 11-13, 2019

World Congress on Geology and Earth Science

VISION: Providing innovative research methodologies for Earth Sciences.
VENUE: London, UK


August 4-9, 2019

70th Annual Meeting of International Society of Electrochemistry

VISION: Linking resources to sustainable development
VENUE:Durban, South Africa


October 6-9, 2019

16th SAGA Biennial Conference and Exhibition
"Current Informing the Future"

VISION: The conference, a staple of the geophysical fraternity in Africa provides a forum for engagement, idea generation and sharing
VENUE: Durban, South Africa

October 6-10, 2019

17th Africa Regional Conference on Soil Mechanics and Geotechnical Engineering
"Innovation and Sustainability in Geotechnics for Developing Africa"


VISION: Innovative and sustainable infrastructure is crucial for Africa's economic integration. As such, the vision of improved geotechnics is a positive notion directed at the development of the continent.
VENUE: Cape Town, South Africa

References and Selected Reading

1. https://www.ecosa.org/model-sustainable-village/
2. https://ecovillage.org/our-work/consultancy/pan-african-ecovillage-development/
3. Sanchez, P., Palm, C., Sachs, J., et al, "The African Millenium Villages", Proceedings of the National Academy of Sciences of the USA, October 23, 2001 104 (43) 16775-16780; https//doi.org/10.1073/pnas.0700423104
4. South-South World, "Sustainable Development Revolution through Rwanda's Green Villages", 30th May 2018.
5. Cabral, L, J. Farringdon, E. Ludi, "The Millenium Village Project - a new approach to ending rural poverty in Africa?", Natural Resource Perspectives 101, August 2006.

*Board of the Society of African Earth Scientists: Dr Enas Ahmed (Egypt), Osmin Callis (Secretary - Guyana/Nigeria), Mathada Humphrey (South Africa), Dr Chukwunyere Kamalu (Chair - Nigeria), Ndivhuwo Cecilia Mukosi (South Africa), Damola Nadi ( Nigeria).

 

NEWSLETTER #28 - SOCIETY OF AFRICAN EARTH SCIENTISTS

Volume 7, Issue 2

April-June 2018


CONTENT
Chair's Foreword
Sustainable Soil Health in Africa
Earth Science Events
References and selected reading


Chair's Foreword*
We address the problem of sustaining healthy soils in Africa, responsible for provision of our food, as well as processing of drinking water, and absorption of carbon and other benefits which help to maintain a healthy human population. We note however, the challenges and threats Africa is facing to maintain its independence of food and seed systems, as  poor soil health  accompanied by widespread food insecurity is being used as justification to introduce high doses of expensive fertiliser into African soils and GM seeds that are put forward as an improvement over traditional seed sharing systems.


Sustainable Soil Health in Africa

In many African societies traditionally the Earth is a feminine and divine nature principle according to which life and society is organised. The living are merely seen as custodians of the Earth, which has ecological implications in terms of the responsibility to preserve the environment for future generations. Furthermore, the Earth was seen as a living being, not just lifeless matter.
   At the end of the 20th century, the Earth Sciences were transformed by a paradigm shift in the way that scientists view the Earth. James Lovelock's Gaian view of our planet, articulated the idea that the Earth, rather than being an inert lump of rock, is actually a living functioning organism [1].
   This view which sees the earth as dynamic and alive has percolated down through the earth sciences, such that today, in soil science, the soil is seen, not as inert matter, but as a living system. Whereas in the case of the living Earth, the new science of physiology of the earth (geo-physiology) was born, so in the case of the soil, we have seen the birth of the science of "soil physiology".
   This new way of viewing the soil has put a new emphasis on the question of soil health and soil quality, which is seen to have certain indicators, five of which are  identified by Rickson [2] as: soil structure, organic material content, water/air infiltration capacity, biota (the animal and plant life of the particular region) and nutrients. Karlen  earlier in 1997 had defined soil health as "..the soil's fitness to support crop growth without becoming degraded or otherwise harming the environment"[3].
   Natasha Gilbert writing in Nature has stated  what most would agree: That the key to tackling hunger in Africa is enriching its soil. "The big debate is about how we do it"[4]. A case study is recounted of Eneless Beyadi who borrows $24 from a European friend to afford the cost of two 50kg bags of chemical fertiliser. But this fertiliser ensures her crop and harvest is significantly more successful than those of her neighbours, who have not been able to afford fertiliser.
   The soil health project of the Alliance for a Green revolution in Africa (AGRA) has identified the net loss of nutrients from soils in many parts of Africa and Gilbert notes "Fertilisers make such a profound difference here because the rusty red soil, as in many parts of Africa, is deficient in organic matter and in key nutrients such as nitrogen and phosphorous" [5]. Over the past 30 years the net loss in these nutrients equates to $4 billion of fertiliser. A clear message from the article on what it proposes is the solution: substantial doses of fertiliser. The AGRA funded study by Martey et al notes that 90% of farmers in Ghana are small holdings of  less than 2 hectares in size, with production being mainly rain-fed. The study made its focus on the factors influencing mineral fertiliser adoption among small holder farmers in northern Ghana , and like other studies proposes the most practical solution to seeing lack of the nutrients nitrogen and phosphorous is high doses of fertiliser [6,7]. The high food insecurity of the study area further convinces the study's authors that increasing the adoption of high fertiliser use among small holder farms is the only solution to enrich the regional soil, despite high costs. AGRA and its scientists and government supporters urge the local adoption of  policy to  subsidise smallholder farm purchases of both fertilisers and GM seeds (usually termed "improved seeds").

                                                                                                                                     Photo:Food and Agriculture Organisation, UN.

   To balance the view of fertiliser being the key to boost soil fertility we have the alternative view taken by the Alliance for Food Sovereignty in Africa (AFSA) and the Food and Agriculture Organisation (FAO) at the UN, pushing for an approach which is agro-ecological and therefore takes into account the conservation of the local ecology; not simply high-yielding seed and fertiliser to promote that seed; but also the environment in which the seed thrives, the health of the soil, the level of groundwater and its freedom of pollution, vegetation, protection against soil degradation,etc. Also pushing for cheaper more organic and sustainable solutions: such as no till farming; mulching, and "fertiliser" plants that boost the soil's nitrogen content organically. According to some reports, these techniques are beginning to raise yields and improve soil fertility.  The promotion of fertiliser trees is currently taking place in at least four countries: Malawi, Niger, Kenya and Rwanda. However, critics complain that farmers are slow to adopt these methods as they require significantly more labour. This is an uneven observation by critics  in so far as the cost to purchase fertiliser or "improved" seeds is surely a much greater obstacle than difficulty of labour. Furthermore, because seeds and fertilizer are often out of range of affordability they encourage falling into debt and dependency ties (through loans) both on a personal and a national level.
   The response of  AGRA (and its agro-business directed research) to nitrogen fixing plants is to simply now fund research into GM crops that have these nitrogen fixing properties bred into them. Ken Giller, an agronomist from the Netherlands, has been given a $22 million grant by the Bill and Melinda Gates Foundation to research a GM nitrogen-fixing legume crop[8]. This looks like  aiming to neo-colonise an African market for nitrogen fixing plants where one has yet to emerge; because companies will eventually patent such plants and farmers will have no choice but to purchase the seed for them. It is in these circumstances we see the need for an organisation such as AFSA to voice legitimate concerns over the motivation of the Bill and Melinda Gates Foundation philanthropy  and its high threat to African food and seed sovereignty[9].
   It is disappointing  to observe that perhaps the whole debate has actually gone backwards in the past 26 years. Back in 1992, FAO in Rome published a report on Soil and Water Conservation in Subsaharan Africa which showed how a variety of traditional practices in soil and water conservation served to increase soil fertility and productiveness. Yields were seen to be 30% higher than those gained with conventional agriculture[10]. This means that agroecological methods have been proven, but  not applied on the ground for the past 26 years. AFSA is helping to redress this situation; holding workshops for African farmers on a pan African level [11].
 

Earth Science Events

  October 11-13, 2018

Towards Sustainable Management of Natural Resources: resources for generations yesterday, today and tommorrow

VISION: Earth sciences week organised by Regional Centre for Environmental and Mining Geological Studies
VENUE: Bukavu, DR Congo


October 24-25, 2018

ISERD, 475th International Conference on Environment and Natural Science

VISION: Scholars, scientists, engineers and students present and share their ongoing research activities with a view to enhancing research relations globally.
VENUE: Cape Town, South Africa.



October 25-29, 2018

The 12th Conference of the African Association of Remote Sensing of the Environment

VISION: A conference focused on earth observation and geospatial science in service of sustainable development goals. Conference themes include 1) Big data and data mining of geospatial data. 2) Climate change implications for sustainable development. 3) Geospatial science for early warning systems for geohazards.4) Influence of African space policy on the youth generation 5) Remote sensing for natural resources management, etc.
VENUE:Alexandria, Egypt.


November 3-5, 2018

African Food Systems and the Strategic Development Goals (SDGs)

VISION: A conference hosted by the Alliance for Food Sovereignty in Africa (AFSA) on the future of food systems in Africa and the launch of a continental campaign,
VENUE: Dakar, Senegal



References and selected reading

1. Lovelock, J., The Ages of Gaia: A Biography of Our Living Earth, Oxford University Press, 1988.
2. Rickson, R.J., presentation "Improving Soil Structure and Reducing Soil Degradation", Managing
    Soils for Profit & Restoration, Cranfield University, 19th January, 2016.
3. Karlen, D. L., M. Mausbach, R. Cline, J. Doren, R. Harris, G. Shuman, Soil Quality: A Concept 
    Definition and Framework for Evaluation, Soil Sci. Soc. of Am. J., Vol. 61, No. 1, p. 4-10,  1997
4. Gilbert, N., Dirt Poor: The key to tackling hunger in Africa is enriching its soil, Nature,  vol.
    483, page 525-7,29 march 2012.
5. Ibid.
6. Martey, E.,Wiredu, A.N., Etwire, P.,Fosu, M., Buah, S., Bidzakin, J., Ahiabor, B., Kusi, F.,
   Fertiliser Adoption and Use Intensity Among Smallholder Farmers in Northern Ghana,
    Sustainable Agric. Res.,Vol. 3, No.1, 2014.
7. Lu, C. and |H. Tian, Global nitrogen and phosphorous fertiliser use for agriculture and production
    in the past century:shifted hotspots and nutrient imbalance, Earth Syst. Sci. Data, 9, 181-192,
    2017.
8. Gilbert, N., Op. Cit.
9. Mayet, Mariam, Dangers of the Gates Foundation: Displacing Seeds and Farmers, Grassroots International, 18th Nov. 2015.
10. Food and Agriculture Organisation, United Nations, Soil and Water Conservation in Subsaharan Africa, Rome, 1992.
11. https://afsafrica.org/african-farmers-receive-training-on-agroecology/

*Board of the Society of African Earth Scientists: Dr Enas Ahmed (Egypt), Osmin Callis (Secretary - Guyana/Nigeria), Mathada Humphrey (South Africa), Ndivhuwo Cecilia Mukosi (South Africa), Dr Chukwunyere Kamalu (Chair - Nigeria).

NEWSLETTER #27 - SOCIETY OF AFRICAN EARTH SCIENTISTS

Volume 7, Issue 1

January-March 2018


CONTENT
Chair's Foreword
Renewable Energy Battery Regulation and Recovery in off-grid PV Systems
Earth Science Events
References and selected reading



Chair's Foreword*
This issue addresses the problem of renewable energy battery life as applied to Africa where batteries are a very expensive  yet very vulnerable component of  off-grid photo-voltaic  (PV) solar electricity energy systems.

Renewable Energy Battery Regulation and Recovery in Off-grid PV Systems

Introduction
The regulation of battery charge when rechargeable batteries are used to store energy drawn from solar panels (or wind or hydro-turbines), is crucial if battery life is to be maximised and this expensive component of the electric system is to be sustained.
   It is worthy of note that there are social as well as environmental issues that impact on the effectiveness and even economic feasibility of this technology. The fear of theft, for instance,  can sometimes restrict options for users in where they feel able to locate solar panels.  Also there may be limitations on roof  space which is not shaded and therefore open to sunlight. The structure of roofing may be such that direct sunlight is only received by the panels  for part of the day. These factors do lead to the battery/battery bank not being fully charged on a regular basis, which is important to sustain battery life.
   Although the price of solar energy is rapidly falling, especially in comparison to fossil fuels, it still remains a prohibitively expensive technology, out of the reach of many of the African population in terms of affordability.   It therefore is of great interest to ascertain if system batteries that become deeply discharged, for one reason or another, can be recovered; saving the relatively unaffordable cost of replacement, as well as the prospective environmental hazard associated with battery disposal.


Basic Considerations in Battery Charging
In a photo-voltaic (PV) electrical energy system with

• a battery /battery bank which stores energy collected from the solar panels (or wind or hydro-turbines)
• a power inverter to convert DC current to AC current for household appliances
• a charge controller to regulate the charging of the battery/battery bank from the solar panels (or other source) so the battery does not become over-charged (which can release toxic gases) or discharged below 80% of its capacity,

the charge controller will cut out the inverter and stop the system working once the battery charge drops to 50%. Contrary to what might be expected, battery charge state is only inversely related to the battery voltage above approximately 21 volts, for a 24 volt battery/battery bank, as the graph below illustrates (figure 1.). At 100% charge the voltage of a 24v battery/battery bank is 25.5 volts. At 90% charge it is 25.24 volts; at 50% it is 24.20 volts; at 10% it is 23.02 volts, and so on.

Figure1. Percentage % Battery Charge Remaining for a 24 volt Battery/Battery Bank

   In a PV system the charge controller would normally prevent the batteries from discharging below  80%  of capacity. However, if the PV system is disconnected for some period, the batteries will slowly discharge in storage and if left without recharging for a considerable period, they will become very deeply discharged. The discharge is more severe if  the battery/battery bank remains  connected to equipment, such as the power inverter, or even the charge controller itself.

   From basic principles, we know that if voltage is applied to the battery system , which is greater than the battery's voltage, a current will flow through the battery (in reverse direction to when it is supplying a current) and will charge. The rate of charge or current that will flow will depend on the difference between the battery voltage and that of the energy source for recharging (e.g., solar panels).

   Common wisdom until recently was that such a battery would be beyond recovery and effectively dead. However, battery techhnology is under the spotlight and there is a view that slow charging with solar panels can recover deeply discharged batteries; which should be welcome news for solar energy system users in the developing world.

  In the following considerations we focus on the lead/acid battery, which would appear to be the most commonly used type of rechargeable battery supporting PV systems in Africa. The lead Acid battery  illustrated in figure 2, consists of positive and negative terminals both made of lead plates. As the battery charges,  the process of electrolysis delivers a layer of lead oxide to the positive terminal; whilst discharging the battery causes the lead dioxide  and lead on  the plates to be  converted to a soft lead sulphate. The reaction dilutes the acid and makes it less dense.

Figure 2. Lead/Acid Battery with positive and negative lead plate  terminals

     

Lead - Acid Battery Regulation and Recovery


Diaz and Egido (2003) in their paper on battery charge regulation [1], make technical recommendations for the charge regulation of lead/acid batteries. They note that batteries are the weakest component in the PV system since they rarely perform at full capacity and often diminish in storage capacity with time. This diminution is mainly due to failure to maintain full charging of the battery, for reasons including

• randomness of solar radiation
• personal consumption pattern of each PV user
• cost and availability
• battery working in limited range due to various factors, limiting the expected long battery life. 

Diaz and Egido discover from their tests, significant variations in  the discharge profiles of batteries depending on the make of charge controller; indicating that choice of controller is an important factor in ensuring the optimum regulation and operation of the battery.

   The authors recommend maximum depths of battery discharge which they say should not be exceeded.

   In practice, circumstances as already described do mean that these depths are often unavoidably exceeded for one reason or another. However, earlier work of  Spier and Kasinkoski (1995) goes to the trouble of testing if deep discharging really does mean the fatality of the battery [2], and not simply accepting the common wisdom, which has not been sufficiently tested. These earlier authors writing in the Journal of Power Sources, posit the crucial and exact question that needs to be answered :

"Can the battery recover from a very deep discharge at a low discharge rate, followed by a slow recharge under PV-type conditions?"[3]  The authors answer this by concluding that in general most batteries can be recovered whilst losing no more than about 10% of their charge capacity, after storage in a deeply discharged condition.

   This result means that we can avoid massive wastage of solar battery resources  provided we are able to recharge in the correct manner. Apparently, many standard battery chargers are not always able to fully recharge deeply discharged batteries, because a safety mechanism  prevents this. However, a safe and  effective method is to follow-up the use of a battery charger with the application of a slow charge via solar panels, which may take days, but will deliver battery charge back to almost full capacity.

Earth Science Events

April 17-19, 2018

The 7th Digital Earth Summit

VISION: In the decades since the coining of the concept of Digital Earth, we have seen technological advances in earth observation, Geographical Information Systems, communication networks, grid computation and other areas of globally oriented digital technology. The International Society of Digital Earth (ISDE) has worked in collaboration with Chouaib Doukkali University, the African Association of Remote Sensing in the environment  and the Moroccan Association of Remote Sensing in the environment to host a conference on Digital Earth for sustainable development that brings together scientists and other professionals from Africa and the international community to present their achievements in research, share expertise and experience.
VENUE: Faculty of Science, Chouaib Douakkali University,
El Jadida, Morocco.


July 14-15, 2018

IASTEM, 420th International Conference on Environment and Natural Science

Lagos, Nigeria.


July 21-28, 2018
27th Colloquium of African Geology and 17th Conference of the Geological Society of Africa
VISION:This is a major biennial meeting organised this year by Aveiro University and Geological Society of Africa, under the auspices of Geological Society of Africa.  The meeting invites senior and early career scientists from all over the globe to participate and  foster international cooperation.
VENUE: Aveiro University, Portugal.

July 22-23, 2018

IASTEM, 425th International Conference on Environment and Natural Science

VISION: Scholars, scientists, engineers and students present and share their ongoing research activities with a view to enhancing research relations globally.
VENUE: Port Luis, Mauritius.

August 30, 2018

IASTEM, 449th International Conference on Environment and Natural Science

VISION: Scholars, scientists, engineers and students present and share their ongoing research activities with a view to enhancing research relations globally.
VENUE: Lagos, Nigeria.

October 24-25, 2018

ISERD, 475th International Conference on Environment and Natural Science

VISION: Scholars, scientists, engineers and students present and share their ongoing research activities with a view to enhancing research relations globally.
VENUE: Cape Town, South Africa.



October 25-29, 2018

The 12th Conference of the African Association of Remote Sensing of the Environment

VISION: A conference focused on earth observation and geospatial science in service of sustainable development goals. Conference themes include 1) Big data and data mining of geospatial data. 2) Climate change implications for sustainable development. 3) Geospatial science for early warning systems for geohazards.4) Influence of African space policy on the youth generation 5) Remote sensing for natural resources management, etc.
VENUE:Alexandria, Egypt.



References and selected reading

1. Diaz, P. and Egido, M.A., Experimental Analysis of Battery Charge Regulation in Photovoltaic Systems, Prog. Photovolt: Res. Appl. 2003; 11:481-493 (DOI: 10.1002/pip.509).
2. Spiers, D.J, and  Rasinkoski, D, Predicting the service lifetime of lead/acid batteries in photovoltaic systems, Journal of Power Sources 53 (1995) 245-253.
3. Ibid., p. 248.

*Board of the Society of African Earth Scientists: Dr Chukwunyere Kamalu (Chair - Nigeria), Ndivhuwo Cecilia Mukosi (South Africa), Osmin Callis (Secretary - Guyana/Nigeria), Mathada Humphrey (South Africa), Dr Enas Ahmed (Egypt).

NEWSLETTER #26 - SOCIETY OF AFRICAN EARTH SCIENTISTS

Volume 6, Issue 4

October -  December 2017

Chair’s Foreward

In this issue we look at the use made in earth science teaching and research of virtual globe applications, in particular,  Google Earth. In 2013 Society of African Earth Scientists (SAES) set a challenge to use Google Earth to measure the land area and coastline of Africa as part of Day of Earth Sciences in Africa (DESA), held on 20-21^st March each year. Five years later it will be interesting to revisit this activity and note if there have been any significant changes in results, particularly if we can note any change occurring in the length of the  African continental coastline in the last half-a-decade.

This year DESA is coinciding with the joint international congress of both the Arab Geosciences Union  and the African Association of Women in the Geosciences, entitled “ Earth Sciences for Society”, and hosted at Chouaib Doukkali University, Morocco, 20-24^th March 2018.

In our publication review, a spotlight is put on soil erosion in Africa, where increasing scarcity of land is leading to farm cultivation on steeper and steeper sloped land, unsuited to farming because of the catastrophic soil erosion that can be brought about when steep slopes are used. On steep slopes, runoff acquires greater velocity and erosive power, to greatly increase soil erosion. We look at how vetiver grass technology can be used to arrest this problem. The science of erosion protection on slopes must guide a judicious use of the right  traditional farming methods on steep slopes, such as stone lines (provided slope steepness is not so steep as for stones or rocks to become   prone to rolling) or terracing, rather than, for instance, a tillage system of soil mounds that only leads to more serious erosion involving soil and nutrient loss. Soil mounds, which are well suited for flat land or gentle slopes, but which worsen erosion on steep slopes (as they encourage runoff concentration and gully erosion) are too often used  on steep slopes by farmers without awareness of the dangers. The need for  education of African farmers about soil and water conservation is therefore seen as essential and even  urgent. 

Collect Earth Mapathon Event in Gatsibo, Rwanda (via Fletcher, K., Woldemariam, T.,  and F. Stolle, "Scientists Use Google Earth and Crowdsourcing to Map Uncharted Forests", World Resources Institute, 2017)

Google Earth and other Satellite Applications as Earth Science Research and Education Tools

Google Earth (GE ) gathers data from various satellites orbiting our planet to gain information from space  on objects observed on the planet surface  to an accuracy as good as 0.5m width (20 inches).

   This time lapsed data can be employed to study our changing  environment including  such related problems as soil erosion, land degradation as well as  deforestation and desertification.

   GE represents a powerful tool with potential  for large savings in on-site survey costs, particularly in the rural areas of developing countries  which might otherwise be inaccessible. It is feasible that in the near future African engineers maintaining the Trans-African Highway will not need to travel to  locations were highways maintenance is needed to assess repair requirements. Rather, they will be able to access the information from virtual time lapsed images of the highway accessible from their office desk, using Google Earth (GE).

   GE is also of value in monitoring deforestation and desertification. According to Fletcher, Woldemariam and Stolle in a paper for the World Resources Institute, it takes huge effort to count the trees in a forest. However, using crowdsourcing scientists have recently been able to count the trees in the worlds drylands making up 40% of the earth’s land surface [1].

A great source of help in this exercise was the use of local people’s knowledge. Fletcher,et al report that this improved the accuracy of the count by about 9%. This is because local people were familiar with the types of vegetation and plant life to be found in the locality and from remote satellite images were able to distinguish for instance a shrub from a tree, or several trees from a forest. This local knowledge was contributed by means of local "mapathons", using google satellite technology to count and to map trees and forests. It enabled imagery from satellite observation to be checked against real data on the ground to ascertain the level of human error, and make the appropriate adjustment.

      Areas of earth science such as hydrology have also seen a great advantage in the use of Google Earth. There is a web-based hydrologic educational system called HydroViz that supports students learning in hydrology or related earth science subjects and serves as a virtual hydrologic observatory. [2]

   There are also papers published proving Google earth to be a potent conservation tool [3]. Many projects on the ground have taken off due to information gathered initially through use of Google earth and then later consolidated in the field. An example is the case of Julian Bayliss from Tanzania who conceived of and helped to lead a project of conservation in Tanzania that led to the discovery of new species, including 3 new species of butterfly and a new member of the poisonous Gabon viper family. The use of Google earth resulted in a virtual discovery that then led to an actual one.

   Google earth now offers the possibility of virtual field trips  for earth science students to any place on the planet. Today many countries are using satellite technology to monitor their environment, and Brazil is at the forefront. It uses the technology to track deforestation as it happens.

   Google Earth is also being used for original research: A study published in the Proceedings of the National Academy of Science recently was based on the analysis of 8,510 cattle spotted in google earth images[4]. Two-thirds of the cattle were found to align themselves with the earth’s magnetic field lines in a north- south direction. Thus the research employed satellite technology to prove a phenomenon that had been in plain sight for hundreds and thousands of years: that large non-migratory animals were affected by the earth’s magnetic field. Previously data had shown that migratory birds, fishes, butterflies and animals were guided by magnetism.

Online Geo-data Collection Activity hosted by Society of African Earth Scientists on 20^th March 2018 as part of Day of Earth Sciences in Africa (DESA)

In 2013 SAES hosted a challenge to measure the coastline and land area of Africa using Google Earth. In 2018 this will be launched again for a second time by  the Society of African Earth Scientists (SAES) on the 20^th – 21^st March. The event will be an on-line geodata collection activity involving the measurement of the length of Africa’s coastline and the area of Africa’s landmass.  All participants are invited to post their results on the SAES facebook page on the 20^th– 21^st March or email their results.

Activity Summary

To measure the area and coastline of Africa’s landmass in square km and km respectively, using Google earth software. Google earth software is downloadable free from the Internet. 

Outcome

The SAES hosted activity 

·         - encourages participants to become  familiar with a potential earth science tool that is freely  available

·         - enables appreciation of the true size of the African continent, until recently unknown.

Detailed Description of the Activity

The Society of African Earth Scientists’ Earth Science Day activity invites us to measure two quantities: the area and the coastline of the African continental landmass. The tool  recommended for this exercise is Google earth. Google earth can be freely downloaded from the internet, and measures distances on the surface of the earth. Google earth allows participants to measure Africa’s coastline very easily; whilst we needed to work harder to get an estimate of area.

    Ideally, we could get a very good estimate of Africa’s area by supposing that the shape of Africa is made up of an array of very thin rectangles of equal width, d, (see fig. 1).  The thinner the width, d, the more accurate is the estimate. Theoretically, if the width d is infinitely small, the estimate is exact [5]

   In practice, it is very time consuming to measure area by making the width, d, so fine as to require the use of many rectangles to fill up the shape of Africa approximately.

A quicker method which still gave an acceptable accuracy within 5% was to approximate the shape of the continent as closely as possible using an arrangement of rectangles and triangles to occupy the space inside the outline as closely as we see fit. We then determined the areas of these rectangles and triangles in the usual way (i.e., the area of a triangle is ½ x base xheight; whilst that of a rectangle is width x length), and we summed all the areas to obtain the estimate of the area of Africa’s landmass.

On-line Data Collection - Exemplary Results, 20^th March 2013

i)      Measurement of the length of the African coastline.

A measurement using Google earth of 26,226 km was obtained (with an error of 0.87% from the true value of 26,000 km). Let us see if the results of the measurements we obtain in 2018 are substantially different.

ii)     Measurement of area of Africa’s landmass.

The exemplary results of measurements made are shown penned into the map of fig. 2 below. Summing up the areas of all the composite rectangles and triangles shown, gave an area of 29,040,169 km² (an error of 3.9% from the true value of 30,221,532 km²). Whereas measurements of area have a level of error too high to enable meaningful comparison of land area now  with land area of 2013; coastal measurements are perhaps sufficiently accurate for these to be meaningfully compared. 

This is an area known to encompass the United States of America, Mexico, China, Japan, India, Iberian Peninsula, and Western Europe including the UK.

Earth Science Publication Review

United nations University Institute for Natural Resources in Africa, UsingVetitver Technology to Control Erosion and Improve Productivity in Slope Farming, Oku, E.E.., Aiyelari, E. A., Asubonteng, K. O.,  Accra, Ghana, 2015.[6]

Of the factors that affect the severity of soil erosion, slope is one of the most prominent. Some researchers have noted that runoff (overland flow of water) becomes a dominant agent of soil erosion on steep slopes [Kamalu 1994, Morgan 1995]. Kamalu has defined a threshold steepness at which runoff becomes the dominant erosive agent over rain-splash, or a combination of runoff and rain-splash. This threshold is thought to be soil specific [7].

   The authors begin by  noting the fact that erosion is responsible for great losses of African soil productivity. This situation is exacerbated by the pressures which force Africans to farm on steeper and steeper slopes [Thurrow& Smith 1998).

   Farming and cultivation on these slopes often leads to severe soil erosion.  This is especially the case where African farmers apply traditional methods suited to flat land on slope farms, leading to more serious erosion.  [Oku, 2011].  It leads us to make the point of the importance of the scientific application of African indigenous farming methods to suit the terrain involved. Instead of using traditional tillage involving earth mounds, which is only appropriate on flat or shallow sloped farms and increases erosion on slopes, we can employ other more suitable systems like stonelines or hedging. Furthermore, we can incorporate these methods with  modern soil and water conservation technologies.

   The need for land to cultivate food means we must find a solution which works with this growing trend for steep slope farming.

   Some governments have tried prescribing maximum slopes on which farming is acceptable: for example 12% in Central Africa and 30% in Ethiopia [Grimshaw and Larisa, 1995]. However,  this cannot be enforced and is ignored by famers in need of land to cultivate.

   We must address the question of what technology we can use to reduce soil erosion on these slope farms, as they become more common.Treatments are most effective when combined with or including  a strategy involving use of vegetation to protect against erosion.

Vetiver grass can be used very effectively to slow the velocity of runoff down the slope and hence significantly lessen erosion. The study in fact establishes that vetiver grass used as a buffer strip is more effective at lessening erosion for closer spacing between grass strips. Vetiver grass strips spaced 5m apart were found to adequately slow down the runoff enough to reduce erosion. The positive outcome therefore, is that food production on steep slopes is entirely possible in a sustainable way where we employ soil protection measures like the application  of vetiver grass strips.

Earth Science Events

20-24 March 2018

Earth Sciences for Society
A joint congress organised by
Arab Geosciences Union, African Association of Women in the Geosciences, African Geoparks Network

Venue: Faculty of Sciences, ChouaibDoukkali University, El Jadida, Morocco
VISION: The "Geodynamics, Geo-education and Geoheritage Research Group" of the Geology Department, Faculty of Sciences, El Jadida (Morocco) in collaboration with the Arabian Geosciences Union (ArabGU), the African Association of Women in Geosciences (AAWG) and the African Geoparks Network (AGN) organize jointly the 2nd Arab GU International Conference (AIC2), the 9th AAWG Conference (CAAWG9) and the 3rd International Conference on Geoparks in Africa and MiddleEast (ICGAME3). This joint congress is hosted by the Faculty of Sciences, Chouaïb Doukkali University, El Jadida (Morocco).

References, Selected Reading, etc

 1.   Fletcher, K., Woldemariam, T., Stolle, F., “Scientists Use Google earth and Crowdsourcing to Map Unchartered Forests”, World Resources Institute, 2017.http://www.wri.org/blog/2017/07/scientists-use-google-and-crowdsourcing-map-uncharted-forests,

2. Habib, E., Yuxin Ma and Douglas Williams,  “Google Earth and Virtual Visualisations in Geoscience Education and Research”.

3. Butler, R., Satellites and Google earth Prove potent Conservation Tool, Yale Environment 360, 26 Mar 2009.

https//e.360.yale.edu/features/satellites_and _google_earth_prove_potent_conservation_tool

4. Begall,S., Cerveny, J., Neef, J., Burda, H.,  Magnetic Alignment in Grazing and Resting Cattle and Deer, Proceedings of the national Academy of Sciencees, 2008 Sep9; 105(36): 13451-5. Doi:10

5. This is  the principle behind  estimation of geometric areas and other quantities in mathematics by means of the operation known as “integration”

6. United nations University institute for Natural Resources in Africa,  Using vetiver technology to to control erosion and improve productivity in slope farming, Oku, E. E., Aiyelari, E. A., Asubonteng, K. O., Accra, Ghana, 2015.
7. Kamalu, C., The effects of slope length and inclination on the separate and combined actions of rainsplash and runoff, in R.J. Rickson (ed.), Conserving Our Soil Resources, selected papers papers from First International Congress of the European Society for Soil Conservation,  Centre for Agriculture and Biosciences International,1994.