Geology for Global Development

Geohazards

Guest Blog: Could agroforestry do more to protect Rwandans from hazardous landslides?

Megan Jamer is a geoscientist from Canada, and an avid cyclist and explorer. Megan is currently travelling around East Africa on bicycle, taking in some remarkable sites and observing first hand the relationship between geoscience and sustainable development. Today Megan makes her debut on the GfGD blog site, writing on the relationship between agroforestry, landslides, and disaster risk reduction.

Some landslide interventions are hard to miss along Rwanda’s highways. There are gabions, and concrete drainage pathways, kept unclogged by women and men in fluorescent vests. Other strategies are more subtle. Where cassava or bean plots are mixed with banana trees or ringed within a hedge, this may also reduce the damage caused by landslides in this central African nation. Rwandan agroforestry is getting attention. The strategy, which combines trees and crops in the same area, is being used to work towards the 2020 goal of trees covering thirty percent of Rwanda’s total surface area. In 2014, more than half of new seedlings distributed by the government were agroforestry or fruit varieties. Food and land scarcity pressure Rwanda’s slopes, and agroforestry is one way to address the root causes of these shortages, protecting against landslides in the process.

A rural dwelling in the hills of northern Rwanda, excavated into the slope (author’s own).

The Problem of Landslides

At least sixty-seven people were killed last year by landslides and mudslides in the north and west, and in the capital, Kigali. Deadly or not, they cause wide-ranging infrastructure damage, harming public infrastructure and trading patterns, as well as hillside settlements and agriculture. Landslides here disproportionately affect the poor, who pursue subsistence agriculture on steep slopes or live in vulnerable urban areas because they have few alternatives.

In the ‘land of a thousand hills’, slopes are made more vulnerable by rainfall patterns that some say are difficult to manage. In The New Times last year, coffee grower Pierre Munyura said that in western Rwanda“we receive about the same amount of rainfall as ever, but the rain comes in heavier and more destructive bursts.” Rainstorms are considered to be the main trigger of landslides in Rwanda, but human activities prepare the slopes for failure. They are cleared and levelled for walking pathways, homes, latrines, small plots and gardens. Other areas are hollowed out for small-scale mining. The result of these activities is a complex pattern of slope disturbance and deforestation.

Hillside communities cultivate in a manner that reflects traditional knowledge, regulations, and the resources available to them (author’s own)

Similar environmental and human conditions come together on the slopes of Mount Elgon in Uganda, where the causal factors of landslides were investigated. The researchers’ prognosis was bleak: “The growing population density not only increases the risk of damage, but hampers the search for solutions for the landslide problem as well.”  Understanding occurrence is the first step in managing rainfall-induced landslides, says Dave Petley of The Landslide Blog, and here Rwanda has made big strides. Its Ministry of Disaster Management and Refugee Affairs (MIDMAR) published a National Risk Atlas in 2015, an analysis of the earthquakes, landslides, windstorms, droughts and floods that challenge Rwanda’s resiliency. The Atlas inventories hazardous landslides, estimates slope susceptibility, and shows maps of properties that affect landslide incidence, including rainfall, slope angle, ground cover and soil characteristics.

MIDMAR’s analyses estimated that nearly half of Rwanda’s population lives in areas with moderate or high slope susceptibility to landslides. These hazards are commonly small and localized, requiring community action, but “knowledge at the citizen level [about landslides] is still low,” says Dr. Aime Tsinda, a Senior Research Fellow at the Institute of Policy Analysis and Research-Rwanda. Translating information in studies like the National Risk Atlas into local knowledge is a slow process. While it’s underway, communities are motivated to adopt agroforestry because of a hazard they are already familiar with: poor quality soil.

More Trees!

Agroforestry is the ‘intentional integration of trees and shrubs into crop and animal farming systems to create environmental, economic and social benefits’. On cultivated slopes where agroforestry isn’t practiced, small plots drape over them, resembling smooth patchwork blankets. Like blankets, their soils can more easily wash away, creep or slide catastrophically. This is what happened last year, says J.M.V. Senyanzobe, a Forestry Lecturer at the University of Rwanda. “If you observe the concerned areas,” he says, “they were empty of trees, just grasses which are not strong enough to stop the soil from being eroded.”

When trees are cut down their roots decay, eventually rendering them ineffective soil binders. The slopes of Mount Elgon demonstrate the difference. Forested areas lacked evidence of landslides, even when they grew on slope angles and in soil types that contributed to slope instability elsewhere in the study area. Deforestation began as early as 3000 BC in what was Rwanda-Urundi! Reforestation and tree cultivation have been encouraged since the 1930s and it’s working: In 1996, an FAO agroforestry study exclaimed that “photographs taken in Rwanda in the early years of this [twentieth] century show landscapes almost devoid of trees, a stark contrast to the present.

Some Rwandans are motivated to plant because of what the trees themselves offer. Bananas are brewed into beer, coffee trees have been called ‘Rwanda’s Second Sunrise’, and eucalyptus and pine provide construction materials. Other trees are valued for their structure, for example marking plot boundaries. And it’s taken some convincing, but more people are trying out types of agroforestry that plant trees and crops together, in an effort to improve soil quality. There are techniques that do more to increase soil stability. This guide recommends mimicking the plant diversity of a natural forest as much as possible, or to plant tree rows within crops along topographic contours. Within Rwanda, living hedges were found to greatly reduce soil erosion, but landslide prevention wasn’t specifically investigated. Senyanzobe recommends a combination of reforestation between cultivated areas, and agroforestry species within crop areas.  Ultimately, “the sustainable solution is to plant trees as much as possible,” he says.

Outside of agroforestry, is there a way to reduce hazardous landslides in Rwanda? Enforcing rules about how people should excavate slopes or use terracing appropriately is difficult, especially in remote areas. Similarly, mass relocation of vulnerable hillside communities is unrealistic in mainland Africa’s most densely populated country. Large-scale agroforestry interventions, by contrast, are already underway. But because they aren’t undertaken to address landslides specifically, their effectiveness is currently limited.

Pieces of the Puzzle

Speaking to the effectiveness of agroforestry for any goal, “it needs to be implemented with sensitivity to people’s needs, priorities and sociocultural and economic conditions,” says the FAO. It’s not yet clear whether many Rwandans choose tree planting specifically for reducing landslide risk—today, selling the tree’s products or increasing soil fertility are more powerful motivators. If this is how communities prioritise, then agroforestry will be pursued to the extent that those benefits are gained. The damage by landslides may be mitigated, but as a by-product.

Obstacles to agroforestry being used for disaster risk reduction overlap with the challenges of agroforestry in general. One major hurdle in Rwanda is the belief that trees can damage crops by shading them, drying them out, or otherwise competing. Unfortunately this is sometimes true. Avocado trees can harm the crops closest to them. Pine and eucalyptus trees are resilient, but also invasive.

Making the most of agroforestry involves more conversations about the risk—and prevention—of landslides. On the heels of its efforts to understand occurrence of its natural hazards, Rwanda is trying to increase public awareness of landslides in a number of ways. In the official guide to primary school construction, choosing a stable slope location is a ‘must,’ and instructions are given to this end. Public radio broadcasts, disaster committees at the district level, and discussions during monthly community service day (umuganda) on topics including disasters are other examples. Currently, about a quarter of disaster-related spending in Rwanda is directed to prevention and mitigation.

Seedling distribution on National Tree Planting Day looks pretty good, but so does a new home. Recently, several high-risk families were relocated to ‘disaster resilient’ homes in collaboration with UN-HABITAT. Both of these events received media coverage, but were largely treated as separate topics.

The collapsed downslope shoulder of a road in southern Rwanda (author’s own)

These conversations in the media and during umuganda need to continue, but hopefully soon when there’s talk of landslides in Rwanda, trees and agroforestry will be a bigger part of the discussion.

Do trees keep you safer from hazards in your environment? Do you think that any tree planting is a good thing when it comes to landslides, or can it bring mixed results?

GfGD Annual Conference 2017

Since 2013, Geology for Global Development (GfGD) has organised an annual conference exploring the role of geologists in fighting poverty and sustainable development. Each event has gathered 100-150 participants (with >80% being students and early-career geoscientists) to engage with experts from academia, the private sector, the public sector and civil society. Our annual conference is a highlight of the GfGD calendar, and we’re very excited to announce the theme of our next, and 5th, annual conference.

Urbanisation is a development mega-trend, associated with both major challenges but also significant opportunities for delivering the 17 UN Sustainable Development Goals (e.g., SDG 11 – Sustainable Cities and Communities; SDG 6 – Universal Access to Water and Sanitation).

“More than half of the world’s population now live in urban areas. By 2050, that figure will have risen to 6.5 billion people – two-thirds of all humanity. Sustainable development cannot be achieved without significantly transforming the way we build and manage our urban spaces.” [UNDP]

“Cities are hubs for ideas, commerce, culture, science, productivity, social development and much more. At their best, cities have enabled people to advance socially and economically.” [UN]

This conference, aimed at geoscientists at all stages of their careers (from students to experienced professionals), will again seek to draw on the expertise of both geoscience and development professionals working across diverse sectors. We’ll be exploring themes such as the sustainable resourcing of cities and resilient cities, with a particular focus on the Global South.

The 5th GfGD Annual Conference will take place on Friday 3 November, kindly hosted and supported by the Geological Society of London (Burlington House, London). A full programme will be released later this summer, and tickets made available then also. Follow our Facebook and Twitter for further details, and keep an eye on this blog for some additional ‘cities and development’ themed articles.

35th International Geological Congress (Cape Town, South Africa)

35th International Geological Congress (Cape Town, South Africa)

The past few months have been busy with other work, and unfortunately I’ve not been able to post much on here. I’m hoping to get back to regular posts over the coming weeks, starting with a note on GfGD involvement in the 35th International Geological Congress (IGC) in Cape Town later this month. The IGC takes place every four years, and is a flagship event of the International Union of Geological Sciences (IUGS).

The 35th IGC, taking place in Cape Town (South Africa) from 27th August 2016 to 4th September 2016, is an exciting opportunity for geoscientists from around the world to meet, share research and exchange ideas. The event will include sessions on geoscience for society, geoscience in the economy and fundamental geoscience – recognising that there are many interactions between these three themes. This is only the third time in the history of the IGC that it has been held in Africa. In 1929, the event was held in Pretoria (South Africa) and in 1952 the event was held in Algeria. It’s an exciting opportunity for South Africa to profile it’s spectacular geology (including Table Mountain in Cape Town), as well as consider the role of geology in supporting development across sub-Saharan Africa.

Geology for Global Development will be playing an active role in the IGC, our first engagement in this international event. Through a successful application to the IGC geohost funding programme, I will be attending to represent GfGD, deliver a workshop, and contribute to sessions on geoethics, geoeducation and natural hazards.

  1. Workshop: Social Responsibility and Sustainability: Education and PracticeThis one-day workshop, run in collaboration with established mineral development expert Mike Katz, will explore ways to introduce socially responsible programs into university education (and other training programmes). It will also discuss skills for sustainability, and consider practical ways by which they can be nurtured.
  2. Talk and Paper Dissemination: Geology and the Sustainable Development Goals. This talk, part of a symposia on geoethics, will outline the importance of geoscientists contributing to the United Nations Sustainable Development Goals. Read the paper (in press in the IUGS journal Episodes) online here.
  3. Talk and Paper Dissemination: Building Good Foundations. This talk, part of a symposia on geoeducation, will share a paper recently published in the Geological Society of America Special Publication 520 on ‘Building Good Foundations: Equipping geoscientists with the skills to engage in international development’.
  4. Talk and Paper Dissemination: Multi-Hazard Interactions. This talk, part of a symposia on geohazards, will present PhD research on the interactions of natural hazards (read more in this open-access Reviews of Geophysics paper) while also highlighting the Young Scientists Platform on DRR to a geoscience audience.

We’ll aim to get as many resources from these events on our website as soon as possible after the IGC.

As a member of the Geological Society of London External Relations Committee I will also be a part of the UK delegation to the IUGS-IGC Council Meetings, examining the work of IUGS initiatives such as Resourcing Future Generations, and groups working on Geoscience Education, Training and Technology Transfer, and Global Geoscience Professionalism.

Where possible I’ll be tweeting from the event (@Geo_Dev and/or @JoelCGill), and sharing more about relevant sessions and events on the blog after I return. If any of our readers will also be attending, and would like to talk more about geology and international development, the UN Sustainable Development Goals, or other relevant geo-topics then please do get in touch.

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