Climate Change and Resilient Housing: Lessons for Mozambique

Cyclones Idai and Kenneth earlier this year had devastating effects in Mozambique, Zimbabwe and Malawi. More than US$4 billion was needed to help the countries recover, rehabilitate and reconstruct.[1]

Mozambique ranks third among African countries for exposure to risks from climate variability, behind Tanzania and Lagos.[2] Given the proximity of some of its cities to low-lying coastal areas, it was inevitably hit the hardest by Cyclones Idai and Kenneth. Power and communications networks failed, homes and livelihoods were destroyed, hectares of crops flooded, and infrastructure destructed – severely affecting communities living in these pockets of Mozambique.

These cyclones are increasingly viewed as a consequence of climate change.[3] They are making average temperatures and weather patterns more unpredictable, resulting in droughts, heavy rains and storm surges, floods, rising sea levels, heat waves, wildfires and excessive strong winds – leaving in their path a wave of destruction with economic, social and environmental losses, and even the loss of lives.

Africa has been identified as the continent most vulnerable to these impacts. The Climate Change Vulnerability Index for 2017 finds seven of the 10 countries most at risk from climate change are on the continent.[4] More than 2 000 natural disasters have hit Africa since 1970, affecting 500 million people and killing almost a million.[5] Temperatures are increasing faster than the global average. In a sample of 30 African countries, two-thirds are warming faster than the world as a whole – a trend expected to continue for decades to come.[6]

The 2018 Post-Disaster Needs Assessment points to housing as one of the most affected sectors in the wake of climate-related and other natural hazards. Housing is also the most important asset, and often the only significant asset, accrued by the poor. In this context, governments and other institutions such as the World Bank and United Nations are responding with initiatives to build climate resilience and resilient housing. A number of programmes are being implemented in Mozambique, as well as other initiatives in Malawi and Rwanda.

What is resilience and why is it crucial?

Resilient housing is the capacity of human settlements to cope with shocks (environmental, economic and social) and respond to these over time.

Proximity to urban centres and transport hubs increase access to employment opportunities. Job migrants are often too poor to rent or buy in the formal housing market.[7] However about 90 percent of urban expansion in developing countries is near hazard-prone areas.[8] The paradox is that these areas are characterised by sub-standard housing, and as a result the poor are concentrated in high density, low-quality living conditions. The poor often reside in informal or fragile housing, located mainly in peripheral areas, including along riverbanks, on hillsides and slopes prone to landslides, near polluted grounds, on decertified land, in unstable structures vulnerable to earthquakes, and along waterfronts in coastal areas, increasing exposure to climate change.

Furthermore, homes are often built incrementally, with low-quality materials and techniques that are not climate resilient.[9] In a country such as Mozambique where almost half of the population lives in poverty[10], the absence of climate-resilient responses will exacerbate poverty levels. A lack of (financial) resources makes the poor substantially more vulnerable to environmental shocks. Therefore, in developing climate-resilient responses, the capacity of the poor to anticipate and respond, or even have access to adequate and resilient housing, should be considered.  Environmental factors include ensuring houses are not built in flood-prone areas.

The socio-economic implications of climate change have an economic cost, and push poor communities into a vicious cycle of vulnerability and entrenched poverty. Adopting resilient techniques can reduce the associated costs relating to health and loss of productivity, possible displacement and risks such as the use of contaminated water.[11] The cumulative (individual and collective) effects can influence decisions around land management (unregulated urban growth), construction techniques, implementation of water and sanitation programmes, and low investment in education and poverty reduction.[12] In Mozambique, for example, repeated climatic shocks (in the event that global carbon emissions are not constrained) are estimated to contract the economy by up to 13 percent by 2050.[13] This will most likely affect the populations in the Beira corridor.

Targeting resilience building for the poor is therefore an economic, social and environmental imperative.[14]

Affordable solutions for housing resilience

There are several models and initiatives for resilience emerging on the continent. High-level programmes include the World Bank’s Global Program for Resilient Housing. This programme focusses on complementing rebuilding efforts and improving preparedness before disasters. The programme has so far been tested and employed in Latin America and the Caribbean, and Southeast Asian countries such as Colombia, Mexico, Peru, Saint Lucia and Indonesia. The aim is to protect individuals and families and their most important investment, i.e. the housing asset.

The impacts of climate change in Mozambique led to the establishment of the USAID’s and UN-HABITAT’s Coastal City Adaption Project (CCAP) in 2015. The programme supports local governments and communities in the cities of Pemba and Quelimane to develop affordable solutions and techniques for building. Importantly this includes design elements and resilience throughout the construction process (i.e. foundation, walls and roofing) (see Table 1).

Table 1: Key design elements for resilient construction in Mozambique

TECHNIQUE DESCRIPTION
 Low vulnerability site selection

Reduces potential impact of hazards (e.g. avoiding areas with high exposure to flooding and strong winds).

Systems to properly identify risks and allocate plots for construction; improve municipal regulations; and guidance on site selection.
Raised foundation

Elevated platform above the maximum level of flooding.

Built with material that supports weight of the house and withstands storm-force rain; constructed using conventional or mixed materials such as cement bricks, or reinforced concrete beams.
Reinforced wall

With galvanized wire and diagonal poles (at a 20cm separation) and finished with mortar plaster.

Constructed with durable construction material, such as coconut or bamboo wood.
Secure roof with rainwater harvesting capacity

 

Roofing should be symmetrical (square or rectangular) and constructed with an adequate slope to withstand strong winds (not lower than 12.5°).

Materials include purlin, roof batters, rafters and iron rod.

Roofing sheets should be properly nailed into the roof supporting beams and tied with galvanized wire.

Roofing cover sheet must be sufficiently waterproof, constructed with water collection system (gutters and drop tubes) made of suitable PVC and/or aluminium materials, and of a weight that is resistant to winds and can support the rain harvesting system.

Source:  António Casimiro, Brian App and Maria Olanda Bata. “Climate change & resiliencehousing & informalityclimate changeclimate change adaptationMozambiqueurban resilience.” Urbanet, 25 April 2018.  https://www.urbanet.info/climate-resilient-housing-mozambiques-coastal-cities/

Similarly, the World Bank’s Cities and Climate Change Project aims to strengthen municipal capacity for sustainable urban infrastructure and environmental management in Mozambique. The Pilot Programme focusses on the coastal city of Beira, although it is not the only city at risk from climate variability. A core component of this project’s resiliency includes improved management and development of natural drainage systems and longer-term measures of developing green infrastructure.

Although resilient building materials and techniques may turn out to be more costly than traditional methods in the short term (in Mozambique this can be up to 25 percent more), by avoiding the costs of frequent rebuilding and damage to property, savings are expected in the long term.[15]

The Joint 2019 AUHF and IUHF Conference  also shed light on some of the climatic solutions being developed in landlocked countries such as Malawi and Rwanda. In Malawi, Durabric is increasingly being used as a more sustainable alternative to traditional burnt clay bricks (Figure 1). The compressed-earth stabilised block is made using a combination of locally sourced materials – earth, sand, cement and water. It is a more affordable alternative, curbs deforestation and carbon emissions, and builds local capacity.

Figure 1: Soil stabilised brick  

Source: 14Trees. “Accelerating sustainable and affordable construction solutions in Africa.” Presentation at the Joint AUHF IUHF Conference. 4 October 2019. http://www.auhf.co.za/events/http-auhfconference-com/

The PROECCO Programme, which promotes climate responsive building material production in the Great Lakes Region, optimises design and material use. In Rwanda, housing construction involves the use of more modern, high-quality brick (Figure 2).  Import replacement of buildings materials such as cement is core to the Rwandan model and has reduced construction costs by a third, while also boosting local industrial growth. The modular design elements of the construction process increase the potential of the local industry to supply affordable housing for rapidly urbanising cities.[16] The strength of the Rowlock Bond walling system and its para-seismic performance has proved efficient in earthquake-prone countries such as Nepal.

Figure 2: Traditional Brick versus Rowlock Bond Wall

Source: Skat Consulting. Beyond design: A green growth strategy for the mass supply of affordable houses in Africa. Presentation at the Joint AUHF IUHF Conference. 4 October 2018.  http://www.auhf.co.za/events/http-auhfconference-com/

Key lessons

Climate change imposes a huge challenge for Africa’s current and future development. This means the need to integrate resilience into development practice cannot be overlooked. It is particularly important to recognise the unequal burden on the poor and the impact at the household level, which threatens their ability to recover and rebuild. This requires targeted interventions. The challenge lies not only in in constructing new resilient affordable housing, but also retrofitting existing housing structures.

The following key lessons can be drawn from emerging efforts to build resilience, in Mozambique and elsewhere on the continent:

  • Building resilience is complementary with reducing poverty.[17] Disaster risk management and mitigation should therefore be a key component of any poverty reduction efforts.
  • Building resilience into cities and societies requires strategic partnerships between government ministries, municipalities, the private sector, funders and local communities. This should include identifying ways in which to scale-up and adapt programmes such as PROECCO in other regions.
  • Governments can be proactive about building resilience through investing in resilient infrastructure, and by developing land use policies and enforcing building codes for the construction sector.
  • Effective post-cyclone rehabilitation measures should include transitional housing for communities that have been displaced.
  • Given that the majority of low-income households, particularly in Mozambique, self-build their homes, offering technical support on sustainable techniques and practices is crucial for building resilience.
  • Finally, the net benefit of investing in resilience is higher than the immediate cost, and can in turn improve the provision of essential services such as transport networks, water and electricity supply – contributing to more resilient [18]

 

[1] United Nations Economic Commission for Africa (UNECA). “Malawi, Mozambique and Zimbabwe need $4 bn to recover from devastating cyclones.” UNECA, 8 Oct 2019. https://www.uneca.org/stories/malawi-mozambique-and-zimbabwe-need-4-bn-recover-devastating-cyclones.

[2] Global Facility for Disaster Reduction and Recovery (GDFR). GDFR, 2019. “Mozambique country profile.” https://www.gfdrr.org/en/mozambique.

[3]Channing Arndt and Claudia Ringler. “Cyclone Idai shows why long-term disaster resilience is so crucial.” Reliefweb, 5 Apr 2019. https://reliefweb.int/report/mozambique/cyclone-idai-shows-why-long-term-disaster-resilience-so-crucial.

[4] Verisk Maplecroft. “Climate Change Vulnerability Index.” Reliefweb, 14 Nov 2017. https://reliefweb.int/sites/reliefweb.int/files/resources/verisk%20index.pdf

[5]Shreeshan Venkatesh. “Africa: The least responsible, but most vulnerable to climate change.” Down To Earth, 29 May 2019. https://www.downtoearth.org.in/news/climate-change/africa-the-least-responsible-but-most-vulnerable-to-climate-change-60669

[6]Russell Bishop. “Confronting climate change: Africa’s leadership on an increasingly urgent issue.” Brookings Institution, 1 Jan 2017. https://www.brookings.edu/wp-content/uploads/2017/01/global_20170109_foresight_africa_chapter-5.pdf.

[7] Fiona Anciano and Laurence Piper. “How cities can approach redesigning informal settlements after disasters.” The Conversation, 5 May 2019.  https://theconversation.com/how-cities-can-approach-redesigning-informal-settlements-after-disasters-116318.

[8]Sameh Wahba and Mami Mizutori. “It’s time to double down on resilient infrastructure.” The Daily Star, 10 Nov 2019. https://www.thedailystar.net/business/news/its-time-double-down-resilient-infrastructure-1825390.

[9] António Casimiro, Brian App and Maria Olanda Bata. “Climate change and resiliencehousing & informalityclimate changeclimate change adaptationMozambiqueurban resilience.” Urbanet, 25 April 2018. https://www.urbanet.info/climate-resilient-housing-mozambiques-coastal-cities/

[10] World Bank. “Mozambique economic update: Less poverty, but more inequality.” 14 November 2019. https://www.worldbank.org/en/country/mozambique/publication/mozambique-economic-update-less-poverty-but-more-inequality

[11] Casimiro, App and Beta. “Climate change and resilience.”

[12] Herlander Mata-Lima, Alvino-Borba Andreilcy, Adilson Pinheiro, Abel Mata-Lima and Jose Antonio Almeida. “Impacts of natural disasters on environmental and socio-economic systems: What makes the difference?” September 2013. http://www.scielo.br/pdf/asoc/v16n3/en_v16n3a04.pdf

[13] Arndt and Ringler. “Cyclone Idai.”

[14] Mata-Lima, Andreilcy, Pinheiro, Mata-Lima, A and Almeida. “Impacts of natural disasters.”

[15] Casimiro, App and Beta. “Climate change and resilience.”

[16] Skat Consulting. “Modern brick construction systems: A catalogue of affordable solutions made in Rwanda.” July 2017. http://madeingreatlakes.com/wp-content/uploads/2017/07/CAT-MODERN-BRICK-SOLUTIONS-Draft-Third-Edition-Beta-Version2.pdf

[17] Stephane Hallegatte, Adrien Vogt-Schilb, Mook Bangalore and Julie Rozenberg. “Unbreakable: Building the resilience of the poor in the face of natural disasters.” World Bank Group, 2017. https://openknowledge.worldbank.org/bitstream/handle/10986/25335/211003ovEN.pdf

[18] Stephane Hallegatte. “Resilience for the most vulnerable: Managing disasters to better protect the world’s poorest.” World Bank Blogs, 19 July 2017. https://blogs.worldbank.org/voices/resilience-most-vulnerable-managing-disasters-better-protect-worlds-poorest

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