Bamboo for Disaster Risk Reduction & Resilience
Main Contributor: Apsana Kafle
Other Contributors: Sarah Stuttaford, Sara Hamann, Arthur Lindhjem
Bamboo for Disaster Risk Reduction and Resilience
Disaster is a sudden, natural, or human-induced calamitous event which drastically disrupts the functioning of a community and the society as a whole. This has direct human, material, economic and environmental losses that exceed the community’s or society’s ability to cope using their common resources (IFRC, 2020). Some of the most common disasters occurring globally are floods, storms, earthquakes, landslides, droughts, wildfires, volcanic activity, etc. Disasters have a fairly significant global impact on the economy, ecology, and society as a whole. The ability of any system to bounce back from the disaster and rebound forward is known as resilience. The 21st century is seeing a heightened intensity and frequency of these disasters as they become more unpredictable and deadly.
Bamboo is a fast-growing perennial, that has wide use ranging from basic subsistence purposes to commercial construction and ecosystem restoration. Out of the various functions derived from bamboo, disaster risk reduction and resilience can be the most important. Today, disasters have cost more lives not only during their occurrence but also due to lack of preparation. There are two ways through which bamboo can be a possible solution for disaster resilience and reduction. Firstly, it can help to minimize the frequency of disasters, reduce the potential impacts from them, and most importantly help, to restore ecosystems and the economy after disasters.
Bamboo for Disaster Risk Reduction
Bamboo has been used to combat wind and erosion for decades. Bamboo has a vast network of roots and rhizome which strongly helps to bind the soil, thereby resisting erosion induced by natural sources such as wind and water.
Bamboo can be used as an important bioengineering structure as well. Planting bamboo along the river corridors and bunds helps to protect the river from being breached and prevent rapid runoff. It is often planted in erosion-prone areas along with erosion control structures, e.g., embankments and check dams. Being a pioneer species of plant succession, it can easily be grown on degraded land. When proper techniques are considered while harvesting bamboo it does not impact the topsoil like other trees thus reducing the probability for erosion and displacement of soil.
Bamboo is evergreen in nature which grows in all seasons. As a result, it covers the surface of the ground and increases the infiltration capacity of the soil. This not only helps with surface erosion but also maintains the water table below the surface. Bamboo can also help to decrease the evaporation of water from ponds and help further water conservation. Bamboo leaves can be used as an important source of organic manure which can be a great alternative to industrial fertilizers which have a direct role in land productivity and conservation.
Some of the exemplary species of bamboo which play a good role in providing coverage to the earth against soil erosion and sunburn are Sasa bamboo (Sasa palmata) in China (INBAR, 2000), Moso bamboo (Phyllostachys edulis) on the abandoned landslide sloppy areas of Nepal (DFRS, 2018), Giant bamboo (Dendrocalamus Asper) on the flood-prone corridor of Timor Leste (DARDC, 2018). In all of these cases, planting bamboo has not only protected against disasters but has also contributed to upscale the livelihood of the associated communities.
Some of the post-disaster consequences include the transformation of land structure, succession, disruption in the natural cycles, mass movement of people. These events have severe implications, especially on natural resources as displaced people put on extreme pressure on natural resources. Previous studies in Rwanda had shown the severe degradation of the natural resources by people for rebuilding their livelihood. An estimate (UNHCR/CARE/ERM) of the fuelwood needs by the displaced people in the area demanded the resource at an average of 2.6/person/day. This was when 524,000 refugees were interpolated among the community, and a daily supply of some 1,603m3 of fuelwood was needed – approximately 585,095m3 per year.
Bamboo for resilience
One way to acquire resilience is through rebuilding structures that are not only strong, durable, and affordable but even prevent further occurrences of future disasters. Bamboo can be used as an important construction material as it can provide long-lasting building materials that can be easily harvested within 3 to 5 years when managed and treated properly. Worldwide bamboo is widely distributed among 1662 species and 121 genera and is available anywhere from the tropics to the mild temperate zones. It is accessible and versatile, growing along the hillsides, walkways, river corridors, etc.
Bamboo exhibits properties such as hardened culm, high growth rate, and versatility which makes them equivalent and most often superior to wood structures. Unlike the construction industries like steel and cement, bamboo is the best alternative material as it has a high CO2 sequestration capability which plays an important role in any future climate-induced disasters. Besides, the tensile strength of bamboo is 28,000 pounds per square inch which is much higher than steel (23,000 pounds per square inch). This means that during high-stress events, like hurricanes or an earthquake bamboo, can provide higher strength than steel (INBAR, 2000). Bamboo also has greater stiffness (mass per volume) which has a higher practical experience and importance. For instance, if a bamboo house has suffered from a heavy earthquake, only partial elements in the bamboo might show damage to the house being still habitable and standing. They are light in weight and thus able to withstand more loads. Besides bamboo also has properties like greater bending strength which makes bamboo houses and infrastructures disaster resilient. The bamboo rooftop also consumes less energy than conventional building materials which helps in regulating the temperature and reduce indoor energy consumption.
Lastly, in the midst of uncertainties and the proliferation of disasters, bamboo-based solutions are sustainable, reliable, and practicable. The multi-disciplinary function of bamboo prevents the occurrence of disasters, reduces the intensity of their impact, and most importantly helps to recover and rebuild the losses from disaster in a more sustainable way.
Additional Resources on this topic
Bamboo and rammed-earth therapy center in Bangladesh wins 2020 Obel Award
How does it relate?
The winner of the Obel Award, German architect Anna Heringer, uses her mud and bamboo design to illustrate sustainable values and respect for the culture and land use. And also how to build a modern building with simple and local resources, an important lesson that can be useful in the wake of natural disasters.
Contributor: Sara Hamann
Read the article here
Stories that change the paradigm: bamboo structures for sustainable and resilient communities
How does it relate?
Whether it be reducing flood risk or combatting the unsustainable practices of urbanization, bamboo is a versatile solution for the low-income communities of the Asia Pacific.
Contributor: Sarah Stuttaford
Read the article here