Group C - Collaborative Climate Adaption Project
| Area | Coastal | |
| Country | Thailand | |
| Topic | Mangrove Restoration in Coastal Thailand | |
| Author(s) | Christopher Boone, Helena Van Boxelaere | |
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Rationale: Reasons for Mangrove Reforestation in Coastal South East Asia
The world is full of myriad ecosystems, each with different variables of location, biodiversity, climate patterns, nutrient systems, geography, etc. And as the study of the effects of Climate Change continues to expand and deepen, we begin to learn that there is no single, conveniently scalable solution to this issue. In actuality, almost every effected ecosystem is going to require a specific case study to map out the sources of its strain, and to diagnose a site specific solution. This is at the heart of the riddle of Climate Change; it is the diversity of effects on global ecosystems that makes gives this issue its complexity.
The case for studying coastal cities in Southeast Asia has a lot to do with what Climate Change scientists have already learned through their study. The phenomenon of increases in global atmospheric temperatures has a great number of effects around the world, but possibly one of the more immediately dire is the noted decrease in glacial ice due to melting. Scientists have noted an accelerating rate of polar ice cap recession, and while there were some projections made in years past, continued examination has led researches to question if polar ice melting is not actually occurring even faster than originally thought. The connection between melting polar ice and Climate Change in tropical Asia is the rise of global sea levels; all that melting ice is raising the global water level, and this poses to have massive effects on coastal cites around the world. [1]
Recently, guest speaker Asan Suwanarit from Thammasat University in Thailand gave a presentation about the devastating potential effects of storm surges and consequent flooding in the specific case of Bangkok, an example of a major coastal city in S.E. Asia. His report provided an eye-opening perspective on the extent of damage that the effects of Climate Change can have on this set of human settlements, ranging from financial losses and the costs of redevelopment, damage to city infrastructure and the related public health risks, loss of home and the creation of a refugee group, etc. Essentially, he demonstrated that coastal cities stand to receive a lion's share of damage due to the effects of Climate Change.
Further research into the case of storm damage and flooding in coastal Asian cities has shown that another piece of the puzzle may be the existence of a plant species called Mangrove. [2] It turns out that naturally, this twisted, stunted tree species normally provides a great many services to coastal ecosystems, by providing a nursery for young aquatic species, by sinking a great deal of atmospheric Carbon through its growth, and by its function as a coastal buffer against storm surges. [3] Mangroves naturally grow in thick belts along tropical Asian coastlines; they thrive in shallow saline water environments, and historically provided a kind of shield along most Asian coasts. However, human activity such as aquaculture, shrimp farming and the development of coastal cities has led to the destruction of many Mangrove populations, and this is certainly linked to the devastation of storm water surges, flooding, and the phenomenon of rising ocean water levels.
Fortunately, attention to the possible solution of Mangrove reforestation has led to a number of ongoing projects of this type in India, Indonesia, and Thailand, among other places. This has created a good amount of publicity and has led to several thorough reports detailing the effectiveness of these projects. One such document, produced by Oxfam, can be read here. [4] It shows that Mangrove remediation serves as a realistic tool in combating the effects of Climate Change in this region.
The combination of good documentation of the effectiveness of mangrove reforestation in S.E. Asia, as well as the specific vulnerability of coastal Asian cities due to rising ocean levels, led to the decision to focus on this region as a case study.
Authors' perspectives
My professional perspective for the case study of mangrove remediation in coastal S.E.Asia is largely as an academic researcher, but also as a first hand witness. Having spent several months in travel and on-site research in the region, I have a great deal of interest and empathy for the plight of this region, due to its specific vulnerability to disastrous Climate Change effects. I saw a great amount of foreign investment into the commercial realm of the area, much of which was concentrated along coastlines for the obvious tourism market, and as a result there should be a synonymous investment into infrastructure and defense. Mangrove reforestation is one such example that is simultaneously low-cost, natural and local. Also, in attendance of the COP 15, I heard representatives from several Asian nations site the threat of rising ocean levels as grounds for special attention to be given to their nations, as this phenomenon is going to make a strong effect, and soon. While we should certainly try to take simultaneous action all over the world, if there is a finite amount of funds or support from international protection organisations then perhaps the case could be made to priorities based on time and urgency.
Landscape and/or urban context
The landscape and urban context of coastal Thailand varies depending on region, but there has historically always been a strong affinity in the Thai culture for coastal residence. And while rising oceanic levels and subsequent intensifying storm surges can have potentially devastating impact to human life and built structure, it depends on the site impacted. It is a phenomenon of human empathy and emotion that we view natural destruction as negative or unnatural when it impacts the human species, but not the natural wild. Yes, there is also the fact that storms may be intensifying largely due to human-created factors (CO2 leading to rising global temperatures leading to rising sea levels), but in on a larger context of time, bad storms occur naturally. An uninhabited coastline in Asia will receive a flood or killer wave and process it naturally, indeed, it may be a necessary part of that region's ecological cycle,its biogeography. An analogy would be uncontrolled brush or forest fires in the American Midwest, where some pine species actually rely upon sudden fires for their natural queues for reproduction; human intervention to control these "unwanted" fires may be negatively affecting the propagation of these pine species. That is why the redevelopment of the natural mangrove forests is a desirable solution; these forests were here before humanity removed them in commercial expansion. The mangroves grew in these sites naturally, they are a part of the very ecosystem that simultaneously exists and regulates itself, storms and all. Biomimicry is a solid foundation for interpreting adaptive landscape architecture solutions to Climate Change.
With human expansion, land use patterns have grown up around coastal areas for a great many reasons, and usually the most insightful manner of examining this question is through an old journalism mantra: Follow the Money. Coastal cities benefit financially through easy access to trade, to coastal rich fisheries, through nutrient rich coastal agricultural lands, and most recently through touristic attraction. These factors will always lead to concentrations of built human structure and infrastructure along coastal lines. As these cities (and the citizens that populate them) realize their profitability, they will trend towards growth. In other words, the trend is towards increasing built up areas, decreasing green/blue areas. Take into consideration that many people with little or no money for self-preservation, insurance or sound housing will also seek work in these coastal cities, and you can then understand why coastal storm surges have such devastating potential. Makeshift houses made of plywood or bamboo may not tolerate a rushing wall of water.
Historically, we can look at the Sumatra-Andaman Earthquake and subsequent Tsunami of 2004 as a case study. This unprecedented shock and flood resulted in damage on a scale never before seen in that area in recorded history. While there was a great deal of money and resources invested in that region, not enough of it was in the sector of natural defense or catastrophe prevention, which is what we now look to correct. Countries like the Netherlands may have resources, politics and foresight enough to build defensive dikes, but in the case of developing Thailand, we must look for more realistic adaptation strategies. Que, Mangroves.
Cultural/social/political context
The kingdom of Thailand is located in the heart of Southeast Asia, neighbouring the countries of Myanmar, Laos, Cambodia and Malaysia. Thailand has a population of 65 million people. Striking is that the majority of the population is living in rural agricultural areas and not in the major cities like the country’s capital Bangkok. Thailand stretches from the mountains and forests up north to the tropical islands and peninsula in the south, with large important rice field plains in the centre. Thailand is the world’s largest exporter of rice and therefore the agricultural business is of great importance for the country’s economy. Apart from agriculture and rice cultivation, tourism and fishing are also very important economic drivers; both abound on Thailand’s 3,200 kilometres of coastline. Significantly, Thailand and especially Bangkok is an important political and social centre, for the greater Mekong region and as a global city.
Local Climate
Thailand’s climate is tropical and humid during most of the year and for the majority of the country. In general, two or three seasons can be distinguished, depending on the region. In the north of the country, the climate from March to May is hot and rather dry. The period from June to September is very rainy, because of the southwest monsoon domination, with plenty of sunshine. October to February is rather cool and dry. In the southern region, two seasons can be distinguished: dry or wet. The southwest monsoon brings rain an heavy storms from April to October (on the west coast) or from September to December (on the east coast). Each year, the country gets up to 2,400 millimetres of rain, often causing major flooding in the north, north eastern and central regions.
Analysis of vulnerability
Thailand is the world’s largest exporter of rice and thus rice cultivation is a very important economic activity. Next to agriculture, trade and tourism are the major sectors of Thailand’s economy. However, all three of these pillars are threatened by climate change. Consequences of climate change such as increasing surface temperatures, floods, droughts, severe storms and sea level rise threaten the annual rice crops, as well as the submergence of Bangkok within a reasonable time. A few centimetres of sea level rise are enough for flooding the capital and for damaging the important coastal tourism. Figure 1 shows the vulnerability to climate change within the country and espcially the west of the country and the coastal area (including Bangkok) are at high risk. Thailand’s economy will be serious under threat due to climate change. According to IPCC-projections, the combined GDP of Thailand, Indonesia, the Philippines and Vietnam may shrink by 6,7% by 2100 because of climate change-related risks.(D’Agostino et al, 2012) However, apart from economical damage, Thailand’s inhabitants, local communities and the precious ecology will inevitable be affected as well.
Related to climate change, flooding is the major threat for the extensive coastal areas of Thailand. Thailand has a delicate coastal zone of over 3,200 kilometres. Uncontrollable natural disasters such as the 2004 tsunami already showed the extreme vulnerability of Southeast Asian’s coast regions. Because of poor environmental management, the disaster’s effects were aggravated and the consequences were huge. For example, in absence of natural protective barriers like mangrove forests or coral reefs, the giant killer wave carried its energy all the way to the shore, devastating a huge area. In other places, where the barriers were present, the wave’s energy was diminished and the causing far less damage. Coastal erosion, mangrove loss and coral reef destruction due to human activities keep magnifying the vulnerability of those coastal regions. And in the future, additional threats due to anthropogenic climate change, will threat this region even more, further increasing its vulnerability.
D’Agostino, A., Meenawat, H., Rawlani, A., Sovacool, B.K., 2012. Improving climate change adaptation in least developed Asia. Environmental Science & Policy 21, 112-125.
Jin-Eong, O. (1995). The ecology of mangrove conservation & management. Hydrobiologia. 295, 343-351.
Climate Change Adaption and Mitigation by Restoring Mangrove Forests
Mangroves are evergreen forests that are physiologically adapted to some extent of salt (sea) water submersion. Survival in brackish water is made possible by several smart adaptations, including a complex root system that partly protrude above the water, supplying the plant with oxygen and allowing a firm position. This way, mangrove trees are able to withstand a stormy water, in addition holding the earth and sediments beneath as well. Mangrove forests are outstanding ecosystems, characterized by high levels of biological production and an enormous diversity in species and habitats. They are to be found in the intertidal zones between sea and land in brackish water areas of tropical and subtropical regions. All along the tropical and subtropical coasts of most continents we can find mangroves, hosting a multitude of life forms between their dense root system. Mangrove forests are important for a multitude of reasons.(Figure 2) They house an enormous variety of species and habitats, witnessing the evolution of adaptation to wet and salty environments. Mangroves retain nutrients and organic matter cycling, immobilize pollutants and have an important share in mitigation of greenhouse gas. Especially in storage of carbon they are very important, having a carbon sequestration potential greater than many tropical forest. In addition, they support 80% of the global fish catch and provide seeds for aquaculture. For locals, mangrove forests are an important resource as well, providing construction timber, firewood, food, hunting grounds, fisheries, manure, medicines, etc. Traditionally, local communities have been sustained by mangroves for centuries, thanks to a balanced and sustainable use of the forest. Apart from a rich biodiversity and being an important resource, another major advantage of mangrove forests is their coastal protective features. The complex root systems prevent erosion by retaining and fixing sediments and they withstand stormy water of floods/ tsunamis and heavy weather conditions by decreasing wave energy. Mangrove forests among the coast constitute a broad protective belt and wide buffer between sea and land. Therefore, they play a role in protection against extreme weather events and coastal erosion.
At present, we know our climate is changing. The average global temperature is increasing, making sea levels rise and therefore, more storms and cyclones are expected, putting coastal areas under much more pressure and increasingly, it appears that measures need to be taken. In relation to adaptation to climate change, mangrove forest can play an important role. As an alternative for expensive and monofunctional constructions such as storm surge barriers, flood defence systems or super dikes, natural solutions are gaining wider focus, as does mangrove forest restoration. However, the past decades, mangrove forests were used far beyond sustainable levels causing the loss of enormous areas of forest over time. Among many coasts, mangroves deprived and disappeared due to several reasons. (Figure 3) A major threat to mangroves is the population pressure. All over Asia, little areas of mangroves are left where populations near the coast are high. Second, the conversion of mangrove forest to aquaculture ponds (E.g. prawn ponds ) has caused major losses, as did the mangrove wood-chips industry. Mangrove forests have been cleared of timber for the production of wood-chips. These practices (often done by foreign operators) are only focussed on quick harvesting and do not take into account the environment or the local communities. Another major threat is the reclamation of land for a variety of purposes such as industrial development or housing and port construction. However, many other reasons cause the loss of precious mangrove forest area. That way, valuable resources and habitats vanish and adjacent lowlands and deltas become much more vulnerable for high floods and storms.
In the past, the role of mangrove forest for coastal defence and for saving lives has been remarkable. In 2004, at some places mangroves absorbed the strength of the tsunami waves and protected the shorelines of southeast India. Five years for this, a cyclone in India killed almost 10,000 people and destroyed livestock and property. Previously, mangrove forest in the area got damaged or simply disappeared. However, if the forests had been intact, it is sait that more than 90% of the human deaths would have been avoided.
(to be continued...)
Bats, de N. (2011). Untangling the Roots. (Thesis disseratation) Wageningen University.
Fiselier, J.L. (1988) Living off the tides. Environmental database on wetland interventions.
Jin-Eong, O. (1995). The ecology of mangrove conservation & management. Hydrobiologia, 295, 343-351.
Kathiresan, K. & Sandilyan, S. (2012) Mangrove conservation: a global perspective. Biodiversity Conservation, 21, 3523-3542.
Your scenario
Scenario Case Study Focus: Krabi beach, Phangnga Bay in southern Thailand, year 2060
In the past fifty-five years both disaster prediction technology has improved vastly, but also we have seen extensive growth and maturation in the mangrove bio-remediation project along the coastline. Because of the presence of the popular tourism business in Krabi beach, there was strong initial resistance to reducing the ocean view along the resort and hotel-dense stretches of white sand beaches. However, by creating a targeted media campaign including witness reports and video/photographs from the catastrophic tsunami of 2005, enough support was rallied to move along with the extensive offshore mangrove nursery.
In an attempt to minimize the effect of the project on Krabi's chief industry of tourism, attention was paid to some of the more powerful mangrove remediation projects, such as those along southeastern coasts of India. There, offshore mangroves form a buffer thirty kilometers thick, which creates a highly effective barrier against potentially damaging storm water surges, in addition to the great role it plays in fostering local biodiversity, filtering and purifying water, and as an effective carbon sink to combat atmospheric CO2 concentrations that can lead to climate change.
Special measures were taken off the case study area of Krabi to implement thick mangrove barriers, as the effectiveness of this tactic was found to be increased incrementally by planning and growing a wider swath of forest. An important study conducted by the SOFIA group in the barrier mangrove forests in southern Florida, USA provides the hard figures pertaining to wave velocity, attenuation of force, and the comparative advantage of forest breadth. That information, developed in collaboration with the United States Geographic Survey, is delivered in a concise paragraph available, here: [15].
Essentially, that study found that while the sudden impact of storm waves or surges with the outermost edge of mangrove forest would create a spike in wave amplitude, (which would mean greater damage to any structures existing on the outside of the barrier), the force of the surge as it passes through the midst of the mangroves would be reduced greatly, (at approximately 40-50 cm/km) and more so with a wider section of forest. In accordance with these facts, the Krabi Beach Mangrove Shield project was originally planned to grow to sufficient width to provide strong protection to the human population and built structure there.
Over the past fifty five years, we are happy to report that the mangroves have grown to reach critical width and density, and now protect Krabi.
What can be generalized from this case study?
There are several theoretical insights that can be generalized from this case study. First and most importantly, the fact stands that mangrove forests grow naturally in the majority of the tropical world. This means that the case study at Krabi, Thailand could be theoretically scaled and modeled to any other threatened coastline in the central latitudes. Other insights stem from the secondary characteristics of mangrove forests: because of their capacity to sequester Carbon from the atmosphere through photosynthesis, and to bind and hold that Carbon in place while simultaneously creating wildlife habitat, it follows that mangrove reforestation should be conducted on a wide scale to combat climate change.
Research could be conducted in close cultivation with mangrove varietals, in order to determine which, if any, species provide a reasonable advantage in the bioshield strategy over others. Also within this research could be to target specific planting patterns to further break up storm surges. Depending on the frequency and predictability of the presence of waves, perhaps mangroves could be utilized to channel water flow for commercial or industrial purposes. For example, brackish water estuaries are often used for commercial fish farming; mangroves can provide both protection from extreme influx of water, as well as controlled, directional channeling. Research should be conducted to combine these two ideas; there could be a collaborative advantage to fisheries design and maintenance through utilization of mangrove forests.
Mangroves are one of a relatively small set of trees that thrive in the presence of high salt concentration; perhaps a biochemical research project could yield some insight to natural desalinization techniques. Many of these same tropical areas that support mangrove forests so well are also in need of clean water solutions.
Working on the case study of mangroves in tropical coastal storm defense has been an enlightening exercise in landscape architecture, biomimicry, climate change, and international disaster relief. I've come to the conclusion that by addressing climate change and environmental remediation issues in conjunction with landscape architecture and design, dynamic solutions can be discovered that can solve a host of problems, while also satisfying the initial set of design specifics. It is encouraging to feel that such a symbiosis can exist, even more so to see that this is, in fact, the standard case in most healthy ecosystems.
Presentation Slides
Image Gallery
Coastal geography at Ton Sai beach at low tide,rural southern Thailand adjacent to the case study area of Krabi
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References
Sterrett, Charlotte. (2011, Nov. 16) Review of Climate Change Adaptation Practices in South Asia. Oxfam Research Reports.
Stecker, Tiffany. (2012, July 31) Restoring Mangroves May Prove Cheap Way to Cool Climate. Climatewire. Scientific American. Internet article. Retrieved Dec. 2012. http://www.scientificamerican.com/article.cfm?id=restoring-mangroves-may-prove-cheap-way-to-cool-climate
Sea Level Rise, National Geographic. Internet article. Retrieved Dec. 2012. http://ocean.nationalgeographic.com/ocean/critical-issues-sea-level-rise/
Declining Mangroves Shield Against Global Warming. Phys.org. Internet article. AFP (2011) Retrieved Dec. 2012 http://phys.org/news/2011-04-declining-mangroves-shield-global.html
Erftemeijer, P.L.A., Bualuang, A. Participation of Local Communities in Mangrove Forest Rehabilitation in Pattani Bay, Thailand: Learning From Successes and Failures. Retrieved Dec. 2012. http://www.globalrestorationnetwork.org/uploads/files/CaseStudyAttachments/54_pattani-bay.pdf
Selvam, V.; Ravishankar, T., Karunagaran, V.M.; Ramasubramanian, R.; Eganathan, P.; Parida, A.K. Toolkit for establishing Coastal Bioshield. Retrieved Jan. 2013. M.S. Swaminathan Research Foundation. http://www.mssrf.org/csr/csr-pub/17-Toolkit%20for%20establishing%20coastal%20biosheid.pdf
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