Journal of Forest and Environmental Science

Institute of Forest Science, kangwon National University (강원대학교 산림과학연구소)
권호 표지
DOI QR코드

DOI QR Code

Wind Speed Reduction Efficiency of Potenga-Muhuri Irrigation Project Coastal Belt in Chittagong, Bangladesh

  • Kader, Mohammad Abdul (WinMiaki Ltd.) ;
  • Hossain, Mohammed Kamal (Institute of Forestry and Environmental Sciences, University of Chittagong) ;
  • Kabir, Md. Humayain (Institute of Forestry and Environmental Sciences, University of Chittagong)
  • Received : 2018.05.01
  • Accepted : 2019.04.21
  • Published : 2019.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

Coastal plantation is one of the key natural defence against the tidal surge induced tropical cyclones. In Bangladesh, a total of 81 km long coastal belt was established from Potenga to Muhuri in Chittagong. This study explores the wind protection efficiency of the coastal plantations at 28 observation points along the 81 km long Potenga-Muhuri irrigation project of Chittagong coastal belt. We found that wind protection efficiency was lowest (1.40% and 7.00%) at $1^{st}$ observation point of outside the embankment (OE) and inside of the embankment (IE) than Sea Shore (SS), respectively. On the other hand, the highest (82.89% and 95.72%) wind protection efficiency was observed at $22^{th}$ observation for Outside of the Embankment (OE) and Inside of the Embankment (IE) than Sea Shore (SS), respectively. This study also highlighted on species specific wind protection efficiency. The result revealed that 6-year old Casuarina, 6-year old mixed plantation and 10-year old Sonneretia apetala with the width of 20.12 m, 30.48 m, and 15.24 m can reduce wind speed up to 30 H, 30 H and 25 H at windward side, respectively. Analysis also showed that percentage of wind reduction was significantly higher at plantation coast than barren, and ship breaking yard coast. The findings of this study have great potentiality to contribute substantially to take more coastal embankment afforestation programs by the Government of Bangladesh and to choose the more wind resistant plant species throughout the coastal areas of the country.

Keywords

Introduction

Bangladeshis one of the worst victims of devastating tropical cyclones (Government of Bangladesh 2008). The funnel-shaped northern portion of the Bay of Bengal causes tidal bores when cyclones make landfall, and thousands of people living in the coastal areas have been affected. Some of the most devastating natural disasters in history with high casualties were tropical cyclones that hit the region now forming Bangladesh (Government of Bangladesh 2008). Of the 508 cyclones that have originated in the Bay of Bengal in the last 100 years, 17 percent have hit Bangladesh amounting to a severe cyclone almost once every three years. The tropical cyclones and associated storm surges have great impact on the life, property and economy of coastal Bangladesh and particularly on the crop, and fisheries sector and thus on the livelihood of the coastal inhabitants. The tropical cyclones of 1970, 1991 and 2007 estimated to have killed approximately 500,000, 140,000 and 3,363 people, respectively (Ministry of Environment Forests 2009). Under climate change induced cyclone and storm surges, with increasing frequency and intensity, this effect will be enormous in future (Quadir and Iqbal 2008).

The coastal areas of Bangladesh have a high cyclone frequency. For the protection measures, the Forest Department of Bangladesh initiated a mangrove afforestation program in 1965-1966 (Senger and Siddiqi 1993). Coastal afforestation has proved as an effective measure in some parts of the coastal belt of Bangladesh during the 1991 cyclone (Ahmed 1999). Not only in Bangladesh, forests provided natural defense against the disaster by acting as natural levees in Japan. In Iwate and Fukushima prefectures, there were about 10 cases in which forests prevented cars and ships that had been swept up by tsunami from being carried into residential areas. In contrast, areas near port facilities and other places without protection from forests suffered much greater damage (Das and Crépin 2013). Many researchers agreed that coastal forests reduced wind speed and play a significant role in reducing damage from oceanic disasters in coastal areas (Zhu et al. 2000; Takle et al. 2006; Santiago et al. 2007; de Zoysa 2008). Zhu et al. (2000) indicated that the relative wind speed within the forest belt is influenced by the distance from the edge of the forest belt, and the wind direction and topography.

Mangrove trees serve as a wind-break (Christensen 1983). Wind reduction was greatest at 2H and decreased with height and distance from the shelterbelt. Considering the importance of wind speed reduction, coastal afforestation along the coast and offshore island with mangrove species was initiated by Bangladesh Forest Department under a scheme named “Coastal Afforestation Scheme” to protect coastal life and properties from tidal surges and cyclonic storms since 1966 (Chowdhury 1982). Besides, supply of industrial raw materials and fuel wood production, conservation of coastal ecosystem and the environment, protection of wildlife and aquatic resources, protection of agricultural land against salinity intrusion, ecotourism, poverty reduction, and enhancing land accretion were added to the objectives of coastal plantation programs. Currently, the coastal plantation unit of Bangladesh Forest Department is divided into four Coastal Afforestation Divisions named Chittagong, Noakhali, Barishal, and Patuakhali and further subdivided into 28 Forest Ranges, and 198 Forest Beats (Drigo et al. 1987; Government of Bangladesh 2008). An area of 170,000 hectares newly accreted char lands has planted till 2010, although some plantation areas were failed (Aziz 2010). To build a green belt along the coastline, the Bangladesh Forest Department (BFD) has implemented the ‘Coastal Green Belt Project’ from 1995 to 2002 and planted another 635 hectares on foreshore islands with people’s participation. The BFD has implemented the ‘Costal Char Land Afforestation Project’ (2005-2006 to 2009-2010) at a cost of BDT 180 million for raising 11,150 hectares mangrove plantations with Keora (Sonneratia apetala) and Baen (Avicennia officianlis, Avicennia alba, Avicennia marina). Besides, BFD launched community participatory rehabilitation of old plantations with non- mangrove species on 2,500 hectares (Islam 2007). As a result, the coastal plantations have been providing enormous benefits to the coastal people through supplying a source of fuelwood, timber, increasing fish population, and land stabilization. Evidences show that such plantations significantly reduce the damages of cyclone and tidal surges in the Southern Bangladesh, e.g. SIDR, AILA etc. However, in Bangladesh, till to date there is no study to examine the efficiency of coastal afforestation in reducing the wind speed to protect the coastal life and resources from tidal surge induced tropical cyclones. Therefore, this study was aimed at to examine wind protection efficiency of existing coastal forest belt selecting an open long exposed coast of Chittagong starting from Potenga to Muhuri Irigation Project. This study can be a basis of future research on cyclone protection efficiency by coastal belt to protect nearby coastal community. Besides, the findings can help a coastal manager to design effective coastal forest belt with optimum height, density, width and species composition to reduce the cyclone intensity which ultimately save human life and livelihood option.

Materials and Methods

Reconnaissance survey and secondary data collection

A reconnaissance survey was conducted in barren coast, moderately dense plantation coast, dense plantation coast, ship breaking yard along the embankment from PottengaMuhuri Project. This survey was executed in September 2011. The main purpose was to select the sampling design for data collection. During this visit, the tree species specific influence on wind speed reduction was also measured.

Wind speed measurement

Wind speed was measured by Digital Anemometer in three different locations, i.e. Seashore (SS), outside the embankment (OE) and inside the embankment (IE) with three replications in each measurement location (Fig. 1). Replications were taken every 5-minute interval. Outside Embankment and Inside Embankment measurements were executed after 15 minutes and 30 minutes, respectively, from the Seashore wind speed measurement through Anemometer. The sampling locations were selected randomly in every 3 km interval using GPS tracker following the guidelines from the relevant studies (Wang and Takle 1996; Brandle et al. 2000; Zhu et al. 2003). All the primary data of wind speed measurement was collected during May-June, 2012. Besides, six small patches of plantation (three Casuarina plantation, and another three mixed plantation) were chosen purposively. Of which first two were in Bashbaria Forest Beat and rest one was in Boagachattar Forest Beat, Chittagong. In both plantations, tree spacing was 2 m×2 m, but in mixed plantation there was some natural regeneration of tress such as Erythrina pp. (Mander), Pongamia pinnata (Kerong) and Terminaliaca tappa (Kat Badam). The average height of plantations was measured by Spigel Relascope and the width of trees in plantations was measured by measuring tape. Wind speed was measured by Vane Anemometer at 2.13 m above ground with 3 replications of each wind ward and lee ward side of the plantations.

SRGHBV_2019_v35n2_78_f0001.png 이미지

Fig. 1. Geo-location of wind speed measurement points in the Pottenga-Muhuri Irrigation Project of Chittagong Coast in Bangladesh (s, sea shore; m, outside the embankment; i, inside the embankment).

Among the 28 sampling locations, 12 from the barren coast, 12 from the plantation coast and 04 from the shipyard area were taken into consideration for wind speed reduction efficiency analysis. However, four sampling points in the shipyard area was affected severely in Chittagong-Dhaka highway. Although the barren and plantation coast sampling locations were not continuous, for better analysis we assumed the collected data as continuous for comparative assessment. Data have been analyzed in percentage reduction transforming field replications, which then represented by table, bar diagram, graph and pie chart. SPSS (Statistical Package for Social Science), Microsoft Office Excel software were used for necessary statistical analysis.

Results

Wind speed

One of the main functions of coastal forest shelterbelts is to reduce the wind speed. The efficiency of wind speed reduction by a forest shelterbelt is determined both by its external structure, such as width (W), length and shape (Wang and Takle 1996; Wang and Takle 1997; Vigiak et al. 2003; Lee et al. 2010) and also by its internal structure, such as total area density (Torita and Satou 2007), the vegetative surface area (Zhou et al. 2005), and the amount and distribution of solid and open portions, i.e., porosity (Santiago et al. 2007). Therefore, it is important to understand how each structural feature affects the wind speed reduction efficiency of a shelterbelt.

This study found that average maximum wind was highest (22.86 km/hr) at SS, and lowest (7.4 km/hr) was at Sitakunda station during the study period. In day-wise average basis, maximum average wind speed was (19.89 km/hr) on May-04 whereas minimum was (7.40 km/hr) during June-08 (Table 1). On the other hand, in case of Sea shore, maximum average wind speed (28.79 km/hr) was on June-11, while minimum (16.37 km/hr) was on June-06 (Table 1).

 Table 1. Maximum wind speed (km/hr) in Potenga-Muhuri irrigation project coastal belt of Chittaong coast in Bangladesh

SRGHBV_2019_v35n2_78_t0001.png 이미지

Sep of 2011 and May and June of 2012.

SS, sea shore; A, Casuarina and mixed plantation site (Bashbaria); B, Sonneretia apetala site (Bogachattar).

Source: station’s data collected from the Bangladesh Meteorological Department, 2012.

Orientation of wind with belt

During the study period (May-June, 2012), average value showed that difference of angle of orientation was similar approximately similar at Potenga, Ambagan, Sitakunda and Maijdee stations which was 18.81o , 18.94o , 15.44o and, 16.38o , respectively. In day-wise orientation, there was variation from 13o to 21.75o (Table 2).

 Table 2. Orientation of wind in Potenga-Muhuri irrigation project coastal belt in Chittagong during the study period (May-June, 2012)

SRGHBV_2019_v35n2_78_t0002.png 이미지

Sep of 2011 and May and June of 2012.

SS, sea shore; A, Casuarina and mixed plantation site (Bashbaria); B, Sonneretia apetala site (Bogachattar); 0°, along N; 90°, perpendicular to N.

Source: Station’s data collected from Bangladesh Meteorological Department, 2012.

Wind speed reduction by barren coast

At OE of barren coast, minimum wind speed reduction was at 1st observation (1.40%) while maximum at 24th observation (37.60%), respectively. On the other hand, at IE of barren coast, minimum wind reduction was at 1st observation (7.00%), while maximum at 5th observation (50.58%) (Table 3; Fig. 2). It was also found that the efficiency of the wind speed reduction was significantly varied with the height of the major tree species in this area.

 Table 3. Wind speed reduction by barren coast of Potenga-Muhuri irrigation project coastal belt in Chittagong of Bangladesh

SRGHBV_2019_v35n2_78_t0003.png 이미지

SS, sea shore; OE, outside the embankment; IE, inside the embankment.

Wind speed reduction: 0-20%, very low; 21-40%, low; 41-60%, moderate; 61-80%, high; 81-100%, very high reduction. Different letter indicates the significant difference (p≤0.05) between observations.

SRGHBV_2019_v35n2_78_f0002.png 이미지

Fig. 2. Aerial (left photo) and field view (right photo) of barren coast in Chittagong of Bangladesh.

Wind speed reduction by plantation coast

In case of plantation, wind speed reduction efficiency was significantly varied in plantation coast. The study found that the minimum wind speed reduction was at 6th sampling station, (28.74% and 39.57%) whereas maximum wind speed reduction was at 22th sampling station (82.89% and 95.72%) for OE and IE, respectively (Table 4; Fig. 3). It was clearly seen that the scale of wind speed reduction was significantly deviated due to the height and density of the different tree species planted in this coast.

Table 4. Wind speed reduction by plantation coast in Potenga-Muhuri irrigation project coastal belt in Chittagong of Bangladesh

SRGHBV_2019_v35n2_78_t0005.png 이미지

Table 4. Continued

SRGHBV_2019_v35n2_78_t0006.png 이미지

SS, sea shore; OE, outside the Embankment; IE, inside the embankment.

0-20%, very low; 21-40%, low; 41-60%, moderate; 61-80%, high; 81-100%, very high reduction. Different letter indicates the significant difference (p ≤0.05) between observations.​​​​​​​

 SRGHBV_2019_v35n2_78_f0003.png 이미지

Fig. 3. Aerial (left photo) and field view (right photo) of plantation in the Chittagong Coastal belt of Bangladesh.

Wind speed reduction by ship breaking yard coast

In comparison with barren coast and plantation coast, the wind speed reduction efficiency in ship breaking yard coast was different. In case of ship breaking yard affected coast, the study revealed that maximum wind speed reduction (41.26% for OE and 47.40% for IE) was observed at 11th sampling station whereas the minimum was observed at 8th sampling station (24.90% for OE) and 10th sampling station (35.01% for IE) (Table 5).

Table 5. Wind speed reduction at ship breaking yard coast of Chittagong coastal belt in Bangladesh

SRGHBV_2019_v35n2_78_t0004.png 이미지

SS, sea shore; OE, outside the embankment; IE, inside the embankment.

0-20%, very low; 21-40%, low; 41-60%, moderate; 61-80%, high; 81-100%, very high reduction. Different letter indicates the significant difference (p≤0.05) between observation.​​​​​​​

In a comparative way, the findings of this study indicates that wind speed reduction for both OE and IE in coast plantation sampling stations (moderate to very high) was significantly higher than barren coast stations (very low to moderate), and ship breaking yard affected coast (low to moderate).

Tree Species-specific wind speed reduction

Wind speed reduction efficiency varies in tree species to species. The study found that, in case of Casuarina equisetifolia, wind speed decreased gradually up to 15 H, and then lightly increased to 30 H. The maximum wind speed reduction was at 10 H and 15 H (30.62%) whereas the minimum was at 30H (0.51%) (Fig. 4). On the other hand, in mixed plantation, wind speed decreased up to 5H in windward side and then increased gradually. Maximum reduction was at 5H (25.20%) while the minimum was at 30H (0.07%) (Fig. 5). On the other hand, in case of Sonneretia apetala, wind speed decreased up to 5 H, and the maximum reduction was at 10 H. Interestingly, at 30 H it exceeds the leeward side speed (Fig. 6).

SRGHBV_2019_v35n2_78_f0004.png 이미지

Fig. 4. Wind speed reduction efficiency by 6 year-old Casuarina (Height = 5.49 m (H), width=20.12 m and density=2000 no./ha) in the Potenga-Muhuri Irrigation Project in Chittagong Coast, Bangladesh.

SRGHBV_2019_v35n2_78_f0005.png 이미지

Fig. 5. Wind speed reduction efficiency by 6 year-old mixed plantation (Height =4.57 m (H), width=30.48 m and density=2500 numbers/ha) in the Potenga-Muhuri Irrigation Project in Chittagong Coast, Bangladesh.​​​​​​​

 SRGHBV_2019_v35n2_78_f0006.png 이미지

Fig. 6. Wind speed reduction efficiency by 6-year old Sonneretia apetala with Height =6.1 m (H), width=15.24 m and density=2000 no./ha.

Discussion

Wind speed in Potenga-Muhuri Irrigation Project Coastal Belt was significantly varied in different land-uses. The study found that average maximum wind speed was 20.23 km/hr at Potenga station which was second highest among four stations because of its proximity to the sea.

Similarly, average maximum wind speed at Sea shore (SS) of the belt was slightly higher than Potenga station because of the same reason. In case of wind orientation, Potenga and Ambagan stations had 18.81 km/hr and 18.94 km/hr, respectively was higher than Sitakuna and Maijdee. The main reason of such result was wind first hit at previous stations and after that due to turbulence effect the degree of orientation reduced.

On the other hand, in barren coast, wind speed reduction was lowest (1.4%) at 1st observation due to short width of coast and highest (37.60%) was at 24th observation due to long width of coast for OE. For IE, highest (50.58%) wind speed reduction was at 5th observation and lowest (7%) was at 1st observation due to the variation of embankment plantation height (Fig. 7), width and density. Previous studies reported that the optical porosity (a promising alternative to porosity) of a narrow shelterbelt is closely related to the minimum leeward wind speed (Tuzet and Wilson 2007).

 SRGHBV_2019_v35n2_78_f0007.png 이미지

Fig. 7. A well developed embankment plantation at Sadar Forest Range in the Chittagong Coast of Bangladesh.

In plantation coast in the study area, wind speed reduction was lowest (28.74% for OE and 39.57% for IE) at 6th observation and highest (82.89% for OE and 95.72% for IE) was at 22th observation was caused due to variation in plantation width (0.67 km to 2.90 km). Brang et al. (2001) also found the same result (90%) for wind shield of ＜40% porosity and it reduced up to 10 times height of open coast. In case of ship breaking yard coast (Fig. 8), wind speed reduction varied significantly due to variation in homestead structure pattern and homestead wind breakers i.e. planting of wind tolerant tree species. It was also showed that wind speed significantly reduced at from SS. Previous work also found that shelter forests with intermediate densities had the optimal shelter effect (Zeng et al. 2010).

SRGHBV_2019_v35n2_78_f0008.png 이미지

Fig. 8. Aerial view of ship breaking yard in Chittagong coast, (left photo) and major wind resilient tree species in the embankment (right photo) along the coast of Chittagong in Bangladesh .

A 6-year old Casuarina equisetifolia mono-plantation with average height of 5.47 m, average width of 20.12 m and average density of 2,000 stocks/ha can keep reduced wind speed up to 30 H windward side with maximum reduction (31%) at 10 H. On the other hand, a 6-year mixed plantation consisting of Albizia saman (Raintree), Acacia auriculiformis (Akasmoni), Acacia nilotica (Babla), Pongamia pinnata (Kerong) and Erithrina spp. (Mandar), Terminalia catappa (Katbadam). With average height of 4.57 m, average width of 30.48 m and average density of 2500 stocks/ha can keep reduced wind speed up to 30 H windward side with maximum reduction 42% at 5 H. Similarly, a six-year-old mangrove forest of 1.5 km width will reduce 1 m high waves at the open sea and 0.05 m at the coast of India (Mazda et al. 1997).

A Sonneretia apetala mono plantation with average height of 6.09 m, average width of 15.24 m and average density of 2,000 stocks/ha can keep reduced wind speed up to 25 H windward side with maximum reduction of 37% at 5 H. Koh et al. (2010) found that a bibosoop plantation reduces valley wind speed and evaporation in a traditional agricultural landscape, thus contributing to water conservation in the leeward paddy fields during spring, which is a dry season in Korea. However, Im et al. (2009) showed that horizontal wind speed decreased under a height of the tree with increasing maximum leaf area density. Mangroves can reduce the height of wind and swell waves over relatively short distances: wave height can be reduced by between 13 and 66% over 100 m of mangroves (McIvor et al. 2012).

Mangroves have also been observed to mitigate the recent tsunami effects in other places. In Indonesia, the epicenter of the tsunami was closer to Simeuleu Island; however, the death toll on this island was significantly low because of presence of very good mangroves there. This country has planned to revive its coastal defenses, earmarking some 600,000 ha of mangroves across the country, which had lost 30% of its mangrove forest cover over the past several decades. The dense growth of mangroves in thousands of kilometers of Sundarbans saved West Bengal (India) and Bangladesh from the killer impact of tsunami. In Thailand, the island chain of Surin off the west coast escaped heavy destruction because the ring of coral reefs and mangroves that surround the island helped to break the lethal power of the tsunami (Koh et al. 2010). Harada et al. (2002) conducted a hydraulic experiment to study the tsunami reduction effect of the coastal permeable structures using different models mangroves, coastal forest, wave dissipating block, rock breakwater and houses. This work revealed that mangroves are effective as concrete seawall structures for reduction of tsunami effect on house damage behind the forest. Therefore, coastal plantation has a great influence on wind speed reduction from the tidal surge, tsunami and cyclone.

Conclusion

Potenga-Muhuri Irrigation Project Coast Belt in Chittagong plays an inevitable role in coastal protection in Bangladesh. Consequently, this study was conducted to assess the wind speed reduction efficiency through direct field measurements. The results shows that, in case of coast, fifty percent of the total forest belt especially in southern side is barren or very poor which acts as a natural barrier against the extreme events. There are several reasons of failure of raising plantation in that area. Some are natural such as high tidal frequency, salt spray, erosion, and others are anthropogenic such as encroachment followed by aquaculture, farming, grazing, illegal removal of trees, making ship breaking yard. In case of embankment, there are also encroachments by fishermen who live in slums of the southern part of the coast, intensive cropping on outer slopes in the middle part, disappearance by ship breaking yard, illegal removal of trees, damages by erosion and flood, are notable. Despite of these challenges, some areas are well covered by plantations and reduce the wind speed in absence of natural forest in the Chittagong coast. The study also reveals that coastal forest significantly reduces wind speed from sea shore (SS) to inland. A forest belt with mixed plantation of tree species named Sonneretia apetala, Avecennia officinalis, Excocaria agallocha and Cereiops decandra trees and with average height of 9.32 m, width of 2.9 km and 500 stocks/ha is quite enough to reduce wind speed up to 95% of its sea shore wind to in land. It also found that Casuarina equisetifolia is more efficient in wind speed reduction than other mangrove species. As the study area so long forest belt (81 km) and the embankment was so muddy and broken in some places, it was really difficult to take measurements more intensively. Besides, short time period of the wind speed measurement, and so seasonal variations assessment was limitation of this study. Despite of all these limitations, we suggest that relocation of slums from the embankment, awareness building among the nearest community about the role of forest on extreme events protection, planting of mainland wind breakers such as Cocos nucifera, Borassus flabilifer, Phoenix sylvestris etc. in well-established coast, and extensive embankment plantation by the Forest Department under the Social Forestry Programme could help for formulating better wind speed reduction strategy in Bangladesh. However further scientific investigation on a micro-scale coastal forest belt in Bangladesh could substantially add value in the coastal disaster risk management. In this connection, a year-long experiment research might be helpful. Besides, the efficiency off the wind speed reduction during the extreme weather events and a follow-up study on post-disaster impact reduction will also be need to examine to assess the co-benefits of coastal communities and coastal ecosystem of Bangladesh.

References

  1. Ahmed GU. 1999. Decision Analysis For Bangladesh Coastal Affoliestation. MS thesis. University of Toronto, Toronto, Canada.
  2. Aziz A. 2010. Coastal and Marine Plant Resources of Bangladesh: Management and Exploitation. In: Annual Botanical Conference 2009; Chittagong, Bangladesh; January 9-10, 2010.
  3. Brandle JR, Hodges L, Tyndal J, Sudmeyer RA. 2000. Windbreak practices. In: North American agroforestry: an integrated science and practice (Garrett HE, Rietveld WJ, Fisher RF, eds). American Society of Agronomy, Madison, 402 pp.
  4. Brang P, Schonenberger W, Ott E, Gardner B. 2001. Forests as Protection from Natural Hazards. In: The Forests Handbook: Applying Forest Science for Sustainable Management, Volume 2 (Evans J, ed). John Wiley & Sons, Chichester.
  5. Chowdhury SZ. 1982. Coastal afforestation in Bangladesh. In: Bangladesh National Conference on Forestry; Dhaka, Bangladesh; Jun 21-26, 1982.
  6. Christensen B. 1983. Mangroves: what are they worth? Unasylva 35: 2-15.
  7. Das S, Crepin AS. 2013. Mangroves can provide protection against wind damage during Storms. Estuar Coast Shelf Sci 134: 98-107. https://doi.org/10.1016/j.ecss.2013.09.021
  8. de Zoysa M. 2008. Casuarina Coastal forest shelterbelts in Hambantota City, Sri Lanka: assessment of impacts. Small Scale For 7: 17-27. https://doi.org/10.1007/s11842-008-9038-2
  9. Drigo R, Latif MA, Chowdhury JA, Shaheduzzaman M. 1987. The maturing mangrove plantations of the coastal afforestation project. FAD/UNDP/BGD/85/085, Dhaka.
  10. Government of Bangladesh. 2008. Cyclone Sidr in Bangladesh: Damage, loss, and needs assessment for disaster recovery and reconstruction. Economic Relations Division, Dhaka.
  11. Harada K, Imamura F, Hiraishi T. 2002. Experimental study on the effect in reducing tsunami by the coastal permeable structures. In: The Twelfth International Offshore and Polar Engineering Conference; Kitakyushu, Japan; May 26-31, 2002.
  12. Im S, Lee SH, Kim D, Hong Y. 2009. Numerical simulation of the wind speed reduction by coastal forest belts. J Korean Environ Res Tech 12: 98-105.
  13. Islam M. 2007. Coastal forest rehabilitation and management in Bangladesh. In: Proceedings of the workshop on coastal forest rehabilitation and management in Asian tsunami-affected countries; Bangkok, Thailand; September 26, 2006.
  14. Koh I, Kim S, Lee D. 2010. Effects of bibosoop plantation on wind speed, humidity, and evaporation in a traditional agricultural landscape of Korea: field measurements and modeling. Agric Ecosyst Environ 135: 294-303. https://doi.org/10.1016/j.agee.2009.10.008
  15. Lee KH, Ehsani R, Castle WS. 2010. A laser scanning system for estimating wind velocity reduction through tree windbreaks. Comput Electron Agric 73: 1-6. https://doi.org/10.1016/j.compag.2010.03.007
  16. Mazda Y, Magi M, Kogo M, Hong PN. 1997. Mangroves as a coastal protection from waves in the Tong King delta, Vietnam. Mangroves Salt Marshes 1: 127-135. https://doi.org/10.1023/A:1009928003700
  17. McIvor AL, Moller I, Spencer T, Spalding M. 2012. Reduction of Wind and Swell Waves by Mangroves. http://www.naturalcoastalprotection.org/documents/reduction-of-wind-and-swellwavesby-mangroves. Accessed 20 July 2016.
  18. Ministry of Environment and Forests. 2009. Bangladesh Climate Change Strategy and Action Plan, 2009. Ministry of Environment and Forests, Government of the People's Republic of Bangladesh, Dhaka, 76 pp.
  19. Quadir DA, Iqbal A. 2008. Tropical Cyclones: Impact on Coastal Livelihoods. IUCN Bangladesh Country Office, Dhaka.
  20. Saenger P, Siddiqi NA. 1993. Land from the sea: The mangrove afforestation program of Bangladesh. Ocean Coastal Manag 20: 23-39. https://doi.org/10.1016/0964-5691(93)90011-M
  21. Santiago JL, Martin F, Cuerva A, Bezdenejnykh N, Sanz-Andres A. 2007. Experimental and numerical study of wind flow behind windbreaks. Atmos Environ 41: 6406-6420. https://doi.org/10.1016/j.atmosenv.2007.01.014
  22. Takle ES, Chan TC, Wu X. 2006. The Role of Coastal Forests and Trees for Protecting against Wind and Salt Spray. In: Regional Technical Workshop; Khao Lak, Thailand; August 28-31, 2006.
  23. Torita H, Satou H. 2007. Relationship between shelterbelt structure and mean wind reduction. Agric For Meteorol 145: 186-194. https://doi.org/10.1016/j.agrformet.2007.04.018
  24. Tuzet A, Wilson JD. 2007. Measured winds about a thick hedge. Agric For Meteorol 145: 195-205. https://doi.org/10.1016/j.agrformet.2007.04.013
  25. Vigiak O, Sterk G, Warren A, Hagen LJ. 2003. Spatial modeling of wind speed around windbreaks. CATENA 52: 273-288. https://doi.org/10.1016/S0341-8162(03)00018-3
  26. Wang H, Takle ES. 1996. On shelter efficiency of shelterbelts in oblique wind. Agric For Meteorol 81: 95-117. https://doi.org/10.1016/0168-1923(95)02311-9
  27. Wang H, Takle ES. 1997. Model-simulated influences of shelterbelt shape on wind-sheltering efficiency. J Appl Meteorol 36: 695-704. https://doi.org/10.1175/1520-0450-36.6.695
  28. Zeng H, Garcia-Gonzalo J, Peltola H, Kellomaki S. 2010. The effects of forest structure on the risk of wind damage at a landscape level in a boreal forest ecosystem. Ann For Sci 67: 111. https://doi.org/10.1051/forest/2009090
  29. Zhou XH, Brandle JR, Mize CW, Takle ES. 2005. Three-dimensional aerodynamic structure of a tree shelterbelt: definition, characterization and working models. Agrofor Syst 63: 133-147. https://doi.org/10.1007/s10457-004-3147-5
  30. Zhu J, Gonda Y, Matsuzaki T, Yamamoto M. 2003. Modeling relative wind speed by optical stratification porosity within the canopy of a coastal protective forest at different stem densities. Silva Fenn 37: 189-204.
  31. Zhu J, Matsuzaki T, Gonda Y, Sakioka K, Yamamoto M. 2000. Windspeed in a coastal forest belt of Japanese black pine (Pinus thunbergii Parl.): horizontal wind profile. Bull Faculty Agric 52: 139-156.