Experimental study of tsunami bore induced forces on vertical seawall

Field surveys of the 2011 Tohoku Tsunami reported massive failures of many seawalls and coastal barriers. The massive damages are vivid evidence that there are flaws in the design of seawalls and barriers. With this as the background, a sequence of laboratory experiments using dam-break waves was performed to simulate the interactions between the tsunami-like bore flow and vertical seawall as well as to measure the bore-induced pressures and to estimate forces exerted on the vertical seawall model. The experimental result revealed that the maximum pressure (approximately 8 kPa) exerted on the vertical seawall was measured at the lowest pressure sensor location. Experimental data were used to re-examine the relevant empirical formulae found in the literature. The obtained results could be useful for calibrating mathematical and numerical models as well as for future research concerning the design of tsunami barriers

Performance of Hybrid Rice Husk and Kapok Fiber as Alternative Liner Materials in Landfill

Generation of waste from agricultural activities like rice husk (RH) and kapok fiber (KF) is on the rise annually. Some of the arising issues are landfill limitation and air pollution because of burning activities. This paper presented a potential application of agricultural waste as an alternative material in landfill. A series of standard tests were conducted such as hydraulic conductivity test (falling head method), batch adsorption test (COD, TSS and heavy metals testing). These tests were conducted in the ratio of 1:1 and 1:2 of hybrid RH:KF. The results yielded that the hydraulic conductivity of the hybrid RH:KF in the ratio of 1:1 was lesser than 10-9 m/s, satisfying the requirement of landfill liner. The hybrid arrangement (RH:KF) for 1:1 ratio as adsorption media was able to reduce at least 45% of the bulk parameter (COD) whereas for 1:2, ratio, about 43.5% of heavy metal (Zn) was reduced in leachate. The proposed hybrid arrangement (RH:KF) is a green material for the landfill (bulk parameters and heavy metal adsorption capacity) that improves landfill workability, minimizing manpower on site and cost

Adolescent to Adolescent Transformation Program- Nurturing, Enhancing and Promoting Adolescents’ Healthy Habit (ATAP-NEPAH): Curbing Social Problems Among Adolescents in Kelantan Through Peer-To-Peer Health Education

The objectives of ATAP-NEPAH are to enhance and nurture healthy habits among adolescents as well as to empower adolescents in inculcating these healthy habits among them. Health education through peer-to-peer approach is used to instill the knowledge on important areas such as sexual and reproductive health, smoking, substance abuse, illegal street racing (rempit) and mental health. Specific modules were developed by experts (lecturers) in multidisciplinary fields in collaboration with Malaysian Association for Adolescent Health (MAAH), National Population and Family Development Board (NPFDB), Reproductive Health Association of Kelantan (REHAK) and Rhaudatus Sakinah Kelantan. The trained Medical Students Facilitator Team (MSFT) of USM became trainers to secondary one school students. The selected school students were trained by the medical students to become peer educators to their juniors and peers. There was improvement in the readiness level of peer educators, knowledge and attitude towards healthy habits and risky behaviors of other school students after the intervention

Overtopping scour due to tsunami bore: laboratory study

Tsunami wave is one of the most serious threats to lives and activities, particularly in coastal cities within 100 m height from the mean sea level. Construction of coastal defense structures, such as seawalls and breakwaters, is the most popular measure adopted by engineers for protection from sea waves, including tsunamis, and mitigation of their effects. Many researchers determined through their post-tsunamis field studies that the scour at the landward toe of coastal defense structures induced by tsunami overtopping is the predominant cause of structural failures. İn the present study, a series of laboratory experiments was conducted at National Hydraulic Research Institute of Malaysia to investigate the scour profile at the landward toe of a vertical seawall induced by tsunami bore overtopping vertical seawall and examine the influence of breakwater and bore characteristics on the induced scour depth and length. The experiments showed that the breakwater in low initial depth conditions was more effective in reducing bore velocity and scour depth at the landward toe of the seawall than that in high initial depth conditions. Moreover, a strong positive relationship was confirmed between the Froude number of the overtopping flow and the induced scour depth and length

Physical Modeling of Landward Scour Due to Tsunami Bore Overtopping Seawall

many of the post tsunami field surveys which conducted by researchers revealed that, the failure due to scour at the landward toe of the seawall due to overtopping of tsunami wave forms one of the important types of coastal defence structures failure and constitutes one of the biggest threats to their structural performance. This study was intended to investigates the scour profile induced by tsunami bores at the landward toe of the vertical seawall and to discuss the effects of the parameters; tide level, incident bore Froude number Fb, incident bore height Hb, overtopping flow Froude number Fo, and overtopping flow depth Ho on the maximum scour depth induced at the landward toe of the seawall. A set of laboratory experiments were conducted at National Hydraulic Research Institute of Malaysia (NAHRIM) with the tichnique of dam break to generate the bore like tsunami. The experiments showed that the initial water level upstream of the seawall has a significant effect on the scour profile and there is a strong negative relationship exists with Froude number of the incident bore and a strong positive relationship exists with Froude number of the overtopping flow depth above the crest of the seawall

Physical Modeling of Landward Scour Due to Tsunami Bore Overtopping Seawall

many of the post tsunami field surveys which conducted by researchers revealed that, the failure due to scour at the landward toe of the seawall due to overtopping of tsunami wave forms one of the important types of coastal defence structures failure and constitutes one of the biggest threats to their structural performance. This study was intended to investigates the scour profile induced by tsunami bores at the landward toe of the vertical seawall and to discuss the effects of the parameters; tide level, incident bore Froude number Fb, incident bore height Hb, overtopping flow Froude number Fo, and overtopping flow depth Ho on the maximum scour depth induced at the landward toe of the seawall. A set of laboratory experiments were conducted at National Hydraulic Research Institute of Malaysia (NAHRIM) with the tichnique of dam break to generate the bore like tsunami. The experiments showed that the initial water level upstream of the seawall has a significant effect on the scour profile and there is a strong negative relationship exists with Froude number of the incident bore and a strong positive relationship exists with Froude number of the overtopping flow depth above the crest of the seawall

The impact of climate change on coastal erosion in Southeast Asia and the compelling need to establish robust adaptation strategies

Climate change alters the climate condition and ocean environment, leading to accelerated coastal erosion and a shift in the coastline shape. From previous studies, Southeast Asia's coastal region is suffering from severe coastal erosion. It is most sensitive and vulnerable to climate change, has broad and densely populated coastlines, and is under ecological pressure. Efforts to systematically review these studies are still insufficient despite many studies on the climate change linked to coastal erosion, the correlation between coastal erosion and coastal communities, and the adaptative measures to address these issues and their effectiveness in Southeast Asia. Therefore, by analyzing the existing literature, the purpose of this review was to bridge the knowledge gap and identify the link between climate change and coastal erosion in Southeast Asia in terms of sea-level rise, storm surge, and monsoon patterns. The RepOrting standards for Systematic Evidence Syntheses (ROSES) guided the study protocol, including articles from the Scopus and Dimension databases. There were five main themes considered: 1) climate change impact, 2) contributing factors to coastal erosion, 3) coastal erosion impact on coastal communities, 4) adaptation measure and 5) effectiveness of adaptation measure using thematical analysis. Subsequently, nine sub-themes were produced from the themes. Generally, in Southeast Asia, coastal erosion was reflected by the rising sea level. Throughout reviewing past literature, an interesting result was explored. Storm surges also had the potential to affect coastal erosion due to alterations of the atmospheric system and seasonal monsoon as the result of climate change. Meanwhile, an assessment of current erosion control strategies in relation to the relative hydrodynamic trend was required to avoid the failure of defence structures and the resulting danger to coastal communities. Systematically reviewing the existing literature was critical, hence it could significantly contribute to the body of knowledge. It provides valuable information for interested parties, such as authorities, the public, researchers, and environmentalists, while comprehending existing adaptation practices. This kind of review could strategize adaptation and natural resource management in line with coastal communities' needs, abilities, and capabilities in response to environmental and other change forms