TIDAL FLOODING
INSIGHT INTO A UNIQUE PHENOMENON
For this Column Volume’s Insight, the AHA Centre invited a young contributor who was also one of its interns – Eviana Rosida – to develop an interesting and informative article. Evi’s current studies in disaster management see her focusing on the unique occurrence of tidal flooding, upon which she has developed this volume’s Insight article. For the ASEAN region, with a coastline 173,00 km in total length, and nine nations bordering the sea or having maritime zones, the potential for tidal flooding is significant. Increasing population density in coastal areas across the region also increases potential impact, while many high-density areas facing the sea are formed by coastal cities.
ABOUT TIDAL FLOODS
Tidal floods in coastal areas may happen due to the process of rising sea water, tidal waves (different from tsunami), the high flow of river water, or general sea level rises. Naturally, tropical cyclones can also trigger a tidal flood. A tidal flood is a flood due to the tidal process that inundates land/coastal areas that are located lower than the average sea level. Long ocean waves are related to tides, and are characterised by the rhythmic rise and fall of the sea surface after a period of several hours. A rising tide is usually referred to as the flow, while the decreasing tide is called the ebb.
There is also a connection between tides and the sun and moon. Tides are in their highest state when the moon is full or new, and high tidal times at a particular location can be estimated (but not exactly) associated with the position of the moon in the sky. Water at the end of the beach bordering the ocean never stays at a fixed height, but they always move up and down according to the tide cycle. These elements also have an impact on tidal flooding.
THE FORMATION OF TIDAL FLOOD PROCESS
As the tidal process undertakes its vertical movement of sea level, these shallow water waves are produced by the gravitational force of the moon and sun on the ocean. The intensity of the force varies according to the position of the moon, sun and earth, and as a result, large tides see the water (with the help of gravitational forces) flow into low places and fill the space, inundating these lower parts.
Tidal flood can be caused by anthropogenic activities, particularly due to land degradation. Human populations living in coastal areas result in high use of groundwater. This use of ground water that exceeds the limit of the groundwater’s ability to replenish is called exploitation, and can increase vulnerability to inundation due to tidal flooding. Tidal floods have hit several areas in Java, Indonesia for example, as the density of people who live on Java has an impact on land subsidence, with high groundwater exploitation causing water to easily inundate the land. The impact of tidal flood sees bodies of sea water causing damage to asphalt roads, and damage to motorised vehicles and bicycles. In addition, sea water that enters the land (sea water intrusion) causes the groundwater to taste salty, and meaning it cannot be used as raw material for drinking water or for daily needs. Salty groundwater can also have a significant negative effect on farming livelihoods in an inundated region.
TIDAL FLOOD PREVENTION
In the short-term, such events may be prevented by building dikes to withstand the tidal waves of sea water heading to the mainland. More long-term, the effect of tidal flooding can be reduced by planting mangroves. Mangrove forests play an important role as ocean wave breakers, retaining wind speeds, and as a habitat for various flora and fauna. Such biological prevention techniques can also be supported by physical development, such as building wall borders between sea and land to act as a wave breaker. Communities who live in coastal area must also be aware about rising sea levels, and reducing exploitation of groundwater so that land subsidence can be avoided.
MONTHLY DISASTER REVIEW AND OUTLOOK
MARCH 2019 | DISASTER MONITORING & ANALYSIS
(DMA) UNIT, AHA CENTRE
GENERAL OVERVIEW OF MARCH 2019
March ended the first quarter of 2019 continuing the trend of lower disaster occurrences compared to its five-year average. This month registered 61% of its five-year average number of disaster occurrences, similar to the statistics of January 2019. However, the number of affected persons was more than 10 times the average for March, and the number of casualties is more than 13 times more than the previous 5 years on average. These considerable differences were driven by two significant events – the drought in North Cotabato, Philippines and the flooding in Sentani, Indonesia. 60% of this month’s affected population is attributed to the Philippines drought, particularly due to the drought’s extensive geographic coverage. On the other hand, 92% of this month’s casualties resulted from the flooding and landslide in Sentani, Indonesia. The primary factor for these figures can be attributed to the timing of the flash flood, which happened at night while most of the residents were sleeping in their homes. This highlights the importance of availability, accessibility, and utilisation of early warning information to drive early action.
Geophysical disasters decreased in March compared to the previous 2 months, with only 23 earthquakes of magnitude 5.0 and above recorded in the region. Of these recorded earthquakes, only one resulted in loss of life. A shallow earthquake with magnitude 5.4 struck north of Selong City in East Lombok Regency, Indonesia. This resulted in damage and collapse of structures in the area, as well as falling rocks and debris at the nearby Tiu Kelep Waterfall in North Lombok Regency, which resulted in the deaths of two tourists visiting the site. This highlights the nature and need for multi-disciplinary and cross-cutting approaches in disaster management
SEASONAL OUTLOOK
The ASEAN Specialised Meteorological Centre reports the end of the Northeast Monsoon, and that onset of the inter-monsoon period is taking place. This is the transition phase between the Northeast and Southwest Monsoons, which is characterised by increased occurrence of scattered rain showers in the region. While seasonal forecast models point to a general increase in rainfall frequency, and a geographic expansion of rain showers, precipitation on the other hand ranges from normal in the Philippines to below-normal in eastern Indonesia and the northern ASEAN region. While the amount of rainfall may not be considerably large, the increase in exposure may still trigger flooding and rain-induced landslides.
Statistically, large-scale disasters that require regional-level response occur during the second half of the year. At the end of 2019’s first quarter, the AHA Centre is wrapping up its preparatory activities for emergency response and other events. This includes the updating and preparation of Common Operational Datasets, 11th ASEAN-ERAT Induction Course, the preparation for the launch of the DELSA satellite warehouses and many more. Activities such as these help prepare the AHA Centre, and the region, to respond to disaster whenever and wherever it may strike.
Data Sources: ASEAN Disaster Information Network, ASEAN Specialised Meteorological Centre
Written by : Lawrence Anthony Dimailig
DISCLAIMER
Disclaimer: AHA Centre’s estimation is based on data and information shared by National Disaster Management Organisations (NDMOs) and other relevant agencies from ASEAN Member States, international organisations and news agencies. Further information on each recorded-significant disaster, description and detail of data and information are available at: http://adinet.ahacentre.org/reports.
THE LAUNCH OF ARMOR FIRST EDITION
The ASEAN Risk Monitor and Disaster Management Review (ARMOR) is the AHA Centre’s newest information publication – a journal that aims to combine science, policy recommendations, and review of actual practices in disaster management. ARMOR’s development is a primary element of the AHA Centre’s efforts to increase the ASEAN region’s knowledge and skills within the global disaster management field, with the first edition published during March 2019. To celebrate this significant achievement, the AHA Centre held ARMOR’s launching event on the 20th of March in Jakarta, Indonesia.
A key aim of ARMOR – is to bridge the gap between science and decision-making in disaster management, with the launch event opening discussions between scientists and decision-makers who were in attendance. The event was officially opened by the Deputy Secretary – General (DSG) of ASEAN for Community and Corporate Affairs – H.E. AKP Mochtan, the Ambassador of the United Kingdom to Indonesia and Timor Leste – H.E. Moazzam Malik, and the AHA Centre’s Executive Director – Ms. Adelina Kamal. Overall, over 100 guests attended the event, including representatives from ASEAN Member States, ASEAN Dialogue Partners, the British Embassy in Jakarta, senior officials of the Indonesian government, a range of AHA Centre partner organisations, academic and scientific community and journalists.
The importance of ARMOR for disaster management in the ASEAN region was reflected by DSG AKP Mochtan in his speech, in which he not only congratulated the AHA Centre for its work on the publication, but also highlighted the functionality of the publication for regional disaster managers and decision-makers.“I would like to congratulate the AHA Centre for its tremendous work in providing a critical platform to bridge science and decision making in the region. The launch of ARMOR is an auspicious critical step forward to building knowledge in the ASEAN community and a valuable opportunity for ASEAN to re-examine our evidence-based decision-making processes. As one of the most highly vulnerable regions to catastrophic disasters, ASEAN has no other alternative but to work toward institutionalising resilience among its communities and peoples.”
During the event, sections from the 10 chapters of ARMOR’s first edition were also discussed by regional disaster management professionals who contributed to the writing, including Dr. Mizan Bisri of the United Nations University Institute for the Advanced Study of Sustainability and Mr. Lawrence Anthony Dimailig of the AHA Centre. The discussion panel – moderated by Said Faisal, the former Executive Director of the AHA Centre who also served as a member of the Board of Editors of ARMOR – gained significant insights and feedback from guest experts such as Dr. Allistair Cook from the Rajaratnam School of International Studies in Singapore, and Mr. Ray Shirkhodai, the Executive Director of the Pacific Disaster Center based in Hawaii.
The success of the launching, and importance of ARMOR overall was reaffirmed by Executive Director of the AHA Centre, Ms. Adelina Kamal during her speech in which she stated that “ARMOR aims to put science at the centre of decision-making process. We are very pleased to launch ARMOR, and hope that the report will be beneficial for our stakeholders to address disaster management across the region”. Ms. Kamal also expressed gratitude to all those involved, reminding all in attendance that “the resources required to develop the ARMOR report are not those of the AHA Centre’s alone, but from the active contribution and participation of the authors, reviewers, editors, and partners of the AHA Centre”.
Written by: Wiliam Shea | Photo : AHA Centre
PROF. DR. KUNTORO MANGKUSUBROTO
Prof. Dr. Kuntoro Mangkusubroto is one of Indonesia’s and ASEAN’s leading figures on disaster recovery and reconstruction. With a deep background forged through a variety of governance and private business roles focused towards energy and natural resources, Dr. Mangkusubroto is also the founder of the School of Business and Management of the Bandung Institute of Technology (ITB). His leadership as the head of the Aceh-Nias Rehabilitation and Reconstruction Agency from in 2005-2009 – which saw him oversee post-tsunami reconstruction and utilisation of local and international assistance to rebuild the shattered region – elevated Dr. Mangkusubroto to become one of the region’s most renowned leaders in disaster management.
Dr. Mangkusubroto’s success leading post-tsunami reconstruction efforts has seen him become a go-to resource in other ASEAN disaster response and recovery efforts – being invited to engage in disasters across ASEAN Member States including Myanmar and the Philippines, as well as international efforts in Nepal and Japan. During 2018’s AHA Centre Executive (ACE) Programme’s Leaders Talk series, participants had the opportunity to learn about the key concepts and integral elements of strong leadership in disaster recovery from Dr. Mangkusubroto himself. Central to Dr. Mangkusubroto’s message was the importance of trust and integrity of ASEAN leaders in disaster management and coordination.
To gain this trust, Dr. Mangkusubroto says, leaders must be able to approach key players and parties to ensure efficiency in logistics and other disaster management processes. He emphasises that knowing who to approach and what to say is key to overcoming the variety of obstacles that can arise during a disaster response. It is through these approaches and the conveying of succinct and clear information that shows one’s integrity, and with this integrity the trust is then strengthened. Dr. Mangkusubroto also highlights the importance of understanding specific contexts and cultures of communities across the region, and that leaders must be prepared to recognise and, importantly, overcome issues for better results for the people as a whole.
“As a leader, people will come to you continuously – they may be angry, sad or unstable due to their losses”, he said. “Just let them release, listen to them, and just give them your sympathy, as once you’ve finished your work, they’ll realise you are serious.” .
To gain this trust, Dr. Mangkusubroto says that leaders must be able to approach key players and parties to ensure efficiency in logistics and other disaster processes. He emphasises that knowing who to approach and what to say is key to overcoming the variety of obstacles that can arise during a disaster response. It is through these approaches and the conveying of succinct and clear information that shows ones integrity, and with this integrity the trust is then strengthened. Mr. Mangkusubroto also highlights the importance of understanding specific contexts and cultures of communities across the region, and that leaders must be prepared to recognise and, importantly, overcome issues for better results for the people as a whole.
Recalling the experiences from the huge reconstruction efforts after the Indian Ocean Tsunami in Aceh, Dr. Mangkusubroto highlights the importance of remaining calm and focused during the midst of high emotions and traumatised communities. “As a leader, people will come to you continuously – they may be angry, sad or unstable due to their losses”, he said. “Just let them release, listen to them, and just give them your sympathy, as once you’ve finished your work, they’ll realise you are serious”. These are just some of the challenges faced by disaster managers and leaders in the field, and overcoming these calmly and reasonably are a big part of what regional leaders must aim to achieve.
After discussions on a range of contexts and experiences faced by leaders in disaster management, Dr. Mangkusubroto concludes on the key elements of efficient and effective disaster management leaders – particularly when in the field in the period after large disasters strike. He emphasises the importance of coordination and communication, whether with governments, local and international responders, logistics providers and the affected communities themselves. He highlights that all parties are there to help and support in their own way, and it is up to the leaders to ensure all parties come together to achieve the greatest results. Dr. Mangkusubroto insists that regardless of the mix of contexts, cultures or political influences at play, the best outcomes can and must be achieved for an effective and sustainable recovery and reconstruction phase. And this, he reminds us, is the key role of ASEAN leaders on disaster management.
Written by : William Shea | Photo : AHA Centre