Evaluation of Flood Damages Using Principal Component Analysis

Azotea,Marc Sinan B,Necesito,Imee V,Cheong,Tae Sung,Yu,Insang,Jeong,Sangman 한국방재학회 2015 한국방재학회논문집 Vol.15 No.4

한국의 경제성장에도 불구하고 홍수와 같은 자연재해는 여전히 경제적 지위에 타격을 가하고 있으며 태풍에 의해 발생한 홍수피해는 막대한 재산과 인명피해의 원인이 되어왔다. 이와 관련하여 본 연구에서는 홍수피해에 영향을 주는 주요 매개변수를 산정하였으며 시 설의 종류에 따라 구분된 군산시의 485개 시설에 대한 홍수피해액 자료를 활용하였다. 주성분분석을 통하여 홍수피해액, 침수심, 침수 시간, 침수범람면적, 수입, 지가 중 어떤 종류의 매개변수가 각각의 시설에 가장 크게 영향을 미치는지 분석하였다. 주성분분석 결과는 변수들 간의 상관관계와 어떠한 매개변수가 홍수피해액과 연관성이 있는지 나타낸다. 본 연구에서는 주성분을 산정하기 위해 데이터 매트릭스의 고유벡터와 고유치를 활용하였으며 고유벡터와 고유치를 사용한 주거, 상업, 농업시설의 홍수피해 변량 산정 결과, 각각 0.6918, 0.6265, 0.7001으로 산정되었다. 주성분분석의 유의수준이 0.5보다 크거나 -0.5보다 작으면 변수의 상관성이 인정되는데 본 연 구에서는 여러 변수 중 침수심이 가장 상관성이 높은 것으로 나타났다. Despite the growing economy of Korea, natural disasters such as floods are still knocking the economic ladder. The counteractions made by flood disasters that were also induced by typhoons have caused significant damages to properties and human life. In this regard, the searches for the primary parameters that are affecting the flood damage amount were focused in this study. The data used in this study is flood damage from the 485 facilities in Gunsan City which were further divided based on the facility type. It identifies what type of parameter variable namely: flood damage, flood depth, flood duration, inundation area, family income and land price greatly affects or are relevant to each facilities being classified using Principal Component Analysis (PCA). Results from the Prin-cipal Component Analysis (PCA) show the relationship that exists among the variables and that it had narrowed down to which parameter was correlated to flood damage. This paper used the eigenvector and eigenvalue of the data matrix in order to compute the principal component. The result of the total variance in the flood damage of residential, commercial and agricultural facilities using the eigenvector and eigenvalue were calculated to be 0.691, 0.626 and 0.700, respectively. Significant level of Principal Component Analysis greater than 0.5 and less than -0.5 must be attained for relativity variables to exist and as for this study it proves that flood depth was the most significant among the rest.

Structural Behavior Estimation of North Caloocan Doctors Hospital for an Imminent 7.2 Magnitude Earthquake

Azotea. Marc Sinan B,De Luna. Emmanuel M,Tiburcio. Rodelio A. 한국방재학회 2016 Journal of Disaster Management Vol.1 No.3

Natural disasters are considered inevitable. However, the damage of which can be mitigated through proper implementation from countermeasures. In the Philippines it was reported by the Philippine Volcanology and Seismology (PHILVOCS) that an ominous 7.2 magnitude earthquake in the second quarter of 2015 will hit the capital region of the country, Manila. A 25 percent estimated damage is assumed to be incurred throughout the region both from public and private infrastructures. The foresighted event led to the materialization of this study which assesses the stability of one hospital, the North Caloocan Doctors Hospital (NCDH), in case of the said earthquake. Moreover, the conducted research determines the potentiality of the structure for Immediate Occupancy (IO) in accordance with the criteria set by ATC-40, a code which contains standards and specifications that was developed by the state of California for the evaluation of seismic performance of existing buildings. Also, emergence of plastic hinges on the support structures were also checked and evaluated. SAP2000 is a 3D modeling software which creates a scaled representation of the building given the required input parameters for the simulation of a nonlinear pushover analysis of the earthquake event. This was used in this research. After the simulation, results were then compared to ATC-40 for the evaluation of its structural performance level and stability. Both the x and y direction of the structure was observed and it showed that the global displacement produced for x and y are 0.199 meters and 0.145 meters, respectively. However, in order to meet the objectives of the study, standards from ATC-40 for IO in terms of displacement should not exceed a value of 0.166 meters in any direction. The output clearly implies that the x-direction exceeded the given value, therefore making the structure not suitable for the level of performance the researchers wanted. Furthermore, during the pushover analysis, plastic hinges were developed under cases of IO and Life Safety (LS) and non on the Collapse Prevention (CP). This positively signifies that the structure, after the impending earthquake would still be safe and readily accessible for many.

Evaluation of Flood Damages Using Principal Component Analysis

Azotea, Marc Sinan B.,Necesito, Imee V,정태성,유인상,정상만 한국방재학회 2015 한국방재학회논문집 Vol.15 No.4

Despite the growing economy of Korea, natural disasters such as floods are still knocking the economic ladder. The counteractions made by flood disasters that were also induced by typhoons have caused significant damages to properties and human life. In this regard, the searches for the primary parameters that are affecting the flood damage amount were focused in this study. The data used in this study is flood damage from the 485 facilities in Gunsan City which were further divided based on the facility type. It identifies what type of parameter variable namely: flood damage, flood depth, flood duration, inundation area, family income and land price greatly affects or are relevant to each facilities being classified using Principal Component Analysis (PCA). Results from the Principal Component Analysis (PCA) show the relationship that exists among the variables and that it had narrowed down to which parameter was correlated to flood damage. This paper used the eigenvector and eigenvalue of the data matrix in order to compute the principal component. The result of the total variance in the flood damage of residential, commercial and agricultural facilities using the eigenvector and eigenvalue were calculated to be 0.691, 0.626 and 0.700, respectively. Significant level of Principal Component Analysis greater than 0.5 and less than -0.5 must be attained for relativity variables to exist and as for this study it proves that flood depth was the most significant among the rest.

Application of Rapid Earthquake Damage Assessment System (REDAS) for Seismic Risk Estimation

Azotea. Marc Sinan B,Dungca. Gabriel Bautista,Herrera. Odyssey 한국방재학회 2017 Journal of Disaster Management Vol.2 No.3

An earthquake in the Philippines is already an everyday life for the people. Marikina City in Manila is a home to four hundred thousand residents located near a valley fault with a system capable of creating large-scale earthquakes of magnitude 7 or more. Thus, the objective of this study is to assess the possible risk that can be brought about by “The Big One”, a 7.2 earthquake using previous events and surveyed data with the help of the Marikina Research & Planning Division. The importance of this research is that it would greatly help in reducing the effects of earthquake disasters as this presents data of areas which would deal great damage on its geographic location and buildings which are prone to devastation. Moreover, the study aids in the planning and mitigating of the possible consequences of disaster events which would eventually aid in the development of plans for recovery and reconstruction following a disaster. The scope of this research however is only limited to all areas inside Marikina City and would only focus on the seismic assessment for the said area. All the necessary data input required in the study both primary and secondary were obtained from surveys and site inspections for the three barangays in Marikina. All of which are in coordination with the Marikina City Disaster Risk Reduction and Management office and the Philippine Institute of Volcanology and Seismology. The results showed that using that Marikina City is indeed susceptible to ground shaking because of its geographic location and that from the physical damages in terms of floor area, damage with collapse is clearly evident and in terms of buildings damage with no collapse is the most defined. Additionally, for the number of casualties or fatalities, due to the fact the buildings are strong enough to withstand the earthquake hazard, therefore, fewer fatalities are portrayed, and rather slight damages were shown. As for the economic losses an estimated amount of 636,000 US dollars is expected from the aftermath of the earthquake. Therefore, from the outcomes shown, it can be stated that indeed Marikina City is of high seismic risk due to the proximity of it to the fault line and its development within the area. Also, even if casualties are of fewer numbers, complacency is still not an option for the government. Constant monitoring and evaluation is further need to correctly apply and abate the vulnerability of the area when the Big One occurs.

Evaluation of Localized Flood Vulnerability Index through its Components’ Behavioral Trends:

Azotea Marc Sinan B,Tae Sung Cheong,Sang Man Jeong 한국방재학회 2017 Journal of Disaster Management Vol.2 No.2

Natural disasters such as flood increase its frequency of occurrence and have made a toll on the lives of many people. This research focuses and gives its attention on the assessment of a Flood Vulnerability Index (FVI) under a local scale to clearly define its condition through the use of trends from the components of FVI. This also seeks the attention of decision, policy makers and stakeholder for this would locate the soft spots of the flood through the vulnerability index using the components as determinants of those weaknesses. In order to do this research, weights were applied to the indicators and components using the Analytical Hierarchy Process (AHP). Then, calibration and verification using a 10-year data of the municipality of Manito were made to check its robustness and see the trend on its four components namely social, economic, environmental and physical. The FVI values are also standardized having a range of 0 to 1 to determine the vulnerability of an area, where 0 is the least vulnerable and 1 being the highest. The result of the study shows that there was a 0.05 relative or 5% percentage error in the calibration and verification of the FVI under the local scale, making it plausible and reliable. Also, it shows that the vulnerability is indeed time-dependent, so a need to ensure the succeeding years for analysis and evaluation is a must. The result also showed that 3 out of the 4 components obtained a high FVI value (environmental, economic and physical, respectively). Therefore, this research evaluated the FVI of the area and had identified which among the components needs prior attention, so that the government can respond correctly on how to mitigate flood.

Establishing and Assessing a Localized Flood Vulnerability Index in the Philippines:

Azotea Marc Sinan B,Tae Sung Cheong,Sang Man Jeong 한국방재학회 2017 Journal of Disaster Management Vol.2 No.2

Flood, a natural disaster, increases its regularity of incidence and have made a toll on the lives of many people. Legazpi city, the capital of Albay, Philippines, was chosen as the study area for it has been considered as one of the cities that has a progressive economy and is an example set by the United Nations Development Program (UNDP) as an area with high resilience and adaptive capability to disasters such as flood. With this, the study aims to develop a Flood Vulnerability Index (FVI) under a local scale to clearly assess the conditions on a specific level and to know who among the four components (social, economic, environmental and physical) the city is most vulnerable at. Furthermore, it seeks the interest of decision, policy makers and stakeholder for this would locate the soft spots of flood using the components as determinants of those weaknesses. The use indicators to assess and measure the level of harm flood would give to the area was done and a 10 year data was gathered for calibration and verification of this methodology. Moreover, Analytic Hierarchy Process (AHP) was used to obtain the weights and a consistency check was performed for the robustness and credibility of each component and indicator. Additionally, a standard value of 0 to 1 to determine the vulnerability of an area, where 0 is the least vulnerable and 1 being the highest is portrayed to equalize the range for comparison. The result shows that the city has an index value of 0.509, which is under a highly vulnerable to flood scaling. It also shows that it is weakest under the physical and environmental component, thereby increasing the FVI value. Knowing that the city is most vulnerable under these two aspects, decision and policy makers can now plan to make laws and implement structures in order to mitigate flood and its further impacts.

Behavioural Trends of the Components of Flood Vulnerability Index and its Application on a Localized Scale

Azotea. Marc Sinan B.,Cheong. Tae Sung,Jeong. Sangman 한국방재학회 2017 한국방재학회 학술발표대회논문집 Vol.2017 No.-

Comparative Radial Analysis of Philippines’ Local Flood Vulnerability Index

Azotea Marc Sinan,Cheong Tae Sung,Jeong Sang Man 한국방재학회 2017 한국방재학회논문집 Vol.17 No.5

오늘날 인명피해, 경제손실, 가축피해 등을 야기하는 홍수는 국제적 관심사이며, 피해를 저감시키기 위해 꾸준히 노력하고 있다. 또한, 필리핀에서도 홍수는 주요 관심사이며, 홍수취약성 분석을 위해 홍수취약도지수(FVI)분석 방법을 사용하여 취약성분석을 수행하고 있다. 그러나 광범위한 지역에 대해 FVI 분석을 수행하기 때문에 홍수취약지역이 정밀하게 분석되지 않고 있다. 본 연구에서는 소규모 지역에 FVI 방법을 적용하기 위하여 필리핀 Albay지방 다섯 개 지역(1개 도시와 4개 지방지치구)에 대해 취약성을 분석하고, 비교하였다. FVI분석의 요소와 지표를 평가하기 위해 전문가 대상의 설문을 이용한 방법인 AHP 방법을 사용하였다. 과거 10년(2006~2015) 동안의 홍수피해 자료를 수집하여 처음 5개년 자료는 보정, 나머지 5개년 자료는 검증을 위해 사용하였으며, 이를 통해 0에서 1의 범위로 홍수취약성을 표준화하여 ‘매우 낮음’, ‘낮음’, ‘보통’, ‘높음’, ‘매우 높음’으로 구분하였다. 각 구성요소(사회적, 경제적, 환경적, 물리적)에 대한 분석결과, 5개 지역 모두 환경적 요소 및 물리적 요소에 대한 취약성은 ‘매우 높음’으로 평가되었으며, 사회적 요소 및 경제적 요소에 대한 취약성은 ‘보통’에서 ‘높음’으로 평가되었다. 종합적인 FVI 분석결과 Manito 지역의 취약성이 0.632로 홍수에 가장 취약한 것으로 평가 되었으며, Guinobatan, Bacacay, Camalig, Legazpi 지역에서 각각 0.632, 0.576, 0.521, 0.509로 분석되었다. 위의 결과를 통해 소규모 지역에 FVI평가를 진행함으로서 구체적인 홍수취약성 분석이 가능한 것으로 확인되었다. Flood has been a primary concern and one of the global issues today, because it has been knocking down lives, economy, live stocks which people has been striving to protect. In the Philippines, flood is also a big issue and although there is an existing flood vulnerability index (FVI) assessment, vulnerable areas are not accurately identified because it is done on a larger scale basis. In this research an FVI under a smaller scale was used to assess the vulnerability of five areas (one city and four municipalities) in the province of Albay, Philippines. A comparative analysis was also performed to identify which among these five areas are more vulnerable to flooding. Analytical Hierarchy Process (AHP) was used to weigh the indicators and components through the expert decision from surveys made by different professionals. A 10-year data from 2006 to 2015 was collected wherein the first 5 years was used for calibration and the succeeding years was for verification. The outcome is standardized with values ranging from 0 to 1 (extremely low, low, moderate, high and extremely high). Finally, assessment of each components (social, economic, environmental and physical) showed that all five areas are identified to be extremely high vulnerable for both environmental and physical components. While for the social and economic component, the value ranges from moderate to high vulnerability. Manito has the highest overall FVI with a value of 0.655, followed by Guinobatan, Bacacay, Camalig and lastly, Legazpi with values of 0.632, 0.576, 0.521 and 0.509, respectively. Therefore, application of FVI assessment to smaller scale areas provides specific results in identifying the areas which are vulnerable to flooding.

The 4th International Conference on Urban Disaster Reduction(ICUDR) and Earthquake Recovery Experiences

Marc Sinan Azotea 한국방재학회 2016 한국방재학회지 Vol.16 No.6