Application of Principal Component Analysis in the Evaluation of the Damages Incurred by Ondoy and Perpeng’s Lash to Philippines

Necesito, Imee V,유인상,정상만 한국방재학회 2014 한국방재학회논문집 Vol.14 No.4

One of the adverse impacts of climate change is excessive rainfall patterns, most of the time creating flood disasters. Flood disaster isone of the most serious natural hazards for human societies which cause damages to properties as well as loss of human lives thus creatinggreat impacts on the economic status of the state. A country, such as the Philippines, which is bounded by limited funds, is mostlikely to have a public outcry in times of catastrophes like intense floods. This paper examines the impacts of the 2009 Ondoy andPepeng flood as well as used principal component analysis to derive components that were capable of explaining the 79.38% of thetotal variance in the flood damage. Data from the studies funded by the different institutions both local and international were used inorder to evaluate the damages and losses on the economic and social perspective of the country during the said two catastrophicevents.

2013 Monster Typhoon Haiyan and the Anatomy of Disaster in Tacloban, Leyte

Imee V. Necesito,JMicah Lourdes A. Felix,Sangman Jeong 한국방재학회 2014 한국방재학회 학술발표대회논문집 Vol.2014 No.-

Super Typhoon Haiyan which is known as super typhoon Yolanda in the Philippines, the 24th typhoon to hit the country in 2013, is the world’s ‘most devastating typhoon to make a landfall’ in the entire human history. It struck the middle region of the Philippines killing thousands of people and causing billions of pesos worth of economic damages and losses. Tacloban, the capital of the province of Leyte which is approximately 360 miles southeast of Manila and is the largest city in the Eastern Visayas gaining the title of a highly urbanized city, was drastically damaged mainly due to storm surge flooding. The exceptional vulnerability of Tacloban was identified to be due to four reasons: the city’s large population, degree of urbanization, geographical location and last but not the least, its weak coastal areas. Worldwide Fund for Nature (WWF) Philippines assessed the disaster preparedness of 12 cities in the Philippines including Tacloban. Several aspects are to be considered including Tacloban’s environmental and socio-economic exposure as well as its adaptive capacity towards catastrophic threats like Haiyan. This paper aims to provide better visualization on how danger-prone areas like Tacloban should act in anticipation of occurrence of extreme weather events. Development of strategies will also be tackled in relation to the development of disaster response

Semi-parametric Geographically Weighted Regression Modelling for Flood Damage Assessment in Gunsan City, Korea

Imee V. Necesito,Tae Sung Cheong,Insang Yu,Sangman Jeong 한국방재학회 2015 한국방재학회 학술발표대회논문집 Vol.14 No.-

Climate change has been a global issue since the 19th century. The increase in rainfall variability, which covers the increase in the earth’s total precipitation, will definitely lead to frequent and more severe flood disasters. As the damage increases year after year with floods as the most chronic and costly disaster among these hazards, Korea has to improve its technological responses and countermeasures to better visualize the hazards brought about by such disasters. Gunsan City ranked number eight in the country’s most susceptible region to floods. From 2004 to 2013, Korea has experienced a total of 174 flood disasters which were estimated to cost USD 7.32 billion. But reports showed that the total expenditure of the government amounted to 1.4 times the estimated losses and damages and the private companies have spent twice the said estimated amount. To summarize, the post-disaster loss and damage reports showed underestimated values. This study aims to develop a semi-parametric geographically weighted regression which can implement a flood damage estimation model of Gunsan City. The model building process include parameters like flood depth, flood duration, inundated area, family income and land price. The datasets are composed of both untransformed and transformed data (using Box-Cox Method). Both Ordinary Least Squares (OLS) Regression and Geographically Weighted Regression (GWR) were evaluated in this study, but the search for best fit resulted to the use of GWR.

2013 MONSTER TYPHOON: HAIYAN

Imee V. Necesito 한국방재학회 2014 한국방재학회지 Vol.14 No.1

Semi-parametric Geographically Weighted Regression Modelling for Flood Damage Assessment

Imee V. Necesito,Tae Sung Cheong,Insang Yu,Sangman Jeong 한국방재학회 2016 Journal of Disaster Management Vol.1 No.3

Climate change has been a global issue since the 19th century. The increase in rainfall variability, which covers the increase in the earth’s total precipitation, will definitely lead to frequent and more severe flood disasters. As the damage increases year after year with floods as the most costly disaster among these hazards, Korea has to improve its technological responses and countermeasures. This study aims to develop a semi-parametric geographically weighted regression which can estimate a flood damage of Gunsan City. The model include parameters like flood depth, flood damage, flood duration, inundated area, family income and land price. This study collects flood depths, flood duration from GIS based flood inundation map and flood damages of local buildings from damages report collected by local government after flooding on August, 2012 in Gunsan City. Flood damage estimation of residential, commercial and agricultural facilities was done by Ordinary Least Squares and Geographically Weighted Regression using collected data. Considering the building and GIS-based spatial information, flood damage by GWR is more appropriate than OLS.

Development of Multivariate Flood Damage Function for Flood Damage Assessment in Gunsan City, Korea

Imee V. Necesito,Tae Sung Cheong,Insang Yu,Sangman Jeong 한국방재학회 2015 한국방재학회 학술발표대회논문집 Vol.14 No.-

From 2004 to 2013, Korea has experienced a total of 174 flood disasters and has a total estimated cost of USD 7.32 billion. However, reports showed that the total expenditure of the government amounted to 1.4 times the estimated losses and damages and the private companies have spent twice the said estimated amount. To summarize, the post-disaster loss and damage reports showed underestimated values. In this regard, the National Emergency Management Agency (NEMA), the government institution designated to assess and analyze the damages and losses as well as evaluate the disaster risks of the said areas in accordance to their disaster risk management plans, are now developing a new estimating method for damages and losses. This study aims to develop flood damage functions that will estimate the flood damages of Gunsan City based on the building type: residential, commercial and agricultural facilities, by utilizing the Ordinary Least Squares Regression and later on, the Geographically Weighted Regression. The model building process includes flood depth, flood duration, inundated area, family income and land price as the parameter variables. Due to normality issue, the datasets were transformed through Box-Cox Method. Both Ordinary Least Squares (OLS) Regression and Geographically Weighted Regression (GWR) were evaluated in this study, but the search for ‘best fit’ resulted to the use of GWR.

Analysis on Rainwater Harvesting System as a Source of Non-Potable Water for Flood Mitigation in Metro Manila

Imee V. Necesito,Micah Lourdes A. Felix,Lee-Hyung Kim,Tae Sung Cheong,Sangman Jeong 한국습지학회 2013 한국습지학회지 Vol.15 No.2

전 세계 적으로 발생하고 있는 국지성 집중호우, 가뭄, 혹서, 태풍, 해수면 상승 등과 같은 징후는 기후변화가 진행되고 있음을 보여준다. 이러한 기후변화로 인해 일정빈도이상의 과도한 강우가 발생하면 필리핀의 마닐라는 높은 도시화와 홍 수에 취약한 구조 때문에 홍수피해가 빈번하게 발생한다. 마닐라의 홍수조절 기능 및 생활용수 공급은 Angat댐을 통해서 만 관리되기 때문에 홍수방지와 원활한 물공급을 위해 가정용우수저류시설은 최적의 대체자원이 될 수 있다. 가정용우수 저류시설에 의해 공급되는 물은 여과 및 살균과 같은 수처리 과정을 거쳐 식수로 사용될 수 있으며 수처리 과정을 거치 지 않은 잡용수는 세정, 세차, 청소 등의 목적으로 사용할 수 있다. 본 연구에서는 다양한 기후조건을 적용하여 가정용우 수저류시설의 잠재가용량과 잠재가용성을 결정하기 위해 마닐라에 위치한 5개 강우관측소에서 갈수해, 평수해, 강수해로 구분하여 강우자료를 수집하였다. 필리핀은 대부분의 지역이 도시화되어 과도한 강우 발생시 많은 양의 우수가 발생되었 으며 본 연구의 결과를 통해 가정용우수저류시설의 사용은 잡용수의 대체자원으로서 적절한 대안이 될 것으로 판단된다.

Estimation of Sediment Yield Using Total Sediment Yield Formulas and RUSLE

이민형,유인상,Necesito, Imee V,김하룡,정상만 한국방재학회 2014 한국방재학회논문집 Vol.14 No.4

Gyeongan stream, the first tributary of Han River in Korea, flows into Paldang Lake providing potable water to 23 million people livingin the Seoul Metropolitan area. This stream is shallow and discharges small amount of water which adds up to the accumulation offloating matter. The water flowing into the lake worsens the discharge capacity and the water quality of the basin. It also reduces itsstorage capacity, a threat to the water supply function. For these reasons, it is necessary to quantitatively investigate the sediment loadflowing into Paldang Lake from Gyeongan stream to come up with a countermeasure. In this study, a quasi-sediment rating curve wasdeveloped using the 2008 to 2010 total sediment load. Total sediment load was estimated based on the data of suspended load measuredat Gyeongan stream basin. Taking into account the existing Sediment Delivery Ratio (SDR) equation of soil loss calculated byRevised Universal Soil Loss Equation (RUSLE) and the equation of sediment yield, a comparative analysis between the actual measureddata and the latter was executed. The results showed that the sediment yield calculated using Ackers and White’s total sedimentload equation and Vanoni’s RUSLE by SDR are almost similar with quasi-sediment rating curve. Their relative errors of total sedimentaccording to Ackers and White and Vanoni’s RULSE were calculated to be 6.4%~13.5% and 8.1%~12.0% respectively. Thisindicates the feasibility of estimating sediment yield using Ackers and White’s total sediment load equation and Vanoni’s SDR.

Recent Philippine Flood Disasters: 2009 Typhoon Ondoy and Pepeng

Imee V,Necesito,Insang Yu,Sangman Jeong 한국방재학회 2016 Journal of Disaster Management Vol.1 No.1

Abstract Natural disasters are out of control phenomena that continue to devastate even the most advanced countries in the world. Flood disaster is one of the most serious natural hazards for human societies which cause damages to properties as well as loss of human lives. A country, such as the Philippines, which is bounded by limited funds, is most likely to have a public outcry in times of catastrophes like intense floods. This paper examines the impacts of the 2009 Ondoy and Pepeng flood in view of the Philippines’ productive and social sectors as well as presents a glimpse on the economic conditions of the urban and rural poor communities and how they survived the hazards of the said catastrophes amid limited support from the government and other institutions. Data from the studies funded by the different institutions both local and international were used in order to evaluate the damages and losses on the economic and social perspective of the country during the said two catastrophic events. This assessment, backed up by previous actual observations, will help the government and civil society groups to refine and apply different recovery and reconstruction strategies for the benefit of the entire country. Abstract Natural disasters are out of control phenomena that continue to devastate even the most advanced countries in the world. Flood disaster is one of the most serious natural hazards for human societies which cause damages to properties as well as loss of human lives. A country, such as the Philippines, which is bounded by limited funds, is most likely to have a public outcry in times of catastrophes like intense floods. This paper examines the impacts of the 2009 Ondoy and Pepeng flood in view of the Philippines’ productive and social sectors as well as presents a glimpse on the economic conditions of the urban and rural poor communities and how they survived the hazards of the said catastrophes amid limited support from the government and other institutions. Data from the studies funded by the different institutions both local and international were used in order to evaluate the damages and losses on the economic and social perspective of the country during the said two catastrophic events. This assessment, backed up by previous actual observations, will help the government and civil society groups to refine and apply different recovery and reconstruction strategies for the benefit of the entire country.

Development of Multivariate Flood Damage Function for Flood Damage Assessment in Gunsan City, Korea

Yu Insang,Necesito Imee V,Kim Hayong,Cheong Tae Sung,Jeong Sangman 한국방재학회 2017 한국방재학회논문집 Vol.17 No.2

한국의 경제성장과 재해방재기술 향상에도 불구하고 홍수와 같은 자연재해는 여전히 국민들을 위협하고 있으며 특히, 태풍에 의해 발생한 홍수피해는 막대한 재산과 인명피해의 원인이 되어왔다. 홍수에 의한 피해액을 추정하는 것은 홍수대책마련과 홍수피해를 저감하는데 매우 중요하다. 이와 관련하여 피해 및 손실을 평가 및 분석하고 재해 위험 관리 계획에 따라 해당 지역의 재난 위험을 평가하도록 지정된 정부 기관인 국민안전처는 새로운 손실 산정 방법을 개발하고 있다. 본 연구의 목적은 범용 최소자승 회귀분석법과 지리적 가중 회귀분석법을 이용하여 주거용, 상업용, 농업용 건물 유형을 기반으로 군산시의 홍수 피해를 추정하는 홍수피해추정 손실함수를 개발하는 것이다. 모델은 홍수심, 홍수 지속시간, 범람 면적, 가족 수입, 토지 가격을 매개 변수로 구축 된다. 본 연구에서는 홍수피해추정을 위해 범용 최소자승 회귀분석법과 지리적 가중 회귀분석법을 평가하였으며 지리적 가중 회귀 분석법이 홍수피해 추정에는 더 적합한 것으로 분석 되었다. Despite the growing economy and improving disaster prevention techniques of Korea, natural disasters such as floods, typhoon, drought have still threatened people. The counteractions made by flood disasters that were also induced by typhoons have caused significant damages to properties and human life. Estimating flood damage is essential make countermeasures in order to mitigate flood disaster. In this regard, the Ministry of Safety and Security (MPSS), the government institution designated to assess and analyze the damages and losses as well as evaluate the disaster risks of the said areas in accordance to their disaster risk management plans, are now developing a new estimating method for damages and losses. This study aims to develop flood damage functions that will estimate the flood damages of Gunsan City based on the building type: residential, commercial and agricultural facilities, by utilizing the Ordinary Least Squares Regression (OLS) and later on, the Geographically Weighted Regression (GWR). The model building process includes flood depth, flood duration, inundated area, family income and land price as the parameter variables. Both OLS and GWR were evaluated in this study, but the search for which among them is the best fit resulted to the use of GWR.