DOCSLIB.ORG

Runoff Analysis Using Satellite Data for Regional Flood

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Runoff Analysis Using Satellite Data for Regional Flood Kochi University of Technology Academic Resource Repository � Runoff Analysis using Satellite Data for Regiona Title l Flood Assessment - Spatial and Time Series Bia s Correction of Satellite Data - Author(s) PAKOKSUNG, Kwanchai Citation 高知工科大学, 博士論文. Date of issue 2016-09 URL http://hdl.handle.net/10173/1422 Rights Text version ETD � � Kochi, JAPAN http://kutarr.lib.kochi-tech.ac.jp/dspace/ Runoff Analysis using Satellite Data for Flood Reginal Assessment: Spatial and Time-series Bias Correction of Satellite Data Kwanchai Pakoksung A dissertation submitted to Kochi University of Technology in partial fulfillment of the requirements for the degree of Doctor of Engineering Graduate School of Engineering Kochi University of Technology Kochi, Japan September 2016 i ii Abstract Floods are one of all the major natural disasters, affecting to human lives and economic loss. Understanding floods behavior using simulation modelling, of magnitude and flow direction, is the challenges of hydrological community faces. Most of the floods behaviors are depended on mechanism of rainfall and surface data sets (topography and land cover) that are specific for some area on a ground observation data. Remote sensing datasets possess the potential for flood prediction systems on a spatially on datasets. However, the datasets are confined to the limitation of space-time resolution and accuracy, and the best apply of these data over hydrological model can be revealed on the uncertainties for the best flood modelling. Furthermore, it is important to recommend effective of data collecting to simulate flood phenomena. For modelling nearby the real situation of the floods mechanism with different data sources, the difficult task can be solved by using distributed hydrological models to simulate spatial flow based on grid systems. Therefore, the objective of this dissertation is to contribute the correction and evaluation of remote sensing sources for flood prediction through basin scales, and application of the model to demonstrate the approach of flood risk estimation method on small area. It also aims to present and create general bias methodology for runoff analysis using the remote sensing data sources to model the flood simulation. The geographical point of this study is the Yoshino river basin in Japan and the Upper part of Nan river basin in Thailand. Firstly, the modification and implementation of distributed hydrological modeling as the RRI model are included by VOXEL model for convenient on input and output and the GPU coding for speedup. The VOXEL model was used to integrate the input data the watershed data (DEM and Land cover) and rainfall data (spatial and temporal) and the output data runoff and inundation depth (spatial and temporal). The GPU on NVIDIA CUDA was setup for speedup about 2.6x on the complex terrain. The accuracy assessment, bias correction method evaluation, and impact of flood analysis validation were shown in the second part based on three components of flood mechanism, DEM, satellite land cover, and satellite based rainfall. The six DEM sources (GSI-DEM, ASTER GDEM, SRTM, GMTED2010, HydroSHEDS, and GTOPO30) evaluated by the referent elevation points (GCP) that are used to estimate bias correct coefficient based on spatial linear transformation, and then the data are driven by the distributed hydrologic model (RRI) to reveal the impact of the topography sources. The GSI-DEM was a high accuracy among the five DEMs and the correction algorithm could improve the accuracy responding with the coarse resolution DEMs (HydroSHEDS and GTOPO30), while the high resolution (GSI-DEM, ASTER GDEM, SRTM, and GMTED2010) had a small sensitivity. In the Shikoku Island, ASTER DEM was suitable for runoff simulation, have estimated from stereo matching. SRTM presented a performance for runoff and inundation simulation in the Nan river basin, have explored from radar laser scan with Shuttle. MODIS product outperformed iii AVHRR products that Manning’s coefficient of MODIS also showed higher performance. The MODIS roughness also presented higher performance evaluated from the hydrological modeling results. The rain gauges were interpolated into grid system with five algorithms, Inverse Distance Weight (IDW), Thiessen Polygon (TSP), Simple Kriging (SKG), Ordinary Kriging (OKG), and Surface Polynomial (SPL). The IDW outperformed as high performance algorithm in the Shikoku area that represented with the dense rain gauge network area, while the sparse rain gauge network area was the Nan river basin that the SKG was suitable algorithm. GSMaP and GPV showed the high accuracy for the Shikoku in Japan, while CMORPH outperformed among other sources in the Nan area in Thailand, on the international sources. GPV and GSMaP in Japan and GPM in Thailand as the high resolution showed the highest performance on runoff simulation, while low resolution was TRMM. The five algorithms (Mean ratio, Geometrics transformation, Linear transformation, Data assimilation, and Quantile mapping) and two schemes (Temporal and Spatial) were evaluated only GPM and TRMM in the Nan river basin, Thailand. The three algorithms (Linear, Geometrics, Data assimilation) on the spatial scheme showed the high performance, resulting from runoff validation. Finally, the application of the remote sensing data sets on flood forecasting and flood risk assessment was demonstrated. The first approach, the river basin scale simulation was used to define as the boundary condition of small area to simulate a high resolution of flood map. The second approach based on small area results, the flood risk assessment was consisted by hazard and vulnerability data. In this task, the streamflow for estimating the flood risk map was the main point for proposing. iv Acknowledgments The author would like to express my sincerely thanks to advisor professor Masataka TAKAGI for his overall supports to form this research fulfillment. With his strong supports, advising and guidance; this research is successfully done. Continuously, I would like to add my gratitude to supervisory committee members: Prof. Seigo NASU, Prof. Yoshiro KAI, Associate Prof. Takashi GOSO, and Associate Prof. Masayuki MATSUOKA for their valuable suggestions and comments to improve my research works. The author wishes to acknowledge Prof. Lawrie Hunter for English research writing. A great supports for my study is the Special Scholarship Program (SSP) of Kochi University of Technology for doctoral scholarship program in Japan. The author would like to thank all staffs of International Relationship Center for guidance on living, and many other helps. Furthermore, Takagi laboratory member are to helps and share their times and knowledge in my endurance on the research. The author would like to thank Dr. Nattakorn Bongochgetsakut for his expert suggestion in developing the GPU model, and Dr. Pongsak Suttinon for his expert suggestion in understanding the economic model. Finally, the author would like to thank my parents, and my wife and my sons, with a beautiful life. v vi Table of Content Pages Title page i Abstract iii Acknowledgments v Table of contents vii List of figures xi List of tables xvii 1. Introduction 1 1.1 Motivation 1 1.2 Overview of the thesis 7 1.2.1 Research problem and objectives 7 1.2.2 Scope of the dissertation 8 1.3 Outline of the dissertation 9 1.4 Study area 12 1.4.1 Shikoku Island, Japan 12 1.4.2 Nan river basin, Thailand 14 2. Hydrological modeling 15 2.1 Introduction 15 2.2 Hydrological model by the RRI model 18 2.2.1 Concept of RRI model 18 2.2.2 Components of the RRI model programming 19 2.3 VOXEL model assisted RRI model 21 2.3.1 VOXEL model 21 2.3.2 Application for the RRI model 22 2.4 Model setup 23 2.4.1 Setup parameter 24 2.4.2 Performance statistical 25 2.4.3 GPU on the RRI model 27 2.5 Modeled results 30 2.5.1 VOXEL model of watershed and rainfall data for the RRI model 30 2.5.2 Simulated runoff and inundation map 31 2.5.3 Speedup of the GPU-RRI model 34 2.6 Conclusion 39 vii Table of Content (continued) Pages 3. Bias correction of DEM sources and their effect on estimation of runoff and 41 inundation area 3.1 Introduction 41 3.2 Data and Methodology 43 3.2.1 Digital Elevation Model sources and Reference elevation points 43 3.2.2 Accuracy assessment 48 3.2.3 Bias correction 52 3.2.4 Hydrological simulation 53 3.3 Results and Discussion 54 3.3.1 Geomorphological property of DEMs 54 3.3.2 Accuracy assessment of DEMs 57 3.3.3 Effect of terrain morphology in the DEMs accuracy 65 3.3.4 Effect of land cover in the DEM accuracy 69 3.3.5 Evaluation of the river network 71 3.3.6 DEMs bias correction 73 3.3.7 Effect of DEM sources on runoff simulation: Shikoku Island, Japan 78 3.3.8 Effect of DEM sources on runoff simulation: Nan river basin, Thailand 81 3.3.9 Effect of DEM sources on flood area simulation: Nan river basin, Thailand 84 3.4 Conclusion 85 4. Estimation of surface roughness based on land cover datasets and their effect on 88 Distributed Rainfall-Runoff simulation 4.1 Introduction 88 4.2 Data and Methodology 90 4.2.1 Land cover based satellite and Land cover referent map 90 4.2.2 Manning’s n coefficient estimation 94 4.2.3 Hydrological simulation 95 4.2.4 Accuracy assessment 96 4.3 Results and Discussion 97 4.3.1 Accuracy assessment of Land cover based satellite data: MODIS product 97 4.3.2 Accuracy assessment of Land cover based satellite data: AVHRR product 103 4.3.3 Manning’s n coefficient based satellite sources evaluation: Shikoku Island, 108 Japan 4.3.4 Manning’s n coefficient based satellite sources evaluation: Nan river basin, 113 Thailand viii Table of Content (continued) Pages 4.3.5 Effect of Land Cover-based Surface roughness on Hydrological model 117 Results: Shikoku Island, Japan 4.3.6 Effect of Land Cover-based Surface roughness on Hydrological model 119 Results: Nan river basin, Thailand 4.4 Conclusion 122 5.
Load more

Recommended publications
  • RCP8.5-Based Future Flood Hazard Analysis for the Lower Mekong River Basin
    hydrology Article RCP8.5-Based Future Flood Hazard Analysis for the Lower Mekong River Basin Edangodage Duminda Pradeep Perera 1,*, Takahiro Sayama 2, Jun Magome 3, Akira Hasegawa 4 ID and Yoichi Iwami 5 1 United Nations University–Institute for Water, Environment and Health, Hamilton, ON L8P 0A1, Canada 2 Disaster Prevention Research Institute, Kyoto University, Kyoto 611-0011, Japan; [email protected] 3 International Research Centre for River Basin Environment, University of Yamanashi, Kofu 400-8511, Japan; [email protected] 4 International Centre for Water Hazard and Risk Management, Public Works Research Institute, Tsukuba, Ibaraki 302-8516, Japan; [email protected] 5 Nagasaki Prefectural Civil Engineering Department, Nagasaki 850-8570, Japan; [email protected] * Correspondence: [email protected]; Tel.: +1-905-667-5483 Received: 13 September 2017; Accepted: 21 November 2017; Published: 23 November 2017 Abstract: Climatic variations caused by the excessive emission of greenhouse gases are likely to change the patterns of precipitation, runoff processes, and water storage of river basins. Various studies have been conducted based on precipitation outputs of the global scale climatic models under different emission scenarios. However, there is a limitation in regional- and local-scale hydrological analysis on extreme floods with the combined application of high-resolution atmospheric general circulation models’ (AGCM) outputs and physically-based hydrological models (PBHM). This study has taken an effort to overcome that limitation in hydrological analysis. The present and future precipitation, river runoff, and inundation distributions for the Lower Mekong Basin (LMB) were analyzed to understand hydrological changes in the LMB under the RCP8.5 scenario.
    [Show full text]
  • The Geneva Reports
    The Geneva Reports Risk and Insurance Research www.genevaassociation.org Extreme events and insurance: 2011 annus horribilis edited by Christophe Courbage and Walter R. Stahel No. 5 Marc h 2012 The Geneva Association (The International Association for the Study of Insurance Economics The Geneva Association is the leading international insurance think tank for strategically important insurance and risk management issues. The Geneva Association identifies fundamental trends and strategic issues where insurance plays a substantial role or which influence the insurance sector. Through the development of research programmes, regular publications and the organisation of international meetings, The Geneva Association serves as a catalyst for progress in the understanding of risk and insurance matters and acts as an information creator and disseminator. It is the leading voice of the largest insurance groups worldwide in the dialogue with international institutions. In parallel, it advances—in economic and cultural terms—the development and application of risk management and the understanding of uncertainty in the modern economy. The Geneva Association membership comprises a statutory maximum of 90 Chief Executive Officers (CEOs) from the world’s top insurance and reinsurance companies. It organises international expert networks and manages discussion platforms for senior insurance executives and specialists as well as policy-makers, regulators and multilateral organisations. The Geneva Association’s annual General Assembly is the most prestigious gathering of leading insurance CEOs worldwide. Established in 1973, The Geneva Association, officially the “International Association for the Study of Insurance Economics”, is based in Geneva, Switzerland and is a non-profit organisation funded by its members. Chairman: Dr Nikolaus von Bomhard, Chairman of the Board of Management, Munich Re, Munich.
    [Show full text]
  • Trace Elements in Marine Sediment and Organisms in the Gulf of Thailand
    International Journal of Environmental Research and Public Health Review Trace Elements in Marine Sediment and Organisms in the Gulf of Thailand Suwalee Worakhunpiset Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchavithi Rd, Bangkok 10400, Thailand; [email protected]; Tel.: +66-2-354-9100 Received: 13 March 2018; Accepted: 13 April 2018; Published: 20 April 2018 Abstract: This review summarizes the findings from studies of trace element levels in marine sediment and organisms in the Gulf of Thailand. Spatial and temporal variations in trace element concentrations were observed. Although trace element contamination levels were low, the increased urbanization and agricultural and industrial activities may adversely affect ecosystems and human health. The periodic monitoring of marine environments is recommended in order to minimize human health risks from the consumption of contaminated marine organisms. Keywords: trace element; environment; pollution; sediment; gulf of Thailand 1. Introduction Environmental pollution is an urgent concern worldwide [1]. Pollutant contamination can exert adverse effects on ecosystems and human health [2]. Trace elements are one type of pollutant released into the environment, and metal contamination levels are rising. The main sources of trace elements are natural activities such as volcanic eruptions and soil erosion, and human activities such as industrial production, waste disposal, the discharge of contaminated wastewater, the inappropriate management of electronic waste (e-waste), and the application of fertilizers in agriculture [3–7]. Once trace elements are released into the environment, they can be dispersed by the wind and deposited in soil and bodies of water, accumulating in marine sediments [8,9].
    [Show full text]
  • II. the Worst Floods in Thailand in Half a Century
    II. The Worst Floods in Thailand in Half a Century: The 2011 Floods September 2016 1 Preface Whilst Asia is ranked as the most disaster prone region in the world in terms of both natural and man- made disasters, research and training in the Asia-Pacific region is limited. Better understanding of the disaster epidemiological profile and human health impact will enhance response, preparedness and mitigation of the adverse human impact of disaster. The concept of case-teaching method has been used extensively in research and teaching of disasters and humanitarian studies at schools of public health around the world, including Harvard School of Public Health, Johns Hopkins Bloomberg School of Public Health and London School of Hygiene and Tropical Medicine. Through the existing partners and networks of The Jockey Club School of Public Health and Primary Care, the Public Health Humanitarian Initiatives of The Chinese University of Hong Kong, and the Collaborating Centre for Oxford University and CUHK for Disaster and Medical Humanitarian Response, this disaster and humanitarian relief monograph series composed of 8 case study reports have been developed using a standardized analytical and reporting framework. Methods for case study including literature review, stakeholder interviews and retrospective data analysis have been employed. This case study series aims at highlighting the key lessons learnt in disaster medical and public health response in the Asia. The goal is to develop Asia-specific teaching materials for public health and medicine in disaster and humanitarian response. The “Guidelines for Reports on Health Crises and Critical Health Events” framework has been adopted as a reference for the literature search and the identification of key areas for analysis (1).
    [Show full text]
  • Trace Elements in Marine Sediment and Organisms in the Gulf of Thailand
    International Journal of Environmental Research and Public Health Review Trace Elements in Marine Sediment and Organisms in the Gulf of Thailand Suwalee Worakhunpiset Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchavithi Rd, Bangkok 10400, Thailand; [email protected]; Tel.: +66-2-354-9100 Received: 13 March 2018; Accepted: 13 April 2018; Published: 20 April 2018 Abstract: This review summarizes the findings from studies of trace element levels in marine sediment and organisms in the Gulf of Thailand. Spatial and temporal variations in trace element concentrations were observed. Although trace element contamination levels were low, the increased urbanization and agricultural and industrial activities may adversely affect ecosystems and human health. The periodic monitoring of marine environments is recommended in order to minimize human health risks from the consumption of contaminated marine organisms. Keywords: trace element; environment; pollution; sediment; gulf of Thailand 1. Introduction Environmental pollution is an urgent concern worldwide [1]. Pollutant contamination can exert adverse effects on ecosystems and human health [2]. Trace elements are one type of pollutant released into the environment, and metal contamination levels are rising. The main sources of trace elements are natural activities such as volcanic eruptions and soil erosion, and human activities such as industrial production, waste disposal, the discharge of contaminated wastewater, the inappropriate management of electronic waste (e-waste), and the application of fertilizers in agriculture [3–7]. Once trace elements are released into the environment, they can be dispersed by the wind and deposited in soil and bodies of water, accumulating in marine sediments [8,9].
    [Show full text]
  • Conflicts and Politics Associated with the 2011 Thailand Flood
    Conflicts and Politics Associated with the 2011 Thailand Flood Yoshifumi TAMADA INTRODUCTION Floods involve not only technical issues such as identifying the causes, developing and implementing disaster control measures, and water resource management; they also involve issues of profit and loss distribution, with decisions related to when and how sacrifices, compensation, and relief are assigned to whom (Kasian 2011). The 2011 Thailand floods involved not only a people’s fight against water, but also involved many cases of conflict among people. Amid the floods, people sought scapegoats for the causes of the floods, claiming that the disaster was beyond imagination to evade blame. They argued about which communities should face the force of the river overflow. Fierce conflicts related to guidance of the flood flows to one community or another erupted particularly between Bangkok and neighboring provinces, and within Bangkok, between the left and right banks of the Chao Phraya River and on the left bank between the Phra Nakhon Area and the eastern area. Heated arguments arose in relation to short-, medium-, and long-term flood control measures, involving issues such as whether to build a dam in an upstream area or not, where in a midstream area to place a retarding 1 basin, whether to build a ring levee around entire industrial estates and urban areas to prevent water inflow in the downstream delta area or not, and who is responsible for undertaking their design and construction. Regarding the issue of aid for flood victims, community neighbors disputed who should receive ex gratia and compensatory payments. Disputes associated with the floods in various aspects intensified while involving political conflicts.
    [Show full text]
  • Impact of the 2011 Floods, and Flood Management in Thailand NIPON POAPONSAKORN Thailand Development Research Institute
    ERIA-DP-2013-34 ERIA Discussion Paper Series Impact of the 2011 Floods, and Flood Management in Thailand NIPON POAPONSAKORN Thailand Development Research Institute PITSOM MEETHOM Thailand Development Research Institute November 2013 Abstract: This paper first describes the causes of the major flooding in Thailand in 2011, which include natural events, unregulated land-use patterns and flood mismanagement. It discusses the government’s quick response in drafting a flood management master plan and allocating USD 11,290 million for assistance and compensation for flood victims, restoration of damaged property, and implementation of the master plan. The weakness of the master plan is also pointed out. The study goes on to develop the “difference-in-difference” method to estimate the impact of the flooding on household income and expenditure in 26 flooded provinces. It matches the addresses of flooded households taken from the 2011 Socio-economic Survey, which did not have questions regarding the impact of floods, with the flooded areas from satellite radar images. Quantile regressions are employed to quantify the differential impact of the flood on households with different income levels. The results show that the flooding reduced total household expenditures by 5.7% to 14%. These findings are consistent with the reported negative national GDP growth of 8.9 % in the fourth quarter of 2011 when Thailand was flooded. One interesting finding is that the 2011 floods had a significantly negative impact on the income and expenditure of middle and high income households, but that its impact on poor households was not statistically significant. The study also finds that the 2011 floods had a negative impact on the money and wage incomes of some middle income households living in the flooded areas.
    [Show full text]
  • Housing and Informal Settlements
    11 Housing and Informal Settlements Coordinating Lead Authors Nathalie Jean-Baptiste (Leipzig/Dar es Salaam), Veronica Olivotto (Rotterdam) Lead Authors Emma Porio (Manila), Wilbard Kombe (Dar es Salaam), Antonia Yulo-Loyzaga (Manila) Contributing Authors Ebru Gencer (New York/Istanbul), Mattia Leone (Naples), Oswaldo Lucon (São Paulo), Mussa Natty (Dar es Salaam) This chapter should be cited as Jean-Baptiste, N., Olivotto, V., Porio, E., Kombe, W., and Yulo-Loyzaga, A. (2018). Housing and informal settlements. In Rosenzweig, C., W. Solecki, P. Romero-Lankao, S. Mehrotra, S. Dhakal, and S. Ali Ibrahim (eds.), Climate Change and Cities: Second Assessment Report of the Urban Climate Change Research Network. Cambridge University Press. New York. 399–440 399 Downloaded from https://www.cambridge.org/core. University of Sussex Library, on 16 Apr 2018 at 16:56:42, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/9781316563878.018 ARC3.2 Climate Change and Cities Housing and Informal Settlements • Access to safe and secure land is a key measure for reduc- ing risk in cities. Groups that are already disadvantaged with Addressing vulnerability and exposure in the urban hous- regard to housing and land tenure are especially vulnerable ing sector is critical in informal settlements where extreme to climate change. climate events present multiple risks for millions of people. Understanding the impacts of mitigation and adaptation strat- • In informal settlements, successful adaptation depends upon egies on the housing sector will help decision-makers make addressing needs for climate related expertise and resources choices that improve quality of life and close development and at different government levels as well as risk-reducing phys- equity gaps in cities.
    [Show full text]
  • Feature Articles on Thailand Lamphun
    FETL Lamphun Plant Fujikura Automotive (Thailand) Ltd. Feature FETL Ayutthaya Plant Feature Articles on Thailand Lamphun Korat This year marks the 32nd anniversary since Fujikura started Saraburi Ayutthaya operations in Thailand in 1984. Thailand FETL Kabinburi Plant Kabinburi Navanakorn In April 2010, Fujikura Electronics Thailand Ltd. (hereafter FETL) Prachinburi Bangkok was founded through the consolidation of separately run companies. FETL Navanakorn Plant 1 FETL Prachinburi Plant The Fujikura Group in Thailand has grown to include Fujikura FETL Navanakorn Plant 2 Bangkok Office, seven plants of FETL, DDK (Thailand) Ltd. and FETL Navanakorn Plant 3 two plants of Fujikura Thailand Automotive (THAILAND) Ltd. We DDK（THAILAND） Ltd. are grateful to our customers and partners for their support, which enabled us to achieve this. In October 2011, because of the most disastrous flooding in Thailand, 10 of our 13 bases there at that time were submerged in water within as short as two weeks to cause devastating damage. Managing Executive Officer Fujikura Electronics (Thailand) Ltd. In such a critical situation, the entire group companies worked FETL Bangkok Office President & CEO hard as one with then CEO Mr. Nagahama's strong determination Ikuo Kobayashi to reconstruct the facilities and resume the operations. In 2015, The office is in charge of Fujikura product sales to Thailand. With the production volume got back to its pre-flooding level thanks to customer satisfaction in mind, the being blessed with good customers. staff is engaged in sales activities to Our local staff of the plants will take the lead in improving 2016 meet a variety of customer needs.
    [Show full text]
  • The 2011 Thailand Floods in the Lower Chao Phraya River Basin in Bangkok Metropolis
    The 2011 Thailand Floods in The Lower Chao Phraya River Basin in Bangkok Metropolis The 2011 Thailand Floods in The Lower Chao Phraya River Basin in Bangkok Metropolis Author: Ms. Pitchapa Jular – Massachusetts Institute of Technology Editors: Mr. Kenge James Gunya – Knowledge Management Officer; GWP Global Secretariat Mr. Francois Brikke – Senior Network Officer and focal point for Urban Water; GWP Global Secretariat Mr. Simo Lu – Network Operations Intern – GWP Global Secretariat The views expressed in this case study do not necessarily represent the official views of GWP. Novemeber 2017 www.gwp.org/ToolBox About Global Water Partnership The Global Water Partnership’s vision is for a water secure world. Our mission is to advance governance and management of water resources for sustainable and equitable development. GWP is an international network that was created in 1996 to foster the implementation of integrated water resources management: the coordinated development and management of water, land, and related resources in order to maximise economic and social welfare without compromising the sustainability of ecosystems and the environment. The GWP Network is open to all organisations which recognise the principles of integrated water resources management endorsed by the Network. It includes states, government institutions (national, regional, and local), intergovernmental organisations, international and national non-governmental organisations, academic and research institutions, private sector companies, and service providers in
    [Show full text]
  • Flood Frequency Analysis Under Climate Change Effects in the Lower Mekong Basin Using D4pdf Datasets
    C11 Flood Frequency Analysis under Climate Change Effects in the Lower Mekong Basin using d4PDF Datasets 〇Sophal TRY, Shigenobu TANAKA, Kenji TANAKA, Takahiro SAYAMA, Chantha OEURNG Introduction Method The future change of intensity and frequency of The Rainfall-Runoff-Inundation (RRI) model, a precipitation will definitely affect the flood distributed rainfall-runoff and inundation model with characteristic in the river basin. The insufficient diffusive wave approximation (Sayama et al., 2014), number of ensemble members would lead to increase was used for flood inundation simulation in this study. uncertainty in climate simulation. To deal with this The RRI model was calibrated and validated for the issue, the objective of this study is to evaluate future MRB from the previous study (Try et al., 2020). The changes of flood extreme in the Mekong River Basin Generalized Extreme Value (GEV) was used for flood (MRB) using a large ensemble dataset. extreme fitting (annual peak discharge). The Study Area Kolmogorov-Smirnov (K–S) test of two samples was The MRB is one among the world global also used to distinguish the likelihood from each SST large-scale basins where flood occurs almost every pattern. Combination cases of two samples from 6 year. More than 60 million people live in the Lower SST patterns (15 combination cases) were tested. The Mekong Basin (LMB) in Thailand, Lao PDR, null hypothesis assumes that two samples have no Cambodia, and Vietnam where the annual average significant difference of their cumulative distribution flood economic damage ranges US$ 60-70 million. function. The frequency and severity of extreme flood in this This study used the database for policy region were expected to be significantly affected by decision-making for future climate change (d4PDF) climate change effects.
    [Show full text]
  • Long-Term Trends and Variability of Total and Extreme Precipitation in Thailand
    Atmospheric Research 169 (2016) 301–317 Contents lists available at ScienceDirect Atmospheric Research journal homepage: www.elsevier.com/locate/atmos Long-term trends and variability of total and extreme precipitation in Thailand Atsamon Limsakul a,⁎,PatamaSinghruckb a Environmental Research and Training Center, Technopolis, Klong 5, Klong Luang, Pathumthani 12120, Thailand b Department of Marine Science, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok 10330, Thailand article info abstract Article history: Based on quality-controlled daily station data, long-term trends and variability of total and extreme precipitation Received 20 September 2014 indices during 1955–2014 were examined for Thailand. An analysis showed that while precipitation events have Received in revised form 30 September 2015 been less frequent across most of Thailand, they have become more intense. Moreover, the indices measuring the Accepted 19 October 2015 magnitude of intense precipitation events indicate a trend toward wetter conditions, with heavy precipitation Available online 27 October 2015 contributing a greater fraction to annual totals. One consequence of this change is the increased frequency and fl fl Keywords: severity of ash oods as recently evidenced in many parts of Thailand. On interannual-to-interdecadal time fi Thailand scales, signi cant relationships between variability of precipitation indices and the indices for the state of El Trend Niño–Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) were found. These results provide addi- Precipitation tional evidence that large-scale climate phenomena in the Pacific Ocean are remote drivers of variability in Extreme indices Thailand's total and extreme precipitation. Thailand tended to have greater amounts of precipitation and more extreme events during La Niña years and the PDO cool phase, and vice versa during El Niño years and the PDO warm phase.
    [Show full text]