ArcGIS® toolbox USER MANUAL - Sydney Coastal Councils Group
Contents
1. gt ie cum c A METHOD FOR ASSESSING THE VULNERABILITY OF BUILDINGS TO CATASTROPHIC TSUNAMI MARINE FLOODING ArcGISO toolbox USER MANUAL FILIPPO DALL OSSO and DALE DOMINEY HOWES This ArcGIS toolbox User Manual was developed as part of a collaborative research project called method for assessing the vulnerability of buildings to catastrophic marine tsunami flooding The project partners include Sydney Coastal Councils Group SCCG Geoff Withycombe Regional Coastal Environment Officer Executive Officer Level 12 456 Kent Street GPO Box 1591 Sydney NSW 2001 DX 1251 Sydney Ph 61 2 9246 7791 Fax 61 2 9265 9660 Web Site www sydneycoastalcouncils com au Email geoff sydneycoastalcouncils com au UNSW RQA THE UNIVERSITY OF NEW SOUTH WALES The University of New South Wales UNSW Dale Dominey Howes Associate Professor Australian Tsunami Research Centre School of Biological Earth and Environmental Sciences Faculty of Science UNSW Sydney NSW 2052 Tel 61 2 9385 4830 Fax 61 2 9385 1558 Mobile 61 0 401 647 959 Email dale dh unsw edu au MED INGEGNERIA 6 eet ALMA MATER STUDIORUM The University of Bologna Interdepartmental Centre for Environmental Sciences Research CIRSA Faculty of Environmental Sciences 48100 Ravenna Italy MEDINGEGNERIA S r l Hydraulic and Coastal Engineering2. 1 The Inundation Depth field name water depth is the depth of the water in metres expected to surround inundate the building according to the inundation scenario The inundation depth is obtained by selecting buildings by location by making an intersection with the water depth polygon shapefile To do this in the water depth shapefile select 13 the polygon corresponding to 1 metre of inundation Then in the ArcMap toolbar click Selection Select by location In the selection window that appears choose the select features from option tick the inundated buildings layer select intersect in the following box tick the water depth layer in the last box and tick the Use selected features option Figure 1 All the buildings touched by only 1 metre of water will be selected It is now possible to put 1 in their attribute table under the field water depth Now repeat the selection by location intersecting inundated buildings with the polygon corresponding to 2 metres of inundation you need this polygon to be selected before the selection by location runs Write 2 in the water depth field of the selected buildings and repeat the entire process for all the other values of inundation depth Pde a RS Lets you select features from or more layers based where they are located in relation to the features in a
3. Italy 16 Via Pietro Zangheri 48100 Ravenna Italy Web Site www medingegneria it Email info medingegneria it Dall Osso Filippo PhD student Medingegneria consultant Mobile 4 39 329 2215925 Office 39 0544 467359 Fax 39 0544 501984 Email filippodallosso gmail com UNSW and the Sydney Coastal Councils Group Inc to the extent permitted by law all rights are reserved and no part of this Manual covered by copyright may be reproduced or copied in any form or any means without the written permission of the original authors However this Manual may be utilised for the purposes of undertaking tsunami vulnerability assessment research as detailed in the accompanying report Dall Osso and Dominey Howes must be acknowledged as the original authors of the method detailed herein CONTRIBUTING AUTHORS Filippo Dall Osso The University of Bologna Italy filippodallosso gmail com Dale Dominey Howes The University of New South Wales Australia dale dh unsw edu au Cover image Filippo Dall Osso All rights reserved Contents Ts INTRODUCTION nrc ved sisuscsesetslsossacsoosenaascsetedssoseasedsssetsices 5 1 1 PROJECT BACKGROUND AND AIMSG cesceesseeseesseeseeeseeesecesecesecsneccecseceseceaeceaecnaecsaesseeeseeeseseaecesesenesseeeseseaeeeatonas 5 1 2 THE USERS MANUAL e eg A 6 1 3 THE METHOD THEORETICAL BACKGROUND sinccr eaei a iiie eai 1 1 4 THE INUNDATION SCENA
4. 6 References Dalrymple R A Kriebe D L Lessons in Engineering from the Tsunami in Thailand The Bridge 35 4 13 2005 Dominey Howes D and Papathoma M Validating a Tsunami Vulnerability Assessment Model the PTVA Model Using Field Data from the 2004 Indian Ocean Tsunami Natural Hazards 40 113 136 2007 Matsutomi H Sakakiyama T Nugroho S Matsuyama M Aspects of inundated flow due to the 2004 Indian Ocean tsunami Coastal Engineering Journal 48 2 167 195 2006 Mitchell J T and Cutter S L Global Change and Environmental Hazards Is the World Becoming More Disastrous Association of American Geographers Washington DC 1997 Olwig M F Sorensen M K Rasmussen M S Danielsen F Selvams V Hansen L B Nyborg L Vestergaard K B Parish F Karunaganas V M Using the remote sensing to assess the protective role of coastal woody vegetation against tsunami waves International Journal of Remote Sensing 28 13 14 3153 3169 2007 43 Reese S Cousins W J Power W L Palmer N G Tejakusuma 1 Nugrahadi S Tsunami vulnerability of buildings and people in South Java field observations after the July 2006 Java tsunami Natural Hazards and Earth System Sciences 7 573 589 2007 Terzaghi K Theoretical Soil Mechanics John Wiley and Sons New York 1943 Warnitchai P Lessons Learned from the 26 December 2004 Tsunami Disaster in Thailand in Proceedings of the 4th
5. International Symposium on New Technologies for Urban Safety of Mega Cities in Asia Singapore 18 19 October 2005 44
6. of stories Ground floor hydrodynamics field name g scores must be given to this field according to Table 1 Foundations Type field name f deep foundations are more resistant to the scouring effect of water flow and they can lessen the impact of the wave on building walls Scores must be given to this field according to Table 1 In the event that no data about foundation type are available the foundation strength can be inferred as a direct function of the load of the building and the type of soil Terzaghi 1943 If we assume that all the building structures we examined are engineered structures and that the type of soil is constant 16 the foundation strength becomes a direct function of the building load and load is correlated with the number of stories In this case the score for the foundations field will be the same as the score for the number of stories field s In order to obtain the best available estimate for the foundation factor we can consider this approximation to be acceptable Shape and orientation of the building footprint field name so during past tsunamis buildings with hydrodynamic shapes hexagonal triangular rounded etc suffered lighter damage than long rectangular or L shaped buildings with their main wall perpendicular to the water flow direction Warnitchai 2005 Dominey Howes and Papathoma 2007 Assuming the inundation will proceed in a direction p
7. vulnerability level Then click OK Modifying the properties of the inundated buildings shapefile allows to display them with a different colours according to their RVI score Buildings will be displayed with different colours reflecting their RVI value Finally a legend a scale bar a North arrow and some text boxes can be added to the map from the Layout view mode An map example for Manly is shown in Figure 10 40 General Source Selection Display Symbology Fields Definition Query Labels Joins amp Relates Show Features Draw categories using unique values of one field Import Field Color Ramp Unique values many symbolina Symbol Value laa LI all other values all other values Heading RVI 0 No data AVERAGE AVERAGE Charts Multiple Attributes HIGH HIGH Low Low VERY HIGH VERY HIGH VERY Low VERY LOW Add AllValues Add Values Remove Remove All Advanced ERE Figure 9 Modifying the properties of the inundated buildings shapefile allows to display them with a different colours according to their RVI score 41 MANLY BLOCK3 Pree Cavan denen ODA 1454 NDA Zone GE coin Scale 1 5 000 xm S Legend Flood Buildings Relative Vulnerability Index 0 1 EN Figure 10 Example of relative vulnerability map for the central area of Manly Sydney Australia 42
8. wan basem use munts notes 69 00 4 c e amp 53 ro OG 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Figure 3 Example of a table that should be completed during a field survey FID numbers would relate to individual buildings shown on the accompanying field block map e g Figure 2 26 4 INSTALLING AND RUNNING THE MODEL Once the inundated buildings shapefile is ready with all the required codes in the attribute table the model can be run If inputs have been inserted in accordance with guidelines the model will generate as outputs the Relative Vulnerability Index RVI scores for every building within a specific field named RVI 1 5 in the inundated buildings attribute table That value will represent the overall vulnerability level of the building The model will also calculate the structural vulnerability field named SV 1 5 and the vulnerability to prolonged contact with water field name WV 1 5 27 4 1 Installation The model has been created using the Model Builder function of ArcGIS 9 2 so once it is installed it can be used as any other GIS tool Before installing it copy the folder named tool from the CD Rom and paste it into your hard disk After that you will be ready to install the model Open the ArcToolbox by clicking on the correspondin
9. RIO 5 4 onde epe og t erepti Hep ROS REP 9 2 DATA NEEDED TD C 10 2 1 ORTHORECTIFIED IMAGES 7 55 52 ettet hn pet eet ec eee as de perte He albe eet 10 2 2 THE DIGITAL ELEVATION MODEL DEM esses eene enne nennen ient nennen eene nnne sena 11 2 3 THE INUNDATED BUILDINGS SHAPEFILE ceeeeeeeeeeeteeeneeeen em renenet ette ESTEER ESSEN enne et retnn E Ea SEER ESEESE 12 X EB QU EOL BRI BETA DACH 24 4 INSTALLING AND RUNNING THE MODEL eere eene eene teneas tns tense tn senses sens stas t tastes sees s tss 27 4 1 INSTALLATION iun ENT Eo a eet ea v s 28 4 2 RUNNING THE MODED annn 6 p HE HR E ne P en D ei NM HIR d eet icol 32 4 3 OUTPUTS cor aiu 34 5 DISPLAYING RESULTS THE VULNERABILITY 40 6 CREFERENCES 43 1 INTRODUCTION The Sydney Coastal Councils Group SCCG partnered with the University of New South Wales to undertake a research project that applied and tested a newly developed and highly novel GIS tool to assess the vulnerability of coastal infrastructure to catastrophic marine floods The outputs may be used by council to make decisions about long term strategic planning and development and by emergency services to preplan for future hazard events 1 1 Project Background and Aims Low lying coastal buildings are vulne
10. ained by comparing the height of the brick wall with the expected depth of the inundation inund_levs is the number of levels stories plus basement that would be inundated in every building WV_percent is the percentage of levels that would be inundated in every building This field is an intermediate step in the calculation of WV_1_5 BV_m1_p1 this field is an intermediate step in the calculation of BV_1_5 SV 1 125 this field is an intermediate step in the calculation of SV 1 5 Prot 0 1 this field is an intermediate step in the calculation of Prot 1 5 pot in sto this field is an intermediate step in the calculation of WV 1 5 39 5 DISPLAYING RESULTS THE VULNERABILITY MAPS Creating relative vulnerability maps is a simple process once the scores for the field 1 5 have been calculated by the model and the corresponding tags have been assigned to the field RVI according to Table 3 Relative vulnerability maps can now be obtained by plotting on the aerial or satellite images the inundated building shapefile using different colors for buildings with different vulnerability levels Enter the properties of the inundated building shapefile and select the Simbology tab In the box on the left choose Categories Unique Values and in the Value Field box choose RVI Figure 9 Click then on the Add all values button and select a colour for each
11. ded by the building row PROT_br natural barriers nb the presence of a seawall PROT_sw and the presence of a brick wall around the building PROT_w For further information about the relative weight of these factors please refer to the final project report available from the SCCG EX is the exposure score It is generated by the model starting from the inundation depth field water dept according to Table 4 37 Table 4 Giving a score to the Exposure Ex according to water depth Water Depth zero to 1 m 1to2m 2to3m 3to4m inund stor this field shows the number of stories excluding the basement that would be inundated in every building A storey is considered to be fully inundated when its height above the ground level is less than the inundation depth at that point Please note that every storey is assumed to be 3 metres high e g the first floor will be considered inundated if the inundation depth at that point is larger than 3 metres the second floor if the inundation depth is greater than 6 metres and so on level numb is the number of levels including basement in every building It is obtained by adding together the total number of stories with the total number of basement levels this field automatically generated by the model contains the inverse of the percentage of protection provided by the brick wall around the building garden It is 38 obt
12. del 23 3 FIELD SURVEYS In order to run the model all data listed in Section 2 must be gathered for each building In many cases some data may be obtained from the local government authority but in most cases building attributes will need to be identified via field surveys If the number of buildings to be surveyed is large it is worthwhile dividing buildings into two or more blocks Blocks can also be created if buildings are located in two or more different areas far from each other Field surveys should be undertaken block by block For each block a map must be created using the GIS and printed out for use in the field survey The map must contain all the buildings on the block labeled with a unique Identification Number Figure 2 Together with the map the empty attribute table for the relevant buildings must be printed and brought into the field Figure 3 In the first column FID all the building Identification Numbers should be listed for that block so that the field surveyors will be able to find buildings on the map and record their attributes in the table 24 Once a table is completed all data must be manually transferred into the GIS according to the instructions described in Section 2 This phase is time consuming and great care should be taken to ensure no data transcription errors occur Figure 2 Example of a map used during field surveys 25 FID material ar oor stories
13. eed to be digitalized as polygons in order to generate an ESRI shapefile named inundated buildings In some cases this kind of file already exists and it may be obtained from local authorities However it will always need some modification and it will not contain the attribute data needed for every building In order to facilitate the work of this user s manual the inundated buildings shapefile has already been inserted in the associated CD Rom This file contains the attribute table needed to run the 12 vulnerability model The table is however empty because no buildings have been digitalized although it does contain the fields that will need to be filled with building features once their digitalization is complete Users will need to upload this file into the GIS ESRI ArcMap 9 2 and start editing with the Create new feature mode To understand what buildings need to be digitalized because they would be inundated users will need to display in the GIS both the aerial or satellite images and the water depth shapefile A good digitalization result can be achieved by working at a scale higher than 1 2000 Once all the building footprints have been digitalized and saved users will be ready to start completing the attribute table The list of the attributes needed for every building is shown below They are also reported as a field a column in the table of attributes of the inundated buildings shapefile
14. erpendicular to the shoreline scores must be given to this field according to Table 1 Preservation Conditions field name pc scores must be given to this field according to Table 1 Movable Objects field name mo during inundation movable objects will be dragged around by flowing water Buildings close to car parks or to crossroads are more likely to be damaged by this secondary flood effect Darlymple and Kriebel 2005 Scores for this field must be given according to Table 1 17 9 10 Building Row there are two fields for this attribute build row and PROT br one of the most important factors providing protection from the impact forces of a tsunami is the number of other structures located between a particular building and the coastline Post tsunami field surveys demonstrated that buildings located in rows further inland were somewhat shielded even when buildings in front of them collapsed Dominey Howes and Papathoma 2007 Reese et al 2007 Scores must be given to the field PROT br according to Table 2 In the field build row just write the number of the row where the building is located The row closest to the shoreline is row 1 Sometimes when rows are not evident and there are many adjacent buildings it can be useful to ask this question how many structures capable of shielding this building are present between it and the shore Seawall field name PROT sw vertical seawalls normall
15. g icon located in the Arcmap toolbar Then 1 Right click in the ArcToolbox window onto the white empty area under the tools list Figure 4 2 Select Add Toolbox from the menu that will appear Figure 4 3 Look for the tool folder on your hard disk and select the Inundation Vulnerability toolbox 4 Click on Open The model tool will be added to your toolbox 28 Senza titolo ArcMap ArcView File Edit View Insert Selection Tools Window Help Dei sex Ou 0 0 3D Analyst Layer 7 Spatial Analyst Y Layer ArcToolbev Figure 4 Installation of the model in to the ArcGis platform steps 1 and 2 29 p 3D Toolbox Anal Add Toolbox k Qe Com Environments Hp Date H Hide Locked Tools Settings gt Line Spat Load Settings spatia Name Inundation_vulnerabilty Show of type Toolboxes Cancel Figure 5 Installation of the model in to the ArcGis platform steps 3 and 4 30 Now the model is correctly installed on your ArcMap platform Figure 6 You can start using it by double clicking its icon in the ArcToolbox window ArcToolbox 3D Analyst Tools Analysis Tools Cartography Tools Conversion Tools Data Mana
16. gement Tools Example Geocoding Tools Geostatistical Analyst Tools y Inundation vulnerability Ap Linear Referencing Tools amp Spatial Analyst Tools Spatial Statistics Tools Figure 6 The ArcGis toolbox as it appears after the installation of the Inundation Vulnerability tool 31 4 2 Running the model To run the model double click on its icon in the Arc Toolbox The RVI icon will appear Figure 7 Figure 7 2 ArcToolbox 3D Analyst Tools Sp Analysis Tools Cartography Tools Conversion Tools Data Management Tools Example A Geocoding Tools A Geostatistical Analyst Tools Inundation_vulnerability Pa RVI x Sp Linear Referencing Tools simple model example Spatial Analyst Tools Kp Spatial Statistics Tools Tu run the model double click on its icon in the Arc Toolbox 32 Double click the RVI icon and the model will ask you to insert the path to the inundated buildings shapefile Figure 8 Look for the inundated buildings shapefile and click OK The model will start ArcToolbox amp 3D Analyst Tools amp Analysis Tools Qi Cartography Tools A Conversion Tools Data Management Tools Example Qi Geocoding Tools Qi Geostatistical analyst Tools Qi Inundation vulnerability RVI Inundated Buildings shp 5 D MEDINGEGNERIA Dottorato Syciney Ma
17. io that could occur in the Sydney region Whilst a tsunami is a low probability event the consequences would be significant Importantly a 5 metre run up is similar to what could be expected during an extreme storm surge on a high tide Therefore the vulnerability tool may easily be applied to storm surge inundation increasing its applicability 2 DATA NEEDED Input data required to run the model include high resolution aerial or satellite images a Digital Elevation Model with the best vertical accuracy and horizontal resolution as possible LIDAR data would be perfect an ESRI shapefile Saved as inundated buildings containing all the polygons associated with the buildings to be analysed and data related to a range of structural features for each building see below All the data must be georeferenced with respect to the same coordinate system 2 1 Orthorectified images Both aerial and high resolution satellite images such as Quickbird images or Ikonos are suitable for this analysis if they are georefernced and orthorectified These images can be used as a 10 geographical base to start building the GIS system For example if the shapefile of the buildings does not exist yet the buildings can be digitalized in ArcGIS once the images have been displayed to their correct coordinates 2 2 The Digital Elevation Model DEM A Digital Elevation Model is of paramount importance in understanding flow depth across
18. nerability from very low to very high The correspondence between RVI levels and 1 5 numerical classes is shown in Table 3 Table 3 Once RVI 1 5 has been calculated by the model the RVI field must be manually filled with text tags RVL1_5 1 1 8 1 8 2 6 2 6 3 4 8 4 4 2 4 2 5 RVI Note The RVI field can be filled selecting buildings by attributes selecting all the buildings having RVI 1 5 1 1 8 and typing the tag very low into their RVI field then doing the same for every RVI 1 5 class Buildings with a high or very high RVI tag are identified as the most vulnerable to inundations and if the scenario occurred these buildings would be expected to be completely destroyed 35 WV_1_5 contains the scores expressing the vulnerability of buildings to prolonged contact with water WV_1_5 ranges between 1 minimum vulnerability and 5 maximum vulnerability WV_1_5 contributes approximately 30 of the overall assessment of 4 5 WV 1 5 is a function of the percentage of floors including basement that would be inundated in every building SV 1 5 contains the scores expressing the structural vulnerability of buildings SV 1 5 scores range between 1 minimum structural vulnerability and 5 maximum structural vulnerability SV 1 5 contributes approximately 7096 of the overall assessment of RVI 1 5 and it is a functi
19. nother layer Iwant to select features from the following layer s Inundated Buildings Manly 9 Transport Road Centrelines BUS SHELTERS point BUS SHELTERS font point Shoreline Seawall ocean side 9 Admnistratives LGA Boundary region 9 Property boundaries CADASTRAL AUTH region M Only show selectable layers in this list that intersect hd SA ne KS We the Features in this layer e topography im V Use selected features 1 features selected Apply a buffer to the features in topography 1m of OK Apply Pee Figure 1 Selecting inundated buildings by location The Building Material And Technique Of Construction field name m Is the standardized score related to the main construction material categories for each building It ranges from 1 minimum vulnerability to 1 maximum vulnerability Table 1 In the field insert only the score associated with the building material The Number Of Stories there are two fields for this attribute stories and 5 The number of stories above the ground level basement are not considered here The number of stories and their corresponding scores are shown in Table 1 Insert the score under the field s and the number of stories 1 2 3 4 5 6 7 in the field number
20. ode for buildings under construction In case a building is used for more than one activity please type the code for each activity For example in the case of a residential and commercial building type res comm 16 Notes field name 5 Use this field to insert any additional information that can be used to identify other important features of the building such as building under construction ground floor given over to parking and or storage only the floor height is noticeably higher than the ground level name of the commercial activity within the building etc 21 Table 1 Values assigned to the seven factors influencing the structural vulnerability of a building 0 5 5 more than 5 4 stories 3 stories 2 stories 1 storey stories m reinforced double brick single brick timber OR concrete fibro g open plan open plan and 50 open plan not open plan but not open plan windows many windows f deep pile average depth shallow foundations foundations 3 foundations gt 5 stories stories 1 story so rounded OR square building rectangular square building lengthened triangular footprint with building footprint footprint OR rectangular building oblique orientation with the main rectangular with the building footprint OR lengthened side main side parallel to footprint with rectangular footprint perpendicular to the shoreline the main side with the main side the sho
21. on of the structural features of buildings field BV 1 5 the degree of protection that is provided by their surroundings field Prot 1 5 and the depth of the inundation For further information about factors influencing the structural vulnerability please refer to the final project report available from the SCCG BV 1 5 contains the scores expressing the structural vulnerability of buildings without the protection of building surroundings Scores range between 1 and 5 Scores depend on physical features of structures such as number of stories s building material m p foundation type f ground floor characteristics g shape and orientation of building 36 footprints so preservation conditions and the presence of heavy movable objects around the building mo For further information about the relative weight of these factors please refer to the final project report available from the SCCG Prot_1_5 contains scores representing the degree of protection provided to the building by its surroundings A score equal to 5 means that there is no protection while a score equal to 1 means that the degree of protection is maximum In that case maximum degree of protection the structural vulnerability of the building SV_1_5 will be strongly decreased 5 times The role of protection is thus very important in defining the final vulnerability level Protection can be provi
22. one underground level and all these levels would be completely submerged by water 19 14 15 Number of Units field name numb units An individual building may not have a discrete use It may be divided in to multiple units and the units may have different functions numb units is the number of residential or commercial or any other type of unit within a given building It is useful to divide units according to their use e g 3 commercial units 15 residential units 1 health unit This is not a factor used for the computation of the building vulnerability but it is very important in order to understand results of the model and may also be useful for understanding the vulnerability of the building occupants Building Use In this field a description of the use of each building should be given according to the following res is the code for residential buildings comm is the code for commercial buildings health is the code for heath buildings trans is the code for transport system buildings gov is the code for governmental buildings utilities is the code for utilities buildings 5 edu is the code for education buildings 20 recreation culture is the code for buildings for recreation activities sport cinema etc and cultural uses religion museum heritage buildings etc tourism is the code for hotels residence holiday houses etc unknown is the c
23. ore of each building is estimated as a weighted sum of two different components 1 the vulnerability of the carrying capacity of the building structure given by the horizontal hydrodynamic force associated with water flow and 2 the vulnerability of different building components due to their prolonged contact with water the internal and external plaster the fixtures the paving tiles the floors and electric appliances etc Given these two components the RVI score of every building in this study has been calculated using the following equation Relative Vulnerability Index RVI 2 3 x SV_1_5 1 3 x WV 1 5 where SV_1_5 is the standardized score from 1 to 5 for the structural vulnerability and WV_1_5 is the standardized score from 1 to 5 for the vulnerability to water intrusion When the model runs it calculates SV 1 5 WV_1_5 together with all the intermediate steps needed to obtain RVI All the outputs of the model are described in Section 4 3 For further information about the theoretical background for the method refer to the final project report available at http www sydneycoastalcouncils com au 1 4 The Inundation Scenario The scenario that has been used as the boundary condition to run the vulnerability assessment is a locally generated submarine landslide tsunami achieving a run up of 5 metres above sea level Such a tsunami equates to a credible worst case scenar
24. rable to the impact of catastrophic marine floods associated with tsunami and storm surges The future impacts of such floods will be worse than in the past because of climate related sea level rise and increased exposure at the coast Coastal planners and risk managers need innovative tools to undertake assessment of the vulnerability of buildings and infrastructure in order to be able to estimate probable maximum loss located within their areas of responsibility Such assessments will enable risk mitigation measures to be developed and challenges of long term sustainability to be addressed The aims of the project were to apply a newly developed GIS vulnerability assessment tool to selected coastal suburbs of Sydney 5 evaluate and quantify the vulnerability of buildings at those locations to a hypothetical tsunami or storm surge flood based on the latest scientific understanding produce maps to display the spatial distribution of vulnerable structures at a scale of 1 5000 to make recommendations about possible risk management strategies at those locations and to provide a tool kit for local government to undertake vulnerability assessment themselves 1 2 The User s Manual This manual together with the attached CD Rom provides a step by step guide that can be used to apply the method developed by us to other coastal areas This manual refers to the software ArcGIS 9 2 from ESRI which was used throughout the project Nevertheless users
25. reline OR parallel to the perpendicular to the slightly oblique shoreline shoreline mo buildings far from buildings buildings before buildings on a side of buildings Sources of along roads car park OR on a car park OR on behind large movable objects with many intersections intersections with car parks parked cars without parked cars many parked cars pc very poor poor average good excellent 22 Table 2 Scores assigned to the four factors influencing the level of protection of a building Prot Scores close to zero indicate an high protection level while scores equal to 1 indicate that the building is totally exposed to the water impact Prot_br building row gt 10th 7th 10th 4th 6th 2nd 3rd 1st Prot_nb natural barriers very high protection high protection average protection moderate protection no protection Prot_sw vertical and gt 5m vertical and 3 to vertical and 1 5 to vertical and 0 to sloped and 0 to 1 5m _ 5 3m 1 5m OR OR seawall height and shape sloped and 1 5 to no seawall 3m Prot_w height of the wall is height of the wall is height of the wall is height of the wall is height of the wall is from 80 to 100 from 60 to 80 from 40 to 60 from 20 to 4096 of from 0 to 20 of the DUIS around of the water depth of the water depth ofthe water depth the water depth water depth calculated by the mo
26. roubra GIS Vector Shape Inundated_buildings Inundated_Buildings shp 5 OK Cancel Environments Show Help gt gt Figure 8 First step to run the model selection of the input file 33 4 3 Outputs Once the model runs a number of new fields will be added to the inundated buildings attribute table Some are intermediate steps for the calculation of the final Relative Vulnerability Index scores while others are useful in the analysis and discussion of the results All the fields created by the model are listed and described here 1 5 15 the Relative Vulnerability Index score of the building in question In this field values have been standardized to a numerical scale ranging from 1 minimum vulnerability to 5 maximum vulnerability The RVI takes into consideration all the factors and criteria that contribute to building vulnerability during inundation It is a combination of the structural vulnerability of the building field SV 1 5 and the vulnerability given by prolonged contact with water field WV 1 5 RVI after the model run this field is still empty It is not an error This last field needs to be filled manually within the attribute table The RVI field is just a text field that has been created to enable a better visualization of results The numerical range of values of the field 34 4 5 must be divided into 5 equal subsequent classes expressing 5 different levels of vul
27. the inundation zone Using the scenario of a 5 m tsunami or storm surge the water depth in each point of the flooded area is given by Water Depth at the point 5 metres maximum tide level topographical elevation at A DEM having a vertical accuracy of at least one metre is required for an effective description of the inundation In order to apply the GIS numerical model users will need to insert the values of the water depth touching every single building inside the attribute table of the inundated buildings shapefile under the field water depth To do this it is necessary to convert the DEM into a polygon shapefile composed of different spatial overlays in the form of polygons each representing the spatial area 11 contained within an elevation range of 1m e g 2 3m AHD overlying the area within the elevation range 1 2m AHD and so on up to the maximum inundation depth for the study area This shapefile should be named water depth The conversion procedure depends on the starting format of the available DEM Normally if the DEM is in an ASCII format which is readable by ArcGIS 9 2 it can be transformed into a RASTER file using the ArcGIS conversion tool ASCII to RASTER Then the RASTER file can be converted to a polygon shapefile with the tool RASTER to polygon 2 3 The inundated buildings shapefile All the buildings that will be inundated in the flood scenario n
28. who do not have that software should be able to follow the overall approach which is described in detail in the project final report available from the SCCG at http www sydneycoastalcouncilsgroup com au using another GIS platform The CD Rom associated with this manual contains a GIS model that can be easily run through ArcGIS 9 2 The model uses as input a set of initial data and provides as output the Relative Vulnerability Index score of each building in the case study area In this manual readers will find information about the following topics detailed list of the initial data required to run the GIS model in ERSI ArcGIS 9 2 Some suggestions for gathering missing data via field surveys Instructions on how to install and run the GIS model Instructions for creating the vulnerability maps 1 3 The Method theoretical background The definition of vulnerability that has been adopted throughout this work is given by Mitchell 1997 and states that vulnerability is the susceptibility to injury or damage from hazards This model can automatically calculate a numerical index for each building which is referred to as the Relative Vulnerability Index RVI RVI ranges between 1 minimum and 5 maximum and 7 represents the relative vulnerability of each building to the inundation scenario used as the boundary condition see next paragraph According to the definition of vulnerability used here the RVI sc
29. y built to protect against high tides and storm surges can provide protection during a tsunami Darlymple and Kriebel 2005 If a building is located behind a seawall enter a score in the sw field according to Table 2 11 12 13 Natural Barriers field name PROT nb the presence of natural barriers such as coastal forests can significantly reduce the level of structural damage to buildings located landward of these natural barriers Matsutomi et al 2006 Olwig et al 2007 The degree of protection from natural barriers can be inferred though field surveys and aerial images Scores must be given to this field according to Table 2 Brick Wall around the building field name wall height individual walls located around building structures such as garden walls although not specifically constructed to provide protection from flooding do offer some protection from flood inundation Dominey Howes and Papathoma 2007 The degree of protection is dependent on the height of the wall compared to the depth of the inundation at the point where the building is located These data can only be gathered during field surveys Type in this field an approximate value of the wall height in metres The model will compare it with the water level expected to occur in that location Basement levels field name levs This is the number of floors located below the ground level A given building can have more than
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